Axial and appendicular body proportions for evaluation of limb and trunk asymmetry.

PubMed

Weinberg, Douglas S; Liu, Raymond W; Li, Samuel Q; Sanders, James O; Cooperman, Daniel R

2017-04-01

Background and purpose - When children with irregular body proportions or asymmetric limbs present, it may be unclear where the pathology is located. An improved understanding of the clinical ratio between upper extremity, lower extremity, and spine length may help elucidate whether there is disproportion between the trunk and limbs, and whether there is a reduction deficit of the shorter limb rather than hypertrophy of the longer limb. Patients and methods - We used the Brush Foundation study of child growth and development, which was a prospective, longitudinal study of healthy children between the 1930s and the 1950s, and we collected serial clinical measurements for 290 children at 3,326 visits. Children ranged from 2 to 20 years of age during the study period. Linear and quadratic regression were used to construct nomographs and 95% prediction intervals for anthropometric body proportions. Results - The maximum anterior superior iliac spine height to sitting height ratio occurred at 12.4 years in females and at 14.17 years in males. Overall, the ratio of arm length to sitting height was 0.76 (SD 0.06), the ratio of arm length to anterior superior iliac spine height was 0.76 (SD 0.03), and the ratio of anterior superior iliac spine height to sitting height was 0.98 (SD 0.13). When comparing ratios between arm length, anterior superior iliac spine height, and sitting height, the smallest variance between appendicular proportions was found in the arm length to anterior superior iliac spine height ratio. Interpretation - We recommend comparisons between total arm length and anterior superior iliac spine height to distinguish limb reduction deficits from hemi-hypertrophy, with sitting height being used only if combined upper and lower extremity discrepancy is noted.

Axial and appendicular body proportions for evaluation of limb and trunk asymmetry

PubMed Central

Weinberg, Douglas S; Liu, Raymond W; Li, Samuel Q; Sanders, James O; Cooperman, Daniel R

2017-01-01

Background and purpose When children with irregular body proportions or asymmetric limbs present, it may be unclear where the pathology is located. An improved understanding of the clinical ratio between upper extremity, lower extremity, and spine length may help elucidate whether there is disproportion between the trunk and limbs, and whether there is a reduction deficit of the shorter limb rather than hypertrophy of the longer limb. Patients and methods We used the Brush Foundation study of child growth and development, which was a prospective, longitudinal study of healthy children between the 1930s and the 1950s, and we collected serial clinical measurements for 290 children at 3,326 visits. Children ranged from 2 to 20 years of age during the study period. Linear and quadratic regression were used to construct nomographs and 95% prediction intervals for anthropometric body proportions. Results The maximum anterior superior iliac spine height to sitting height ratio occurred at 12.4 years in females and at 14.17 years in males. Overall, the ratio of arm length to sitting height was 0.76 (SD 0.06), the ratio of arm length to anterior superior iliac spine height was 0.76 (SD 0.03), and the ratio of anterior superior iliac spine height to sitting height was 0.98 (SD 0.13). When comparing ratios between arm length, anterior superior iliac spine height, and sitting height, the smallest variance between appendicular proportions was found in the arm length to anterior superior iliac spine height ratio. Interpretation We recommend comparisons between total arm length and anterior superior iliac spine height to distinguish limb reduction deficits from hemi-hypertrophy, with sitting height being used only if combined upper and lower extremity discrepancy is noted. PMID:27998211

Limb lengthening and peripheral nerve function—factors associated with deterioration of conduction

PubMed Central

2013-01-01

Background and purpose Limb lengthening is performed for a diverse range of orthopedic problems. A high rate of complications has been reported in these patients, which include motor and sensory loss as a result of nerve damage. We investigated the effect of limb lengthening on peripheral nerve function. Patients and methods 36 patients underwent electrophysiological testing at 3 points: (1) preoperatively, (2) after application of external fixator/corticotomy but before lengthening, and (3) after lengthening. The limb-length discrepancy was due to a congenital etiology (n = 19), a growth disturbance (n = 9), or a traumatic etiology (n = 8). Results 2 of the traumatic etiology patients had significant changes evident on electrophysiological testing preoperatively. They both deteriorated further with lengthening. 7 of the 21 patients studied showed deterioration in nerve function after lengthening, but not postoperatively, indicating that this was due to the lengthening process and not to the surgical procedure. All of these patients had a congenital etiology for their leg-length discrepancy. Interpretation As detailed electrophysiological tests were carried out before surgery, after surgery but before lengthening, and finally after completion of lengthening, it was possible to distinguish between the effects of the operation and the effects of lengthening on nerve function. The results indicate that the etiology, site (femur or tibia), and nerve (common peroneal or tibial) had a bearing on the risk of nerve injury and that these factors had a far greater effect than the total amount of lengthening. PMID:24171677

Staged lengthening arthroplasty for pediatric osteosarcoma around the knee.

PubMed

Kong, Chang-Bae; Lee, Soo-Yong; Jeon, Dae-Geun

2010-06-01

Orthopaedic oncologists often must address leg-length discrepancy after resection of tumors in growing patients with osteosarcoma. There are various alternatives to address this problem. We describe a three-stage procedure: (1) temporary arthrodesis, (2) lengthening by Ilizarov apparatus, and (3) tumor prosthesis. We asked (1) to what extent are affected limbs actually lengthened; (2) how many of the patients who undergo a lengthening procedure eventually achieve joint arthroplasty; and (3) can the three-stage procedure give patients a functioning joint with equalization of limb length? We reviewed 56 patients (younger than 14 years) with osteosarcoma who had staged lengthening arthroplasty between 1991 and 2004. Thirty-five of the 56 patients (63%) underwent soft tissue lengthening, and of these 35, 28 (50% of the original group of 56) had implantation of a mobile joint. Three of the 28 prostheses were later removed owing to infection after arthroplasty. The overall average length gained was 7.8 cm (range, 4-14 cm), and 25 (71%) of the 35 patients had a mobile joint at final followup. The average Musculoskeletal Tumor Society functional score was 23.2 (range, 15-28) and limb-length discrepancy at final followup was 2.6 cm (range, 0-6.5 cm). Although most mobile joints had an acceptable ROM (average, 74.2 degrees ; range, 35 degrees -110 degrees ), extension lag was frequent. Our approach is one option for skeletally immature patients, especially in situations where an expandable prosthesis is not available. However, this technique requires multiple stages and would be inappropriate for patients who cannot accept prolonged functional deficit owing to a limited lifespan or other reasons. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Melorheostosis in a pediatric patient.

PubMed

Schreck, Michael A

2005-01-01

Melorheostosis is a nonhereditary and uncommon condition that can affect both adults and children. It can appear on radiographs as increased sclerosis on bones of the upper and lower extremities and may mimic other bony conditions such as osteopoikilosis, osteopetrosis, arthrogryposis multiplex congenita, and osteopathia striata. The sclerotic appearance can differ greatly between adults and children. The skin and subcutaneous tissues may be affected by fibrosis, resulting in contractures of joints and limbs that lead to deformities and limb-length discrepancies. This article reviews the literature on melorheostosis and describes a case in a 10-year-old boy.

[A method to avoid lengthening lower limbs after total hip arthroplasty in patients with congenital short femoral neck].

PubMed

Chen, Tao; Shang, Xifu; He, Rui; Hu, Fei; Ge, Chang

2012-03-01

To investigate the method to avoid lengthening lower limbs after total hip arthroplasty in patients with congenital short femoral neck. The clinical data were analyzed retrospectively from 38 patients undergoing unilateral total hip arthroplasty between April 2005 and December 2010. There were 26 males and 12 females, aged 45-78 years (mean, 62.3 years). Among these cases, there were 11 cases of avascular necrosis of the femoral head, 17 cases of hip osteoarthritis, and 10 cases of femoral neck fracture. Before operation, 29 cases had leg length discrepancy; and the shortened length of the legs was 10-24 mm with an average of 14.5 mm by clinical measurement, and was 11-25 mm with an average of 14.7 mm by X-ray film measurement. The Harris score before operation was 44.0 +/- 3.6. At 1 day after operation, 3 cases had legs lengthening by clinical and X-ray film measurement; limb length difference less than 10 mm was regarded as equal limb length in the other 35 patients (92.1%). All incisions healed by first intention, and no complication of infection or lower limb deep venous thrombosis occurred. In 3 patients who had legs lengthening, 1 patient had abnormal gait and slight limping after increasing heel pad because the lower limb was lengthened by 16 mm, and 2 patients had slight limping. The other patients could walk normally and achieved pain relief of hip. Thirty-six patients were followed up 12-68 months (mean, 43.8 months). The Harris score was 86.7 +/- 2.3 after 6 months, showing significant difference (t = 3.260, P = 0.031) when compared with that before operation. The X-ray films showed no prosthetic loosening or subsidence. For patients with congenital short femoral neck during total hip arthroplasty, the surgeons should pay attention to osteotomy plane determination, limb length measurement, and use of the prosthesis with collar to avoid the lengthening lower limbs.

Application of monorail fixator for femoral gap nonunion.

PubMed

Agrawal, Hemendra-Kumar; Jaiman, Ashish; Khatkar, Vipin; Sharma, Vinod-Kumar

2014-01-01

Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration.

Femoral Reconstruction Using External Fixation

PubMed Central

Palatnik, Yevgeniy; Rozbruch, S. Robert

2011-01-01

Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD), limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD) and lateral distal femoral angle (LDFA) for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction. PMID:21991425

Decreasing an Offloading Device's Size and Offsetting Its Imposed Limb Length Discrepancy Lead to Improved Comfort and Gait.

PubMed

Crews, Ryan T; Candela, Joseph

2018-04-17

Patient adherence is a challenge in offloading diabetic foot ulcers (DFUs) with removable cast walkers (RCWs). The size and weight of an RCW, changes to gait, and imposed limb length discrepancies may all discourage adherence. This study sought to determine whether RCW size and provision of a contralateral limb lift affected users' comfort and gait. Twenty-five individuals at risk for DFUs completed several 20-m walking trials under five footwear conditions: bilateral standardized shoes, a knee-high RCW with shoe with or without an external shoe lift contralaterally, and an ankle-high RCW with shoe with or without an external shoe lift contralaterally. Perceived comfort ratings were assessed through the use of visual analog scales. Spatial and temporal parameters of gait were captured by an instrumented walkway, and plantar pressure was measured and recorded using pedobarographic insoles. The bilateral shoes condition was reported to be most comfortable; both RCW conditions without the lift were significantly less comfortable ( P < 0.01). In contrast to the ankle-high RCW, the knee-high RCW resulted in significantly slower walking (5.6%; P < 0.01) but greater offloading in multiple forefoot regions of the offloaded foot (6.8-8.1%; P < 0.01). Use of the contralateral shoe lift resulted in significantly less variability in walking velocity (52.8%; P < 0.01) and reduced stance time for the offloaded foot (2.6%; P = 0.01), but it also reduced offloading in multiple forefoot regions of the offloaded foot (3.7-6.0%; P < 0.01). Improved comfort and gait were associated with the ankle-high RCW and contralateral limb lift. Providing this combination to patients with active DFUs may increase offloading adherence and subsequently improve healing. © 2018 by the American Diabetes Association.

Trochanteric bursitis after total hip arthroplasty: incidence and evaluation of response to treatment.

PubMed

Farmer, Kevin W; Jones, Lynne C; Brownson, Kirstyn E; Khanuja, Harpal S; Hungerford, Marc W

2010-02-01

We examined the efficacy of corticosteroid injection as treatment for postarthroplasty trochanteric bursitis and the risk factors for failure of nonoperative treatment. There were 32 (4.6%) cases of postsurgical trochanteric bursitis in 689 primary total hip arthroplasties. Of the 25 hips with follow-up, 11 (45%) required multiple injections. Symptoms resolved in 20 (80%) but persisted in 5. We found no statistically significant differences between patients who did and did not develop trochanteric bursitis, or between those who did and did not respond to treatment. There was a trend toward younger age and greater limb-length discrepancy in nonresponders. In conclusion, (1) corticosteroid injection(s) for postoperative trochanteric bursitis is effective; and (2) nonoperative management may be more likely to fail in young patients and those with leg-length discrepancy. 2010 Elsevier Inc. All rights reserved.

Advanced concepts in knee arthrodesis.

PubMed

Wood, Jennifer H; Conway, Janet D

2015-03-18

The aim is to describe advanced strategies that can be used to diagnose and treat complications after knee arthrodesis and to describe temporary knee arthrodesis to treat infected knee arthroplasty. Potential difficult complications include nonunited knee arthrodesis, limb length discrepancy after knee arthrodesis, and united but infected knee arthrodesis. If a nonunited knee arthrodesis shows evidence of implant loosening or failure, then bone grafting the nonunion site as well as exchange intramedullary nailing and/or supplemental plate fixation are recommended. If symptomatic limb length discrepancy cannot be satisfactorily treated with a shoe lift, then the patient should undergo tibial lengthening over nail with a monolateral fixator or exchange nailing with a femoral internal lengthening device. If a united knee arthrodesis is infected, the nail must be removed. Then the surgeon has the option of replacing it with a long, antibiotic cement-coated nail. The authors also describe temporary knee arthrodesis for infected knee arthroplasty in patients who have the potential to undergo insertion of a new implant. The procedure has two goals: eradication of infection and stabilization of the knee. A temporary knee fusion can be accomplished by inserting both an antibiotic cement-coated knee fusion nail and a static antibiotic cement-coated spacer. These advanced techniques can be helpful when treating difficult complications after knee arthrodesis and treating cases of infected knee arthroplasty.

Knee arthrodesis with a press-fit modular intramedullary nail without bone-on-bone fusion after an infected revision TKA.

PubMed

Iacono, Francesco; Bruni, Danilo; Lo Presti, Mirco; Raspugli, Giovanni; Bondi, Alice; Sharma, Bharat; Marcacci, Maurilio

2012-10-01

Knee arthrodesis can be an effective treatment after an infected revision Total Knee Arthroplasty (TKA). The main hypothesis of this study is that a two-stage arthrodesis of the knee using a press-fit, modular intramedullary nail and antibiotic loaded cement, to fill the residual gap between the bone surfaces, prevents an excessive limb shortening, providing satisfactory clinical and functional results even without direct bone-on-bone fusion. The study included 22 patients who underwent knee arthrodesis between 2004 and 2009 because of recurrent infection following revision-TKA (R-TKA). Clinical and functional evaluations were performed using the Visual Analogue Scale (VAS) and the Lequesne Algofunctional Score. A postoperative clinical and radiographical evaluation of the residual limb-length discrepancy was conducted by three independent observers. VAS and LAS results showed a significant improvement with respect to the preoperative condition. The mean leg length discrepancy was less than 1cm. There were three recurrent infections that needed further surgical treatment. This study demonstrated that reinfection after Revision of total knee Arthroplasty can be effectively treated with arthrodesis using a modular intramedullary nail, along with an antibiotic loaded cement spacer and that satisfactory results can be obtained without direct bone-on-bone fusion. Published by Elsevier B.V.

Advanced concepts in knee arthrodesis

PubMed Central

Wood, Jennifer H; Conway, Janet D

2015-01-01

The aim is to describe advanced strategies that can be used to diagnose and treat complications after knee arthrodesis and to describe temporary knee arthrodesis to treat infected knee arthroplasty. Potential difficult complications include nonunited knee arthrodesis, limb length discrepancy after knee arthrodesis, and united but infected knee arthrodesis. If a nonunited knee arthrodesis shows evidence of implant loosening or failure, then bone grafting the nonunion site as well as exchange intramedullary nailing and/or supplemental plate fixation are recommended. If symptomatic limb length discrepancy cannot be satisfactorily treated with a shoe lift, then the patient should undergo tibial lengthening over nail with a monolateral fixator or exchange nailing with a femoral internal lengthening device. If a united knee arthrodesis is infected, the nail must be removed. Then the surgeon has the option of replacing it with a long, antibiotic cement-coated nail. The authors also describe temporary knee arthrodesis for infected knee arthroplasty in patients who have the potential to undergo insertion of a new implant. The procedure has two goals: eradication of infection and stabilization of the knee. A temporary knee fusion can be accomplished by inserting both an antibiotic cement-coated knee fusion nail and a static antibiotic cement-coated spacer. These advanced techniques can be helpful when treating difficult complications after knee arthrodesis and treating cases of infected knee arthroplasty. PMID:25793160

Treatment of osteosarcoma around the knee in skeletally immature patients

PubMed Central

Yao, Weitao; Cai, Qiqing; Wang, Jiaqiang; Gao, Songtao

2017-01-01

Limb sparing surgery in growing young patients with malignant tumors is difficult as invasion of the physis by the tumor or surgical resection through the metaphysis may cause significant limb discrepancy following surgery. At present, hinged tumor prosthesis or biological reconstructions are the main methods following tumor resection in these patients. The aim of the present study was to assess different procedures for the treatment of osteosarcoma around knee joints in immature patients. A retrospective study of 56 patients (<15 years old, open physis) who had been treated for osteosarcoma around the knee joint between January 2007 and December 2015 was performed. Clinical data collected included patient demographics (age at diagnosis, sex and date of diagnosis), tumor characteristics [location, Enneking stage and subtype on magnetic resonance imaging (MRI)], treatment (response to neoadjuvant chemotherapy and type of primary surgery) and clinical outcomes (limb function, discrepancy and overall survival). The median age at the time of diagnosis was 12.14 years (range, 3–15 years). There were 32 male patients (57.1%). A total of 41 (82%) tumors were located at the distal femur, and 15 (18%) at the proximal tibia. A total of 49 (87.5%) patients were diagnosed with stage IIB tumors, and 7 (12.5%) had stage III, according to the Enneking stage classification. Different surgical methods, including amputation, rotation-plasty, endoprosthesis and biological instructions (e.g., allograft) were performed according to MRI type classification. During follow-up, 21 patients (37.5%) succumbed to disease. The Musculoskeletal Tumor Society score ranged from excellent to fair functional result. Recurrence (2 cases, 16.67%) and infection (2, cases, 16.67%) were the main complications following endoprosthesis replacement, while delayed union (12 cases, 57.14%) and fracture (3 cases, 14.29%) were the main causes for biological reconstructions. Limb-length discrepancy ranged from 0–10 cm in limb-saving surgery. The overall survival rate was 57.66% with different cohorts in Enneking stages IIB and III, with or without involvement of the physis and different cycles of chemotherapy. Results of the present study indicated that different limb saving surgeries, including epiphysis/physis preservation with biological construction in patients with MRI types I to III and endoprosthetic/osteoarticular reconstruction in patients with MRI types IV and V, are useful in the management of osteosarcoma in growing young patients with proper surgery indications, and knee joint function was maintained with acceptable complications including limb discrepancy, delayed union, infection, recurrence and fracture. PMID:29113159

Arthrodesis After Infected Revision TKA: Retrospective Comparison of Intramedullary Nailing and External Fixation.

PubMed

Iacono, Francesco; Francesco, Iacono; Raspugli, Giovanni Francesco; Francesco, Raspugli Giovanni; Bruni, Danilo; Danilo, Bruni; Lo Presti, Mirco; Mirco, Lo Presti; Sharma, Bharat; Bharat, Sharma; Akkawi, Ibrahim; Ibrahim, Akkawi; Marcacci, Maurilio; Maurilio, Marcacci

2013-10-01

Infection after revision total knee arthroplasty (TKA) for previous septic TKA can be a challenging problem to treat due to loss of bone stock and soft tissue integrity. In these cases, arthrodesis is a well-recognized salvage procedure. The aim of this retrospective study was to compare the results as described by a Visual Analogue Scale (VAS) and the Lequesne Algofunctional Score (LAS) of knee arthrodeses performed by using either an external fixator (EF) or an intramedullary nail (IM). The study included 34 knee arthrodesis divided in two groups: first group included 12 patients treated with EF and the second group of 22 patients dealt with IM nail. Clinical and functional evaluation was performed using the VAS and the LAS. Full-length radiographs were used to verify limb length discrepancy. VAS and LAS results showed a substantial improvement relative to preoperative condition in both groups. However, the LAS was significantly better in the IM nail group. The mean leg length discrepancy was significantly greater (4.5 cm) in the first group than in the second one (0.8 cm). No recurrence of infection was observed in the EF group while there were three recurrent infections in the IM nail group. Our study supported the existing literature and found that reinfection after revision TKA can be effectively treated with arthrodesis. In presence of massive bone loss, we recommend arthrodesis with IM nail used as an endoprosthesis, without bone-on-bone fusion, to produce a stable and painless knee, while preserving the limb length. Use of an IM nail allowed us to get a better functional result than EF.

Three-dimensional reduction and finite element analysis improves the treatment of pelvic malunion reconstructive surgery

PubMed Central

Kurz, Sascha; Pieroh, Philipp; Lenk, Maximilian; Josten, Christoph; Böhme, Jörg

2017-01-01

Abstract Rationale: Pelvic malunion is a rare complication and is technically challenging to correct owing to the complex three-dimensional (3D) geometry of the pelvic girdle. Hence, precise preoperative planning is required to ensure appropriate correction. Reconstructive surgery is generally a 2- or 3-stage procedure, with transiliac osteotomy serving as an alternative to address limb length discrepancy. Patient concerns: A 38-year-old female patient with a Mears type IV pelvic malunion with previous failed reconstructive surgery was admitted to our department due to progressive immobilization, increasing pain especially at the posterior pelvic arch and a leg length discrepancy. The leg discrepancy was approximately 4 cm and rotation of the right hip joint was associated with pain. Diagnosis: Radiography and computer tomography (CT) revealed a hypertrophic malunion at the site of the previous posterior osteotomy (Mears type IV) involving the anterior and middle column, according to the 3-column concept, as well as malunion of the left anterior arch (Mears type IV). Interventions: The surgery was planned virtually via 3D reconstruction, using the patient's CT, and subsequently performed via transiliac osteotomy and symphysiotomy. Finite element method (FEM) was used to plan the osteotomy and osteosynthesis as to include an estimation of the risk of implant failure. Outcomes: There was not incidence of neurological injury or infection, and the remaining leg length discrepancy was ≤ 2 cm. The patient recovered independent, pain free, mobility. Virtual 3D planning provided a more precise measurement of correction parameters than radiographic-based measurements. FEM analysis identified the highest risk for implant failure at the symphyseal plate osteosynthesis and the parasymphyseal screws. No implant failure was observed. Lessons: Transiliac osteotomy, with additional osteotomy or symphysiotomy, was a suitable surgical procedure for the correction of pelvic malunion and provided adequate correction of leg length discrepancy. Virtual 3D planning enabled precise determination of correction parameters, with FEM analysis providing an appropriate method to predict areas of implant failure. PMID:29049196

[Case-control study on methods of limb length control in hip arthroplasty].

PubMed

Zhang, Yang-yang; Zuo, Jian-lin; Gao, Zhong-li

2016-02-01

To introduce a new measuring tool for measuring postoperative limb length exactly, and to provide a convenient and effective method to control limb length after total hip replacement. From January 2013 to September 2014, 102 patients undergoing primary unilateral hip replacement were divided into two groups: experimental group and control group. There were 51 patients in the experimental group, including 25 males and 26 females, ranging in age from 37 to 92 years old, with an average of 60.41 years old. The patients in experimental group were treated with new method to control limb length. Other 51 patients in the control group, including 27 males and 24 females, ranging in age from 35 to 87 years old, with an average of 61.00 years old. The patients in the control group were treated with normal methods such as shuck test or limb touching. All the patients were operated by the same experienced surgeon. In the experimental group,total hip arthroplasties (THA) were performed on 35 patients with avascular necrosis of the femoral head or femoral neck fracture, and 16 patients were treated with hemiarthroplasty (HA). In the control group, 38 patients received THA and 13 patients received HA. On the anterior-posterior X-ray radiograph, several indexes were measured as follows: the distance of bilateral femoral offset (a), the height from tip of great trochanter to the rotation center of the femoral head (b) and the vertical distance between the top of the minor trochanter and the two tear drops line (c). The leg length discrepancy can be assessed with three parameters as follows: d1, the absolute value of the difference between the bilateral a values; d2, the difference between the bilateral b values; d3, the difference between the bilateral c values. The SPSS 21.0 was applied for the statistical analysis. In the experimental and control groups, d1 were 4.49 mm and 7.32 mm (P = 0.013); d2 were 2.37 mm and 4.32 mm (P = 0.033); d3 were 3.32 mm and 6.08 mm (P = 0.031). The values of d1, d2 and d3 in the experimental group were significant smaller than those in the control group. The new measuring tool and method can be used to control the limb length and offset effectively during operation.

[Arthrodesis without bone fusion with an intramedullary modular nail for revision of infected total knee arthroplasty].

PubMed

Miralles-Muñoz, F A; Lizaur-Utrilla, A; Manrique-Lipa, C; López-Prats, F A

2014-01-01

To evaluate the outcome of knee fixation without bone fusion using an intramedullary modular nail and interposed cement. Retrospective study of 29 infected total knee arthroplasties with prospective data collection and a mean follow-up of 4.2 years (3-5). Complications included 2 recurrent infections, 1 peri-implant fracture, and 1 cortical erosion due to the tip of the femoral component. All of these were revised with successful results. The mean limb length discrepancy was 0.8 cm, with 24<1cm. Twenty-five patients reported no pain. The mean WOMAC-pain was 86.9, WOMAC-function 56.4, SF12-physical 45.1, and SF12-mental 53.7. Four patients needed a walking frame, and only two were dependent for daily activities. The Endo-Model Link nail is an effective method for knee fixation that restores the anatomical alignment of the limb with adequate leg length. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

Tibial lengthening using a reamed type intramedullary nail and an Ilizarov external fixator

PubMed Central

Kim, Hayoung; Kim, Kap Jung; Ahn, Jae Hoon; Choy, Won Sik; Kim, Yong In; Koo, Jea Yun

2008-01-01

The aim of this study was to evaluate the efficacy of tibial lengthening using a reamed type intramedullary nail and an Ilizarov external fixator for the treatment of leg length discrepancy or short stature. This retrospective study was performed on 18 tibiae (13 patients) in which attempts were made to reduce complications. We used an Ilizarov external fixator and a nail (10 mm diameter in 17 tibiae and 11 mm in one tibia) in combination. Average limb lengthening was 4.19 cm (range, 2.5–5.5). The mean duration of external fixation was 12.58 days per centimetre gain in length, and the mean consolidation index was 40.53 (range, 35.45–51.85). All distracted segments healed spontaneously without refracture or malalignment. Gradual limb lengthening using a reamed type intramedullary nail and circular external fixation in combination was found to be reliable and effective and reduced external fixation time with fewer complications. PMID:18415098

Estimating the hemodynamic influence of variable main body-to-iliac limb length ratios in aortic endografts.

PubMed

Georgakarakos, Efstratios; Xenakis, Antonios; Georgiadis, George S

2018-02-01

We conducted a computational study to assess the hemodynamic impact of variant main body-to-iliac limb length (L1/L2) ratios on certain hemodynamic parameters acting on the endograft (EG) either on the normal bifurcated (Bif) or the cross-limb (Cx) fashion. A customary bifurcated 3D model was computationally created and meshed using the commercially available ANSYS ICEM (Ansys Inc., Canonsburg, PA, USA) software. The total length of the EG, was kept constant, while the L1/L2 ratio ranged from 0.3 to 1.5 in the Bif and Cx reconstructed EG models. The compliance of the graft was modeled using a Fluid Structure Interaction method. Important hemodynamic parameters such as pressure drop along EG, wall shear stress (WSS) and helicity were calculated. The greatest pressure decrease across EG was calculated in the peak systolic phase. With increasing L1/L2 it was found that the Pressure Drop was increasing for the Cx configuration, while decreasing for the Bif. The greatest helicity (4.1 m/s2) was seen in peak systole of Cx with ratio of 1.5 whereas its greatest value (2 m/s2) was met in peak systole in the Bif with the shortest L1/L2 ratio (0.3). Similarly, the maximum WSS value was highest (2.74Pa) in the peak systole for the 1.5 L1/L2 of the Cx configuration, while the maximum WSS value equaled 2 Pa for all length ratios of the Bif modification (with the WSS found for L1/L2=0.3 being marginally higher). There was greater discrepancy in the WSS values for all L1/L2 ratios of the Cx bifurcation compared to Bif. Different L1/L2 rations are shown to have an impact on the pressure distribution along the entire EG while the length ratio predisposing to highest helicity or WSS values is also determined by the iliac limbs pattern of the EG. Since current custom-made EG solutions can reproduce variability in main-body/iliac limbs length ratios, further computational as well as clinical research is warranted to delineate and predict the hemodynamic and clinical effect of variable length ratios.

Single Stage Tibial Osteotomy and Long Stem Total Knee Arthroplasty to Correct Adverse Consequences of Unequal Tibial Lengthening with an Ilizarov Circular Fixator.

PubMed

Fletcher, M D

2015-01-01

Correction of limb alignment or length discrepancy by circular external fixation is an accepted technique which relies on the correct biomechanical application of the frame and precise corrections which are frequently delegated to the patient to perform. Errors can occur in the execution of the correction by the patient and may result in significant deformity that requires remedial intervention. A 67 Caucasian female underwent multifocal limb reconstruction of the lower limb utilising a complex Ilizarov frame. Attendance at follow-up visits did not occur and the patient presented at 6 months with severe deformity due to incorrect execution of the correction protocol which resulted in a 45 degree varus deformity of the tibia. Subsequent correction via acute tibial osteotomy and stabilisation with a stemmed total knee replacement resulted in a good outcome. Patient compliance with post-operative management is paramount with distraction osteogenesis and should be ensured prior to embarking on lengthening or deformity correction.

Radiographic parameters improve lower extremity prosthetic alignment.

PubMed

Mooney, Ryan; Carry, Patrick; Wylie, Erin; Schultz, Abby; McNair, Bryan; Page, Carol; Biffl, Susan; Heare, Travis

2013-12-01

The goal of prosthetic fitting is to provide comfort and functionality to the patient. It is thought that incorporating the use of standing anterior-posterior long leg radiographs (LLR) into the fitting of lower extremity prostheses will provide an objective guide when making adjustments, and be a better assessment of alignment. This study compares prosthetic alignment before and after radiography-guided adjustments. This retrospective study was performed at a multidisciplinary amputee clinic on patients with congenital and/or acquired limb deficiencies. Their prosthetic alignment was evaluated by LLR and adjusted as needed. Satisfactory alignment was defined as a mechanical axis angular deviation of ≤1° and a leg length discrepancy of ≤10 mm. A total of 45 unique prostheses from 24 subjects (10 female and 14 male) were included. Post-adjustment radiographs were obtained from 29 prostheses. After the initial prosthetic fitting, the probability of a satisfactory fit was 20.0 % (95 % CI 10.9-34.9 %). Following the baseline adjustment, the probability of a satisfactory fit improved to 53.3 % (95 % CI 37.5-70.9 %). After adjustment number 4, the probability of a satisfactory fit further improved to 76.7 % (95 % CI 41.9-98.0 %). There were also significant improvements in distal offset distance (p = 0.0040) and leg length discrepancy (p = 0.0206). The distal offset distance decreased by an average of 10.7 mm (95 % CI 3.6-17.8), and leg length discrepancy decreased by an average of 3.0 mm (95 % CI 00.48-5.5). The addition of LLRs to existing fitting methods significantly improves prosthetic alignment and length.

Percutaneous epiphysiodesis using transphyseal screws for limb-length discrepancies: high variability among growth predictor models.

PubMed

Monier, Bryan C; Aronsson, David D; Sun, Michael

2015-10-01

Percutaneous epiphysiodesis using transphyseal screws (PETS) was developed as a minimally invasive outpatient procedure to address limb-length discrepancy (LLD) that allowed immediate postoperative weight bearing and was potentially reversible by removing the screws. The aims of our study were to report our results using PETS for LLD and evaluate the accuracy of three growth predictor models. Sixteen patients with an average age of 14 years were treated for LLD using PETS. Thirteen patients had screws inserted in a parallel fashion and 3 had crossed screws. We compared the predicted LLD at skeletal maturity using the three growth predictor methods with the actual LLD at skeletal maturity and preoperative LLD with the final LLD at skeletal maturity. The mean LLD at skeletal maturity between the predicted and final measurements was 0.2 cm using the Green-Anderson method, 1.4 cm using the Moseley method, and -0.1 cm using the Paley method. The mean preoperative LLD of 3.1 cm was corrected to 1.7 cm at skeletal maturity (p < 0.001). Six patients complained of pain over the screw heads; however, no patient developed an infection or angular deformity. The three growth predictor methods predicted the final LLD within an average of 1.4 cm, but there was high variability. Although PETS improved the LLD by a mean of 1.4 cm, we believe the results would have been better if PETS was performed at an earlier skeletal age.

Depression and anxiety before and after limb length discrepancy correction in patients with unilateral developmental dysplasia of the hip.

PubMed

Liu, Ruiyu; Li, Yongwei; Fan, Lihong; Mu, Mingchao; Wang, Kunzheng; Song, Wei

2015-12-01

Limb length discrepancy (LLD) is common in patients with developmental dysplasia of the hip (DDH) and may influence the psychological status of these patients. The present study aims to investigate depression and anxiety in DDH patients with different extents of LLD and to assess the effect of LLD correction on these two psychological factors. 161 patients with DDH were recruited and divided into two groups based on whether they could perceive LLD preoperatively. The patients who could not perceive LLD were assigned to group N, and those who could perceive LLD were assigned to group P. Depression/anxiety, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and LLD were assessed one week before, six months and two years after total hip arthroplasty (THA). Depression and anxiety were significantly higher in group P patients compared to group N patients. The patients in group N presented significant improvement in depression and anxiety six months after arthroplasty, while DDH patients in group P did two years after arthroplasty. Correlation analyses revealed their improvement was associated with pain relief and improved hip function in both groups of patients and was also related to changes in the perception of LLD in group P patients. Depression and anxiety levels were higher in DDH patients with perceived LLD. Their improvement was related to pain relief and improved hip function following THA. In DDH patients with perceived LLD, a change in the perception of LLD also played a part in their improvement. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of a Mobile Application for Multiplier Method Growth and Epiphysiodesis Timing Predictions.

PubMed

Wagner, Pablo; Standard, Shawn C; Herzenberg, John E

The multiplier method (MM) is frequently used to predict limb-length discrepancy and timing of epiphysiodesis. The traditional MM uses complex formulae and requires a calculator. A mobile application was developed in an attempt to simplify and streamline these calculations. We compared the accuracy and speed of using the traditional pencil and paper technique with that using the Multiplier App (MA). After attending a training lecture and a hands-on workshop on the MM and MA, 30 resident surgeons were asked to apply the traditional MM and the MA at different weeks of their rotations. They were randomized as to the method they applied first. Subjects performed calculations for 5 clinical exercises that involved congenital and developmental limb-length discrepancies and timing of epiphysiodesis. The amount of time required to complete the exercises and the accuracy of the answers were evaluated for each subject. The test subjects answered 60% of the questions correctly using the traditional MM and 80% of the questions correctly using the MA (P=0.001). The average amount of time to complete the 5 exercises with the MM and MA was 22 and 8 minutes, respectively (P<0.0001). Several reports state that the traditional MM is quick and easy to use. Nevertheless, even in the most experienced hands, performing the calculations in clinical practice can be time-consuming. Errors may result from choosing the wrong formulae and from performing the calculations by hand. Our data show that the MA is simpler, more accurate, and faster than the traditional MM from a practical standpoint. Level II.

Infection Following Total Joint Arthroplasty Is the Main Cause of Litigation: Data From One Metropolitan Area.

PubMed

Kheir, Michael M; Rondon, Alexander J; Woolsey, Alexandra; Hansen, Heather; Tan, Timothy L; Parvizi, Javad

2018-05-01

A prior survey of members of the American Association of Hip and Knee Surgeons revealed that 78% of responding surgeons were named as a defendant in at least 1 lawsuit, and 69% of these lawsuits were dismissed or settled out of court. The most common sources of litigation were nerve injury, limb-length discrepancy, and infection. This study examined common reasons for lawsuits after total joint arthroplasty (TJA) in a single metropolitan area. A retrospective review of lawsuits filed between 2009 and 2015 in a 5-county metropolitan area was performed, including 30 hospitals and 113 TJA surgeons. Complaints underwent a manual review to determine the number of lawsuits and the specific allegations filed against each surgeon. Thirty-one (27.4%) surgeons were named as a defendant in at least 1 lawsuit. Eighty-three total lawsuits were filed during the period, 50 of which were dismissed or settled outside of court. Top reasons for lawsuits were, in descending order, infection, nerve injury, chronic pain, vascular injury, periprosthetic fracture, retention of foreign body, dislocation, limb-length discrepancy, venous thromboembolism, loosening, compartment syndrome, and other medical complaints. Infection appears to be the basis of most lawsuits after TJA. Surgeons should be aware of the potential for a lawsuit for complications and should strive to better communicate with patients regarding preoperative informed consent and disclosure after adverse events. Surgeons should minimize performing surgery in patients at high risk of complications, such as patients with a higher likelihood of developing postoperative infection or patients on chronic pain medications. Copyright © 2017 Elsevier Inc. All rights reserved.

New method of limb deformities correction in children.

PubMed Central

Atar, D.; Lehman, W. B.; Grant, A. D.; Strongwater, A.; Frankel, V. H.; Posner, M.; Golyakhovsky, V.

1992-01-01

A new "bloodless" technique (Ilizarov) was used to correct 36 limb deformities in 29 children. There were six leg length discrepancies, five achondroplasias, four deformed feet, five joint contractures, one rotational deformity of tibia, and in three the apparatus was used as an external fixator after corrective osteotomy. Lengthening was accomplished in 15 of the 16 procedures (93%). Average increase in femur length was 10 cm (32%), in tibial length 7.5 cm (30%), in humerus 11 cm (40%). Bony union was achieved in two out of five pseudoarthroses. Four deformed feet were fully corrected. Joint contractures were corrected in four out of five. The complication rate is as high as in other methods but with the Ilizarov apparatus, longer segments of bone were lengthened and more complex deformities were treated. Complications lessened as experience was gained. Images Fig. 1a,b Fig. 1 Fig. 1c Fig. 1d Fig. 1e Fig. 2a Fig. 2b Fig. 2c Fig. 2d Fig. 2e Fig. 3a Fig. 3b Fig. 3c Fig. 3d Fig. 4a Fig. 4b Fig. 4c Fig. 4d Fig. 4e Fig. 5a Fig. 5b Fig. 5c Fig. 5d PMID:1490205

Use of vascularised free fibula in limb reconstruction (for non-malignant defects).

PubMed

Hameed, Shahid; Ehtesham-ul-haq, Rana Hassan Javaid; Ahmed, Rao Saood; Majid, Abdul; Waqas, Muhammad; Aslam, Ayesha; Yusuf, Omamah; Butt, Ahsin Masood; Ali, Ghazanfar

2013-12-01

The case series was conducted at the Department of Plastic Surgery, Combined Military Hospital, Rawalpindi, from June 2009 to May 2011, and comprised 19 patients in whom free fibula flap was performed for upper and lower limb reconstruction, using SPSS 16. Results showed that flap survival was 100%. One (5.2%) flap was re-explored for venous congestion and was salvaged. One (5.2%) patient of congenital pseudoarthrosis of tibia had a fracture of the fibula and was treated with external fixation. Average follow up was 8 months. Mean union time and full weight-bearing was 6.5 +/- 1.34 months (range 3-8 months) and 9 months, respectively. No recurrence of pseudoathrosis was observed until the last follow up, with only a 1.5 cm length discrepancy in one patient. The results proved that a microvascular free fibular flap heals rapidly, causes early functional recovery and it can be raised as an osteocutaneous flap.

Limb length inequality: clinical implications for assessment and intervention.

PubMed

Brady, Rebecca J; Dean, John B; Skinner, T Marc; Gross, Michael T

2003-05-01

The purpose of this paper is to review relevant literature concerning limb length inequalities in adults and to make recommendations for assessment and intervention based on the literature and our own clinical experience. Literature searches were conducted in the MEDLINE, PubMed, and CINAHL databases. Limb length inequality and common classification criteria are defined and etiological factors are presented. Common methods of detecting limb length inequality include direct (tape measure methods), indirect (pelvic leveling), and radiological techniques. Interventions include shoe inserts or external shoe lift therapy for mild cases. Surgery may be appropriate in severe cases. Little agreement exists regarding the prevalence of limb length inequality, the degree of limb length inequality that is considered clinically significant, and the reliability and validity of assessment methods. Based on correlational studies, the relationship between limb length inequality and orthopaedic pathologies is questionable. Stronger support for the link between low back pain (LBP) and limb length inequality is provided by intervention studies. Methods involving palpation of pelvic landmarks with block correction have the most support for clinical assessment of limb length inequality. Standing radiographs are suggested when clinical assessment methods are unsatisfactory. Clinicians should exercise caution when undertaking intervention strategies for limb length inequality of less than 5 mm when limb length inequality has been identified with clinical techniques. Recommendations are provided regarding intervention strategies.

Congenital deformity of the paw in a captive tiger: case report

PubMed Central

2012-01-01

Background The aim of this report was to describe the clinical signs, diagnostic approach, treatment and outcome in the case of a tiger with a deformity of the paw. Case presentation A 1.5-year-old tiger (Panthera tigris) was presented with lameness of the left thoracic limb. A deformity involving the first and second metacarpal bones, and a soft tissue separation between the second and third metacarpal bones of the left front paw were observed. The second digit constantly struck the ground during locomotion. Based on the physical and radiographic evaluations, a diagnosis of ectrodactyly was made. A soft tissue reconstruction of the cleft with excision of both the second digit and distal portion of the second metacarpal bone was performed. Marked improvement of the locomotion was observed after surgical treatment, although the tiger showed a low degree of lameness probably associated with the discrepancy in length between the thoracic limbs. Conclusion This report shows a rare deformity in an exotic feline that it is compatible to ectrodactyly. Reconstructive surgery of the cleft resulted in significant improvement of limb function. PMID:22747639

Dual 8-plate technique is not as effective as ablation for epiphysiodesis about the knee.

PubMed

Stewart, Daniel; Cheema, Asad; Szalay, Elizabeth A

2013-12-01

Lower extremity length inequality can be problematic in children and is often addressed surgically. Several techniques have traditionally been utilized for epiphysiodesis, the goal being physeal ablation. Recently, 8-plates, initially developed for hemiepiphysiodesis, have been extended to epiphysiodesis by placing the plates on both medial and lateral sides of the physis. No prior studies have compared 8-plates with physeal ablation techniques. Between January 2003 and August 2009, 27 patients underwent epiphysiodesis surgery using either physeal ablation or 8-plate technique. Sixteen patients had physeal ablation and 11 had dual 8-plates. A retrospective chart review sought demographic data, outcomes, and complications. Radiographs were reviewed to measure pretreatment and posttreatment limb lengths. The median improvement in limb length discrepancy was 15.5 mm in the physeal ablation group and 4 mm in the 8-plate group (P<0.001). This difference was maintained following linear regression factoring out the effect of time (10.78 mm for ablation vs. 5.62 mm for 8-plates; P=0.016). There was no statistically significant difference in complication rate between the groups (P=0.112). Our study demonstrated physeal ablation to be a significantly superior treatment compared with dual 8-plates for epiphysiodesis. Despite theoretical advantages of 8-plates to perform epiphysiodesis about the knee, this study does not recommend the use of medial and lateral 8-plates to effect epiphysiodesis. Therapeutic III.

Correction of axial deformity during lengthening in fibular hypoplasia: Hexapodal versus monorail external fixation.

PubMed

Chalopin, A; Geffroy, L; Pesenti, S; Hamel, A; Launay, F

2017-09-01

Childhood fibular hypoplasia is a rare pathology which may or may not involve limb-length discrepancy and axial deformity in one or more dimensions. The objective of the present study was to compare the quality of the axial correction achieved in lengthening procedures by hexapodal versus monorail external fixators. The hypothesis was that the hexapodal fixator provides more precise correction. A retrospective multicenter study included 52 children with fibular hypoplasia. Seventy-two tibias were analyzed, in 2 groups: 52 using a hexapodal fixator, and 20 using a monorail fixator. Mean age was 10.2 years. Mean lengthening was 5.7cm. Deformities were analyzed and measured in 3 dimensions and classified in 4 preoperative types and 4 post-lengthening types according to residual deformity. Complete correction was achieved in 26 tibias in the hexapodal group (50%) and 2 tibias in the monorail group (10%). Mean post-correction mechanical axis deviation was smaller in the hexapodal group: 12.83mm, versus 14.29mm in the monorail group. Mean post-correction mechanical lateral distal femoral angle was 87.5° in the hexapodal group, versus 84.3° in the monorail group (P=0.002), and mean mechanical medial proximal tibial angle 86.9° versus 89.5°, respectively (P=0.015). No previous studies focused on this congenital pathology in lengthening and axial correction programs for childhood lower-limb deformity. The present study found the hexapodal fixator to be more effective in conserving or restoring mechanical axes during progressive bone lengthening for fibular hypoplasia. The hexapodal fixator met the requirements of limb-length equalization in childhood congenital lower-limb hypoplasia, providing better axial correction than the monorail fixator. IV. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A rationale for treating leg length discrepancy using photodynamic therapy

NASA Astrophysics Data System (ADS)

Bisland, Stuart K.; Johnson, Crystal; Diab, Mohammed; Wilson, Brian C.; Burch, Shane

2005-09-01

This study investigates the use of photodynamic therapy (PDT) in regulating bone development with a view to its potential role in treating Juvenile leg length discrepancy (LLD). Transgenic mice expressing the luciferase firefly gene upon activation of a promoter sequence specific to the vascular endothelial growth factor (VEGF) gene were subject to benzoporphyrin derivative monoacid (BPD-MA)-mediated PDT in the right, tibial epiphyseal growth plate at the age of 3 weeks. BPD-MA was administered intracardially (2mg/kg) followed 10 mins later by a laser light (690 +/- 5 nm) at a range of doses (5-27J, 50 mW output) delivered either as a single or repeat regimen (x2-3). Contra-lateral legs served as no-light controls. Further controls included animals that received light treatment in the absence of photosensitizer or no treatment. Mice were imaged for VEGF related bioluminescence (photons/sec/steradian) at t= 0, 24, 48, 72 h and 1-4 weeks post PDT. FaxitronTM x-ray images provided accurate assessment of bone morphometry. Upon sacrifice, the tibia and femur of the treated and untreated limbs were harvested, imaged and measured again and prepared for histology. A number of animals were sacrificed at 24 h post PDT to allow immunohistochemical staining for CD31, VEGF and hypoxia-inducible factor (HIF-1 alpha) within the bone. PDT-treated (10 J, x2) mice displayed enhanced bioluminescence at the treatment site (and ear nick) for up to 4 weeks post treatment while control mice were bioluminescent at the ear-nick site only. Repeat regimens provided greater shortening of the limb than the corresponding single treatment. PDT-treated limbs were shorter by 3-4 mm on average as compared to the contra lateral and light only controls (10 J, x2). Immunohistochemistry confirmed the enhanced expression VEGF and CD31 at 4 weeks post-treatment although no increase in HIF-1α was evident at either 24 h or 4 weeks post PDT treatment. Results confirm the utility of PDT to provide localized effects on bone development that may be applicable to other related skeletal deformities.

Recurrence of a Unicameral Bone Cyst in the Femoral Diaphysis.

PubMed

Kim, Hyun Se; Lim, Kyung Sup; Seo, Sung Wook; Jang, Seung Pil; Shim, Jong Sup

2016-12-01

Diaphyseal unicameral bone cysts of the long bone are generally known to originate near the growth plate and migrate from the metaphysis to the diaphysis during skeletal growth. In the case of unicameral bone cysts of diaphyseal origin, recurrence at the same location is extremely rare. We report a case of recurrence of a unicameral bone cyst in the diaphysis of the femur that developed 8 years after treatment with curettage and bone grafting. We performed bone grafting and lengthening of the affected femur with an application of the Ilizarov apparatus over an intramedullary nail to treat the cystic lesion and limb length discrepancy simultaneously.

Recurrence of a Unicameral Bone Cyst in the Femoral Diaphysis

PubMed Central

Kim, Hyun Se; Lim, Kyung Sup; Seo, Sung Wook; Jang, Seung Pil

2016-01-01

Diaphyseal unicameral bone cysts of the long bone are generally known to originate near the growth plate and migrate from the metaphysis to the diaphysis during skeletal growth. In the case of unicameral bone cysts of diaphyseal origin, recurrence at the same location is extremely rare. We report a case of recurrence of a unicameral bone cyst in the diaphysis of the femur that developed 8 years after treatment with curettage and bone grafting. We performed bone grafting and lengthening of the affected femur with an application of the Ilizarov apparatus over an intramedullary nail to treat the cystic lesion and limb length discrepancy simultaneously. PMID:27904734

Customization of biliopancreatic limb length to modulate and sustain antidiabetic effect of gastric bypass surgery.

PubMed

Pal, A; Rhoads, D B; Tavakkoli, A

2018-02-01

Although Roux-en-Y Gastric Bypass (RYGB) remains the most effective treatment for obesity and type 2 diabetes (T2D), many patients fail to achieve remission, or relapse. Increasing intestinal limb lengths of RYGB may improve outcomes, but the mechanistic basis for this remains unclear. We hypothesize biliopancreatic (BP) limb length modulates the antidiabetic effect of RYGB. Rats underwent RYGB with a 20-cm (RYGB-20cm) or 40-cm (RYGB-40cm) BP limb and were compared with control animals. After 2 and 4 wk, portal and systemic blood was sampled during intestinal glucose infusion. Portosystemic gradient was used to calculate intestinal glucose utilization (G util ), absorption (G absorp ), and hormone secretion. Intestinal morphology and gene expression were assessed. At 2 wk, G absorp progressively decreased with increasing BP limb length; this pattern persisted at 4 wk. G util increased ≈70% in both RYGB-20cm and -40cm groups at 2 wk. At 4 wk, G util progressively increased with limb length. Furthermore, Roux limb weight, and expression of hexokinase and preproglucagon, exhibited a similar progressive increase. At 4 wk, glucagon-like peptide-1 and -2 levels were higher after RYGB-40cm, with associated increased secretion. We conclude that BP limb length modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. Early postoperatively, a longer BP limb reduces G absorp . Later, G util , Roux limb hypertrophy, hormone secretion, and hormone levels are increased with longer BP limb. Sustained high incretin levels may prevent weight regain and T2D relapse. These data provide the basis for customizing BP limb length according to patient characteristics and desired metabolic effect. NEW & NOTEWORTHY Biliopancreatic limb length in gastric bypass modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. With a longer biliopancreatic limb, Roux limb hypertrophy, increased glucose utilization, reduced glucose absorption, and sustained high incretin levels may prevent weight regain and diabetes relapse.

Limb Lengthening Using the PRECICETM Nail System: Complications and Results

PubMed Central

Wiebking, Ulrich; Liodakis, Emmanouil; Kenawey, Mohamed; Krettek, Christian

2016-01-01

Background Three types of telescopic nails are mainly used for intramedullary limb lengthening nowadays. Despite some important advantages of this new technology (e.g. controlled distraction rate, not restricted availability, possibility to perform accordion maneuvers), few articles exist on clinical results and complications after lengthening with the PRECICETM nail (Ellipse, USA). Objectives The aim of the current study was to describe and analyze the complications associated with lengthening with the PRECICETM nail. Are the problems preventable when using the PRECICE, related to the distraction rate control, the lengthening goals and technique and handling? Methods We retrospectively reviewed the charts of 9 patients operated between 2012 and 2013 with a PRECICETM nail for a leg length discrepancy (LLD). The mean age of the patients was 32 years (range, 17 - 48 years). There were 5 femoral and 4 tibial procedures. The causes of LLD were posttraumatic (n = 5) and congenital (n = 4). The mean LLD was 36.4 ± 11.4 mm. The minimum follow-ups were 2 months (average, 5 months; range, 2 - 9 months). Results The mean distraction rate was 0.5 ± 0.1 mm/day. We observed in 7 patients differences in achieving the lengthening goals (average, 1.6 mm; range, -20.0 - 5.0 mm). Average lengthening was 34.7 ± 10.7 mm. All patients reached normal alignment and normal joint orientation. An unintentional loss of the achieved length during the consolidation phase was noticed in patients with delayed bone healing in two cases. In the first case (loss of 20mm distraction) the nail could be redistracted and the goal length was achieved. In the second case (loss of 10mm distraction) the nail broke shortly after the diagnosis and the nail was exchanged. Conclusions We report of loss of achieved length after lengthening with a telescopic nail. Weight bearing before complete consolidation of the regenerate might be a risk factor for that. Thorough examination of the limb length and careful evaluation of the radiographs are required in the follow-up period. The PRECICE nail system requires the same vigilance like the other intramedullary systems too. PMID:28144605

Locomotor variation and bending regimes of capuchin limb bones.

PubMed

Demes, Brigitte; Carlson, Kristian J

2009-08-01

Primates are very versatile in their modes of progression, yet laboratory studies typically capture only a small segment of this variation. In vivo bone strain studies in particular have been commonly constrained to linear locomotion on flat substrates, conveying the potentially biased impression of stereotypic long bone loading patterns. We here present substrate reaction forces (SRF) and limb postures for capuchin monkeys moving on a flat substrate ("terrestrial"), on an elevated pole ("arboreal"), and performing turns. The angle between the SRF vector and longitudinal axes of the forearm or leg is taken as a proxy for the bending moment experienced by these limb segments. In both frontal and sagittal planes, SRF vectors and distal limb segments are not aligned, but form discrepant angles; that is, forces act on lever arms and exert bending moments. The positions of the SRF vectors suggest bending around oblique axes of these limb segments. Overall, the leg is exposed to greater moments than the forearm. Simulated arboreal locomotion and turns introduce variation in the discrepancy angles, thus confirming that expanding the range of locomotor behaviors studied will reveal variation in long bone loading patterns that is likely characteristic of natural locomotor repertoires. "Arboreal" locomotion, even on a linear noncompliant branch, is characterized by greater variability of force directions and discrepancy angles than "terrestrial" locomotion (significant for the forearm only), partially confirming the notion that life in trees is associated with greater variation in long bone loading. Directional changes broaden the range of external bending moments even further.

Experience with latrogenic pediatric vascular injuries. Incidence, etiology, management, and results.

PubMed Central

Flanigan, D P; Keifer, T J; Schuler, J J; Ryan, T J; Castronuovo, J J

1983-01-01

During a 32-month period, 79 extremities in 76 children (age 1 day-13 years, mean = 31 months) were evaluated with regard to iatrogenic vascular injuries. Prospectively, 42 children were studied pre- and post-cardiac catheterization. Ten of these children sustained vascular injuries (incidence = 24%). Thirty-four additional children were referred because of 35 iatrogenic vascular injuries as a result of transfemoral cardiac catheterization (n = 20), umbilical artery catheterization (n = 10), or recent surgery (n = 5). All 45 injuries were evaluated by lower extremity segmental Doppler pressure measurements in addition to routine physical examination at the time of injury and at frequent follow-up. An ankle/brachial pressure index (ABI) less than 0.9 was considered abnormal. Selected children (ABI less than 0.9 for greater than 30 days) underwent orthoroentgenograms to assess limb growth. The average ABI immediately following injury was 0.34 +/- 0.33. Thirty-four injuries were treated nonoperatively. Twelve injuries were excluded from further study due to death (n = 7) or being lost to follow-yp (n = 5). A return of ABI to normal was seen from 1 day to 2 years in 93% of children treated with heparin (n = 14) compared to 63% of children who were simply observed (n = 8) (p less than 0.10). The initial severity of ischemia did not correlate with the subsequent rate of improvement. Only patients with absent femoral pulses were selected for operative intervention, which consisted of aortic thrombectomy (n = 2), femorofemoral bypass (n = 2), femoral artery patch angioplasty (n = 1), or femoral artery thrombectomy (n = 7) with no mortality. Nine patients had immediate return of a normal ABI after surgery. A delayed return of ABI to normal occurred in the other two. Nine per cent of surgically treated children and 23% of nonsurgically treated children developed leg length discrepancies (0.5-3.0 cm) as a result of ischemia lasting greater than 30 days. Overall, 91% of the children in this series eventually regained normal circulation following injury and no child lost a limb. This study indicates that iatrogenic pediatric vascular injuries are common and can result in significant limb growth impairment. Immediate operative intervention is highly successful when the injury is proximal to the common femoral artery bifurcation and avoids the prolonged ischemia seen with nonoperative therapy. For more distal occlusions, heparin therapy provides better results than simple observation. Although therapeutic intervention for these injuries is generally successful, a limb length discrepancy rate of 14% mandates that indications for invasive vascular monitoring and diagnostic procedures be strict. Images Fig. 2. Fig. 7. PMID:6625714

Functional specialisation of pelvic limb anatomy in horses (Equus caballus)

PubMed Central

Payne, RC; Hutchinson, JR; Robilliard, JJ; Smith, NC; Wilson, AM

2005-01-01

We provide quantitative anatomical data on the muscle–tendon units of the equine pelvic limb. Specifically, we recorded muscle mass, fascicle length, pennation angle, tendon mass and tendon rest length. Physiological cross sectional area was then determined and maximum isometric force estimated. There was proximal-to-distal reduction in muscle volume and fascicle length. Proximal limb tendons were few and, where present, were relatively short. By contrast, distal limb tendons were numerous and long in comparison to mean muscle fascicle length, increasing potential for elastic energy storage. When compared with published data on thoracic limb muscles, proximal pelvic limb muscles were larger in volume and had shorter fascicles. Distal limb muscle architecture was similar in thoracic and pelvic limbs with the exception of flexor digitorum lateralis (lateral head of the deep digital flexor), the architecture of which was similar to that of the pelvic and thoracic limb superficial digital flexors, suggesting a functional similarity. PMID:15960766

Distraction by a monotube fixator to achieve limb lengthening: predictive factors for tibia trauma

PubMed Central

2013-01-01

Background Management of post trauma tibia bone gap varied with orthopedic surgeons’ experience and tools available. Study aims to determine predictive factors for distraction by a monotube fixator (DMF) outcome in post tibia trauma limb length discrepancy. Methods A prospective descriptive cross sectional study of post traumatized tibia bone gap and limb length discrepancy patients at tertiary hospitals. Patient’s informed consent and institutional ethical committee approval were obtained. Bio-data, clinical and healing indexes were documented. DMF was applied for patient that met inclusion criteria. The Statistic tests used included the Chi-square, the Student’s two-tailed t test, and the Wilcox on rank-sum test when appropriate. Mantel-Haenszel Common Odds Ratio (OR) and 95% confidence intervals for poor outcome potential risk factors were recorded. Bivariate correlation and logistic regression were evaluated. Significance level was set at a p value <0.05. Results Thirty-six patients with mean age, 37.2 ± 10.3 year and male/female ratio of 1:1.25 had DMF applied. Motorcycle accident accounted for 50.0% of patients and diaphyseal segment was most commonly affected 25 (69.4%). The mean bone lengthened was 10.1 ± 4.0 cm (range: 5-21 cm) and mean duration of bone transport was 105.6 ± 38.2 days. The means of rate of distraction, healing index and percentage of lengthening were 0.99 ± 0.14 mm/day, 15.6 ± 4.3 days/cm and 38.0 ± 14.3 respectively. The mean follow up was 9.7 ±4.9 months (range: 2–17.0). Per operative complications varied and outcome was satisfactory in 30 (83.3%). Obesity (p <0.0001), multiple surgery (p = 0.012) and transfusion (p = 0.001) correlated to poor outcome. Percentage lengthening ≥ 50%, bone gap >10 cm, anemia, blood transfusion, general anesthesia administration, distraction rate >1 mm/day, osteomyelitis and prolong partial weight bearing were significant predictive factors for poor outcome in post traumatic tibia distraction. Conclusion Distraction by a monotube fixator appears effective in achieving correction >38.0% original tibia lengthening following traumatic bone gap. Predictive factors for poor outcome were useful for prognostication. PMID:23672599

Length asymmetry of the bovine digits.

PubMed

Muggli, E; Sauter-Louis, C; Braun, U; Nuss, K

2011-06-01

The lengths of the digital bones of the fore- and hind-limbs obtained post mortem from 40 cattle of different ages were measured using digital radiographs. The lengths of the individual digital bones and the overall length of the digit were determined using computer software. The lateral metacarpal/metatarsal condyle, and lateral P1 and P2 were significantly longer than their medial counterparts, whereas P3 of the medial digit was longer than its lateral partner. Measured from the cannon bone epiphysis to the tip of the pedal bone, the mean increased length of the lateral digit was 0.8 mm in the fore- and 1.5 mm in the hind-limb. When the lengths of the digital bones were summed, the mean length of the lateral digit was 1.8 mm longer in the fore-limb and 2.1 mm longer in the hind-limb. Based on these findings, it can be concluded that the lengths of the paired digits differ in cattle. The majority of cattle have longer lateral digits in the fore- and hind-limbs. This asymmetry might explain why the lateral hind-limb claws are predisposed to sole ulcers on hard surfaces. In the hind-limbs, the impact is transferred from the pelvis directly to the longer lateral digit. In the fore-limb claws, the tenomuscular attachment to the trunk may be involved in a more even weight distribution and in a shift of weight to the medial claw. Copyright © 2010 Elsevier Ltd. All rights reserved.

Inequality in leg length is important for the understanding of the pathophysiology of lumbar disc herniation

PubMed Central

Balik, Mehmet Sabri; Kanat, Ayhan; Erkut, Adem; Ozdemir, Bulent; Batcik, Osman Ersagun

2016-01-01

Objective: Inequality in leg length may lead to to abnormal transmission of load across the endplates and degeneration lumbar spine and the disc space. There has been no study focusing on lumbar disc herniation (LDH) and leg length discrepancy. This subject was investigated in this study. Materials and Methods: Consecutive adult patients with leg length discrepancy and low back pain (LBP) admitted to our department were respectivelly studied. Results: A total number of 39 subjects (31 women and eight men) with leg length discrepancy and LBP and 43 (25 females and 18 males) patients with LBP as a control group were tested. Occurrence of disc herniation is statistically different between patients with hip dysplasia and control groups (P < 0.05). Conclusion: The results of this study showed a statistically significant association between leg length discrepancy and occurrence of LDH. The changes of spine anatomy with leg length discrepancy in hip dysplastic patients are of importance in understanding the nature of LDH. PMID:27217654

Use of Paley Classification and SUPERankle Procedure in the Management of Fibular Hemimelia.

PubMed

Kulkarni, Ruta M; Arora, Nitish; Saxena, Sagar; Kulkarni, Sujay M; Saini, Yadwinder; Negandhi, Rajiv

2017-05-26

Fibular hemimelia is the most common deficiency involving the long bones. Paley classification is based on the ankle joint morphology, identifies the basic pathology, and helps in planning the surgical management. Reconstruction surgery encompasses foot deformity correction and limb length equalization. The SUPERankle procedure is a combination of bone and soft tissue procedures that stabilizes the foot and addresses all deformities. We retrospectively reviewed 29 consecutive patients (29 limb segments), surgically treated between December 2000 and December 2014. Among the 29 patients, 27 were treated with reconstructive procedures. Type 1 (8 patients) cases were treated with only limb lengthening, and correction of tibial deformities. Type 2 (7 patients) cases were treated by distal tibial medial hemiepiphysiodesis or supramalleolar varus osteotomy. In type 3 (10 patients) cases, the foot deformity was corrected using the SUPERankle procedure. Type 4 (2 patients) cases were treated with supramalleolar osteotomy along with posteromedial release and lateral column shortening. In a second stage, limb lengthening was performed, using the Ilizarov technique. In the remaining 2 patients (type 3A and type 3C), amputation was performed using Syme technique as a first choice of treatment. The results were evaluated using Association for the Study and Application of Methods of Ilizarov scoring. Excellent results were obtained in 15 of 27 (55%) patients. Six (22%) patients had good results, 4 (14.8%) had fair results, and 2 (7%) had poor results. Mean limb length discrepancy at initial presentation was 3.55 cm (range: 2 to 5.5 cm) which significantly improved to 1.01 cm (range: 0 to 3 cm) after treatment (P=0.015). Our results and a review of the literature clearly suggest that limb reconstruction according to Paley classification, is an excellent option in the management of fibular hemimelia. Our 2-staged procedure (SUPERankle procedure followed by limb lengthening) helps in reducing the complications of limb lengthening and incidence of ankle stiffness. Performing the first surgery at an earlier age (below 5 y) plays a significant role in preventing recurrent foot deformities. Level IV.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

[Tibiocalcaneal arthrodesis with retrograde nails. Description of a hindfoot procedure after massive talus destruction].

PubMed

Klos, K; Lange, A; Matziolis, G; Wagner, A

2013-05-01

Following loss of the talus, tibiocalcaneal fusion is often the only available means of obtaining weight-bearing ability in the lower limb. Length discrepancy may be managed with an allograft. This casuistic describes 6 patients with tibiocalcaneal fusion (mean age 64 years) who had received a structural femoral head allograft fusion for failed total ankle arthroplasty (3 cases), Charcot arthropathy (2 cases) and osteomyelitis (1 case). The mean follow-up was 33 months and all limbs could be salvaged. There were two cases of non-union (one with infection). The mean AOFAS score was 51 and the mean Mazur score was 37. In the SF-36 the mean PCS was 34.4 and the mean MCS was 48.4. It was shown that in the hindfoot, as at other sites, allografts may be used for the filling of major bone defects; however, the patient function will still be massively impaired. Therefore, the procedure should be confined to cases where less complex and less invasive techniques are unlikely to be of benefit.

A surgical protocol of ankle arthrodesis with combined Ilizarov's distraction-compression osteogenesis and locked nailing for osteomyelitis around the ankle joint.

PubMed

Chen, Chuan-Mu; Su, Alvin W; Chiu, Fang-Yao; Chen, Tain-Hsiung

2010-09-01

Managing refractory osteomyelitis around the ankle joint has been challenging. Destruction of both the ankle and the subtalar joints was common in cases of open fracture. For those who already had multiple surgeries, it would be tough to salvage the limb. Our goal was to set up a staged surgical protocol aiming in treating the aforementioned clinical issue. Twelve male patients underwent our protocol since year 2000. All patients presented refractory osteomyelitis, ankle and subtalar joint destruction, and poor soft tissue condition. All cases had internal fixation for open fractures followed by multiple debridement surgery before. The mean age was 50.8 years (range, 37-71 years), and the median follow-up time was 61 months (range, 48-96 months). The surgical protocol consisted of radical debridement, distraction osteogenesis for segmental bone transport, and tibia lengthening to avoid leg length discrepancy followed by intramedullary nailing for tibio-talo-calcaneal arthrodesis. The external fixation period averaged 24.7 weeks (range, 12-36 weeks). The mean duration to solid union of the arthrodesis and the bridging callus was 18.3 weeks (range, 16-20 weeks). Mild surgical site infection occurred in four cases but all subsided after removal of the nail and oral antibiotics use. At latest follow-up, all patients were infection free and could walk with plantigrade feet. The mean American Orthopaedic Foot and Ankle Society hindfoot score rising from 21.5 points (range 20-24 points) preoperatively to 65.5 points (range, 60-72). This study has shown our staged surgical protocol may be effective in solving complicated osteomyelitis around the ankle, although salvaging the limb with successful ankle arthrodesis and minimized limb length inequality, yet improving the patients' ambulation level.

Ipsilateral femur and tibia fractures in pediatric patients: A systematic review

PubMed Central

Anari, Jason B; Neuwirth, Alexander L; Horn, B David; Baldwin, Keith D

2017-01-01

AIM To better understand how pediatric floating knee injuries are managed after the wide spread use of new orthopaedic technology. METHODS We searched EMBASE, COCHRANE and MEDLINE computerized literature databases from the earliest date available in the databases to February 2017 using the following search term including variants and pleural counterparts: Pediatric floating knee. All studies were thoroughly reviewed by multiple authors. Reference lists from all articles were scrutinized to identify any additional studies of interest. A final database of individual patients was assembled from the literature. Univariate and multivariate statistical tests were applied to the assembled database to assess differences in outcomes. RESULTS The English language literature contains series with a total of 97 pediatric patients who sustained floating knee injuries. Patients averaged 9.3 years of age and were mostly male (73). Approximately 25% of the fractures were open injuries, more tibia (27) than femur (10). Over 75% of the fractures of both the tibia and the femur involved the diaphysis. More than half (52) of the patients were treated non-operatively for both fractures. As a sequela of the injury 32 (33%) patients were left with a limb length discrepancy, 24 (25%) patients had lengthening of the injured limb at follow up, while 8 (8%) had shortening of the affected limb. Infection developed in 9 patients and 3 had premature physeal closure. Younger patients were more likely to be treated non-operatively (P < 0.001) and patients treated with operative intervention had statistically significant shorter hospital length of stays (P = 0.001). CONCLUSION Given the predominance of non-operative management in published studies, the available literature is not clinically relevant since the popularization of internal fixation for pediatric long-bone fractures PMID:28875130

Ipsilateral femur and tibia fractures in pediatric patients: A systematic review.

PubMed

Anari, Jason B; Neuwirth, Alexander L; Horn, B David; Baldwin, Keith D

2017-08-18

To better understand how pediatric floating knee injuries are managed after the wide spread use of new orthopaedic technology. We searched EMBASE, COCHRANE and MEDLINE computerized literature databases from the earliest date available in the databases to February 2017 using the following search term including variants and pleural counterparts: Pediatric floating knee. All studies were thoroughly reviewed by multiple authors. Reference lists from all articles were scrutinized to identify any additional studies of interest. A final database of individual patients was assembled from the literature. Univariate and multivariate statistical tests were applied to the assembled database to assess differences in outcomes. The English language literature contains series with a total of 97 pediatric patients who sustained floating knee injuries. Patients averaged 9.3 years of age and were mostly male (73). Approximately 25% of the fractures were open injuries, more tibia (27) than femur (10). Over 75% of the fractures of both the tibia and the femur involved the diaphysis. More than half (52) of the patients were treated non-operatively for both fractures. As a sequela of the injury 32 (33%) patients were left with a limb length discrepancy, 24 (25%) patients had lengthening of the injured limb at follow up, while 8 (8%) had shortening of the affected limb. Infection developed in 9 patients and 3 had premature physeal closure. Younger patients were more likely to be treated non-operatively ( P < 0.001) and patients treated with operative intervention had statistically significant shorter hospital length of stays ( P = 0.001). Given the predominance of non-operative management in published studies, the available literature is not clinically relevant since the popularization of internal fixation for pediatric long-bone fractures.

Clinical Results and Complications of Lower Limb Lengthening for Fibular Hemimelia: A Report of Eight Cases.

PubMed

Mishima, Kenichi; Kitoh, Hiroshi; Iwata, Koji; Matsushita, Masaki; Nishida, Yoshihiro; Hattori, Tadashi; Ishiguro, Naoki

2016-05-01

Fibular hemimelia is a rare but the most common congenital long bone deficiency, encompassing a broad range of anomalies from isolated fibular hypoplasia up to substantial femoral and tibial shortening with ankle deformity and foot deficiency. Most cases of fibular hemimelia manifest clinically significant leg length discrepancy (LLD) with time that requires adequate correction by bone lengthening for stable walking. Bone lengthening procedures, especially those for pathological bones, are sometimes associated with severe complications, such as delayed consolidation, fractures, and deformities of the lengthened bones, leading to prolonged healing time and residual LLD at skeletal maturity. The purpose of this study was to review our clinical results of lower limb lengthening for fibular hemimelia.This study included 8 Japanese patients who diagnosed with fibular hemimelia from physical and radiological findings characteristic of fibular hemimelia and underwent single or staged femoral and/or tibial lengthening during growth or after skeletal maturity. LLD, state of the lengthened callus, and bone alignment were evaluated with full-length radiographs of the lower limb. Previous interventions, associated congenital anomalies, regenerate fractures were recorded with reference to medical charts and confirmed on appropriate radiographs. Successful lengthening was defined as the healing index <50 days/cm without regenerate fractures.A significant difference was observed in age at surgery between successful and unsuccessful lengthening. The incidence of regenerate fractures was significantly correlated with callus maturity before frame removal. LLD was corrected within 11 mm, whereas mechanical axis deviated laterally.Particular attention should be paid to the status of callus maturation and the mechanical axis deviation during the treatment period in fibular hemimelia.

The effects of prosthetic foot roll-over shape arc length on the gait of trans-tibial prosthesis users.

PubMed

Hansen, Andrew H; Meier, Margrit R; Sessoms, Pinata H; Childress, Dudley S

2006-12-01

The Shape&Roll prosthetic foot was used to examine the effect of roll-over shape arc length on the gait of 14 unilateral trans-tibial prosthesis users. Simple modifications to the prosthetic foot were used to alter the effective forefoot rocker length, leaving factors such as alignment, limb length, and heel and mid-foot characteristics unchanged. Shortening the roll-over shape arc length caused a significant reduction in the maximum external dorsiflexion moment on the prosthetic side at all walking speeds (p < 0.001 for main effect of arc length), due to a reduction in forefoot leverage (moment arm) about the ankle. Roll-over shape arc length significantly affected the initial loading on the sound limb at normal and fast speeds (p = 0.001 for the main effect of arc length), with participants experiencing larger first peaks of vertical ground reaction forces on their sound limbs when using the foot with the shortest effective forefoot rocker arc length. Additionally, the difference between step lengths on the sound and prosthetic limbs was larger with the shortest arc length condition, although this difference was not statistically significant (p = 0.06 for main effect). It appears that prosthesis users may experience a drop-off effect at the end of single limb stance on prosthetic feet with short roll-over shape arc lengths, leading to increased loading and/or a shortened step on the contralateral limb.

Scale effects between body size and limb design in quadrupedal mammals.

PubMed

Kilbourne, Brandon M; Hoffman, Louwrens C

2013-01-01

Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties--limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency--were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass(0.40)); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass(1.0)), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry.

Scale Effects between Body Size and Limb Design in Quadrupedal Mammals

PubMed Central

Kilbourne, Brandon M.; Hoffman, Louwrens C.

2013-01-01

Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties – limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency – were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass0.40); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass1.0), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry. PMID:24260117

Titanium-titanium modular neck for primary THA. Result of a prospective series of 170 cemented THA with a minimum follow-up of 5 years.

PubMed

Ollivier, M; Parratte, S; Galland, A; Lunebourg, A; Flecher, X; Argenson, J-N

2015-04-01

Although they have been in use since the end of the 1980s, modular titanium neck components are associated with a risk of wear or fracture, and their safety has recently become a subject of debate and has never been evaluated in a consecutive series of patients. The goal of this study was to evaluate: revision-free survival of these implants after a minimum follow-up of 5 years; clinical and radiographic results; and the potential complications associated with the use of modular titanium neck components. The use of titanium modular neck on cemented titanium THA is safe at a minimum follow-up of 5 years. Between January 2006 and December 2008, we prospectively followed 170 patients (170 hips) who underwent primary anatomical THA with a modular cemented titanium stem design implant. The indications were unilateral THA for primary (n=160) or secondary (n=10) hip osteoarthritis (aseptic osteonecrosis of the femoral head or hip dysplasia). Mean age of patients was 75.4±5.8 years old (52-85), and mean BMI was 26.1±4.5 kg/m(2) (16.6-42.1). Patients were operated on by a modified Watson-Jones anterolateral approach based on preoperative 2D planning. All patients underwent annual clinical and radiological follow-up by an independent observer. At a mean follow-up of 71±8 months (60-84), 5 patients died and 7 were lost to follow-up. There was no revision of THA after a maximum follow-up of 84 months. The Harris score improved significantly from 50.4±11.3 (0-76) preoperatively to 84.5±15.2 (14-100) at the final follow-up. There was no difference in postoperative femoral offset or the position of the center of rotation compared to the opposite side. On the other hand, the neck-shaft angle (NSA) and limb length were corrected (2±5° [-11 to +14°] and 2.16±3.6 mm [-7.4 to +12.7 mm]) respectively. Fifteen patients (9%) had limb length discrepancies of more than 5 mm and 4 patients (2%) of more than 10 mm. There were no complications due to the modular implant design. Our study suggests that the use of cemented titanium implants with a modular titanium stem is safe at a follow-up of 5 years. The modular design does not prevent limb length discrepancies but restores femoral offset. IV: prospective, non-comparative study. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Achondroplasia: Really rhizomelic?

PubMed

Shelmerdine, Susan Cheng; Brittain, Helen; Arthurs, Owen J; Calder, Alistair D

2016-08-01

Achondroplasia is the most common form of short limb dwarfism in humans. The shortening of the limb lengths in achondroplasia is widely described as "rhizomelic." While this appearance may be convincing clinically, the description is not necessarily true or helpful radiologically. The aims of this study, were therefore, to determine whether rhizomelic shortening is a true feature of achondroplasia at diagnosis in infancy. Humeral, radial, femoral, and tibial diaphyseal lengths were recorded by two independent observers from 22 skeletal surveys of infants with achondroplasia and compared with 150 normal age-matched control subjects. Upper and lower limb bone length ratios (radial/humeral and tibial/femoral lengths, respectively) in both groups were compared using an unpaired t-test. Mean upper limb length ratios were statistically higher within the achondroplasia group at 0.87 ± 0.04 (n = 22, mean age 70 ± 94 days) compared to normal controls at 0.79 ± 0.02 (n = 150, mean age 113 days ± 88 days; P < 0.0001). Lower limb length ratios were not significantly different between groups (0.84 ± 0.04 vs. 0.83 ± 0.02, P = 0.46). There was good inter-observer agreement of limb length measurements, with an average measurement difference of 0.1 ± 1.4 mm. In conclusion, infants with achondroplasia demonstrate statistically significant rhizomelic shortening within the upper limbs, but not lower limbs at diagnosis, compared to normal controls. The term "rhizomelic shortening" in relation to achondroplasia should be reserved when describing upper limb proportions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Comparison of transtibial amputee and non-amputee biomechanics during a common turning task.

PubMed

Segal, Ava D; Orendurff, Michael S; Czerniecki, Joseph M; Schoen, Jason; Klute, Glenn K

2011-01-01

The biomechanics of amputee turning gait has been minimally studied, in spite of its integral relationship with the more complex gait required for household or community ambulation. This study compares the biomechanics of unilateral transtibial amputees and non-amputees completing a common turning task. Full body gait analysis was completed for subjects walking at comparable self-selected speeds around a 1m radius circular path. Peak internal and external rotation moments of the hip, knee and ankle, mediolateral ground reaction impulse (ML GRI), peak effective limb length, and stride length were compared across conditions (non-amputee, amputee prosthetic limb, amputee sound limb). Amputees showed decreased internal rotation moments at the prosthetic limb hip and knee compared to non-amputees, perhaps as a protective mechanism to minimize stress on the residual limb. There was also an increase in amputee sound limb hip external rotation moment in early stance compared to non-amputees, which may be a compensation for the decrease in prosthetic limb internal rotation moment during late stance of the prior step. ML GRI was decreased for the amputee inside limb compared to non-amputee, possibly to minimize the body's acceleration in the direction of the turn. Amputees also exhibited a shorter inside limb stride length compared to non-amputees. Both decreased ML GRI and stride length indicate a COM that is more centered over the base of support, which may minimize the risk of falling. Finally, a longer effective limb length was found for the amputee inside limb turning, possibly due to excessive trunk shift. Published by Elsevier B.V.

Outcome of limb reconstruction system in open tibial diaphyseal fractures.

PubMed

Ajmera, Anand; Verma, Ankit; Agrawal, Mukul; Jain, Saurabh; Mukherjee, Arunangshu

2015-01-01

Management of open tibial diaphyseal fractures with bone loss is a matter of debate. The treatment options range from external fixators, nailing, ring fixators or grafting with or without plastic reconstruction. All the procedures have their own set of complications, like acute docking problems, shortening, difficulty in soft tissue management, chronic infection, increased morbidity, multiple surgeries, longer hospital stay, mal union, nonunion and higher patient dissatisfaction. We evaluated the outcome of the limb reconstruction system (LRS) in the treatment of open fractures of tibial diaphysis with bone loss as a definative mode of treatment to achieve union, as well as limb lengthening, simultaneously. Thirty open fractures of tibial diaphysis with bone loss of at least 4 cm or more with a mean age 32.5 years were treated by using the LRS after debridement. Distraction osteogenesis at rate of 1 mm/day was done away from the fracture site to maintain the limb length. On the approximation of fracture ends, the dynamized LRS was left for further 15-20 weeks and patient was mobilized with weight bearing to achieve union. Functional assessment was done by Association for the Study and Application of the Methods of Illizarov (ASAMI) criteria. Mean followup period was 15 months. The mean bone loss was 5.5 cm (range 4-9 cm). The mean duration of bone transport was 13 weeks (range 8-30 weeks) with a mean time for LRS in place was 44 weeks (range 24-51 weeks). The mean implant index was 56.4 days/cm. Mean union time was 52 weeks (range 31-60 weeks) with mean union index of 74.5 days/cm. Bony results as per the ASAMI scoring were excellent in 76% (19/25), good in 12% (3/25) and fair in 4% (1/25) with union in all except 2 patients, which showed poor results (8%) with only 2 patients having leg length discrepancy more than 2.5 cm. Functional results were excellent in 84% (21/25), good in 8% (2/25), fair in 8% (2/25). Pin tract infection was seen in 5 cases, out of which 4 being superficial, which healed to dressings and antibiotics. One patient had a deep infection which required frame removal. Limb reconstruction system proved to be an effective modality of treatment in cases of open fractures of the tibia with bone loss as definite modality of treatment for damage control as well as for achieving union and lengthening, simultaneously, with the advantage of early union with attainment of limb length, simple surgical technique, minimal invasive, high patient compliance, easy wound management, lesser hospitalization and the lower rate of complications like infection, deformity or shortening.

Body proportions in ancient Andeans from high and low altitudes.

PubMed

Weinstein, Karen J

2005-11-01

Living human populations from high altitudes in the Andes exhibit relatively short limbs compared with neighboring groups from lower elevations as adaptations to cold climates characteristic of high-altitude environments. This study compares relative limb lengths and proportions in pre-Contact human skeletons from different altitudes to test whether ecogeographic variation also existed in Andean prehistory. Maximum lengths of the humerus, radius, femur, and tibia, and femoral head breadth are measured in sex-specific groups of adult human skeletons (N = 346) from the central (n = 80) and the south-central (n = 123) Andean coasts, the Atacama Desert at 2,500 m (n = 102), and the southern Peruvian highlands at 2,000-3,800 m (n = 41). To test whether limb lengths vary with altitude, comparisons are made of intralimb proportions, limb lengths against body mass estimates derived from published equations, limb lengths against the geometric mean of all measurements, and principal component analysis. Intralimb proportions do not statistically differ between coastal groups and those from the Atacama Desert, whereas intralimb proportions are significantly shorter in the Peruvian highland sample. Overall body size and limb lengths relative to body size vary along an altitudinal gradient, with larger individuals from coastal environments and smaller individuals with relatively longer limbs for their size from higher elevations. Ecogeographic variation in relation to climate explains the variation in intralimb proportions, and dietary variation may explain the altitudinal cline in body size and limb lengths relative to body size. The potential effects of gene flow on variation in body proportions in Andean prehistory are also explored. Copyright 2005 Wiley-Liss, Inc

The effects of body proportions on thermoregulation: an experimental assessment of Allen's rule.

PubMed

Tilkens, Michael J; Wall-Scheffler, Cara; Weaver, Timothy D; Steudel-Numbers, Karen

2007-09-01

Numerous studies have discussed the influence of thermoregulation on hominin body shape concluding, in accordance with Allen's rule, that the presence of relatively short limbs on both extant as well as extinct hominin populations offers an advantage for survival in cold climates by reducing the limb's surface area to volume ratio. Moreover, it has been suggested that shortening the distal limb segment compared to the proximal limb segment may play a larger role in thermoregulation due to a greater relative surface area of the shank. If longer limbs result in greater heat dissipation, we should see higher resting metabolic rates (RMR) in longer-limbed individuals when temperature conditions fall, since the resting rate will need to replace the lost heat. We collected resting oxygen consumption on volunteer human subjects to assess the correlation between RMR and lower limb length in human subjects, as well as to reexamine the prediction that shortening the distal segment would have a larger effect on heat loss and, thus, RMR than the shortening of the proximal segment. Total lower limb length exhibits a statistically significant relationship with resting metabolic rate (p<0.001; R(2)=0.794). While this supports the hypothesis that as limb length increases, resting metabolic rate increases, it also appears that thigh length, rather than the length of the shank, drives this relationship. The results of the present study confirm the widely-held expectation of Allen's rule, that short limbs reduce the metabolic cost of maintaining body temperature, while long limbs result in greater heat dissipation regardless of the effect of mass. The present results suggest that the shorter limbs of Neandertals, despite being energetically disadvantageous while walking, would indeed have been advantageous for thermoregulation.

Axial deformity correction in children via distraction osteogenesis.

PubMed

Antoci, Valentin; Ono, Craig M; Antoci, Valentin; Raney, Ellen M

2006-08-01

We performed a retrospective analysis of the results of 62 tibial and 54 femoral lengthenings in 88 consecutive patients. The patients mean age was 13.5 years and mean follow-up was four years. There was a significant difference between metaphyseal (27+/-1.2 days/cm) and diaphyseal (39.4+/-1.7 days/cm), tibial (34+/-1.7 days/cm) and femoral (31+/-1.4 days/cm) lengthening (P<0.05), but no significant difference among the lengthening indexes when treating one-, two-, or three-dimensional deformities, congenital (34+/-2.4 days/cm) and acquired (32+/-1.0 days/cm) limb length discrepancy (LLD) (P>0.05). The lengthening index was 33+/-1.1 days/cm, distraction regenerate length 6+/-0.4 cm, and lengthening percentage 21+/-2.1. The scatter plots of new regenerate length against time and the scatter plots of neurological complication, residual deformities, broken pins, joint contractures, and hypertension rate against lengthening percentage showed a positive linear relationship (r=0.8). We found the correlations between quantitative and qualitative parameters that should help to predict the treatment outcomes. Lengthening index depends on the amount of length gained. Higher length of new bone regenerate leads to a decrease in lengthening index. Expected gain in bone length can aid in estimating the duration of treatment. The lengthening percentage correlates very well with the complication rate and can be used to predict the complication rate.

Effect of unilateral knee extensor fatigue on force and balance of the contralateral limb.

PubMed

Arora, Shruti; Budden, Shawn; Byrne, Jeannette M; Behm, David G

2015-10-01

Fatigue in one limb can decrease force production in the homologous muscle as well as other muscles of the non-fatigued limb affecting balance. The objective of the study was to examine the effect of unilateral knee extensor fatigue on the non-fatigued limb's standing balance, muscle force and activation. Sixteen healthy male subjects performed pre-fatigue balance trials, warm-up exercises, maximum voluntary isometric contractions, a knee extensors fatigue protocol, and post-fatigue balance trials. The fatigue protocol consisted of sets of 15 consecutive isometric contractions of 16 s each with 4 s recovery between repetitions, which were performed at 30% peak force for the dominant knee extensor muscles. Additional sets of contractions continued until a 50% decrease in MVIC knee extensor force was observed. Pre- and post-fatigue balance assessment consisted of transition from double to single leg standing and also single leg standing trials, which were performed bilaterally and in randomized order. The peak force and F100 were significantly decreased by 44.8% (ES = 2.54) and 39.9% (ES = 0.59), respectively, for the fatigued limb post-fatigue. There were no significant changes in the non-fatigued limb's muscle force, activation, muscle onset timing or postural stability parameters. While the lack of change in non-fatigued limb force production is in agreement with some of the previous literature in this area, the lack of effect on postural measures directly contradicts earlier work. It is hypothesized that discrepancies in the duration and the intensity of the fatigue protocol may have accounted for this discrepancy.

Reconstruction with distraction osteogenesis for juxta-articular nonunions with bone loss.

PubMed

Kabata, Tamon; Tsuchiya, Hiroyuki; Sakurakichi, Keisuke; Yamashiro, Teruhisa; Watanabe, Koji; Tomita, Kasuro

2005-06-01

Nonunions of a juxta-articular lesion with bone loss, which represent a challenging therapeutic problem, were treated using external fixation and distraction osteogenesis. Seven juxta-articular nonunions (five septic and two aseptic) were treated. The location of the nonunion was the distal femur in four patients, the proximal tibia in one patient, and the distal tibia in two patients. All of them were located within 5 cm from the affected joints. Preoperative limb shortening was present in six cases, averaging 2.9 cm (range, 1-7 cm). The reconstructive procedure consisted of refreshment of the nonunion site, deformity correction, stabilization by external fixation, and lengthening to eliminate leg length discrepancy or to fill the defect. Shortening-distraction was applied to six patients and bone transport to one patient for reconstruction. Intramedullary nailing to reduce the duration of external fixation was simultaneously performed in two cases. All the patients had at least 1 year of follow-up evaluation. Osseous union without angular deformity or leg length discrepancy greater than 1 cm was achieved in all patients. The mean amount of lengthening was 5.8 cm (range, 2.2-10.0 cm). The mean external fixation period was 219 days (range, 98-317 days), and the mean external fixation index was 34.4 days/cm (range, 24.5-47.6 days/cm). All patients reported excellent pain reduction. There were no recurrences of infection in five patients with prior history of osteomyelitis. The functional results were categorized as excellent in two, good in three, and fair in two. Despite the length of postoperative external fixation, distraction osteogenesis can be a valuable alternative for the treatment of juxta-articular nonunions.

Developmental origin of limb size variation in lizards.

PubMed

Andrews, Robin M; Skewes, Sable A

2017-05-01

In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

Tibial Lengthening: Extraarticular Calcaneotibial Screw to Prevent Ankle Equinus

PubMed Central

Belthur, Mohan V.; Paley, Dror; Jindal, Gaurav; Burghardt, Rolf D.; Specht, Stacy C.

2008-01-01

Between 2003 and 2006, we used an extraarticular, cannulated, fully threaded posterior calcaneotibial screw to prevent equinus contracture in 10 patients (four male and six female patients, 14 limbs) undergoing tibial lengthening with the intramedullary skeletal kinetic distractor. Diagnoses were fibular hemimelia (two), mesomelic dwarfism (two), posteromedial bow (one), hemihypertrophy (one), poliomyelitis (one), achondroplasia (one), posttraumatic limb-length discrepancy (one), and hypochondroplasia (one). Average age was 24.5 years (range, 15–54 years). The screw (length, typically 125 mm; diameter, 7 mm) was inserted with the ankle in 10° dorsiflexion. Gastrocnemius soleus recession was performed in two patients to achieve 10° dorsiflexion. Average lengthening was 4.9 cm (range, 3–7 cm). Screws were removed after a mean 3.3 months (range, 2–6 months). Preoperative ankle range of motion was regained within 6 months of screw removal. No neurovascular complications were encountered, and no patients experienced equinus contracture. We also conducted a cadaveric study in which one surgeon inserted screws in eight cadaveric legs under image intensifier control. The flexor hallucis longus muscle belly was the closest anatomic structure noted during dissection. The screw should be inserted obliquely from upper lateral edge of the calcaneus and aimed lateral in the tibia to avoid the flexor hallucis longus muscle. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18800215

A genome-wide association study of limb bone length using a Large White × Minzhu intercross population.

PubMed

Zhang, Long-Chao; Li, Na; Liu, Xin; Liang, Jing; Yan, Hua; Zhao, Ke-Bin; Pu, Lei; Shi, Hui-Bi; Zhang, Yue-Bo; Wang, Li-Gang; Wang, Li-Xian

2014-11-04

In pig, limb bone length influences ham yield and body height to a great extent and has important economic implications for pig industry. In this study, an intercross population was constructed between the indigenous Chinese Minzhu pig breed and the western commercial Large White pig breed to examine the genetic basis for variation in limb bone length. The aim of this study was to detect potential genetic variants associated with porcine limb bone length. A total of 571 F2 individuals from a Large White and Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip, and phenotyped for femur length (FL), humerus length (HL), hipbone length (HIPL), scapula length (SL), tibia length (TL), and ulna length (UL). A genome-wide association study was performed by applying the previously reported approach of genome-wide rapid association using mixed model and regression. Statistical significance of the associations was based on Bonferroni-corrected P-values. A total of 39 significant SNPs were mapped to a 11.93 Mb long region on pig chromosome 7 (SSC7). Linkage analysis of these significant SNPs revealed three haplotype blocks of 495 kb, 376 kb and 492 kb, respectively, in the 11.93 Mb region. Annotation based on the pig reference genome identified 15 genes that were located near or contained the significant SNPs in these linkage disequilibrium intervals. Conditioned analysis revealed that four SNPs, one on SSC2 and three on SSC4, showed significant associations with SL and HL, respectively. Analysis of the 15 annotated genes that were identified in these three haplotype blocks indicated that HMGA1 and PPARD, which are expressed in limbs and influence chondrocyte cell growth and differentiation, could be considered as relevant biological candidates for limb bone length in pig, with potential applications in breeding programs. Our results may also be useful for the study of the mechanisms that underlie human limb length and body height.

An approach to scoring cursorial limb proportions in carnivorous dinosaurs and an attempt to account for allometry.

PubMed

Persons, W Scott; Currie, Philip J

2016-01-27

From an initial dataset of 53 theropod species, the general relationship between theropod lower-leg length and body mass is identified. After factoring out this allometric relationship, theropod hindlimb proportions are assessed irrespective of body mass. Cursorial-limb-proportion (CLP) scores derived for each of the considered theropod taxa offer a measure of the extent to which a particular species deviates in favour of higher or lower running speeds. Within the same theropod species, these CLP scores are found to be consistent across multiple adult specimens and across disparate ontogenetic stages. Early theropods are found to have low CLP scores, while the coelurosaurian tyrannosauroids and compsognathids are found to have high CLP scores. Among deinonychosaurs, troodontids have consistently high CLP scores, while many dromaeosaur taxa, including Velociraptor and Deinonychus, have low CLP scores. This indicates that dromaeosaurs were not, overall, a particularly cursorily adapted group. Comparisons between the CLP scores of Tyrannosaurus and specimens referred to the controversial genus Nanotyrannus indicate a strong discrepancy in cursorial adaptations, which supports the legitimacy of Nanotyrannus and the previous suggestions of ecological partitioning between Nanotyrannus and the contemporaneous Tyrannosaurus.

An approach to scoring cursorial limb proportions in carnivorous dinosaurs and an attempt to account for allometry

PubMed Central

Persons IV, W. Scott; Currie, Philip J.

2016-01-01

From an initial dataset of 53 theropod species, the general relationship between theropod lower-leg length and body mass is identified. After factoring out this allometric relationship, theropod hindlimb proportions are assessed irrespective of body mass. Cursorial-limb-proportion (CLP) scores derived for each of the considered theropod taxa offer a measure of the extent to which a particular species deviates in favour of higher or lower running speeds. Within the same theropod species, these CLP scores are found to be consistent across multiple adult specimens and across disparate ontogenetic stages. Early theropods are found to have low CLP scores, while the coelurosaurian tyrannosauroids and compsognathids are found to have high CLP scores. Among deinonychosaurs, troodontids have consistently high CLP scores, while many dromaeosaur taxa, including Velociraptor and Deinonychus, have low CLP scores. This indicates that dromaeosaurs were not, overall, a particularly cursorily adapted group. Comparisons between the CLP scores of Tyrannosaurus and specimens referred to the controversial genus Nanotyrannus indicate a strong discrepancy in cursorial adaptations, which supports the legitimacy of Nanotyrannus and the previous suggestions of ecological partitioning between Nanotyrannus and the contemporaneous Tyrannosaurus. PMID:26813782

Effects of varying inter-limb spacing to limb length ratio in metachronal swimming

NASA Astrophysics Data System (ADS)

Lai, Hong Kuan; Merkel, Rachael; Santhanakrishnan, Arvind

2016-11-01

Crustaceans such as shrimp, krill and crayfish swim by rhythmic paddling of four to five pairs of closely spaced limbs. Each pair is phase-shifted in time relative to the neighboring pair, resulting in a metachronal wave that travels in the direction of animal motion. The broad goal of this study is to investigate how the mechanical design of the swimming limbs affect scalability of metachronal swimming in terms of limb-based Reynolds number (Re). A scaled robotic model of metachronal paddling was developed, consisting of four pairs of hinged acrylic plates actuated using stepper motors that were immersed in a rectangular tank containing water-glycerin fluid medium. 2D PIV measurements show that the propulsive jets transition from being primarily horizontal (thrust-producing direction) at Re of order 10 to angled vertically at Re of order 100. The ratio of inter-limb spacing to limb length among metachronal swimming organisms ranges between 0.2 to 0.65. 2D PIV will be used to examine the jets generated between adjacent limbs for varying inter-limb spacing to limb length ratios. The effect of increasing this ratio to beyond the biologically observed range will be discussed.

Relationships between neonatal weight, limb lengths, skinfold thicknesses, body breadths and circumferences in an Australian cohort.

PubMed

Pomeroy, Emma; Stock, Jay T; Cole, Tim J; O'Callaghan, Michael; Wells, Jonathan C K

2014-01-01

Low birth weight has been consistently associated with adult chronic disease risk. The thrifty phenotype hypothesis assumes that reduced fetal growth impacts some organs more than others. However, it remains unclear how birth weight relates to different body components, such as circumferences, adiposity, body segment lengths and limb proportions. We hypothesized that these components vary in their relationship to birth weight. We analysed the relationship between birth weight and detailed anthropometry in 1270 singleton live-born neonates (668 male) from the Mater-University of Queensland Study of Pregnancy (Brisbane, Australia). We tested adjusted anthropometry for correlations with birth weight. We then performed stepwise multiple regression on birth weight of: body lengths, breadths and circumferences; relative limb to neck-rump proportions; or skinfold thicknesses. All analyses were adjusted for sex and gestational age, and used logged data. Circumferences, especially chest, were most strongly related to birth weight, while segment lengths (neck-rump, thigh, upper arm, and especially lower arm and lower leg) were relatively weakly related to birth weight, and limb lengths relative to neck-rump length showed no relationship. Skinfolds accounted for 36% of birth weight variance, but adjusting for size (neck-rump, thigh and upper arm lengths, and head circumference), this decreased to 10%. There was no evidence that heavier babies had proportionally thicker skinfolds. Neonatal body measurements vary in their association with birth weight: head and chest circumferences showed the strongest associations while limb segment lengths did not relate strongly to birth weight. After adjusting for body size, subcutaneous fatness accounted for a smaller proportion of birth weight variance than previously reported. While heavier babies had absolutely thicker skinfolds, this was proportional to their size. Relative limb to trunk length was unrelated to birth weight, suggesting that limb proportions at birth do not index factors relevant to prenatal life.

Relationships between Neonatal Weight, Limb Lengths, Skinfold Thicknesses, Body Breadths and Circumferences in an Australian Cohort

PubMed Central

Pomeroy, Emma; Stock, Jay T.; Cole, Tim J.; O'Callaghan, Michael; Wells, Jonathan C. K.

2014-01-01

Background Low birth weight has been consistently associated with adult chronic disease risk. The thrifty phenotype hypothesis assumes that reduced fetal growth impacts some organs more than others. However, it remains unclear how birth weight relates to different body components, such as circumferences, adiposity, body segment lengths and limb proportions. We hypothesized that these components vary in their relationship to birth weight. Methods We analysed the relationship between birth weight and detailed anthropometry in 1270 singleton live-born neonates (668 male) from the Mater-University of Queensland Study of Pregnancy (Brisbane, Australia). We tested adjusted anthropometry for correlations with birth weight. We then performed stepwise multiple regression on birth weight of: body lengths, breadths and circumferences; relative limb to neck-rump proportions; or skinfold thicknesses. All analyses were adjusted for sex and gestational age, and used logged data. Results Circumferences, especially chest, were most strongly related to birth weight, while segment lengths (neck-rump, thigh, upper arm, and especially lower arm and lower leg) were relatively weakly related to birth weight, and limb lengths relative to neck-rump length showed no relationship. Skinfolds accounted for 36% of birth weight variance, but adjusting for size (neck-rump, thigh and upper arm lengths, and head circumference), this decreased to 10%. There was no evidence that heavier babies had proportionally thicker skinfolds. Conclusions Neonatal body measurements vary in their association with birth weight: head and chest circumferences showed the strongest associations while limb segment lengths did not relate strongly to birth weight. After adjusting for body size, subcutaneous fatness accounted for a smaller proportion of birth weight variance than previously reported. While heavier babies had absolutely thicker skinfolds, this was proportional to their size. Relative limb to trunk length was unrelated to birth weight, suggesting that limb proportions at birth do not index factors relevant to prenatal life. PMID:25162658

Melorheostosis of the hand affecting the c6 sclerotome and presenting with carpal tunnel syndrome

PubMed Central

Abdullah, Shalimar; Nor, Noreen Fazlina Mat; Haflah, Nor Hazla Mohamed

2014-01-01

Melorheostosis is a rare, progressive bone disease accompanied by hyperostosis and soft tissue fibrosis. While affected adults present with contracture and pain, children present with limb length discrepancy and deformity. We report the case of a 20-year-old woman with melorheostosis since childhood who presented with right hand deformity and numbness. Radiographs showed not only a combination of dense sclerosis and opacities, but also the classic ‘flowing candle wax’ appearance. Radiography can be used to identify melorheostosis, thus preventing unnecessary bone biopsies. Carpal tunnel release revealed the presence of a thickened flexor retinaculum and a degenerated median nerve distal to the retinaculum, but did not show hyperostosis. This case highlights the role of nerve decompression in melorheostosis and the importance of early identification of the disease to prevent unnecessary bone biopsies. PMID:24763843

Melorheostosis of the hand affecting the c6 sclerotome and presenting with carpal tunnel syndrome.

PubMed

Abdullah, Shalimar; Mat Nor, Noreen Fazlina; Mohamed Haflah, Nor Hazla

2014-04-01

Melorheostosis is a rare, progressive bone disease accompanied by hyperostosis and soft tissue fibrosis. While affected adults present with contracture and pain, children present with limb length discrepancy and deformity. We report the case of a 20-year-old woman with melorheostosis since childhood who presented with right hand deformity and numbness. Radiographs showed not only a combination of dense sclerosis and opacities, but also the classic 'flowing candle wax' appearance. Radiography can be used to identify melorheostosis, thus preventing unnecessary bone biopsies. Carpal tunnel release revealed the presence of a thickened flexor retinaculum and a degenerated median nerve distal to the retinaculum, but did not show hyperostosis. This case highlights the role of nerve decompression in melorheostosis and the importance of early identification of the disease to prevent unnecessary bone biopsies.

Energetic benefits and adaptations in mammalian limbs: Scale effects and selective pressures.

PubMed

Kilbourne, Brandon M; Hoffman, Louwrens C

2015-06-01

Differences in limb size and shape are fundamental to mammalian morphological diversity; however, their relevance to locomotor costs has long been subject to debate. In particular, it remains unknown if scale effects in whole limb morphology could partially underlie decreasing mass-specific locomotor costs with increasing limb length. Whole fore- and hindlimb inertial properties reflecting limb size and shape-moment of inertia (MOI), mass, mass distribution, and natural frequency-were regressed against limb length for 44 species of quadrupedal mammals. Limb mass, MOI, and center of mass position are negatively allometric, having a strong potential for lowering mass-specific locomotor costs in large terrestrial mammals. Negative allometry of limb MOI results in a 40% reduction in MOI relative to isometry's prediction for our largest sampled taxa. However, fitting regression residuals to adaptive diversification models reveals that codiversification of limb mass, limb length, and body mass likely results from selection for differing locomotor modes of running, climbing, digging, and swimming. The observed allometric scaling does not result from selection for energetically beneficial whole limb morphology with increasing size. Instead, our data suggest that it is a consequence of differing morphological adaptations and body size distributions among quadrupedal mammals, highlighting the role of differing limb functions in mammalian evolution. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Allometric associations between body size, shape, and 100-m butterfly speed performance.

PubMed

Sammoud, Senda; Nevill, Alan M; Negra, Yassine; Bouguezzi, Raja; Chaabene, Helmi; Hachana, Younés

2018-05-01

This study aimed to estimate the optimal body size, limb-segment length, and girth or breadth ratios associated with 100-m butterfly speed performance in swimmers. One-hundred-sixty-seven swimmers as subjects (male: N.=103; female: N.=64). Anthropometric measurements comprised height, body-mass, skinfolds, arm-span, upper-limb-length, upper-arm, forearm, hand-lengths, lower-limb-length, thigh-length, leg-length, foot-length, arm-relaxed-girth, forearm-girth, wrist-girth, thigh-girth, calf-girth, ankle-girth, biacromial and biiliocristal-breadths. To estimate the optimal body size and body composition components associated with 100-m butterfly speed performance, we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. Fat-mass was the singularly most important whole-body characteristic. Height and body-mass did not contribute to the model. The allometric model identified that having greater limb segment length-ratio (arm-ratio = [arm-span]/[forearm]) and limb girth-ratio (girth-ratio = [calf-girth]/[ankle-girth]) were key to butterfly speed performance. A greater arm-span to forearm-length ratio and a greater calf to ankle-girth-ratio suggest that a combination of larger arm-span and shorter forearm-length and the combination of larger calves and smaller ankles-girth may benefit butterfly swim speed performance. In addition having greater biacromial and biliocristal breadths is also a major advantage in butterfly swimming speed performance. Finally, the estimation of these ratios was made possible by adopting a multiplicative allometric model that was able to confirm, theoretically, that swim speeds are nearly independent of total body size. The 100-m butterfly speed performance was strongly negatively associated with fat mass and positively associated with the segment length ratio (arm-span/forearm-length) and girth ratio (calf-girth)/(ankle-girth), having controlled for the developmental changes in age.

Effects of lower limb length and body proportions on the energy cost of overground walking in older persons.

PubMed

Vannetti, Federica; Pasquini, Guido; Vitiello, Nicola; Molino-Lova, Raffaele

2014-01-01

Although walking has been extensively investigated in its biomechanical and physiological aspects, little is known on whether lower limb length and body proportions affect the energy cost of overground walking in older persons. We enrolled 50 men and 12 women aged 65 years and over, mean 69.1 ± SD 5.4, who at the end of their cardiac rehabilitation program performed the six-minute walk test while wearing a portable device for direct calorimetry and who walked a distance comparable to that of nondisabled community-dwelling older persons. In the multivariable regression model (F = 12.75, P < 0.001, adjusted R(2) = 0.278) the energy cost of overground walking, expressed as the net energy expenditure, in kg(-1) sec(-1), needed to provide own body mass with 1 joule kinetic energy, was inversely related to lower limb length and directly related to lower limb length to height ratio (β ± SE(β) = -3.72 × 10(-3) ± 0.74 × 10(-3), P < 0.001, and 6.61 × 10(-3) ± 2.14 × 10(-3), P = 0.003, resp.). Ancillary analyses also showed that, altogether, 1 cm increase in lower limb length reduced the energy cost of overground walking by 2.57% (95%CI 2.35-2.79). Lower limb length and body proportions actually affect the energy cost of overground walking in older persons.

Relating ranging ecology, limb length, and locomotor economy in terrestrial animals.

PubMed

Pontzer, Herman

2012-03-07

Ecomorphological analyses have identified a number of important evolutionary trends in vertebrate limb design, but the relationships between daily travel distance, locomotor ecology, and limb length in terrestrial animals remain poorly understood. In this paper I model the net rate of energy intake as a function of foraging efficiency, and thus of locomotor economy; improved economy leads to greater net energy intake. However, the relationship between locomotor economy and net intake is highly dependent on foraging efficiency; only species with low foraging efficiencies experience strong selection pressure for improved locomotor economy and increased limb length. Examining 237 terrestrial species, I find that nearly all taxa obtain sufficiently high foraging efficiencies that selection for further increases in economy is weak. Thus selection pressures for increased economy and limb length among living terrestrial animals may be relatively weak and similar in magnitude across ecologically diverse species. The Economy Selection Pressure model for locomotor economy may be useful in investigating the evolution of limb design in early terrestrial taxa and the coevolution of foraging ecology and locomotor anatomy in lineages with low foraging efficiencies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of step length and step frequency on lower-limb muscle function in human gait.

PubMed

Lim, Yoong Ping; Lin, Yi-Chung; Pandy, Marcus G

2017-05-24

The aim of this study was to quantify the effects of step length and step frequency on lower-limb muscle function in walking. Three-dimensional gait data were used in conjunction with musculoskeletal modeling techniques to evaluate muscle function over a range of walking speeds using prescribed combinations of step length and step frequency. The body was modeled as a 10-segment, 21-degree-of-freedom skeleton actuated by 54 muscle-tendon units. Lower-limb muscle forces were calculated using inverse dynamics and static optimization. We found that five muscles - GMAX, GMED, VAS, GAS, and SOL - dominated vertical support and forward progression independent of changes made to either step length or step frequency, and that, overall, changes in step length had a greater influence on lower-limb joint motion, net joint moments and muscle function than step frequency. Peak forces developed by the uniarticular hip and knee extensors, as well as the normalized fiber lengths at which these muscles developed their peak forces, correlated more closely with changes in step length than step frequency. Increasing step length resulted in larger contributions from the hip and knee extensors and smaller contributions from gravitational forces (limb posture) to vertical support. These results provide insight into why older people with weak hip and knee extensors walk more slowly by reducing step length rather than step frequency and also help to identify the key muscle groups that ought to be targeted in exercise programs designed to improve gait biomechanics in older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris)

PubMed Central

Williams, S B; Wilson, A M; Daynes, J; Peckham, K; Payne, R C

2008-01-01

We provide quantitative muscle–tendon architecture and geometry data for the racing greyhound thoracic limb. Muscle mass, belly length, fascicle lengths, pennation angles and moment arms were measured, as were tendon masses and lengths. Maximum isometric force and maximum power were estimated for muscles, and maximum stress and strain were estimated for tendons. Results are compared with other fast quadrupedal runners, and to previously published data in mixed-breed dogs. The implications of the functional adaptations of the greyhound thoracic limb for sprinting performance are discussed. The thoracic limb was found to benefit from a similar proportion of locomotor muscle mass to the pelvic limb, suggesting that it may be used to some extent in propulsion, or alternatively that stabilisation is very important in this animal. Extrinsic muscles, especially latissimus dorsi and pectoralis profundus, were predicted to be powerful and important for generating net positive work during accelerations. Proximal biarticular muscles show specialisation toward preventing collapse of the shoulder and elbow joints to enable strut-like limb function, or some form of dynamic control. Distal muscles did not appear specialised for elastic energy storage, a functional difference to pelvic limb muscles, and the equivalents in horse thoracic limbs. The greyhound thoracic limb appears to possess substantial differences from both that of more ‘sub-maximal specialist’ quadrupeds, and from the greyhound pelvic limb. PMID:19034998

Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris).

PubMed

Williams, S B; Wilson, A M; Daynes, J; Peckham, K; Payne, R C

2008-10-01

We provide quantitative muscle-tendon architecture and geometry data for the racing greyhound thoracic limb. Muscle mass, belly length, fascicle lengths, pennation angles and moment arms were measured, as were tendon masses and lengths. Maximum isometric force and maximum power were estimated for muscles, and maximum stress and strain were estimated for tendons. Results are compared with other fast quadrupedal runners, and to previously published data in mixed-breed dogs. The implications of the functional adaptations of the greyhound thoracic limb for sprinting performance are discussed. The thoracic limb was found to benefit from a similar proportion of locomotor muscle mass to the pelvic limb, suggesting that it may be used to some extent in propulsion, or alternatively that stabilisation is very important in this animal. Extrinsic muscles, especially latissimus dorsi and pectoralis profundus, were predicted to be powerful and important for generating net positive work during accelerations. Proximal biarticular muscles show specialisation toward preventing collapse of the shoulder and elbow joints to enable strut-like limb function, or some form of dynamic control. Distal muscles did not appear specialised for elastic energy storage, a functional difference to pelvic limb muscles, and the equivalents in horse thoracic limbs. The greyhound thoracic limb appears to possess substantial differences from both that of more 'sub-maximal specialist' quadrupeds, and from the greyhound pelvic limb.

Scale effects and morphological diversification in hindlimb segment mass proportions in neognath birds.

PubMed

Kilbourne, Brandon M

2014-01-01

In spite of considerable work on the linear proportions of limbs in amniotes, it remains unknown whether differences in scale effects between proximal and distal limb segments has the potential to influence locomotor costs in amniote lineages and how changes in the mass proportions of limbs have factored into amniote diversification. To broaden our understanding of how the mass proportions of limbs vary within amniote lineages, I collected data on hindlimb segment masses - thigh, shank, pes, tarsometatarsal segment, and digits - from 38 species of neognath birds, one of the most speciose amniote clades. I scaled each of these traits against measures of body size (body mass) and hindlimb size (hindlimb length) to test for departures from isometry. Additionally, I applied two parameters of trait evolution (Pagel's λ and δ) to understand patterns of diversification in hindlimb segment mass in neognaths. All segment masses are positively allometric with body mass. Segment masses are isometric with hindlimb length. When examining scale effects in the neognath subclade Land Birds, segment masses were again positively allometric with body mass; however, shank, pedal, and tarsometatarsal segment masses were also positively allometric with hindlimb length. Methods of branch length scaling to detect phylogenetic signal (i.e., Pagel's λ) and increasing or decreasing rates of trait change over time (i.e., Pagel's δ) suffer from wide confidence intervals, likely due to small sample size and deep divergence times. The scaling of segment masses appears to be more strongly related to the scaling of limb bone mass as opposed to length, and the scaling of hindlimb mass distribution is more a function of scale effects in limb posture than proximo-distal differences in the scaling of limb segment mass. Though negative allometry of segment masses appears to be precluded by the need for mechanically sound limbs, the positive allometry of segment masses relative to body mass may underlie scale effects in stride frequency and length between smaller and larger neognaths. While variation in linear proportions of limbs appear to be governed by developmental mechanisms, variation in mass proportions does not appear to be constrained so.

Scale effects and morphological diversification in hindlimb segment mass proportions in neognath birds

PubMed Central

2014-01-01

Introduction In spite of considerable work on the linear proportions of limbs in amniotes, it remains unknown whether differences in scale effects between proximal and distal limb segments has the potential to influence locomotor costs in amniote lineages and how changes in the mass proportions of limbs have factored into amniote diversification. To broaden our understanding of how the mass proportions of limbs vary within amniote lineages, I collected data on hindlimb segment masses – thigh, shank, pes, tarsometatarsal segment, and digits – from 38 species of neognath birds, one of the most speciose amniote clades. I scaled each of these traits against measures of body size (body mass) and hindlimb size (hindlimb length) to test for departures from isometry. Additionally, I applied two parameters of trait evolution (Pagel’s λ and δ) to understand patterns of diversification in hindlimb segment mass in neognaths. Results All segment masses are positively allometric with body mass. Segment masses are isometric with hindlimb length. When examining scale effects in the neognath subclade Land Birds, segment masses were again positively allometric with body mass; however, shank, pedal, and tarsometatarsal segment masses were also positively allometric with hindlimb length. Methods of branch length scaling to detect phylogenetic signal (i.e., Pagel’s λ) and increasing or decreasing rates of trait change over time (i.e., Pagel’s δ) suffer from wide confidence intervals, likely due to small sample size and deep divergence times. Conclusions The scaling of segment masses appears to be more strongly related to the scaling of limb bone mass as opposed to length, and the scaling of hindlimb mass distribution is more a function of scale effects in limb posture than proximo-distal differences in the scaling of limb segment mass. Though negative allometry of segment masses appears to be precluded by the need for mechanically sound limbs, the positive allometry of segment masses relative to body mass may underlie scale effects in stride frequency and length between smaller and larger neognaths. While variation in linear proportions of limbs appear to be governed by developmental mechanisms, variation in mass proportions does not appear to be constrained so. PMID:24876886

Photometric functions for photoclinometry and other applications

USGS Publications Warehouse

McEwen, A.S.

1991-01-01

Least-squared fits to the brightness profiles across a disk or "limb darkening" described by Hapke's photometric function are found for the simpler Minnaert and lunar-Lambert functions. The simpler functions are needed to reduce the number of unknown parameters in photoclinometry, especially to distinguish the brightness variations of the surface materials from that due to the resolved topography. The limb darkening varies with the Hapke parameters for macroscopic roughness (??), the single-scattering albedo (w), and the asymmetry factor of the particle phase function (g). Both of the simpler functions generally provide good matches to the limb darkening described by Hapke's function, but the lunar-Lambert function is superior when viewing angles are high and when (??) is less than 30??. Although a nonunique solution for the Minnaert function at high phase angles has been described for smooth surfaces, the discrepancy decreases with increasing (??) and virtually disappears when (??) reaches 30?? to 40??. The variation in limb darkening with w and g, pronounced for smooth surfaces, is reduced or eliminated when the Hapke parameters are in the range typical of most planetary surfaces; this result simplifies the problem of photoclinometry across terrains with variable surface materials. The Minnaert or lunar-Lambert fits to published Hapke models will give photoclinometric solutions that are very similar (>1?? slope discrepancy) to the Hapke-function solutions for nearly all of the bodies and terrains thus far modeled by Hapke's function. ?? 1991.

Estimation of stature using lower limb measurements in Sudanese Arabs.

PubMed

Ahmed, Altayeb Abdalla

2013-07-01

The estimation of stature from body parts is one of the most vital parts of personal identification in medico-legal autopsies, especially when mutilated and amputated limbs or body parts are found. The aim of this study was to assess the reliability and accuracy of using lower limb measurements for stature estimations. The stature, tibial length, bimalleolar breadth, foot length and foot breadth of 160 right-handed Sudanese Arab subjects, 80 men and 80 women (25-30 years old), were measured. The reliability of measurement acquisition was tested prior to the primary data collection. The data were analysed using basic univariate analysis and linear and multiple regression analyses. The results showed acceptable standards of measurement errors and reliability. Sex differences were significant for all of the measurements. There was a positive correlation coefficient between lower-limb dimensions and stature (P-value < 0.01). The best predictors were tibial length and foot length. The stature prediction accuracy ranged from ± 2.75-5.40 cm, which is comparable to the established skeletal standards for the lower limbs. This study provides new forensic standards for stature estimation using the lower limb measurements of Sudanese Arabs. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

A new look at the Dynamic Similarity Hypothesis: the importance of swing phase.

PubMed

Raichlen, David A; Pontzer, Herman; Shapiro, Liza J

2013-01-01

The Dynamic Similarity Hypothesis (DSH) suggests that when animals of different size walk at similar Froude numbers (equal ratios of inertial and gravitational forces) they will use similar size-corrected gaits. This application of similarity theory to animal biomechanics has contributed to fundamental insights in the mechanics and evolution of a diverse set of locomotor systems. However, despite its popularity, many mammals fail to walk with dynamically similar stride lengths, a key element of gait that determines spontaneous speed and energy costs. Here, we show that the applicability of the DSH is dependent on the inertial forces examined. In general, the inertial forces are thought to be the centripetal force of the inverted pendulum model of stance phase, determined by the length of the limb. If instead we model inertial forces as the centripetal force of the limb acting as a suspended pendulum during swing phase (determined by limb center of mass position), the DSH for stride length variation is fully supported. Thus, the DSH shows that inter-specific differences in spatial kinematics are tied to the evolution of limb mass distribution patterns. Selection may act on morphology to produce a given stride length, or alternatively, stride length may be a "spandrel" of selection acting on limb mass distribution.

Does structural leg-length discrepancy affect postural control? Preliminary study.

PubMed

Eliks, Małgorzata; Ostiak-Tomaszewska, Wioleta; Lisiński, Przemysław; Koczewski, Paweł

2017-08-09

Leg-length inequality results in an altered position of the spine and pelvis. Previous studies on the influence of leg asymmetry on postural control have been inconclusive. The purpose of this paper was to investigate the effect of structural leg-length discrepancy (LLD) on the control of posture. We studied 38 individuals (19 patients with structural LLD, 19 healthy subjects). The examination included measurement of the length of the lower limbs and weight distribution as well as a static posturography. All statistical analyses were performed with Statistica software version 10.0. Non-parametrical Kruskal-Wallis with Dunn's post test and Spearman test were used. Differences between the groups and correlation between mean COP sway velocity and the value of LLD as well as the value of LLD and weight distribution were assumed as statistically significant at p < 0.05. There was a significant difference in the asymmetry of weight distribution between the group of patients and the healthy subjects (p = 0.0005). Differences in a posturographic examination between the groups were not statistically significant (p > 0.05). Meaningful differences in mean COP velocity in mediolateral direction between tandem stance with eyes open and closed were detected in both groups (in controls p = 0.000134, in patients both with the shorter leg in a front and rear position, p = 0.029, p = 0.026 respectively). There was a positive moderate correlation between the value of LLD and the value of mean COP velocity in normal standing in mediolateral direction with eyes open (r = 0.47) and closed (r = 0.54) and in anterioposterior plane with eyes closed (r = 0.05). The fact that there were no significant differences in posturography between the groups might indicate compensations to the altered posture and neuromuscular adaptations in patients with structural leg-length inequality. LLD causes an increased asymmetry of weight distribution. This study confirmed a fundamental role of the sight in postural control, especially in unstable conditions. The analysis of mean COP sway velocity may suggest a proportional deterioration of postural control with the increase of the value of leg-length asymmetry. Trial registry: ClinicalTrials.gov NCT03048656 , 8 February 2017 (retrospectively registered).

Computational estimation of the influence of the main body-to-iliac limb length ratio on the displacement forces acting on an aortic endograft. Theoretical application to Bolton Treovance® Abdominal Stent-Graft.

PubMed

Georgakarakos, E; Xenakis, A; Georgiadis, G S; Argyriou, C; Manopoulos, C; Tsangaris, S; Lazarides, M K

2014-10-01

The influence of the relative iliac limb length of an endograft (EG) on the displacements forces (DF) predisposing to adverse effects are under-appreciated in the literature. Therefore, we conducted a computational study to estimate the magnitude of the DF acting over an entire reconstructed EG and its counterparts for a range of main body-to-iliac limb length (L1/L2) ratios. A customary bifurcated 3D model was computationally created and meshed using the commercially available ANSYS ICEM (Ansys Inc., Canonsburg, PA, USA) software. Accordingly, Fluid Structure Interaction was used to estimate the DF. The total length of the EG was kept constant, while the L1/L2 ratio ranged from 0.3 to 1.5. The increase in L1/L2 slightly affected the DF on the EG (ranging from 3.8 to 4.1 N) and its bifurcation (4.0 to 4.6 N). However, the forces exerted at the iliac sites were strongly affected by the L1/L2 values (ranging from 0.9 to 2.2 N), showing a parabolic pattern with a minimum for 0.6 ratio. It is suggested that the hemodynamic effect of the relative limb lengths should not be considered negligible. A high main body-to-iliac limb length ratio seems to favor hemodynamically a low bifurcation but it attenuates the main body-iliac limbs modular stability. Further clinical studies should investigate the relevant value of these findings. The Bolton Treovance(®) device is presented as a representative, improved stent-graft design that takes into account these hemodynamic parameters in order to achieve a promising, improved clinical performance.

Changes in the limb kinematics and walking-distance estimation after shank elongation: evidence for a locomotor body schema?

PubMed

Dominici, Nadia; Daprati, Elena; Nico, Daniele; Cappellini, Germana; Ivanenko, Yuri P; Lacquaniti, Francesco

2009-03-01

When walking, step length provides critical information on traveled distance along the ongoing path [corrected] Little is known on the role that knowledge about body dimensions plays within this process. Here we directly addressed this question by evaluating whether changes in body proportions interfere with computation of traveled distance for targets located outside the reaching space. We studied locomotion and distance estimation in an achondroplastic child (ACH, 11 yr) before and after surgical elongation of the shank segments of both lower limbs and in healthy adults walking on stilts, designed to mimic shank-segment elongation. Kinematic analysis of gait revealed that dynamic coupling of the thigh, shank, and foot segments changed substantially as a result of elongation. Step length remained unvaried, in spite of the significant increase in total limb length ( approximately 1.5-fold). These relatively shorter strides resulted from smaller oscillations of the shank segment, as would be predicted by proportional increments in limb size and not by asymmetrical segmental increment as in the present case (length of thighs was not modified). Distance estimation was measured by walking with eyes closed toward a memorized target. Before surgery, the behavior of ACH was comparable to that of typically developing participants. In contrast, following shank elongation, the ACH walked significantly shorter distances when aiming at the same targets. Comparable changes in limb kinematics, stride length, and estimation of traveled distance were found in adults wearing on stilts, suggesting that path integration errors in both cases were related to alterations in the intersegmental coordination of the walking limbs. The results are consistent with a dynamic locomotor body schema used for controlling step length and path estimation, based on inherent relationships between gait parameters and body proportions.

Ilizarov bone transport versus fibular graft for reconstruction of tibial bone defects in children.

PubMed

Abdelkhalek, Mostafa; El-Alfy, Barakat; Ali, Ayman M

2016-11-01

The aim of this study was to compare the results of treatment of segmental tibial defects in the pediatric age group using an Ilizarov external fixator versus a nonvascularized fibular bone graft. This study included 24 patients (age range from 5.5 to 15 years) with tibial bone defects: 13 patients were treated with bone transport (BT) and 11 patients were treated with a nonvascularized fibular graft (FG). The outcome parameters were bone results (union, deformity, infection, leg-length discrepancy) and functional results: external fixation index and external fixation time. In group A (BT), one patient developed refracture at the regenerate site, whereas, in group B (FG), after removal of the external fixator, one of the FGs developed a stress fracture. The external fixator time in group A was 10.7 months (range 8-14.5) versus 7.8 months (range 4-11.5 months) in group B (FG). In group A (BT), one patient had a limb-length discrepancy (LLD), whereas, in group B (FG), three patients had LLD. The functional and bone results of the Ilizarov BT technique were excellent in 23.1 and 30.8%, good in 38.5 and 46.2, fair in 30.8 and 15.4, and poor in 7.6 and 7.6%, respectively. The poor functional result was related to the poor bone result because of prolonged external fixator time resulting in significant pain, limited ankle motion, whereas the functional and bone results of fibular grafting were excellent in 9.1 and 18.2%, good in 63.6 and 45.5%, fair in 18.2 and 27.2%, and poor in 9.1 and 9.1%, respectively. Segmental tibial defects can be effectively treated with both methods. The FG method provides satisfactory results, with early removal of the external fixator. However, it had a limitation in patients with severe infection and those with LLD. Also, it requires a long duration of limb bracing until adequate hypertrophy of the graft. The Ilizarov method has the advantages of early weight bearing, treatment of postinfection bone defect in a one-stage surgery, and the possibility to treat the associated LLD. However, it has a long external fixation time.

Reduced step length reduces knee joint contact forces during running following anterior cruciate ligament reconstruction but does not alter inter-limb asymmetry.

PubMed

Bowersock, Collin D; Willy, Richard W; DeVita, Paul; Willson, John D

2017-03-01

Anterior cruciate ligament reconstruction is associated with early onset knee osteoarthritis. Running is a typical activity following this surgery, but elevated knee joint contact forces are thought to contribute to osteoarthritis degenerative processes. It is therefore clinically relevant to identify interventions to reduce contact forces during running among individuals after anterior cruciate ligament reconstruction. The primary purpose of this study was to evaluate the effect of reducing step length during running on patellofemoral and tibiofemoral joint contact forces among people with a history of anterior cruciate ligament reconstruction. Inter limb knee joint contact force differences during running were also examined. 18 individuals at an average of 54.8months after unilateral anterior cruciate ligament reconstruction ran in 3 step length conditions (preferred, -5%, -10%). Bilateral patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, loading rate, impulse, and impulse per kilometer were evaluated between step length conditions and limbs using separate 2 factor analyses of variance. Reducing step length 5% decreased patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, impulse, and impulse per kilometer bilaterally. A 10% step length reduction further decreased peak forces and force impulses, but did not further reduce force impulses per kilometer. Tibiofemoral joint impulse, impulse per kilometer, and patellofemoral joint loading rate were lower in the previously injured limb compared to the contralateral limb. Running with a shorter step length is a feasible clinical intervention to reduce knee joint contact forces during running among people with a history of anterior cruciate ligament reconstruction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differences between orthopaedic evaluation and radiological reports of conventional radiographs in patients with minor trauma admitted to the emergency department.

PubMed

Catapano, Michele; Albano, Domenico; Pozzi, Grazia; Accetta, Riccardo; Memoria, Sergio; Pregliasco, Fabrizio; Messina, Carmelo; Sconfienza, Luca Maria

2017-11-01

During night and on weekends, in our emergency department there is no radiologist on duty or on call: thus, X-ray examinations (XR) are evaluated by the orthopaedic surgeon on duty and reported the following morning/monday by radiologists. The aim of our study was to examine the discrepancy rate between orthopaedists and radiologists in the interpretation of imaging examinations performed on patients in our tertiary level orthopaedic institution and the consequences of delayed diagnosis in terms of patient management and therapeutic strategy. We retrospectively reviewed all cases of discrepancy between orthopaedists and radiologists, which were categorized according to anatomical location of injury, initial diagnosis and treatment, change in diagnosis and treatment. We used the Chi square test to compare the frequencies of discrepancies between patients ≤14 and >14years of age. From January to December 2016, 19,512 patients admitted to our emergency department performed at least an imaging examination; among these patients, 13,561 underwent XR in absence of an attending radiologist. A discrepant diagnosis was found in 337/13,561 (2.5%; 184 males; mean age: 36.7±23.7, range 2-95); 151/337 (45%) discrepancies were encountered in the lower limbs, with ankle being the most common site of misdiagnosis (64/151), and 103/337 (30%) in the upper limbs, with the elbow being the most frequent site in this district (35/103). We found 293/337 false negatives (87%) and 44/337 false positives (13%), with 134 and 13 patients needing treatment change, respectively. We found 85/337 discrepancies (25%) in patients ≤14 years of age, and 252/337 (75%) in those >14years. The distribution of discrepancies per anatomic district was significantly different (P<0.001) in these two groups of patients. A low rate of discrepancy between orthopaedists and radiologists in evaluating images of patients admitted to our emergency department was found, although treatment change occurred in about half of cases. A thorough and accurate clinical evaluation is crucial to provide a correct treatment and prognosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimation of stature by using lower limb dimensions in the Malaysian population.

PubMed

Nor, Faridah Mohd; Abdullah, Nurliza; Mustapa, Al-Mizan; Qi Wen, Leong; Faisal, Nurulina Aimi; Ahmad Nazari, Dayang Anis Asyikin

2013-11-01

Estimation of stature is an important step in developing a biological profile for human identification. It may provide a valuable indicator for an unknown individual in a population. The aim of this study was to analyse the relationship between stature and lower limb dimensions in the Malaysian population. The sample comprised 100 corpses, which included 69 males and 31 females between the age range of 20-90 years old. The parameters measured were stature, thigh length, lower leg length, leg length, foot length, foot height and foot breadth. Results showed that the mean values in males were significantly higher than those in females (p < 0.05). There were significant correlations between lower limb dimensions and stature. Cross-validation of the equation on 100 individuals showed close approximation between known stature and estimated stature. It was concluded that lower limb dimensions were useful for estimation of stature, which should be validated in future studies. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Birth month associations with height, head circumference, and limb lengths among Peruvian children.

PubMed

Pomeroy, Emma; Wells, Jonathan C K; Stanojevic, Sanja; Miranda, J Jaime; Cole, Tim J; Stock, Jay T

2014-05-01

Associations between season of birth and body size, morbidity, and mortality have been widely documented, but it is unclear whether different parts of the body are differentially sensitive, and if such effects persist through childhood. This may be relevant to understanding the relationship between early life environment and body size and proportions. We investigated associations between birth month and anthropometry among rural highland (n = 162) and urban lowland (n = 184) Peruvian children aged 6 months to 8 years. Stature; head-trunk height; total limb, ulna, tibia, hand, and foot lengths; head circumference; and limb measurements relative to head-trunk height were converted to internal age-sex-specific z scores. Lowland and highland datasets were then analyzed separately for birth month trends using cosinor analysis, as urban conditions likely provide a more consistent environment compared with anticipated seasonal variation in the rural highlands. Among highland children birth month associations were significant most strongly for tibia length, followed by total lower limb length and stature, with a peak among November births. Results were not significant for other measurements or among lowland children. The results suggest a prenatal or early postnatal environmental effect on growth that is more marked in limb lengths than trunk length or head size, and persists across the age range studied. We suggest that the results may reflect seasonal variation in maternal nutrition in the rural highlands, but other hypotheses such as variation in maternal vitamin D levels cannot be excluded. Copyright © 2014 Wiley Periodicals, Inc.

Three-stage treatment protocol for recalcitrant distal femoral nonunion.

PubMed

Ma, Ching-Hou; Chiu, Yen-Chun; Tu, Yuan-Kun; Yen, Cheng-Yo; Wu, Chin-Hsien

2017-04-01

In this study, we proposed a three-stage treatment protocol for recalcitrant distal femoral nonunion and aimed to analyze the clinical results. We retrospective reviewed 12 consecutive patients with recalcitrant distal femoral nonunion undergoing our three-stage treatment protocol from January 2010 to December 2014 in our institute. The three-stage treatment protocol comprised debridement of the nonunion site, lengthening to eliminate leg length discrepancy, deformity correction, stabilization with a locked plate, filling of the defect with cement spacer for inducing membrane formation, and bone reconstruction using a cancellous bone autograft (Masquelet technique) or free vascularized fibular bone graft. The bone union time, wound complication, lower limbs alignment, amount of lengthening, knee range of motion, and functional outcomes were evaluated. Osseous union with angular deformity <5° and leg length discrepancy <1 cm were achieved in all the patients. The average amount of lengthening was 5.88 cm (range 3.5-12 cm). Excellent or good outcomes were obtained in 9 patients. Although the current study involved only a small number of patients and the intervention comprised three stages, we believe that such a protocol may be a valuable alternative for the treatment of recalcitrant distal femoral nonunion.

Paediatric tibial shaft fractures treated by open reduction and stabilization with monolateral external fixation

PubMed Central

Simon, A.-L.; Apostolou, N.; Vidal, C.; Ferrero, E.; Mazda, K.; Ilharreborde, B.

2018-01-01

Abstract Purpose Elastic stable intramedullary nailing is increasingly used for surgical treatment of tibial shaft fractures, but frequently requires immobilization and delayed full weight-bearing. Therefore, external fixation remains interesting. The aim was to report clinico-radiological outcomes of monolateral external fixation for displaced and unstable tibial shaft fractures in children. Methods All tibial fractures consecutively treated by monolateral external fixation between 2008 and 2013 were followed. Inclusion criteria included skeletal immaturity and closed and open Gustilo I fractures caused by a direct impact. Patients were seen until two years postoperatively. Demographics, mechanism of injury, surgical data and complications were recorded. Anteroposterior and lateral side radiographs were performed at each visit. Full-limb 3D reconstructions using biplanar stereroradiography was performed for final limb length and alignment measures. Results A total of 45 patients (mean age 9.7 years ± 0.5) were included. In all, 17 were Gustilo I fractures, with no difference between open and closed fractures for any data. Mean time to full weight bearing was 18.2 days ± 0.7. After 15 days, 39 patients returned to school. Hardware removal (mean time to union 15.6 weeks ± 0.8) was performed during consultation under analgesic gas. There were no cases of nonunion. No fracture healed with > 10° of angulation (mean 5.1° ± 0.4°). Leg-length discrepancy > 10 mm was found for six patients. Conclusions This procedure can be a safe and simple surgical treatment for children with tibial shaft fractures. Few complications and early return to school were reported, with the limitations of non-comparative study. Level of Evidence IV PMID:29456750

STIMULATION OF TARSAL RECEPTORS OF THE BLOWFLY BY ALIPHATIC ALDEHYDES AND KETONES

PubMed Central

Chadwick, L. E.; Dethier, V. G.

1949-01-01

Rejection of eight aldehydes, eight ketones, five secondary alcohols, and 3-pentanol has been studied in the blowfly Phormia regina Meigen. The data agree with results previously reported for normal alcohols and several series of glycols in showing a logarithmic increase in stimulating effect with increasing chain length. The order of increasing effectiveness among the different species of compounds thus far investigated is the following: polyglycols, diols, secondary alcohols, iso-alcohols, normal alcohols, ketones, iso-aldehydes, normal aldehydes. Curves relating the logarithms of threshold concentration to the logarithms of chain length for diols, alcohols, aldehydes, and ketones show inflections in the 3 to 6 carbon range. Above and below the region of inflection the curves are nearly rectilinear. The slopes for the upper limbs (smaller molecules) are of the order of –2; for the lower limbs, about –10. Comparisons of the threshold data with numerical values for molecular weights, molecular areas and volumes, oil-water distribution coefficients, activity coefficients, standard free energies, vapor pressures, boiling points, melting points, dipole moments, dielectric constants, and degree of association are discussed briefly, and it is concluded that none of the comparisons serves to bring the data from the several series and from the two portions of each series into a single homogeneous system. A qualitative comparison with water solubilities shows fewer discrepancies. It is suggested that the existence of a combination of aqueous and lipoid phases at the receptor surface would fit best with what is presently known about the relationship between chemical structure and stimulating effect in contact chemoreception. In this hypothesis the smaller and more highly water-soluble compounds are envisaged as gaining access to the receptors partly through the aqueous phase, the larger molecules predominantly through the lipoid phase. PMID:18114559

Effect of Limb Lengthening on Internodal Length and Conduction Velocity of Peripheral Nerve

PubMed Central

Gillingwater, Thomas H.; Anderson, Heather; Cottrell, David; Sherman, Diane L.; Ribchester, Richard R.; Brophy, Peter J.

2013-01-01

The influences of axon diameter, myelin thickness, and internodal length on the velocity of conduction of peripheral nerve action potentials are unclear. Previous studies have demonstrated a strong dependence of conduction velocity on internodal length. However, a theoretical analysis has suggested that this relationship may be lost above a nodal separation of ∼0.6 mm. Here we measured nerve conduction velocities in a rabbit model of limb lengthening that produced compensatory increases in peripheral nerve growth. Divided tibial bones in one hindlimb were gradually lengthened at 0.7 mm per day using an external frame attached to the bone. This was associated with a significant increase (33%) of internodal length (0.95–1.3 mm) in axons of the tibial nerve that varied in proportion to the mechanical strain in the nerve of the lengthened limb. Axonal diameter, myelin thickness, and g-ratios were not significantly altered by limb lengthening. Despite the substantial increase in internodal length, no significant change was detected in conduction velocity (∼43 m/s) measured either in vivo or in isolated tibial nerves. The results demonstrate that the internode remains plastic in the adult but that increases in internodal length of myelinated adult nerve axons do not result in either deficiency or proportionate increases in their conduction velocity and support the view that the internodal lengths of nerves reach a plateau beyond which their conduction velocities are no longer sensitive to increases in internodal length. PMID:23467369

Stature Estimation from Lower Limb Anthropometry using Linear Regression Analysis: A Study on the Malaysian Population.

PubMed

Abu Bakar, S N; Aspalilah, A; AbdelNasser, I; Nurliza, A; Hairuliza, M J; Swarhib, M; Das, S; Mohd Nor, F

2017-01-01

Stature is one of the characteristics that could be used to identify human, besides age, sex and racial affiliation. This is useful when the body found is either dismembered, mutilated or even decomposed, and helps in narrowing down the missing person's identity. The main aim of the present study was to construct regression functions for stature estimation by using lower limb bones in the Malaysian population. The sample comprised 87 adult individuals (81 males, 6 females) aged between 20 to 79 years. The parameters such as thigh length, lower leg length, leg length, foot length, foot height and foot breadth were measured. They were measured by a ruler and measuring tape. Statistical analysis involved independent t-test to analyse the difference between lower limbs in male and female. The Pearson's correlation test was used to analyse correlations between lower limb parameters and stature, and the linear regressions were used to form equations. The paired t-test was used to compare between actual stature and estimated stature by using the equations formed. Using independent t-test, there was a significant difference (p< 0.05) in the measurement between males and females with regard to leg length, thigh length, lower leg length, foot length and foot breadth. The thigh length, leg length and foot length were observed to have strong correlations with stature with p= 0.75, p= 0.81 and p= 0.69, respectively. Linear regressions were formulated for stature estimation. Paired t-test showed no significant difference between actual stature and estimated stature. It is concluded that regression functions can be used to estimate stature to identify skeletal remains in the Malaysia population.

Upper limb load as a function of repetitive task parameters: part 1--a model of upper limb load.

PubMed

Roman-Liu, Danuta

2005-01-01

The aim of the study was to develop a theoretical indicator of upper limb musculoskeletal load based on repetitive task parameters. As such the dimensionless parameter, Integrated Cycle Load (ICL) was accepted. It expresses upper limb load which occurs during 1 cycle. The indicator is based on a model of a repetitive task, which consists of a model of the upper limb, a model of basic types of upper limb forces and a model of parameters of a repetitive task such as length of the cycle, length of periods of the cycle and external force exerted during each of the periods of the cycle. Calculations of the ICL parameter were performed for 12 different variants of external load characterised by different values of repetitive task parameters. A comparison of ICL, which expresses external load with a physiological indicator of upper limb load, is presented in Part 2 of the paper.

Body size and lower limb posture during walking in humans.

PubMed

Hora, Martin; Soumar, Libor; Pontzer, Herman; Sládek, Vladimír

2017-01-01

We test whether locomotor posture is associated with body mass and lower limb length in humans and explore how body size and posture affect net joint moments during walking. We acquired gait data for 24 females and 25 males using a three-dimensional motion capture system and pressure-measuring insoles. We employed the general linear model and commonality analysis to assess the independent effect of body mass and lower limb length on flexion angles at the hip, knee, and ankle while controlling for sex and velocity. In addition, we used inverse dynamics to model the effect of size and posture on net joint moments. At early stance, body mass has a negative effect on knee flexion (p < 0.01), whereas lower limb length has a negative effect on hip flexion (p < 0.05). Body mass uniquely explains 15.8% of the variance in knee flexion, whereas lower limb length uniquely explains 5.4% of the variance in hip flexion. Both of the detected relationships between body size and posture are consistent with the moment moderating postural adjustments predicted by our model. At late stance, no significant relationship between body size and posture was detected. Humans of greater body size reduce the flexion of the hip and knee at early stance, which results in the moderation of net moments at these joints.

Scaling and functional morphology in strigiform hind limbs

PubMed Central

Madan, Meena A.; Rayfield, Emily J.; Bright, Jen A.

2017-01-01

Strigiformes are an order of raptorial birds consisting exclusively of owls: the Tytonidae (barn owls) and the Strigidae (true owls), united by a suite of adaptations aiding a keen predatory lifestyle, including robust hind limb elements modified for grip strength. To assess variation in hind limb morphology, we analysed how the dimensions of the major hind limb elements in subfossil and modern species scaled with body mass. Comparing hind limb element length, midshaft width, and robusticity index (RI: ratio of midshaft width to maximum length) to body mass revealed that femoral and tibiotarsal width scale with isometry, whilst length scales with negative allometry, and close to elastic similarity in the tibiotarsus. In contrast, tarsometatarsus width shows strong positive allometry with body mass, whilst length shows strong negative allometry. Furthermore, the tarsometatarsi RI scales allometrically to mass0.028, whilst a weak relationship exists in femora (mass0.004) and tibiotarsi (mass0.004). Our results suggest that tarsometatarsi play a more substantial functional role than tibiotarsi and femora. Given the scaling relationship between tarsometatarsal width and robusticity to body mass, it may be possible to infer the body mass of prehistoric owls by analysing tarsometatarsi, an element that is frequently preserved in the fossil record of owls. PMID:28327549

Knee arthrodesis with lengthening: experience of using Ilizarov techniques to salvage large asymmetric defects following infected peri-articular fractures.

PubMed

Barwick, Thomas W; Montgomery, Richard J

2013-08-01

We present four patients with large bone defects due to infected internal fixation of knee condylar fractures. All were treated by debridement of bone and soft tissue and stabilisation with flap closure if required, followed by bone transport arthrodesis of the knee with simultaneous lengthening. Four patients (three male and one female), mean age 46.5 years (37-57 years), with posttraumatic osteomyelitis at the knee (three proximal tibia and one distal femur) were treated by debridement of infected tissue and removal of internal fixation. Substantial condylar bone defects resulted on the affected side of the knee joint (6-10 cm) with loss of the extensor mechanism in all tibial cases. Two patients required muscle flaps after debridement. All patients received intravenous antibiotics for at least 6 weeks. Bone transport with a circular frame was used to achieve an arthrodesis whilst simultaneously restoring a functional limb length. In three cases a 'peg in socket' docking technique was fashioned to assist stability and subsequent consolidation of the arthrodesis. Arthrodesis of the knee, free of recurrent infection, was successfully achieved in all cases. None has since required further surgery. Debridement to union took an average of 25 months (19-31 months). The median number of interventions undertaken was 9 (8-12). Two patients developed deep vein thrombosis (DVT), one complicated by PE, which delayed treatment. Two required surgical correction of pre-existent equinus contracture using frames. The median limb length discrepancy (LLD) at the end of treatment was 3 cm (3-4 cm). None has required subsequent amputation. Bone loss and infection both reduce the success rate of any arthrodesis. However, by optimising the host environment with eradication of infection by radical debridement, soft-tissue flaps when necessary and bone transport techniques to close the defect, one can achieve arthrodesis and salvage a useful limb. The residual LLD can result from not accounting for later impaction at peg and socket sites, which had the effect of increasing LLD beyond the desirable amount. We therefore recommend continuing the lengthening for an additional 1-2 cm to allow for this. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dual-fibular reconstruction of a massive tibial defect after Ewing's sarcoma resection in a pediatric patient with a vascular variation.

PubMed

Saridis, Alkis G; Megas, Panagiotis D; Georgiou, Christos S; Diamantakis, Georgios M; Tyllianakis, Minos E

2011-01-01

In the management of malignancies of the extremities, limb salvage procedures have recently taken on greater significance. For those patients under intense adjuvant chemotherapy and with massive bone loss, free vascularized fibular grafting is currently advocated as a reliable reconstructive option, maybe because of the controversial results of bone transport in similar situations. However, when there is a vascular abnormality of either the recipient or donor extremity, microsurgical procedures are not feasible, further limiting potential reconstructive alternatives. We present the case of a 13-year-old female patient with Ewing's sarcoma of the right tibia. Preoperative angiography showed that vascularity of the affected side depended totally on a single peroneal artery. The patient was treated initially with multiagent chemotherapy, followed by an excision of 23 cm. The defect was bridged by a gradual medial transportation of the ipsilateral fibula with the Ilizarov technique and strengthened by nonvascularized transfer of the contralateral fibula. Total external fixation time was 162 days. After the removal of the Ilizarov frame a walking cast was applied for another month. At 5 years postoperatively there was no recurrence of the malignancy. The patient had full weight-bearing ability on the affected limb, with preservation of the ankle and knee joints motion and without any limb length discrepancy or axial deformity. The functional outcome that was visible was graded excellent. Transverse distraction osteogenesis of the ipsilateral fibula performed well under chemotherapy, showing unproblematic callus formation. Supplemented with nonvascularized transfer of the contralateral fibula, provided a reconstructive option with biological affinity, sufficient biomechanical strength and durability, and with a decreased complication rate. This case report presents a viable option, especially in cases in which vascular abnormalities of either the donor or the recipient limb, combined with multiagent chemotherapy, restrict potential reconstructive alternatives. It also highlights why vascularized bone graft should not be regarded as a panacea for all situations in which a fibular graft is required. Level IV, case report.

Ontogenetic changes in limb bone structural proportions in mountain gorillas (Gorilla beringei beringei).

PubMed

Ruff, Christopher B; Burgess, M Loring; Bromage, Timothy G; Mudakikwa, Antoine; McFarlin, Shannon C

2013-12-01

Behavioral studies indicate that adult mountain gorillas (Gorilla beringei) are the most terrestrial of all nonhuman hominoids, but that infant mountain gorillas are much more arboreal. Here we examine ontogenetic changes in diaphyseal strength and length of the femur, tibia, humerus, radius, and ulna in 30 Virunga mountain gorillas, including 18 immature specimens and 12 adults. Comparisons are also made with 14 adult western lowland gorillas (Gorilla gorilla gorilla), which are known to be more arboreal than adult mountain gorillas. Infant mountain gorillas have significantly stronger forelimbs relative to hind limbs than older juveniles and adults, but are nonsignificantly different from western lowland gorilla adults. The change in inter-limb strength proportions is abrupt at about two years of age, corresponding to the documented transition to committed terrestrial quadrupedalism in mountain gorillas. The one exception is the ulna, which shows a gradual increase in strength relative to the radius and other long bones during development, possibly corresponding to the gradual adoption of stereotypical fully pronated knuckle-walking in older juvenile gorillas. Inter-limb bone length proportions show a contrasting developmental pattern, with hind limb/forelimb length declining rapidly from birth to five months of age, and then showing no consistent change through adulthood. The very early change in length proportions, prior to significant independent locomotion, may be related to the need for relatively long forelimbs for climbing in a large-bodied hominoid. Virunga mountain gorilla older juveniles and adults have equal or longer forelimb relative to hind limb bones than western lowland adults. These findings indicate that both ontogenetically and among closely related species of Gorilla, long bone strength proportions better reflect actual locomotor behavior than bone length proportions. Copyright © 2013 Elsevier Ltd. All rights reserved.

A large-scale intercomparison of stratospheric vertical distributions of NO2 and BrO retrieved from the SCIAMACHY limb measurements and ground-based twilight observations

NASA Astrophysics Data System (ADS)

Rozanov, Alexei; Hendrick, Francois; Lotz, Wolfhardt; van Roozendael, Michel; Bovensmann, Heinrich; Burrows, John P.

This study is devoted to the intercomparison of NO2 and BrO vertical profiles obtained from the satellite and ground-based measurements. Although, the ground-based observations are performed only at selected locations, they have a great potential to be used for the validation of satellite measurements since continuous long-term measurement series performed with the same instruments are available. Thus, long-term trends in the observed species can be analyzed and intercompared. Previous intercomparisons of the vertical distributions of NO2 and BrO retrieved from SCIAMACHY limb measurements at the University of Bremen and obtained at IASB-BIRA by applying a profiling technique to ground-based zenith-sky DOAS observations have shown a good agreement between the results of completely different measurement techniques. However, only a relatively short time period of one year was analyzed so far which do not allow investigating seasonal variations and trends. Furthermore, some minor discrepancies are still to be analyzed. In the current study, several years datasets obtained at Observatoire de Haute-Provence (OHP) in France and in Harestua in Norway will be compared to the retrievals of SCIAMACHY limb measurements. Seasonal and annual variations will be analyzed and possible reasons for the remaining discrepancies will be discussed.

Limb Correction of Polar-Orbiting Imagery for the Improved Interpretation of RGB Composites

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Elmer, Nicholas

2016-01-01

Red-Green-Blue (RGB) composite imagery combines information from several spectral channels into one image to aid in the operational analysis of atmospheric processes. However, infrared channels are adversely affected by the limb effect, the result of an increase in optical path length of the absorbing atmosphere between the satellite and the earth as viewing zenith angle increases. This paper reviews a newly developed technique to quickly correct for limb effects in both clear and cloudy regions using latitudinally and seasonally varying limb correction coefficients for real-time applications. These limb correction coefficients account for the increase in optical path length in order to produce limb-corrected RGB composites. The improved utility of a limb-corrected Air Mass RGB composite from the application of this approach is demonstrated using Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. However, the limb correction can be applied to any polar-orbiting sensor infrared channels, provided the proper limb correction coefficients are calculated. Corrected RGB composites provide multiple advantages over uncorrected RGB composites, including increased confidence in the interpretation of RGB features, improved situational awareness for operational forecasters, and the ability to use RGB composites from multiple sensors jointly to increase the temporal frequency of observations.

THE DIFFUSION LENGTH OF THERMAL NEUTRONS IN PORTLAND CONCRETE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dugdale, R.A.; Healy, E.

1957-10-01

A measurement of the diffusion length of thermal neutrons in Portland concrete, originally raade by Salmon two years previously, has been repeated. An apparent decrease from 7.04 cm to 6.61 cm has oocurred. This change, which is only four times the standard deviation of the result, could be due to a small increase in water content. In assessing the amount required, a discrepancy between calculated and measured diffusion length was found. Possible explanations of the discrepancy are discussed. (auth)

The management of the neglected congenital foot deformity in the older child with the Taylor spatial frame.

PubMed

Hassan, Atef; Letts, Merv

2012-01-01

Neglected or inadequately treated rigid congenitally deformed feet in older children are a nightmarish challenge for the child, the parents, and the orthopaedic surgeon. Because of the multiplicity of spatial deformities exhibited by these feet and legs, it was hypothesized that correction using the Taylor spatial frame (TSF) would decrease morbidity, facilitate correction, and minimize treatment time in children from remote regions with extremely rigid deformed feet. Recent experience with the management of 11 such feet (Dimeglio type IV) in 9 children with an average age of 9.2 years using the TSF has been gratifying. Six children had associated leg length discrepancy, which was corrected by concomitant tibial lengthening. All feet underwent soft tissue releases, whereas forefoot and/or hindfoot osteotomies were performed in 7 feet. All children attained plantigrade, functional feet, and were fully ambulatory and capable of wearing normal footwear. Complications were minor consisting of pin tract infections, residual metatarsus varus in 3, and wound dehiscence in 1. There were no neurovascular events. This was attributed to the slower 3 plane correction using the TSF technique as well as the elimination of the need for plaster immobilization thus allowing direct monitoring of the foot and limb. The rigid foot deformity in the older child can be safely and effectively corrected with the aid of the TSF, which facilitates a 3 plane correction and concomitant limb lengthening.

Kinetic and temporospatial parameters in male and female cats walking over a pressure sensing walkway.

PubMed

Verdugo, Mirela R; Rahal, Sheila C; Agostinho, Felipe S; Govoni, Verônica M; Mamprim, Maria J; Monteiro, Frederico O B

2013-06-27

Several factors may influence kinetic data measurements, including body conformation and body mass. In addition, gender differences in gait pattern have been observed in healthy humans. Therefore, the aim of this study was to compare the kinetic and temporospatial parameters in clinically healthy male and female cats using a pressure-sensitive walkway. Eighteen crossbreed adult cats were divided into two groups: G1 had ten male cats (nine neutered) aged from 1 to 4 years and body mass 3.1-6.8 kg; G2 had eight spayed female cats, aged from 1 to 6 years and body mass 3.3-4.75 kg. The data from the first five valid trials were collected for each cat. A trial was considered valid if the cat maintained a velocity between 0.54-0.74 m/s and acceleration from -0.20 to 0.20 m/s2. The peak vertical force (PVF), vertical impulse (VI), gait cycle time, stance time, swing time, stride length, and percentage body weight distribution among the four limbs were determined. In addition, the lengths of each forelimb and each hind limb were measured using a tape with the animal standing. No significant differences were observed in each group in either the forelimbs or the hind limbs or between the left and right sides for any of the variables. For both groups, the PVF (%BW), the VI, and the percentage body weight distribution were higher at the forelimbs than the hind limbs. The stride length was larger for males; however, the other kinetic and temporospatial variables did not show any statistically significant differences between the groups. The lengths of the forelimbs and hind limbs were larger in the male cats. There was a significant moderate positive correlation between the stride length and the length of the limbs. In conclusion, the only difference observed between male and female cats was the stride length, and this was due to the greater body size of male cats. This difference did not affect other temporospatial or kinetics variables.

Relationships of 35 lower limb muscles to height and body mass quantified using MRI.

PubMed

Handsfield, Geoffrey G; Meyer, Craig H; Hart, Joseph M; Abel, Mark F; Blemker, Silvia S

2014-02-07

Skeletal muscle is the most abundant tissue in the body and serves various physiological functions including the generation of movement and support. Whole body motor function requires adequate quantity, geometry, and distribution of muscle. This raises the question: how do muscles scale with subject size in order to achieve similar function across humans? While much of the current knowledge of human muscle architecture is based on cadaver dissection, modern medical imaging avoids limitations of old age, poor health, and limited subject pool, allowing for muscle architecture data to be obtained in vivo from healthy subjects ranging in size. The purpose of this study was to use novel fast-acquisition MRI to quantify volumes and lengths of 35 major lower limb muscles in 24 young, healthy subjects and to determine if muscle size correlates with bone geometry and subject parameters of mass and height. It was found that total lower limb muscle volume scales with mass (R(2)=0.85) and with the height-mass product (R(2)=0.92). Furthermore, individual muscle volumes scale with total muscle volume (median R(2)=0.66), with the height-mass product (median R(2)=0.61), and with mass (median R(2)=0.52). Muscle volume scales with bone volume (R(2)=0.75), and muscle length relative to bone length is conserved (median s.d.=2.1% of limb length). These relationships allow for an arbitrary subject's individual muscle volumes to be estimated from mass or mass and height while muscle lengths may be estimated from limb length. The dataset presented here can further be used as a normative standard to compare populations with musculoskeletal pathologies. © 2013 Published by Elsevier Ltd.

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort.

PubMed

Pomeroy, Emma; Wells, Jonathan C K; Cole, Tim J; O'Callaghan, Michael; Stock, Jay T

2015-04-01

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal "head and trunk skeletal size," "adiposity," and "limb lengths." Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. © 2014 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort

PubMed Central

Pomeroy, Emma; Wells, Jonathan CK; Cole, Tim J; O'Callaghan, Michael; Stock, Jay T

2015-01-01

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal “head and trunk skeletal size,” “adiposity,” and “limb lengths.” Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. Am J Phys Anthropol 156:625–636, 2015. PMID:25502164

Body size and lower limb posture during walking in humans

PubMed Central

Hora, Martin; Soumar, Libor; Pontzer, Herman; Sládek, Vladimír

2017-01-01

We test whether locomotor posture is associated with body mass and lower limb length in humans and explore how body size and posture affect net joint moments during walking. We acquired gait data for 24 females and 25 males using a three-dimensional motion capture system and pressure-measuring insoles. We employed the general linear model and commonality analysis to assess the independent effect of body mass and lower limb length on flexion angles at the hip, knee, and ankle while controlling for sex and velocity. In addition, we used inverse dynamics to model the effect of size and posture on net joint moments. At early stance, body mass has a negative effect on knee flexion (p < 0.01), whereas lower limb length has a negative effect on hip flexion (p < 0.05). Body mass uniquely explains 15.8% of the variance in knee flexion, whereas lower limb length uniquely explains 5.4% of the variance in hip flexion. Both of the detected relationships between body size and posture are consistent with the moment moderating postural adjustments predicted by our model. At late stance, no significant relationship between body size and posture was detected. Humans of greater body size reduce the flexion of the hip and knee at early stance, which results in the moderation of net moments at these joints. PMID:28192522

Knee arthrodesis with the Vari-Wall nail for treatment of infected total knee arthroplasty.

PubMed

Garcia-Lopez, Ignacio; Aguayo, Miguel Anguel; Cuevas, Antonio; Navarro, Pablo; Prieto, Cristobal; Carpintero, Pedro

2008-12-01

We reviewed 20 patients who had undergone one-stage (7 cases) or two-stage (13 cases) knee arthrodesis using the Vari-Wall intramedullary nail, as a salvage operation following infection of a total knee arthroplasty. The procedure was followed by systemic antibiotic administration and early rehabilitation. Intraoperative microbiological cultures were taken. The average period of follow-up was 20 months. Solid union was achieved in 80%; mean time to fusion was 9 months. There was no recurrence of infection. The average limb length discrepancy was 2.45 cm. A walking aid was needed by 95% of the patients. The complication rate was 30% including 4 pseudarthroses, one intraoperative fracture and one peroneal nerve palsy. The Vari-Wall intramedullary nail is a good option when an arthrodesis is indicated for salvage of an infected total knee arthroplasty. It can be performed in one or two stages depending on several factors such as microbiologic culture results. It achieved good pain relief and acceptable functional results in this study.

Functional outcome of knee arthrodesis with a monorail external fixator.

PubMed

Roy, Alfred Cyril; Albert, Sandeep; Gouse, Mohamad; Inja, Dan Barnabas

2016-04-01

Several methods for obtaining knee arthrodesis have been described in the literature and world; over, the commonest cause for arthrodesis is a failed arthroplasty. Less commonly, as in this series, post-infective or traumatic causes may also require a knee fusion wherein arthroplasty may not be indicated. We present salient advantages along with the radiological and functional outcome of twenty four patients treated with a single monorail external fixator. All patients went on develop fusion at an average of 5.4 months with an average limb length discrepancy of 3 cm (1.5-6 cm). Improvements in functional outcome as assessed by the lower extremity functional score (LEFS), and the SF-36 was significant (p = 0.000). Knee arthrodesis with a single monorail external fixator is a reasonable single-staged salvage option in patients wherein arthroplasty may not be the ideal choice. The outcome, though far from ideal, is definitely positive and predictable.

Effect of Prior Injury on Changes to Biceps Femoris Architecture across an Australian Football League Season.

PubMed

Timmins, Ryan G; Bourne, Matthew N; Hickey, Jack T; Maniar, Nirav; Tofari, Paul J; Williams, Morgan D; Opar, David A

2017-10-01

To assess in-season alterations of biceps femoris long head (BFlh) fascicle length in elite Australian footballers with and without a history of unilateral hamstring strain injury (HSI) in the past 12 months. Thirty elite Australian football players were recruited. Twelve had a history of unilateral HSI. Eighteen had no HSI history. All had their BFlh architecture assessed at approximately monthly intervals, six times across a competitive season. The previously injured limb's BFlh fascicles increased from the start of the season and peaked at week 5. Fascicle length gradually decreased until the end of the season, where they were shortest. The contralateral uninjured limb's fascicles were the longest when assessed at week 5 and showed a reduction in-season where weeks 17 and 23 were shorter than week 1. Control group fascicles were longest at week 5 and reduced in-season. The previously injured limb's BFlh fascicles were shorter than the control group at all weeks and the contralateral uninjured limb at week 5. Compared with the control group, the contralateral uninjured limb had shorter fascicles from weeks 9 to 23. Athletes with a history of HSI end the season with shorter fascicles than they start. Limbs without a history of HSI display similar BFlh fascicle lengths at the end of the season as they begin with. All athletes increase fascicle length at the beginning of the season; however, the extent of the increase differed based on history of HSI. These findings show that a HSI history may influence structural adaptation of the BFlh in-season.

Evaluation of different captive bolt lengths and breed influence upon post-stun hind limb and forelimb activity in fed cattle at a commercial slaughter facility.

PubMed

Martin, Miriam S; Kline, Helen C; Wagner, Dana R; Alexander, Lacey R; Edwards-Callaway, Lily N; Grandin, Temple

2018-05-03

The objective of this study was to assess the effects of captive bolt length and breed type on post-stun leg activity in cattle. A total of 2850 Holstein (HOL) and non-Holstein British/Continental bred (NHOL) steers and heifers were observed post-stunning at a large commercial slaughter facility. A pneumatically powered penetrating captive bolt stunner was used with three different bolt lengths: CON, 15.24 cm; MED, 16.51 cm; and LON, 17.78 cm. Hind limb kicking, forelimb activity, take away belt stops, carcass swing and number of knife sticks during exsanguination were recorded for each animal from video recording. Hind limb and forelimb kicks observed ranged from 0 to 25 and 0 to 8, respectively. Analysis of post-stun hind limb and forelimb activity indicated that increasing pneumatically powered penetrating captive bolt length does not decrease post-stun leg activity. There was a higher percentage of cattle experiencing take away belt stops and carcass swing in HOL as compared with NHOL. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Amputation and prosthesis implantation shape body and peripersonal space representations

PubMed Central

Canzoneri, Elisa; Marzolla, Marilena; Amoresano, Amedeo; Verni, Gennaro; Serino, Andrea

2013-01-01

Little is known about whether and how multimodal representations of the body (BRs) and of the space around the body (Peripersonal Space, PPS) adapt to amputation and prosthesis implantation. In order to investigate this issue, we tested BR in a group of upper limb amputees by means of a tactile distance perception task and PPS by means of an audio-tactile interaction task. Subjects performed the tasks with stimulation either on the healthy limb or the stump of the amputated limb, while wearing or not wearing their prosthesis. When patients performed the tasks on the amputated limb, without the prosthesis, the perception of arm length shrank, with a concurrent shift of PPS boundaries towards the stump. Conversely, wearing the prosthesis increased the perceived length of the stump and extended the PPS boundaries so as to include the prosthetic hand, such that the prosthesis partially replaced the missing limb. PMID:24088746

On the atmospheric photochemistry of nitric acid

NASA Technical Reports Server (NTRS)

Austin, J.; Garcia, R. R.; Russell, J. M., III; Solomon, S.; Tuck, A. F.

1986-01-01

Measurements of the temporal and spatial variations in HNO3, particularly those from the Nimbus 7 limb IR monitor of the stratosphere (LIMS) satellite experiment, are compared to both a two-dimensional chemical/dynamical model and to chemistry/parcel trajectory analyses. Significant discrepancies are found between the observed and modeled variations in the winter season, especially in the polar night region. The study of the evolution of HNO3 suggests that an important source exists for this species in the high-latitude winter stratosphere that is not included in presently accepted photochemical schemes. Possible reactions to account for this discrepancy are explored.

Associations Between Arterial Oxygen Saturation, Body Size and Limb Measurements Among High-Altitude Andean Children

PubMed Central

Pomeroy, Emma; Stock, Jay T; Stanojevic, Sanja; Miranda, J Jaime; Cole, Tim J; Wells, Jonathan CK

2013-01-01

Objectives The relative influences of hypoxia and other environmental stressors on growth at altitude remain unclear. Previous work demonstrated an association between peripheral arterial oxygen saturation (SpO2) and anthropometry (especially tibia length) among Tibetan and Han children at altitude. We investigated whether similar associations exist among Andeans, and the patterning of associations between SpO2 and anthropometry. Methods Stature, head-trunk height, total upper and lower limb lengths, zeugopod (ulna and tibia) and autopod (hand and foot) lengths were measured in Peruvian children (0.5–14 years) living at >3000 m altitude. SpO2 was measured by pulse oximetry. Anthropometry was converted to internal z scores. Correlation and multiple regression were used to examine associations between anthropometry z scores and SpO2, altitude, or SpO2 adjusted for altitude since altitude is a major determinant of variation in SpO2. Results SpO2 and altitude show weak, significant correlations with zeugopod length z scores and still weaker significant correlations with total upper and lower limb length z scores. Correlations with z scores for stature, head-trunk height, or autopod lengths are not significant. Adjusted for altitude, there is no significant association between anthropometry and SpO2. Conclusions Associations between SpO2 or altitude and total limb and zeugopod length z scores exist among Andean children. However, the relationships are relatively weak, and while the relationship between anthropometry and altitude may be partly mediated by SpO2, other factors that covary with altitude (e.g., socioeconomic status, health) are likely to influence anthropometry. The results support suggestions that zeugopod lengths are particularly sensitive to environmental stressors. Am. J. Hum. Biol., 25:629–636, 2013. © 2013 Wiley Periodicals, Inc. PMID:23904412

Falls in Korean Polio Survivors: Incidence, Consequences, and Risk Factors

PubMed Central

Lee, SeungYeol; Yang, Eun Joo; Kim, Keewon; Jung, Se Hee; Jang, Soong-Nang; Han, Soo Jeong; Kim, Wan-Ho

2016-01-01

Falls and fall-related injuries are important issue among polio survivors. The purpose of this study was to determine the incidence of, and consequences and factors associated with falls among Korean polio survivors. A total of 317 polio survivors participated in this study. All participants completed a questionnaire including fall history, symptoms related to post-polio syndrome and other information through a telephone interview. Among them, 80 participants visited our clinic for additional physical measurements and tests. Of the 317 respondents, 68.5% reported at least one fall in the past year. Of the fallers, 42.5% experienced at least one fall during one month. Most falls occurred during ambulation (76.6%), outside (75.2%) and by slipping down (29.7%). Of fallers, 45% reported any injuries caused by falls, and 23.3% reported fractures specifically. Female sex, old age, low bone mineral density, the presence of symptoms related to post-polio syndrome (PPS), poor balance confidence, short physical performance battery and weak muscle strength of knee extensor were not significantly associated with falls. Only leg-length discrepancy using spine-malleolar distance (SMD) was a significant factor associated with falls among Korean polio survivors. Our findings suggest that malalignment between the paralytic and non-paralytic limb length should be addressed in polio survivors for preventing falls. PMID:26839487

Falls in Korean Polio Survivors: Incidence, Consequences, and Risk Factors.

PubMed

Nam, Ki Yeun; Lee, SeungYeol; Yang, Eun Joo; Kim, Keewon; Jung, Se Hee; Jang, Soong-Nang; Han, Soo Jeong; Kim, Wan-Ho; Lim, Jae-Young

2016-02-01

Falls and fall-related injuries are important issue among polio survivors. The purpose of this study was to determine the incidence of, and consequences and factors associated with falls among Korean polio survivors. A total of 317 polio survivors participated in this study. All participants completed a questionnaire including fall history, symptoms related to post-polio syndrome and other information through a telephone interview. Among them, 80 participants visited our clinic for additional physical measurements and tests. Of the 317 respondents, 68.5% reported at least one fall in the past year. Of the fallers, 42.5% experienced at least one fall during one month. Most falls occurred during ambulation (76.6%), outside (75.2%) and by slipping down (29.7%). Of fallers, 45% reported any injuries caused by falls, and 23.3% reported fractures specifically. Female sex, old age, low bone mineral density, the presence of symptoms related to post-polio syndrome (PPS), poor balance confidence, short physical performance battery and weak muscle strength of knee extensor were not significantly associated with falls. Only leg-length discrepancy using spine-malleolar distance (SMD) was a significant factor associated with falls among Korean polio survivors. Our findings suggest that malalignment between the paralytic and non-paralytic limb length should be addressed in polio survivors for preventing falls.

Growth disturbance after lengthening of the lower limb and quantitative assessment of physeal closure in skeletally immature patients with achondroplasia.

PubMed

Song, S H; Kim, S E; Agashe, M V; Lee, H; Refai, M A; Park, Y E; Choi, H J; Park, J H; Song, H R

2012-04-01

This study evaluated the effect of limb lengthening on longitudinal growth in patients with achondroplasia. Growth of the lower extremity was assessed retrospectively by serial radiographs in 35 skeletally immature patients with achondroplasia who underwent bilateral limb lengthening (Group 1), and in 12 skeletally immature patients with achondroplasia who did not (Group 2). In Group 1, 23 patients underwent only tibial lengthening (Group 1a) and 12 patients underwent tibial and femoral lengthening sequentially (Group 1b). The mean lengthening in the tibia was 9.2 cm (59.5%) in Group 1a, and 9.0 cm (58.2%) in the tibia and 10.2 cm (54.3%) in the femur in Group 1b. The mean follow-up was 9.3 years (8.6 to 10.3). The final mean total length of lower extremity in Group 1a was 526.6 mm (501.3 to 552.9) at the time of skeletal maturity and 610.1 mm (577.6 to 638.6) in Group 1b, compared with 457.0 mm (411.7 to 502.3) in Group 2. However, the mean actual length, representing the length solely grown from the physis without the length of distraction, showed that there was a significant disturbance of growth after limb lengthening. In Group 1a, a mean decrease of 22.4 mm (21.3 to 23.1) (4.9%) was observed in the actual limb length when compared with Group 2, and a greater mean decrease of 38.9 mm (37.2 to 40.8) (8.5%) was observed in Group 1b when compared with Group 2 at skeletal maturity. In Group 1, the mean actual limb length was 16.5 mm (15.8 to 17.2) (3.6%) shorter in Group 1b when compared with Group 1a at the time of skeletal maturity. Premature physeal closure was seen mostly in the proximal tibia and the distal femur with relative preservation of proximal femur and distal tibia. We suggest that significant disturbance of growth can occur after extensive limb lengthening in patients with achondroplasia, and therefore, this should be included in pre-operative counselling of these patients and their parents.

Growth and differentiation of mammalian embryonic tissues exposed to hypergravity in vivo and in vitro

NASA Technical Reports Server (NTRS)

Duke, J.; Janer, L.; Moore, J.

1985-01-01

Decreased cartilage areas in embryonic limbs developing under excess g in vitro, is reported, as well as delayed skeletal development in embryos and fetuses exposed to excess g in utero. 12.5-day mouse limb buds were cultured at 2.6 g, and fixed at two days and six days of culture. In vivo experiments used alizarin-stained 18-day fetuses exposed to 2.3 g. In all studies, cartilage areas were determined using a digitized tablet. Form factor analysis determined that the main effect of in vitro centrifugation was a reduction in length of the limb elements, probably due to the precocious chondrogenesis seen in the upper regions of centrifuged limbs. Similar reductions in length of ossified areas was seen in the in utero studies.

Revision of the genus Campylaimus (Diplopeltidae, Nematoda) with description of four new species from the Sea of Japan.

PubMed

Fadeeva, Natalia; Mordukhovich, Vladimir; Zograf, Julia

2016-05-02

Four new Campylaimus species are described from the deep-sea sediments of the Sea of Japan at depths of about 500‒3400 m. Campylaimus orientalis sp. nov. is characterized by having a body of moderate length, clearly annulated cuticle, a small rhomboid mouth opening which is displaced on the dorsal side of body, a gap between the unequal limbs of the amphid, prominent narrow longitudinal alae and cephalated spicules. Campylaimus minutus sp. nov. is characterized by having a cylindrical body, very weak annulations, amphids with a short dorsal limb (25-44% of pharynx length) and a ventral limb completely fused with lateral alae of equal width; and lateral alae extending from the base of the amphid to the tail tip. Campylaimus amphidialis sp. nov. is characterized by having the combination of a very long amphidial fovea occupying nearly the entire length of the pharynx; and a well defined boundary between the ventral amphid limb and lateral alae. The distinctive feature of Campylaimus pulcher sp. nov. is the elongated loop-shaped amphid with nearly equal parallel limbs and prominent narrow longitudinal alae; and cephalated spicules without a gubernaculum. The diagnosis of the genus Campylaimus is emended and an identification key to species, based mainly on form and length of amphidial fovea, width of lateral alae, and copulatory apparatus is given. The genus Campylaimus now includes nineteen valid species. Two species are considered as species inquirendae, mainly because of incomplete descriptions.

Functional specialization and ontogenetic scaling of limb anatomy in Alligator mississippiensis

PubMed Central

Allen, Vivian; Elsey, Ruth M; Jones, Nicola; Wright, Jordon; Hutchinson, John R

2010-01-01

Crocodylians exhibit a fascinating diversity of terrestrial gaits and limb motions that remain poorly described and are of great importance to understanding their natural history and evolution. Their musculoskeletal anatomy is pivotal to this diversity and yet only qualitative studies of muscle-tendon unit anatomy exist. The relative masses and internal architecture (fascicle lengths and physiological cross-sectional areas) of muscles of the pectoral and pelvic limbs of American alligators (Alligator mississippiensis Daudin 1801) were recorded for an ontogenetic series of wild specimens (n = 15, body masses from 0.5 to 60 kg). The data were analysed by reduced major axis regression to determine scaling relationships with body mass. Physiological cross-sectional areas and therefore muscle force-generating capacity were found to be greater in the extensor (anti-gravity) muscles of the pelvic limb than in the pectoral limb, reflecting how crocodylians differ from mammals in having greater loading of the hindlimbs than the forelimbs. Muscle masses and architecture were generally found to scale isometrically with body mass, suggesting an ontogenetic decrease in terrestrial athleticism. This concurs with the findings of previous studies showing ontogenetic decreases in limb bone length and the general scaling principle of a decline of strength : weight ratios with increasing size in animals. Exceptions to isometric scaling found included positive allometry in fascicle length for extensor musculature of both limbs, suggesting an ontogenetic increase in working range interpreted as increasing postural variability – in particular the major hip extensors – the interpretation of which is complicated by previous described ontogenetic increase of moment arms for these muscles. PMID:20148991

The role of early development in mammalian limb diversification: a descriptive comparison of early limb development between the Natal long-fingered bat (Miniopterus natalensis) and the mouse (Mus musculus).

PubMed

Hockman, Dorit; Mason, Mandy K; Jacobs, David S; Illing, Nicola

2009-04-01

Comparative embryology expands our understanding of unique limb structures, such as that found in bats. Bat forelimb digits 2 to 5 are differentially elongated and joined by webbing, while the hindlimb digits are of similar length in many species. We compare limb development between the mouse and the Natal long-fingered bat, Miniopterus natalensis, to pinpoint the stage at which their limbs begin to differ. The bat forelimb differs from the mouse at Carollia stage (CS) 14 with the appearance of the wing membrane primordia. This difference is enhanced at CS 15 with the posterior expansion of the hand plate. The bat hindlimb begins to differ from the mouse between CS 15 and 16 when the foot plate undergoes a proximal expansion resulting in digit primordia of very similar length. Our findings support recent gene expression studies, which reveal a role for early patterning in the development of the bat limb. Copyright 2009 Wiley-Liss, Inc.

Life on the rocks: habitat use drives morphological and performance evolution in lizards.

PubMed

Goodman, Brett A; Miles, Donald B; Schwarzkopf, Lin

2008-12-01

As a group, lizards occupy a vast array of habitats worldwide, yet there remain relatively few cases where habitat use (ecology), morphology, and thus, performance, are clearly related. The best known examples include: increased limb length in response to increased arboreal perch diameter in anoles and increased limb length in response to increased habitat openness for some skinks. Rocky habitats impose strong natural selection on specific morphological characteristics, which differs from that imposed on terrestrial species, because moving about on inclined substrates of irregular sizes and shapes constrains locomotor performance in predictable ways. We quantified habitat use, morphology, and performance of 19 species of lizards (family Scincidae, subfamily Lygosominae) from 23 populations in tropical Australia. These species use habitats with considerable variation in rock availability. Comparative phylogenetic analyses revealed that occupation of rock-dominated habitats correlated with the evolution of increased limb length, compared to species from forest habitats that predominantly occupied leaf litter. Moreover, increased limb length directly affected performance, with species from rocky habitats having greater sprinting, climbing, and clinging ability than their relatives from less rocky habitats. Thus, we found that the degree of rock use is correlated with both morphological and performance evolution in this group of tropical lizards.

Upper and Lower Limb Muscle Architecture of a 104 Year-Old Cadaver

PubMed Central

Infantolino, Benjamin

2016-01-01

Muscle architecture is an important component to typical musculoskeletal models. Previous studies of human muscle architecture have focused on a single joint, two adjacent joints, or an entire limb. To date, no study has presented muscle architecture for the upper and lower limbs of a single cadaver. Additionally, muscle architectural parameters from elderly cadavers are lacking, making it difficult to accurately model elderly populations. Therefore, the purpose of this study was to present muscle architecture of the upper and lower limbs of a 104 year old female cadaver. The major muscles of the upper and lower limbs were removed and the musculotendon mass, tendon mass, musculotendon length, tendon length, pennation angle, optimal fascicle length, physiological cross-sectional area, and tendon cross-sectional area were determined for each muscle. Data from this complete cadaver are presented in table format. The data from this study can be used to construct a musculoskeletal model of a specific individual who was ambulatory, something which has not been possible to date. This should increase the accuracy of the model output as the model will be representing a specific individual, not a synthesis of measurements from multiple individuals. Additionally, an elderly individual can be modeled which will provide insight into muscle function as we age. PMID:28033339

Upper and Lower Limb Muscle Architecture of a 104 Year-Old Cadaver.

PubMed

Ruggiero, Marissa; Cless, Daniel; Infantolino, Benjamin

2016-01-01

Muscle architecture is an important component to typical musculoskeletal models. Previous studies of human muscle architecture have focused on a single joint, two adjacent joints, or an entire limb. To date, no study has presented muscle architecture for the upper and lower limbs of a single cadaver. Additionally, muscle architectural parameters from elderly cadavers are lacking, making it difficult to accurately model elderly populations. Therefore, the purpose of this study was to present muscle architecture of the upper and lower limbs of a 104 year old female cadaver. The major muscles of the upper and lower limbs were removed and the musculotendon mass, tendon mass, musculotendon length, tendon length, pennation angle, optimal fascicle length, physiological cross-sectional area, and tendon cross-sectional area were determined for each muscle. Data from this complete cadaver are presented in table format. The data from this study can be used to construct a musculoskeletal model of a specific individual who was ambulatory, something which has not been possible to date. This should increase the accuracy of the model output as the model will be representing a specific individual, not a synthesis of measurements from multiple individuals. Additionally, an elderly individual can be modeled which will provide insight into muscle function as we age.

Functional anatomy and muscle moment arms of the pelvic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris)

PubMed Central

Williams, S B; Wilson, A M; Rhodes, L; Andrews, J; Payne, R C

2008-01-01

We provide quantitative anatomical data on the muscle–tendon architecture and geometry of the pelvic limb of an elite sprint athlete, the racing greyhound. Specifically, muscle masses, muscle lengths, fascicle lengths, pennation angles and muscle moment arms were measured. Maximum isometric force and power of muscles, the maximum muscle torque at joints and tendon stress and strain were estimated. We compare data with that published for a generalized breed of canid, and other cursorial mammals such as the horse and hare. The pelvic limb of the racing greyhound had a relatively large volume of hip extensor muscle, which is likely to be required for power production. Per unit body mass, some pelvic limb muscles were relatively larger than those in less specialized canines, and many hip extensor muscles had longer fascicle lengths. It was estimated that substantial extensor moments could be created about the tarsus and hip of the greyhound allowing high power output and potential for rapid acceleration. The racing greyhound hence possesses substantial specializations for enhanced sprint performance. PMID:18657259

Functional anatomy and muscle moment arms of the pelvic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris).

PubMed

Williams, S B; Wilson, A M; Rhodes, L; Andrews, J; Payne, R C

2008-10-01

We provide quantitative anatomical data on the muscle-tendon architecture and geometry of the pelvic limb of an elite sprint athlete, the racing greyhound. Specifically, muscle masses, muscle lengths, fascicle lengths, pennation angles and muscle moment arms were measured. Maximum isometric force and power of muscles, the maximum muscle torque at joints and tendon stress and strain were estimated. We compare data with that published for a generalized breed of canid, and other cursorial mammals such as the horse and hare. The pelvic limb of the racing greyhound had a relatively large volume of hip extensor muscle, which is likely to be required for power production. Per unit body mass, some pelvic limb muscles were relatively larger than those in less specialized canines, and many hip extensor muscles had longer fascicle lengths. It was estimated that substantial extensor moments could be created about the tarsus and hip of the greyhound allowing high power output and potential for rapid acceleration. The racing greyhound hence possesses substantial specializations for enhanced sprint performance.

Lower limb muscle volume estimation from maximum cross-sectional area and muscle length in cerebral palsy and typically developing individuals.

PubMed

Vanmechelen, Inti M; Shortland, Adam P; Noble, Jonathan J

2018-01-01

Deficits in muscle volume may be a significant contributor to physical disability in young people with cerebral palsy. However, 3D measurements of muscle volume using MRI or 3D ultrasound may be difficult to make routinely in the clinic. We wished to establish whether accurate estimates of muscle volume could be made from a combination of anatomical cross-sectional area and length measurements in samples of typically developing young people and young people with bilateral cerebral palsy. Lower limb MRI scans were obtained from the lower limbs of 21 individuals with cerebral palsy (14.7±3years, 17 male) and 23 typically developing individuals (16.8±3.3years, 16 male). The volume, length and anatomical cross-sectional area were estimated from six muscles of the left lower limb. Analysis of Covariance demonstrated that the relationship between the length*cross-sectional area and volume was not significantly different depending on the subject group. Linear regression analysis demonstrated that the product of anatomical cross-sectional area and length bore a strong and significant relationship to the measured muscle volume (R 2 values between 0.955 and 0.988) with low standard error of the estimates of 4.8 to 8.9%. This study demonstrates that muscle volume may be estimated accurately in typically developing individuals and individuals with cerebral palsy by a combination of anatomical cross-sectional area and muscle length. 2D ultrasound may be a convenient method of making these measurements routinely in the clinic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cost and quality implications of discrepancies between admitting and discharge diagnoses.

PubMed

McNutt, Robert; Johnson, Tricia; Kane, Jason; Ackerman, Mariel; Odwazny, Richard; Bardhan, Jaydeep

2012-01-01

Presenting and discharge diagnoses of hospitalized patients may differ as a result of patient complexity, diagnostic dilemmas, or errors in clinical judgment at the time of primary assessment. When diagnoses at admission and discharge are not in agreement, this discrepancy may indicate more complex processes of care and resultant costs. It is unclear whether surrogate measures reflecting quality of care are impacted by discrepant diagnoses. To assess whether an association exists between admitting and discharge International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes and other quality markers including hospital length of stay, total cost of care, and 30-day readmission rate. This was a retrospective, cross-sectional analysis of general internal medicine patients aged 18 years and older. Diagnosis discrepancy was defined as a difference between the 3-digit ICD-9 diagnosis code at admission and the principal 3-digit ICD-9 diagnosis code at discharge. Sixty-eight percent of patients had a diagnosis discrepancy. Diagnosis discrepancy was associated with a 0.41-day increase in length of stay (P < .001), $663 increase in direct costs (P < .001), and a 1.55 times greater odds of readmission within 30 days (P < .001). Diagnosis discrepancy was associated with hospital quality outcome measures. This finding likely reflects variations in patients' diagnostic complexity.

Biochemical adaptations of antigravity muscle fibers to disuse atrophy

NASA Technical Reports Server (NTRS)

Booth, F. W.

1978-01-01

Studies are presented in four parts of this report. The four parts include; (1) studies to gain information on the molecular basis of atrophy by antigravity muscle; (2) studies on the work capacity of antigravity muscles during atrophy and during recovery from atrophy; (3) studies on recovery of degenerated antigravity fibers after removal of hind-limb casts; and (4) studies on the atrophy and recovery of bone. The philosophy of these studies was to identify the time sequence of events in the soleus muscle of the rat following immobilization of the hind limbs, so that the length of the soleus muscle within the fixed limb is less than its resting length. In two separate studies, no decline in the weight of the soleus muscle could be detected during the first 72 hours of limb immobilization.

A Simple Technique for Jejunojejunal Revision in Laparoscopic Roux-en-Y Gastric Bypass.

PubMed

Spivak, Hadar

2015-12-01

The lengths of the bypassed segments in the initial laparoscopic roux-en-Y gastric bypass (LRYGB) are usually a matter of the individual surgeon's routine. The literature is inconclusive about the association between the Roux limbs' length and weight-loss or malabsorption (Stefanidis et al. Obes Surg. 21(1):119-24, 2011); (Rawlins et al. Surg Obes Relat Dis. 7(1):45-9, 2011). However, jejunojejunal anastomosis (JJ) "redo" and Roux limb length revision could be considered for patients with a very short Roux limb and weight loss failure or for short common channel and malabsorption. Complications of JJ may also require revision. In over 1000 LRYGBs since 2001, eight patients required JJ revision for failure to lose enough weight (n = 6), malabsorption (n = 1), and stricture (n = 1). Instead of completely taking down the JJ, a simple technique was evolved to keep the enteric limb continuity. In a following step, the biliopancreatic limbs have been transected from the JJ and reconnected proximal (for malabsorption) or distal (for weight loss failure). In this video, a step-by-step the laparoscopic technique for JJ revision and relocating the biliopancreatic limb is presented. Procedure takes 40-60 min to perform using four trocars and the hospital stay was 1-2 nights. No complications occurred during the procedures or postoperative period. Laparoscopic revision of JJ is feasible and safe and should be part of surgeons' options on the long-term management of patients post LRYGB.

Carbachol-induced volume adaptation in mouse bladder and length adaptation via rhythmic contraction in rabbit detrusor.

PubMed

Speich, John E; Wilson, Cameron W; Almasri, Atheer M; Southern, Jordan B; Klausner, Adam P; Ratz, Paul H

2012-10-01

The length-tension (L-T) relationships in rabbit detrusor smooth muscle (DSM) are similar to those in vascular and airway smooth muscles and exhibit short-term length adaptation characterized by L-T curves that shift along the length axis as a function of activation and strain history. In contrast to skeletal muscle, the length-active tension (L-T(a)) curve for rabbit DSM strips does not have a unique peak tension value with a single ascending and descending limb. Instead, DSM can exhibit multiple ascending and descending limbs, and repeated KCl-induced contractions at a particular muscle length on an ascending or descending limb display increasingly greater tension. In the present study, mouse bladder strips with and without urothelium exhibited KCl-induced and carbachol-induced length adaptation, and the pressure-volume relationship in mouse whole bladder displayed short-term volume adaptation. Finally, prostaglandin-E(2)-induced low-level rhythmic contraction produced length adaptation in rabbit DSM strips. A likely role of length adaptation during bladder filling is to prepare DSM cells to contract efficiently over a broad range of volumes. Mammalian bladders exhibit spontaneous rhythmic contraction (SRC) during the filling phase and SRC is elevated in humans with overactive bladder (OAB). The present data identify a potential physiological role for SRC in bladder adaptation and motivate the investigation of a potential link between short-term volume adaptation and OAB with impaired contractility.

Numerical analysis of finite Debye-length effects in induced-charge electro-osmosis.

PubMed

Gregersen, Misha Marie; Andersen, Mathias Baekbo; Soni, Gaurav; Meinhart, Carl; Bruus, Henrik

2009-06-01

For a microchamber filled with a binary electrolyte and containing a flat unbiased center electrode at one wall, we employ three numerical models to study the strength of the resulting induced-charge electro-osmotic (ICEO) flow rolls: (i) a full nonlinear continuum model resolving the double layer, (ii) a linear slip-velocity model not resolving the double layer and without tangential charge transport inside this layer, and (iii) a nonlinear slip-velocity model extending the linear model by including the tangential charge transport inside the double layer. We show that, compared to the full model, the slip-velocity models significantly overestimate the ICEO flow. This provides a partial explanation of the quantitative discrepancy between observed and calculated ICEO velocities reported in the literature. The discrepancy increases significantly for increasing Debye length relative to the electrode size, i.e., for nanofluidic systems. However, even for electrode dimensions in the micrometer range, the discrepancies in velocity due to the finite Debye length can be more than 10% for an electrode of zero height and more than 100% for electrode heights comparable to the Debye length.

Perception of Saudi dentists and lay people to altered smile esthetics.

PubMed

Talic, Nabeel; Alomar, Samar; Almaidhan, Asma

2013-01-01

To evaluate and compare the perceptions of Saudi dentists and lay people to altered smile features. Thirty-six digital smile photographs with altered features were used. Altered features included the following: crown length, width, gingival level of the lateral incisors, gingival display, midline diastema, and upper midline shift. The photographs were presented to a sample of 30 dentists and 30 lay people with equal gender distribution. Each participant rated each picture with a visual analogue scale, which ranged from 0 (very unattractive) to 100 (very attractive). Dentists were more critical than lay people when evaluating symmetrical crown length discrepancies. Compared to lay people, Saudi dentists gave lower ratings to a crown length discrepancy of >2 mm (P < 0.001), crown width discrepancy of ⩾2 mm (P < 0.05), change in gingiva to lip distance of ⩾2 mm (P < 0.01), and midline deviation of >1 mm (P < 0.01). There was no significant difference between dentists and lay people towards alterations in the gingival level of the lateral incisors or towards a space between the central incisors. No significant sex difference was seen across the groups. In this sample, Saudi dentists gave significantly lower attractiveness scores to crown length and crown width discrepancies, midline deviations, and changes in gingiva to lip distance compared to Saudi lay people.

Tooth-size discrepancy: A comparison between manual and digital methods

PubMed Central

Correia, Gabriele Dória Cabral; Habib, Fernando Antonio Lima; Vogel, Carlos Jorge

2014-01-01

Introduction Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models. Objective This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models. Material and Methods To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas. Results Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference. Conclusions Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable. PMID:25279529

Genetic regulation of canine skeletal traits: trade-offs between the hind limbs and forelimbs in the fox and dog

PubMed Central

Kharlamova, Anastasia V.; Trut, Lyudmila N.; Carrier, David R.; Chase, Kevin; Lark, Karl G.

2008-01-01

Synopsis Genetic variation in functionally integrated skeletal traits can be maintained over 10 million years despite bottlenecks and stringent selection. Here, we describe an analysis of the genetic architecture of the canid axial skeleton using populations of the Portuguese Water Dog Canis familiaris) and silver fox (Vulpes vulpes). Twenty-one skeletal metrics taken from radiographs of the forelimbs and hind limbs of the fox and dog were used to construct separate anatomical principal component (PC) matrices of the two species. In both species, 15 of the 21 PCs exhibited significant heritability, ranging from 25% to 70%. The second PC, in both species, represents a trade-off in which limb-bone width is inversely correlated with limb-bone length. PC2 accounts for approximately 15% of the observed skeletal variation, ~30% of the variation in shape. Many of the other significant PCs affect very small amounts of variation (e.g., 0.2–2%) along trade-off axes that partition function between the forelimbs and hind limbs. These PCs represent shape axes in which an increase in size of an element of the forelimb is associated with a decrease in size of an element of the hind limb and vice versa. In most cases, these trade-offs are heritable in both species and genetic loci have been identified in the Portuguese Water Dog for many of these. These PCs, present in both the dog and the fox, include ones that affect lengths of the forelimb versus the hind limb, length of the forefoot versus that of the hind foot, muscle moment (i.e., lever) arms of the forelimb versus hind limb, and cortical thickness of the bones of the forelimb versus hind limb. These inverse relationships suggest that genetic regulation of the axial skeleton results, in part, from the action of genes that influence suites of functionally integrated traits. Their presence in both dogs and foxes suggests that the genes controlling the regulation of these PCs of the forelimb versus hind limb may be found in other tetrapod taxa. PMID:18458753

Comparative architectural properties of limb muscles in Crocodylidae and Alligatoridae and their relevance to divergent use of asymmetrical gaits in extant Crocodylia.

PubMed

Allen, Vivian; Molnar, Julia; Parker, William; Pollard, Andrea; Nolan, Grant; Hutchinson, John R

2014-12-01

Crocodiles and their kin (Crocodylidae) use asymmetrical (bounding and galloping) gaits when moving rapidly. Despite being morphologically and ecologically similar, it seems alligators and their kin (Alligatoridae) do not. To investigate a possible anatomical basis for this apparent major difference in locomotor capabilities, we measured relative masses and internal architecture (fascicle lengths and physiological cross-sectional areas) of muscles of the pectoral and pelvic limbs of 40 individuals from six representative species of Crocodylidae and Alligatoridae. We found that, relative to body mass, Crocodylidae have significantly longer muscle fascicles (increased working range), particularly in the pectoral limb, and generally smaller muscle physiological cross-sectional areas (decreased force-exerting capability) than Alligatoridae. We therefore hypothesise that the ability of some crocodylians to use asymmetrical gaits may be limited more by the ability to make large, rapid limb motions (especially in the pectoral limb) than the ability to exert large limb forces. Furthermore, analysis of scaling patterns in muscle properties shows that limb anatomy in the two clades becomes more divergent during ontogeny. Limb muscle masses, fascicle lengths and physiological cross-sectional areas scale with significantly larger coefficients in Crocodylidae than Alligatoridae. This combination of factors suggests that inter-clade disparity in maximal limb power is highest in adult animals. Therefore, despite their apparent morphological similarities, both mean values and scaling patterns suggest that considerable diversity exists in the locomotor apparatus of extant Crocodylia. © 2014 Anatomical Society.

Optimal Body Size and Limb Length Ratios Associated with 100-m Personal-Best Swim Speeds.

PubMed

Nevill, Alan M; Oxford, Samuel W; Duncan, Michael J

2015-08-01

This study aims to identify optimal body size and limb segment length ratios associated with 100-m personal-best (PB) swim speeds in children and adolescents. Fifty national-standard youth swimmers (21 males and 29 females age 11-16 yr; mean ± SD age, 13.5 ± 1.5 yr) participated in the study. Anthropometry comprised stature; body mass; skinfolds; maturity offset; upper arm, lower arm, and hand lengths; and upper leg, lower leg, and foot lengths. Swimming performance was taken as the PB time recorded in competition for the 100-m freestyle swim. To identify the optimal body size and body composition components associated with 100-m PB swim speeds (having controlled for age and maturity offset), we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. Lean body mass was the singularly most important whole-body characteristic. Stature and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. The allometric model also identified that having greater limb segment length ratios [i.e., arm ratio = (low arm)/(upper arm); foot-to-leg ratio = (foot)/(lower leg)] was key to PB swim speeds. It is only by adopting multiplicative allometric models that the above mentioned ratios could have been derived. The advantage of having a greater lower arm is clear; however, having a shorter upper arm (achieved by adopting a closer elbow angle technique or by possessing a naturally endowed shorter upper arm), at the same time, is a new insight into swimming performance. A greater foot-to-lower-leg ratio suggests that a combination of larger feet and shorter lower leg length may also benefit PB swim speeds.

Sizing the Jurassic theropod dinosaur Allosaurus: assessing growth strategy and evolution of ontogenetic scaling of limbs.

PubMed

Bybee, Paul J; Lee, Andrew H; Lamm, Ellen-Thérèse

2006-03-01

Allosaurus is one of the most common Mesozoic theropod dinosaurs. We present a histological analysis to assess its growth strategy and ontogenetic limb bone scaling. Based on an ontogenetic series of humeral, ulnar, femoral, and tibial sections of fibrolamellar bone, we estimate the ages of the largest individuals in the sample to be between 13-19 years. Growth curve reconstruction suggests that maximum growth occurred at 15 years, when body mass increased 148 kg/year. Based on larger bones of Allosaurus, we estimate an upper age limit of between 22-28 years of age, which is similar to preliminary data for other large theropods. Both Model I and Model II regression analyses suggest that relative to the length of the femur, the lengths of the humerus, ulna, and tibia increase in length more slowly than isometry predicts. That pattern of limb scaling in Allosaurus is similar to those in other large theropods such as the tyrannosaurids. Phylogenetic optimization suggests that large theropods independently evolved reduced humeral, ulnar, and tibial lengths by a phyletic reduction in longitudinal growth relative to the femur.

Influences of the extensor portion of the gluteus maximus muscle on pelvic tilt before and after the performance of a fatigue protocol.

PubMed

Alvim, Felipe C; Peixoto, Jennifer G; Vicente, Eduardo J D; Chagas, Paula S C; Fonseca, Diogo S

2010-01-01

There is a lack of data in the literature for determining the influences of the extensor portion of the gluteus maximus muscle on pelvic tilting and, thus, on lumbar stability. To assess the influences of the extensor portion of the gluteus maximus muscle on pelvic tilt. Ten healthy young subjects were recruited, with a body mass index (BMI) below 24.9 kg/m(2) and leg length discrepancy below 1 cm. The BMI, pelvic perimeter and lower-limb lengths were assessed and, subsequently, the degrees of hemi-pelvic tilt and asymmetry between them were analyzed using lateral view photographs of the subjects in a standing position, using SAPO (Software for Postural Assessment). Next, fatigue was induced in the extensor portion of the gluteus maximus muscle on the dominant side, and after that the hemi-pelvic tilt and the asymmetry between the hemi-pelvises were reassessed. The Pearson r and Student t tests were conducted at the significance level of alpha=0.05. There were no significant correlations between the confounding variables and asymmetry of the hemi-pelvic angles. There were significant changes in the hemi-pelvic angle of the dominant side (t=3.760; p=0.004). Fatigue in the extensor portion of the gluteus maximus muscle can generate increases in the tilt angle of the ipsilateral pelvis.

A comparative study of single-leg ground reaction forces in running lizards.

PubMed

McElroy, Eric J; Wilson, Robbie; Biknevicius, Audrone R; Reilly, Stephen M

2014-03-01

The role of different limbs in supporting and propelling the body has been studied in many species with animals appearing to have either similarity in limb function or differential limb function. Differential hindlimb versus forelimb function has been proposed as a general feature of running with a sprawling posture and as benefiting sprawled postured animals by enhancing maneuvering and minimizing joint moments. Yet only a few species have been studied and thus the generality of differential limb function in running animals with sprawled postures is unknown. We measured the limb lengths of seven species of lizard and their single-limb three-dimensional ground reaction forces during high-speed running. We found that all species relied on the hindlimb for producing accelerative forces. Braking forces were forelimb dominated in four species and equally distributed between limbs in the other three. Vertical forces were dominated by the hindlimb in three species and equally distributed between the forelimb and hindlimb in the other four. Medial forces were dominated by the hindlimb in four species and equally distributed in the other three, with all Iguanians exhibiting hindlimb-biased medial forces. Relative hindlimb to forelimb length of each species was related to variation in hindlimb versus forelimb medial forces; species with relatively longer hindlimbs compared with forelimbs exhibited medial forces that were more biased towards the hindlimbs. These results suggest that the function of individual limbs in lizards varies across species with only a single general pattern (hindlimb-dominated accelerative force) being present.

Percutaneous epiphysiodesis using transphyseal screws (PETS): prospective case study and review.

PubMed

Nouth, Fred; Kuo, Leonard A

2004-01-01

Percutaneous epiphysiodesis using transphyseal screws (PETS) is a relatively new procedure being used for the correction of moderate leg length discrepancy and angular deformities in children. Over a mean follow-up of 2.4 years the authors followed prospectively 18 patients who underwent PETS. Nine had correction of angular deformity and nine had leg length inequality. The average reduction in leg length discrepancy was from 3.33 to 1.36 cm. The average improvement in angular deformity was 69%. This quick, minimally invasive, and potentially reversible procedure has the added benefits of a short hospital stay with low morbidity, making it a suitable alternative to the more traditional methods of epiphysiodesis.

Decreasing initial telomere length in humans intergenerationally understates age-associated telomere shortening

PubMed Central

Holohan, Brody; De Meyer, Tim; Batten, Kimberly; Mangino, Massimo; Hunt, Steven C; Bekaert, Sofie; De Buyzere, Marc L; Rietzschel, Ernst R; Spector, Tim D; Wright, Woodring E; Shay, Jerry W

2015-01-01

Telomere length shortens with aging, and short telomeres have been linked to a wide variety of pathologies. Previous studies suggested a discrepancy in age-associated telomere shortening rate estimated by cross-sectional studies versus the rate measured in longitudinal studies, indicating a potential bias in cross-sectional estimates. Intergenerational changes in initial telomere length, such as that predicted by the previously described effect of a father’s age at birth of his offspring (FAB), could explain the discrepancy in shortening rate measurements. We evaluated whether changes occur in initial telomere length over multiple generations in three large datasets and identified paternal birth year (PBY) as a variable that reconciles the difference between longitudinal and cross-sectional measurements. We also clarify the association between FAB and offspring telomere length, demonstrating that this effect is substantially larger than reported in the past. These results indicate the presence of a downward secular trend in telomere length at birth over generational time with potential public health implications. PMID:25952108

Dimensional Characteristics of Hardwood Top and Limb Residue

Treesearch

Nels S. Christopherson

1983-01-01

Sawtimber harvesting in northern hardwood stands leaves behind a large amount of residue in the form of tops and limbs. This paper presents typical dimensional characteristics of residue for northern hardwood tops incluting data on lengths, widths, diameters, and complete branch details.

Age-related changes in spatiotemporal characteristics of gait accompany ongoing lower limb linear growth in late childhood and early adolescence.

PubMed

Froehle, Andrew W; Nahhas, Ramzi W; Sherwood, Richard J; Duren, Dana L

2013-05-01

Walking gait is generally held to reach maturity, including walking at adult-like velocities, by 7-8 years of age. Lower limb length, however, is a major determinant of gait, and continues to increase until 13-15 years of age. This study used a sample from the Fels Longitudinal Study (ages 8-30 years) to test the hypothesis that walking with adult-like velocity on immature lower limbs results in the retention of immature gait characteristics during late childhood and early adolescence. There was no relationship between walking velocity and age in this sample, whereas the lower limb continued to grow, reaching maturity at 13.2 years in females and 15.6 years in males. Piecewise linear mixed models regression analysis revealed significant age-related trends in normalized cadence, initial double support time, single support time, base of support, and normalized step length in both sexes. Each trend reached its own, variable-specific age at maturity, after which the gait variables' relationships with age reached plateaus and did not differ significantly from zero. Offsets in ages at maturity occurred among the gait variables, and between the gait variables and lower limb length. The sexes also differed in their patterns of maturation. Generally, however, immature walkers of both sexes took more frequent and relatively longer steps than did mature walkers. These results support the hypothesis that maturational changes in gait accompany ongoing lower limb growth, with implications for diagnosing, preventing, and treating movement-related disorders and injuries during late childhood and early adolescence. Copyright © 2012 Elsevier B.V. All rights reserved.

Popcorn calcification in osteogenesis imperfecta: incidence, progression, and molecular correlation.

PubMed

Obafemi, Abimbola A; Bulas, Dorothy I; Troendle, James; Marini, Joan C

2008-11-01

Osteogenesis imperfecta (OI) is a heritable disorder characterized by osteoporosis and increased susceptibility to fracture. All children with severe OI have extreme short stature and some have "popcorn" calcifications, areas of disorganized hyperdense lines in the metaphysis and epiphysis around the growth plate on lower limb radiographs. Popcorn calcifications were noted on radiographs of two children with non-lethal type VIII OI, a recessive form caused by P3H1 deficiency. To determine the incidence, progression, and molecular correlations of popcorn calcifications, we retrospectively examined serial lower limb radiographs of 45 children with type III or IV OI and known dominant mutations in type I collagen. Popcorn calcifications were present in 13 of 25 type III (52%), but only 2 of 20 type IV (10%), OI children. The mean age of onset was 7.0 years, with a range of 4-14 years. All children with popcorn calcifications had this finding in their distal femora, and most also had calcifications in proximal tibiae. While unilateral popcorn calcification contributes to femoral growth deficiency and leg length discrepancy, severe linear growth deficiency, and metaphyseal flare do not differ significantly between type III OI patients with and without popcorn calcifications. The type I collagen mutations associated with popcorn calcifications occur equally in both COL1A1 and COL1A2, and have no preferential location along the chains. These data demonstrate that popcorn calcifications are a frequent feature of severe OI, but do not distinguish cases with defects in collagen structure (primarily dominant type III OI) or modification (recessive type VIII OI). Copyright 2008 Wiley-Liss, Inc.

Whole-bone scaling of the avian pelvic limb.

PubMed

Doube, Michael; Yen, Stephanie C W; Kłosowski, Michał M; Farke, Andrew A; Hutchinson, John R; Shefelbine, Sandra J

2012-07-01

Birds form the largest extant group of bipedal animals and occupy a broad range of body masses, from grams to hundreds of kilograms. Additionally, birds occupy distinct niches of locomotor behaviour, from totally flightless strong runners such as the ratites (moa, kiwi, ostrich) to birds that may walk, dabble on water or fly. We apply a whole-bone approach to investigate allometric scaling trends in the pelvic limb bones (femur, tibiotarsus, tarsometatarsus) from extant and recently extinct birds of greatly different size, and compare scaling between birds in four locomotor groups; flightless, burst-flying, dabbling and flying. We also compare scaling of birds' femoral cross-sectional properties to data previously collected from cats. Scaling exponents were not significantly different between the different locomotor style groups, but elevations of the scaling relationships revealed that dabblers (ducks, geese, swans) have particularly short and slender femora compared with other birds of similar body mass. In common with cats, but less pronounced in birds, the proximal and distal extrema of the bones scaled more strongly than the diaphysis, and in larger birds the diaphysis occupied a smaller proportion of bone length than in smaller birds. Cats and birds have similar femoral cross-sectional area (CSA) for the same body mass, yet birds' bone material is located further from the bone's long axis, leading to higher second and polar moments of area and a greater inferred resistance to bending and twisting. The discrepancy in the relationship between outer diameter to CSA may underlie birds' reputation for having 'light' bones. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

Whole-bone scaling of the avian pelvic limb

PubMed Central

Doube, Michael; Yen, Stephanie C W; Kłosowski, Michał M; Farke, Andrew A; Hutchinson, John R; Shefelbine, Sandra J

2012-01-01

Birds form the largest extant group of bipedal animals and occupy a broad range of body masses, from grams to hundreds of kilograms. Additionally, birds occupy distinct niches of locomotor behaviour, from totally flightless strong runners such as the ratites (moa, kiwi, ostrich) to birds that may walk, dabble on water or fly. We apply a whole-bone approach to investigate allometric scaling trends in the pelvic limb bones (femur, tibiotarsus, tarsometatarsus) from extant and recently extinct birds of greatly different size, and compare scaling between birds in four locomotor groups; flightless, burst-flying, dabbling and flying. We also compare scaling of birds’ femoral cross-sectional properties to data previously collected from cats. Scaling exponents were not significantly different between the different locomotor style groups, but elevations of the scaling relationships revealed that dabblers (ducks, geese, swans) have particularly short and slender femora compared with other birds of similar body mass. In common with cats, but less pronounced in birds, the proximal and distal extrema of the bones scaled more strongly than the diaphysis, and in larger birds the diaphysis occupied a smaller proportion of bone length than in smaller birds. Cats and birds have similar femoral cross-sectional area (CSA) for the same body mass, yet birds’ bone material is located further from the bone’s long axis, leading to higher second and polar moments of area and a greater inferred resistance to bending and twisting. The discrepancy in the relationship between outer diameter to CSA may underlie birds’ reputation for having ‘light’ bones. PMID:22606941

Method and apparatus for simulating gravitational forces on a living organism

NASA Technical Reports Server (NTRS)

Thornton, W. E. (Inventor)

1983-01-01

A method and apparatus for simulating gravitational forces on a living organism wherein a series of negative pressures are externally applied to successive length-wise sections of a lower limb of the organism. The pressures decreasing progressively with distance of said limb sections from the heart of the organism. A casing defines a chamber adapted to contain the limb of the organism and is rigidified to resist collapse upon the application of negative pressures to the interior of the chamber. Seals extend inwardly from the casing for effective engagement with the limb of the organism and, in cooperation with the limb, subdivide the chamber into a plurality of compartments each in negative pressure communicating relation with the limb.

Optimal Roux-en-Y reconstruction after distal gastrectomy for early gastric cancer as assessed using the newly developed PGSAS-45 scale.

PubMed

Kawahira, Hiroshi; Kodera, Yasuhiro; Hiki, Naoki; Takahashi, Masazumi; Itoh, Seiji; Mitsumori, Norio; Kawashima, Yoshiyuki; Namikawa, Tsutomu; Inada, Takao; Nakada, Koji

2015-10-01

The optimal surgical procedure for distal gastrectomy with Roux-en-Y reconstruction (DGRY) remains to be determined. Recently, a self-report assessment instrument, the Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45), was compiled to evaluate symptoms, the living status and the quality of life of patients who have undergone gastrectomy. We used this scale to evaluate procedures used for DGRY. The subjects included 475 patients who underwent DGRY for stage IA/IB gastric cancer. We evaluated whether the size of the remnant stomach, length of the Roux limb, reconstruction route and anastomotic procedure affected the patients' symptoms, living status and quality of life assessed using the PGSAS-45. Patients with a residual stomach of more than half had significantly worse esophageal reflux scores than the patients with a smaller residual stomach (P = 0.0462); a residual stomach of one-third or one-fourth was favorable. A shorter length of the Roux limb was shown to be preferable to a longer Roux limb based on the results of the PGSAS-45. In addition, antecolic reconstruction and the anastomotic procedure using a linear stapler were found to be more favorable. The size of the remnant stomach and the length and route of the Roux limb significantly influence the patient-reported DGRY outcomes.

Comparative anatomy and muscle architecture of selected hind limb muscles in the Quarter Horse and Arab.

PubMed

Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wakeling, J M; Wilson, A M; Payne, R C

2008-02-01

The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tibialis cranialis and extensor digitorum longus. Specifically, muscle mass, fascicle length and pennation angle were quantified and physiological cross-sectional area (PCSA) and maximum isometric force were estimated. The hind limb muscles of the Quarter Horse were of a significantly greater mass, but had similar fascicle lengths and pennation angles when compared with those of the Arab; this resulted in the Quarter Horse hind limb muscles having greater PCSAs and hence greater isometric force potential. This study suggests that Quarter Horses as a breed inherently possess large strong hind limb muscles, with the potential to accelerate their body mass more rapidly than those of the Arab.

The Ergogenic Effect of Elastic Therapeutic Tape on Stride and Step Length in Fatigued Runners

PubMed Central

Ward, John; Sorrels, Kenneth; Coats, Jesse; Pourmoghaddam, Amir; Moskop, JoAnn; Ueckert, Kate; Glass, Amanda

2014-01-01

Objective The purpose of this study was to determine if elastic therapeutic tape placed on anterior lower limbs would affect stride and step length in fatigued runners’ gait. Methods Forty-two healthy participants were equally divided into a kinesiology tape group (Rocktape) and a no-tape control group. Participants in both groups underwent a baseline running gait test at 6 mph without tape. After this, participants engaged in an exhaustive lower body fatigue protocol until they reached maximal volitional exhaustion. Participants were then randomized to 1 of 2 interventions: (1) Experimental group, which had kinesiology tape placed under tension on the anterior aspect of their lower limbs bilaterally from the upper thigh to just below the patella, or (2) Control group, which did not receive taping. All participants then engaged in a similar 6-mph running gait postanalysis. Participant’s gait was analyzed for 90 seconds during each test iteration. Researchers used a 2-way repeated-measures analysis of variance considering fatigue (prefatigue, postfatigue) and group (tape, no-tape) as subject factors. Results After the fatigue protocol, the no-tape group demonstrated a significant decrease in step length of 14.2 mm (P = .041) and stride length of 29.4 mm (P = .043). The kinesiology tape group did not demonstrate a significant decline in these gait parameters. Conclusions In this preliminary study, placing elastic therapeutic tape over the anterior lower limbs demonstrated short-term preservation of runner step length and stride length in a fatigued state. PMID:25435835

Efficacy of a hybrid assistive limb in post-stroke hemiplegic patients: a preliminary report

PubMed Central

2011-01-01

Background Robotic devices are expected to be widely used in various applications including support for the independent mobility of the elderly with muscle weakness and people with impaired motor function as well as support for nursing care that involves heavy laborious work. We evaluated the effects of a hybrid assistive limb robot suit on the gait of stroke patients undergoing rehabilitation. Methods The study group comprised 16 stroke patients with severe hemiplegia. All patients underwent gait training. Four patients required assistance, and 12 needed supervision while walking. The stride length, walking speed and physiological cost index on wearing the hybrid assistive limb suit and a knee-ankle-foot orthosis were compared. Results The hybrid assistive limb suit increased the stride length and walking speed in 4 of 16 patients. The patients whose walking speed decreased on wearing the hybrid assistive limb suit either had not received sufficient gait training or had an established gait pattern with a knee-ankle-foot orthosis using a quad cane. The physiological cost index increased after wearing the hybrid assistive limb suit in 12 patients, but removal of the suit led to a decrease in the physiological cost index values to equivalent levels prior to the use of the suit. Conclusions Although the hybrid assistive limb suit is not useful for all hemiplegic patients, it may increase the walking speed and affect the walking ability. Further investigation would clarify its indication for the possibility of gait training. PMID:21943320

Adaptation of the length-active tension relationship in rabbit detrusor

PubMed Central

Almasri, Atheer M.; Bhatia, Hersch; Klausner, Adam P.; Ratz, Paul H.

2009-01-01

Studies have shown that the length-tension (L-T) relationships in airway and vascular smooth muscles are dynamic and can adapt to length changes over a period of time. Our prior studies have shown that the passive L-T relationship in rabbit detrusor smooth muscle (DSM) is also dynamic and that DSM exhibits adjustable passive stiffness (APS) characterized by a passive L-T curve that can shift along the length axis as a function of strain history and activation history. The present study demonstrates that the active L-T curve for DSM is also dynamic and that the peak active tension produced at a particular muscle length is a function of both strain and activation history. More specifically, this study reveals that the active L-T relationship, or curve, does not have a unique peak tension value with a single ascending and descending limb, but instead reveals that multiple ascending and descending limbs can be exhibited in the same DSM strip. This study also demonstrates that for DSM strips not stretched far enough to reveal a descending limb, the peak active tension produced by a maximal KCl-induced contraction at a short, passively slack muscle length of 3 mm was reduced by 58.6 ± 4.1% (n = 15) following stretches to and contractions at threefold the original muscle length, 9 mm. Moreover, five subsequent contractions at the short muscle length displayed increasingly greater tension; active tension produced by the sixth contraction was 91.5 ± 9.1% of that produced by the prestretch contraction at that length. Together, these findings indicate for the first time that DSM exhibits length adaptation, similar to vascular and airway smooth muscles. In addition, our findings demonstrate that preconditioning, APS and adaptation of the active L-T curve can each impact the maximum total tension observed at a particular DSM length. PMID:19675182

100-m Breaststroke Swimming Performance in Youth Swimmers: The Predictive Value of Anthropometrics.

PubMed

Sammoud, Senda; Nevill, Alan Michael; Negra, Yassine; Bouguezzi, Raja; Chaabene, Helmi; Hachana, Younés

2018-03-16

This study aimed to estimate the optimal body size, limb segment length, and girth or breadth ratios of 100-m breaststroke performance in youth swimmers. In total, 59 swimmers [male: n = 39, age = 11.5 (1.3) y; female: n = 20, age = 12.0 (1.0) y] participated in this study. To identify size/shape characteristics associated with 100-m breaststroke swimming performance, we computed a multiplicative allometric log-linear regression model, which was refined using backward elimination. Results showed that the 100-m breaststroke performance revealed a significant negative association with fat mass and a significant positive association with the segment length ratio (arm ratio = hand length/forearm length) and limb girth ratio (girth ratio = forearm girth/wrist girth). In addition, leg length, biacromial breadth, and biiliocristal breadth revealed significant positive associations with the 100-m breaststroke performance. However, height and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. In fact, it is only by adopting multiplicative allometric models that the previously mentioned ratios could have been derived. These results highlighted the importance of considering anthropometric characteristics of youth breaststroke swimmers for talent identification and/or athlete monitoring purposes. In addition, these findings may assist orienting swimmers to the appropriate stroke based on their anthropometric characteristics.

A Special Golden Curve in Human Upper Limbs' Length Proportion: A Functional Partition Which Is Different from Anatomy.

PubMed

Wang, Nan; Ma, Jie; Jin, Dan; Yu, Bin

2017-01-01

Aim . The purpose of this study was to investigate the relationship between upper limbs' three functional partitions and the golden curve. Materials and Methods . We measured 30 subjects' right or left upper limb data and investigate the relationship between them and the golden curve by use of SPSS version 20.0 statistical software (SPSS, Inc., Chicago, Illinois), one-sample t -test. Results . There are four points on human's upper limbs which have no difference with the four points on the golden curve. And there is one point of which the difference is obvious. But we still could draw the conclusion that human upper limbs are accordant with the golden curve. Conclusion . Human upper limbs are accordant with the golden curve.

Parallel shifts in ecology and natural selection in an island lizard

PubMed Central

Calsbeek, Ryan; Buermann, Wolfgang; Smith, Thomas B

2009-01-01

Background Natural selection is a potent evolutionary force that shapes phenotypic variation to match ecological conditions. However, we know little about the year-to-year consistency of selection, or how inter-annual variation in ecology shapes adaptive landscapes and ultimately adaptive radiations. Here we combine remote sensing data, field experiments, and a four-year study of natural selection to show that changes in vegetation structure associated with a severe drought altered both habitat use and natural selection in the brown anole, Anolis sagrei. Results In natural populations, lizards increased their use of vegetation in wet years and this was correlated with selection on limb length but not body size. By contrast, a die-back of vegetation caused by drought was followed by reduced arboreality, selection on body size, and relaxed selection on limb length. With the return of the rains and recovery of vegetation, selection reverted back to pre-drought pattern of selection acting on limb length but not body size. To test for the impact of vegetation loss on natural selection during the drought, we experimentally removed vegetation on a separate study island in a naturally wet year. The experiment revealed similar inter-annual changes in selection on body size but not limb length. Conclusion Our results illustrate the dynamic nature of ecology driving natural selection on Anolis morphology and emphasize the importance of inter-annual environmental variation in shaping adaptive variation. In addition, results illustrate the utility of using remote sensing data to examine ecology's role in driving natural selection. PMID:19126226

Microdose acquisition in adolescent leg length discrepancy using a low-dose biplane imaging system.

PubMed

Jensen, Janni; Mussmann, Bo R; Hjarbæk, John; Al-Aubaidi, Zaid; Pedersen, Niels W; Gerke, Oke; Torfing, Trine

2017-09-01

Background Children with leg length discrepancy often undergo repeat imaging. Therefore, every effort to reduce radiation dose is important. Using low dose preview images and noise reduction software rather than diagnostic images for length measurements might contribute to reducing dose. Purpose To compare leg length measurements performed on diagnostic images and low dose preview images both acquired using a low-dose bi-planar imaging system. Material and Methods Preview and diagnostic images from 22 patients were retrospectively collected (14 girls, 8 boys; mean age, 12.8 years; age range, 10-15 years). All images were anonymized and measured independently by two musculoskeletal radiologists. Three sets of measurements were performed on all images; the mechanical axis lines of the femur and the tibia as well as the anatomical line of the entire extremity. Statistical significance was tested with a paired t-test. Results No statistically significant difference was found between measurements performed on the preview and on the diagnostic image. The mean tibial length difference between the observers was -0.06 cm (95% confidence interval [CI], -0.12 to 0.01) and -0.08 cm (95% CI, -0.21 to 0.05), respectively; 0.10 cm (95% CI, 0.02-0.17) and 0.06 cm (95% CI, -0.02 to 0.14) for the femoral measurements and 0.12 cm (95% CI, -0.05 to 0.26) and 0.08 cm (95% CI, -0.02 to 0.19) for total leg length discrepancy. ICCs were >0.99 indicating excellent inter- and intra-rater reliability. Conclusion The data strongly imply that leg length measurements performed on preview images from a low-dose bi-planar imaging system are comparable to measurements performed on diagnostic images.

An assessment of postcranial indices, ratios, and body mass versus eco-geographical variables of prehistoric Jomon, Yayoi agriculturalists, and Kumejima Islanders of Japan.

PubMed

Seguchi, Noriko; Quintyn, Conrad B; Yonemoto, Shiori; Takamuku, Hirofumi

2017-09-10

We explore variations in body and limb proportions of the Jomon hunter-gatherers (14,000-2500 BP), the Yayoi agriculturalists (2500-1700 BP) of Japan, and the Kumejima Islanders of the Ryukyus (1600-1800 AD) with 11 geographically diverse skeletal postcranial samples from Africa, Europe, Asia, Australia, and North America using brachial-crural indices, femur head-breadth-to-femur length ratio, femur head-breadth-to-lower-limb-length ratio, and body mass as indicators of phenotypic climatic adaptation. Specifically, we test the hypothesis that variation in limb proportions seen in Jomon, Yayoi, and Kumejima is a complex interaction of genetic adaptation; development and allometric constraints; selection, gene flow and genetic drift with changing cultural factors (i.e., nutrition) and climate. The skeletal data (1127 individuals) were subjected to principle components analysis, Manly's permutation multiple regression tests, and Relethford-Blangero analysis. The results of Manly's tests indicate that body proportions and body mass are significantly correlated with latitude, and minimum and maximum temperatures while limb proportions were not significantly correlated with these climatic variables. Principal components plots separated "climatic zones:" tropical, temperate, and arctic populations. The indigenous Jomon showed cold-adapted body proportions and warm-adapted limb proportions. Kumejima showed cold-adapted body proportions and limbs. The Yayoi adhered to the Allen-Bergmann expectation of cold-adapted body and limb proportions. Relethford-Blangero analysis showed that Kumejima experienced gene flow indicated by high observed variances while Jomon experienced genetic drift indicated by low observed variances. The complex interaction of evolutionary forces and development/nutritional constraints are implicated in the mismatch of limb and body proportions. © 2017 Wiley Periodicals, Inc.

The relation between height, foot length, pelvic adequacy and mode of delivery.

PubMed

Van Bogaert, L J

1999-02-01

To investigate the value of maternal height and foot length as predictors of pelvic adequacy and to evaluate the influence of body components' proportions on the mode of delivery. Retrospective study of the anthropometry of women having normal vertex deliveries (NVD), caesarean sections (CS) and vaginal birth after caesarean (VBAC). NVD patients were taller, had a longer vertebral column, longer lower limbs and longer feet than CS and than VBAC patients. The anthropometric measurements of VBAC patients yielded values intermediate between CS and NVD patients. The ratios of height to any of the other measured variables (vertebral column, lower limb and foot length) were similar in the three groups indicating that the body proportions were the same. Maternal height and foot length are of limited value as predictors of pelvic (in-)adequacy. The anthropometric features of women delivered by CS only are similar to those of women having a vaginal birth after Caesarean.

Upper limb strength estimation of physically impaired persons using a musculoskeletal model: A sensitivity analysis.

PubMed

Carmichael, Marc G; Liu, Dikai

2015-01-01

Sensitivity of upper limb strength calculated from a musculoskeletal model was analyzed, with focus on how the sensitivity is affected when the model is adapted to represent a person with physical impairment. Sensitivity was calculated with respect to four muscle-tendon parameters: muscle peak isometric force, muscle optimal length, muscle pennation, and tendon slack length. Results obtained from a musculoskeletal model of average strength showed highest sensitivity to tendon slack length, followed by muscle optimal length and peak isometric force, which is consistent with existing studies. Muscle pennation angle was relatively insensitive. The analysis was repeated after adapting the musculoskeletal model to represent persons with varying severities of physical impairment. Results showed that utilizing the weakened model significantly increased the sensitivity of the calculated strength at the hand, with parameters previously insensitive becoming highly sensitive. This increased sensitivity presents a significant challenge in applications utilizing musculoskeletal models to represent impaired individuals.

Hip external rotation strength predicts hop performance after anterior cruciate ligament reconstruction.

PubMed

Kline, Paul W; Burnham, Jeremy; Yonz, Michael; Johnson, Darren; Ireland, Mary Lloyd; Noehren, Brian

2018-04-01

Quadriceps strength and single-leg hop performance are commonly evaluated prior to return to sport after anterior cruciate ligament reconstruction (ACLR). However, few studies have documented potential hip strength deficits after ACLR, or ascertained the relative contribution of quadriceps and hip strength to hop performance. Patients cleared for return to sports drills after ACLR were compared to a control group. Participants' peak isometric knee extension, hip abduction, hip extension, and hip external rotation (HER) strength were measured. Participants also performed single-leg hops, timed hops, triple hops, and crossover hops. Between-limb comparisons for the ACLR to control limb and the non-operative limb were made using independent two-sample and paired sample t tests. Pearson's correlations and stepwise multiple linear regression were used to determine the relationships and predictive ability of limb strength, graft type, sex, and limb dominance to hop performance. Sixty-five subjects, 20 ACLR [11F, age 22.8 (15-45) years, 8.3 ± 2 months post-op, mass 70.47 ± 12.95 kg, height 1.71 ± 0.08 m, Tegner 5.5 (3-9)] and 45 controls [22F, age 25.8 (15-45) years, mass 74.0 ± 15.2 kg, height 1.74 ± 0.1 m, Tegner 6 (3-7)], were tested. Knee extension (4.4 ± 1.5 vs 5.4 ± 1.8 N/kg, p = 0.02), HER (1.4 ± 0.4 vs 1.7 ± 0.5 N/kg, p = 0.04), single-leg hop (146 ± 37 vs 182 ± 38% limb length, p < 0.01), triple hop (417 ± 106 vs 519 ± 102% limb length, p < 0.01), timed hop (3.3 ± 2.0 vs 2.3 ± 0.6 s, p < 0.01), and crossover hop (364 ± 107 vs 446 ± 123% limb length, p = 0.01) were significantly impaired in the operative versus control subject limbs. Similar deficits existed between the operative and non-operative limbs. Knee extension and HER strength were significantly correlated with each of the hop tests, but only HER significantly predicted hop performance. After ACLR, patients have persistent HER strength, knee extension strength, and hop test deficits in the operative limb compared to the control and non-operative limbs, even after starting sport-specific drills. Importantly, HER strength independently predicted hop performance. Based on these findings, to resolve between-limb deficits in strength and hop performance clinicians should include HER strengthening exercises in post-operative rehabilitation. Prognostic Study, Level II.

Pediatric lower limb Ilizarov lengthening with functional evaluation in adulthood: A report on underprivileged patients

PubMed Central

Shahcheraghi, Gholam Hossain; Javid, Mahzad; Hadavi, Fatemeh

2015-01-01

Purpose Ilizarov lengthening, with the principles of Ilizarov, requires a collaboration and supervision of the physiotherapist, nurse, and psychologist, preferably in a group-therapy set-up. We report the mid- and long-term functional outcome of cases that had none of the above listed supporting elements. In addition, we tried to observe the effect of the disease category on the final outcome in the patient. Method In this study, 35 children who had undergone Ilizarov lower limb lengthening were evaluated using the following methods: clinical, radiographic, and by four functional scoring systems, and parent/patient satisfaction questionnaires, after an average of 17.2 years (10–25 years). Results In this study, 19 boys and 16 girls aged 5–16 years received 18 femoral and 20 tibial lengthening. An average of 6.2 cm lengthening in the femur and 8.4 in the tibia was achieved, with a healing index of 26.5 days. The disease category did not significantly affect the healing index, but the complications, 0.5 per femoral and 0.7 per tibial segment, were more common among congenital, and least among post-traumatic discrepancies. A complete improvement in joint stiffness was observed by 6–12 months post-frame removal in 83% of the cases, following home therapy by parents alone. Conclusion The long-term results of Ilizarov lengthening for lower limb discrepancy in children, even without group-therapy or good supportive aids, can improve function and maintain patient satisfaction in two thirds of the cases, over an average period of 17 years. Levels of evidence IV. PMID:26719612

Stimulated Brillouin Scattering Phase Conjugation in Fiber Optic Waveguides

DTIC Science & Technology

2008-07-01

61] The discrepancy is reduced since the effective length of the interaction may be limited by the coherence length of the signal laser as in Eq...these cases, the coherence length of the pulsed laser typically limits the effective length of the Brillouin scattering interaction. Long... coherence length lasers with long fiber SBS media have been used to reduce threshold energy, but as indicated at the end of Chapter 2, this has produced

A Search for Mountain Waves in MLS Stratospheric Limb Radiances from the Winter Northern Hemisphere: Data Analysis and Global Mountain Wave Modeling

DTIC Science & Technology

2004-02-11

the general circulation of the middle atmosphere, Philos. Trans. R. Soc. London, Ser. A, 323, 693–705. Anton , H. (2000), Elementary Linear Algebra ...Because the saturated radiances may depend slightly on tangent height as the limb path length decreases, a linear trend (described by parameters a and b...track days and interpolated onto the same limb-track orbits. The color bar scale for radiance variance is linear . (b) Digital elevations of northern

How muscle fiber lengths and velocities affect muscle force generation as humans walk and run at different speeds

PubMed Central

Arnold, Edith M.; Hamner, Samuel R.; Seth, Ajay; Millard, Matthew; Delp, Scott L.

2013-01-01

SUMMARY The lengths and velocities of muscle fibers have a dramatic effect on muscle force generation. It is unknown, however, whether the lengths and velocities of lower limb muscle fibers substantially affect the ability of muscles to generate force during walking and running. We examined this issue by developing simulations of muscle–tendon dynamics to calculate the lengths and velocities of muscle fibers from electromyographic recordings of 11 lower limb muscles and kinematic measurements of the hip, knee and ankle made as five subjects walked at speeds of 1.0–1.75 m s−1 and ran at speeds of 2.0–5.0 m s−1. We analyzed the simulated fiber lengths, fiber velocities and forces to evaluate the influence of force–length and force–velocity properties on force generation at different walking and running speeds. The simulations revealed that force generation ability (i.e. the force generated per unit of activation) of eight of the 11 muscles was significantly affected by walking or running speed. Soleus force generation ability decreased with increasing walking speed, but the transition from walking to running increased the force generation ability by reducing fiber velocities. Our results demonstrate the influence of soleus muscle architecture on the walk-to-run transition and the effects of muscle–tendon compliance on the plantarflexors' ability to generate ankle moment and power. The study presents data that permit lower limb muscles to be studied in unprecedented detail by relating muscle fiber dynamics and force generation to the mechanical demands of walking and running. PMID:23470656

There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

PubMed

Hagey, Travis J; Harte, Scott; Vickers, Mathew; Harmon, Luke J; Schwarzkopf, Lin

2017-01-01

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

There’s more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads

PubMed Central

Harte, Scott; Vickers, Mathew; Harmon, Luke J.; Schwarzkopf, Lin

2017-01-01

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories. PMID:28953920

Outcome after cementless total hip arthroplasty for arthritic hip in patients with residual poliomyelitis: a case series.

PubMed

Cho, Yoon J; Lee, Choong H; Chun, Young S; Rhyu, Kee H

2016-09-29

In this case series, we investigated the outcome of cementless total hip arthroplasty (THA) for advanced hip osteoarthritis in patients with residual poliomyelitis to evaluate its clinical usefulness for these patients. 11 unilateral cementless primary THA were performed to arthritic hips in patients with residual poliomyelitis. 7 were in paralytic and 4 were in nonparalytic limbs. The mean follow-up duration was 79.9 months. Retrospective clinical evaluations with various scores and radiological evaluations were made. Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Short-form (SF)-36 physical scales were significantly improved after the surgery. However, UCLA activity score and SF-36 mental scale were not. Because of remaining leg length discrepancies, all but 1 noted a residual limp. In nonparalytic hip, functional acetabular cup inclination during weight bearing significantly increased from installed inclination. Other than 1 case of posterior dislocation, no complications were observed. Although the overall result itself is excellent, THA for these patients cannot improve limp, physical activity and mental status. Surgeons should be aware of the change of the inclination of acetabular cup during mobilisation, especially for THA in contralateral hip.

RESISTANCE TO X-IRRADIATION BY EMBRYONIC CELLS OF THE LIMB-BUDS OF TADPOLES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, B.M.; Ewell, L.M.

1959-01-01

Both total-body irradiation and shielding of the trunk were used to study the effects of x irradiation from 1000 to 30000 r upon the limb-buds of Bufo boreas and Hyla regilla tadpoles. The object was to test the view that the younger the cells the more sensitive they are to irradiation. The answer is negative. If there is any special susceptibility of these undifferentiated cells it should appear at levels far below the 30000 r maximum employed. A sharp distinction is made between the very susceptible mitotic cells and the resistant non-dividing embryonic cells that have been accumulated in suchmore » numbers that they may rapidly differentiate into the characteristic limb tissues under the stimulus of the thyroid hormone. Many irradiated ectoderm cells were changed to form bizarre excrescences but were not destroyed. Unicellular cuthneous gland cells continued to arise even after the heaviest irradiation. Irradiated tadpoles with hind limb-buds from 0.6 mm down to 0.2 mm length were unable to develop normal limbs. This capacity was propontional to the number of non-dividing embryonic cells stored at the time of irradiation. Irradiation of 5000, equal degree but the rapidity was greatest in the cases of higher dosage. Not only did these levels of irradiation fail to destroy the non-dividing embryonic cells but they did not effect their pre-deterrmined specificity nor modify their capacity for subsequent differentiation and growth. Exposure to a thyroxin solution caused the hind limb-buds without visible differentiation of cells to grow from a length of 0.8 or 0.9 mm or 1.0 mm at the time of irradiation to a length of as much as 5.0 mm in the course of 7 days. Development of thigh, shank, ankle, and toes was complete. Microscopic studies showed characteristic tissues such as cartilage, connective tissue, and muscle, developed to a comparable degree in control and irradiated specimens. (auth)« less

Calf restoration with asymmetric fat injection in polio sequelae.

PubMed

Yazar, Memet; Kurt Yazar, Sevgi; Kozanoğlu, Erol

2016-09-01

Many things cause leg asymmetry and sequelae seen after poliomyelitis infections are still a cause of leg deformities. In this study, lipofilling and liposuction combinations are performed on patients with poliomyelitis sequelae. Volume deficiency is not the only leg problem with polio sequelae, leg length is also a problem. For this reason, the length deficiency must be addressed in order to achieve the desired symmetry. The aim of this study is correcting limb asymmetry by a method addressing both limb length deficiency by heel raise and volume deficiency by injection of fat based on corrected limb length. From 2011 through 2013, 10 female patients who had unilateral leg atrophy as a result of paediatric polio infections were included in our study. All of the patients were treated with liposuction and lipofilling combinations. During planning, a ridge was placed under the affected leg in order to equalize the lengths of both legs. The fat injection sites on the affected leg were marked to mimic the unaffected leg. All the patients stated that they were satisfied with the results. Transient hypoesthesia was seen in only one patient, but this was spontaneously resolved six months later. The study results indicate that the asymmetric fat injection procedure can be a good technique to use with patients who have polio sequelae, both with short legs and volume deformities. 4. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Cartilaginous Epiphyses in Extant Archosaurs and Their Implications for Reconstructing Limb Function in Dinosaurs

PubMed Central

Holliday, Casey M.; Ridgely, Ryan C.; Sedlmayr, Jayc C.; Witmer, Lawrence M.

2010-01-01

Extinct archosaurs, including many non-avian dinosaurs, exhibit relatively simply shaped condylar regions in their appendicular bones, suggesting potentially large amounts of unpreserved epiphyseal (articular) cartilage. This “lost anatomy” is often underappreciated such that the ends of bones are typically considered to be the joint surfaces, potentially having a major impact on functional interpretation. Extant alligators and birds were used to establish an objective basis for inferences about cartilaginous articular structures in such extinct archosaur clades as non-avian dinosaurs. Limb elements of alligators, ostriches, and other birds were dissected, disarticulated, and defleshed. Lengths and condylar shapes of elements with intact epiphyses were measured. Limbs were subsequently completely skeletonized and the measurements repeated. Removal of cartilaginous condylar regions resulted in statistically significant changes in element length and condylar breadth. Moreover, there was marked loss of those cartilaginous structures responsible for joint architecture and congruence. Compared to alligators, birds showed less dramatic, but still significant changes. Condylar morphologies of dinosaur limb bones suggest that most non-coelurosaurian clades possessed large cartilaginous epiphyses that relied on the maintenance of vascular channels that are otherwise eliminated early in ontogeny in smaller-bodied tetrapods. A sensitivity analysis using cartilage correction factors (CCFs) obtained from extant taxa indicates that whereas the presence of cartilaginous epiphyses only moderately increases estimates of dinosaur height and speed, it has important implications for our ability to infer joint morphology, posture, and the complicated functional movements in the limbs of many extinct archosaurs. Evidence suggests that the sizes of sauropod epiphyseal cartilages surpassed those of alligators, which account for at least 10% of hindlimb length. These data suggest that large cartilaginous epiphyses were widely distributed among non-avian archosaurs and must be considered when making inferences about locomotor functional morphology in fossil taxa. PMID:20927347

A gait retraining system using augmented-reality to modify footprint parameters: Effects on lower-limb sagittal-plane kinematics.

PubMed

Bennour, Sami; Ulrich, Baptiste; Legrand, Thomas; Jolles, Brigitte M; Favre, Julien

2018-01-03

Improving lower-limb flexion/extension angles during walking is important for the treatment of numerous pathologies. Currently, these gait retraining procedures are mostly qualitative, often based on visual assessment and oral instructions. This study aimed to propose an alternative method combining motion capture and display of target footprints on the floor. The second objectives were to determine the error in footprint modifications and the effects of footprint modifications on lower-limb flexion/extension angles. An augmented-reality system made of an optoelectronic motion capture device and video projectors displaying target footprints on the floor was designed. 10 young healthy subjects performed a series of 27 trials, consisting of increased and decreased amplitudes in stride length, step width and foot progression angle. 11 standard features were used to describe and compare lower-limb flexion/extension angles among footprint modifications. Subjects became accustomed to walk on target footprints in less than 10 min, with mean (± SD) precision of 0.020 ± 0.002 m in stride length, 0.022 ± 0.006 m in step width, and 2.7 ± 0.6° in progression angle. Modifying stride length had significant effects on 3/3 hip, 2/4 knee and 4/4 ankle features. Similarly, step width and progression angle modifications affected 2/3 and 1/3 hip, 2/4 and 1/4 knee as well as 3/4 and 2/4 ankle features, respectively. In conclusion, this study introduced an augmented-reality method allowing healthy subjects to modify their footprint parameters rapidly and precisely. Walking with modified footprints changed lower-limb sagittal-plane kinematics. Further research is needed to design rehabilitation protocols for specific pathologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cartilaginous epiphyses in extant archosaurs and their implications for reconstructing limb function in dinosaurs.

PubMed

Holliday, Casey M; Ridgely, Ryan C; Sedlmayr, Jayc C; Witmer, Lawrence M

2010-09-30

Extinct archosaurs, including many non-avian dinosaurs, exhibit relatively simply shaped condylar regions in their appendicular bones, suggesting potentially large amounts of unpreserved epiphyseal (articular) cartilage. This "lost anatomy" is often underappreciated such that the ends of bones are typically considered to be the joint surfaces, potentially having a major impact on functional interpretation. Extant alligators and birds were used to establish an objective basis for inferences about cartilaginous articular structures in such extinct archosaur clades as non-avian dinosaurs. Limb elements of alligators, ostriches, and other birds were dissected, disarticulated, and defleshed. Lengths and condylar shapes of elements with intact epiphyses were measured. Limbs were subsequently completely skeletonized and the measurements repeated. Removal of cartilaginous condylar regions resulted in statistically significant changes in element length and condylar breadth. Moreover, there was marked loss of those cartilaginous structures responsible for joint architecture and congruence. Compared to alligators, birds showed less dramatic, but still significant changes. Condylar morphologies of dinosaur limb bones suggest that most non-coelurosaurian clades possessed large cartilaginous epiphyses that relied on the maintenance of vascular channels that are otherwise eliminated early in ontogeny in smaller-bodied tetrapods. A sensitivity analysis using cartilage correction factors (CCFs) obtained from extant taxa indicates that whereas the presence of cartilaginous epiphyses only moderately increases estimates of dinosaur height and speed, it has important implications for our ability to infer joint morphology, posture, and the complicated functional movements in the limbs of many extinct archosaurs. Evidence suggests that the sizes of sauropod epiphyseal cartilages surpassed those of alligators, which account for at least 10% of hindlimb length. These data suggest that large cartilaginous epiphyses were widely distributed among non-avian archosaurs and must be considered when making inferences about locomotor functional morphology in fossil taxa.

Lower limb fracture presentations at a regional hospital.

PubMed

Holloway, K L; Yousif, D; Bucki-Smith, G; Hosking, S; Betson, A G; Williams, L J; Brennan-Olsen, S L; Kotowicz, M A; Sepetavc, A; Pasco, J A

2017-08-28

We found that lower limb fractures, which were largely the result of minimal trauma, had high levels of hospitalisation, length of stay and surgery. It is therefore important to prevent fractures at all sites to avoid the associated morbidity and mortality. Hip fractures are a major cause of morbidity and mortality, particularly in older women. In comparison, less is known about the epidemiology and burden of other lower limb fractures. The study aimed to investigate the epidemiology and burden of these fractures. Incident fractures of the hip, femur, tibia/fibula, ankle and foot in women (≥ 20 years) managed through the University Hospital Geelong, Australia, were ascertained from 1 Jan. 2014 to 31 Dec. 2014 from radiology reports. Age, cause of fracture, post-fracture hospitalisation, surgery, length of stay and discharge location were ascertained from medical records. We identified 585 fractures of the lower limb (209 hip, 42 femur, 41 tibia/fibula, 162 ankle, 131 foot). Most fractures were sustained by women aged ≥ 50 years. Fractures were largely a result of minimal trauma. Most women with hip or femur fractures were hospitalised; fewer were hospitalised for fractures at other sites. Surgery for fracture followed the same pattern as hospitalisations. Length of stay was the highest for hip and femur fractures and the lowest for foot fractures. Women with hip or femur fractures were discharged to rehabilitation more often than home. Fractures at other sites were most commonly discharged home. Fractures of the lower limb occurred frequently in older women. Hospitalisation and subsequent surgery were common in cases of hip and femur fractures. It is important for prevention strategies to target fractures at a range of skeletal sites to reduce costs, hospitalisations, loss of independence and reduced quality of life.

Abdominal girth and vertebral column length can adjust spinal anesthesia for lower limb surgery, a prospective, observational study.

PubMed

Zhou, Qing-he; Zhu, Bo; Wei, Chang-na; Yan, Min

2016-03-24

Studies have shown that abdominal girth and vertebral column length have high predictive value for spinal spread after administering a dose of plain bupivacaine. we designed a study to identify the specific correlations between abdominal girth, vertebral column length and a 0.5% dosage of plain bupivacaine, which should provide a minimum upper block level (T12) and a suitable upper block level (T10) for lower limb surgeries. A suitable dose of 0.5% plain bupivacaine was administered intrathecally between the L3 and L4 vertebrae for lower limb surgeries. If the upper cephalad spread of the patient by loss of pinprick discrimination was T12 or T10, the patient was enrolled in this study. Five patient variables and intrathecal plain bupivacaine dose were recorded. Linear regression and multiple regression analyses were performed. Totals of 111 patients and 121 patients who lost pinprick discrimination at T12 and T10, respectively, were analyzed in this study. Linear regression analysis showed that only abdominal girth and plain bupivacaine dose were strongly correlated (r =-0.827 for T12, r = -0.806 for T10; both p < 0.0001). Multiple linear regression analysis showed that both abdominal girth and vertebral column length were the key determinants of plain bupivacaine dose (both p < 0.0001). R(2) was 0.874 and 0.860 for the loss of pinprick discrimination at T12 and T10, respectively. Our data indicated that vertebral column length and abdominal girth were strongly correlated with the dosage of intrathecal plain bupivacaine for the loss of pinprick discrimination at T12 and T10. The two regression equations were YT12 = 3.547 + 0.045X1-0.044X2 and YT10 = 3.848 + 0.047X1- 0.046X2 (Y, 0.5% plain bupivacaine volume; X1, vertebral column length;and X 2, abdominal girth), which can accurately predict the minimum and suitable intrathecal bupivacaine dose for lower limb surgery to a great extent, separately.

Airway compliance and dynamics explain the apparent discrepancy in length adaptation between intact airways and smooth muscle strips.

PubMed

Dowie, Jackson; Ansell, Thomas K; Noble, Peter B; Donovan, Graham M

2016-01-01

Length adaptation is a phenomenon observed in airway smooth muscle (ASM) wherein over time there is a shift in the length-tension curve. There is potential for length adaptation to play an important role in airway constriction and airway hyper-responsiveness in asthma. Recent results by Ansell et al., 2015 (JAP 2014 10.1152/japplphysiol.00724.2014) have cast doubt on this role by testing for length adaptation using an intact airway preparation, rather than strips of ASM. Using this technique they found no evidence for length adaptation in intact airways. Here we attempt to resolve this apparent discrepancy by constructing a minimal mathematical model of the intact airway, including ASM which follows the classic length-tension curve and undergoes length adaptation. This allows us to show that (1) no evidence of length adaptation should be expected in large, cartilaginous, intact airways; (2) even in highly compliant peripheral airways, or at more compliant regions of the pressure-volume curve of large airways, the effect of length adaptation would be modest and at best marginally detectable in intact airways; (3) the key parameters which control the appearance of length adaptation in intact airways are airway compliance and the relaxation timescale. The results of this mathematical simulation suggest that length adaptation observed at the level of the isolated ASM may not clearly manifest in the normal intact airway. Copyright © 2015 Elsevier B.V. All rights reserved.

Limb Correction of Individual Infrared Channels Used in RGB Composite Products

NASA Technical Reports Server (NTRS)

Elmer, Nicholas J.; Berndt, Emily; Jedlovec, Gary J.; Lafontaine, Frank J.

2015-01-01

This study demonstrates that limb-cooling can be removed from infrared imagery using latitudinally and seasonally dependent limb correction coefficients, which account for an increasing optical path length as scan angle increases. Furthermore, limb-corrected RGB composites provide multiple advantages over uncorrected RGB composites, including increased confidence in the interpretation of RGB features, improved situation awareness for operational forecasters, seamless transition between overlaid RGB composites, easy comparison of RGB products from different sensors, and the availability of high quality proxy products for the GOES-R era, as demonstrated by the case examples presented in Section 3. This limb correction methodology can also be applied to additional infrared channels used to create other RGB products, including those created from other satellite sensors, such as Suomi NPP Visible Infrared Imaging Radiometer Suite (VIIRS).

Transfer effects of fall training on balance performance and spatiotemporal gait parameters in healthy community-dwelling older adults: a pilot study.

PubMed

Donath, Lars; Faude, Oliver; Bridenbaugh, Stephanie A; Roth, Ralf; Soltermann, Martin; Kressig, Reto W; Zahner, Lukas

2014-07-01

This study examined transfer effects of fall training on fear of falling (Falls Efficacy Scale-International [FES-I]), balance performance, and spatiotemporal gait characteristics in older adults. Eighteen community-dwelling older adults (ages 65-85) were randomly assigned to an intervention or control group. The intervention group completed 12 training sessions (60 min, 6 weeks). During pre- and posttesting, we measured FES-I, balance performance (double limb, closed eyes; single limb, open eyes; double limb, open eyes with motor-interfered task), and gait parameters (e.g., velocity; cadence; stride time, stride width, and stride length; variability of stride time and stride length) under single- and motor-interfered tasks. Dual tasks were applied to appraise improvements of cognitive processing during balance and gait. FES-I (p = .33) and postural sway did not significantly change (0.36 < p < .79). Trends toward significant interaction effects were found for step width during normal walking and stride length variability during the motor dual task (p = .05, ηp 2 = .22). Fall training did not sufficiently improve fear of falling, balance, or gait performance under single- or dual-task conditions in healthy older adults.

Pediatric Traumatic Limb Amputation: The Principles of Management and Optimal Residual Limb Lengths.

PubMed

Khan, Muhammad Adil Abbas; Javed, Ammar Asrar; Rao, Dominic Jordan; Corner, J Antony; Rosenfield, Peter

2016-01-01

Pediatric traumatic limb amputations are rare and their acute and long term management can be challenging in this subgroup of patients. The lengthy and costly hospital stays, and resulting physical and psychological implications leads to significant morbidity. We present a summary of treatment principles and the evidence base supporting the management options for this entity. The initial management focuses on resuscitating and stabilization of the patients, administration of appropriate and adequate analgesics, and broad spectrum antibiotics. The patient should ideally be managed by an orthopedic or a plastic surgeon and when an amputation is warranted, the surgical team should aim to conserve as much of the viable physis as possible aimed at allowing bone development in a growing child. A subsequent wound inspection should be performed to assess for signs of ischemia or non-viability of tissue. Depending on the child's age, approximations of the ideal residual limb length can be calculated using our guidelines, allowing an ideal stump length at skeletal maturity for a well-fitting and appropriate prosthesis. Myodesis and myoplasties can be performed according to the nature of the amputation. Removable rigid dressings are safe and cost effective offering better protection of the stump. Complications such as necrosis and exostosis, on subsequent examination, warrant further revisions. Other complications such as neuromas can be prevented by proximal division of the nerves. Successful rehabilitation can be accomplished with a multidisciplinary approach, involving physiotherapist, play therapist and a child psychiatrist, in addition to the surgeon and primary care providers.

Evaluation of methods for calculating maximum allowable standing height in amputees competing in Paralympic athletics.

PubMed

Connick, M J; Beckman, E; Ibusuki, T; Malone, L; Tweedy, S M

2016-11-01

The International Paralympic Committee has a maximum allowable standing height (MASH) rule that limits stature to a pre-trauma estimation. The MASH rule reduces the probability that bilateral lower limb amputees use disproportionately long prostheses in competition. Although there are several methods for estimating stature, the validity of these methods has not been compared. To identify the most appropriate method for the MASH rule, this study aimed to compare the criterion validity of estimations resulting from the current method, the Contini method, and four Canda methods (Canda-1, Canda-2, Canda-3, and Canda-4). Stature, ulna length, demispan, sitting height, thigh length, upper arm length, and forearm length measurements in 31 males and 30 females were used to calculate the respective estimation for each method. Results showed that Canda-1 (based on four anthropometric variables) produced the smallest error and best fitted the data in males and females. The current method was associated with the largest error of those tests because it increasingly overestimated height in people with smaller stature. The results suggest that the set of Canda equations provide a more valid MASH estimation in people with a range of upper limb and bilateral lower limb amputations compared with the current method. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of ethnicity and sex on the growth of the axial and appendicular skeleton of children living in a developing country.

PubMed

Nyati, Lukhanyo H; Norris, Shane A; Cameron, Noel; Pettifor, John M

2006-05-01

Bones in the axial and appendicular skeletons exhibit heterogeneous growth patterns between different ethnic and sex groups. However, the influence of this differential growth on the expression of bone mineral content is not yet established. The aims of the present study were to investigate: 1) whether there are ethnic and sex differences in axial and appendicular dimensions of South African children; and 2) whether regional segment length is a better predictor of bone mass than stature. Anthropometric measurements of stature, weight, sitting height, and limb lengths were taken on 368 black and white, male and female 9-year-old children. DXA (dual-energy x-ray absorptiometry) scans of the distal ulna, distal radius, and hip and lumbar spine were also obtained. Analyses of covariance were performed to assess differences in limb lengths, adjusted for differences in stature. Multiple regression analyses were used to assess significant predictors of site-specific bone mass. Stature-adjusted means of limb lengths show that black boys have longer legs and humeri but shorter trunks than white boys. In addition, black children have longer forearms than white children, and girls have longer thighs than boys. The regression analysis demonstrated that site-specific bone mass was more strongly associated with regional segment length than stature, but this had little effect on the overall pattern of ethnic and sex differences. In conclusion, there is a differential effect of ethnicity and sex on the growth of the axial and appendicular skeletons, and regional segment length is a better predictor of site-specific bone mass than stature. Copyright 2005 Wiley-Liss, Inc.

The use of tibial tuberosity-trochlear groove indices based on joint size in lower limb evaluation.

PubMed

Ferlic, Peter Wilhelm; Runer, Armin; Dirisamer, Florian; Balcarek, Peter; Giesinger, Johannes; Biedermann, Rainer; Liebensteiner, Michael Christian

2018-05-01

The correlation between tibial tuberosity-trochlear groove distance (TT-TG) and joint size, taking into account several different parameters of knee joint size as well as lower limb dimensions, is evaluated in order to assess whether TT-TG indices should be used in instead of absolute TT-TG values. This study comprised a retrospective analysis of knee CT scans, including 36 cases with patellofemoral instability (PFI) and 30 controls. Besides TT-TG, five measures of knee joint size were evaluated in axial CT slices: medio-lateral femur width, antero-posterior lateral condylar height, medio-lateral width of the tibia, width of the patella and the proximal-distal joint size (TT-TE). Furthermore, the length of the femur, the tibia and the total leg length were measured in the CT scanogram. Correlation analysis of TT-TG and the other parameters was done by calculating the Spearman correlation coefficient. In the PFI group lateral condylar height (r = 0.370), tibia width (r = 0.406) and patella width (r = 0.366) showed significant moderate correlations (p < 0.03) with TT-TG. Furthermore, we found a significant correlation between TT-TG and tibia length (r = 0.371) and total leg length (r = 381). The control group showed no significant correlation between TT-TG and knee joint size or between TT-TG and measures of lower limb length. Tibial tuberosity-trochlear groove distance correlates with several parameters of knee joint size and leg length in patients with patellofemoral instability. Application of indices determining TT-TG as a ratio of joint size could be helpful in establishing the indication for medial transfer of the tibial tuberosity in patients with PFI. Level III.

Habitat relationships and nest site characteristics of cavity-nesting birds in cottonwood floodplains

USGS Publications Warehouse

Sedgwick, James A.; Knopf, Fritz L.

1990-01-01

We examined habitat relationships and nest site characteristics for 6 species of cavity-nesting birds--American kestrel (Falco sparverius), northern flicker (Colaptes auratus), red-headed woodpecker (Melanerpes erythrocephalus), black-capped chickadee (Parus atricapillus), house wren (Troglodytes aedon), and European starling (Sturnus vulgaris)--in a mature plains cottonwood (Populus sargentii) bottomland along the South Platte River in northeastern Colorado in 1985 and 1986. We examined characteristics of cavities, nest trees, and the habitat surrounding nest trees. Density of large trees (>69 cm dbh), total length of dead limbs ≥10 cm diameter (TDLL), and cavity density were the most important habitat variables; dead limb length (DLL), dbh, and species were the most important tree variables; and cavity height, cavity entrance diameter, and substrate condition at the cavity (live vs. dead) were the most important cavity variables in segregating cavity nesters along habitat, tree, and cavity dimensions, respectively. Random sites differed most from cavity-nesting bird sites on the basis of dbh, DLL, limb tree density (trees with ≥1 m dead limbs ≥10 cm diameter), and cavity density. Habitats of red-headed woodpeckers and American kestrels were the most unique, differing most from random sites. Based on current trends in cottonwood demography, densities of cavity-nesting birds will probably decline gradually along the South Platte River, paralleling a decline in DLL, limb tree density, snag density, and the concurrent lack of cottonwood regeneration.

An investigation on effects of amputee's physiological parameters on maximum pressure developed at the prosthetic socket interface using artificial neural network.

PubMed

Nayak, Chitresh; Singh, Amit; Chaudhary, Himanshu; Unune, Deepak Rajendra

2017-10-23

Technological advances in prosthetics have attracted the curiosity of researchers in monitoring design and developments of the sockets to sustain maximum pressure without any soft tissue damage, skin breakdown, and painful sores. Numerous studies have been reported in the area of pressure measurement at the limb/socket interface, though, the relation between amputee's physiological parameters and the pressure developed at the limb/socket interface is still not studied. Therefore, the purpose of this work is to investigate the effects of patient-specific physiological parameters viz. height, weight, and stump length on the pressure development at the transtibial prosthetic limb/socket interface. Initially, the pressure values at the limb/socket interface were clinically measured during stance and walking conditions for different patients using strain gauges placed at critical locations of the stump. The measured maximum pressure data related to patient's physiological parameters was used to develop an artificial neural network (ANN) model. The effects of physiological parameters on the pressure development at the limb/socket interface were examined using the ANN model. The analyzed results indicated that the weight and stump length significantly affects the maximum pressure values. The outcomes of this work could be an important platform for the design and development of patient-specific prosthetic socket which can endure the maximum pressure conditions at stance and ambulation conditions.

Estimation of sex from the lower limb measurements of Sudanese adults.

PubMed

Ahmed, Altayeb Abdalla

2013-06-10

The sex estimation from mutilated and amputated limbs or body parts is one of the most vital steps in person identification in medical-legal autopsies. Sex estimation from lower limb anthropometric measurements has demonstrated a high degree of expected accuracy in a limited range of the global population. The aims of this study were to assess the degree of the sexual dimorphism in lower limb measurements and the accuracy of utilization of these measurements for estimation of sex in a contemporary adult Sudanese population. The tibial length, bimalleolar breadth, foot length, and foot breadth of 240 right-handed Sudanese Arab subjects (120 males and 120 females) aged between 25 and 30 years were measured following international anthropometric standards. Demarking points, sexual dimorphism indices and discriminant functions were developed from 200 subjects (100 males and 100 females) who comprised the study group. All variables were sexually dimorphic. The bimalleolar breadth and foot breadth significantly contributed to sex estimation. Leg dimensions showed a higher accuracy for sex estimation than foot dimensions. Cross-validated sex classification accuracy ranged between 78% and 89.5%. The reliability of these standards was assessed in a test sample of 20 males and 20 females, and the results showed accuracy between 75% and 90%. This study provides new forensic standards for sex estimation from lower limb measurements of Sudanese adults. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Adult outcomes following amputation or lengthening for fibular deficiency.

PubMed

Walker, Janet L; Knapp, Dwana; Minter, Christin; Boakes, Jennette L; Salazar, Juan Carlos; Sanders, James O; Lubicky, John P; Drvaric, David M; Davids, Jon R

2009-04-01

Fibular deficiency results in a small, unstable foot and ankle as well as a limb-length discrepancy. The purpose of this study was to assess outcomes in adults who, as children, had had amputation or limb-lengthening, commonly used treatments for fibular deficiency. Retrospective review of existing data collected since 1950 at six pediatric orthopaedic centers identified 248 patients with fibular deficiency who were twenty-one years of age or older at the time of the review. Excluding patients with other anomalies and other treatments (with the excluded group including six who had had lengthening and then amputation), we identified ninety-eight patients who had had amputation or limb-lengthening for the treatment of isolated unilateral fibular deficiency. Sixty-two patients (with thirty-six amputations and twenty-six lengthening procedures) completed several questionnaires, including one asking general demographic questions, the Beck Depression Inventory-II, the Quality of Life Questionnaire, and the American Academy of Orthopaedic Surgeons Lower Limb Questionnaire including the Short Form-36. A group of twenty-eight control subjects completed the Beck Depression Inventory-II and the Quality of Life Questionnaire. There were forty men and twenty-two women. The average age at the time of the interview was thirty-three years. There were more amputations in those with fewer rays and less fibular preservation. Lengthening resulted in more surgical procedures (6.3 compared with 2.4 in patients treated with amputation) and more days in the hospital (184 compared with sixty-three) (both p<0.0001). However, when we compared treatment outcomes we did not find differences between groups with regard to education, employment, income, public assistance or disability payments, pain or use of pain medicine, sports participation, activity restriction, comfort wearing shorts, dislike of limb appearance, or satisfaction with treatment. No patient who had been treated for fibular deficiency reported signs of depression. The only significant difference between treatment groups shown by the Quality of Life Questionnaire was in the scores on the Job Satisfiers content scale, with the amputees scoring better than the patients treated with lengthening (p=0.015). The American Academy of Orthopaedic Surgeons Lower Limb Module did not demonstrate differences in health-related quality of life or physical function. The patients who were treated with lengthening had started out with more residual foot rays and more fibular preservation than the amputees. They also required more surgical intervention than did those with an amputation. While patients with an amputation spent less of their childhood undergoing treatment, they were found to have a better outcome in terms of only one of seventeen quality-of-life parameters. Both groups of patients who had had treatment of fibular deficiency were functioning at high levels, with an average to above-average quality of life compared with that of the normal adult population.

Contractile function and motor unit firing rates of the human hamstrings.

PubMed

Kirk, Eric A; Rice, Charles L

2017-01-01

Neuromuscular properties of the lower limb in health, aging, and disease are well described for major lower limb muscles comprising the quadriceps, triceps surae, and dorsiflexors, with the notable exception of the posterior thigh (hamstrings). The purpose of this study was to further characterize major muscles of the lower limb by comprehensively exploring contractile properties in relation to spinal motor neuron output expressed as motor unit firing rates (MUFRs) in the hamstrings of 11 (26.5 ± 3.8) young men. Maximal isometric voluntary contraction (MVC), voluntary activation, stimulated contractile properties including a force-frequency relationship, and MUFRs from submaximal to maximal voluntary contractile intensities were assessed in the hamstrings. Strength and MUFRs were assessed at two presumably different muscle lengths by varying the knee joint angles (90° and 160°). Knee flexion MVCs were 60-70% greater in the extended position (160°). The frequency required to elicit 50% of maximum tetanic torque was 16-17 Hz. Mean MUFRs at 25-50% MVC were 9-31% less in the biceps femoris compared with the semimembranosus-semitendinosus group. Knee joint angle (muscle length) influenced MUFRs such that mean MUFRs were greater in the shortened (90°) position at 50% and 100% MVC. Compared with previous reports, mean maximal MUFRs in the hamstrings are greater than those in the quadriceps and triceps surae and somewhat less than those in the tibialis anterior. Mean maximal MUFRs in the hamstrings are influenced by changes in knee joint angle, with lower firing rates in the biceps femoris compared with the semimembranosus-semitendinosus muscle group. We studied motor unit firing rates (MUFRs) at various voluntary contraction intensities in the hamstrings, one of the only major lower limb muscles to have MUFRs affected by muscle length changes. Within the hamstrings muscle-specific differences have greater impact on MUFRs than length changes, with the biceps femoris having reduced neural drive compared with the semimembranosus-semimembranosus. Comparing our results to other lower limb muscles, flexors have inherently higher firing rate compared with extensors. Copyright © 2017 the American Physiological Society.

Contractile function and motor unit firing rates of the human hamstrings

PubMed Central

Kirk, Eric A.

2016-01-01

Neuromuscular properties of the lower limb in health, aging, and disease are well described for major lower limb muscles comprising the quadriceps, triceps surae, and dorsiflexors, with the notable exception of the posterior thigh (hamstrings). The purpose of this study was to further characterize major muscles of the lower limb by comprehensively exploring contractile properties in relation to spinal motor neuron output expressed as motor unit firing rates (MUFRs) in the hamstrings of 11 (26.5 ± 3.8) young men. Maximal isometric voluntary contraction (MVC), voluntary activation, stimulated contractile properties including a force-frequency relationship, and MUFRs from submaximal to maximal voluntary contractile intensities were assessed in the hamstrings. Strength and MUFRs were assessed at two presumably different muscle lengths by varying the knee joint angles (90° and 160°). Knee flexion MVCs were 60–70% greater in the extended position (160°). The frequency required to elicit 50% of maximum tetanic torque was 16–17 Hz. Mean MUFRs at 25–50% MVC were 9–31% less in the biceps femoris compared with the semimembranosus-semitendinosus group. Knee joint angle (muscle length) influenced MUFRs such that mean MUFRs were greater in the shortened (90°) position at 50% and 100% MVC. Compared with previous reports, mean maximal MUFRs in the hamstrings are greater than those in the quadriceps and triceps surae and somewhat less than those in the tibialis anterior. Mean maximal MUFRs in the hamstrings are influenced by changes in knee joint angle, with lower firing rates in the biceps femoris compared with the semimembranosus-semitendinosus muscle group. NEW & NOTEWORTHY We studied motor unit firing rates (MUFRs) at various voluntary contraction intensities in the hamstrings, one of the only major lower limb muscles to have MUFRs affected by muscle length changes. Within the hamstrings muscle-specific differences have greater impact on MUFRs than length changes, with the biceps femoris having reduced neural drive compared with the semimembranosus-semimembranosus. Comparing our results to other lower limb muscles, flexors have inherently higher firing rate compared with extensors. PMID:27784806

Physical and functional measures related to low back pain in individuals with lower-limb amputation: an exploratory pilot study.

PubMed

Friel, Karen; Domholdt, Elizabeth; Smith, Douglas G

2005-01-01

For this study, we compared the physical impairments and functional deficits of individuals with lower-limb amputation (LLA) for those with and without low back pain (LBP). Nineteen participants with LLA were placed into two groups based on visual analog scores of LBP. We assessed functional limitations, iliopsoas length, hamstring length, abdominal strength, back extensor strength, and back extensor endurance. Data analysis included correlations and t-tests. We found significant correlations between pain score and functional limitations, iliopsoas length, and back extensor endurance. We also detected significant differences in functional limitations, iliopsoas length, back extensor strength, and back extensor endurance between those with and without LBP. We saw significant differences in back extensor strength and back extensor endurance between those with transtibial and transfemoral amputations. Differences exist in physical measures of individuals with LLA with and without LBP. Clinicians should consider these impairments in individuals with amputation who experience LBP. Because of the participants' characteristics, these findings may be applicable to veterans with LLA.

Primary central chondrosarcoma of long bone, limb girdle and trunk: Analysis of 174 cases by numerical scoring on histology

PubMed Central

Nakashima, Yasuaki; Mano, Masayuki; Tomita, Yasuhiko; Nagasaki, Ikumitsu; Kubo, Toshikazu; Araki, Nobuhito; Haga, Hironori; Toguchida, Junya; Ueda, Takafumi; Sakuma, Toshiko; Imahori, Masaya; Morii, Eiichi; Yoshikawa, Hideki; Tsukamoto, Yoshitane; Futani, Hiroyuki; Wakasa, Kenichi; Hoshi, Manabu; Hamada, Shinshichi; Takeshita, Hideyuki; Inoue, Takeshi; Aono, Masanari; Kawabata, Kenji; Murata, Hiroaki; Katsura, Kanade; Urata, Yoji; Ueda, Hideki; Yanagisawa, Akio

2015-01-01

The aims of this study were: (i) to elucidate clinicopathological characteristics of pcCHS of long bones (L), limb girdles (LG) and trunk (T) in Japan; (ii) to investigate predictive pathological findings for outcome of pcCHS of L, LG and T, objectively; and (iii) to elucidate a discrepancy of grade between biopsy and resected specimens. Clinicopathological profiles of 174 pcCHS (79 male, 95 female), of L, LG, and T were retrieved. For each case, a numerical score was given to 18 pathological findings. The average age was 50.5 years (15–80 years). Frequently involved sites were femur, humerus, pelvis and rib. The 5‐year and 10‐year disease‐specific survival (DSS) rates [follow‐up: 1–258 months (average 65.5)] were 87.0% and 80.4%, respectively. By Cox hazards analysis on pathological findings, age, sex and location, histologically higher grade and older age were unfavorable predictors, and calcification was a favorable predictor in DSS. The histological grade of resected specimen was higher than that of biopsy in 37.7% (26/69 cases). In conclusion, higher histological grade and older age were predictors for poor, but calcification was for good prognosis. Because there was a discrepancy in grade between biopsy and resected specimens, comprehensive evaluation is necessary before definitive operation for pcCHS. PMID:26126783

Intercomparison of daytime stratospheric NO2 satellite retrievals and model simulations

NASA Astrophysics Data System (ADS)

Belmonte Rivas, M.; Veefkind, P.; Boersma, F.; Levelt, P.; Eskes, H.; Gille, J.

2014-01-01

This paper evaluates the agreement between stratospheric NO2 retrievals from infrared limb sounders (MIPAS and HIRDLS) and solar UV/VIS backscatter sensors (OMI, SCIAMACHY limb and nadir) over the 2005-2007 period and across the seasons. The observational agreement is contrasted with the representation of NO2 profiles in 3-D chemical transport models such as the Whole Atmosphere Community Climate Model (SD-WACCM) and TM4. A conclusion central to this work is that the definition of a reference for stratospheric NO2 columns formed by consistent agreement among SCIAMACHY, MIPAS and HIRDLS limb records (all of which agree to within 0.25 × 1015 molecules cm-2 or better than 10%) allows us to draw attention to relative errors in other datasets, e.g.: (1) the WACCM model overestimates NO2 densities in the extratropical lower stratosphere, particularly over northern latitudes by up to 35% relative to limb observations, and (2) there are remarkable discrepancies between stratospheric NO2 column estimates from limb and nadir techniques, with a characteristic seasonal and latitude dependent pattern. We find that SCIAMACHY nadir and OMI stratospheric columns show overall biases of -0.6 × 1015 molecules cm-2 (-20%) and +0.6 × 10 15 molecules cm-2 (+20%) relative to limb observations. It is highlighted that biases in nadir stratospheric columns are not expected to affect tropospheric retrievals significantly, and that they can be attributed to errors in the total slant column density, either related to algorithmic or instrumental effects. In order to obtain accurate and long time series of stratospheric NO2, a critical evaluation of the currently used Differential Optical Absorption Spectroscopy (DOAS) approaches to nadir retrievals becomes essential, as well as their agreement to limb and ground-based observations, particularly now that limb techniques are giving way to nadir observations as the next generation of climate and air quality monitoring instruments pushes forth.

Growth disturbance in Legg-Calvé-Perthes disease and the consequences of surgical treatment.

PubMed

Leitch, J M; Paterson, D C; Foster, B K

1991-01-01

Seventy-two patients with Legg-Calvé-Perthes disease were studied to assess the interference with proximal femoral growth as a result of the disease itself and of surgical treatment. Twenty-five patients were treated nonoperatively, 20 were treated by femoral varus derotation osteotomy, and 27 by innominate osteotomy. All patients were studied clinically for evidence of abductor weakness and leg-length discrepancy. They were also studied roentgenographically for evidence of femoral head deformity and trochanteric overgrowth. The overall results showed a 6% incidence of leg-length discrepancy greater than 2 cm after both operative and nonoperative treatment. The articulo-trochanteric distance (ATD) was less than +5 mm in 23% of patients, of which 43% had a positive Trendelenburg sign. A significantly lower mean ATD was found in patients treated by femoral varus osteotomy, which should be avoided in patients over eight years of age. The study also demonstrated a strong association between coxa magna and growth disturbance of the proximal femoral physis manifesting itself as either a leg-length discrepancy or as a low ATD. The significant effects of growth disturbance after treatment must be considered, as well as the sphericity of the healed femoral head, in the final assessment in Legg-Calvé-Perthes disease.

Rate of Unverifiable Publications Among Ophthalmology Residency Applicants Invited to Interview.

PubMed

Tamez, Heather M; Tauscher, Robert; Brown, Eric N; Wayman, Laura; Mawn, Louise A

2018-04-19

Unverifiable publications in applications for ophthalmology residencies could be a serious concern if they represent publication dishonesty. To determine the rate of unverifiable publications among applicants offered an interview. Retrospective review of 322 ophthalmology residency applications for entering classes 2012 to 2017 at Vanderbilt University School of Medicine, Nashville, Tennessee. Full-length publications reported in the applications were searched in PubMed, Google, Google Scholar, and directly on the journal's website. Applications were deemed unverifiable if there was no record of the publication by any of these means or if substantial discrepancies existed, such as incorrect authorship, incorrect journal, or a meaningful discrepancy in title or length (full-length article vs abstract). Inability to locate publication with search, incorrect author position, applicant not listed as an author, article being an abstract and not a published paper, substantial title discrepancy suggesting an alternative project, and incorrect journal. Of the 322 applicants offered interviews during the 6-year study period, 22 (6.8%) had 24 unverifiable publications. Two hundred thirty-nine of these applicants (74.2%) reported at least 1 qualifying publication; of this group, 22 (9.2%) had an unverifiable publication. The applications with unverifiable publications were evenly distributed across the years of the study (range, 2-6 per cycle; Pearson χ25 = 3.65; P = .60). Two applicants had 2 unverifiable publications each. Two of the 22 applicants (9.1%) with unverifiable publications were graduates of medical schools outside the United States. Among the unverifiable publications, the most common reason was inability to locate the publication (13 [54%]). Additional issues included abstract rather than full-length publication (5 [20.8%]), incorrect author position (4 [16.7%]), applicant not listed as an author on the publication (1 [4.2%]), and substantial title discrepancy (1 [4.2%]). One listed publication had an incorrect author position and incorrect journal (1 [4.2%]). Unverifiable publications among ophthalmology residency applicants is a persistent problem. Possible strategies to modify the review process include asking applicants to provide copies of their full-length works or the relevant PMCID (PubMed Central reference number) or DOI (digital object identifier) for their publications.

Quantification of facial and smile esthetics.

PubMed

Koidou, Vasiliki P; Chatzopoulos, Georgios S; Rosenstiel, Stephen F

2018-02-01

Whether deviations in alignment discrepancy, width-to-length ratio, application of the golden proportion, or number of teeth revealed in smile affect attractiveness is yet unknown. The purpose of this analytical study was to quantify dental and facial esthetics to determine whether individuals identified as having superior smiles display differences in alignment discrepancies (angulation between interpupillary and commissure line); width-to-length ratios of maxillary anterior teeth; application of the golden proportion (approximately 1.618:1); and number of teeth revealed in an animated smile when compared with an average population. An Internet search for "best smile" and "celebrity" identified 108 celebrities. Photographs showing smiles within 10 degrees of a frontal view were collected, while photographs of dental students were used for the control group. Alignment discrepancies, widths and lengths of the anterior teeth, and number of teeth revealed in an animated smile were measured with photo-editing software, and ratios were calculated. The groups were compared with repeated-measures ANOVA, the Mann-Whitney U test, and the Wilcoxon signed-rank test (α=.05). Usable photographs were obtained for 90 celebrities (58 women, 32 men) and compared with photographs of 97 dental students (54 women, 43 men). Statistically significant differences were found for alignment discrepancies (celebrities 0.97, students 1.25, P=.034) and for the number of teeth displayed (P=.049); 22.2% of the celebrities revealed 12 teeth, versus 6.2% of the students. In both groups, significant differences from the golden ratio (1.618:1) for the width of the central incisor/lateral incisor right and left and for the width of the lateral incisor/canine right and left were observed through 95% confidence intervals. Sex and left-right were nonsignificant factors. Celebrities identified as having a best smile had smaller mean alignment discrepancies and revealed a greater number of teeth in an animated smile than dental students. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Effects of experimental leg length discrepancies on body posture and dental occlusion.

PubMed

Maeda, Nozomi; Sakaguchi, Kiwamu; Mehta, Noshir R; Abdallah, Emad F; Forgione, Albert G; Yokoyama, Atsuro

2011-07-01

The purpose of this study was to quantitatively evaluate the effects of experimental leg length discrepancies on body posture and dental occlusion. Thirty asymptomatic subjects (15 males and 15 females, ages 19-33, mean age 25.6 years) were included in this study and randomly assigned to one of two groups based on a table of random numbers. The only difference between group A and group B was the sequence of testing. Experimental leg length discrepancies were provided by using ten types of insoles with heights ranging from one to ten mm at one mm intervals, placed under both feet. The MatScan (Nitta Corp., Osaka, Japan) system was used to measure changes in body posture (center of foot pressure: COP) while subjects maintained the following three postural positions: 1. natural standing posture (control); 2. control with a heel lift under the right foot; or 3. control with a heel lift under the left foot. The T-Scan II system (Nitta Corp., Osaka, Japan) was used to analyze the results of changes in dental occlusion (center of occlusal force: COF) in the above-mentioned three postural positions. When subjects used a heel lift of six mm or more under the right foot, lateral weight distribution (LWD) shifted to the right side compared to the control (p<0.05). When a heel lift of four mm or more was used under the left foot, LWD shifted to the left side compared to the control (p<0.05). When subjects used a heel lift of eight mm or more under the right foot, occlusal force shifted to the right side compared to the control (p<0.05). When subjects used a heel lift of seven mm or more under the left foot, occlusal force shifted to the left side compared to the control (p<0.05). Based on these findings, it was concluded that leg length discrepancy affected body posture and dental occlusion.

An assistive controller for a lower-limb exoskeleton for rehabilitation after stroke, and preliminary assessment thereof.

PubMed

Murray, Spencer A; Ha, Kevin H; Goldfarb, Michael

2014-01-01

This paper describes a novel controller, intended for use in a lower-limb exoskeleton, to aid gait rehabilitation in patients with hemiparesis after stroke. The controller makes use of gravity compensation, feedforward movement assistance, and reinforcement of isometric joint torques to achieve assistance without dictating the spatiotemporal nature of joint movement. The patient is allowed to self-select walking speed and is able to make trajectory adaptations to maintain balance without interference from the controller. The governing equations and the finite state machine which comprise the system are described herein. The control architecture was implemented in a lower-limb exoskeleton and a preliminary experimental assessment was conducted in which a patient with hemiparesis resulting from stroke walked with assistance from the exoskeleton. The patient exhibited improvements in fast gait speed, step length asymmetry, and stride length in each session, as measured before and after exoskeleton training, presumably as a result of using the exoskeleton.

Comparison of injury rates between cadets with limb length inequalities and matched control subjects over 1 year of military training and athletic participation.

PubMed

Goss, Donald Lee; Moore, Josef H; Slivka, Erin M; Hatler, Brian S

2006-06-01

To compare lower-limb overuse injury and low back pain incidence among cadets with and without limb length inequality (LLI) over 1 year of military training and athletic participation. A total of 1,100 cadets were screened for LLIs; 126 of 1,100 were identified to have a LLI of > 0.5 cm and were assigned a matched control cadet. Injury rates, numbers of visits to sick call, and numbers of days spent on medical excusal during a 1-year period were then compared for the 252 cadets. There was no difference in prevalence of injury between the groups and no significant differences (p > 0.05) between the groups in injury rates, visits to sick call, or number of days spent on medical excusal. These findings do not support any increased incidence of injuries in a young, healthy, athletic, military population with mild LLIs, compared with matched control subjects without LLIs, over 1 year.

Long-term outcome of dogs treated with ulnar rollover transposition for limb-sparing of distal radial osteosarcoma: 27 limbs in 26 dogs.

PubMed

Séguin, Bernard; O'Donnell, Matthew D; Walsh, Peter J; Selmic, Laura E

2017-10-01

To determine outcomes in dogs with distal radial osteosarcoma treated with ulnar rollover transposition (URT) limb-sparing surgery including: viability of the ulnar graft, complications, subjective limb function, disease-free interval (DFI), and survival time (ST). Retrospective case series. Twenty-six client-owned dogs with distal radial osteosarcoma and no involvement of the ulna. Data of dogs treated with URT were collected at the time of surgery and retrospectively from medical records and by contacting owners and referring veterinarians. URT technique was performed on 27 limbs in 26 dogs. The ulnar graft was determined to be viable in 17 limbs, nonviable in 3, and unknown in 7. Complications occurred in 20 limbs. Infection was diagnosed in 12 limbs. Biomechanical complications occurred in 15 and local recurrence in 2 limbs. Limb function graded by veterinarians or owners was poor in 2 limbs, fair in 4, good in 14, excellent in 3, and unknown in 4. Median DFI was 245 days and median ST was 277 days. The URT technique maintained the viability of the ulnar graft. The complication rate was high but limb function appeared acceptable. Although sufficient length of the distal aspect of the ulna must be preserved to perform this technique, local recurrence was not increased compared to other limb-sparing techniques when cases were appropriately selected. © 2017 The American College of Veterinary Surgeons.

Discrepancies Between Plastic Surgery Meeting Abstracts and Subsequent Full-Length Manuscript Publications.

PubMed

Denadai, Rafael; Araujo, Gustavo Henrique; Pinho, Andre Silveira; Denadai, Rodrigo; Samartine, Hugo; Raposo-Amaral, Cassio Eduardo

2016-10-01

The purpose of this bibliometric study was to assess the discrepancies between plastic surgery meeting abstracts and subsequent full-length manuscript publications. Abstracts presented at the Brazilian Congress of Plastic Surgery from 2010 to 2011 were compared with matching manuscript publications. Discrepancies between the abstract and the subsequent manuscript were categorized as major (changes in the purpose, methods, study design, sample size, statistical analysis, results, and conclusions) and minor (changes in the title and authorship) variations. The overall discrepancy rate was 96 %, with at least one major (76 %) and/or minor (96 %) variation. There were inconsistencies between the study title (56 %), authorship (92 %), purpose (6 %), methods (20 %), study design (36 %), sample size (51.2 %), statistical analysis (14 %), results (20 %), and conclusions (8 %) of manuscripts compared with their corresponding meeting abstracts. As changes occur before manuscript publication of plastic surgery meeting abstracts, caution should be exercised in referencing abstracts or altering surgical practices based on abstracts' content. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Distributed force feedback in the spinal cord and the regulation of limb mechanics.

PubMed

Nichols, T Richard

2018-03-01

This review is an update on the role of force feedback from Golgi tendon organs in the regulation of limb mechanics during voluntary movement. Current ideas about the role of force feedback are based on modular circuits linking idealized systems of agonists, synergists, and antagonistic muscles. In contrast, force feedback is widely distributed across the muscles of a limb and cannot be understood based on these circuit motifs. Similarly, muscle architecture cannot be understood in terms of idealized systems, since muscles cross multiple joints and axes of rotation and further influence remote joints through inertial coupling. It is hypothesized that distributed force feedback better represents the complex mechanical interactions of muscles, including the stresses in the musculoskeletal network born by muscle articulations, myofascial force transmission, and inertial coupling. Together with the strains of muscle fascicles measured by length feedback from muscle spindle receptors, this integrated proprioceptive feedback represents the mechanical state of the musculoskeletal system. Within the spinal cord, force feedback has excitatory and inhibitory components that coexist in various combinations based on motor task and integrated with length feedback at the premotoneuronal and motoneuronal levels. It is concluded that, in agreement with other investigators, autogenic, excitatory force feedback contributes to propulsion and weight support. It is further concluded that coexistent inhibitory force feedback, together with length feedback, functions to manage interjoint coordination and the mechanical properties of the limb in the face of destabilizing inertial forces and positive force feedback, as required by the accelerations and changing directions of both predator and prey.

A novel method to guide classification of para swimmers with limb deficiency.

PubMed

Hogarth, Luke; Payton, Carl; Van de Vliet, Peter; Connick, Mark; Burkett, Brendan

2018-05-30

The International Paralympic Committee has directed International Federations that govern Para sports to develop evidence-based classification systems. This study defined the impact of limb deficiency impairment on 100 m freestyle performance to guide an evidence-based classification system in Para Swimming, which will be implemented following the 2020 Tokyo Paralympic games. Impairment data and competitive race performances of 90 international swimmers with limb deficiency were collected. Ensemble partial least squares regression established the relationship between relative limb length measures and competitive 100 m freestyle performance. The model explained 80% of the variance in 100 m freestyle performance, and found hand length and forearm length to be the most important predictors of performance. Based on the results of this model, Para swimmers were clustered into four-, five-, six- and seven-class structures using nonparametric kernel density estimations. The validity of these classification structures, and effectiveness against the current classification system, were examined by establishing within-class variations in 100 m freestyle performance and differences between adjacent classes. The derived classification structures were found to be more effective than current classification based on these criteria. This study provides a novel method that can be used to improve the objectivity and transparency of decision-making in Para sport classification. Expert consensus from experienced coaches, Para swimmers, classifiers and sport science and medicine personnel will benefit the translation of these findings into a revised classification system that is accepted by the Para swimming community. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pediatric Traumatic Limb Amputation: The Principles of Management and Optimal Residual Limb Lengths

PubMed Central

Khan, Muhammad Adil Abbas; Javed, Ammar Asrar; Rao, Dominic Jordan; Corner, J Antony; Rosenfield, Peter

2016-01-01

Pediatric traumatic limb amputations are rare and their acute and long term management can be challenging in this subgroup of patients. The lengthy and costly hospital stays, and resulting physical and psychological implications leads to significant morbidity. We present a summary of treatment principles and the evidence base supporting the management options for this entity. The initial management focuses on resuscitating and stabilization of the patients, administration of appropriate and adequate analgesics, and broad spectrum antibiotics. The patient should ideally be managed by an orthopedic or a plastic surgeon and when an amputation is warranted, the surgical team should aim to conserve as much of the viable physis as possible aimed at allowing bone development in a growing child. A subsequent wound inspection should be performed to assess for signs of ischemia or non-viability of tissue. Depending on the child’s age, approximations of the ideal residual limb length can be calculated using our guidelines, allowing an ideal stump length at skeletal maturity for a well-fitting and appropriate prosthesis. Myodesis and myoplasties can be performed according to the nature of the amputation. Removable rigid dressings are safe and cost effective offering better protection of the stump. Complications such as necrosis and exostosis, on subsequent examination, warrant further revisions. Other complications such as neuromas can be prevented by proximal division of the nerves. Successful rehabilitation can be accomplished with a multidisciplinary approach, involving physiotherapist, play therapist and a child psychiatrist, in addition to the surgeon and primary care providers. PMID:27308235

[Kinetics of heifers and cows walking on an instrumented treadmill].

PubMed

Nuss, K; Waldern, N M; Weishaupt, M A; Wiestner, T

2015-01-01

Kinetic data of stride characteristics and ground reaction forces of cattle become increasingly important as automated lameness detection may be installed in dairy cow housing systems in the future. Therefore, sound heifers and cows were measured on an instrumented treadmill to collect such basic data. Nine heifers and 10 cows were trained to walk on an instrumented treadmill. Vertical ground reaction forces as well as step and stride timing and length variables were measured for all limbs simultaneously. On average, 16 stride cycles in cows and 24 strides in heifers were analysed in each case. The cows walked on the treadmill at an average speed of 1.2 ± 0.05 m/s (mean ± standard deviation), with a stride rate of 43.0 ± 1.9/min and a stride length of 1.68 ± 0.1 m. The heifers had average values of 1.3 ± 0.04 m/s, 53.7 ± 2.2/min and 1.49 ± 0.05 m, respectively. The stance duration relative to stride duration (the duty factor) was for the cows significantly longer in the forelimbs (67%) than in the hind limbs (64%). Force-time-curves of all limbs showed two peaks, one after landing (FP1) and another during push off (FP2). Vertical ground reaction force was highest for FP1 in the hind limbs, but for FP2 in the forelimbs. At all limbs, force minimum between the peaks occurred shortly before midstance. The vertical impulse carried by both forelimbs amounted to 53.7% of the total stride impulse in cows and to 55.0% in heifers. The location of the centre of body mass varied during the stride cycle but was always located more towards the front limbs. Cows and heifers showed a symmetrical walk with minimal intra-individual variations. Relative stride impulse of the front limbs was higher than that of the hind limbs. Peak vertical force in the hind limbs was highest at landing and in the forelimbs at push off. The present study offers kinetic data of sound cows and heifers which might be helpful as guidelines for automated systems for lameness detection in cattle.

Double plication for spring-mediated intestinal lengthening of a defunctionalized Roux limb.

PubMed

Dubrovsky, Genia; Huynh, Nhan; Thomas, Anne-Laure; Shekherdimian, Shant; Dunn, James C Y

2017-12-26

Spring-mediated distraction enterogenesis has been shown to increase the length of an intestinal segment. The goal of this study is to use suture plication to confine a spring within an intestinal segment while maintaining luminal patency to the rest of the intestine. Juvenile mini-Yucatan pigs underwent placement of nitinol springs within a defunctionalized Roux limb of jejunum. A 20 French catheter was passed temporarily, and sutures were used to plicate the intestinal wall around the catheter at both ends of the encapsulated spring. Uncompressed springs placed in plicated segments and springs placed in nonplicated segments served as controls. The intestine was examined approximately 3 weeks after spring placement. In the absence of plication, springs passed through the intestine within a week. Double plication allowed the spring to stay within the Roux limb for 3 weeks. Compared to uncompressed springs that showed no change in the length of plicated segments, compressed springs caused a significant 1.7-fold increase in the length of plicated segments. Intestinal plication is an effective method to confine endoluminal springs. The confined springs could lengthen intestine that maintains luminal patency. This approach may be useful to lengthen intestine in patients with short bowel syndrome. Level I Experimental Study. Copyright © 2018. Published by Elsevier Inc.

Analysis of the intermediate size proteoglycans from the developing chick limb buds.

PubMed

Vasan, N

1982-08-01

Limb-bud proteoglycans are heterogeneous molecules which vary in their chemical and physical properties with development. This report describes proteoglycan intermediates (PG-I) that predominate in stage-34 limbs, and compares them with proteoglycan aggregates (PG-A) in stage-38 limbs. We analysed proteoglycans and their components extracted with guanidinium chloride by subjecting them to density gradient centrifugation, molecular sieve chromatography, electrophoretic separation, and selective enzymatic degradation. PG-I and PG-A have similar chondroitin sulphate composition, amino sugars, chondroitin sulphate side-chain length, glycoprotein link factors, and hyaluronic acid binding capacity, and both cross react with antisera prepared against cartilage-specific chick sternal proteoglycans. However, PG-I has lower molecular weight, lower buoyant density, and fewer chondroitin sulphate side chains on the protein core. The PG-I in the developing limb can be considered a mixture of smaller aggregates and cartilage-specific large monomers in which the former predominate.

The Effect of Hemispatial Neglect on the Perception of Centre

ERIC Educational Resources Information Center

Olk, Bettina; Wee, Joy; Kingstone, Alan

2004-01-01

Highly variable bisection performance in neglect patients has been attributed to an increased "zone of indifference" (Marshall & Halligan, 1989). The indifference zone indicates the discrepancy between two line lengths which are judged as equal in length. Following this argumentation, the central area of a line should be expanded in neglect…

Shape adjustment optimization and experiment of cable-membrane reflectors

NASA Astrophysics Data System (ADS)

Du, Jingli; Gu, Yongzhen; Bao, Hong; Wang, Congsi; Chen, Xiaofeng

2018-05-01

Cable-membrane structures are widely employed for large space reflectors due to their lightweight, compact and easy package. In these structures, membranes are attached to cable net, serving as reflectors themselves or as supporting structures for other reflective surface. The cable length and membrane shape have to be carefully designed and fabricated to guarantee the desired reflector surface shape. However, due to inevitable error in cable length and membrane shape during the manufacture and assembly of cable-membrane reflectors, some cables have to be designed to be capable of length adjustment. By carefully adjusting the length of these cables, the degeneration in reflector shape precision due to this inevitable error can be effectively reduced. In the paper a shape adjustment algorithm for cable-membrane reflectors is proposed. Meanwhile, model updating is employed during shape adjustment to decrease the discrepancy of the numerical model with respect to the actual reflector. This discrepancy has to be considered because during attaching membranes to cable net, the accuracy of the membrane shape is hard to guarantee. Numerical examples and experimental results demonstrate the proposed method.

Intercomparison of daytime stratospheric NO2 satellite retrievals and model simulations

NASA Astrophysics Data System (ADS)

Belmonte Rivas, M.; Veefkind, P.; Boersma, F.; Levelt, P.; Eskes, H.; Gille, J.

2014-07-01

This paper evaluates the agreement between stratospheric NO2 retrievals from infrared limb sounders (Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and High Resolution Dynamics Limb Sounder (HIRDLS)) and solar UV/VIS backscatter sensors (Ozone Monitoring Instrument (OMI), Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) limb and nadir) over the 2005-2007 period and across the seasons. The observational agreement is contrasted with the representation of NO2 profiles in 3-D chemical transport models such as the Whole Atmosphere Community Climate Model (WACCM) and TM4. A conclusion central to this work is that the definition of a reference for stratospheric NO2 columns formed by consistent agreement among SCIAMACHY, MIPAS and HIRDLS limb records (all of which agree to within 0.25 × 1015 molecules cm-2 or better than 10%) allows us to draw attention to relative errors in other data sets, e.g., (1) WACCM overestimates NO2 densities in the extratropical lower stratosphere, particularly in the springtime and over northern latitudes by up to 35% relative to limb observations, and (2) there are remarkable discrepancies between stratospheric NO2 column estimates from limb and nadir techniques, with a characteristic seasonally and latitudinally dependent pattern. We find that SCIAMACHY nadir and OMI stratospheric columns show overall biases of -0.5 × 1015 molecules cm-2 (-20%) and +0.6 × 1015 molecules cm-2 (+20%) relative to limb observations, respectively. It is argued that additive biases in nadir stratospheric columns are not expected to affect tropospheric retrievals significantly, and that they can be attributed to errors in the total slant column density, related either to algorithmic or instrumental effects. In order to obtain accurate and long-term time series of stratospheric NO2, an effort towards the harmonization of currently used differential optical absorption spectroscopy (DOAS) approaches to nadir retrievals becomes essential, as well as their agreement to limb and ground-based observations, particularly now that limb techniques are giving way to nadir observations as the next generation of climate and air quality monitoring instruments pushes forth.

Various methods for assessing static lower extremity alignment: implications for prospective risk-factor screenings.

PubMed

Nguyen, Anh-Dung; Boling, Michelle C; Slye, Carrie A; Hartley, Emily M; Parisi, Gina L

2013-01-01

Accurate, efficient, and reliable measurement methods are essential to prospectively identify risk factors for knee injuries in large cohorts. To determine tester reliability using digital photographs for the measurement of static lower extremity alignment (LEA) and whether values quantified with an electromagnetic motion-tracking system are in agreement with those quantified with clinical methods and digital photographs. Descriptive laboratory study. Laboratory. Thirty-three individuals participated and included 17 (10 women, 7 men; age = 21.7 ± 2.7 years, height = 163.4 ± 6.4 cm, mass = 59.7 ± 7.8 kg, body mass index = 23.7 ± 2.6 kg/m2) in study 1, in which we examined the reliability between clinical measures and digital photographs in 1 trained and 1 novice investigator, and 16 (11 women, 5 men; age = 22.3 ± 1.6 years, height = 170.3 ± 6.9 cm, mass = 72.9 ± 16.4 kg, body mass index = 25.2 ± 5.4 kg/m2) in study 2, in which we examined the agreement among clinical measures, digital photographs, and an electromagnetic tracking system. We evaluated measures of pelvic angle, quadriceps angle, tibiofemoral angle, genu recurvatum, femur length, and tibia length. Clinical measures were assessed using clinically accepted methods. Frontal- and sagittal-plane digital images were captured and imported into a computer software program. Anatomic landmarks were digitized using an electromagnetic tracking system to calculate static LEA. Intraclass correlation coefficients and standard errors of measurement were calculated to examine tester reliability. We calculated 95% limits of agreement and used Bland-Altman plots to examine agreement among clinical measures, digital photographs, and an electromagnetic tracking system. Using digital photographs, fair to excellent intratester (intraclass correlation coefficient range = 0.70-0.99) and intertester (intraclass correlation coefficient range = 0.75-0.97) reliability were observed for static knee alignment and limb-length measures. An acceptable level of agreement was observed between clinical measures and digital pictures for limb-length measures. When comparing clinical measures and digital photographs with the electromagnetic tracking system, an acceptable level of agreement was observed in measures of static knee angles and limb-length measures. The use of digital photographs and an electromagnetic tracking system appears to be an efficient and reliable method to assess static knee alignment and limb-length measurements.

Coordinated Body Bending Improves Performance of a Salamander-like Robot

NASA Astrophysics Data System (ADS)

Ozkan Aydin, Yasemin; Chong, Baxi; Gong, Chaohui; Rieser, Jennifer M.; Choset, Howie; Goldman, Daniel I.

Analyzing body morphology and limb-body coordination in animals that can both swim and walk is important to understand the evolutionary transition from an aquatic to a terrestrial environment. Based on previous salamander experiments (a modern analog to early tetrapods and performed by Hutchinson's group at RVC in the UK) we built a robophysical model of a salamander and tested its performance on yielding granular media (GM) of poppy seeds. Our servo-driven robot (405 g, 38 cm long) has four limbs, a flexible body, and an active tail. Each limb has two servo motors to control up/down and fore/aft positions of limb. A joint in the middle of the body controls horizontal bending. We assessed performance of the robot by changing the body bending limit from 0°to 90°and measured body displacement and power consumption over a few limb cycles at 0°and 10°sandy slope. We fixed the angle of the legs according to body to test the effect of body bending directly. On GM, step length increased from 0 to 9.5 cm at 0° and 0 to 7 cm at 10°slope while the average power consumption increased 50 % . A geometric mechanics model revealed that on level GM body bending was most beneficial when phase offset 180°from leg movements; increasing the maximum body angular bend from 45°to 90° led to step length increases of up to 90 % .

Lower Extremity Limb Salvage with Cross Leg Pedicle Flap, Cross Leg Free Flap, and Cross Leg Vascular Cable Bridge Flap.

PubMed

Manrique, Oscar J; Bishop, Sarah N; Ciudad, Pedro; Adabi, Kian; Martinez-Jorge, Jorys; Moran, Steven L; Huang, Tony; Vijayasekaran, Aparna; Chen, Shih-Heng; Chen, Hung-Chi

2018-05-16

 Lower extremity salvage following significant soft tissue loss can be complicated by lack of recipient vessel for free tissue transfer. We describe our experience in lower limb salvage for patients with no recipient vessels with the use of pedicle, free and cable bridge flaps.  A retrospective review from 1985 to 2017 of patients undergoing lower limb salvage using a contralateral pedicle cross leg (PCL) flaps, free cross leg (FCL) flaps, or free cable bridge (FCB) flaps was conducted. Demographics, etiology of the reconstruction, type of flap used, donor-site vessels, defect size, operating time, time of pedicle division, length of hospital stay, time to ambulation, and complications were analyzed.  A total of 53 patients (48 males and 5 females) with an average age of 35 years (range, 29-38 years) were identified. The etiology for the reconstruction was trauma in 52 patients and oncological resection in 1 patient. There were 18 PCL, 25 FCL, and 10 FCB completed. The recipient vessels for all flaps were the posterior tibial artery and vein. The average operating room times for PCL, FCL, and FCB flaps were 4, 9, and 10 hours, respectively. The average length of hospital stay was 5 weeks and average time to ambulation was 4 weeks. The average follow-up time was 7.5 years (range, 3-12 years). Complications encountered were hematoma (six), prolonged pain (six), total flap loss (two), reoperation (five), and infection (four). Limb salvage rates were 96.2%.  When ipsilateral limb vessels are not available, and other reconstructive options have been exhausted, cross leg flaps can be a viable option for limb salvage in the setting of extensive defects. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Accuracy of self-reported length of coma and posttraumatic amnesia in persons with medically verified traumatic brain injury.

PubMed

Sherer, Mark; Sander, Angelle M; Maestas, Kacey Little; Pastorek, Nicholas J; Nick, Todd G; Li, Jingyun

2015-04-01

To determine the accuracy of self-reported length of coma and posttraumatic amnesia (PTA) in persons with medically verified traumatic brain injury (TBI) and to investigate factors that affect self-report of length of coma and PTA duration. Prospective cohort study. Specialized rehabilitation center with inpatient and outpatient programs. Persons (N=242) with medically verified TBI who were identified from a registry of persons who had previously participated in TBI-related research. Not applicable. Self-reported length of coma and self-reported PTA duration. Review of medical records revealed that the mean medically documented length of coma and PTA duration was 6.9±12 and 19.2±22 days, respectively, and the mean self-reported length of coma and PTA duration was 16.7±22 and 106±194 days, respectively. The average discrepancy between self-report and medical record for length of coma and PTA duration was 8.2±21 and 64±176 days, respectively. Multivariable regression models revealed that time since injury, performance on cognitive tests, and medical record values were associated with self-reported values for both length of coma and PTA duration. In this investigation, persons with medically verified TBI showed poor accuracy in their self-report of length of coma and PTA duration. Discrepancies were large enough to affect injury severity classification. Caution should be exercised when considering self-report of length of coma and PTA duration. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Corticomotor excitability of arm muscles modulates according to static position and orientation of the upper limb.

PubMed

Mogk, Jeremy P M; Rogers, Lynn M; Murray, Wendy M; Perreault, Eric J; Stinear, James W

2014-10-01

We investigated how multi-joint changes in static upper limb posture impact the corticomotor excitability of the posterior deltoid (PD) and biceps brachii (BIC), and evaluated whether postural variations in excitability related directly to changes in target muscle length. The amplitude of individual motor evoked potentials (MEPs) was evaluated in each of thirteen different static postures. Four functional postures were investigated that varied in shoulder and elbow angle, while the forearm was positioned in each of three orientations. Posture-related changes in muscle lengths were assessed using a biomechanical arm model. Additionally, M-waves were evoked in the BIC in each of three forearm orientations to assess the impact of posture on recorded signal characteristics. BIC-MEP amplitudes were altered by shoulder and elbow posture, and demonstrated robust changes according to forearm orientation. Observed changes in BIC-MEP amplitudes exceeded those of the M-waves. PD-MEP amplitudes changed predominantly with shoulder posture, but were not completely independent of influence from forearm orientation. Results provide evidence that overall corticomotor excitability can be modulated according to multi-joint upper limb posture. The ability to alter motor pathway excitability using static limb posture suggests the importance of posture selection during rehabilitation aimed at retraining individual muscle recruitment and/or overall coordination patterns. Published by Elsevier Ireland Ltd.

Symmetrical kinematics does not imply symmetrical kinetics in people with transtibial amputation using cycling model.

PubMed

Childers, W Lee; Kogler, Géza F

2014-01-01

People with amputation move asymmetrically with regard to kinematics (joint angles) and kinetics (joint forces and moments). Clinicians have traditionally sought to minimize kinematic asymmetries, assuming kinetic asymmetries would also be minimized. A cycling model evaluated locomotor asymmetries. Eight individuals with unilateral transtibial amputation pedaled with 172 mm-length crank arms on both sides (control condition) and with the crank arm length shortened to 162 mm on the amputated side (CRANK condition). Pedaling kinetics and limb kinematics were recorded. Joint kinetics, joint angles (mean and range of motion [ROM]), and pedaling asymmetries were calculated from force pedals and with a motion capture system. A one-way analysis of variance with tukey post hoc compared kinetics and kinematics across limbs. Statistical significance was set to p

Limb lengthening over plate

PubMed Central

Kulkarni, Ruta; Singh, Nishant; Kulkarni, Govind S; Kulkarni, Milind; Kulkarni, Sunil; Kulkarni, Vidisha

2012-01-01

Background: The limb lengthening over plate eliminates the associated risk of infection with limb lengthening over intramedullary nail. We present our experience of limb lengthening in 15 patients with a plate fixed on the proximal segment, followed by corticotomy and application of external fixator. Materials and Methods: 15 patients (7 females, 8 males) were included in this consecutive series. The average age was 18.1 years (range 8–35 years). Fifteen tibiae and one femur were lengthened in 15 patients. Lengthening was achieved at 1 mm/day followed by distal segment fixation with three or four screws on reaching the target length. Results: The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8–6.5 cm). The mean duration of external fixation was 75.3 days (range 33–116 days) with the mean external fixation index at 19.2 days/cm (range 10.0–38.3 days/cm). One patient suffered deep infection up to the plate, three patients had mild procurvatum deformities, and one patient developed mild tendo achilles contracture. Conclusion: Lengthening over a plate allows early removal of external fixator and eliminates the risk of creating deep intramedullary infection as with lengthening over nail. Lengthening over plate is also applicable to children with open physis. PMID:22719123

A systematic approach to magnetic resonance imaging evaluation of epiphyseal lesions.

PubMed

Thawait, Shrey K; Thawait, Gaurav K; Frassica, Frank J; Andreisek, Gustav; Carrino, John A; Chhabra, Avneesh

2013-04-01

Magnetic Resonance Imaging (MRI) is the preferred modality of choice to image epiphyseal lesions. It provides excellent soft tissue resolution and extent of disease. A wide spectrum of tumor and tumor like lesions can involve the epiphysis. Early and accurate diagnosis as well as appropriate management of epiphyseal lesions is critical as these conditions may lead to disabling complications such as, limb length discrepancy, angular or joint surface deformities and secondary osteoarthritis. In this article, we discuss the role of conventional sequences, such as T1W, fluid sensitive T2W and intravenous (IV) Gadolinium enhanced sequences as well as the additional value of problem solving MRI sequences such as, chemical shift and diffusion weighted imaging. Based on the imaging findings on various MRI sequences and lesion characteristics, a systematic approach directed to the diagnoses of epiphyseal lesions is presented and discussed. MRI features of clinically and biopsy proven examples of the epiphyseal lesions, such as osteomyelitis, intra-osseous abscess, infiltrative malignancy, metastases, transient osteoporosis, subchondral insufficiency fracture, avascular necrosis, osteochondral fracture, osteochondritis dissecans, eosinophilic granuloma and geode are demonstrated. Using this systematic approach, the reader will be able to better characterize epiphyseal lesions with a potential to positively affect patient management. Copyright © 2013 Elsevier Inc. All rights reserved.

An evaluation of flexible intramedullary nail fixation in femoral shaft fractures in paediatric age group.

PubMed

Kumar, Sanjay; Roy, Sandip Kumar; Jha, Amrish Kumar; Chatterjee, Debdutta; Banerjee, Debabrata; Garg, Anant Kumar

2011-06-01

Sixty-two femoral shaft fractures in 60 patients treated by elastic intramedullary nailing with mean age of the patients being 9.2 years (range 5 years to 12 years) and average follow-up of 15 months (range 7 months to 60 months) are evaluated. Twenty-eight fractures were fixed with titanium elastic nail while 34 fractures were fixed with Enders nail. There were 40 midshaft fractures, 18 proximal femoral and 4 were fractures of distal third. Fracture patterns were transverse in 35, short oblique in 14 cases and 13 were spiral fractures. Mean age of union in this series was 17 weeks (range 12 weeks to 28 weeks). Ten cases had complications, 5 had nail tip irritation, 3 varus or valgus malalignment and 2 had delayed union. In this series, we did not have any non-union, refracture, limb length discrepancy or any major infection. The result demonstrates 100% union rate irrespective of the age, weight and height of the patient. Regardless of the site of fracture and their pattern, it united every time with elastic nail fixation. We did not find and mismatch in the results of fractures stabilised with titanium elastic nail with that of elastic stainless steel nail.

A glossary of terms to assist the recognition and diagnosis of skin conditions associated with lower-limb chronic oedema.

PubMed

Elwell, Rebecca; Craven, Nicholas

2015-04-01

There are a number of recognised skin conditions associated with chronic oedema, but the lack of agreed definitions and terminology often leads to poor recognition and a delay in treatment. Many patients are given a diagnostic 'label' (e.g. varicose eczema) that often turns out to be incorrect, leading to an interruption in the patient pathway. Every skin condition can be described in a variety of ways and each professional group adheres to certain phrases and words that, within each discipline, are recognised, but when making onward referral or working between professions, it helps to have clear and concise definitions. This article aims is to standardise the terminology used to describe skin conditions of the lower limbs among health professionals, removing some of the discrepancy, and to develop a glossary to aid recognition, definition and hence diagnosis to ensure prompt and appropriate management is implemented.

Allometry and apparent paradoxes in human limb proportions: Implications for scaling factors.

PubMed

Auerbach, Benjamin M; Sylvester, Adam D

2011-03-01

It has been consistently demonstrated that human proximal limb elements exhibit negative allometry, while distal elements scale with positive allometry. Such scaling implies that longer limbs will have higher intralimb indices, a phenomenon not borne out by empirical analyses. This, therefore, creates a paradox within the limb allometry literature. This study shows that these apparently conflicting results are the product of two separate phenomena. First, the use of the geometric mean of limb elements produces allometry coefficients that are not independent, and that when using ordinary least squares regression must yield an average slope of one. This phenomenon argues against using the geometric mean as a size variable when examining limb allometry. While the employment of relevant dimensions independent of those under analysis to calculate the geometric mean--as suggested by Coleman (Am J Phys Anthropol 135 (2008) 404-415)--may be a partial method for resolving the problem, an empirically determined, independent and biologically relevant size variable is advocated. If stature is used instead of the geometric mean as an independent size variable, all major limb elements scale with positive allometry. Second, while limb allometry coefficients do indicate differential allometry in limb elements, and thus should lead to some intralimb index allometry, this pattern appears to be attenuated by other sources of limb element length variation. Copyright © 2010 Wiley-Liss, Inc.

Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles

PubMed Central

Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

2014-01-01

The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm2), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm2). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18–0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the ‘design’ of their functional capability. In addition to improving our understanding of muscle anatomy and function, elucidation of forearm neuromuscular compartments architecture may ultimately provide information useful for selection of muscle subdivisions used in tendon transfer. PMID:24836406

Separating Fact from Fiction: Increasing Running Speed

ERIC Educational Resources Information Center

Murgia, Carla

2008-01-01

From a biomechanical point of view, this article explores the common belief that one must increase stride length and frequency in order to increase running speed. The limb length, explosive power, and anaerobic capacity of the athlete, as well as the type of running (sprinting vs. long distance) must be considered before making such a…

Prediction Equation for Lower Limbs Lean Soft Tissue in Circumpubertal Boys Using Anthropometry and Biological Maturation

PubMed Central

Valente-dos-Santos, João; Coelho-e-Silva, Manuel J.; Machado-Rodrigues, Aristides M.; Elferink-Gemser, Marije T.; Malina, Robert M.; Petroski, Édio L.; Minderico, Cláudia S.; Silva, Analiza M.; Baptista, Fátima; Sardinha, Luís B.

2014-01-01

Lean soft tissue (LST), a surrogate of skeletal muscle mass, is largely limited to appendicular body regions. Simple and accurate methods to estimate lower limbs LST are often used in attempts to partition out the influence of body size on performance outputs. The aim of the current study was to develop and cross-validate a new model to predict lower limbs LST in boys aged 10–13 years, using dual-energy X-ray absorptiometry (DXA) as the reference method. Total body and segmental (lower limbs) composition were assessed with a Hologic Explorer-W QDR DXA scanner in a cross-sectional sample of 75 Portuguese boys (144.8±6.4 cm; 40.2±9.0 kg). Skinfolds were measured at the anterior and posterior mid-thigh, and medial calf. Circumferences were measured at the proximal, mid and distal thigh. Leg length was estimated as stature minus sitting height. Current stature expressed as a percentage of attained predicted mature stature (PMS) was used as an estimate of biological maturity status. Backward proportional allometric models were used to identify the model with the best statistical fit: ln (lower limbs LST)  = 0.838× ln (body mass) +0.476× ln (leg length) – 0.135× ln (mid-thigh circumference) – 0.053× ln (anterior mid-thigh skinfold) – 0.098× ln (medial calf skinfold) – 2.680+0.010× (percentage of attained PMS) (R = 0.95). The obtained equation was cross-validated using the predicted residuals sum of squares statistics (PRESS) method (R 2 PRESS = 0.90). Deming repression analysis between predicted and current lower limbs LST showed a standard error of estimation of 0.52 kg (95% limits of agreement: 0.77 to −1.27 kg). The new model accurately predicts lower limbs LST in circumpubertal boys. PMID:25229472

Discrepancies in reporting the CAG repeat lengths for Huntington's disease

PubMed Central

Quarrell, Oliver W; Handley, Olivia; O'Donovan, Kirsty; Dumoulin, Christine; Ramos-Arroyo, Maria; Biunno, Ida; Bauer, Peter; Kline, Margaret; Landwehrmeyer, G Bernhard

2012-01-01

Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original results from 121 laboratories across 15 countries. We report on 1326 duplicate results; a discrepancy in reporting the upper allele occurred in 51% of cases, this reduced to 13.3% and 9.7% when we applied acceptable measurement errors proposed by the American College of Medical Genetics and the Draft European Best Practice Guidelines, respectively. Duplicate results were available for 1250 lower alleles; discrepancies occurred in 40% of cases. Clinically significant discrepancies occurred in 4.0% of cases with a potential unexplained misdiagnosis rate of 0.3%. There was considerable variation in the discrepancy rate among 10 of the countries participating in this study. Out of 1326 samples, 348 were re-analysed by an accredited diagnostic laboratory, based in Germany, with concordance rates of 93% and 94% for the upper and lower alleles, respectively. This became 100% if the acceptable measurement errors were applied. The central laboratory correctly reported allele sizes for six standard reference samples, blind to the known result. Our study differs from external quality assessment (EQA) schemes in that these are duplicate results obtained from a large sample of patients across the whole diagnostic range. We strongly recommend that laboratories state an error rate for their measurement on the report, participate in EQA schemes and use reference materials regularly to adjust their own internal standards. PMID:21811303

Primary central chondrosarcoma of long bone, limb girdle and trunk: Analysis of 174 cases by numerical scoring on histology.

PubMed

Konishi, Eiichi; Nakashima, Yasuaki; Mano, Masayuki; Tomita, Yasuhiko; Nagasaki, Ikumitsu; Kubo, Toshikazu; Araki, Nobuhito; Haga, Hironori; Toguchida, Junya; Ueda, Takafumi; Sakuma, Toshiko; Imahori, Masaya; Morii, Eiichi; Yoshikawa, Hideki; Tsukamoto, Yoshitane; Futani, Hiroyuki; Wakasa, Kenichi; Hoshi, Manabu; Hamada, Shinshichi; Takeshita, Hideyuki; Inoue, Takeshi; Aono, Masanari; Kawabata, Kenji; Murata, Hiroaki; Katsura, Kanade; Urata, Yoji; Ueda, Hideki; Yanagisawa, Akio

2015-09-01

The aims of this study were: (i) to elucidate clinicopathological characteristics of pcCHS of long bones (L), limb girdles (LG) and trunk (T) in Japan; (ii) to investigate predictive pathological findings for outcome of pcCHS of L, LG and T, objectively; and (iii) to elucidate a discrepancy of grade between biopsy and resected specimens. Clinicopathological profiles of 174 pcCHS (79 male, 95 female), of L, LG, and T were retrieved. For each case, a numerical score was given to 18 pathological findings. The average age was 50.5 years (15-80 years). Frequently involved sites were femur, humerus, pelvis and rib. The 5-year and 10-year disease-specific survival (DSS) rates [follow-up: 1-258 months (average 65.5)] were 87.0% and 80.4%, respectively. By Cox hazards analysis on pathological findings, age, sex and location, histologically higher grade and older age were unfavorable predictors, and calcification was a favorable predictor in DSS. The histological grade of resected specimen was higher than that of biopsy in 37.7% (26/69 cases). In conclusion, higher histological grade and older age were predictors for poor, but calcification was for good prognosis. Because there was a discrepancy in grade between biopsy and resected specimens, comprehensive evaluation is necessary before definitive operation for pcCHS. © 2015 The Authors. Pathology International published by Japanese Society of Pathology and Wiley Publishing Asia Pty Ltd.

Achondroplasia and limb lengthening: Results in a UK cohort and review of the literature

PubMed Central

Donaldson, James; Aftab, Syed; Bradish, Christopher

2015-01-01

Aims We aim to review the results, complications and outcomes of a single surgeon's series of lower limb lengthening in patients with achondroplasia. Methods Ten achondroplastic children underwent limb lengthening. The patients, medical records and radiographs were reviewed. Results The average age at the time of the index operation was 7.8 years. A single surgeon undertook all procedures. The average total length gain was 20.5 cm. The commonest complication was a fractured femur after removal of the frame. Conclusion Although complication rates were high (70%), none were left with any long-term sequelae and all were pleased with the results. PMID:25829758

[Treatment of pediatric distal femur fractures by external fixator combined with limited internal fixation].

PubMed

Wei, Sheng-wang; Shi, Zhan-ying; Hu, Ju-zheng; Wu, Hao

2016-03-01

To discuss the clinical effects of external fixator combined with limited internal fixation in the treatment of pediatric distal femur fractures. From January 2008 to June 2014, 17 children of distal femur fractures were treated by external fixator combined with limited internal fixation. There were 12 males and 5 females, aged from 6 to 13 years old with an average of 10.2 years, ranged in the course of disease from 1 h to 2 d. Preoperative diagnoses were confirmed by X-ray films in all children. There were 11 patients with supracondylar fracture , and 6 patients with intercondylar comminuted fracture. According to AO/ASIF classification, 9 fractures were type A1, 5 cases were type A2,and 3 cases were type C1. The intraoperative and postoperative complications, postoperative radiological examination, lower limbs length and motion of knee joints were observed. Knee joint function was assessed by KSS score. All the patients were followed up from 6 to 38 months with an average of 24.4 months. No nerve or blood vessel injury was found. One case complicated with the external fixation loosening, 2 cases with the infection of pin hole and 3 cases with the leg length discrepancy. Knee joint mobility and length measurement (compared with the contralateral), the average limited inflexion was 10 degrees (0 degrees to 20 degrees), the average limited straight was 4 degrees (0 degrees to 10), the average varus or valgus angle was 3 degrees (0 degrees to 5 degrees). KSS of the injured side was (96.4 +/- 5.0) points at final follow-up, 16 cases got excellent results and 1 good. All fractures obtained healing and no epiphyseal closed early was found. External fixator combined with limited internal fixation has advantages of simple operation, reliable fixation, early functional exercise in treating pediatric distal femurs fractures.

The Relationship of Explicit-Implicit Evaluative Discrepancy to Exercise Dropout in Middle-Aged Adults.

PubMed

Berry, Tanya R; Rodgers, Wendy M; Divine, Alison; Hall, Craig

2018-06-19

Discrepancies between automatically activated associations (i.e., implicit evaluations) and explicit evaluations of motives (measured with a questionnaire) could lead to greater information processing to resolve discrepancies or self-regulatory failures that may affect behavior. This research examined the relationship of health and appearance exercise-related explicit-implicit evaluative discrepancies, the interaction between implicit and explicit evaluations, and the combined value of explicit and implicit evaluations (i.e., the summed scores) to dropout from a yearlong exercise program. Participants (N = 253) completed implicit health and appearance measures and explicit health and appearance motives at baseline, prior to starting the exercise program. The sum of implicit and explicit appearance measures was positively related to weeks in the program, and discrepancy between the implicit and explicit health measures was negatively related to length of time in the program. Implicit exercise evaluations and their relationships to oft-cited motives such as appearance and health may inform exercise dropout.

Long-Term Global Morphology of Gravity Wave Activity Using UARS Data

NASA Technical Reports Server (NTRS)

Eckermann, Stephen D.; Jackman, Charles H. (Technical Monitor)

2000-01-01

This report provides a broad outline of the total body of research conducted during the past three years. We report on detailed model studies of the precise way in which infrared limb scanning satellites explicitly detect gravity waves, and use these insights to resolve earlier discrepant zonal mean estimates of gravity wave variances from satellite limb scanners. Detailed analysis of CRISTA temperature fluctuations are outlined, which provide new global information on long-wavelength stratospheric gravity waves generated by mountains, tropical convection and the mid-latitude jet stream- vortex system, as well as interactions higher in the mesosphere with the diurnal tide. The detailed insights gained from analyzing CRISTA data are applied to provide a multi- year analysis of stratospheric mountain waves over the Andes evident in MLS limb-track data. We also demonstrate for the first time that stratospheric temperature data from the CLAES instrument on UARS resolved gravity waves, and we highlight mountain wave information in a subset of these data. Final conclusions and recommendations are set forth, and the present findings are directly related to the original goals of the research contract. A full list of publications that resulted from this research is provided.

Long-Term Global Morphology of Gravity Wave Activity Using UARS Data

NASA Technical Reports Server (NTRS)

Eckermann, Stephen D.

2000-01-01

This report provides a broad outline of the total body of research conducted during the past three years. We report on detailed model studies of the precise way in which infrared limb scanning satellites explicitly detect gravity waves, and use these insights to resolve earlier discrepant zonal mean estimates of gravity wave variances from satellite limb scanners. Detailed analysis of CRISTA temperature fluctuations are outlined, which provide new global information on long-wavelength stratospheric gravity waves generated by mountains, tropical convection and the mid-latitude jet stream-vortex system, as well as interactions higher in the mesosphere with the diurnal tide. The detailed insights gained from analyzing CRISTA data are applied to provide a multiyear analysis of stratospheric mountain waves over the Andes evident in MLS limb-track data. We also demonstrate for the first time that stratospheric temperature data from the CLAES instrument on UARS resolved gravity waves, and we highlight mountain wave information in a subset of these data. Final conclusions and recommendations are set forth, and the present findings are directly related to the original goals of the research contract. A full list of publications that resulted from this research is provided.

Major lower extremity lawn mower injuries in children.

PubMed

Dormans, J P; Azzoni, M; Davidson, R S; Drummond, D S

1995-01-01

Between 1983 and 1993, 16 children with 18 lower extremity power lawn mower-related injuries were treated at Children's Hospital of Philadelphia. Eleven of 16 patients (69%) were bystanders or nonoperators. The average age at injury was 4 years 9 months. Length of follow-up averaged 3 years 10 months. There was an average of 4.9 procedures per patient. Fourteen of the 18 limbs injured required eventual amputation (78%). We propose a new classification of lawn mower injuries in children. The most common injury (16 of 18 limbs) was a shredding type injury and was either intercalary or distal. The second was a paucilaceration type (two of 18 limbs). Of the four salvaged limbs, there were two shredding type injuries, and on most recent follow-up are considered to have poor results. The two patients with the paucilaceration type injuries and limb salvage are considered to have excellent results. All patients with a shredding type injury ultimately required amputation or had poor results with the salvaged limb. Limb salvage surgery was associated with prolonged hospitalizations, a higher incidence of surgical problems, a longer treatment course, and more complications than early ablative procedures.

Design and preliminary evaluation of an exoskeleton for upper limb resistance training

NASA Astrophysics Data System (ADS)

Wu, Tzong-Ming; Chen, Dar-Zen

2012-06-01

Resistance training is a popular form of exercise recommended by national health organizations, such as the American College of Sports Medicine (ACSM) and the American Heart Association (AHA). This form of training is available for most populations. A compact design of upper limb exoskeleton mechanism for homebased resistance training using a spring-loaded upper limb exoskeleton with a three degree-of-freedom shoulder joint and a one degree-of-freedom elbow joint allows a patient or a healthy individual to move the upper limb with multiple joints in different planes. It can continuously increase the resistance by adjusting the spring length to train additional muscle groups and reduce the number of potential injuries to upper limb joints caused by the mass moment of inertia of the training equipment. The aim of this research is to perform a preliminary evaluation of the designed function by adopting an appropriate motion analysis system and experimental design to verify our prototype of the exoskeleton and determine the optimal configuration of the spring-loaded upper limb exoskeleton.

Temperature regulates limb length in homeotherms by directly modulating cartilage growth

PubMed Central

Serrat, Maria A.; King, Donna; Lovejoy, C. Owen

2008-01-01

Allen's Rule documents a century-old biological observation that strong positive correlations exist among latitude, ambient temperature, and limb length in mammals. Although genetic selection for thermoregulatory adaptation is frequently presumed to be the primary basis of this phenomenon, important but frequently overlooked research has shown that appendage outgrowth is also markedly influenced by environmental temperature. Alteration of limb blood flow via vasoconstriction/vasodilation is the current default hypothesis for this growth plasticity, but here we show that tissue perfusion does not fully account for differences in extremity elongation in mice. We show that peripheral tissue temperature closely reflects housing temperature in vivo, and we demonstrate that chondrocyte proliferation and extracellular matrix volume strongly correlate with tissue temperature in metatarsals cultured without vasculature in vitro. Taken together, these data suggest that vasomotor changes likely modulate extremity growth indirectly, via their effects on appendage temperature, rather than vascular nutrient delivery. When combined with classic evolutionary theory, especially genetic assimilation, these results provide a potentially comprehensive explanation of Allen's Rule, and may substantially impact our understanding of phenotypic variation in living and extinct mammals, including humans. PMID:19047632

In-series compliance of gastrocnemius muscle in cat step cycle: do spindles signal origin-to-insertion length?

PubMed Central

Elek, J; Prochazka, A; Hulliger, M; Vincent, S

1990-01-01

1. It has been claimed that stretch in the non-contractile (extramysial) portion of muscles is substantial, and may produce large discrepancies between the origin-to-insertion muscle length and the internal length variations 'seen' by muscle spindle endings. 2. In eight pentobarbitone-anaesthetized cats, we estimated stretch in the extramysial portion of medial gastrocnemius (MG) muscle with a method similar to the spindle null technique. 3. Length variations of MG previously monitored in a normal step cycle were reproduced with a computer-controlled length servo. The responses of test MG spindle endings were monitored in dorsal root filaments. Distributed stimulation of ventral root filaments, rate-modulated by the step-cycle EMG envelope, served to reproduce step-cycle forces. The filaments were selected so as to have no fusimotor action on the test spindle. 4. Spindle responses in active cycles were compared with those in passive cycles (stretch, but no distributed stimulation). In some cases concomitant tonic fusimotor stimulation was used to maintain spindle responsiveness throughout the cycle, both in active and passive trials. Generally, small discrepancies in spindle firing were seen. The passive trials were now repeated, with iterative adjustments of the length function, until the response matched the spindle firing profile in the active trial. The spindle 'saw' the same internal length change in the final passive trial as in the active trial. Any difference between the corresponding length profiles was attributed to extramysial displacement. 5. Extramysial displacement estimated in this was was maximal at short mean muscle lengths, reaching about 0.5 mm in a typical step cycle (force rising from 0 to 10 N). At longer mean muscle lengths where muscle force rose from say 2 to 12 N in the cycle, extramysial displacement was in the range 0.2-0.4 mm. 6. Except at very short lengths, the displacement was probably mainly tendinous. On this assumption, our results suggested that the stiffness of the MG tendinous compartment was force related, and about double that of cat soleus muscle at any given force. Calculations indicated that though the stretch was small, the MG tendon would store and release enough strain energy per cycle to contribute significantly to the E3 phase of the step cycle. The discrepancies in spindle firing were generally quite subtle, so we reject the claim that extramysial stretch poses a serious difficulty for inferences about fusimotion from chronic spindle afferent recordings. PMID:2148952

Functional anatomy of the cheetah (Acinonyx jubatus) forelimb

PubMed Central

Hudson, Penny E; Corr, Sandra A; Payne-Davis, Rachel C; Clancy, Sinead N; Lane, Emily; Wilson, Alan M

2011-01-01

Despite the cheetah being the fastest living land mammal, we know remarkably little about how it attains such high top speeds (29 m s−1). Here we aim to describe and quantify the musculoskeletal anatomy of the cheetah forelimb and compare it to the racing greyhound, an animal of similar mass, but which can only attain a top speed of 17 m s−1. Measurements were made of muscle mass, fascicle length and moment arms, enabling calculations of muscle volume, physiological cross-sectional area (PCSA), and estimates of joint torques and rotational velocities. Bone lengths, masses and mid-shaft cross-sectional areas were also measured. Several species differences were observed and have been discussed, such as the long fibred serratus ventralis muscle in the cheetah, which we theorise may translate the scapula along the rib cage (as has been observed in domestic cats), thereby increasing the cheetah's effective limb length. The cheetah's proximal limb contained many large PCSA muscles with long moment arms, suggesting that this limb is resisting large ground reaction force joint torques and therefore is not functioning as a simple strut. Its structure may also reflect a need for control and stabilisation during the high-speed manoeuvring in hunting. The large digital flexors and extensors observed in the cheetah forelimb may be used to dig the digits into the ground, aiding with traction when galloping and manoeuvring. PMID:21332715

Problems with Excessive Residual Lower Leg Length in Pediatric Amputees

PubMed Central

Osebold, William R; Lester, Edward L; Christenson, Donald M

2001-01-01

We studied six pediatric amputees with long below-knee residual limbs, in order to delineate their functional and prosthetic situations, specifically in relation to problems with fitting for dynamic-response prosthetic feet. Three patients had congenital pseudoarthrosis of the tibia secondary to neurofibromatosis, one had fibular hemimelia, one had a traumatic amputation, and one had amputation secondary to burns. Five patients had Syme's amputations, one had a Boyd amputation. Ages at amputation ranged from nine months to five years (average age 3 years 1 month). After amputation, the long residual below-knee limbs allowed fitting with only the lowest-profile prostheses, such as deflection plates. In three patients, the femoral dome to tibial plafond length was greater on the amputated side than on the normal side. To allow room for more dynamic-response (and larger) foot prostheses, two patients have undergone proximal and distal tibial-fibular epiphyseodeses (one at age 5 years 10 months, the other at 3 years 7 months) and one had a proximal tibial-fibular epiphyseodesis at age 7 years 10 months. (All three patients are still skeletally immature.) The families of two other patients are considering epiphyseodeses, and one patient is not a candidate (skeletally mature). Scanogram data indicate that at skeletal maturity the epiphyseodesed patients will have adequate length distal to their residual limbs to fit larger and more dynamic-response prosthetic feet. PMID:11813953

STUDY OF THE 3D GEOMETRIC STRUCTURE AND TEMPERATURE OF A CORONAL CAVITY USING THE LIMB SYNOPTIC MAP METHOD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karna, N.; Pesnell, W. Dean; Webber, S. A. Hess

2015-09-10

We present the three-dimensional geometric structure and thermal properties of a coronal cavity deduced from limb synoptic maps. The observations are extreme ultraviolet images from the Atmospheric Imager Assembly (AIA) and magnetic images from the Helioseismic Magnetic Imager instruments on board the Solar Dynamics Observatory. We describe a limb synoptic-map method used to effectively identify and measure cavities from annuli of radiance above the solar limb. We find that cavities are best seen in the 211, 193, and 171 Å passbands. The prominence associated with each cavity is best seen in the 304 Å synoptic maps. We also estimate themore » thermal properties of the cavity and surrounding plasma by combining the AIA radiances with a differential emission measure analysis. This paper focuses on one long cavity from a catalog of coronal cavities that we are developing. Cavities in this catalog are designated by a coded name using the Carrington Rotation number and position. Cavity C211347177N was observed during Carrington Rotation 2113 at the northwestern limb of the solar disk with an average latitude of 47° N and a central longitude of 177°. We showed the following. (1) The cavity is a long tube with an elliptical cross-section with ratios of the length to width and the length to height of 11:1 and 7:1, respectively. (2) The cavity is about 1360 Mm long, or 170° in longitude. (3) It is tilted in latitude. (4) And it is slightly hotter than its surroundings.« less

Dealing with time-varying recruitment and length in Hill-type muscle models.

PubMed

Hamouda, Ahmed; Kenney, Laurence; Howard, David

2016-10-03

Hill-type muscle models are often used in muscle simulation studies and also in the design and virtual prototyping of functional electrical stimulation systems. These models have to behave in a sufficiently realistic manner when recruitment level and contractile element (CE) length change continuously. For this reason, most previous models have used instantaneous CE length in the muscle׳s force vs. length (F-L) relationship, but thereby neglect the instability problem on the descending limb (i.e. region of negative slope) of the F-L relationship. Ideally CE length at initial recruitment should be used but this requires a multiple-motor-unit muscle model to properly account for different motor-units having different initial lengths when recruited. None of the multiple-motor-unit models reported in the literature have used initial CE length in the muscle׳s F-L relationship, thereby also neglecting the descending limb instability problem. To address the problem of muscle modelling for continuously varying recruitment and length, and hence different values of initial CE length for different motor-units, a new multiple-motor-unit muscle model is presented which considers the muscle to comprise 1000 individual Hill-type virtual motor-units, which determine the total isometric force. Other parts of the model (F-V relationship and passive elements) are not dependent on the initial CE length and, therefore, they are implemented for the muscle as a whole rather than for the individual motor-units. The results demonstrate the potential errors introduced by using a single-motor-unit model and also the instantaneous CE length in the F-L relationship, both of which are common in FES control studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of computer-assisted surgery with conventional technique for the treatment of axial distal phalanx fractures in horses: an in vitro study.

PubMed

Andritzky, Juliane; Rossol, Melanie; Lischer, Christoph; Auer, Joerg A

2005-01-01

To compare the precision obtained with computer-assisted screw insertion for treatment of mid-sagittal articular fractures of the distal phalanx (P3) with results achieved with a conventional technique. In vitro experimental study. Thirty-two cadaveric equine limbs. Four groups of 8 limbs were studied. Either 1 or 2 screws were inserted perpendicular to an imaginary axial fracture of P3 using computer-assisted surgery (CAS) or conventional technique. Screw insertion time, predetermined screw length, inserted screw length, fit of the screw, and errors in placement were recorded. CAS technique took 15-20 minutes longer but resulted in greater precision of screw length and placement compared with the conventional technique. Improved precision in screw insertion with CAS makes insertion of 2 screws possible for repair of mid-sagittal P3 fractures. CAS although expensive improves precision in screw insertion into P3 and consequently should yield improved clinical outcome.

A case of Bockenheimer's syndrome (genuine diffuse phlebectasia): venous involvement inside muscles was detected by magnetic resonance imaging.

PubMed

Osawa, R; Kato, N; Yanagi, T; Yamane, N

2007-11-01

We report a 13-year-old girl with an extensive bluish phlebectasia of the upper right arm and right side of the chest, which had been present since birth. There was no difference in length between the right (affected) and left (healthy) limbs, but the involved limb was thicker than the noninvolved limb. Magnetic resonance imaging showed distended veins with slow blood flow under the skin of the right limb. The veins inside the muscles of forearm were also involved. Histological examination of the bluish lesions revealed large phlebectasia showing distended veins without any proliferation of endothelial cells. The amount of elastin in the walls of these veins was decreased. The patient was diagnosed with Bockenheimer's syndrome. The characteristics of this rare syndrome are indicated and discussed.

Crouch gait can be an effective form of forced-use/no constraint exercise for the paretic lower limb in stroke.

PubMed

Tesio, Luigi; Rota, Viviana; Malloggi, Chiara; Brugliera, Luigia; Catino, Luigi

2017-09-01

In hemiplegic gait the paretic lower limb provides less muscle power and shows a briefer stance compared with the unaffected limb. Yet, a longer stance and a higher power can be obtained from the paretic lower limb if gait speed is increased. This supports the existence of a 'learned non-use' phenomenon, similar to that underlying some asymmetric impairments of the motion of the eyes and of the upper limbs. Crouch gait (CG) (bent-hip bent-knee, about 30° minimum knee flexion) might be an effective form of 'forced-use' treatment of the paretic lower limb. It is not known whether it also stimulates a more symmetric muscle power output. Gait analysis on a force treadmill was carried out in 12 healthy adults and seven hemiplegic patients (1-127 months after stroke, median: 1.6). Speed was imposed at 0.3 m/s. Step length and single and double stance times, sagittal joint rotations, peak positive power, and work in extension of the hip, knee, and ankle (plantar flexion), and surface electromyography (sEMG) area from extensor muscles during the generation of power were measured on either side during both erect and crouch walking. Significance was set at P less than 0.05; corrections for multiplicity were applied. Patients, compared with healthy controls, adopted in both gait modalities and on both sides a shorter step length (61-84%) as well as a shorter stance (76-90%) and swing (63-83%) time. As a rule, they also provided a higher muscular work (median: 137%, range: 77-250%) paralleled by a greater sEMG area (median: 174%, range: 75-185%). In erect gait, the generation of peak extensor power across hip, knee, and ankle joints was in general lower (83-90%) from the paretic limb and higher (98-165%) from the unaffected limb compared with control values. In CG, peak power generation across the three lower limb joints was invariably higher in hemiparetic patients: 107-177% from the paretic limb and 114-231% from the unaffected limb. When gait shifted from erect to crouch, only for hemiplegic patients, at the hip, the paretic/unaffected ratio increased significantly. For peak power, work, sEMG area, and joint rotation, the paretic/unaffected ratio increased from 55 to 85%, 56 to 72%, 68 to 91%, and 67 to 93%, respectively. CG appears to be an effective form of forced-use exercise eliciting more power and work from the paretic lower limb muscles sustained by a greater neural drive. It also seems effective in forcing a more symmetric power and work from the hip extensor muscles, but neither from the knee nor the ankle.

Knee arthodesis using a modular customized intramedullary nail.

PubMed

Letartre, R; Combes, A; Autissier, G; Bonnevialle, N; Gougeon, F

2009-11-01

Arthrodesis of the knee, particularly in infectious situations, can be achieved using either an external fixator or an intramedullary device. The objective of this study is to report the clinical, functional, and radiographic outcomes of a continuous series of 19 cases of knee arthrodesis using a customized modular intramedullary nailing system. The modular intramedullary nail offers a satisfactory functional result while maintaining limb length, in spite of a nonunion risk, since acting like a true endoprosthesis. In our retrospective series of 19 patients, the main source of patients were infected total knee replacements. The nail was customized from assembling a dual surface-sanded titanium component (femoral and tibial). The Lequesne Algofunctional score and the WOMAC score were recorded, as well as the length discrepancy between the lower extremities. Arthrodesis consolidation and the nail's fit in the shaft were verified on anterior-posterior (AP) and lateral radiographs. Five complications were observed: one anterior cortical break, one excessive tibial rotation, two cases of delayed union, and one nail revision due to residual nail instability. The postoperative Lequesne Algofunctional score was 13/24 and the WOMAC score 57/100. The nonunion rate was 32%. From a functional point of view, the patients who did not achieve complete union and those who did had similar scores. The subjective results were not as good in patients who did not achieve final consolidation. Modular intramedullary nailing simplifies the technique, shortens the procedure, and reduces the amount of blood loss at surgery. Our nonunion rate was high, although the functional result did not seem compromised by such nonunion. The risk of long-term implant failure was not studied and requires longer follow-up studies. Level IV therapeutic study. 2009 Published by Elsevier Masson SAS.

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy.

PubMed

Allet, Lara; Kim, Hogene; Ashton-Miller, James; De Mott, Trina; Richardson, James K

2014-01-01

Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Injured subjects demonstrated greater extreme step length changes after medial perturbation than non-injured subjects (percent change = 18.5 ± 9.2 vs. 11.3 ± 4.57; p = .01). The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter which distinguishes between subjects sustaining a fall-related injury and those who did not. © 2014.

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy

PubMed Central

Allet, L; Kim, H; Ashton-Miller, JA; De Mott, T; Richardson, JK

2013-01-01

Aims Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Methods Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Results Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Fallers demonstrated greater extreme step length changes after medial perturbation than non fallers (percent change = 16.41±8.42 vs 11.0±4.95; p=.06) Conclusions The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter, which distinguishes between fallers and non fallers. PMID:24183899

The usefulness of Duplex Doppler ultrasound in the angiological and dermatological diagnosis of patients with blue toe syndrome.

PubMed

Pawlaczyk, Katarzyna; Gabriel, Marcin; Strzelecka-Węklar, Daria A; Krasiński, Zbigniew; Stanisic, Michal; Gabriel, Zofia; Dzieciuchowicz, Łukasz; Adamski, Zygmunt

2017-10-01

Peripheral microembolism is one of the most frequent causes of acute limb ischemia. In order to effectively prevent relapses it is essential to localize and eliminate the source of embolism. To evaluate the role of Duplex Doppler ultrasound examination in identifying the causes of blue toe syndrome (BTS). The group of 165 patients with clinical symptoms of BTS on their upper limbs ( n = 16) and lower limbs ( n = 149) was investigated. They all underwent Duplex Doppler ultrasound of the major arteries of the extremities, where ischemic changes occurred. Morphological and functional changes which might be potential sources of microembolism were identified in 146 patients. These changes included significant short-length stenoses or unstable atherosclerotic plaque ( n = 73), true aneurysms ( n = 42) and pseudoaneurysms ( n = 17). In 11 cases, pathology of vascular prostheses in the form of anastomotic aneurysms, infection and residual thrombi after fibrinolysis was detected. In all cases, Duplex diagnosis was confirmed by other imaging and intraoperative tests. Duplex Doppler ultrasound of the arteries in the affected limb with a full length view should be the first-line examination in diagnosing patients with BTS. In the absence of hemodynamic blood flow disturbances in the major arteries in patients with symptoms of BTS, it is advisable to start haematological tests to identify/exclude congenital or acquired thrombophilia.

Can the contralateral limb be used as a control during the growing period in a rodent model?

PubMed

Mustafy, Tanvir; Londono, Irène; Villemure, Isabelle

2018-05-12

The contralateral limb is often used as a control in various clinical, forensic and anthropological studies. However, no studies have been performed to determine if the contra-lateral limb is a suitable control during the bone development period. The aim of this study was to determine the bilateral symmetry of growing rat tibiae in terms of geometric shape, mechanical strength and bone morphological parameters with developmental stages. Left and right tibias of 18 male Sprague-Dawley rats at 4, 8 and 12 weeks of age were scanned with micro-CT for bone-morphometric evaluation and for 3D deviation analysis to quantify the geometric shape variations between left and right tibiae. Overall tibial lengths and curvatures were also measured, and bone mechanical strength was investigated using three-point bending tests. Deviation distributions between bilateral tibiae remained below 0.5 mm for more than 80% of the geometry for all groups. Tibial lengths, longitudinal tibial curvatures, bone-morphometric parameters and mechanical strengths changed significantly during the growing period but kept a strong degree of symmetry between bilateral tibiae. These results suggest that bilateral tibiae can be considered symmetrical in nature and that contralateral limb can be used as a control during the growing period in different experimental scenarios. Copyright © 2018 Elsevier Ltd. All rights reserved.

Resurrection of the in situ saphenous vein bypass. 1000 cases later.

PubMed Central

Leather, R P; Shah, D M; Chang, B B; Kaufman, J L

1988-01-01

Distal bypasses for the terminal stages of atherosclerotic occlusive disease manifest by chronic limb-threatening ischemia are among the most challenging arterial reconstructive procedures of surgeons today. The length and low flow rates of distal bypasses often exceed the functional limits of synthetic and even free vein grafts. However, the saphenous vein, when used in situ, provides a unique, viable, physiologically active, and hence antithrombogenic endothelial flow surface that is ideally suited for such bypasses. This paper presents the experience of the Albany Medical Center Hospital with the first 1000 in situ bypasses performed by the valve incision method over a 12-year period. Limb-threatening ischemia was the most common indication for surgery (91%). An in situ bypass was attempted in over 95% of unselected limbs and were completed in situ and in toto in 94%. 66% of the bypasses were carried out to the infrapopliteal level, and in more than 50% of the limbs, the distal vein diameter was less than 3.5 mm. The 30-day patency rate was 95%, and the cumulative patency rates, by life table analysis at 1, 2, 3, 4, and 5 years, were 90%, 86%, 84%, 80%, and 76%, respectively. The vein diameter, specific outflow vessel, level of distal anastomosis (length of bypass), inguinal inflow source used, and instrumental evolution had no significant effect on immediate or long-term bypass performance. PMID:3178331

Active control stabilization of pelvic position in the transverse plane: an evaluation of soccer players' performance.

PubMed

Santos, Thiago Ribeiro Teles; Andrade, Juliana Alves de; Silva, Bárbara Lopes da; Garcia, Alysson Francisco Alves; Persichini Filho, José Gaspar Wild; Ocarino, Juliana de Melo; Silva, Paula Lanna

2014-08-01

To describe the capability of soccer players to stabilize pelvic position actively in the transverse plane; and, to evaluate the influence of lower limb dominance, length of exposure to soccer practice, and field position on pelvic stabilization capability. Cross-sectional. Sixty-eight soccer players from under-15 (U-15) and professional categories. Magnitude and asymmetry of pelvic tilt in the transverse plane, evaluated using the bridge test with unilateral knee extension. The magnitude of pelvic tilt did not differ between dominant and non-dominant sides, suggesting absence of relative asymmetry. However, there was difference between the sides of greater and lesser magnitude of pelvic tilt, indicating presence of absolute asymmetry. Players with shorter length of exposure to soccer practice (U-15 group) had greater pelvic tilt than players with longer length of exposure (professional group). There was no association of field position with the magnitude and asymmetry of pelvic tilt. Soccer players showed asymmetry in pelvic stabilization capability that was unrelated to lower limb dominance or field position. Athletes with longer length of exposure to soccer practice present better capability to stabilize the pelvis in the transverse plane than those with shorter length of exposure to soccer practice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tendon length and joint flexibility are related to running economy.

PubMed

Hunter, Gary R; Katsoulis, Konstantina; McCarthy, John P; Ogard, William K; Bamman, Marcas M; Wood, David S; Den Hollander, Jan A; Blaudeau, Tamilane E; Newcomer, Bradley R

2011-08-01

The purpose of study was to determine whether quadriceps/patella and Achilles tendon length and flexibility of the knee extensors and plantar flexors are related to walking and running economy. Twenty-one male distance runners were subjects. Quadriceps/patella and Achilles tendon length were measured by magnetic resonance imaging; body composition was measured DXA; oxygen uptake at rest while seated, walking (3 mph), and running (6 and 7 mph) were measured by indirect calorimetry; knee and ankle joint flexibility were measured by goniometry; and leg lengths were measured by anthropometry while seated. Correlations were used to identify relationships between variables of interest. Net VO2 (exercise VO2 - rest VO2) for walking (NVOWK) and running at 6 and 7 mph (NVO6 and NVO7, respectively) was significantly related to Achilles tendon length (r varying from -0.40 to -0.51, P all < 0.04). Achilles tendon cross section was not related to walking or running economy. Quadriceps/patella tendon length was significantly related to NVO7 (r = -0.43, P = 0.03) and approached significance for NVO6 (r = -0.36, P = 0.06). Flexibility of the plantar flexors was related to NVO7 (+0.38, P = 0.05). Multiple regression showed that Achilles tendon length was independently related to NVO6 and NVO7 (partial r varying from -0.53 to -0.64, all P < 0.02) independent of lower leg length, upper leg length, quadriceps/patella tendon length, knee extension flexibility, or plantarflexion flexibility. These data support the premise that longer lower limb tendons (especially Achilles tendon) and less flexible lower limb joints are associated with improved running economy.

Fibularis tertius: revisiting the anatomy.

PubMed

Rourke, K; Dafydd, H; Parkin, I G

2007-11-01

Fibularis tertius (FT) may be used during reconstructive surgery and muscle transposition with retention of function. The muscle was examined in both lower limbs of 41 cadavers. Measurements were made of muscle belly length and width, tendon length and width, and the size of the origin on the fibula. Tendon insertion, nerve and blood supplies were also examined. FT was absent in five (6.1%) lower limbs of three (7.3%) subjects. The size of its origin demonstrated inter- and intra-individual variation. FT arose from the distal fibula and on average occupied (28.4 +/- 9.1)% (mean +/- S. D.) of the total shaft length. In all cases the tendon inserted into the dorsal surface of the shafts of both the fourth and fifth metatarsals. A small nerve branch consistently arose from the deep fibular nerve near the origin of extensor digitorum longus. The nerve ran parallel to the length of this muscle, between it and extensor hallucis longus, before piercing FT. Anatomy textbooks describe FT as inserting into the fifth metatarsal only. This study, supported by data from previous reports, suggests that the "textbook" accounts of FT should be updated to record that most commonly its tendon reaches both the fourth and fifth metatarsals.

Functional leg length discrepancy between theories and reliable instrumental assessment: a study about newly invented NPoS system.

PubMed

Mahmoud, Asmaa; Abundo, Paolo; Basile, Luisanna; Albensi, Caterina; Marasco, Morena; Bellizzi, Letizia; Galasso, Franco; Foti, Calogero

2017-01-01

In spite the instinct social&financial impact of Leg Length Discrepancy (LLD), controversial and conflicting results still exist regarding a reliable assessment/correction method. For proper management it's essential to discriminate between anatomical&functional Leg Length Discrepancy (FLLD). With the newly invented NPoS (New Postural Solution), under the umbrella of the collaboration of PRM Department, Tor Vergata University with Baro Postural Instruments srl, positive results were observed in both measuring& compensating the hemi-pelvic antero-medial rotation in FLLD through personalized bilateral heel raise using two NPoS components: Foot Image System (FIS) and Postural Optimizer System (POS). This led our research interest to test the validity of NPoS as a preliminary step before evaluating its implementations in postural disorders. After clinical evaluation, 4 subjects with FLLD have been assessed by NPoS. Over a period of 2 months, every subject was evaluated 12 times by two different operators, 48 measurements in total, results have been verified in correlation to BTS GaitLab results. Intra-Operator&inter-operator variability analysis showed statistically insignificant differences, while inter-method variability between NPoS and BTS parameters expressed a linear correlation. Results suggest a significant validity of NPoS in assessment&correction of FLLD, with high degree of reproducibility with minimal operator dependency. This can be considered a base for promising clinical implications of NPoS as a reliable cost effective postural assessment/corrective tool. V.

Birth dimensions in Melanesian and Indian Fijians and their relationships with maternal and socio-economic factors.

PubMed

Clegg, E J; Clegg, S D

1989-01-01

Fifty-nine Melanesian (MF) and 39 Indian (IF) Fijian full-term newborns were studied within 5 days of birth. Dimensions recorded included birthweight, length, crown-rump length, head circumference, upper limb length, bycondylar humeral and femoral diameters and four skinfolds (triceps, subscapular, suprailiac and thigh). Data from previous pregnancies of the presenting newborns' mothers were added to presenting birthweights, giving a total of 160 MF and 84 IF birthweights. In all birthweight and linear dimensions MFs were the bigger. Sex differences were significant in respect only of head circumference and the two bicondylar diameters. Multiple regression analysis showed dimensions in MF newborns to have few significant relationships with the maternal and socio-economic variables of age, parity, stature and years of education, but IFs had many more significant relationships. When covariance correction was made for the significant maternal and socio-economic variables (maternal age and parity) little effect on racial differences was seen. All linear dimensions except length could be subsumed into birthweight. MFs had greater triceps and subscapular skinfold thicknesses than IFs, a difference which was not much changed by covariance correction for significant maternal and socio-economic variables (maternal stature and years of education). Measurements of shape, expressed as ratios of linear dimensions, showed few racial differences but males had relatively broader limbs. For upper limb shape only, this difference was maintained after covariance correction for significant maternal and socio-economic variables (parity, stature and education). The greater size of MF infants at birth is associated with lower peri- and neonatal death rates. However this advantage is reversed during the remainder of the first year of life. It is suggested that better standards of infant care among IFs are responsible for this change.

[Repetitive movement of the upper limbs: results of exposure evaluation and clinical investigation during jar packaging of preserved vegetables].

PubMed

Panzone, I; Carra, G; Melosi, A; Rappazzo, G; Innocenti, A

1996-01-01

In order to assess the prevalence of work-related musculo-skeletal disorders of the upper limbs, a total population of 29 female workers in an industrial vegetable preserving plant were examined. The average age of the workers was 41.3 years (SD = 9.2), and their average length of service was 16.7 years (SD = 7.2). Only 20% of the workers were anamnestically negative, whilst 80% had one or more disorders attributable to repetitive trauma of the upper limbs. The disorders showed no prevalence for the right side, a finding in line with the risk analysis which indicated that both limbs were equally used. The results of the risk analysis and clinical assessment confirm that high-frequency actions, combined with improper posture and a shortage of suitable recovery times, play a causal role in determining the onset of the disorders studied.

Ambulant adults with spastic cerebral palsy: the validity of lower limb joint angle measurements from sagittal video recordings.

PubMed

Larsen, Kerstin L; Maanum, Grethe; Frøslie, Kathrine F; Jahnsen, Reidun

2012-02-01

In the development of a clinical program for ambulant adults with cerebral palsy (CP), we investigated the validity of joint angles measured from sagittal video recordings and explored if movements in the transversal plane identified with three-dimensional gait analysis (3DGA) affected the validity of sagittal video joint angle measurements. Ten observers, and 10 persons with spastic CP (19-63 years), Gross Motor Function Classification System I-II, participated in the study. Concurrent criterion validity between video joint angle measurements and 3DGA was assessed by Bland-Altman plots with mean differences and 95% limits of agreement (LoA). Pearson's correlation coefficients (r) and scatter plots were used supplementary. Transversal kinematics ≥2 SD from our reference band were defined as increased movement in the transversal plane. The overall mean differences in degrees between joint angles measured by 3DGA and video recordings (3°, 5° and -7° for the hip, knee and ankle respectively) and corresponding LoA (18°, 10° and 15° for the hip, knee and ankle, respectively) demonstrated substantial discrepancies between the two methods. The correlations ranged from low (r=0.39) to moderate (r=0.68). Discrepancy between the two measurements was seen both among persons with and without the presence of deviating transversal kinematics. Quantifying lower limb joint angles from sagittal video recordings in ambulant adults with spastic CP demonstrated low validity, and should be conducted with caution. This gives implications for selecting evaluation method of gait. Copyright © 2011 Elsevier B.V. All rights reserved.

Reconstructive procedures for segmental resection of bone in giant cell tumors around the knee.

PubMed

Aggarwal, Aditya N; Jain, Anil K; Kumar, Sudhir; Dhammi, Ish K; Prashad, Bhagwat

2007-04-01

Segmental resection of bone in Giant Cell Tumor (GCT) around the knee, in indicated cases, leaves a gap which requires a complex reconstructive procedure. The present study analyzes various reconstructive procedures in terms of morbidity and various complications encountered. Thirteen cases (M-six and F-seven; lower end femur-six and upper end tibia -seven) of GCT around the knee, radiologically either Campanacci Grade II, Grade II with pathological fracture or Grade III were included. Mean age was 25.6 years (range 19-30 years). Resection arthrodesis with telescoping (shortening) over intramedullary nail (n=5), resection arthrodesis with an intercalary allograft threaded over a long intramedullary nail (n=3) and resection arthrodesis with intercalary fibular autograft and simultaneous limb lengthening (n=5) were the procedure performed. Shortening was the major problem following resection arthrodesis with telescoping (shortening) over intramedullary nail. Only two patients agreed for subsequent limb lengthening. The rest continued to walk with shortening. Infection was the major problem in all cases of resection arthrodesis with an intercalary allograft threaded over a long intramedullary nail and required multiple drainage procedures. Fusion was achieved after two years in two patients. In the third patient the allograft sequestrated. The patient underwent sequestrectomy, telescoping of fragments and ilizarov fixator application with subsequent limb lengthening. The patient was finally given an ischial weight relieving orthosis, 54 months after the index procedure. After resection arthrodesis with intercalary autograft and simultaneous lengthening the resultant gap (∼15cm) was partially bridged by intercalary nonvascularized dual fibular strut graft (6-7cm) and additional corticocancellous bone graft from ipsilateral patella. Simultaneous limb lengthening with a distal tibial corticotomy was performed on an ilizarov fixator. The complications were superficial infection (n=5), stress fracture of fibula (n=2). The stress fracture fibula required DCP fixation and bone grafting. The usual time taken for union and limb length equalization was approximately one year. Resection arthrodesis with intercalary dual fibular autograft and cortico-cancellous bone grafting with simultaneous limb lengthening achieved limb length equalization with relatively short morbidity.

Making Better Lives: Patient-Focused Care for Low Back Pain (LBP)

ClinicalTrials.gov

2018-03-26

Chronic Low Back Pain; Hip Ostearthritis; Myofascial Pain Syndrome; Fibromyalgia; Depression; Maladaptive Coping; Lumbar Spinal Stenosis; Insomnia; Sacroiliac Joint Pain; Lateral Hip and Thigh Pain; Anxiety; Dementia; Recent Leg Length Discrepancy

Sonic Hedgehog Signaling in Limb Development

PubMed Central

Tickle, Cheryll; Towers, Matthew

2017-01-01

The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs. PMID:28293554

The Effect of Virtual Reality Distraction on Pain Relief During Dressing Changes in Children with Chronic Wounds on Lower Limbs.

PubMed

Hua, Yun; Qiu, Rong; Yao, Wen-Yan; Zhang, Qin; Chen, Xiao-Li

2015-10-01

It has been demonstrated that patients with chronic wounds experience the most pain during dressing changes. Currently, researchers focus mostly on analgesics and appropriate dressing materials to relieve pain during dressing changes of chronic wounds. However, the effect of nonpharmacologic interventions, such as virtual reality distraction, on pain management during dressing changes of pediatric chronic wounds remains poorly understood. To investigate the effect of virtual reality distraction on alleviating pain during dressing changes in children with chronic wounds on their lower limbs. A prospective randomized study. A pediatric center in a tertiary hospital. Sixty-five children, aged from 4 to 16 years, with chronic wounds on their lower limbs. Pain and anxiety scores during dressing changes were recorded by using the Wong-Baker Faces picture scale, visual analogue scale, and pain behavior scale, as well as physiological measurements including pulse rate and oxygen saturation. Time length of dressing change was recorded. Virtual reality distraction significantly relieved pain and anxiety scores during dressing changes and reduced the time length for dressing changes as compared to standard distraction methods. The use of virtual reality as a distraction tool in a pediatric ward offered superior pain reduction to children as compared to standard distractions. This device can potentially improve clinical efficiency by reducing length time for dressing changes. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Functional anatomy of the cheetah (Acinonyx jubatus) forelimb.

PubMed

Hudson, Penny E; Corr, Sandra A; Payne-Davis, Rachel C; Clancy, Sinead N; Lane, Emily; Wilson, Alan M

2011-04-01

Despite the cheetah being the fastest living land mammal, we know remarkably little about how it attains such high top speeds (29 m s(-1)). Here we aim to describe and quantify the musculoskeletal anatomy of the cheetah forelimb and compare it to the racing greyhound, an animal of similar mass, but which can only attain a top speed of 17 m s(-1). Measurements were made of muscle mass, fascicle length and moment arms, enabling calculations of muscle volume, physiological cross-sectional area (PCSA), and estimates of joint torques and rotational velocities. Bone lengths, masses and mid-shaft cross-sectional areas were also measured. Several species differences were observed and have been discussed, such as the long fibred serratus ventralis muscle in the cheetah, which we theorise may translate the scapula along the rib cage (as has been observed in domestic cats), thereby increasing the cheetah's effective limb length. The cheetah's proximal limb contained many large PCSA muscles with long moment arms, suggesting that this limb is resisting large ground reaction force joint torques and therefore is not functioning as a simple strut. Its structure may also reflect a need for control and stabilisation during the high-speed manoeuvring in hunting. The large digital flexors and extensors observed in the cheetah forelimb may be used to dig the digits into the ground, aiding with traction when galloping and manoeuvring. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.

Limb lengthening in short stature patients.

PubMed

Aldegheri, R; Dall'Oca, C

2001-07-01

A series of 140 patients with short stature operated on for limb lengthening (80 had achondroplasia, 20 had hypochondroplasia, 20 had Turner syndrome, 10 had idiopathic short stature due to an undemonstrated cause, 5 regarded their stature as too short, and 5 had a psychopathic personality due to dysmorphophobia that had developed because of their short stature) was reviewed. All patients underwent symmetric lengthening of both femora and tibiae; 10 of these achondroplastic patients underwent lengthening of the humeri. We carried out the 580 lengthening procedures by means of three different surgical techniques: 440 callotasis, 120 chondrodiatasis and 20 mid-shaft osteotomy. In the 130 patients with a disproportionate short stature, the average gain in length was 18.2 +/- 3.93 cm: 43.8% had complications and 3.8% had sequelae; the average treatment time was 31 months. In the 10 patients with proportionate short stature, the average gain in length was 10.8 +/- 1.00 cm: 4 experienced complications and none had sequelae; the average treatment time was 21 months. Patients who underwent lengthening of the upper limbs experienced an average gain in length of 10.2 +/- 1.25 cm: the average treatment time was 9 months and none of them experienced any complications or sequelae. The authors discuss how difficult it is to achieve the benefits of this surgery: they underline the strong commitment on the part of the patients and their families, the time in the hospital, the number of operations and, above all, the severity of those permanent sequelae that occurred.

Effect of Full-Length Carbon Fiber Insoles on Lower Limb Kinetics in Patients With Midfoot Osteoarthritis: A Pilot Study.

PubMed

Yi, Taeim; Kim, Jung Hyun; Oh-Park, Mooyeon; Hwang, Ji Hye

2018-03-01

We investigated the effects of full-length carbon fiber (FCF) insoles on gait, muscle activity, kinetics, and pain in patients with midfoot osteoarthritis (OA). We enrolled 13 patients with unilateral midfoot OA (mild: Visual Analog Scale [VAS] range, 1-3; moderate, VAS range, 4-7) and healthy controls. All participants were asked to walk under two conditions: with and without FCF insole. The outcome measures were ground reaction force, quantitative gait parameters, electromyography activities and pain severity (VAS). In the patients with moderate midfoot OA, significantly longer gait cycle and higher muscle activity of lower limb during loading-response phase were observed while walking without FCF insoles. In the mild midfoot OA group, there was no significant difference in VAS score (without, 2.0 ± 1.0 vs. with, 2.0 ± 0.5) with FCF insole use. However, significantly reduced VAS score (without, 5.5 ± 1.4 vs. with, 2.0 ± 0.5) and muscle activity of the tibialis anterior and increased muscle activity of gastrocnemius were observed in the moderate midfoot OA group by using an FCF insole (P < 0.05). Full-length carbon fiber insoles can improve pain in individuals with moderate midfoot OA, which might be associated with changes in the kinetics and muscle activities of the lower limb. Taken together, the results of the present study suggest that FCF insoles may be used as a helpful option for midfoot OA.

Addressing Systematic Errors in Correlation Tracking on HMI Magnetograms

NASA Astrophysics Data System (ADS)

Mahajan, Sushant S.; Hathaway, David H.; Munoz-Jaramillo, Andres; Martens, Petrus C.

2017-08-01

Correlation tracking in solar magnetograms is an effective method to measure the differential rotation and meridional flow on the solar surface. However, since the tracking accuracy required to successfully measure meridional flow is very high, small systematic errors have a noticeable impact on measured meridional flow profiles. Additionally, the uncertainties of this kind of measurements have been historically underestimated, leading to controversy regarding flow profiles at high latitudes extracted from measurements which are unreliable near the solar limb.Here we present a set of systematic errors we have identified (and potential solutions), including bias caused by physical pixel sizes, center-to-limb systematics, and discrepancies between measurements performed using different time intervals. We have developed numerical techniques to get rid of these systematic errors and in the process improve the accuracy of the measurements by an order of magnitude.We also present a detailed analysis of uncertainties in these measurements using synthetic magnetograms and the quantification of an upper limit below which meridional flow measurements cannot be trusted as a function of latitude.

The comparative anatomy of the forelimb veins of primates.

PubMed Central

Thiranagama, R; Chamberlain, A T; Wood, B A

1989-01-01

One hundred and thirteen forelimbs taken from 62 individuals belonging to 17 primate genera were dissected to reveal the entire course of the superficial venous system. The course of the deep venous system was also documented in at least one forelimb of each primate genus, and the number and location of perforating veins was recorded in 18 human and 45 non-human primate limbs. In Pan, Gorilla and in about 25% of human specimens the lateral superficial vein was confined to the forearm, while in all other primates, and in the majority of humans, this vein extended from the carpus to the clavicular region. Only Pongo and humans exhibited a second main superficial vein on the medial side of the forearm. In all primates the deep veins of the forelimb usually accompanied the arteries. Thus variation in the deep venous system reflected the different arterial patterns exhibited by these primates. The number of perforating veins in the forelimb was related to the length of the limb. Primate genera with longer forelimbs had more perforators, though not as many as would be expected if the number of perforators scaled linearly with limb length. PMID:2514175

Crouch gait can be an effective form of forced-use/no constraint exercise for the paretic lower limb in stroke

PubMed Central

Rota, Viviana; Malloggi, Chiara; Brugliera, Luigia; Catino, Luigi

2017-01-01

In hemiplegic gait the paretic lower limb provides less muscle power and shows a briefer stance compared with the unaffected limb. Yet, a longer stance and a higher power can be obtained from the paretic lower limb if gait speed is increased. This supports the existence of a ‘learned non-use’ phenomenon, similar to that underlying some asymmetric impairments of the motion of the eyes and of the upper limbs. Crouch gait (CG) (bent-hip bent-knee, about 30° minimum knee flexion) might be an effective form of ‘forced-use’ treatment of the paretic lower limb. It is not known whether it also stimulates a more symmetric muscle power output. Gait analysis on a force treadmill was carried out in 12 healthy adults and seven hemiplegic patients (1–127 months after stroke, median: 1.6). Speed was imposed at 0.3 m/s. Step length and single and double stance times, sagittal joint rotations, peak positive power, and work in extension of the hip, knee, and ankle (plantar flexion), and surface electromyography (sEMG) area from extensor muscles during the generation of power were measured on either side during both erect and crouch walking. Significance was set at P less than 0.05; corrections for multiplicity were applied. Patients, compared with healthy controls, adopted in both gait modalities and on both sides a shorter step length (61–84%) as well as a shorter stance (76–90%) and swing (63–83%) time. As a rule, they also provided a higher muscular work (median: 137%, range: 77–250%) paralleled by a greater sEMG area (median: 174%, range: 75–185%). In erect gait, the generation of peak extensor power across hip, knee, and ankle joints was in general lower (83–90%) from the paretic limb and higher (98–165%) from the unaffected limb compared with control values. In CG, peak power generation across the three lower limb joints was invariably higher in hemiparetic patients: 107–177% from the paretic limb and 114–231% from the unaffected limb. When gait shifted from erect to crouch, only for hemiplegic patients, at the hip, the paretic/unaffected ratio increased significantly. For peak power, work, sEMG area, and joint rotation, the paretic/unaffected ratio increased from 55 to 85%, 56 to 72%, 68 to 91%, and 67 to 93%, respectively. CG appears to be an effective form of forced-use exercise eliciting more power and work from the paretic lower limb muscles sustained by a greater neural drive. It also seems effective in forcing a more symmetric power and work from the hip extensor muscles, but neither from the knee nor the ankle. PMID:28574860

Limb-darkening coefficients for the purpose of pulsation mode identification for A-F stars. .

NASA Astrophysics Data System (ADS)

Barban, C.; Goupil, M. J.; van't Veer-Menneret, C.; Garrido, R.; Heiter, U.; Kupka, F.

Limb-darkening coefficients are computed from a set of model atmospheres with: a solar chemical composition, 6000 K< Teff < 8500 K (Delta T_eff=250 K), 2.5 < logg < 4.5 (Delta log g=0.1) and a microturbulent velocity of 2 km/s. Convection is included assuming either the turbulent convection approach of \\citet{cm} or the classical mixing length prescription with alpha =0.5 and 1.25. Four limb-darkening laws have been used: quadratic, cubic, square root and the one of \\citet{cl}. We compare the ATLAS 9 intensities and the ones computed from these laws. We find that Claret's law is the best law for almost all the models, independently of the convection prescription used.

Arthrodesis in septic knees using a long intramedullary nail: 17 consecutive cases.

PubMed

Leroux, B; Aparicio, G; Fontanin, N; Ohl, X; Madi, K; Dehoux, E; Diallo, S

2013-06-01

Intramedullary nailing using long or modular nails is the most reliable mean of achieving femorotibial fusion. Here, we report the operative, clinical, functional, and radiological outcomes of 17 long intramedullary nail arthodeses in patients with infection. Clinical and functional outcomes after long intramedullary nailing are at least as good as those obtained using other implants. We retrospectively reevaluated 17 patients after unilateral two-stage knee arthrodesis with a long titanium intramedullary nail and autologous bone grafting. We evaluated satisfaction, leg length discrepancy, and function (Lequesne and WOMAC indices). Radiographs were obtained to assess fusion, time to fusion, and femorotibial angles. No cases of material failure were recorded. One or more complications occurred in seven patients. Mean limb shortening was 27.6mm. Of the 17 patients, 15 were satisfied with the procedure. The mean Lequesne index was 10.5/24 and the mean overall WOMAC score was 26/88. Fusion was achieved in 16 patients, with a mean time to fusion of 5 months. Mean femorotibial angles were 178.6° of varus and 1.9° of flexion. This simple and rapid surgical technique provides functional outcomes similar to those obtained using modular nails. The fusion rate is high. Nail extraction is simple and causes minimal damage, in contrast to modular nails. Increased attention to misalignment is needed. Level IV, retrospective study. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Sport injuries: a review of outcomes.

PubMed

Maffulli, Nicola; Longo, Umile Giuseppe; Gougoulias, Nikolaos; Caine, Dennis; Denaro, Vincenzo

2011-01-01

Injuries can counter the beneficial aspects related to sports activities if an athlete is unable to continue to participate because of residual effects of injury. We provide an updated synthesis of existing clinical evidence of long-term follow-up outcome of sports injuries. A systematic computerized literature search was conducted on following databases were accessed: PubMed, Medline, Cochrane, CINAHL and Embase databases. At a young age, injury to the physis can result in limb deformities and leg-length discrepancy. Weight-bearing joints including the hip, knee and ankle are at risk of developing osteoarthritis (OA) in former athletes, after injury or in the presence of malalignment, especially in association with high impact sport. Knee injury is a risk factor for OA. Ankle ligament injuries in athletes result in incomplete recovery (up to 40% at 6 months), and OA in the long term (latency period more than 25 years). Spine pathologies are associated more commonly with certain sports (e.g. wrestling, heavy-weight lifting, gymnastics, tennis, soccer). Evolution in arthroscopy allows more accurate assessment of hip, ankle, shoulder, elbow and wrist intra-articular post-traumatic pathologies, and possibly more successful management. Few well-conducted studies are available to establish the long-term follow-up of former athletes. To assess whether benefits from sports participation outweigh the risks, future research should involve questionnaires regarding the health-related quality of life in former athletes, to be compared with the general population.

Fixator-assisted medial tibial plateau elevation to treat severe Blount's disease: outcomes at maturity.

PubMed

Fitoussi, F; Ilharreborde, B; Lefevre, Y; Souchet, P; Presedo, A; Mazda, K; Penneçot, G F

2011-04-01

Severe forms of Blount's disease may be associated with medial tibial plateau (MTP) depression. Management should then take account of joint congruence, laxity, limb axis, torsional abnomality, leg length discrepancy (LLD) and eventual recurrence history. Eight knees (six patients) were managed in a single step comprising MTP elevation osteotomy, lateral epiphysiodesis and proximal tibia osteotomy to correct varus and rotational deformity. Fixation was achieved using an Ilizarov external fixator. Mean age was 10.5 years. Mean hip-knee-ankle (HKA) angle was 151°; distal femoral varus, 94°; metaphyseal-diaphyseal angle (MDA), 27°; and angle of depression of the medial tibial plateau (ADMTP), 42°. Predicted residual proximal tibial growth was 2.6 cm. At a mean 48 months' follow-up, results were good in six cases, medium in one and poor (due to incomplete lateral epiphysiodesis) in one. Mean lateral tibial torsion was 9° and final LLD 11 mm. Weight-bearing was resumed at 2 months, and the fixator was removed at 5.5 months postoperatively. At end of follow-up, mean HKA angle was 179.6°, MDA 7.3° and ADMTP 5.4°. This technically demanding procedure gave satisfactory results in terms of axes and congruence; longer term assessment remains needed. Level IV. Retrospective study. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

The effects of altering initial ground contact in the running gait of an individual with transtibial amputation.

PubMed

Waetjen, Linda; Parker, Matthew; Wilken, Jason M

2012-09-01

High rates of osteoarthritis of the knee joint of the intact limb in persons with amputation have raised concern about the long-term consequence of running. The purpose of this intervention was to determine if loading of the knee on the intact limb of a person with transtibial amputation during running could be decreased by changing the intact limb initial ground contact from rear foot to forefoot strike. This study compared kinematic, kinetic and temporal-spatial data collected while a 27-year-old male, who sustained a traumatic unilateral transtibial amputation of the left lower extremity, ran using a forefoot ground contact and again while using a heel first ground contact. Changing initial ground contact from rear foot strike to forefoot strike resulted in decreases in vertical ground reaction forces at impact, peak knee moments in stance, peak knee powers, and improved symmetry in step length. This case suggests forefoot initial contact of the intact limb may minimize loading of the knee on the intact limb in individuals with transtibial amputation.

Influence of training on the biokinematics in trotting Andalusian horses.

PubMed

Cano, M R; Miró, F; Diz, A M; Agüera, E; Galisteo, A M

2000-11-01

The aim of this study was to determine the influence of a 10-month training programme on the linear, temporal and angular characteristics of the fore and hind limbs at the trot in the Andalusian horse, using standard computer-aided videography. Sixteen male Andalusian horses were observed before and after training. Six strides were randomly selected for analysis in each horse and linear, temporal and angular parameters were calculated for fore and hind limbs. The training programme used here produced significant changes in kinematic parameters, such as shortening of stride length, and increase in swing duration and a decrease in hind limb stance percentage. No significant differences were recorded in the angular values for the forelimb joints. In trained horses, the more proximal joints of the hind limb, especially the hip and stifle, had a greater flexion while the fetlock showed a smaller extension angle. At the beginning of the swing phase, hip and stifle joints presented angles that were significantly more flexed. When the hind limbs came into contact with the ground, all the joints presented greater flexion after training.

Concomitant upper limb fractures and short-term functional recovery in hip fracture patients: does the site of upper limb injury matter?

PubMed

Di Monaco, Marco; Castiglioni, Carlotta; Vallero, Fulvia; Di Monaco, Roberto; Tappero, Rosa

2015-05-01

The aim of this study was to evaluate functional recovery in a subgroup of hip fracture patients who sustained a simultaneous fracture at the upper limb, taking into account the site of upper limb injury. Of 760 patients admitted consecutively to the authors' rehabilitation hospital because of a fall-related hip fracture, 700 were retrospectively investigated. Functional outcome was assessed using Barthel Index scores. In 49 of the 700 patients, a single fall resulted in both a hip fracture and a fracture of either wrist (n = 34) or proximal humerus (n = 15). The patients with concomitant shoulder fractures had lower median Barthel Index scores after rehabilitation (70 vs. 90, P = 0.003), lower median Barthel Index effectiveness (57.1 vs. 76.9, P = 0.018), and prolonged median length of stay (42 vs. 36 days, P = 0.011) than did the patients with isolated hip fractures. Significant differences persisted after adjustment for six potential confounders. The adjusted odds ratio for achieving a Barthel Index score lower than 85 was 6.71 (95% confidence interval, 1.68-26.81; P = 0.007) for the patients with concomitant shoulder fractures. Conversely, no prognostic disadvantages were associated with concomitant wrist fractures. Data show a worse functional recovery and a prolonged length of stay in the subgroup of hip fracture patients who sustained a concomitant fracture at the proximal humerus, but not at the wrist.

Comparison of Model and Observations of Middle Atmospheric HOx Response to Solar 27-day Cycles: Quantifying Model Uncertainties due to Photochemistry

NASA Astrophysics Data System (ADS)

Wang, S.; Li, K. F.; Shia, R. L.; Yung, Y. L.; Sander, S. P.

2016-12-01

HO2 and OH (known as odd oxygen HOx), play an important role in middle atmospheric chemistry, in particular, O3 destruction through catalytic HOx reaction cycles. Due to their photochemical production and short chemical lifetimes, HOx species response rapidly to solar UV irradiance changes during solar cycles, resulting in variability in the corresponding O3 chemistry. Observational evidences for both OH and HO2 variability due to solar cycles have been reported. However, puzzling discrepancies remain. In particular, the large discrepancy between model and observations of solar 11-year cycle signal in OH and the significantly different model results when adopting different solar spectral irradiance (SSI) [Wang et al., 2013] suggest that both uncertainties in SSI variability and uncertainties in our current understanding of HOx-O3 chemistry could contribute to the discrepancy. Since the short-term SSI variability (e.g. changes during solar 27-day cycles) has little uncertainty, investigating 27-day solar cycle signals in HOx allows us to simplify the complex problem and to focus on the uncertainties in chemistry alone. We use the Caltech-JPL photochemical model to simulate observed HOx variability during 27-day cycles. The comparison between Aura Microwave Limb Sounder (MLS) observations and our model results (using standard chemistry and "adjusted chemistry", respectively) will be discussed. A better understanding of uncertainties in chemistry will eventually help us separate the contribution of chemistry from contributions of SSI uncertainties to the complex discrepancy between model and observations of OH responses to solar 11-year cycles.

Whole limb kinematics are preferentially conserved over individual joint kinematics after peripheral nerve injury

PubMed Central

Chang, Young-Hui; Auyang, Arick G.; Scholz, John P.; Nichols, T. Richard

2009-01-01

Summary Biomechanics and neurophysiology studies suggest whole limb function to be an important locomotor control parameter. Inverted pendulum and mass-spring models greatly reduce the complexity of the legs and predict the dynamics of locomotion, but do not address how numerous limb elements are coordinated to achieve such simple behavior. As a first step, we hypothesized whole limb kinematics were of primary importance and would be preferentially conserved over individual joint kinematics after neuromuscular injury. We used a well-established peripheral nerve injury model of cat ankle extensor muscles to generate two experimental injury groups with a predictable time course of temporary paralysis followed by complete muscle self-reinnervation. Mean trajectories of individual joint kinematics were altered as a result of deficits after injury. By contrast, mean trajectories of limb orientation and limb length remained largely invariant across all animals, even with paralyzed ankle extensor muscles, suggesting changes in mean joint angles were coordinated as part of a long-term compensation strategy to minimize change in whole limb kinematics. Furthermore, at each measurement stage (pre-injury, paralytic and self-reinnervated) step-by-step variance of individual joint kinematics was always significantly greater than that of limb orientation. Our results suggest joint angle combinations are coordinated and selected to stabilize whole limb kinematics against short-term natural step-by-step deviations as well as long-term, pathological deviations created by injury. This may represent a fundamental compensation principle allowing animals to adapt to changing conditions with minimal effect on overall locomotor function. PMID:19837893

Genetic Interactions Between Shox2 and Hox Genes During the Regional Growth and Development of the Mouse Limb

PubMed Central

Neufeld, Stanley J.; Wang, Fan; Cobb, John

2014-01-01

The growth and development of the vertebrate limb relies on homeobox genes of the Hox and Shox families, with their independent mutation often giving dose-dependent effects. Here we investigate whether Shox2 and Hox genes function together during mouse limb development by modulating their relative dosage and examining the limb for nonadditive effects on growth. Using double mRNA fluorescence in situ hybridization (FISH) in single embryos, we first show that Shox2 and Hox genes have associated spatial expression dynamics, with Shox2 expression restricted to the proximal limb along with Hoxd9 and Hoxa11 expression, juxtaposing the distal expression of Hoxa13 and Hoxd13. By generating mice with all possible dosage combinations of mutant Shox2 alleles and HoxA/D cluster deletions, we then show that their coordinated proximal limb expression is critical to generate normally proportioned limb segments. These epistatic interactions tune limb length, where Shox2 underexpression enhances, and Shox2 overexpression suppresses, Hox-mutant phenotypes. Disruption of either Shox2 or Hox genes leads to a similar reduction in Runx2 expression in the developing humerus, suggesting their concerted action drives cartilage maturation during normal development. While we furthermore provide evidence that Hox gene function influences Shox2 expression, this regulation is limited in extent and is unlikely on its own to be a major explanation for their genetic interaction. Given the similar effect of human SHOX mutations on regional limb growth, Shox and Hox genes may generally function as genetic interaction partners during the growth and development of the proximal vertebrate limb. PMID:25217052

Genetic interactions between Shox2 and Hox genes during the regional growth and development of the mouse limb.

PubMed

Neufeld, Stanley J; Wang, Fan; Cobb, John

2014-11-01

The growth and development of the vertebrate limb relies on homeobox genes of the Hox and Shox families, with their independent mutation often giving dose-dependent effects. Here we investigate whether Shox2 and Hox genes function together during mouse limb development by modulating their relative dosage and examining the limb for nonadditive effects on growth. Using double mRNA fluorescence in situ hybridization (FISH) in single embryos, we first show that Shox2 and Hox genes have associated spatial expression dynamics, with Shox2 expression restricted to the proximal limb along with Hoxd9 and Hoxa11 expression, juxtaposing the distal expression of Hoxa13 and Hoxd13. By generating mice with all possible dosage combinations of mutant Shox2 alleles and HoxA/D cluster deletions, we then show that their coordinated proximal limb expression is critical to generate normally proportioned limb segments. These epistatic interactions tune limb length, where Shox2 underexpression enhances, and Shox2 overexpression suppresses, Hox-mutant phenotypes. Disruption of either Shox2 or Hox genes leads to a similar reduction in Runx2 expression in the developing humerus, suggesting their concerted action drives cartilage maturation during normal development. While we furthermore provide evidence that Hox gene function influences Shox2 expression, this regulation is limited in extent and is unlikely on its own to be a major explanation for their genetic interaction. Given the similar effect of human SHOX mutations on regional limb growth, Shox and Hox genes may generally function as genetic interaction partners during the growth and development of the proximal vertebrate limb. Copyright © 2014 by the Genetics Society of America.

Functional leg length discrepancy between theories and reliable instrumental assessment: a study about newly invented NPoS system

PubMed Central

Mahmoud, Asmaa; Abundo, Paolo; Basile, Luisanna; Albensi, Caterina; Marasco, Morena; Bellizzi, Letizia; Galasso, Franco; Foti, Calogero

2017-01-01

Summary Background In spite the instinct social&financial impact of Leg Length Discrepancy (LLD), controversial and conflicting results still exist regarding a reliable assessment/correction method. For proper management it’s essential to discriminate between anatomical&functional Leg Length Discrepancy (FLLD). With the newly invented NPoS (New Postural Solution), under the umbrella of the collaboration of PRM Department, Tor Vergata University with Baro Postural Instruments srl, positive results were observed in both measuring& compensating the hemi-pelvic antero-medial rotation in FLLD through personalized bilateral heel raise using two NPoS components: Foot Image System (FIS) and Postural Optimizer System (POS). This led our research interest to test the validity of NPoS as a preliminary step before evaluating its implementations in postural disorders. Methods After clinical evaluation, 4 subjects with FLLD have been assessed by NPoS. Over a period of 2 months, every subject was evaluated 12 times by two different operators, 48 measurements in total, results have been verified in correlation to BTS GaitLab results. Results Intra-Operator&inter-operator variability analysis showed statistically insignificant differences, while inter-method variability between NPoS and BTS parameters expressed a linear correlation. Conclusion Results suggest a significant validity of NPoS in assessment&correction of FLLD, with high degree of reproducibility with minimal operator dependency. This can be considered a base for promising clinical implications of NPoS as a reliable cost effective postural assessment/corrective tool. Level of evidence V. PMID:29264341

Biomechanical response to ankle-foot orthosis stiffness during running.

PubMed

Russell Esposito, Elizabeth; Choi, Harmony S; Owens, Johnny G; Blanck, Ryan V; Wilken, Jason M

2015-12-01

The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is an ankle-foot orthosis developed to address the high rates of delayed amputation in the military. Its use has enabled many wounded Service Members to run again. During running, stiffness is thought to influence an orthosis' energy storage and return mechanical properties. This study examined the effect of orthosis stiffness on running biomechanics in patients with lower limb impairments who had undergone unilateral limb salvage. Ten patients with lower limb impairments underwent gait analysis at a self-selected running velocity. 1. Nominal (clinically-prescribed), 2. Stiff (20% stiffer than nominal), and 3. Compliant (20% less stiff than nominal) ankle-foot orthosis stiffnesses were tested. Ankle joint stiffness was greatest in the stiffest strut and lowest in the compliant strut, however ankle mechanical work remained unchanged. Speed, stride length, cycle time, joint angles, moments, powers, and ground reaction forces were not significantly different among stiffness conditions. Ankle joint kinematics and ankle, knee and hip kinetics were different between limbs. Ankle power, in particular, was lower in the injured limb. Ankle-foot orthosis stiffness affected ankle joint stiffness but did not influence other biomechanical parameters of running in individuals with unilateral limb salvage. Foot strike asymmetries may have influenced the kinetics of running. Therefore, a range of stiffness may be clinically appropriate when prescribing ankle-foot orthoses for active individuals with limb salvage. Published by Elsevier Ltd.

Prediction of stemless humeral implant micromotion during upper limb activities.

PubMed

Favre, Philippe; Henderson, Adam D

2016-07-01

Adequate primary stability is essential for the long term success of uncemented stemless shoulder implants. The goal of this study was to evaluate the micromotion of a stemless humeral implant during various upper limb activities. A finite element model was validated by reproducing experimental primary stability testing. Loading from an instrumented prosthesis representing a set of 29 upper limb activities were applied within the validated FE model. Peak micromotion and percentage area for different micromotion thresholds were considered. In all simulated activities, at least 99% of the implant surface experienced micromotion below 150μm. Micromotion depended strongly on loading with large discrepancies between upper limb activities. Carrying no external weight and keeping the arm at lower angles induced lower micromotion. Activities representative of demanding manual labor generally led to higher micromotion. Axilla crutches led to lower micromotion than forearm crutches. Micromotion increased when a wheelchair was used on slopes above 2% inclination. Micromotions below the 150μm threshold below which bone ingrowth occurs were measured over at least 99% of the implant surface for all simulated activities. Peak micromotion dependence on activity type demonstrates the need to consider physiologic in vivo loading and the full contact interface in primary stability evaluations. Focusing on activities with no hand weight and low arm motions during the rehabilitation period may enhance primary stability. For patients unable to walk without aids, axilla crutches and motorized wheelchairs might be more beneficial than forearm crutches and manual drive wheelchairs respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evidence of a significant rotational non-LTE effect in the CO2 4.3 µm PFS-MEX limb spectra

NASA Astrophysics Data System (ADS)

Kutepov, Alexander A.; Rezac, Ladislav; Feofilov, Artem G.

2017-01-01

Since January 2004, the planetary Fourier spectrometer (PFS) on board the Mars Express satellite has been recording near-infrared limb spectra of high quality up to the tangent altitudes ≈ 150 km, with potential information on density and thermal structure of the upper Martian atmosphere. We present first results of our modeling of the PFS short wavelength channel (SWC) daytime limb spectra for the altitude region above 90 km. We applied a ro-vibrational non-LTE model based on the stellar astrophysics technique of accelerated lambda iteration (ALI) to solve the multi-species and multi-level CO2 problem in the Martian atmosphere. We show that the long-standing discrepancy between observed and calculated spectra in the cores and wings of 4.3 µm region is explained by the non-thermal rotational distribution of molecules in the upper vibrational states 10011 and 10012 of the CO2 main isotope second hot (SH) bands above 90 km altitude. The redistribution of SH band intensities from band branch cores into their wings is caused (a) by intensive production of the CO2 molecules in rotational states with j > 30 due to the absorption of solar radiation in optically thin wings of 2.7 µm bands and (b) by a short radiative lifetime of excited molecules, which is insufficient at altitudes above 90 km for collisions to maintain rotation of excited molecules thermalized. Implications for developing operational algorithms for massive processing of PFS and other instrument limb observations are discussed.

Limb Correction of Infrared Imagery in Cloudy Regions for the Improved Interpretation of RGB Composites

NASA Technical Reports Server (NTRS)

Elmer, Nicholas J.; Berndt, Emily; Jedlovec, Gary J.

2016-01-01

Red-Green-Blue (RGB) composites (EUMETSAT User Services 2009) combine information from several channels into a single composite image. RGB composites contain the same information as the original channels, but presents the information in a more efficient manner. However, RGB composites derived from infrared imagery of both polar-orbiting and geostationary sensors are adversely affected by the limb effect, which interferes with the qualitative interpretation of RGB composites at large viewing zenith angles. The limb effect, or limb-cooling, is a result of an increase in optical path length of the absorbing atmosphere as viewing zenith angle increases (Goldberg et al. 2001; Joyce et al. 2001; Liu and Weng 2007). As a result, greater atmospheric absorption occurs at the limb, causing the sensor to observe anomalously cooler brightness temperatures. Figure 1 illustrates this effect. In general, limb-cooling results in a 4-11 K decrease in measured brightness temperature (Liu and Weng 2007) depending on the infrared band. For example, water vapor and ozone absorption channels display much larger limb-cooling than infrared window channels. Consequently, RGB composites created from infrared imagery not corrected for limb effects can only be reliably interpreted close to nadir, which reduces the spatial coverage of the available imagery. Elmer (2015) developed a reliable, operational limb correction technique for clear regions. However, many RGB composites are intended to be used and interpreted in cloudy regions, so a limb correction methodology valid for both clear and cloudy regions is needed. This paper presents a limb correction technique valid for both clear and cloudy regions, which is described in Section 2. Section 3 presents several RGB case studies demonstrating the improved functionality of limb-corrected RGBs in both clear and cloudy regions, and Section 4 summarizes and presents the key conclusions of this work.

A nationwide analysis of 30-day readmissions related to critical limb ischemia.

PubMed

Masoomi, Reza; Shah, Zubair; Quint, Clay; Hance, Kirk; Vamanan, Karthik; Prasad, Anand; Hoel, Andrew; Dawn, Buddhadeb; Gupta, Kamal

2018-06-01

Objectives There is paucity of information regarding critical limb ischemia-related readmission rates in patients admitted with critical limb ischemia. We studied 30-day critical limb ischemia-related readmission rate, its predictors, and clinical outcomes using a nationwide real-world dataset. Methods We did a secondary analysis of the 2013 Nationwide Readmissions Database. We included all patients with a primary diagnosis of extremity rest pain, ulceration, and gangrene secondary to peripheral arterial disease. From this group, all patients readmitted with similar diagnosis within 30 days were recorded. Results Of the total 25,111 index hospitalization for critical limb ischemia, 1270 (5%) were readmitted with a primary diagnosis of critical limb ischemia within 30 days. The readmission rate was highest (9.5%) for the group that did not have any intervention (revascularization or major amputation) and was lowest for surgical revascularization and major amputation groups (2.6% and 1.3%, P value <0.001 for all groups). Severity of critical limb ischemia at index admission was associated with a significantly higher rate of 30-day readmission. Critical limb ischemia-related readmission was associated with a higher rate of major amputation (29.6% vs. 16.2%, P<0.001), a lower rate of any revascularization procedure (46% vs. 62.6%, P<0.001), and a higher likelihood of discharge to a skilled nursing facility (43.2% vs. 32.2%, P<0.001) compared to index hospitalization. Conclusions In patients with primary diagnosis of critical limb ischemia, 30-day critical limb ischemia-related readmission rate was affected by initial management strategy and the severity of critical limb ischemia. Readmission was associated with a significantly higher rate of amputation, increased length of stay, and a more frequent discharge to an alternate care facility than index admission and thus may serve as a useful quality of care metric in critical limb ischemia patients.

Electromyogram whitening for improved classification accuracy in upper limb prosthesis control.

PubMed

Liu, Lukai; Liu, Pu; Clancy, Edward A; Scheme, Erik; Englehart

2013-09-01

Time and frequency domain features of the surface electromyogram (EMG) signal acquired from multiple channels have frequently been investigated for use in controlling upper-limb prostheses. A common control method is EMG-based motion classification. We propose the use of EMG signal whitening as a preprocessing step in EMG-based motion classification. Whitening decorrelates the EMG signal and has been shown to be advantageous in other EMG applications including EMG amplitude estimation and EMG-force processing. In a study of ten intact subjects and five amputees with up to 11 motion classes and ten electrode channels, we found that the coefficient of variation of time domain features (mean absolute value, average signal length and normalized zero crossing rate) was significantly reduced due to whitening. When using these features along with autoregressive power spectrum coefficients, whitening added approximately five percentage points to classification accuracy when small window lengths were considered.

Compelled weightbearing in persons with hemiparesis following stroke: the effect of a lift insert and goal-directed balance exercise.

PubMed

Aruin, A S; Hanke, T; Chaudhuri, G; Harvey, R; Rao, N

2000-01-01

The hypotheses have been tested that 1) symmetry of weightbearing in persons who have sustained a stroke could be improved by the addition of a lift to the shoe on the non-paretic lower limb and 2) compelled weightbearing resulting from the addition of a lift in conjunction with targeted exercise helps to overcome the learned disuse of the paretic limb. Weightbearing on the paretic side was measured in eight persons with hemiparesis during quiet standing and in conditions of compelled weight shift. Compelled weight shifts were applied with special lifts to the shoe on the non-paretic limb of the subjects. An increase in symmetrical weightbearing was recorded in conditions of compelled weight shifts: 10-mm lift provided the best symmetry of bipedal standing. We suggest that improved symmetry of bipedal standing obtained with the lift of the non-paretic limb would help in overcoming the learned disuse of the affected limb. Pre- and post-test results of a person with hemiparesis who was wearing a shoe lift on the non-paretic limb during a 6-week physical therapy program showed statistically significant improvement of walking speed, stride length, and weightbearing. Such findings support the idea of using compelled weightbearing via lifting and targeted exercise during treatment.

[Limb lengthening in dwarfism].

PubMed

Correll, J; Held, P

2000-09-01

Limb lengthening in dwarfism has become a standardised procedure with a good prognosis. In most cases external fixation is used. Gain of leg length up to 15 cm and more is possible in the lower leg and the femur and 8.5 cm in the humerus. Limb lengthening is useful in many cases of dwarfism due to skeletal dysplasia. There are a number of risks and possible complications involved and the procedure also requires considerable time. We report the results of 48 patients with dwarfism operated on in the Orthopädische Kinderklinik Aschau (Orthopaedic Hospital for Children). It must not be recommended as a normal tool in handling the problems of dwarfism, but it makes sense in some cases of dwarfism. We describe and discuss the prerequisites for the operative treatment.

Multidisciplinary team approach to residual limb lengthening using the Ilizarov technique: A case study.

PubMed

Savage, Zoliakha; Munjal, Ramesh

2015-10-01

A 47-year-old male suffered a traumatic transtibial amputation; initial limb use was unsuccessful and the short tibial length was thought to be the cause of failure. The patient underwent gradual tibia lengthening using the Ilizarov technique and utilised a weight-bearing prosthesis to expedite bone growth and repair. The patient is now able to use his prosthesis successfully without aids. This case study demonstrates that combining a scientifically based surgical technique with a tailored rehabilitation approach had an improved outcome for the patient. This study reports one case where tibial lengthening using the Ilizarov technique combined with a collaborative team approach has enabled a patient to return to successful prosthetic limb use. © The International Society for Prosthetics and Orthotics 2014.

Mid-term development of hamstring tendon length and velocity after distal femoral extension osteotomy in children with bilateral cerebral palsy: a retrospective cohort study.

PubMed

Salami, Firooz; Wagner, Julia; van Drongelen, Stefan; Klotz, Matthias C M; Dreher, Thomas; Wolf, Sebastian I; Niklasch, Mirjam

2018-03-14

Flexed knee gait can be treated with distal femoral extension osteotomy (DFEO) and additional patellar tendon advancement (PTA) in children with cerebral palsy (CP). This study assesses changes in hamstring muscle tendon length (MTL) and velocity after DFEO (+PTA). Nineteen children (mean age 13y [standard deviation 3y] at surgery) with CP and flexed knee gait who were treated with DFEO (15 limbs) or DFEO+PTA (10 limbs) were retrospectively included in this study. Gait analyses were performed preoperatively (E0), 1 year postoperatively (E1), and for 10 limbs additionally 2 to 5 years postoperatively (E2). Hamstring MTL and velocities were assessed at all examination dates using OpenSim. Hamstring MTL and velocity did not change significantly over time. From E0 to E1, knee flexion in stance improved for both DFEO and DFEO+PTA (p<0.05), knee flexion in swing only improved after DFEO+PTA (p<0.05). The improved knee flexion in stance and swing was maintained at E2. DFEO led to a significant improvement in knee kinematics at E1 which was maintained at E2. DFEO seems to prevent recurrent hamstring tightness but does not lead to lengthened or fastened hamstrings. Distal femoral extension osteotomy (DFEO) does not change hamstring muscle tendon length. DFEO does not change hamstring lengthening velocity. DFEO leads to a significant improvement in knee kinematics. Changes in knee kinematics after DFEO can be maintained at mid-term. DFEO seems to prevent recurrent hamstring tightness. © 2018 Mac Keith Press.

Intra-operative digital imaging: assuring the alignment of components when undertaking total hip arthroplasty.

PubMed

Hambright, D; Hellman, M; Barrack, R

2018-01-01

The aims of this study were to examine the rate at which the positioning of the acetabular component, leg length discrepancy and femoral offset are outside an acceptable range in total hip arthroplasties (THAs) which either do or do not involve the use of intra-operative digital imaging. A retrospective case-control study was undertaken with 50 patients before and 50 patients after the integration of an intra-operative digital imaging system in THA. The demographics of the two groups were comparable for body mass index, age, laterality and the indication for surgery. The digital imaging group had more men than the group without. Surgical data and radiographic parameters, including the inclination and anteversion of the acetabular component, leg length discrepancy, and the difference in femoral offset compared with the contralateral hip were collected and compared, as well as the incidence of altering the position of a component based on the intra-operative image. Digital imaging took a mean of five minutes (2.3 to 14.6) to perform. Intra-operative changes with the use of digital imaging were made for 43 patients (86%), most commonly to adjust leg length and femoral offset. There was a decrease in the incidence of outliers when using intra-operative imaging compared with not using it in regard to leg length discrepancy (20% versus 52%, p = 0.001) and femoral offset inequality (18% versus 44%, p = 0.004). There was also a difference in the incidence of outliers in acetabular inclination (0% versus 7%, p = 0.023) and version (0% versus 4%, p = 0.114) compared with historical results of a high-volume surgeon at the same centre. The use of intra-operative digital imaging in THA improves the accuracy of the positioning of the components at THA without adding a substantial amount of time to the operation. Cite this article: Bone Joint J 2018;100B(1 Supple A):36-43. ©2018 The British Editorial Society of Bone & Joint Surgery.

Leg length, sitting height, and body proportions references for achondroplasia: New tools for monitoring growth.

PubMed

Del Pino, Mariana; Ramos Mejía, Rosario; Fano, Virginia

2018-04-01

Achondroplasia is the most common form of inherited disproportionate short stature. We report leg length, sitting height, and body proportion curves for achondroplasia. Seven centile format of sitting height, leg length, sitting height/leg length ratio, sitting height/height ratio, and head circumference/height ratio were estimated by the LMS method. The Q-test was applied to assess the goodness of fit. For comparison, centiles of sitting height and leg length were graphed using Argentine national growth references for achondroplasia and non-achondroplasia populations. The sample consisted of 342 children with achondroplasia (171 males, 171 females) aged 0-18 years. The median (interquartile range) number of measurements per child was 6 (3, 12) for sitting height and 8 (3, 13) for head circumference. Median leg length increased from 14 cm at age 1 week to 44 and 40 cm (males and females, respectively) in achondroplasia adolescents which is 3.5 cm shorter than non-achondroplasia children at age 1 week and, 38 cm shorter at adolescence. Median sitting height increased from 34 cm at birth to 86 and 81 in adolescents' boys and girls respectively, only 5 cm shorter than non-achondroplasia children. Sitting height/leg length decreased from 2.61 at birth to approximately 1.90 at adolescent. Median head circumference/height ratio decreased from 0.79 at birth to 0.46 at 18 years in both sexes. Growth of lower limbs is affected early in life and becomes more noticeable throughout childhood. The disharmonic growth between the less affected trunk and the severely affected limbs determine body disproportion in achondroplasia. © 2018 Wiley Periodicals, Inc.

Effects of Gait Training With Body Weight Support on a Treadmill Versus Overground in Individuals With Stroke.

PubMed

Gama, Gabriela L; Celestino, Melissa L; Barela, José A; Forrester, Larry; Whitall, Jill; Barela, Ana M

2017-04-01

To investigate the effects of gait training with body weight support (BWS) on a treadmill versus overground in individuals with chronic stroke. Randomized controlled trial. University research laboratory. Individuals (N=28) with chronic stroke (>6mo from the stroke event). Participants were randomly assigned to receive gait training with BWS on a treadmill (n=14) or overground (n=14) 3 times a week for 6 weeks. Gait speed measured using the 10-meter walk test, endurance measured using the 6-minute walk test, functional independence measured using the motor domain of the FIM, lower limb recovery measured using the lower extremity domain of the Fugl-Meyer assessment, step length, step length symmetry ratio, and single-limb support duration. Measurements were obtained at baseline, immediately after the training session, and 6 weeks after the training session. At 1 week after the last training session, both groups improved in all outcome measures except paretic step length and step length symmetry ratio, which were improved only in the overground group (P=.01 and P=.01, respectively). At 6 weeks after the last training session, all improvements remained and the treadmill group also improved paretic step length (P<.001) but not step length symmetry ratio (P>.05). Individuals with chronic stroke equally improve gait speed and other gait parameters after 18 sessions of BWS gait training on either a treadmill or overground. Only the overground group improved step length symmetry ratio, suggesting a role of integrating overground walking into BWS interventions poststroke. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Static innominate asymmetry and leg length discrepancy in asymptomatic collegiate athletes.

PubMed

Krawiec, C J; Denegar, C R; Hertel, J; Salvaterra, G F; Buckley, W E

2003-11-01

The objectives of the study were to assess: (1) static innominate asymmetry in the sagittal plane, (2) leg length discrepancy (LLD), and (3) the relationship between static innominate rotation and LLD in asymptomatic collegiate athletes. The study was an observational study by design which took place in a University athletic training research laboratory. The participants were twenty-four male and 20 female asymptomatic intercollegiate athletes who volunteered to take part in the study. Static innominate asymmetry was assessed with a caliper/inclinometer tool and LLD was measured with a tape measure using standard clinical methods. Results showed that forty-two subjects (95%) demonstrated some degree of static innominate asymmetry. In 32 subjects (73%), the right innominate was more anteriorly rotated than the left. Nearly all subjects were determined to have unequal leg lengths with a majority, 30 subjects (68%), showing a slightly longer left leg. Weak correlations (r=0.33 - 0.44) were identified between static innominate asymmetry and LLD. In Conclusion static innominate asymmetry and LLD are common among asymptomatic collegiate athletes. This information provides clinicians with normative data of common clinical measures in a physically active population.

Reconciling extreme branch length differences: decoupling time and rate through the evolutionary history of filmy ferns.

PubMed

Schuettpelz, Eric; Pryer, Kathleen M

2006-06-01

The rate of molecular evolution is not constant across the Tree of Life. Characterizing rate discrepancies and evaluating the relative roles of time and rate along branches through the past are both critical to a full understanding of evolutionary history. In this study, we explore the interactions of time and rate in filmy ferns (Hymenophyllaceae), a lineage with extreme branch length differences between the two major clades. We test for the presence of significant rate discrepancies within and between these clades, and we separate time and rate across the filmy fern phylogeny to simultaneously yield an evolutionary time scale of filmy fern diversification and reconstructions of ancestral rates of molecular evolution. Our results indicate that the branch length disparity observed between the major lineages of filmy ferns is indeed due to a significant difference in molecular evolutionary rate. The estimation of divergence times reveals that the timing of crown group diversification was not concurrent for the two lineages, and the reconstruction of ancestral rates of molecular evolution points to a substantial rate deceleration in one of the clades. Further analysis suggests that this may be due to a genome-wide deceleration in the rate of nucleotide substitution.

Anthropometric Study of the Piriformis Muscle and Sciatic Nerve: A Morphological Analysis in a Polish Population

PubMed Central

Haładaj, Robert; Pingot, Mariusz; Polguj, Michał; Wysiadecki, Grzegorz; Topol, Mirosław

2015-01-01

Background The aim of this study was to determine relationships between piriformis muscle (PM) and sciatic nerve (SN) with reference to sex and anatomical variations. Material/Methods Deep dissection of the gluteal region was performed on 30 randomized, formalin-fixed human lower limbs of adults of both sexes of the Polish population. Anthropometric measurements were taken and then statistically analyzed. Results The conducted research revealed that, apart from the typical structure of the piriformis muscle, the most common variation was division of the piriformis muscle into two heads, with the common peroneal nerve running between them (20%). The group with anatomical variations of the sciatic nerve course displayed greater diversity of morphometric measurement results. There was a statistically significant correlation between the lower limb length and the distance from the sciatic nerve to the greater trochanter in the male specimens. On the other hand, in the female specimens, a statistically significant correlation was observed between the lower limb length and the distance from the sciatic nerve to the ischial tuberosity. The shortest distance from the sciatic nerve to the greater trochanter measured at the level of the inferior edge of the piriformis was 21 mm, while the shortest distance to the ischial tuberosity was 63 mm. Such correlations should be taken into account during invasive medical procedures performed in the gluteal region. Conclusions It is possible to distinguish several anatomical variations of the sciatic nerve course within the deep gluteal region. The statistically significant correlations between some anthropometric measurements were only present within particular groups of male and female limbs. PMID:26629744

Independence and mobility after infrainguinal lower limb bypass surgery for critical limb ischemia.

PubMed

Ambler, Graeme K; Dapaah, Andrew; Al Zuhir, Naail; Hayes, Paul D; Gohel, Manjit S; Boyle, Jonathan R; Varty, Kevin; Coughlin, Patrick A

2014-04-01

Critical limb ischemia (CLI) is a common condition associated with high levels of morbidity and mortality. Most work to date has focused on surgeon-oriented outcomes such as patency, but there is increasing interest in patient-oriented outcomes such as mobility and independence. This study was conducted to determine the effect of infrainguinal lower limb bypass surgery (LLBS) on postoperative mobility in a United Kingdom tertiary vascular surgery unit and to investigate causes and consequences of poor postoperative mobility. We collected data on all patients undergoing LLBS for CLI at our institution during a 3-year period and analyzed potential factors that correlated with poor postoperative mobility. During the study period, 93 index LLBS procedures were performed for patients with CLI. Median length of stay was 11 days (interquartile range, 11 days). The 12-month rates of graft patency, major amputation, and mortality were 75%, 9%, and 6%, respectively. Rates of dependence increased fourfold during the first postoperative year, from 5% preoperatively to 21% at 12 months. Predictors of poor postoperative mobility were female sex (P = .04) and poor postoperative mobility (P < .001), initially and at the 12-month follow-up. Patients with poor postoperative mobility had significantly prolonged hospital length of stay (15 vs 8 days; P < .001). Patients undergoing LLBS for CLI suffer significantly impaired postoperative mobility, and this is associated with prolonged hospital stay, irrespective of successful revascularization. Further work is needed to better predict patients who will benefit from revascularization and in whom a nonoperative strategy is optimal. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Relationship between asymmetry of quiet standing balance control and walking post-stroke.

PubMed

Hendrickson, Janna; Patterson, Kara K; Inness, Elizabeth L; McIlroy, William E; Mansfield, Avril

2014-01-01

Spatial and temporal gait asymmetry is common after stroke. Such asymmetric gait is inefficient, can contribute to instability and may lead to musculoskeletal injury. However, understanding of the determinants of such gait asymmetry remains incomplete. The current study is focused on revealing if there is a link between asymmetry during the control of standing balance and asymmetry during walking. This study involved review of data from 94 individuals with stroke referred to a gait and balance clinic. Participants completed three tests: (1) walking at their usual pace; (2) quiet standing; and (3) standing with maximal loading of the paretic side. A pressure sensitive mat recorded placement and timing of each footfall during walking. Standing tests were completed on two force plates to evaluate symmetry of weight bearing and contribution of each limb to balance control. Multiple regression was conducted to determine the relationships between symmetry during standing and swing time, stance time, and step length symmetry during walking. Symmetry of antero-posterior balance control and weight bearing were related to swing time and step length symmetry during walking. Weight-bearing symmetry, weight-bearing capacity, and symmetry of antero-posterior balance control were related to stance time symmetry. These associations were independent of underlying lower limb impairment. The results support the hypothesis that impaired ability of the paretic limb to control balance may contribute to gait asymmetry post-stroke. Such work suggests that rehabilitation strategies that increase the contribution of the paretic limb to standing balance control may increase symmetry of walking post-stroke. Copyright © 2013 Elsevier B.V. All rights reserved.

A k-omega multivariate beta PDF for supersonic turbulent combustion

NASA Technical Reports Server (NTRS)

Alexopoulos, G. A.; Baurle, R. A.; Hassan, H. A.

1993-01-01

In a recent attempt by the authors at predicting measurements in coaxial supersonic turbulent reacting mixing layers involving H2 and air, a number of discrepancies involving the concentrations and their variances were noted. The turbulence model employed was a one-equation model based on the turbulent kinetic energy. This required the specification of a length scale. In an attempt at detecting the cause of the discrepancy, a coupled k-omega joint probability density function (PDF) is employed in conjunction with a Navier-Stokes solver. The results show that improvements resulting from a k-omega model are quite modest.

Morphology, body proportions, and postcranial hypertrophy of a female Neandertal from the Sima de las Palomas, southeastern Spain.

PubMed

Walker, Michael J; Ortega, Jon; Parmová, Klara; López, Mariano V; Trinkaus, Erik

2011-06-21

Considerations of Neandertal geographical variation have been hampered by the dearth of remains from Mediterranean Europe and the absence there of sufficiently complete associated postcrania. The 2006 and 2007 excavation of an articulated partial skeleton of a small adult female Neandertal at the Sima de las Palomas, Murcia, southeastern Spain (Sima de las Palomas 96) provides substantial and secure information on body proportions among southern European Neandertals, as well as further documenting the nature of Neandertal biology in southern Iberia. The remains exhibit a suite of cranial, mandibular, dental, and postcranial features, of both Neandertals and archaic Homo generally, that distinguish them from contemporary and subsequent early modern humans. Its lower limbs exhibit the robustness of later Pleistocene Homo generally, and its upper limbs conform to the pattern of elevated robustness of the Neandertals. Its body proportions, including relative clavicular length, distal limb segment lengths, and body mass to stature indicators, conform to the "cold-adapted" pattern of more northern Neandertals. Palomas 96 therefore documents the presence of a suite of "Neandertal" characteristics in southern Iberia and, along with its small body size, the more "Arctic" body proportions of other European Neandertals despite the warmer climate of southern Iberia during marine isotope stage 3.

A Novel Non-Invasive Selection Criterion for the Preservation of Primitive Dutch Konik Horses

PubMed Central

May-Davis, Sharon; Shorter, Kathleen; Vermeulen, Zefanja; Butler, Raquel; Koekkoek, Marianne

2018-01-01

The Dutch Konik is valued from a genetic conservation perspective and also for its role in preservation of natural landscapes. The primary management objective for the captive breeding of this primitive horse is to maintain its genetic purity, whilst also maintaining the nature reserves on which they graze. Breeding selection has traditionally been based on phenotypic characteristics consistent with the breed description, and the selection of animals for removal from the breeding program is problematic at times due to high uniformity within the breed, particularly in height at the wither, colour (mouse to grey dun) and presence of primitive markings. With the objective of identifying an additional non-invasive selection criterion with potential uniqueness to the Dutch Konik, this study investigates the anatomic parameters of the distal equine limb, with a specific focus on the relative lengths of the individual splint bones. Post-mortem dissections performed on distal limbs of Dutch Konik (n = 47) and modern domesticated horses (n = 120) revealed significant differences in relation to the length and symmetry of the 2nd and 4th Metacarpals and Metatarsals. Distal limb characteristics with apparent uniqueness to the Dutch Konik are described which could be an important tool in the selection and preservation of the breed. PMID:29389896

Association between Functional Severity and Amputation Type with Rehabilitation Outcomes in Patients with Lower Limb Amputation

PubMed Central

Graham, James E.; Reistetter, Timothy A.; Kumar, Amit; Niewczyk, Paulette; Granger, Carl V.; Ottenbacher, Kenneth J.

2014-01-01

The purpose of this study was to determine independent influences of functional level and lower limb amputation type on inpatient rehabilitation outcomes. We conducted a secondary data analysis for patients with lower limb amputation who received inpatient medical rehabilitation (N = 26,501). The study outcomes included length of stay, discharge functional status, and community discharge. Predictors included the 3-level case mix group variable and a 4-category amputation variable. Age of the sample was 64.5 years (13.4) and 64% were male. More than 75% of patients had a dysvascular-related amputation. Patients with bilateral transfemoral amputations and higher functional severity experienced longest lengths of stay (average 13.7 days) and lowest functional rating at discharge (average 79.4). Likelihood of community discharge was significantly lower for those in more functionally severe patients but did not differ between amputation categories. Functional levels and amputation type are associated with rehabilitation outcomes in inpatient rehabilitation settings. Patients with transfemoral amputations and those in case mix group 1003 (admission motor score less than 36.25) generally experience poorer outcomes than those in other case mix groups. These relationships may be associated with other demographic and/or health factors, which should be explored in future research. PMID:25400948

A Novel Non-Invasive Selection Criterion for the Preservation of Primitive Dutch Konik Horses.

PubMed

May-Davis, Sharon; Brown, Wendy Y; Shorter, Kathleen; Vermeulen, Zefanja; Butler, Raquel; Koekkoek, Marianne

2018-02-01

The Dutch Konik is valued from a genetic conservation perspective and also for its role in preservation of natural landscapes. The primary management objective for the captive breeding of this primitive horse is to maintain its genetic purity, whilst also maintaining the nature reserves on which they graze. Breeding selection has traditionally been based on phenotypic characteristics consistent with the breed description, and the selection of animals for removal from the breeding program is problematic at times due to high uniformity within the breed, particularly in height at the wither, colour (mouse to grey dun) and presence of primitive markings. With the objective of identifying an additional non-invasive selection criterion with potential uniqueness to the Dutch Konik, this study investigates the anatomic parameters of the distal equine limb, with a specific focus on the relative lengths of the individual splint bones. Post-mortem dissections performed on distal limbs of Dutch Konik ( n = 47) and modern domesticated horses ( n = 120) revealed significant differences in relation to the length and symmetry of the 2nd and 4th Metacarpals and Metatarsals. Distal limb characteristics with apparent uniqueness to the Dutch Konik are described which could be an important tool in the selection and preservation of the breed.

Defining the local nerve blocks for feline distal thoracic limb surgery: a cadaveric study

PubMed Central

Enomoto, Masataka; Lascelles, B Duncan X; Gerard, Mathew P

2016-01-01

Objectives Though controversial, onychectomy remains a commonly performed distal thoracic limb surgical procedure in cats. Peripheral nerve block techniques have been proposed in cats undergoing onychectomy but evidence of efficacy is lacking. Preliminary tests of the described technique using cadavers resulted in incomplete staining of nerves. The aim of this study was to develop nerve block methods based on cadaveric dissections and test these methods with cadaveric dye injections. Methods Ten pairs of feline thoracic limbs (n = 20) were dissected and superficial branches of the radial nerve (RSbr nn.), median nerve (M n.), dorsal branch of ulnar nerve (UDbr n.), superficial branch of palmar branch of ulnar nerve (UPbrS n.) and deep branch of palmar branch of ulnar nerve (UPbrDp n.) were identified. Based on these dissections, a four-point block was developed and tested using dye injections in another six pairs of feline thoracic limbs (n = 12). Using a 25 G × 5/8 inch needle and 1 ml syringe, 0.07 ml/kg methylene blue was injected at the site of the RSbr nn., 0.04 ml/kg at the injection site of the UDbr n., 0.08 ml/kg at the injection site of the M n. and UPbrS n., and 0.01 ml/kg at the injection site of the UPbrDp n. The length and circumference of each nerve that was stained was measured. Results Positive staining of all nerves was observed in 12/12 limbs. The lengths stained for RSbr nn., M n., UDbr n., UPbrS n. and UPbrDp n. were 34.9 ± 5.3, 26.4 ± 4.8, 29.2 ± 4.0, 39.1 ± 4.3 and 17.5 ± 3.3 mm, respectively. The nerve circumferences stained were 93.8 ± 15.5, 95.8 ± 9.7, 100 ± 0.0, 100 ± 0.0 and 93.8 ± 15.5%, respectively. Conclusions and relevance This described four-point injection method may be an effective perioperative analgesia technique for feline distal thoracic limb procedures. PMID:26250858

Measuring upper limb function in children with hemiparesis with 3D inertial sensors.

PubMed

Newman, Christopher J; Bruchez, Roselyn; Roches, Sylvie; Jequier Gygax, Marine; Duc, Cyntia; Dadashi, Farzin; Massé, Fabien; Aminian, Kamiar

2017-12-01

Upper limb assessments in children with hemiparesis rely on clinical measurements, which despite standardization are prone to error. Recently, 3D movement analysis using optoelectronic setups has been used to measure upper limb movement, but generalization is hindered by time and cost. Body worn inertial sensors may provide a simple, cost-effective alternative. We instrumented a subset of 30 participants in a mirror therapy clinical trial at baseline, post-treatment, and follow-up clinical assessments, with wireless inertial sensors positioned on the arms and trunk to monitor motion during reaching tasks. Inertial sensor measurements distinguished paretic and non-paretic limbs with significant differences (P < 0.01) in movement duration, power, range of angular velocity, elevation, and smoothness (normalized jerk index and spectral arc length). Inertial sensor measurements correlated with functional clinical tests (Melbourne Assessment 2); movement duration and complexity (Higuchi fractal dimension) showed moderate to strong negative correlations with clinical measures of amplitude, accuracy, and fluency. Inertial sensor measurements reliably identify paresis and correlate with clinical measurements; they can therefore provide a complementary dimension of assessment in clinical practice and during clinical trials aimed at improving upper limb function.

Changes in expression of the lysosomal membrane glycoprotein, LAMP-1 in interdigital regions during embryonic mouse limb development, in vivo and in vitro.

PubMed

Stewart, S; Yi, S; Kassabian, G; Mayo, M; Sank, A; Shuler, C

2000-06-01

Syndactyly, a failure of the digits to separate into individual units, affects about 8 to 9 per 1000 newborns and results from an aberration of the normal development of the interdigital tissues. Limb digit separation is the result of programmed cell death (apoptosis). Lysosomes play a role in the process of cell self-destruction. Our experiment was designed to test the hypothesis that the intensity of interdigital lysosomes increases during the separation of digits in vivo and in vitro. The primary mouse monoclonal antibody, 1D4B, detects the presence of lysosomes by identifying the LAMP-1 glycoprotein on the lysosome cell membrane. In our experiment this antibody immunodetected interdigital lysosome proteins in serial sections of limbs from Swiss-Webster mouse embryos, gestational ages E12.5 through E15, key developmental stages for digit separation. Digit separation was associated with an increase in intensity of lysosomal protein staining. In E12.5 limbs, the presence of lysosomes was enriched in the distal aspect of the interdigital tissue. However, the number of lysosomes markedly increased in the E13 and E14 limbs, including the entire length and width of the interdigital tissue in the E14 limbs. This lysosomal protein presence in E14 limbs was significant compared to E12.5, E13, and E15 limbs. By day 12.5, the mouse embryo limb is committed to digit separation. Addition of retinoic acid to the culture medium of limbs earlier in development, such as E12, results in induction of the process of digit separation. Cultured E12 limbs that did not receive an addition of retinoic acid, did not show digit separation. We conclude that in the limb development process, the enrichment in interdigit LAMP-1 proteins, may indicate a relationship between lysosomes, apoptosis, and digit separation. We also conclude that retinoic acid has an important role in digit separation in vivo, as shown in limb development, and demonstrated through the addition of retinoic acid to media of cultured tissues.

Report: Congressionally Requested Information on the Status and Length of Review for Appalachian Surface Mining Permit Applications

EPA Pesticide Factsheets

Report #12-P-0083, November 21, 2011. After reconciling discrepancies and vetting information, we identified 185 surface mining permit applications to review from the list of 237 that we received from the senator.

Function of a large biarticular hip and knee extensor during walking and running in guinea fowl (Numida meleagris).

PubMed

Carr, Jennifer A; Ellerby, David J; Marsh, Richard L

2011-10-15

Physiological and anatomical evidence suggests that in birds the iliotibialis lateralis pars postacetabularis (ILPO) is functionally important for running. Incorporating regional information, we estimated the mean sarcomere strain trajectory and electromyographic (EMG) amplitude of the ILPO during level and incline walking and running. Using these data and data in the literature of muscle energy use, we examined three hypotheses: (1) active lengthening will occur on the ascending limb of the length-tension curve to avoid potential damage caused by stretch on the descending limb; (2) the active strain cycle will shift to favor active shortening when the birds run uphill and shortening will occur on the plateau and shallow ascending limb of the length-tension curve; and (3) measures of EMG intensity will correlate with energy use when the mechanical function of the muscle is similar. Supporting the first hypothesis, we found that the mean sarcomere lengths at the end of active lengthening during level locomotion were smaller than the predicted length at the start of the plateau of the length-tension curve. Supporting the second hypothesis, the magnitude of active lengthening decreased with increasing slope, whereas active shortening increased. In evaluating the relationship between EMG amplitude and energy use (hypothesis 3), we found that although increases in EMG intensity with speed, slope and loading were positively correlated with muscle energy use, the quantitative relationships between these variables differed greatly under different conditions. The relative changes in EMG intensity and energy use by the muscle probably varied because of changes in the mechanical function of the muscle that altered the ratio of muscle energy use to active muscle volume. Considering the overall function of the cycle of active lengthening and shortening of the fascicles of the ILPO, we conclude that the function of active lengthening is unlikely to be energy conservation and may instead be related to promoting stability at the knee. The work required to lengthen the ILPO during stance is provided by co-contracting knee flexors. We suggest that this potentially energetically expensive co-contraction serves to stabilize the knee in early stance by increasing the mechanical impedance of the joint.

Can we predict body height from segmental bone length measurements? A study of 3,647 children.

PubMed

Cheng, J C; Leung, S S; Chiu, B S; Tse, P W; Lee, C W; Chan, A K; Xia, G; Leung, A K; Xu, Y Y

1998-01-01

It is well known that significant differences exist in the anthropometric data of different races and ethnic groups. This is a cross-sectional study on segmental bone length based on 3,647 Chinese children of equal sex distribution aged 3-18 years. The measurements included standing height, weight, arm span, foot length, and segmental bone length of the humerus, radius, ulna, and tibia. A normality growth chart of all the measured parameters was constructed. Statistical analysis of the results showed a very high linear correlation of height with arm span, foot length, and segmental bone lengths with a correlation coefficient of 0.96-0.99 for both sexes. No differences were found between the right and left side of all the segmental bone lengths. These Chinese children were found to have a proportional limb segmental length relative to the trunk.

The assessment of postural control and the influence of a secondary task in people with anterior cruciate ligament reconstructed knees using a Nintendo Wii Balance Board.

PubMed

Howells, Brooke E; Clark, Ross A; Ardern, Clare L; Bryant, Adam L; Feller, Julian A; Whitehead, Timothy S; Webster, Kate E

2013-09-01

Postural control impairments may persist following anterior cruciate ligament (ACL) reconstruction. The effect of a secondary task on postural control has, however, not been determined. The purpose of this case-control study was to compare postural control in patients following ACL reconstruction with healthy individuals with and without a secondary task. 45 patients (30 men and 15 women) participated at least 6 months following primary ACL reconstruction surgery. Participants were individually matched by age, gender and sports activity to healthy controls. Postural control was measured using a Nintendo Wii Balance Board and customised software during static single-leg stance and with the addition of a secondary task. The secondary task required participants to match the movement of an oscillating marker by adducting and abducting their arm. Centre of pressure (CoP) path length in both medial-lateral and anterior-posterior directions, and CoP total path length. When compared with the control group, the anterior-posterior path length significantly increased in the ACL reconstruction patients' operated (12.3%, p=0.02) and non-operated limbs (12.8%, p=0.02) for the single-task condition, and the non-operated limb (11.5%, p=0.006) for the secondary task condition. The addition of a secondary task significantly increased CoP path lengths in all measures (p<0.001), although the magnitude of the increase was similar in both the ACL reconstruction and control groups. ACL reconstruction patients showed a reduced ability in both limbs to control the movement of the body in the anterior-posterior direction. The secondary task affected postural control by comparable amounts in patients after ACL reconstruction and healthy controls. Devices for the objective measurement of postural control, such as the one used in this study, may help clinicians to more accurately identify patients with deficits who may benefit from targeted neuromuscular training programs.

Architecture of kangaroo rat inner medulla: segmentation of descending thin limb of Henle's loop.

PubMed

Urity, Vinoo B; Issaian, Tadeh; Braun, Eldon J; Dantzler, William H; Pannabecker, Thomas L

2012-03-15

We hypothesize that the inner medulla of the kangaroo rat Dipodomys merriami, a desert rodent that concentrates its urine to more than 6,000 mosmol/kgH(2)O water, provides unique examples of architectural features necessary for production of highly concentrated urine. To investigate this architecture, inner medullary nephron segments in the initial 3,000 μm below the outer medulla were assessed with digital reconstructions from physical tissue sections. Descending thin limbs of Henle (DTLs), ascending thin limbs of Henle (ATLs), and collecting ducts (CDs) were identified by immunofluorescence using antibodies that label segment-specific proteins associated with transepithelial water flux (aquaporin 1 and 2, AQP1 and AQP2) and chloride flux (the chloride channel ClC-K1); all tubules and vessels were labeled with wheat germ agglutinin. In the outer 3,000 μm of the inner medulla, AQP1-positive DTLs lie at the periphery of groups of CDs. ATLs lie inside and outside the groups of CDs. Immunohistochemistry and reconstructions of loops that form their bends in the outer 3,000 μm of the inner medulla show that, relative to loop length, the AQP1-positive segment of the kangaroo rat is significantly longer than that of the Munich-Wistar rat. The length of ClC-K1 expression in the prebend region at the terminal end of the descending side of the loop in kangaroo rat is about 50% shorter than that of the Munich-Wistar rat. Tubular fluid of the kangaroo rat DTL may approach osmotic equilibrium with interstitial fluid by water reabsorption along a relatively longer tubule length, compared with Munich-Wistar rat. A relatively shorter-length prebend segment may promote a steeper reabsorptive driving force at the loop bend. These structural features predict functionality that is potentially significant in the production of a high urine osmolality in the kangaroo rat.

The healing process of intracorporeally and in situ devitalized distal femur by microwave in a dog model and its mechanical properties in vitro.

PubMed

Ji, Zhenwei; Ma, Yunlei; Li, Wei; Li, Xiaoxiang; Zhao, Guangyi; Yun, Zhe; Qian, Jixian; Fan, Qingyu

2012-01-01

Limb-salvage surgery has been well recognized as a standard treatment and alternative to amputation for patients with malignant bone tumors. Various limb-sparing techniques have been developed including tumor prosthesis, allograft, autograft and graft-prosthesis composite. However, each of these methods has short- and long-term disadvantages such as nonunion, mechanical failures and poor limb function. The technique of intracorporeal devitalization of tumor-bearing bone segment in situ by microwave-induced hyperthermia after separating it from surrounding normal tissues with a safe margin is a promising limb-salvage method, which may avoid some shortcomings encountered by the above-mentioned conventional techniques. The purpose of this study is to assess the healing process and revitalization potential of the devitalized bone segment by this method in a dog model. In addition, the immediate effect of microwave on the biomechanical properties of bone tissue was also explored in an in vitro experiment. We applied the microwave-induced hyperthermia to devitalize the distal femurs of dogs in situ. Using a monopole microwave antenna, we could produce a necrotic bone of nearly 20 mm in length in distal femur. Radiography, bone scintigraphy, microangiography, histology and functional evaluation were performed at 2 weeks and 1, 2, 3, 6, 9 and 12 months postoperatively to assess the healing process. In a biomechanical study, two kinds of bone specimens, 3 and 6 cm in length, were used for compression and three-point bending test respectively immediately after extracorporeally devitalized by microwave. An in vivo study showed that intracorporeally and in situ devitalized bone segment by microwave had great revitalization potential. An in vitro study revealed that the initial mechanical strength of the extracorporeally devitalized bone specimen may not be affected by microwave. Our results suggest that the intracorporeal microwave devitalization of tumor-bearing bone segment in situ may be a promising limb-salvage method.

Kinematic Adaptations of Forward And Backward Walking on Land and in Water

PubMed Central

Cadenas-Sanchez, Cristina; Arellano, Raúl; Vanrenterghem, Jos; López-Contreras, Gracia

2015-01-01

The aim of this study was to compare sagittal plane lower limb kinematics during walking on land and submerged to the hip in water. Eight healthy adults (age 22.1 ± 1.1 years, body height 174.8 ± 7.1 cm, body mass 63.4 ± 6.2 kg) were asked to cover a distance of 10 m at comfortable speed with controlled step frequency, walking forward or backward. Sagittal plane lower limb kinematics were obtained from three dimensional video analysis to compare spatiotemporal gait parameters and joint angles at selected events using two-way repeated measures ANOVA. Key findings were a reduced walking speed, stride length, step length and a support phase in water, and step length asymmetry was higher compared to the land condition (p<0.05). At initial contact, knees and hips were more flexed during walking forward in water, whilst, ankles were more dorsiflexed during walking backward in water. At final stance, knees and ankles were more flexed during forward walking, whilst the hip was more flexed during backward walking. These results show how walking in water differs from walking on land, and provide valuable insights into the development and prescription of rehabilitation and training programs. PMID:26839602

The expression of the skeletal muscle force-length relationship in vivo: a simulation study.

PubMed

Winter, Samantha L; Challis, John H

2010-02-21

The force-length relationship is one of the most important mechanical characteristics of skeletal muscle in humans and animals. For a physiologically realistic joint range of motion and therefore range of muscle fibre lengths only part of the force-length curve may be used in vivo, i.e. only a section of the force-length curve is expressed. A generalised model of a mono-articular muscle-tendon complex was used to examine the effect of various muscle architecture parameters on the expressed section of the force-length relationship for a 90 degrees joint range of motion. The parameters investigated were: the ratio of tendon resting length to muscle fibre optimum length (L(TR):L(F.OPT)) (varied from 0.5 to 11.5), the ratio of muscle fibre optimum length to average moment arm (L(F.OPT):r) (varied from 0.5 to 5), the normalised tendon strain at maximum isometric force (c) (varied from 0 to 0.08), the muscle fibre pennation angle (theta) (varied from 0 degrees to 45 degrees) and the joint angle at which the optimum muscle fibre length occurred (phi). The range of values chosen for each parameter was based on values reported in the literature for five human mono-articular muscles with different functional roles. The ratios L(TR):L(F.OPT) and L(F.OPT):r were important in determining the amount of variability in the expressed section of the force-length relationship. The modelled muscle operated over only one limb at intermediate values of these two ratios (L(TR):L(F.OPT)=5; L(F.OPT):r=3), whether this was the ascending or descending limb was determined by the precise values of the other parameters. It was concluded that inter-individual variability in the expressed section of the force-length relationship is possible, particularly for muscles with intermediate values of L(TR):L(F.OPT) and L(F.OPT):r such as the brachialis and vastus lateralis. Understanding the potential for inter-individual variability in the expressed section is important when using muscle models to simulate movement. (c) 2009 Elsevier Ltd. All rights reserved.

Intramedullary nailing: experience in 427 patients.

PubMed

Lambiris, E; Tyllianakis, M; Megas, P; Panagiotopoulos, E

1996-01-01

In the Orthopaedic Department in Patras University 427 intramedullary nailings in the lower limbs were performed between 1989 and 1994 and retrospectively reviewed to evaluate the range of complications. One hundred and seventy-two were nailings of the femur; 80 gamma nails mainly for subtrochanteric and intertrochanteric with subtrochanteric extension fractures were included, (total 252/59%); 175 (41%) were nailings of the tibia. Union was achieved in all case. Overall the complication rate in this series was 3.3% (14 cases) and included infection (4 cases), neuropraxia (2 cases), implant failure (5 cases), limb length deficiency (2 cases) and malrotation (1 case).

Intensity of emission lines of the quiescent solar corona: comparison between calculated and observed values

NASA Astrophysics Data System (ADS)

Krissinel, Boris

2018-03-01

The paper reports the results of calculations of the center-to-limb intensity of optically thin line emission in EUV and FUV wavelength ranges. The calculations employ a multicomponent model for the quiescent solar corona. The model includes a collection of loops of various sizes, spicules, and free (inter-loop) matter. Theoretical intensity values are found from probabilities of encountering parts of loops in the line of sight with respect to the probability of absence of other coronal components. The model uses 12 loops with sizes from 3200 to 210000 km with different values of rarefaction index and pressure at the loop base and apex. The temperature at loop apices is 1 400 000 K. The calculations utilize the CHIANTI database. The comparison between theoretical and observed emission intensity values for coronal and transition region lines obtained by the SUMER, CDS, and EIS telescopes shows quite satisfactory agreement between them, particularly for the solar disk center. For the data acquired above the limb, the enhanced discrepancies after the analysis refer to errors in EIS measurements.

Transcriptomic analysis of Portunus trituberculatus reveals a critical role for WNT4 and WNT signalling in limb regeneration.

PubMed

Liu, Lei; Fu, Yuanyuan; Zhu, Fang; Mu, Changkao; Li, Ronghua; Song, Weiwei; Shi, Ce; Ye, Yangfang; Wang, Chunlin

2018-06-05

The swimming crab (Portunus trituberculatus) is among the most economically important seawater crustacean species in Asia. Despite its commercial importance and being well-studied status, genomic and transcriptomic data are scarce for this crab species. In the present study, limb bud tissue was collected at different developmental stages post amputation for transcriptomic analysis. Illumina RNA-sequencing was applied to characterise the limb regeneration transcriptome and identify the most characteristic genes. A total of 289,018 transcripts were obtained by clustering and assembly of clean reads, producing 150,869 unigenes with an average length of 956 bp. Subsequent analysis revealed WNT signalling as the key pathway involved in limb regeneration, with WNT4 a key mediator. Overall, limb regeneration appears to be regulated by multiple signalling pathways, with numerous cell differentiation, muscle growth, moult, metabolism, and immune-related genes upregulated, including WNT4, LAMA, FIP2, FSTL5, TNC, HUS1, SWI5, NCGL, SLC22, PLA2, Tdc2, SMOX, GDH, and SMPD4. This is the first experimental study done on regenerating claws of P. trituberculatus. These findings expand existing sequence resources for crab species, and will likely accelerate research into regeneration and development in crustaceans, particularly functional studies on genes involved in limb regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

Limb Preservation With Isolated Limb Infusion for Locally Advanced Nonmelanoma Cutaneous and Soft-Tissue Malignant Neoplasms

PubMed Central

Turaga, Kiran K.; Beasley, Georgia M.; Kane, John M.; Delman, Keith A.; Grobmyer, Stephen R.; Gonzalez, Ricardo J.; Letson, G. Douglas; Cheong, David; Tyler, Douglas S.; Zager, Jonathan S.

2015-01-01

Objective To demonstrate the efficacy of isolated limb infusion (ILI) in limb preservation for patients with locally advanced soft-tissue sarcomas and nonmelanoma cutaneous malignant neoplasms. Background Locally advanced nonmelanoma cutaneous and soft-tissue malignant neoplasms, including soft-tissue sarcomas of the extremities, can pose significant treatment challenges. We report our experience, including responses and limb preservation rates, using ILI in cutaneous and soft-tissue malignant neoplasms. Methods We identified 22 patients with cutaneous and soft-tissue malignant neoplasms who underwent 26 ILIs with melphalan and actinomycin from January 1, 2004, through December 31, 2009, from 5 institutions. Outcome measures included limb preservation and in-field response rates. Toxicity was measured using the Wieberdink scale and serum creatinine phosphokinase levels. Results The median age was 70 years (range, 19-92 years), and 12 patients (55%) were women. Fourteen patients (64%) had sarcomas, 7 (32%) had Merkel cell carcinoma, and 1 (5%) had squamous cell carcinoma. The median length of stay was 5.5 days (interquartile range, 4-8 days). Twenty-five of the 26 ILIs (96%) resulted in Wieberdink grade III or less toxicity, and 1 patient (4%) developed grade IV toxicity. The median serum creatinine phosphokinase level was 127 U/L for upper extremity ILIs and 93 U/L for lower extremity ILIs. Nineteen of 22 patients (86%) underwent successful limb preservation. The 3-month in-field response rate was 79% (21% complete and 58% partial), and the median follow-up was 8.6 months (range, 1-63 months). Five patients underwent resection of disease after an ILI, of whom 80% are disease free at a median of 8.6 months. Conclusions Isolated limb infusion provides an attractive alternative therapy for regional disease control and limb preservation in patients with limb-threatening cutaneous and soft-tissue malignant neoplasms. Short-term response rates appear encouraging, yet durability of response is unknown. PMID:21768436

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishizuka, N.; Nakamura, T.; Kawate, T.

The Solar Optical Telescope on board Hinode has revealed numerous tiny jets in all regions of the chromosphere outside of sunspots. A typical chromospheric anemone jet has a cusp-shaped structure and bright footpoint, similar to the shape of an X-ray anemone jet observed previously with the Soft X-ray Telescope on board Yohkoh. The similarity in the shapes of chromospheric and X-ray anemone jets suggests that chromospheric anemone jets are produced as a result of the magnetic reconnection between a small bipole (perhaps a tiny emerging flux) and a pre-existing uniform magnetic field in the lower chromosphere. We examine various chromosphericmore » anemone jets in the solar active region near the solar limb and study the typical features (e.g., length, width, lifetime, and velocity) of the chromospheric anemone jets. Statistical studies show that chromospheric anemone jets have: (1) a typical length {approx}1.0-4.0 Mm, (2) a width {approx}100-400 km, (3) a lifetime {approx}100-500 s, and (4) a velocity {approx}5-20 km s{sup -1}. The velocity of the chromospheric anemone jets is comparable to the local Alfven speed in the lower solar chromosphere ({approx}10 km s{sup -1}). The histograms of chromospheric anemone jets near the limb and near the disk center show similar averages and shapes of distributions, suggesting that the characteristic behavior of chromospheric anemone jets is independent of whether they are observed on the disk or at the limb. The observed relationship between the velocity and length of chromospheric anemone jets shows that the jets do not follow ballistic motion but are more likely accelerated by some other mechanism. This is consistent with numerical simulations of chromospheric anemone jets.« less

Should Roux-en-Y gastric bypass biliopancreatic limb length be tailored to achieve improved diabetes outcomes?

PubMed

Nora, Mário; Morais, Tiago; Almeida, Rui; Guimarães, Marta; Monteiro, Mariana P

2017-12-01

The objective is to access the role of Roux-en-Y gastric bypass (RYGB) biliopancreatic limb (BPL) length in type 2 diabetes (T2D) outcomes.RYGB is more effective than medical intervention for T2D treatment in obese patients. Despite the scarcity of available data, previous reports suggest that modifications of the RYGB limb lengths could improve the antidiabetic effects of the surgery.A cohort of obese T2D patients (n = 114) were submitted to laparoscopic RYGB, either with a standard BPL (SBPL) (n = 41; BPL 84 ± 2 cm) or long BPL (LBPL) (n = 73; BPL = 200 cm) and routinely monitored for weight loss and diabetic status up to 5 years after surgery.Baseline clinical features in the 2 patient subgroups were similar. After surgery, there was a significant reduction of body mass index (BMI) in both the groups, although the percentage of excess BMI loss (%EBMIL) after 5 years was higher for LBPL (75.50 ± 2.63 LBPL vs 65.90 ± 3.61 SBPL, P = .04). T2D remission rate was also higher (73% vs 55%, P < .05), while disease relapse rate (13.0% vs 32.5%; P < .05) and antidiabetic drug requirement in patients with persistent diabetes were lower after LBPL. Preoperative T2D duration predicted disease remission, but only for SBPL.RYGB with a longer BPL improves %EBMIL, T2D remission, and glycemic control in those with persistent disease, while it decreases diabetes relapse rate over time. The antidiabetic effects of LBPL RYGB also are less influenced by the preoperative disease duration. These data suggest the RYGB procedure could be tailored to improve T2D outcomes.

Predicting Recovery Potential for Individual Stroke Patients Increases Rehabilitation Efficiency.

PubMed

Stinear, Cathy M; Byblow, Winston D; Ackerley, Suzanne J; Barber, P Alan; Smith, Marie-Claire

2017-04-01

Several clinical measures and biomarkers are associated with motor recovery after stroke, but none are used to guide rehabilitation for individual patients. The objective of this study was to evaluate the implementation of upper limb predictions in stroke rehabilitation, by combining clinical measures and biomarkers using the Predict Recovery Potential (PREP) algorithm. Predictions were provided for patients in the implementation group (n=110) and withheld from the comparison group (n=82). Predictions guided rehabilitation therapy focus for patients in the implementation group. The effects of predictive information on clinical practice (length of stay, therapist confidence, therapy content, and dose) were evaluated. Clinical outcomes (upper limb function, impairment and use, independence, and quality of life) were measured 3 and 6 months poststroke. The primary clinical practice outcome was inpatient length of stay. The primary clinical outcome was Action Research Arm Test score 3 months poststroke. Length of stay was 1 week shorter for the implementation group (11 days; 95% confidence interval, 9-13 days) than the comparison group (17 days; 95% confidence interval, 14-21 days; P =0.001), controlling for upper limb impairment, age, sex, and comorbidities. Therapists were more confident ( P =0.004) and modified therapy content according to predictions for the implementation group ( P <0.05). The algorithm correctly predicted the primary clinical outcome for 80% of patients in both groups. There were no adverse effects of algorithm implementation on patient outcomes at 3 or 6 months poststroke. PREP algorithm predictions modify therapy content and increase rehabilitation efficiency after stroke without compromising clinical outcome. URL: http://anzctr.org.au. Unique identifier: ACTRN12611000755932. © 2017 American Heart Association, Inc.

A Surgical Model of Posttraumatic Osteoarthritis With Histological and Gait Validation.

PubMed

Zahoor, Talal; Mitchell, Reed; Bhasin, Priya; Schon, Lew; Zhang, Zijun

2016-07-01

Posttraumatic osteoarthritis (PTOA) is secondary to an array of joint injuries. Animal models are useful tools for addressing the uniqueness of PTOA progression in each type of joint injury and developing strategies for PTOA prevention and treatment. Intra-articular fracture induces PTOA pathology. Descriptive laboratory study. Through a parapatellar incision, the medial tibial plateau was exposed in the left knees of 8 Sprague-Dawley rats. Osteotomy at the midpoint between the tibial crest and the outermost portion of the medial tibial plateau, including the covering articular cartilage, was performed using a surgical blade. The fractured medial tibial plateau was fixed with 2 needles transversely. The fractured knees were not immobilized. Before and after surgery, rat gait was recorded. Rats were sacrificed at week 8, and their knees were harvested for histology. After intra-articular fracture, the affected limbs altered gait from baseline (week 0). In the first 2 weeks, the gait of the operated limbs featured a reduced paw print intensity and stride length but increased maximal contact and stance time. Reduction of maximal and mean print area and duty cycle (the percentage of stance phase in a step) was present from week 1 to week 5. Only print length was reduced in weeks 7 and 8. At week 8, histology of the operated knees demonstrated osteoarthritic pathology. The severity of the PTOA pathology did not correlate with the changes of print length at week 8. Intra-articular fracture of the medial tibial plateau effectively induced PTOA in rat knees. During PTOA development, the injured limbs demonstrated characteristic gait. Intra-articular fracture represents severe joint injury and associates with a high rate of PTOA. This animal model, with histologic and gait validations, can be useful for future studies of PTOA prevention and early diagnosis.

Transfer of ipsilateral fibula on vascular pedicle for treatment of congenital pseudarthrosis of the tibia.

PubMed

Tan, Jane S; Roach, James W; Wang, Angela A

2011-01-01

Although the use of free vascularized fibula grafts has frequently been reported in the treatment of congenital pseudarthrosis of the tibia, the use of ipsilateral fibula graft on a vascular pedicle is uncommon. We reviewed the long-term results of this procedure in 11 patients. The records of 11 patients who underwent transfer of the ipsilateral fibula on a vascular pedicle between 2.1 and 10.8 years of age were retrospectively reviewed. Average follow-up was 11 years after the index procedure. Seven patients had reached skeletal maturity. Clinical records and radiographs were reviewed to determine patient demographics, surgical parameters, union rate, refracture rate, residual deformity, and functional outcome. Eight patients (73%) achieved union at an average of 20.1 months. Additional bone grafting procedures were required in 4 patients with distal nonunions. There were 3 refractures (38%). Four patients eventually underwent amputation, and 1 patient had a persistent nonunion at final follow-up. Residual deformity included tibial valgus and procurvatum deformities, limb length discrepancy, and ankle valgus. Use of the ipsilateral fibula did not seem to increase the risk of ankle valgus. Functional outcomes were good in all but one patient. Use of the ipsilateral fibula as a pedicle graft provides reasonable results in healing congenital pseudarthrosis of the tibia. Patients should be monitored for the sequelae of this condition, including nonunion, refracture, shortening, and angular deformity, and treated accordingly. Therapeutic Level IV.

Scheuermann's disease in a juvenile male from the late Roman necropolis of Torrenueva (3rd-4th century CE, Granada, Spain).

PubMed

Viciano, Joan; López-Lázaro, Sandra; Pérez-Fernández, Ángela; Amores-Ampuero, Anabel; D'Anastasio, Ruggero; Jiménez-Triguero, José Miguel

2017-09-01

This study details a severe case of Scheuermann's disease (SD) in a well-preserved skeleton of a juvenile male (designated TOR302), dated to 3rd-4th century CE, from the late Roman necropolis of Torrenueva (Granada, Spain). Individual TOR302 shows an evident kyphotic curve in the thoraco-lumbar spine, which is characterised by: (i) vertebral bodies of thoracic vertebra T2, thoracic segment T4-T9, and thoraco-lumbar segment T12-L2 wedged at >5°; (ii) slight anterior extensions of the epiphyseal ring; (iii) Schmorl's nodes on the superior and/or inferior plates; and (iv) a Cobb angle of 75°, derived from thoracic segments T4-T9. In addition, TOR302 shows other skeletal malformations as the secondary results of abnormal growth, due to altered biomechanical forces imposed by the spinal deformity, including: (i) lateral distortion of the spine that causes a slight secondary scoliotic curve; (ii) pelvic obliquity; and (iii) discrepancy in the length of the limbs. We argue that the secondary skeletal abnormalities allowed the individual to adapt to his spinal deformity meaning he was able to walk without the aid of a stick. Despite SD being a common modern clinical finding, few cases have been reported in ancient skeletal remains. This case therefore represents an important contribution to the palaeopathological literature. Copyright © 2017 Elsevier Inc. All rights reserved.

Tibial avulsion fracture of the posterior root of the medial meniscus in a skeletally-immature child - a case report.

PubMed

Matava, Matthew J; Kim, Young-Mo

2011-01-01

It has been theorized that a traumatic tibial avulsion fracture of the posterior root of the medial meniscus (MM) is the cause of the so-called meniscus ossicle (MO). We report the delayed appearance of a tibial avulsion fracture of the posterior root of the MM after a valgus, twisting injury in a 12-year-old boy with open physes. Magnetic resonance imaging (MRI) scans performed 3 days after the injury did not demonstrate a definitive tibial avulsion fracture of the posterior root of the MM; whereas, a repeat MRI for 3 months post-injury did. Medial extrusion of the MM was also noted on the 3 month MRI. Arthroscopic reattachment of the avulsed posterior root of the MM using a trans-physeal nonabsorbable suture tied over a proximal tibia staple was performed. Follow-up MRI at 6 months postoperatively demonstrated healing of the tibial avulsion fracture of the posterior root of the MM in an anatomic position. The patient had a complete resolution of symptoms and there was no angular deformity or limb-length discrepancy at 2 years postoperatively. To our knowledge, this is the first report describing a tibial avulsion fracture of the posterior root of the MM in a skeletally-immature patient successfully treated by a trans-physeal arthroscopic suture. This case also illustrates the development of the MO of the posterior root of the MM. Copyright © 2010 Elsevier B.V. All rights reserved.

A three-dimensional thermal and electromagnetic model of whole limb heating with a MAPA.

PubMed

Charny, C K; Levin, R L

1991-10-01

Previous studies by the authors have shown that if properly implemented, the Pennes assumptions can be applied to quantify bioheat transfer during extremity heating. Given its relative numerical simplicity and its ability to predict temperatures in thermoregulated tissue, the Pennes model of bioheat transfer was utilized in a three-dimensional thermal model of limb heating. While the arterial blood temperature was assumed to be radially uniform within a cross section of the limb, axial gradients in the arterial and venous blood temperatures were computed with this three-dimensional model. A realistically shaped, three-dimensional finite element model of a tumor-bearing human lower leg was constructed and was "attached" mathematically to the whole body thermal model of man described in previous studies by the authors. The central as well as local thermoregulatory feedback control mechanisms which determine blood perfusion to the various tissues and rate of evaporation by sweating were input into the limb model. In addition, the temperature of the arterial blood which feeds into the most proximal section of the lower leg was computed by the whole body thermal model. The variations in the shape of the tissues which comprise the limb were obtained from computerized tomography scans. Axial variations in the energy deposition patterns along the length of the limb exposed to a miniannular phased array (MAPA) applicator were also input into this model of limb heating. Results indicate that proper positioning of the limb relative to the MAPA is a significant factor in determining the effectiveness of the treatment. A patient-specific hyperthermia protocol can be designed using this coupled electromagnetic and thermal model.

Functional outcome in amputation versus limb sparing of patients with lower extremity sarcoma: a matched case-control study.

PubMed

Davis, A M; Devlin, M; Griffin, A M; Wunder, J S; Bell, R S

1999-06-01

To quantify the differences in physical disability and handicap experienced by patients with lower extremity sarcoma who required amputation for their primary tumor as compared with those treated by limb-sparing surgery. Matched case-control study. Twelve patients with amputation were matched with 24 patients treated by limb-sparing surgery on the following variables: age, gender, length of follow-up, bone versus soft-tissue tumor, anatomic site, and treatment with adjuvant chemotherapy. Patients who underwent above-knee amputation (AKA) or below-knee amputation (BKA) for primary soft-tissue or bone sarcoma, who had not developed local or systemic recurrence, and who had been followed up for at least 1 year since surgery. The Toronto Extremity Salvage Score (TESS), a measure of physical disability; the Shortform-36 (SF-36), a generic health status measure; and the Reintegration to Normal Living (RNL), a measure of handicap. Mean TESS score for the patients with amputations was 74.5 versus 85.1 for the limb-sparing patients. (p = .15). Only the physical function subscale of the SF-36 showed statistically significant differences, with means of 45 and 71.1 for the amputation versus limb-sparing groups, respectively (p = .03). The RNL for the amputation group was 84.4 versus 97 for the limb-sparing group (p = .05). Seven of the 12 patients with amputations experienced ongoing difficulty with the soft tissues overlying their stumps. There was a trend toward increased disability for those in the amputation group versus those in the limb-sparing group, with the amputation group showing significantly higher levels of handicap. These data suggest that the differences in disability between amputation and limb-sparing patients are smaller than anticipated. The differences may be more notable in measuring handicap.

Divergence in male and female manipulative behaviors with the intensification of metallurgy in Central Europe.

PubMed

Macintosh, Alison A; Pinhasi, Ron; Stock, Jay T

2014-01-01

Humeral morphology has been shown to reflect, in part, habitual manipulative behaviors in humans. Among Central European agricultural populations, long-term social change, increasing task specialization, and technological innovation all had the potential to impact patterns of habitual activity and upper limb asymmetry. However, systematic temporal change in the skeletal morphology of agricultural populations in this region has not been well-characterized. This study investigates diachronic patterns in humeral biomechanical properties and lengths among 174 adult Central European agriculturalists through the first ∼ 5400 years of farming in the region. Greater asymmetry in biomechanical properties was expected to accompany the introduction of metallurgy, particularly in males, while upper limb loading patterns were expected to be more similar between the Bronze and Iron Ages. Results revealed a divergence in the lateralization of upper limb biomechanical properties by sex between the Early/Middle Neolithic and Early/Middle Bronze Age. Neolithic females had significantly more variable properties than males in both humeri, while Bronze Age female properties became homogeneous and very symmetrical relative to the right-biased lateralization of contemporaneous males. The Bronze Age to Iron Age transition was associated with morphological change among females, with a significant increase in right-biased asymmetry and a concomitant reduction in sexual dimorphism. Relative to biomechanical properties, humeral length variation and asymmetry were low though some significant sexual dimorphism and temporal change was found. It was among females that the lateralization of humeral biomechanical properties, and variation within them, changed most profoundly through time. This suggests that the introduction of the ard and plow, metallurgical innovation, task specialization, and socioeconomic change through ∼ 5400 years of agriculture impacted upper limb loading in Central European women to a greater extent than men.

Spectroscopic Evidence of Alfvén Wave Damping in the Off-limb Solar Corona

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, G. R., E-mail: girjesh@iucaa.in

We investigate the off-limb active-region and quiet-Sun corona using spectroscopic data. The active region is clearly visible in several spectral lines formed in the temperature range of 1.1–2.8 MK. We derive the electron number density using the line ratio method, and the nonthermal velocity in the off-limb region up to the distance of 140 Mm. We compare density scale heights derived from several spectral line pairs with expected scale heights per the hydrostatic equilibrium model. Using several isolated and unblended spectral line profiles, we estimate nonthermal velocities in the active region and quiet Sun. Nonthermal velocities obtained from warm linesmore » in the active region first show an increase and then later either a decrease or remain almost constant with height in the far off-limb region, whereas nonthermal velocities obtained from hot lines show consistent decrease. However, in the quiet-Sun region, nonthermal velocities obtained from various spectral lines show either a gradual decrease or remain almost constant with height. Using these obtained parameters, we further calculate Alfvén wave energy flux in both active and quiet-Sun regions. We find a significant decrease in wave energy fluxes with height, and hence provide evidence of Alfvén wave damping. Furthermore, we derive damping lengths of Alfvén waves in the both regions and find them to be in the range of 25–170 Mm. Different damping lengths obtained at different temperatures may be explained as either possible temperature-dependent damping or by measurements obtained in different coronal structures formed at different temperatures along the line of sight. Temperature-dependent damping may suggest some role of thermal conduction in the damping of Alfvén waves in the lower corona.« less

Limb lengthening in achondroplasia.

PubMed

Chilbule, Sanjay K; Dutt, Vivek; Madhuri, Vrisha

2016-01-01

Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Nine patients aged five to 25 years (mean age 10.2 years) underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%), 9.9 cm (52.8%) and 9.6 cm (77.9%), respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3(rd) percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment). Healing index was not affected by age or bone segment. Extensive limb lengthening (more than 50% over initial length) carries significant risk and should be undertaken only after due consideration.

Stature in archeological samples from central Italy: methodological issues and diachronic changes.

PubMed

Giannecchini, Monica; Moggi-Cecchi, Jacopo

2008-03-01

Stature reconstructions from skeletal remains are usually obtained through regression equations based on the relationship between height and limb bone length. Different equations have been employed to reconstruct stature in skeletal samples, but this is the first study to provide a systematic analysis of the reliability of the different methods for Italian historical samples. Aims of this article are: 1) to analyze the reliability of different regression methods to estimate stature for populations living in Central Italy from the Iron Age to Medieval times; 2) to search for trends in stature over this time period by applying the most reliable regression method. Long bone measurements were collected from 1,021 individuals (560 males, 461 females), from 66 archeological sites for males and 54 for females. Three time periods were identified: Iron Age, Roman period, and Medieval period. To determine the most appropriate equation to reconstruct stature the Delta parameter of Gini (Memorie di metodologia statistica. Milano: Giuffre A. 1939), in which stature estimates derived from different limb bones are compared, was employed. The equations proposed by Pearson (Philos Trans R Soc London 192 (1899) 169-244) and Trotter and Gleser for Afro-Americans (Am J Phys Anthropol 10 (1952) 463-514; Am J Phys Anthropol 47 (1977) 355-356) provided the most consistent estimates when applied to our sample. We then used the equation by Pearson for further analyses. Results indicate a reduction in stature in the transition from the Iron Age to the Roman period, and a subsequent increase in the transition from the Roman period to the Medieval period. Changes of limb lengths over time were more pronounced in the distal than in the proximal elements in both limbs. 2007 Wiley-Liss, Inc.

Severe valgus deformity of the knee with permanent patellar dislocation associated with melorheostosis: a case report and review of the literature.

PubMed

Kitta, Yuki; Niki, Yasuo; Udagawa, Kazuhiko; Enomoto, Hiroyuki; Toyama, Yoshiaki; Suda, Yasunori

2014-03-01

We present a case of an 8-year-old boy diagnosed with melorheostosis who was suffering from severe genu valgum, permanent dislocation of the patella, knee flexion contracture and leg length shortening. Soft tissue contracture of the limb and subsequent joint deformities were reported to represent clinical manifestations of pediatric melorheostosis. As the epiphyseal plate had not closed, patellar reduction was achieved by soft tissue surgical stabilization, including lateral retinacular release, medial retinaculum plication, and transfer of the lateral half of the patellar tendon. At 4 years postoperatively, as a result of improved limb alignment and knee flexion contracture, the leg length shortening has improved, and the patient does not limp and participates in sports activities. Surgical intervention should be performed as early as possible, because genu valgum and external rotation of the tibia may deteriorate with age, rendering the patellar dislocation irreversible in patients with melorheostosis before epiphyseal closure. Copyright © 2012 Elsevier B.V. All rights reserved.

Stall dimensions and the prevalence of lameness, injury, and cleanliness on 317 tie-stall dairy farms in Ontario

PubMed Central

2005-01-01

Abstract The study objectives were to provide a province-wide description of stall dimensions and the aspects of cattle welfare linked to stall design in the tie-stall industry. Data on stall design; stall dimensions; and the prevalence of lameness, injury, and hind limb and udder cleanliness in lactating dairy cattle were collected from a sample of 317 tie-stall farms across Ontario. The majority of the study farms (90%) had stalls with dimensions (length, width, tie-chain length, and tie rail height) that were less than the current recommendations. This may explain, in part, the prevalence of lameness measured as the prevalence of back arch (3.2%) and severe hind claw rotation (23%), hock lesions (44%), neck lesions (3.8%), broken tails (3%), dirty hind limbs (23%), and dirty udders (4.6%). Veterinarians and producers may use this information to compare farms with the industry averages and target areas in need of improvement. PMID:16454382

Three-dimensional kinematics of the lower limbs during forward ice hockey skating.

PubMed

Upjohn, Tegan; Turcotte, René; Pearsall, David J; Loh, Jonathan

2008-05-01

The objectives of the study were to describe lower limb kinematics in three dimensions during the forward skating stride in hockey players and to contrast skating techniques between low- and high-calibre skaters. Participant motions were recorded with four synchronized digital video cameras while wearing reflective marker triads on the thighs, shanks, and skates. Participants skated on a specialized treadmill with a polyethylene slat bed at a self-selected speed for 1 min. Each participant completed three 1-min skating trials separated by 5 min of rest. Joint and limb segment angles were calculated within the local (anatomical) and global reference planes. Similar gross movement patterns and stride rates were observed; however, high-calibre participants showed a greater range and rate of joint motion in both the sagittal and frontal planes, contributing to greater stride length for high-calibre players. Furthermore, consequent postural differences led to greater lateral excursion during the power stroke in high-calibre skaters. In conclusion, specific kinematic differences in both joint and limb segment angle movement patterns were observed between low- and high-calibre skaters.

Miliaria rubra of the lower limbs in underground miners.

PubMed

Donoghue, A M; Sinclair, M J

2000-08-01

This report documents a case series of miliaria rubra of the lower limbs in miners at a deep underground metalliferous mine in tropical arid Australia. During the summer months of February and March 1999, all cases of miliaria rubra of the lower limbs in underground miners seen at the mine's medical centre were clinically examined and administered a questionnaire. Twenty-five patients were seen, an incidence of 56.4 cases per million man-hours. Miliaria rubra was most often located between the ankle and knee (88% of cases). Twenty-four percent had concurrent folliculitis and 20% had concurrent tinea. Thirty-two percent had a personal history of asthma. Walking through ground-water and splashing of the legs was common. Three to 4 weeks of sedentary duties in air conditioning was generally required to achieve resolution of miliaria rubra. The incidence of miliaria rubra of the lower limbs is 38% of the incidence of heat exhaustion at the same mine. The length of disablement is greater, however. Atopics may be at increased risk of miliaria rubra. Control measures are discussed.

On the Solar Chromosphere Observed at the LIMB with Hinode

NASA Astrophysics Data System (ADS)

Judge, Philip G.; Carlsson, Mats

2010-08-01

Broadband images in the Ca II H line, from the Broadband Filter Imager (BFI) instrument on the Hinode spacecraft, show emission from spicules emerging from and visible right down to the observed limb. Surprisingly, little absorption of spicule light is seen along their lengths. We present formal solutions to the transfer equation for given (ad hoc) source functions, including a stratified chromosphere from which spicules emanate. The model parameters are broadly compatible with earlier studies of spicules. The visibility of Ca II spicules down to the limb in Hinode data seems to require that spicule emission be Doppler shifted relative to the stratified atmosphere, either by supersonic turbulent or organized spicular motion. The non-spicule component of the chromosphere is almost invisible in the broadband BFI data, but we predict that it will be clearly visible in high spectral resolution data. Broadband Ca II H limb images give the false impression that the chromosphere is dominated by spicules. Our analysis serves as a reminder that the absence of a signature can be as significant as its presence.

Stabilization of cat paw trajectory during locomotion

PubMed Central

Klishko, Alexander N.; Farrell, Bradley J.; Beloozerova, Irina N.; Latash, Mark L.

2014-01-01

We investigated which of cat limb kinematic variables during swing of regular walking and accurate stepping along a horizontal ladder are stabilized by coordinated changes of limb segment angles. Three hypotheses were tested: 1) animals stabilize the entire swing trajectory of specific kinematic variables (performance variables); and 2) the level of trajectory stabilization is similar between regular and ladder walking and 3) is higher for forelimbs compared with hindlimbs. We used the framework of the uncontrolled manifold (UCM) hypothesis to quantify the structure of variance of limb kinematics in the limb segment orientation space across steps. Two components of variance were quantified for each potential performance variable, one of which affected it (“bad variance,” variance orthogonal to the UCM, VORT) while the other one did not (“good variance,” variance within the UCM, VUCM). The analysis of five candidate performance variables revealed that cats during both locomotor behaviors stabilize 1) paw vertical position during the entire swing (VUCM > VORT, except in mid-hindpaw swing of ladder walking) and 2) horizontal paw position in initial and terminal swing (except for the entire forepaw swing of regular walking). We also found that the limb length was typically stabilized in midswing, whereas limb orientation was not (VUCM ≤ VORT) for both limbs and behaviors during entire swing. We conclude that stabilization of paw position in early and terminal swing enables accurate and stable locomotion, while stabilization of vertical paw position in midswing helps paw clearance. This study is the first to demonstrate the applicability of the UCM-based analysis to nonhuman movement. PMID:24899676

Bilateral Symmetry of Distortions of Tactile Size Perception.

PubMed

Longo, Matthew R; Ghosh, Arko; Yahya, Tasneem

2015-01-01

The perceived distance between touches on the limbs is generally bigger for distances oriented across the width of the limb than for distances oriented along the length of the limb. The present study aimed to investigate the coherence of such distortions of tactile size perception across different skin surfaces. We investigated distortions of tactile size perception on the dorsal and palmar surfaces of both the left and right hands as well as the forehead. Participants judged which of two tactile distances felt larger. One distance was aligned with the proximodistal axis (along the body), the other with the mediolateral axis (across the body). Clear distortions were found on all five skin surfaces, with stimuli oriented across the width of the body being perceived as farther apart than those oriented along the length of the body. Consistent with previous results, distortions were smaller on the palmar than on the dorsal hand surface. Distortion on the forehead was intermediate between the dorsal and palmar surfaces. There were clear correlations between distortion on the left and right hands, for both the dorsal and palmar skin surfaces. In contrast, within each hand, there was no significant correlation between the two skin surfaces. Distortion on the forehead was not significantly correlated with that on any of the other skin surfaces. These results provide evidence for bilaterally symmetric representations underlying tactile size perception. © The Author(s) 2015.

Limb lengthening in short-stature patients using monolateral and circular external fixators.

PubMed

Lie, Chester W H; Chow, W

2009-08-01

To review the results of distraction osteogenesis in short-stature patients in our centre and analyse outcomes including complications. Retrospective study. University teaching hospital, Hong Kong. Eight patients with short stature (three had achondroplasia, three constitutional short stature, and two hypochondroplasia) operated on for limb lengthening using monolateral or circular external fixators between 1995 and 2006 were reviewed. The mean age at the time of surgery was 20 years (range, 9-39 years). The fixators used were either Ilizarov or Orthofix. The average gain in length per bone segment was 5.2 cm (range, 3.2-8.0 cm), and the average percentage lengthening was 21% (range, 7.9-40%). The mean time in frame was 8 months (range, 4-14 months), and the average healing index was 48 days per cm of lengthening (18-110 days per cm). Minor complications (pin tract infection and transient joint stiffness) were common, and after excluding the latter the overall complication rate was 0.6 per bone segment. In our series, limb lengthening of up to 40% of the initial length of the bone segment can be achieved without significant long-term sequelae. However, the procedures were complex and prolonged, and required a special psychological approach directed at both parents and the patients. Complications are quite common, for which patients have to be well prepared before starting the procedures.

Architectural analysis and predicted functional capability of the human latissimus dorsi muscle.

PubMed

Gerling, Michael E; Brown, Stephen H M

2013-08-01

The latissimus dorsi is primarily considered a muscle with actions at the shoulder, despite its widespread attachments at the spine. There is some dispute regarding the potential contribution of this muscle to lumbar spine function. The architectural design of a muscle is one of the most accurate predictors of muscle function; however, detailed architectural data on the latissimus dorsi muscle are limited. Therefore, the aim of this study was to quantify the architectural properties of the latissimus dorsi muscle and model mechanical function in light of these new data. One latissimus dorsi muscle was removed from each of 12 human cadavers, separated into regions, and micro-dissected for quantification of fascicle length, sarcomere length, and physiological cross-sectional area. From these data, sarcomere length operating ranges were modelled to determine the force-length characteristics of latissimus dorsi across the spine and shoulder ranges of motion. The physiological cross-sectional area of latissimus dorsi was 5.6±0.5 cm2 and normalized fascicle length was 26.4±1.0 cm, indicating that this muscle is designed to produce a moderate amount of force over a large range of lengths. Measured sarcomere length in the post-mortem neutral spine posture was nearly optimal at 2.69±0.06 μm. Across spine range of motion, biomechanical modelling predicted latissimus dorsi acts across both the ascending and descending limbs of the force-length curve during lateral bend, and primarily at or near the plateau region (where maximum force generation is possible) during flexion/extension and axial twist. Across shoulder range of motion, latissimus dorsi acts primarily on the plateau region and descending limbs of the force length curve during both flexion/extension and abduction/adduction. These data provide novel insights into the ability of the latissimus dorsi muscle to generate force and change length throughout the spine and shoulder ranges of motion. In addition, these findings provide an improved understanding of the spine and shoulder positions at which the force-generating capacity of this muscle can become jeopardized, and consequently how this may affect its spine-stabilizing ability. © 2013 Anatomical Society.

Architectural analysis and predicted functional capability of the human latissimus dorsi muscle

PubMed Central

Gerling, Michael E; Brown, Stephen H M

2013-01-01

The latissimus dorsi is primarily considered a muscle with actions at the shoulder, despite its widespread attachments at the spine. There is some dispute regarding the potential contribution of this muscle to lumbar spine function. The architectural design of a muscle is one of the most accurate predictors of muscle function; however, detailed architectural data on the latissimus dorsi muscle are limited. Therefore, the aim of this study was to quantify the architectural properties of the latissimus dorsi muscle and model mechanical function in light of these new data. One latissimus dorsi muscle was removed from each of 12 human cadavers, separated into regions, and micro-dissected for quantification of fascicle length, sarcomere length, and physiological cross-sectional area. From these data, sarcomere length operating ranges were modelled to determine the force–length characteristics of latissimus dorsi across the spine and shoulder ranges of motion. The physiological cross-sectional area of latissimus dorsi was 5.6 ± 0.5 cm2 and normalized fascicle length was 26.4 ± 1.0 cm, indicating that this muscle is designed to produce a moderate amount of force over a large range of lengths. Measured sarcomere length in the post-mortem neutral spine posture was nearly optimal at 2.69 ± 0.06 μm. Across spine range of motion, biomechanical modelling predicted latissimus dorsi acts across both the ascending and descending limbs of the force–length curve during lateral bend, and primarily at or near the plateau region (where maximum force generation is possible) during flexion/extension and axial twist. Across shoulder range of motion, latissimus dorsi acts primarily on the plateau region and descending limbs of the force length curve during both flexion/extension and abduction/adduction. These data provide novel insights into the ability of the latissimus dorsi muscle to generate force and change length throughout the spine and shoulder ranges of motion. In addition, these findings provide an improved understanding of the spine and shoulder positions at which the force-generating capacity of this muscle can become jeopardized, and consequently how this may affect its spine-stabilizing ability. PMID:23758053

Biometric analysis of the clinical crown and the width/length ratio in the maxillary anterior region.

PubMed

Orozco-Varo, Ana; Arroyo-Cruz, Gema; Martínez-de-Fuentes, Rafael; Jiménez-Castellanos, Emilio

2015-06-01

Restorative dentistry often involves correcting tooth size discrepancies. Therefore, dental biometrics should play an important role in the planning of an esthetic restoration. The purpose of this study was to analyze the clinical crown width, length, and width/length ratio of maxillary central incisors, lateral incisors, and canines in an adult population. The study also aimed to determine whether a correlation exists between natural tooth dimensions and the optimal tooth dimension guidelines suggested for planning esthetic restorations. Stone casts were poured from irreversible hydrocolloid impressions of 412 healthy adult participants. These casts were used to measure the maximum mesiodistal width and maximum crown-root length of the maxillary central incisors, lateral incisors, and canines with a digital precision caliper (0.01 mm). The width/length ratio was calculated for each tooth, and 40 casts were selected to test the reliability of the measuring method. The mean age of the participants in the sample was 33.94 years; 60.7% were women and 39.3% were men. The mean width value was 8.71 mm for central incisors, 6.75 mm for lateral incisors, and 7.81 mm for canines. The mean length was 10.23 mm for central incisors, 8.59 mm for lateral incisors, and 9.93 mm for canines. The average width/length ratio was 85% for central incisors and 79% for lateral incisors and canines. The data obtained from the population studied are similar to those from previous research studies with similar methodology. However, great discrepancies in the absolute values were found when compared with other studies of ideal tooth dimension guidelines on the personal preferences and the esthetic perception of dentists. The perception of what is considered natural seems to differ from what is considered esthetically perfect. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A Fourier transform method for Vsin i estimations under nonlinear Limb-Darkening laws

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levenhagen, R. S., E-mail: ronaldo.levenhagen@gmail.com

Star rotation offers us a large horizon for the study of many important physical issues pertaining to stellar evolution. Currently, four methods are widely used to infer rotation velocities, namely those related to line width calibrations, on the fitting of synthetic spectra, interferometry, and on Fourier transforms (FTs) of line profiles. Almost all of the estimations of stellar projected rotation velocities using the Fourier method in the literature have been addressed with the use of linear limb-darkening (LD) approximations during the evaluation of rotation profiles and their cosine FTs, which in certain cases, lead to discrepant velocity estimates. In thismore » work, we introduce new mathematical expressions of rotation profiles and their Fourier cosine transforms assuming three nonlinear LD laws—quadratic, square-root, and logarithmic—and study their applications with and without gravity-darkening (GD) and geometrical flattening (GF) effects. Through an analysis of He I models in the visible range accounting for both limb and GD, we find out that, for classical models without rotationally driven effects, all the Vsin i values are too close to each other. On the other hand, taking into account GD and GF, the Vsin i obtained with the linear law result in Vsin i values that are systematically smaller than those obtained with the other laws. As a rule of thumb, we apply these expressions to the FT method to evaluate the projected rotation velocity of the emission B-type star Achernar (α Eri).« less

Development and evolution of the mammalian limb: adaptive diversification of nails, hooves, and claws.

PubMed

Hamrick, M W

2001-01-01

Paleontological evidence indicates that the evolutionary diversification of mammals early in the Cenozoic era was characterized by an adaptive radiation of distal limb structures. Likewise, neontological data show that morphological variation in distal limb integumentary appendages (e.g., nails, hooves, and claws) can be observed not only among distantly related mammalian taxa but also among closely related species within the same clade. Comparative analysis of nail, claw, and hoof morphogenesis reveals relatively subtle differences in mesenchymal and epithelial patterning underlying these adult differences in distal limb appendage morphology. Furthermore, studies of regulatory gene expression during vertebrate claw development demonstrate that many of the signaling molecules involved in patterning ectodermal derivatives such as teeth, hair, and feathers are also involved in organizing mammalian distal limb appendages. For example, Bmp4 signaling plays an important role during the recruitment of mesenchymal cells into the condensations forming the terminal phalanges, whereas Msx2 affects the length of nails and claws by suppressing proliferation of germinal epidermal cells. Evolutionary changes in the form of distal integumentary appendages may therefore result from changes in gene expression during formation of mesenchymal condensations (Bmp4, posterior Hox genes), induction of the claw fold and germinal matrix (shh), and/or proliferation of epidermal cells in the claw matrix (Msx1, Msx2). The prevalence of convergences and parallelisms in nail and claw structure among mammals underscores the existence of multiple morphogenetic pathways for evolutionary change in distal limb appendages.

Multibody system of the upper limb including a reverse shoulder prosthesis.

PubMed

Quental, C; Folgado, J; Ambrósio, J; Monteiro, J

2013-11-01

The reverse shoulder replacement, recommended for the treatment of several shoulder pathologies such as cuff tear arthropathy and fractures in elderly people, changes the biomechanics of the shoulder when compared to the normal anatomy. Although several musculoskeletal models of the upper limb have been presented to study the shoulder joint, only a few of them focus on the biomechanics of the reverse shoulder. This work presents a biomechanical model of the upper limb, including a reverse shoulder prosthesis, to evaluate the impact of the variation of the joint geometry and position on the biomechanical function of the shoulder. The biomechanical model of the reverse shoulder is based on a musculoskeletal model of the upper limb, which is modified to account for the properties of the DELTA® reverse prosthesis. Considering two biomechanical models, which simulate the anatomical and reverse shoulder joints, the changes in muscle lengths, muscle moment arms, and muscle and joint reaction forces are evaluated. The muscle force sharing problem is solved for motions of unloaded abduction in the coronal plane and unloaded anterior flexion in the sagittal plane, acquired using video-imaging, through the minimization of an objective function related to muscle metabolic energy consumption. After the replacement of the shoulder joint, significant changes in the length of the pectoralis major, latissimus dorsi, deltoid, teres major, teres minor, coracobrachialis, and biceps brachii muscles are observed for a reference position considered for the upper limb. The shortening of the teres major and teres minor is the most critical since they become unable to produce active force in this position. Substantial changes of muscle moment arms are also observed, which are consistent with the literature. As expected, there is a significant increase of the deltoid moment arms and more fibers are able to elevate the arm. The solutions to the muscle force sharing problem support the biomechanical advantages attributed to the reverse shoulder design and show an increase in activity from the deltoid, teres minor, and coracobrachialis muscles. The glenohumeral joint reaction forces estimated for the reverse shoulder are up to 15% lower than those in the normal shoulder anatomy. The data presented here complements previous publications, which, all together, allow researchers to build a biomechanical model of the upper limb including a reverse shoulder prosthesis.

Is bilateral lower limb lengthening appropriate for achondroplasia?: midterm analysis of the complications and quality of life.

PubMed

Kim, Seung-Ju; Balce, Gracia Cielo; Agashe, Mandar Vikas; Song, Sang-Heon; Song, Hae-Ryong

2012-02-01

Use of the Ilizarov technique for limb lengthening in patients with achondroplasia is controversial, with a high risk of complications balancing cosmetic gains. Although several articles have described the complications of this procedure and satisfaction of patients after surgery, it remains unclear whether lengthening improves the quality of life (QOL) of these patients. We asked whether bilateral lower limb lengthenings with deformity correction in patients with achondroplasia would improve QOL and investigated the correlation between complication rate and QOL. We retrospectively reviewed 22 patients (average age, 12.7 years) diagnosed with achondroplasia who underwent bilateral lower limb lengthenings between 2002 and 2005. These patients were compared with 22 patients with achondroplasia for whom limb lengthening was not performed. The two groups were assessed using the American Academy of Orthopaedic Surgeons (AAOS) lower limb, SF-36, and Rosenberg self-esteem scores. Minimum followup was 4.5 years (range, 4.5-6.9 years). Among the lengthening group, the average gain in length was 10.21 ± 2.39 cm for the femur and 9.13 ± 2.12 cm for the tibia. A total of 123 complications occurred in these 88 segments. The surgical group had higher Rosenberg self-esteem scores than the nonsurgical group although there were no differences in the AAOS and the SF-36 scores. The self-esteem scores decreased with the increase in the number of complications. Our data suggest that despite frequent complications, bilateral lower limb lengthening increases patients' QOL. We believe lengthening is a reasonable option in selected patients. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Exercise mitigates the stunting effect of cold temperature on limb elongation in mice by increasing solute delivery to the growth plate

PubMed Central

Williams, Rebecca M.; Farnum, Cornelia E.

2010-01-01

Ambient temperature and physical activity modulate bone elongation in mammals, but mechanisms underlying this plasticity are a century-old enigma. Longitudinal bone growth occurs in cartilaginous plates, which receive nutritional support via delivery of solutes from the vasculature. We tested the hypothesis that chronic exercise and warm temperature promote bone lengthening by increasing solute delivery to the growth plate, measured in real time using in vivo multiphoton microscopy. We housed 68 weanling female mice at cold (16°C) or warm (25°C) temperatures and allowed some groups voluntary access to a running wheel. We show that exercise mitigates the stunting effect of cold temperature on limb elongation after 11 days of wheel running. All runners had significantly lengthened limbs, regardless of temperature, while nonrunning mice had shorter limbs that correlated with housing temperature. Tail length was impacted only by temperature, indicating that the exercise effect was localized to limb bones and was not a systemic endocrine reaction. In vivo multiphoton imaging of fluoresceinated tracers revealed enhanced solute delivery to tibial growth plates in wheel-running mice, measured under anesthesia at rest. There was a minimal effect of rearing temperature on solute delivery when measured at an intermediate room temperature (20°C), suggesting that a lasting increase in solute delivery is an important factor in exercise-mediated limb lengthening but may not play a role in temperature-mediated limb lengthening. These results are relevant to the study of skeletal evolution in mammals from varying environments and have the potential to fundamentally advance our understanding of bone elongation processes. PMID:20930127

EFFECT OF SIZE OF INTESTINAL DIVERSIONS IN OBESE PATIENTS WITH METABOLIC SYNDROME SUBMITTED TO GASTRIC BYPASS.

PubMed

Ramos, Rafael Jacques; Mottin, Cláudio Corá; Alves, Letícia Biscaino; Benzano, Daniela; Padoin, Alexandre Vontobel

There is no consensus on the ideal size of intestinal loops in gastric bypass of bariatric surgeries. To evaluate the metabolic outcome of patients submitted to gastric bypass with alimentary and biliopancreatic loops of different sizes. Was conducted a retrospective cohort study in diabetic obese patients (BMI≥35 kg/m2) with metabolic syndrome submitted to gastric bypass. The patients were divided into three groups according to the size of the intestinal loop: group 1, biliopancreatic limb 50 cm length and alimentary limb 100 cm length; group 2 , biliopancreatic limb 50 cm length and alimentary limb 150 cm length; and group 3, biliopancreatic limb 100 cm length and alimentary limb 150 cm length. The effect of gastric bypass with different sizes of intestinal loops in relation to the parameters that define metabolic syndrome was determined. Sixty-three patients were evaluated, and they had a mean age of 44.7±9.4 years. All were diabetics, with 62 (98.4%) being hypertensive and 51 (82.2%) dyslipidemic. The three groups were homogeneous in relation to the variables. In 24 months, there was a remission of systemic arterial hypertension in 65% of patients in group 1, 62.5% in group 2 and 68.4% in group 3. Remission of diabetes occurred in 85% of patients in group 1, 83% in group 2 and 84% in group 3. There was no statistical difference in %LEW between the groups, and waist measurements decreased in a homogeneous way in all groups. The size of loops also had no influence on the improvement in dyslipidemia. Variation in size of intestinal loops does not appear to influence improvement in metabolic syndrome in this group of patients. Não há consenso sobre o tamanho ideal das alças intestinais no bypass gástrico em Y-de-Roux em cirurgias bariátricas. Avaliar os desfechos metabólicos de pacientes submetidos ao bypass gástrico com alça intestinal alimentar e biliopancreática de tamanhos diferentes. Realizou-se coorte retrospectiva em pacientes obesos (IMC≥35 kg/m2) diabéticos com síndrome metabólica submetidos ao bypass gástrico em Y-de-Roux. Foram divididos em três grupos conforme a dimensão das alças intestinais: grupo 1, alça biliopancreática de 50 cm e alça alimentar de 100 cm; grupo 2, alça biliopancreática de 50 cm e alça alimentar de 150 cm e grupo 3, alça biliopancreática de 100 cm e alça alimentar de 150 cm. Foram avaliados os parâmetros que compõem a síndrome metabólica. Incluíram-se 63 pacientes, com média de idade de 44.7±9.4 anos. Todos eram diabéticos, 62 (98.4%) hipertensos e 51 (82.2%) dislipidêmicos. Os três grupos eram homogêneos em relação às variáveis estudadas. Em 24 meses houve remissão da hipertensão arterial sistêmica em 65% do grupo 1, 62.5% no grupo 2 e 68.4% no grupo 3. A remissão do diabete melito tipo 2 ocorreu em 85% dos pacientes do grupo 1, 83% no grupo 2, e 84% no grupo 3. Não houve diferença estatística na porcentagem de perda do excesso de peso entre os grupos e as medidas da cintura abdominal reduziram de forma homogênea em todos os grupos. A dimensão das alças também não influenciou na melhora da dislipidemia. A variação da dimensão das alças intestinais não influenciou na melhora da síndrome metabólica neste grupo de pacientes.

Polarizing PVC--A Discrepant Event

ERIC Educational Resources Information Center

Headly, David; Karabatek, Mohamed

2016-01-01

This article describes an experiment teaching polarization phenomena and the Triboelectric Series in a unit on electrostatics. Using rods (2-3 ft in length) made from wood, aluminum, PVC, and Plexiglas on an inverted watch glass, these items demonstrated to the class how a party balloon rubbed with fake rabbit fur (charging the balloon negative)…

Leg length discrepancy and osteoarthritis in the knee, hip and lumbar spine

PubMed Central

Murray, Kelvin J.; Azari, Michael F.

2015-01-01

Osteoarthritis (OA) is an extremely common condition that creates substantial personal and health care costs. An important recognised risk factor for OA is excessive or abnormal mechanical joint loading. Leg length discrepancy (LLD) is a common condition that results in uneven and excessive loading of not only knee joints but also hip joints and lumbar motion segments. Accurate imaging methods of LLD have made it possible to study the biomechanical effects of mild LLD (LLD of 20mm or less). This review examines the accuracy of these methods compared to clinical LLD measurements. It then examines the association between LLD and OA of the joints of the lower extremity. More importantly, it addresses the largely neglected association between LLD and degeneration of lumbar motion segments and the patterns of biomechanical changes that accompany LLD. We propose that mild LLD may be an important instigator or contributor to OA of the hip and lumbar spine, and that it deserves to be rigorously studied in order to decrease OA’s burden of disease. PMID:26500356

JetStream Rotational and Aspiration Atherectomy in Treating In-Stent Restenosis of the Femoropopliteal Arteries: Results of the JETSTREAM-ISR Feasibility Study.

PubMed

Shammas, Nicolas W; Shammas, Gail A; Banerjee, Subhash; Popma, Jeffrey J; Mohammad, Atif; Jerin, Michael

2016-04-01

To evaluate the outcomes and stent-device interaction of the JetStream atherectomy device in the treatment of in-stent restenosis (ISR) of the femoropopliteal segment. The JetStream XC atherectomy device, a rotational cutter with aspiration capacity, was evaluated in a prospective cohort of 29 patients (mean age 69.9 ± 11.7 years; 11 men) with femoropopliteal ISR in 32 limbs (ClinicalTrials.gov identifier NCT01722877). Lesion length was 17.4 ± 13.1 cm. The primary effectiveness outcome was acute success (≤ 30% residual narrowing with no serious adverse events). The primary safety endpoint was major adverse events. Secondary endpoints included clinically driven target lesion revascularization (TLR) at 6 months and 1 year and loss of stent integrity as assessed by an angiographic core laboratory. Treated length was 19.5 ± 12.9 cm. Acute success was obtained in 29/32 (91%) limbs. Acute device success (<50% residual narrowing after atherectomy alone) was 76% (22/29). Adjunctive balloon angioplasty was performed in all cases at a mean pressure of 11.6 ± 3.3 atm. Embolic filter protection was used in 16 (50%) of 32 limbs. Macrodebris was noted in 2 (12%) of 16 filters. Distal embolization requiring treatment occurred in 3/32 (9.4%) limbs (2 with no filter). Other non-procedure-related adverse events were 1 (3%) death (nonvascular) and 1 (3%) case of major bleeding. There were no new stent fractures or deformities (n=24) postatherectomy. Follow-up was completed on 27 patients (29 limbs) at 6 and 12 months. TLR at these time points occurred in 4/29 (14%) and 12/29 (41%) patients. Patency (duplex-derived peak systolic velocity ratio <2.4) was 72% at 6 months. JetStream atherectomy using the XC device has favorable acute results in treating femoropopliteal ISR with high procedure success, no device-stent interaction, and favorably low TLR rates. A multicenter trial is needed to confirm these results. © The Author(s) 2016.

Can the recovery of lower limb fractures be achieved by use of 3D printing mirror model?

PubMed

Zhang, Wenxi; Ji, Yueping; Wang, Xinming; Liu, Jie; Li, Dong

2017-11-01

The mirror imaging 3D printing model can be used a as a reference for anatomical reduction in unilateral lower limb fractures. However, the premise of using mirror technology is that the bilateral lower limb bones are similar enough. Because one side had a fracture, it was impossible to compare this directly to the other side. Usually, surgeons think that the bilateral bones are symmetrical and use mirror technology without judging their symmetry. In patients with a unilateral lower limb bone fracture, we measured the long axis and short axis of the three selected transverse sections of the bilateral long bone for comparison to judge the symmetry of the bilateral long bones on CT images. Then, we printed a life-size normal mirror image of the long bone that is similar to the affected side. The model was used as a reference for the anatomical reduction of fractures and preoperative practice. Seventy-eight patients with lower limb bone fracture were included in this study. 24 groups of data were generated according to the same level and same axis. There were significant differences between the short axis of the left and right femoral condyle 5cm from the intercondylar keel (p=0.011), and the short axis of the distal tibia 15cm from the ankle dome (p=0.026). There was no significant difference between the left and right sides in the other 22 groups. Of all of the patients in our research, 3 patients decided to forego the surgical treatment and the operation was performed on the model instead, and the lengths of 2 patients showed deviation in actual operations, preventing anatomical reduction. The remaining 73 patients used the pre-bended plates and screws from preoperative practice in the actual operations, and postoperative X-ray examinations showed that the length of the deviation was within the permissible range. The "Comparison of long axis and short axis of three equidistant transverse sections" method makes it easy to judge the symmetry of the bilateral long bones, and prevents the blindness of preoperative planning using the contralateral mirror model directly. Copyright © 2017 Elsevier Ltd. All rights reserved.

What is missing between model and Aura MLS observations in mesospheric OH?

NASA Astrophysics Data System (ADS)

Wang, S.; Li, K. F.; Zeng, Z.; Sander, S. P.; Shia, R. L.; Yung, Y. L.

2017-12-01

Recent Aura Microwave Limb Souder observations show higher mesospheric OH levels than earlier versions and previous satellite observations. The current photochemical model with standard chemistry is not able to accurately simulate MLS OH in the mesosphere. In particular, the model significantly underestimates OH over the altitude range of 60-80km. In the standard middle atmospheric chemistry, HOx over this altitude range is controled mainly through the reactions of H2O + hv (< 205 nm) → H + OH; H + O2 + M → HO2 + M; and OH + HO2 → H2O + O2. In an attempt to resolve the model-observation discrepancy, we adjust the rate coefficients of these reactions within recommended uncertainty ranges using an objective Bayesian approach. However, reasonable perturbations to these reactions are not capable of resolving the mesospheric discrepancy without introducing disagreements in other regions of the atmosphere. We explore possible new reactions in the Earth's atmosphere that are not included in current standard models. Some candidate reactions and their potential impacts on mesospheric HOx chemistry will be discussed. Our results urge new laboratory studies of these candidate reactions, whose rate coefficients have never been measured for the atmospheric conditions.

Use of Negative Pressure Wound Therapy for Lower Limb Bypass Incisions.

PubMed

Tan, Kah Wei; Lo, Zhiwen Joseph; Hong, Qiantai; Narayanan, Sriram; Tan, Glenn Wei Leong; Chandrasekar, Sadhana

2017-12-25

Objective : The use of negative pressure wound therapy (NPWT) for post-surgical cardiothoracic, orthopedic, plastic, and obstetric and gynecologic procedures has been described. However, there are no data regarding its use for lower limb bypass incisions. We aimed to investigate the outcomes of NPWT in preventing surgical site infection (SSI) in patients with lower limb arterial bypass incisions. Materials and Methods : We retrospectively used data of 42 patients who underwent lower limb arterial bypass with reversed great saphenous vein between March 2014 and June 2016 and compared conventional wound therapy and NPWT with regard to preventing SSI. Results : Twenty-eight (67%) patients underwent conventional wound therapy and 14 (33%) underwent NPWT. There were no statistical differences regarding patient characteristics and mean SSI risk scores between the two patient groups (13.7% for conventional wound therapy vs. 13.4% for NPWT; P=0.831). In the conventional group, nine instances of SSI (32%) and three (11%) of these required subsequent surgical wound debridement, whereas in the NPWT group, there was no SSI incidence (P=0.019). Secondary outcomes such as the length of hospital stay, 30-day readmission rate, and need for secondary vascular procedures were not statistically different between the two groups. Conclusion : The use of NPWT for lower limb arterial bypass incisions is superior to that of conventional wound therapy because it may prevent SSIs.

[Posturographic study of total prostheses in the leg. Apropos of 88 patients examined].

PubMed

Lord, G; Gentaz, R; Gagey, P M; Baron, J B

1976-01-01

By suppressing certain articular sensory receptors, the reconstructive surgery of joints using total prostheses modifies tonic postural activity and, by this means, alters the regulation of balance in the subjects of operation. This doubtless explains certain discrepancies between the apparently excellent results in respect of joint movement and muscle strength and poor utilisation of the joint in every day life (instability, use of sticks or failure to use the joint in walking). Drawing on the experience and basic work of specialists in posture, the authors have undertaken a study of tonic postural activity in patients who had received a total prosthesis in the lower limb, both from the clinical aspect and by graphic measurement using an electronic apparatus, the statokinesiometer. Fourteen normal subjects were tested to calibrate the apparatus and 8 patients suffering from established osteoarthritis of the hip were studied as controls. Analysis of tonic postural activity was made in 66 patients who had received total prostheses in the lower limb. The results showed significant disturbance in balance in ankle prostheses, minimal disturbance in knee prostheses and not significant disturbance in hip prostheses. Certain therapeutic implications are derived from this study.

Comparing the surgical timelines of military and civilians traumatic lower limb amputations

PubMed Central

Staruch, R.M.T.; Jackson, P.C.; Hodson, J.; Yim, G.; Foster, M.A.; Cubison, T.; Jeffery, S.L.A.

2016-01-01

The care and challenges of injured service have been well documented in the literature from a variety of specialities. The aim of this study was to analyse the surgical timelines of military and civilian traumatic amputees and compare the surgical and resuscitative interventions. A retrospective review of patient notes was undertaken. Military patients were identified from the Joint Theatre Trauma Registry (JTTR) in 2009. Civilian patients were identified using the hospital informatics database. Patient demographics, treatment timelines as well as surgical and critical care interventions were reviewed. In total 71 military patients sustained traumatic amputations within this time period. This represented 11% of the total injury demographic in 2009. Excluding upper limb amputees 46 patients sustained lower extremity amputations. These were investigated further. In total 21 civilian patients were identified in a 7-year period. Analysis revealed there was a statistically significant difference between patient age, ITU length of stay, blood products used and number of surgical procedures between military and civilian traumatic amputees. This study identified that military patients were treated for longer in critical care and required more surgical interventions for their amputations. Despite this, their time to stump closure and length of stay were not statistically different compared to civilian patients. Such observations reflect the importance of an Orthoplastic approach, as well as daily surgical theatre co-ordination and weekly multi-disciplinary meetings in providing optimal care for these complex patients. This study reports the epidemiological observed differences between two lower limb trauma groups. PMID:26958343

Changes of cerebrospinal fluid protein concentrations and gait patterns in geriatric normal pressure hydrocephalus patients after ventriculoperitoneal shunting surgery.

PubMed

Chen, Carl P C; Huang, Yin-Cheng; Chang, Chen-Nen; Chen, Jean-Lon; Hsu, Chih-Chin; Lin, Wan-Ying

2018-06-01

Normal pressure hydrocephalus (NPH) was the first type of dementia ever described that can be treated using ventriculoperitoneal shunting surgery. Three typical clinical symptoms of NPH include gait disturbance, progressive cognitive dysfunction, and urinary incontinence. Although there are articles that have discovered several cerebrospinal fluid (CSF) protein biomarkers associated with NPH; however, studies examining individual and total protein concentrations from the ventricular CSF before and after shunting surgery are lacking. This study used proteomics to calculate the CSF individual and total protein concentrations before, and one week, one month and three months after the shunting surgery. Parameters of cadence, step length, walking speed, and percentages of single- and double-limb support in a gait cycle were measured. Protein concentrations associated with anti-oxidation, aging, and in the prevention of neurotoxic agent production increased by at least 2-folds after the surgery, indicating that the brain may become less susceptible to neurodegeneration. These proteins were alpha-1B-glycoprotein, apolipoproteins A-1 & A-IV, prostaglandin-H2 D-isomerase, alpha-1-antitrypsin, and serotransferrin. In gait analysis, lower cadence, decreased double-limb support, longer step length, and increased single-limb support were observed after the surgery, indicating a more stable walking balance. These changes lasted for a period of at least 3 months. As a result, shunting surgery may be recommended for geriatric patients with confirmed diagnosis of normal pressure hydrocephalus. Copyright © 2018 Elsevier Inc. All rights reserved.

Differentiation of cartilaginous anlagen in entire embryonic mouse limbs cultured in a rotating bioreactor

NASA Astrophysics Data System (ADS)

Montufar-Solis, D.; Oakley, C. R.; Jefferson, Y.; Duke, P. J.

2003-10-01

Mechanisms involved in development of the embryonic limb have remained the same throughout eons of genetic and environmental evolution under Earth gravity (lg). During the spaceflight era it has been of interest to explore the ancient theory that form of the skeleton develops in response to gravity, and that changes in gravitational forces can change the developmental pattern of the limb. This has been shown in vivo and in vitro, allowing the hypergravity of centrifugation and microgravity of space to be used as tools to increase our knowledge of limb development. In recapitulations of spaceflight experiments, premetatarsals were cultured in suspension in a bioreactor, and found to be shorter and less differentiated than those cultured in standard culture dishes. This study only measured length of the metatarsals, and did not account for possible changes due to the skeletal elements having a more in vivo 3D shape while in suspension vs. flattened tissues compressed by their own weight. A culture system with an outcome closer to in vivo and that supports growth of younger limb buds than traditional systems will allow studies of early Hox gene expression, and contribute to the understanding of very early stages of development. The purpose of the current experiment was to determine if entire limb buds could be cultured in the bioreactor, and to compare the growth and differentiation with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were cultured for six days, either in the bioreactor or in center-well organ culture dishes, fixed, and embedded for histology. E13 specimens grown in culture dishes were flat, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections showed excellent cartilage differentiation in both culture systems, with more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Younger limb buds fused together during culture, so an additional set of El 1.5 limb buds was cultured with and without encapsulation in alginate prior to culturing in the bioreactor. Encapsulated limbs grown in the bioreactor did not fuse together, but developed only the more proximal elements while limbs grown in culture dishes formed proximal and distal elements. Alginate encapsulation may have reduced oxygenation to the progress zone of the developing limb bud resulting in lack of development of the more distal elements. These results show that the bioreactor supports growth and differentiation of skeletal elements in entire E13 limb buds, and that a method to culture younger limb buds without fusing together needs to be developed if any morphometric analysis is to be performed.

Description of a new species of the costata-group (Cladocera, Chydoridae, Aloninae) from Brazil.

PubMed

Sousa, Francisco Diogo R; Santos, Sandro; Güntzel, Adriana Maria; Diniz, Leidiane Pereira; De Melo Júnior, Mauro; Elmoor-Loureiro, Lourdes M A

2015-11-12

The aim of this study is to describe a new species of the costata-group from Brazil. Alona margipluma sp. nov. shares morphological traits with A. costata Sars, 1862, A. natalensis Sinev, 2008, and A. cheni Sinev, 1999, but differs from them in: (i) thin setulae between the marginal setae on the valves, (ii) setae 4-5 on the exopodite of limb III long and different in length, (iii) bottle-shaped sensillum on the basal endite of limb IV. For identification of Alona margipluma sp. nov. it is necessary to check carefully the main head pores and postabdomen characters since the former superficially resemble A. iheringula, A. setigera and Alona guttata.

Terahertz atmospheric attenuation and continuum effects

NASA Astrophysics Data System (ADS)

Slocum, David M.; Goyette, Thomas M.; Slingerland, Elizabeth J.; Giles, Robert H.; Nixon, William E.

2013-05-01

Remote sensing over long path lengths has become of greater interest in the terahertz frequency region. Applications such as pollution monitoring and detection of energetic chemicals are of particular interest. Although there has been much attention to atmospheric effects over narrow frequency windows, accurate measurements across a wide spectrum is lacking. The water vapor continuum absorption spectrum was investigated using Fourier Transform Spectroscopy. The continuum effect gives rise to an excess absorption that is unaccounted for in just a resonant line spectrum simulation. The transmission of broadband terahertz radiation from 0.300THz - 1.5THz through air with varying relative humidity levels was recorded for multiple path lengths. From these data, the absorption coefficient as a function of frequency was determined and compared with model calculations. The intensity and location of the strong absorption lines were in good agreement with spectral databases such as the 2008 HITRAN database and the JPL database. However, a noticeable continuum effect was observed particularly in the atmospheric transmission windows. A small discrepancy still remained even after accounting for continuum absorption using the best available data from the literature. This discrepancy, when projected over a one kilometer path length, typical of distances used in remote sensing, can cause a 30dB difference between calculated and observed attenuation. From the experimental and resonant line simulation spectra the air-broadening continuum parameter was calculated and compared with values available in the literature.

Speciation genes in the genus Petunia

PubMed Central

Venail, Julien; Dell'Olivo, Alexandre; Kuhlemeier, Cris

2010-01-01

A major innovation in angiosperms is the recruitment of animal pollinators as a means to enhance the efficiency and specificity of pollen transfer. The implementation of this reproductive strategy involved the rapid and presumably coordinated evolution of multiple floral traits. A major question concerns the molecular identity of the genetic polymorphisms that specify the phenotypic differences between distinct pollination syndromes. Here, we report on our work with Petunia, an attractive model system for quantitative plant genetics and genomics. From interspecific crosses, we obtained F2 plants that differed in the length of the floral tube or the size of the limb. We used these plants to study the behaviour of the hawkmoth pollinator, Manduca sexta. Plants with larger limbs were preferentially visited, consistent with the notion that flower size affects visibility under low light conditions. The moths also displayed an innate preference for shorter tubes. However, in those cases that flowers with long tubes were chosen, the animals fed for equal time. Thus, the perception of tube length may help the moths, early on, to avoid those plants that are more difficult to handle. PMID:20047872

Vibration isolation by exploring bio-inspired structural nonlinearity.

PubMed

Wu, Zhijing; Jing, Xingjian; Bian, Jing; Li, Fengming; Allen, Robert

2015-10-08

Inspired by the limb structures of animals/insects in motion vibration control, a bio-inspired limb-like structure (LLS) is systematically studied for understanding and exploring its advantageous nonlinear function in passive vibration isolation. The bio-inspired system consists of asymmetric articulations (of different rod lengths) with inside vertical and horizontal springs (as animal muscle) of different linear stiffness. Mathematical modeling and analysis of the proposed LLS reveal that, (a) the system has very beneficial nonlinear stiffness which can provide flexible quasi-zero, zero and/or negative stiffness, and these nonlinear stiffness properties are adjustable or designable with structure parameters; (b) the asymmetric rod-length ratio and spring-stiffness ratio present very beneficial factors for tuning system equivalent stiffness; (c) the system loading capacity is also adjustable with the structure parameters which presents another flexible benefit in application. Experiments and comparisons with existing quasi-zero-stiffness isolators validate the advantageous features above, and some discussions are also given about how to select structural parameters for practical applications. The results would provide an innovative bio-inspired solution to passive vibration control in various engineering practice.

Are human hands and feet affected by climate? A test of Allen's rule.

PubMed

Betti, Lia; Lycett, Stephen J; von Cramon-Taubadel, Noreen; Pearson, Osbjorn M

2015-09-01

In recent years, several studies have shown that populations from cold, high-latitude regions tend to have relatively shorter limbs than populations from tropical regions, with most of the difference due to the relative length of the zeugopods (i.e., radius, ulna, tibia, fibula). This pattern has been explained either as the consequence of long-term climatic selection or of phenotypic plasticity, with temperature having a direct effect on bone growth during development. The aims of this study were to test whether this pattern of intra-limb proportions extended to the bones of the hands and feet, and to determine whether the pattern remained significant after taking into account the effects of neutral evolutionary processes related to population history. Measurements of the limb bones, including the first metatarsal and metacarpal, were collected for 393 individuals from 10 globally distributed human populations. The relationship between intra-limb indices and minimum temperature was tested using generalized least squares regression, correcting for spatial autocorrelation. The results confirmed previous observations of a temperature-related gradient in intra-limb proportions, even accounting for population history. This pattern extends to the hands, with populations from cold regions displaying a relatively shorter and stockier first metacarpal; however, the first metatarsal appears to be wider but not shorter in cold-adapted populations. The results suggest that climatic adaptation played a role in shaping variation in limb proportions between human populations. The different patterns shown by the hands and feet might be due to the presence of evolutionary constraints on the foot to maintain efficient bipedal locomotion. © 2015 Wiley Periodicals, Inc.

Laparoscopic Conversion of One Anastomosis Gastric Bypass to Roux-en-Y Gastric Bypass for Chronic Bile Reflux.

PubMed

Facchiano, Enrico; Leuratti, Luca; Veltri, Marco; Lucchese, Marcello

2016-03-01

One anastomosis gastric bypass (OAGB) demonstrated similar results to traditional Roux-en-Y procedures. A possible concern is how to manage a chronic bile reflux when medical therapy results ineffective. Revision of the gastro-jejunal anastomosis, obtaining a Roux-en-Y reconstruction, has already been proposed, but technical details have not been elucidated yet. This video shows how to revise a 200-cm OAGB to treat chronic bile reflux, by converting the procedure to Roux-en-Y, having a short gastric pouch and a long efferent limb. A 51-year-old patient complained of recurrent heartburns 2 months after OAGB. A gastroscopy witnessed the presence of a 6-cm long gastric pouch with pouchitis and bile reflux in esophagus. Specific medications were ineffective. He underwent a revisional laparoscopic procedure. The efferent limb was measured and consisted of 650 cm. The afferent limb was then divided next to the previous gastro-jejunal anastomosis and a jejuno-jejunal anastomosis was performed distally at 70 cm on the alimentary limb. Total operative time was 50 min. The postoperative stay was uneventful and the patient was discharged in postoperative day four. At 6 months follow-up he is still free of medications without symptoms. The ideal scenario for the presented technique is the finding of a long efferent limb, in order to fashion a Roux-en-Y limb without the risk of postoperative malabsorption. To reach this goal, we suggest the measurement of the whole small bowel intra-operatively, in order to assess the length of the common channel left in place.

WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damato, A; Devlin, P; Bhagwat, M

Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of themore » clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.« less

[Stump forming after traumatic foot amputation of a child--description of a new surgical procedure and literature review of lawnmower accidents].

PubMed

Bayer, J; Zajonc, H; Strohm, P C; Vohrer, M; Maier-Lenz, D; Südkamp, N P; Schwering, L

2009-01-01

Amputation injuries in children occur in motor vehicle, farming and, importantly, lawn mower accidents. Treatment of lawn mower related injuries is complicated by gross wound contamination, avascular tissue, soft tissue defects and exposed bone. Many treatment options exist and often an adequate prosthetic supply is needed for rehabilitation. We report on an 8-year old boy who got under a ride-on lawn mower and sustained a subtotal amputation of his right foot. After initial surgery an amputation was subsequently necessary. For this, it had to be taken into account that the traumatic loss of the talus, calcaneus and parts of the cuboid bone would result in a length shortening of the right leg and so far not injured metatarsal and tarsal bones had to be sacrificed. Thus, we aimed to develop a new operation technique to optimize stump length as well as preserve tarsal bones and the possibility of limb growth. In order to achieve this, we performed a new stump forming operation in which we integrated uninjured tarsal and metatarsal bones. First a Lisfranc's amputation was performed and a metatarsal bone was kept aside. The talus, calcaneus as well as the cuboid bone were either completely or almost completely destroyed and were removed. The remaining cuneiform bones were transfixed by a notched metatarsal bone, thus achieving a tarsal arthrodesis, and the cartilages of the proximal joint surfaces were removed. The cartilage of the cranial and caudal navicular as well as the distal tibial joint surface was also removed and an arthrodesis between the distal tibia and the navicular bone was achieved by crossed Kirschner wires. Finally the cuneiform bones were placed inferior to the navicular bone. Further stump coverage was managed by skin and muscle flaps as well as split skin graft. Our patient was discharged on day 34. A fluent gait without crutches as well as sports activities were possible again as early as 6 1/2 months after the injury. Using our stump forming technique we hope to prevent some complications of amputation injuries. Because of the intact epiphysis a bone overgrowth is hopefully prevented and growth potential is preserved and by inclusion of tarsal and metatarsal bones in the stump formation a length discrepancy is minimized. (c) Georg Thieme Verlag KG Stuttgart-New York.

The Use of 3D Printing Technology in the Ilizarov Method Treatment: Pilot Study.

PubMed

Burzyńska, Karolina; Morasiewicz, Piotr; Filipiak, Jarosław

2016-01-01

Significant developments in additive manufacturing technology have occurred in recent years. 3D printing techniques can also be helpful in the Ilizarov method treatment. The aim of this study was to evaluate the usefulness of 3D printing technology in the Ilizarov method treatment. Physical models of bones used to plan the spatial design of Ilizarov external fixator were manufactured by FDM (Fused Deposition Modeling) spatial printing technology. Bone models were made of poly(L-lactide) (PLA). Printed 3D models of both lower leg bones allow doctors to prepare in advance for the Ilizarov method treatment: detailed consideration of the spatial configuration of the external fixation, experimental assembly of the Ilizarov external fixator onto the physical models of bones prior to surgery, planning individual osteotomy level and Kirschner wires introduction sites. Printed 3D bone models allow for accurate preparation of the Ilizarov apparatus spatially matched to the size of the bones and prospective bone distortion. Employment of the printed 3D models of bone will enable a more precise design of the apparatus, which is especially useful in multiplanar distortion and in the treatment of axis distortion and limb length discrepancy in young children. In the course of planning the use of physical models manufactured with additive technology, attention should be paid to certain technical aspects of model printing that have an impact on the accuracy of mapping of the geometry and physical properties of the model. 3D printing technique is very useful in 3D planning of the Ilizarov method treatment.

Spinopelvic Fixation of Sacroiliac Joint Fractures and Fracture-Dislocations: A Clinical 8 Years Follow-Up Study.

PubMed

Sobhan, Mohammad R; Abrisham, Seyed Mohammad J; Vakili, Mahmood; Shirdel, Saeed

2016-10-01

Pelvic ring injuries and sacroiliac dislocations have significant impacts on patient's quality of life. Several techniques have been described for posterior pelvic fixation. The current study has been designed to evaluate the spinopelvic method of fixation for sacroiliac fractures and fracture-dislocations. Between January 2006 and December 2014, 14 patients with sacroiliac joint fractures, dislocation and fracture-dislocation were treated by Spinopelvic fixation at Shahid Sadoughi Training Hospital, Yazd, Iran. Patients were seen in follow up, on average, out to 32 months after surgery. Computed tomographic (CT) scans of patients with sacral fractures were reviewed to determine the presence of injuries. A functional assessment of the patients was performed using Majeed's score. Patient demographics, reduction quality, loss of fixation, outcomes and complications, return to activity, and screw hardware characteristics are described. The injury was unilateral in 11 (78.5%) patients and bilateral in 3 (21.5%). Associated injuries were present in all patients, including fractures, dislocation and abdominal injuries. Lower limb length discrepancy was less than 10 mm in all patients except two. Displacement, as a measure of quality of reduction was less than 5 mm in 13 patients. The mean Majeed score was 78/100. Wound infection and hardware failure were observed in 3 (21.4%) and 1 (7.1%) cases, respectively. In this study most patients (85%) return to work postoperatively. According to the findings, spinopelvic fixation is a safe and effective technique for treatment of sacroiliac injuries. This method can obtain early partial to full weight bearing and possibly reduce the complications.

Minimally invasive clamp-assisted reduction and cephalomedullary nailing without cerclage cables for subtrochanteric femur fractures in the elderly: Surgical technique and results.

PubMed

Mingo-Robinet, Juan; Torres-Torres, Miguel; Moreno-Barrero, María; Alonso, Juan Antonio; García-González, Sara

2015-01-01

The treatment of subtrochanteric fractures in the elderly remains technically challenging, due to instability and osteoporosis, with high reoperation rates. Even if intramedullary nailing is the most reliable treatment, reduction is difficult and cerclage wiring remains controversial. The purpose of this study was to evaluate 26 consecutive subtrochanteric fractures in elderly patients treated with a minimally invasive clamp-assisted reduction and cephalomedullary nailing without cerclage wiring. A retrospective analysis was conducted between January 2010 and September 2013. Data obtained from the medical records included patient's age, sex, classification of the fracture, the quality of reduction after surgery, and the presence of postoperative complications, especially fracture displacement and delayed union or nonunion. Twenty-six patients had adequate radiographic and clinical follow-up. Mean age was 84.4 (range 75-96) years. The mean duration of follow-up was 7.6 months (6-14 months). Mean surgical time was 74.42 min (range 45-115 min). Twenty-four (92.3%) showed acceptable varus/valgus alignment, and no sagittal plane malunions were noted. The tip-apex distance was <25 mm in all cases. Distraction at the fracture was <10mm in 21 fractures. Three patients had limb length discrepancy of 1cm. All fractures healed uneventfully. Reducing the fracture before nailing is mandatory to achieve good results. Minimally invasive clamp reduction without cerclage wires, even if challenging, has proven to be a safe, reproducible, and effective surgical technique, with at least the same results as other series. Copyright © 2015 Elsevier Ltd. All rights reserved.

Open unstable metaphyseo-diaphyseal fractures of the tibia in adolescents: treatment by flexible intramedullary nails augmented by external fixator.

PubMed

Atef, Ashraf; El Tantawy, Ahmad

2015-05-01

The treatment of open and unstable metaphyseo-diaphyseal fractures of the tibia in adolescents is challenging. It is important to choose a fixation method that can maintain alignment, allow wound care and not violate the growth plate. The aim of this work was to evaluate the efficacy of using flexible intramedullary nails (FIN) augmented by external fixator (EF) in the management of such fractures. A total of 26 males, with a mean age of 14.08 years and average body weight of 49.8 kg, presented with open metaphyseo-diaphyseal tibial fractures. All cases were treated using FIN augmented by mono-lateral EF. The fractures were located at the upper third in 17 cases and at the lower third in nine cases. The fracture pattern was spiral in eight cases, oblique in seven and multi-fragmentary in 11. The results were evaluated according to the scoring system for femoral TENs. All fractures united primarily after an average eight to 12 weeks with no evident angular deformity or limb-length discrepancy. None of the cases required cast immobilization or revision procedure. Twenty patients had excellent results, six patients showed good results and none had poor results. Fracture characteristics as well as patients' characteristics had no statistically significant effect (p > 0.005) on the final end results. The use of FIN augmented by EF is a good alternative in the management of open metaphyseo-diaphyseal tibial fractures in adolescents. This fixation provides more stability, allows easy access to the wound and early patients' ambulation.

Design of a knee joint mechanism that adapts to individual physiology.

PubMed

Jiun-Yih Kuan; Pasch, Kenneth A; Herr, Hugh M

2014-01-01

This paper describes the design of a new knee joint mechanism, called the Adaptive Coupling Joint (ACJ). The new mechanism has an adaptive trajectory of the center of rotations (COR) that automatically matches those of the attached biological joint. The detailed design is presented as well as characterization results of the ACJ. Conventional exoskeleton and assistive devices usually consider limb joints as a one to three degrees of freedom (DOFs) joint synthesized by multiple one-DOF hinge joints in a single plane. However, the biological joints are complex and usually rotate with respect to a changing COR. As a result, the mismatch between limb joint motion and mechanical interface motion can lead to forces that cause undesired ligament and muscle length changes and internal mechanical changes. These undesired changes contribute to discomfort, as well as to the slippage and sluggish interaction between humans and devices. It is shown that the ACJ can transmit planetary torques from either active or passive devices to the limbs without altering the normal biological joint motion.

Effect of limb immobilization on skeletal muscle

NASA Technical Reports Server (NTRS)

Booth, F. W.

1982-01-01

Current knowledge and questions remaining concerning the effects of limb immobilization on skeletal muscle is reviewed. The most dramatic of these effects is muscle atrophy, which has been noted in cases of muscles fixed at or below their resting length. Immobilization is also accompanied by a substantial decrease in motoneuronal discharges, which results in the conversion of slow-twitch muscle to muscle with fast-twitch characteristics. Sarcolemma effects include no change or a decrease in resting membrane potential, the appearance of extrajunctional acetylcholine receptors, and no change in acetylcholinesterase activity. Evidence of changes in motoneuron after hyperpolarization characteristics suggests that the muscle inactivity is responsible for neuronal changes, rather than vice versa. The rate of protein loss from atrophying muscles is determined solely by the first-order rate constant for degradation. Various other biochemical and functional changes have been noted, including decreased insulin responsiveness and protein synthesis. The model of limb immobilization may also be useful for related studies of muscle adaptation.

Body proportions of Homo habilis reviewed.

PubMed

Haeusler, Martin; McHenry, Henry M

2004-04-01

The ratio of fore- to hindlimb size plays an important role in our understanding of human evolution. Although Homo habilis was relatively modern craniodentally, its body proportions are commonly believed to have been more apelike than in the earlier Australopithecus afarensis. The evidence for this, however, rests, on two fragmentary skeletons, OH 62 and KNM-ER 3735. The upper limb of the better-preserved OH 62 from Olduvai Gorge is long and slender, but its hindlimb is represented mainly by the proximal portion of a thin femur of uncertain length. The present analysis shows that upper-to-lower limb shaft proportions of both OH 62 and AL 288-1 (A. afarensis) fall in the modern human range of variation, although OH 62 also falls inside that of chimpanzees due to their overlap in small individuals. Despite being more fragmentary, the larger-bodied KNM-ER 3735 lies outside the chimpanzee range and close to the human mean. Because the differences between any of the three individuals are compatible with the range of variation seen in extant hominoid groups, it is not legitimate to infer more primitive upper-to-lower limb shaft proportions for either H. habilis or A. afarensis. Femur length of OH 62 can only be estimated by comparison. Its closest match in size and morphology is with the gracile OH 34 specimen, which therefore provides a better analogue for the reconstruction of OH 62 than the stocky AL 288-1 femur that is traditionally used. OH 34's slender proportions are hardly due to abrasion, but match those of a modern human of that body-size, suggesting that the relative length of OH 62's leg may have been human-like. Brachial proportions, however, remained primitive. Long legs may imply long distance terrestrial travel. Perhaps this adaptation evolved early in the genus Homo, with H. habilis providing an early representative of this important change.

[Epiphysis preserving by physeal distraction for treatment of femur osteosarcoma in children].

PubMed

Yao, Weitao; Cai, Qiqing; Gao, Songtao; Wang, Jiaqiang; Zhang, Peng; Wang, Xin

2013-04-01

To analyze the effectiveness and application value of epiphysis preserving by the method of physeal distraction for treatment of femur osteosarcoma in children's limb saving surgery. Between January 2007 and January 2011, 6 patients with femur osteosarcoma underwent epiphysis preserving operation by physeal distraction. There were 4 males and 2 females with a mean age of 11.4 years (range, 9-14 years). The mean disease duration was 4.8 months (range, 1-9 months). The pathology confirmed osteosarcoma in all patients by core needle or open biopsy, including 1 case of osteogenic sarcoma, 1 case of chondroblastic osteogenic sarcoma, 1 case of osteoblastic osteogenic sarcoma, and 3 cases of no classified osteosarcoma. The clinical stage was IIA in 1 case and IIB in 5 cases according to the Enneking staging system. All patients received 2 cycles of neoadjuvant chemotherapy before operation. Then physeal distraction was performed for 4-7 days (mean, 5.7 days) based on Cañiadell technique. After 1-2 days of physeal distraction, massive allograft bones and interlocking intramedullary nails were used to reconstruct bone defect after tumor resection. All patients received another 4-6 cycles of chemotherapy and were followed up. Bone healing, limb discrepancy, and complications were recorded. Functional outcomes were assessed by the system of the Musculoskeletal Tumor Society (MSTS) and the range of motion (ROM) of both knee joints. Superficial infection occurred in 1 case and was cured after dressing change, and primary healing was obtained in the other patients. All 6 patients were followed up 2.5 years on average (range, 1-5 years). Symptoms of pain and swelling disappeared. No complication of allograft rejection, loosening or breaking of fixation occurred. No relapse or metastasis happened during follow-up. Bone healing was observed at the metaphysis junction in 5 cases at 6-9 months after operation and in 1 case at 14 months. Delayed union happened at the diaphysis junction in all patients. Different amount of callus formation was seen at the surface of diaphysis junction, but the fracture line remained clear at 12-48 months after operation. At last follow-up, limb discrepancy was 1-3 cm in 4 patients and 3-5 cm in 2 patients; 3 patients had compensatory scoliosis, and 2 patients had claudication. The MSTS score was 27.20 +/- 1.92, showing significant difference (t= -4.12, P=0.00) when compared with preoperative score (19.60 +/- 2.74). The ROM of affected knee was (127.00 +/- 17.89)0, showing no significant differences when compared with preoperative ROM (109.00 +/- 12.45) degrees (t= -1.84, P=0.10) and with ROM of normal knee (126.00 +/- 9.62)degrees (t= 0.11, P=0.92). Limb saving surgery by physeal distraction can be used in young patients with open epiphyseal plate, which has the advantages of simple operation, good effectiveness, and less complications.

Strategies for Managing Massive Defects of the Foot in High-Energy Combat Injuries of the Lower Extremity

DTIC Science & Technology

2010-01-01

infection, or avascular necrosis is extremely difficult. Tibiocalcaneal fusion typically leaves a patient with a leg length discrepancy unless large bone...fractures. J Orthop Trauma 2004;18(5):265–70. 37. Dennison MG, Pool RD, Simonis RB, et al. Tibiocalcaneal fusion for avascular necrosis of the talus

The Relationship between Volume Conservation and a Volume Algorithm for a Rectangular Parallelepiped.

ERIC Educational Resources Information Center

Feghali, Issa Nehme

This study was designed to investigate the relationship between the level of conservation of displaced volume and the degree to which sixth-grade children learn the volume algorithm of a cuboid, namely, volume equals weight times length times height. The problem chosen is based on an apparent discrepancy between the present school programs and…

Maternity leave, women's employment, and marital incompatibility.

PubMed

Hyde, J S; Essex, M J; Clark, R; Klein, M H

2001-09-01

This research investigated the relationship between the length of women's maternity leave and marital incompatibility, in the context of other variables including the woman's employment, her dissatisfaction with the division of household labor, and her sense of role overload. Length of leave, work hours, and family salience were associated with several forms of dissatisfaction, which in turn predicted role overload. Role overload predicted increased marital incompatibility for experienced mothers but did not for first-time mothers, for whom discrepancies between preferred and actual child care were more important. Length of maternity leave showed significant interactions with other variables, supporting the hypothesis that a short leave is a risk factor that, when combined with another risk factor, contributes to personal and marital distress.

Abelson tyrosine-protein kinase 2 regulates myoblast proliferation and controls muscle fiber length

PubMed Central

Lee, Jennifer K; Hallock, Peter T

2017-01-01

Muscle fiber length is nearly uniform within a muscle but widely different among different muscles. We show that Abelson tyrosine-protein kinase 2 (Abl2) has a key role in regulating myofiber length, as a loss of Abl2 leads to excessively long myofibers in the diaphragm, intercostal and levator auris muscles but not limb muscles. Increased myofiber length is caused by enhanced myoblast proliferation, expanding the pool of myoblasts and leading to increased myoblast fusion. Abl2 acts in myoblasts, but as a consequence of expansion of the diaphragm muscle, the diaphragm central tendon is reduced in size, likely contributing to reduced stamina of Abl2 mutant mice. Ectopic muscle islands, each composed of myofibers of uniform length and orientation, form within the central tendon of Abl2+/− mice. Specialized tendon cells, resembling tendon cells at myotendinous junctions, form at the ends of these muscle islands, suggesting that myofibers induce differentiation of tendon cells, which reciprocally regulate myofiber length and orientation. PMID:29231808

Abelson tyrosine-protein kinase 2 regulates myoblast proliferation and controls muscle fiber length.

PubMed

Lee, Jennifer K; Hallock, Peter T; Burden, Steven J

2017-12-12

Muscle fiber length is nearly uniform within a muscle but widely different among different muscles. We show that Abelson tyrosine-protein kinase 2 (Abl2) has a key role in regulating myofiber length, as a loss of Abl2 leads to excessively long myofibers in the diaphragm, intercostal and levator auris muscles but not limb muscles. Increased myofiber length is caused by enhanced myoblast proliferation, expanding the pool of myoblasts and leading to increased myoblast fusion. Abl2 acts in myoblasts, but as a consequence of expansion of the diaphragm muscle, the diaphragm central tendon is reduced in size, likely contributing to reduced stamina of Abl2 mutant mice. Ectopic muscle islands, each composed of myofibers of uniform length and orientation, form within the central tendon of Abl2 +/- mice. Specialized tendon cells, resembling tendon cells at myotendinous junctions, form at the ends of these muscle islands, suggesting that myofibers induce differentiation of tendon cells, which reciprocally regulate myofiber length and orientation.

Music-supported therapy (MST) in improving post-stroke patients' upper-limb motor function: a randomised controlled pilot study.

PubMed

Tong, Yanna; Forreider, Brian; Sun, Xinting; Geng, Xiaokun; Zhang, Weidong; Du, Huishan; Zhang, Tong; Ding, Yuchuan

2015-05-01

Music-supported therapy (MST) is a new approach for motor rehabilitation of stroke patients. Recently, many studies have demonstrated that MST improved the motor functions of post-stroke patients. However, the underlying mechanism for this effect is still unclear. It may result from repeated practice or repeated practice combined with musical stimulation. Currently, few studies have been designed to clarify this discrepancy. In this study, the application of "mute" musical instruments allowed for the study of music as an independent factor. Thirty-three post-stroke patients with no substantial previous musical training were included. Participants were assigned to either audible music group (MG) or mute music group (CG), permitting observation of music's independent effect. All subjects received the conventional rehabilitation treatments. Patients in MG (n = 15) received 20 extra sessions of audible musical instrument training over 4 weeks. Patients in CG (n = 18) received "mute" musical instrument training of the same protocol as that of MG. Wolf motor function test (WMFT) and Fugl-Meyer assessment (FMA) for upper limbs were utilised to evaluate motor functions of patients in both groups before and after the treatment. Three patients in CG dropped out. All participants in both groups showed significant improvements in motor functions of upper limbs after 4  weeks' treatment. However, significant differences in the WMFT were found between the two groups (WMFT-quality: P = 0.025; WMFT-time: P = 0.037), but not in the FMA (P = 0.448). In short, all participants showed significant improvement after 4 weeks' treatment, but subjects in MG demonstrated greater improvement than those in CG. This study supports that MST, when combined with conventional treatment, is effective for the recovery of motor skills in post-stroke patients. Additionally, it suggests that apart from the repetitive practices of MST, music may play a unique role in improving upper-limb motor function for post-stroke patients.

Determinants of midterm functional outcomes, wound healing, and resources used in a hospital-based limb preservation program.

PubMed

Ramanan, Bala; Ahmed, Ayman; Wu, Bian; Causey, Marlin W; Gasper, Warren J; Vartanian, Shant M; Reyzelman, Alexander M; Hiramoto, Jade S; Conte, Michael S

2017-12-01

The objective of this study was to assess midterm functional status, wound healing, and in-hospital resource use among a prospective cohort of patients treated in a tertiary hospital, multidisciplinary Center for Limb Preservation. Data were prospectively gathered on all consecutive admissions to the Center for Limb Preservation from July 2013 to October 2014 with follow-up data collection through January 2016. Limbs were staged using the Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) threatened limb classification scheme at the time of hospital admission. Patients with nonatherosclerotic vascular disorders, acute limb ischemia, and trauma were excluded. The cohort included 128 patients with 157 threatened limbs; 8 limbs with unstageable disease were excluded. Mean age (±standard deviation [SD]) was 66 (±13) years, and median follow-up duration (interquartile range) was 395 (80-635) days. Fifty percent (n = 64/128) of patients were readmitted at least once, with a readmission rate of 20% within 30 days of the index admission. Mean total number of admissions per patient (±SD) was 1.9 ± 1.2, with mean (±SD) cumulative length of stay (cLOS) of 17.1 (±17.9) days. During follow-up, 25% of limbs required a vascular reintervention, and 45% developed recurrent wounds. There was no difference in the rate of readmission, vascular reintervention, or wound recurrence by initial WIfI stage (P > .05). At the end of the study period, 23 (26%) were alive and nonambulatory; in 20%, functional status was missing. On both univariate and multivariate analysis, end-stage renal disease and prior functional status predicted ability to ambulate independently (P < .05). WIfI stage was associated with major amputation (P = .01) and cLOS (P = .002) but not with time to wound healing. Direct hospital (inpatient) cost per limb saved was significantly higher in stage 4 patients (P < .05 for all time periods). WIfI stage was associated with cumulative in-hospital costs at 1 year and for the overall follow-up period. Among a population of patients admitted to a tertiary hospital limb preservation service, WIfI stage was predictive of midterm freedom from amputation, cLOS, and hospital costs but not of ambulatory functional status, time to wound healing, or wound recurrence. Patients presenting with limb-threatening conditions require significant inpatient care, have a high frequency of repeated hospitalizations, and are at significant risk for recurrent wounds and leg symptoms at later times. Stage 4 patients require the most intensive care and have the highest initial and aggregate hospital costs per limb saved. However, limb salvage can be achieved in these patients with a dedicated multidisciplinary team approach. Published by Elsevier Inc.

The Relationship Between Asymmetry and Athletic Performance: A Critical Review.

PubMed

Maloney, Sean J

2018-05-08

Maloney, SJ. The relationship between asymmetry and athletic performance: A critical review. J Strength Cond Res XX(X): 000-000, 2018-Symmetry may be defined as the quality to demonstrate an exact correspondence of size, shape, and form when split along a given axis. Although it has been widely asserted that the bilateral asymmetries are detrimental to athletic performance, research does not wholly support such an association. Moreover, the research rarely seeks to distinguish between different types of bilateral asymmetry. Fluctuating asymmetries describe bilateral differences in anthropometric attributes, such as nostril width and ear size, and are thought to represent the developmental stability of an organism. There is evidence to suggest that fluctuating asymmetries may be related to impaired athletic performance, although contradictory findings have been reported. Sporting asymmetries is a term that may better describe bilateral differences in parameters, such as force output or jump height. These asymmetries are likely to be a function of limb dominance and magnified by long-standing participation within sport. Sporting asymmetries do not seem to carry a clear influence on athletic performance measures. Given the vast discrepancy in the methodologies used by different investigations, further research is warranted. Recent investigations have demonstrated that training interventions can reduce sporting asymmetries and improve performance. However, studies have not sought to determine whether the influence of sporting asymmetry is independent of improvements in neuromuscular parameters. It may be hypothesized that the deficient (weaker) limb has a greater potential for adaptation in comparison to the strong limb and may demonstrate greater responsiveness to training.

Diagnostic pitfalls in sporadic transthyretin familial amyloid polyneuropathy (TTR-FAP).

PubMed

Planté-Bordeneuve, V; Ferreira, A; Lalu, T; Zaros, C; Lacroix, C; Adams, D; Said, G

2007-08-14

Transthyretin familial amyloid polyneuropathies (TTR-FAPs) are autosomal dominant neuropathies of fatal outcome within 10 years after inaugural symptoms. Late diagnosis in patients who present as nonfamilial cases delays adequate management and genetic counseling. Clinical data of the 90 patients who presented as nonfamilial cases of the 300 patients of our cohort of patients with TTR-FAP were reviewed. They were 21 women and 69 men with a mean age at onset of 61 (extremes: 38 to 78 years) and 17 different mutations of the TTR gene including Val30Met (38 cases), Ser77Tyr (16 cases), Ile107Val (15 cases), and Ser77Phe (5 cases). Initial manifestations included mainly limb paresthesias (49 patients) or pain (17 patients). Walking difficulty and weakness (five patients) and cardiac or gastrointestinal manifestations (five patients), were less common at onset. Mean interval to diagnosis was 4 years (range 1 to 10 years); 18 cases were mistaken for chronic inflammatory demyelinating polyneuropathy, which was the most common diagnostic error. At referral a length-dependent sensory loss affected the lower limbs in 2, all four limbs in 20, and four limbs and anterior trunk in 77 patients. All sensations were affected in 60 patients (67%), while small fiber dysfunction predominated in the others. Severe dysautonomia affected 80 patients (90%), with postural hypotension in 52, gastrointestinal dysfunction in 50, impotence in 58 of 69 men, and sphincter disturbance in 31. Twelve patients required a cardiac pacemaker. Nerve biopsy was diagnostic in 54 of 65 patients and salivary gland biopsy in 20 of 30. Decreased nerve conduction velocity, increased CSF protein, negative biopsy findings, and false immunolabeling of amyloid deposits were the main causes of diagnostic errors. We conclude that DNA testing, which is the most reliable test for TTR-FAP, should be performed in patients with a progressive length-dependent small fiber polyneuropathy of unknown origin, especially when associated with autonomic dysfunction.

Feed forward and feedback control for over-ground locomotion in anaesthetized cats

NASA Astrophysics Data System (ADS)

Mazurek, K. A.; Holinski, B. J.; Everaert, D. G.; Stein, R. B.; Etienne-Cummings, R.; Mushahwar, V. K.

2012-04-01

The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based models of the step cycle each of which produced different stimulation patterns. Two configurations were implemented to restore over-ground walking in five adult anaesthetized cats using intramuscular stimulation (IMS) of the main hip, knee and ankle flexor and extensor muscles in the hind limbs. An open loop controller relied only on intrinsic timing while a hybrid-CPG controller added sensory feedback from force plates (representing limb loading), and accelerometers and gyroscopes (representing limb position). Stimulation applied to hind limb muscles caused extension or flexion in the hips, knees and ankles. A total of 113 walking trials were obtained across all experiments. Of these, 74 were successful in which the cats traversed 75% of the 3.5 m over-ground walkway. In these trials, the average peak step length decreased from 24.9 ± 8.4 to 21.8 ± 7.5 (normalized units) and the median number of steps per trial increased from 7 (Q1 = 6, Q3 = 9) to 9 (8, 11) with the hybrid-CPG controller. Moreover, within these trials, the hybrid-CPG controller produced more successful steps (step length ≤ 20 cm ground reaction force ≥ 12.5% body weight) than the open loop controller: 372 of 544 steps (68%) versus 65 of 134 steps (49%), respectively. This supports our previous preliminary findings, and affirms that physiologically based hybrid-CPG approaches produce more successful stepping than open loop controllers. The algorithm provides the foundation for a neural prosthetic controller and a framework to implement more detailed control of locomotion in the future.

Outcomes of endovascular interventions for TASC II B and C femoropopliteal lesions.

PubMed

Baril, Donald T; Marone, Luke K; Kim, Justine; Go, Michael R; Chaer, Rabih A; Rhee, Robert Y

2008-09-01

To evaluate outcomes of endovascular interventions on femoropopliteal occlusive disease and determine predictors of restenosis of Trans Atlantic Inter-Societal Consensus (TASC) II B and C lesions. All patients undergoing endovascular interventions for femoropopliteal occlusive disease between May 2003 and July 2007 were reviewed. Patient demographics, pre- and post-procedure ankle-brachial indices (ABI), and anatomic factors (including categorization by TASC II classification, lesion length, and runoff vessel status) were analyzed. Outcomes evaluated included freedom from restenoses, freedom from re-intervention, overall patency, and assisted-patency. A total of 237 total limbs were treated during the period reviewed. The study group included 108 TASC B and 32 TASC C limbs in 125 patients (mean age 73.1 +/- 10.4 years, male sex: 59%). Seventy-one percent of patients were Rutherford classification 2/3 while the remaining 29% were Rutherford classification 4/5. Mean follow-up period was 12.7 months (range, 1-52 m). Forty-one (41) limbs experienced restenosis or occlusion at a mean time of 8 months (range, 1-24 m). Freedom from restenosis/occlusion was 58.9% at 12 months and 47.9% at 24 months. Predictors of restenosis included a preoperative ABI <0.5 (hazard ratio [HR] 3.05, 95% confidence interval [CI] 1.36-6.86, P = .007) and hypercholesterolemia (HR 2.42, 95% CI 1.11-5.25, P = .025). Lesion length as a continuous variable (per centimeter) also correlated with a higher risk of restenosis (HR 1.06, 95% CI 1.00-1.12, P = .057). The overall assisted-primary and secondary-patency rates were 87% and 94% respectively at 3 years with no significant differences between TASC B and TASC C limbs. Endovascular interventions for TASC II B and C lesions are associated with restenosis/occlusion rates that are at least as good as those of open femoropopliteal bypass surgery from historical, previously published series. Furthermore, overall assisted-patency rates are excellent, although low preoperative ABIs continue to be associated with worse outcomes.

Feed forward and feedback control for over-ground locomotion in anaesthetized cats

PubMed Central

Mazurek, K A; Holinski, B J; Everaert, D G; Stein, R B; Etienne-Cummings, R; Mushahwar, V K

2012-01-01

The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based models of the step cycle each of which produced different stimulation patterns. Two configurations were implemented to restore over-ground walking in five adult anaesthetized cats using intramuscular stimulation (IMS) of the main hip, knee and ankle flexor and extensor muscles in the hind limbs. An open loop controller relied only on intrinsic timing while a hybrid-CPG controller added sensory feedback from force plates (representing limb loading), and accelerometers and gyroscopes (representing limb position). Stimulation applied to hind limb muscles caused extension or flexion in the hips, knees and ankles. A total of 113 walking trials were obtained across all experiments. Of these, 74 were successful in which the cats traversed 75% of the 3.5 m over-ground walkway. In these trials, the average peak step length decreased from 24.9 ± 8.4 to 21.8 ± 7.5 (normalized units) and the median number of steps per trial increased from 7 (Q1=6, Q3 = 9) to 9 (8, 11) with the hybrid-CPG controller. Moreover, these trials, the hybrid-CPG controller produced more successful steps (step length ≤ 20 cm; ground reaction force ≥ 12.5% body weight) than the open loop controller: 372 of 544 steps (68%) versus 65 of 134 steps (49%), respectively. This supports our previous preliminary findings, and affirms that physiologically based hybrid-CPG approaches produce more successful stepping than open loop controllers. The algorithm provides the foundation for a neural prosthetic controller and a framework to implement more detailed control of locomotion in the future. PMID:22328615

Limb lengthening in achondroplasia

PubMed Central

Chilbule, Sanjay K; Dutt, Vivek; Madhuri, Vrisha

2016-01-01

Background: Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Materials and Methods: Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Results: Nine patients aged five to 25 years (mean age 10.2 years) underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%), 9.9 cm (52.8%) and 9.6 cm (77.9%), respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3rd percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment). Healing index was not affected by age or bone segment. Conclusion: Extensive limb lengthening (more than 50% over initial length) carries significant risk and should be undertaken only after due consideration. PMID:27512222

Safety Aspects of Postanesthesia Care Unit Discharge without Motor Function Assessment after Spinal Anesthesia: A Randomized, Multicenter, Semiblinded, Noninferiority, Controlled Trial.

PubMed

Aasvang, Eske Kvanner; Jørgensen, Christoffer Calov; Laursen, Mogens Berg; Madsen, Jacob; Solgaard, Søren; Krøigaard, Mogens; Kjærsgaard-Andersen, Per; Mandøe, Hans; Hansen, Torben Bæk; Nielsen, Jørgen Ulrich; Krarup, Niels; Skøtt, Annette Elisabeth; Kehlet, Henrik

2017-06-01

Postanesthesia care unit (PACU) discharge without observation of lower limb motor function after spinal anesthesia has been suggested to significantly reduce PACU stay and enhance resource optimization and early rehabilitation but without enough data to allow clinical recommendations. A multicenter, semiblinded, noninferiority randomized controlled trial of discharge from the PACU with or without assessment of lower limb motor function after elective total hip or knee arthroplasty under spinal anesthesia was undertaken. The primary outcome was frequency of a successful fast-track course (length of stay 4 days or less and no 30-day readmission). Noninferiority would be declared if the odds ratio (OR) for a successful fast-track course was no worse for those patients receiving no motor function assessment versus those patients receiving motor function assessment by OR = 0.68. A total of 1,359 patients (98.8% follow-up) were available for analysis (93% American Society of Anesthesiologists class 1 to 2). The primary outcome occurred in 92.2% and 92.0%, corresponding to no motor function assessment being noninferior to motor function assessment with OR 0.97 (95% CI, 0.70 to 1.35). Adverse events in the ward during the first 24 h occurred in 5.8% versus 7.4% with or without motor function assessment, respectively (OR, 0.77; 95% CI, 0.5 to 1.19, P = 0.24). PACU discharge without assessment of lower limb motor function after spinal anesthesia for total hip or knee arthroplasty was noninferior to motor function assessment in achieving length of stay 4 days or less or 30-day readmissions. Because a nonsignificant tendency toward increased adverse events during the first 24 h in the ward was discovered, further safety data are needed in patients without assessment of lower limb motor function before PACU discharge.

OH-asterisk (7-5) Meinel band dayglow and nightglow measured by the SME limb scanning near infrared spectrometer - Comparison of the observed seasonal variability with two-dimensional model simulations

NASA Technical Reports Server (NTRS)

Le Texier, H.; Solomon, S.; Thomas, R. J.; Garcia, R. R.

1989-01-01

Seasonal variations of the OH-asterisk (7-5) mesospheric hydroxyl emission at 1.89 microns observed by the SME near-IR spectrometer are compared with the theoretical predictions of a two-dimensional dynamical/chemical model. The good agreement found at low latitudes for both dayglow and nightglow provides support for the model assumption that breaking gravity waves induce seasonal and latitudinal variations in diffusion. The seasonal behavior of atomic hydrogen in the upper mesosphere (related to vertical transport) and/or uncertainties in the OH Meinel band parameters are proposed as possible explanations for the discrepancy noted between model and observational data for the middle latitudes.

Discrepancy of alignment in different weight bearing conditions before and after high tibial osteotomy.

PubMed

Wang, Joon Ho; Shin, Jung Min; Kim, Hyun Ho; Kang, Seung-Hoon; Lee, Byung Hoon

2017-01-01

To evaluate the differences in the amount of varus malalignment and valgus (over) correction in relation to three different weight bearing conditions from whole leg AP radiographs (single-limb (SL) stance, double-limb (DL) stance, supine position (S)) before and after high tibial osteotomy (HTO), and to evaluate which alignment parameters affect the changes for patients in three different weight bearing conditions. A total of 40 consecutive patients (43 knees) with varus osteoarthritis underwent navigation assisted open wedge HTO. Mechanical axis angle (MA) was measured before and after surgery from hip-to-ankle radiographs taken with patients in three different weight bearing conditions. To find significant factors that affect the alignment differences, several variables including patient demographics, soft tissue laxity, pelvic obliquity, and ground mechanical axis deviation of tibia (calculated by the angle between two lines, tibial anatomical axis and weight-bearing line) were evaluated. Pre-operatively, mean MA measured on SL stance radiographs was significantly more varus than on DL stance (10.1° ± 2.4° and 8.0° ± 2.6°, respectively, p < 0.001), which was significantly more varus than on supine position (6.6° ± 2.6°, p < 0.001). Meanwhile, in patients with post-operatively valgus corrected knee, MA did not show the same pattern of change as with pre-operative varus knee. Mean MA measured on DL stance radiographs was more valgus than in supine position (-3.0 o  ± 2.4 o and -2.6 o  ± 3.1 o , p = 0.455), while mean MA on SL stance radiographs (-2.0 o  ± 2.1 o ) was significantly less valgus than on DL stance (p = 0.002). The ground mechanical axis deviation of tibia showed a significant correlation with MA difference between SL and DL stance radiographs before (β = -0.341, p = 0.045) and after surgery (β = -0.536, p = 0.001). In pre-operative varus knee, the mean MA on SL stance was changed to more varus than on DL stance, which changed to less valgus in post-operative valgus knee. The understanding in discrepancy of alignment in different weight bearing conditions before and after HTO should be considered for the appropriate realignment of the limb. Level II Prospective comparative study.

Upper Limb Assessment in Tetraplegia: Clinical, Functional and Kinematic Correlations

ERIC Educational Resources Information Center

Cacho, Enio Walker Azevedo; de Oliveira, Roberta; Ortolan, Rodrigo L.; Varoto, Renato; Cliquet, Alberto

2011-01-01

The aim of this study was to correlate clinical and functional evaluations with kinematic variables of upper limp reach-to-grasp movement in patients with tetraplegia. Twenty chronic patients were selected to perform reach-to-grasp kinematic assessment using a target placed at a distance equal to the arm's length. Kinematic variables (hand peak…

Differentiation of cartilaginous anlage in entire embryonic mouse limbs cultured in a rotating bioreactor.

NASA Astrophysics Data System (ADS)

Duke, P.; Oakley, C.; Montufar-Solis, D.

The embryonic mammalian limb is sensitive both in vivo and in vitro to changes in gravitational force. Hypergravity of centrifugation and microgravity of space decreased size of elements due to precocious or delayed chondrogenesis respectively. In recapitulating spaceflight experiments, premetatarsals were cultured in suspension in a low stress, low sheer rotating bioreactor, and found to be shorter than those cultured in standard culture dishes, and cartilage development was delayed. This study only measured length of the metatarsals, and did not account for possible changes in width and/or in form of the skeletal elements. Shorter cartilage elements in limbbuds cultured in the bioreactor may be due to the ability of the system to reproduce a more in vivo 3D shape than traditional organ cultures. Tissues subjected to traditional organ cultures become flattened by their own weight, attachment to the filter, and restrictions imposed by nutrient diffusion. The purpose of the current experiment was to determine if entire limb buds could be successfully cultured in the bioreactor, and to compare the effects on 3D shape with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were placed either in the bioreactor, in Trowell culture, or fixed as controls. Limbbuds were cultured for six days, fixed, and processed either as whole mounts or embedded for histology. Qualitative analysis revealed that the Trowell culture specimens were flattened, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections of limbbuds from both types of cultures had excellent cartilage differentiation, with apparently more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Morphometric quantitation of the cartilaginous elements for comparisons of the two culture systems was complicated due to some limb buds fusing together during culture. This problem was especially noticeable in the younger limbs, and may be rectified by embedding the limbs in a matrix (e.g. alginate) to maintain integrity of the tissue while in culture in the bioreactor. The bioreactor supported differentiation of skeletal elements in entire limbs, and maintained better external limb morphology than did the Trowell system. Supported by NIH/NIDCR Training Grant T358DE07252-08.

Bone growth, limb proportions and non-specific stress in archaeological populations from Croatia.

PubMed

Pinhasi, R; Timpson, A; Thomas, M; Slaus, M

2014-01-01

The effect of environmental factors and, in particular, non-specific stress on the growth patterns of limbs and other body dimensions of children from past populations is not well understood. This study assesses whether growth of mediaeval and post-mediaeval children aged between 0-11.5 years from Adriatic (coastal) and continental Croatia varies by region and by the prevalence and type of non-specific stress. Dental ages were estimated using the Moorrees, Fanning and Hunt (MFH) scoring method. Growth of long bone diaphyses (femur, tibia, humerus, radius and ulna) was assessed by using a composite Z-score statistic (CZS). Clavicular length was measured as a proxy for upper trunk width, distal metaphyseal width of the femur was measured as a proxy for body mass and upper and lower intra-limb indices were calculated. Differences between sub-sets sampled by (a) region and (b) active vs healed non-specific stress indicators and (c) intra-limb indices were tested by Mann--Whitney U-tests and Analysis of Covariance (ANCOVA). Adriatic children attained larger dimensions-per-age than continental children. Children with healed stress lesions had larger dimensions-per-age than those with active lesions. No inter-regional difference was found in intra-limb indices. These findings highlight the complexity of growth patterns in past populations and indicate that variation in environmental conditions such as diet and differences in the nature of non-specific stress lesions both exert a significant effect on long bone growth.

Effects of Lumbar Strengthening Exercise in Lower-Limb Amputees With Chronic Low Back Pain.

PubMed

Shin, Min Kyung; Yang, Hee Seung; Yang, Hea-Eun; Kim, Dae Hyun; Ahn, Bo Ram; Kwon, Hyup; Lee, Ju Hwan; Jung, Suk; Choi, Hyun Chul; Yun, Sun Keaung; Ahn, Dong Young; Sim, Woo Sob

2018-02-01

To analyze the effect of lumbar strengthening exercise in lower-limb amputees with chronic low back pain. We included in this prospective study 19 lower-limb amputees who had experienced low back pain for longer than 6 months. Participants were treated with 30-minute lumbar strengthening exercises, twice weekly, for 8 weeks. We used the visual analog scale (VAS), and Oswestry low back pain disability questionnaire, and measured parameters such as iliopsoas length, abdominal muscle strength, back extensor strength, and back extensor endurance. In addition, we assessed the isometric peak torque and total work of the trunk flexors and extensors using isokinetic dynamometer. The pre- and post-exercise measurements were compared. Compared with the baseline, abdominal muscle strength (from 4.4±0.7 to 4.8±0.6), back extensor strength (from 2.6±0.6 to 3.5±1.2), and back extensor endurance (from 22.3±10.7 to 46.8±35.1) improved significantly after 8 weeks. The VAS decreased significantly from 4.6±2.2 to 2.6±1.6 after treatment. Furthermore, the peak torque and total work of the trunk flexors and extensors increased significantly (p<0.05). Lumbar strengthening exercise in lower-limb amputees with chronic low back pain resulted in decreased pain and increased lumbar extensor strength. The lumbar strengthening exercise program is very effective for lower-limb amputees with chronic low back pain.

The effects of aging on the asymmetry of inter-limb transfer in a visuomotor task.

PubMed

Pan, Zhujun; Van Gemmert, Arend W A

2013-09-01

The direction of the asymmetry of inter-limb transfer has been suggested to identify the specialization of each hemisphere when performing a motor task. In an earlier study, we showed that trajectory information is only transferred from the right to the left hand, while final movement outcome-associated parameters transferred in both directions when right-hand-dominant individuals perform a motor task with visual distorted feedback. In the current study, we try to replicate this finding in young adults and test whether the asymmetry of inter-limb transfer in visuomotor task reduces in older adults, suggesting that hemispheric lateralization reduces with age. Young and older adults (all right-hand-dominant) performed a multidirectional point-to-point drawing task in which the visual feedback was rotated and the gain was increased. Half of the participants in each age group trained with the right hand and the other half trained with the left hand. Performances of both hands with non-distorted and distorted visual feedback were collected from all participants before and after the training session. The results showed that the pattern of inter-limb transfer was similar between young and older adults, i.e., inter-limb transfer is asymmetric for initial direction and symmetric for movement time and trajectory length. The results suggest that older adults retain the specialized functions of the non-dominant (right) hemisphere allowing them to program movement direction of a graphic aiming task when visual feedback is distorted.

Fluoroscopy and imageless navigation enable an equivalent reconstruction of leg length and global and femoral offset in THA.

PubMed

Weber, Markus; Woerner, Michael; Springorum, Robert; Sendtner, Ernst; Hapfelmeier, Alexander; Grifka, Joachim; Renkawitz, Tobias

2014-10-01

Restoration of biomechanics is a major goal in THA. Imageless navigation enables intraoperative control of leg length equalization and offset reconstruction. However, the effect of navigation compared with intraoperative fluoroscopy is unclear. We asked whether intraoperative use of imageless navigation (1) improves the relative accuracy of leg length and global and femoral offset restoration; (2) increases the absolute precision of leg length and global and femoral offset equalization; and (3) reduces outliers in a reconstruction zone of ± 5 mm for leg length and global and femoral offset restoration compared with intraoperative fluoroscopy during minimally invasive (MIS) THA with the patient in a lateral decubitus position. In this prospective study a consecutive series of 125 patients were randomized to either navigation-guided or fluoroscopy-controlled THA using sealed, opaque envelopes. All patients received the same cementless prosthetic components through an anterolateral MIS approach while they were in a lateral decubitus position. Leg length, global or total offset (representing the combination of femoral and acetabular offset), and femoral offset differences were restored using either navigation or fluoroscopy. Postoperatively, residual leg length and global and femoral offset discrepancies were analyzed on magnification-corrected radiographs of the pelvis by an independent and blinded examiner using digital planning software. Accuracy was defined as the relative postoperative difference between the surgically treated and the unaffected contralateral side for leg length and offset, respectively; precision was defined as the absolute postoperative deviation of leg length and global and femoral offset regardless of lengthening or shortening of leg length and offset throughout the THA. All analyses were performed per intention-to-treat. Analyzing the relative accuracy of leg length restoration we found a mean difference of 0.2 mm (95% CI, -1.0 to +1.4 mm; p = 0.729) between fluoroscopy and navigation, 0.2 mm (95 % CI, -0.9 to +1.3 mm; p = 0.740) for global offset and 1.7 mm (95 % CI, +0.4 to +2.9 mm; p = 0.008) for femoral offset. For the absolute precision of leg length and global and femoral offset equalization, there was a mean difference of 1.7 ± 0.3 mm (p < 0.001) between fluoroscopy and navigation. The biomechanical reconstruction with a residual leg length and global and femoral offset discrepancy less than 5 mm and less than 8 mm, respectively, succeeded in 93% and 98%, respectively, in the navigation group and in 54% and 95%, respectively, in the fluoroscopy group. Intraoperative fluoroscopy and imageless navigation seem equivalent in accuracy and precision to reconstruct leg length and global and femoral offset during MIS THA with the patient in the lateral decubitus position.

Microarray Analysis of microRNA Expression during Axolotl Limb Regeneration

PubMed Central

Holman, Edna C.; Campbell, Leah J.; Hines, John; Crews, Craig M.

2012-01-01

Among vertebrates, salamanders stand out for their remarkable capacity to quickly regrow a myriad of tissues and organs after injury or amputation. The limb regeneration process in axolotls (Ambystoma mexicanum) has been well studied for decades at the cell-tissue level. While several developmental genes are known to be reactivated during this epimorphic process, less is known about the role of microRNAs in urodele amphibian limb regeneration. Given the compelling evidence that many microRNAs tightly regulate cell fate and morphogenetic processes through development and adulthood by modulating the expression (or re-expression) of developmental genes, we investigated the possibility that microRNA levels change during limb regeneration. Using two different microarray platforms to compare the axolotl microRNA expression between mid-bud limb regenerating blastemas and non-regenerating stump tissues, we found that miR-21 was overexpressed in mid-bud blastemas compared to stump tissue. Mature A. mexicanum (“Amex”) miR-21 was detected in axolotl RNA by Northern blot and differential expression of Amex-miR-21 in blastema versus stump was confirmed by quantitative RT-PCR. We identified the Amex Jagged1 as a putative target gene for miR-21 during salamander limb regeneration. We cloned the full length 3′UTR of Amex-Jag1, and our in vitro assays demonstrated that its single miR-21 target recognition site is functional and essential for the response of the Jagged1 gene to miR-21 levels. Our findings pave the road for advanced in vivo functional assays aimed to clarify how microRNAs such as miR-21, often linked to pathogenic cell growth, might be modulating the redeployment of developmental genes such as Jagged1 during regenerative processes. PMID:23028429

Effect of Ankle Positioning During Hamstring Stretches for Improving Straight Leg Hip Flexion Motion.

PubMed

Laudner, Kevin G; Benjamin, Peter J; Selkow, Noelle M

2016-03-01

To compare the effects of stretching the hamstrings with the ankle in either a plantar-flexed (PF) or dorsiflexed (DF) position for improving straight leg hip flexion range of motion (ROM) over a 4-week period. Randomized, single-blinded, pretest, posttest design. Athletic training facility. Each limb of 34 asymptomatic individuals (15 males, 19 females) was randomly assigned to one of the 3 groups. Twenty-four limbs received hamstring stretches with the ankle in DF, 24 limbs received hamstring stretches with the ankle in PF, and 20 limbs received no stretch (control). Ankle position (PF, DF) during hamstring stretching. We measured pretest and posttest passive straight leg hip flexion ROM with the test ankle in a neutral position. For the intervention groups, the test limb was passively stretched with the ankle held in end range DF or PF for their respective group. Each stretch was held for 30 seconds for a total of 3 applications. Two treatment sessions were completed per week for a total of 4 weeks. The control limbs received no stretching during the 4-week period. We conducted 1-way analyses of covariance to determine significant changes in ROM between groups (P < 0.05). There was no significant difference between treatment groups (P = 0.90), but a significant difference was found for both the PF (P = 0.04) and DF (P = 0.01) groups when compared with the control group. Our findings indicate that both stretching the hamstrings in either PF or DF improve straight leg hip ROM compared with a control group. The results of this study should be considered by clinicians when determining the optimal stretching techniques aimed at increasing hamstring length.

Postnatal ontogeny of limb proportions and functional indices in the subterranean rodent Ctenomys talarum (Rodentia: Ctenomyidae).

PubMed

Echeverría, Alejandra Isabel; Becerra, Federico; Vassallo, Aldo Iván

2014-08-01

Burrow construction in the subterranean Ctenomys talarum (Rodentia: Ctenomyidae) primarily occurs by scratch-digging. In this study, we compared the limbs of an ontogenetic series of C. talarum to identify variation in bony elements related to fossorial habits using a morphometrical and biomechanical approach. Diameters and functional lengths of long bones were measured and 10 functional indices were constructed. We found that limb proportions of C. talarum undergo significant changes throughout postnatal ontogeny, and no significant differences between sexes were observed. Five of six forelimb indices and two of four hindlimb indices showed differences between ages. According to discriminant analysis, the indices that contributed most to discrimination among age groups were robustness of the humerus and ulna, relative epicondylar width, crural and brachial indices, and index of fossorial ability (IFA). Particularly, pups could be differentiated from juveniles and adults by more robust humeri and ulnae, wider epicondyles, longer middle limb elements, and a proportionally shorter olecranon. Greater robustness indicated a possible compensation for lower bone stiffness while wider epicondyles may be associated to improved effective forces in those muscles that originate onto them, compensating the lower muscular development. The gradual increase in the IFA suggested a gradual enhancement in the scratch-digging performance due to an improvement in the mechanical advantage of forearm extensors. Middle limb indices were higher in pups than in juveniles-adults, reflecting relatively more gracile limbs in their middle segments, which is in accordance with their incipient fossorial ability. In sum, our results show that in C. talarum some scratch-digging adaptations are already present during early postnatal ontogeny, which suggests that they are prenatally shaped, and other traits develop progressively. The role of early digging behavior as a factor influencing on morphology development is discussed. © 2014 Wiley Periodicals, Inc.

Outcomes of Peripheral Vascular Interventions in Select Patients With Lower Extremity Acute Limb Ischemia.

PubMed

Inagaki, Elica; Farber, Alik; Kalish, Jeffrey A; Eslami, Mohammad H; Siracuse, Jeffrey J; Eberhardt, Robert T; Rybin, Denis V; Doros, Gheorghe; Hamburg, Naomi M

2018-04-12

Contemporary data on patients presenting with acute limb ischemia (ALI), who are selected for treatment with endovascular peripheral vascular interventions (PVI), are limited. Our study examined outcomes following endovascular PVI in patients with ALI by comparing with patients treated for chronic critical limb ischemia using a regional quality improvement registry. Of the 11 035 patients in the Vascular Study Group of New England PVI database (2010-2014), we identified 365 patients treated for lower extremity ALI who were 5:1 frequency matched (by procedure year and arterial segments treated) to 1808 patients treated for critical limb ischemia. ALI patients treated with PVI had high burden of atherosclerotic risk factors and were more likely to have had prior ipsilateral revascularizations. ALI patients were less likely to be treated with self-expanding stents and more likely to undergo thrombolysis than patients with critical limb ischemia. In multivariable analysis, ALI was associated with higher technical failure (odds ratio 1.7, 95% confidence interval, 1.1%-2.5%), increased rate of distal embolization (odds ratio 2.7, 95% confidence interval, 1.5%-4.9%), longer length of stay (means ratio 1.6, 95% confidence interval, 1.4%-1.8%), and higher in-hospital mortality (odds ratio 2.8, 95% confidence interval, 1.3%-5.9%). ALI was not associated with risk of major amputation or mortality at 1 year. In a multicenter cohort of patients treated with PVI, we found that ALI patients selected for treatment with endovascular techniques experienced greater short-term adverse events but similar long-term outcomes as their critical limb ischemia counterparts. Further studies are needed to refine the selection of ALI patients who are best served by PVI. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

The role of the extrinsic thoracic limb muscles in equine locomotion.

PubMed

Payne, R C; Veenman, P; Wilson, A M

2005-02-01

Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cross-sectional area and maximum isometric force were then estimated. Maximum power was estimated from muscle volume and published contraction velocity data. The majority of extrinsic forelimb muscles were large with long fascicles arranged in parallel to the long axis of the muscle. Muscles arranged in this way are optimised for doing work. The architecture of serratus ventralis thoracis (SVT) was unique. It had short (48 +/- 17 mm) fascicles, arranged at about 45 degrees to the long axis of the muscle, which would suggest a force-generating, anti-gravity role. The muscle belly of SVT was sandwiched between two broad, thick sheets of aponeurosis. Hence, SVT could make a significant contribution to the overall elastic properties of the thoracic limb.

The role of the extrinsic thoracic limb muscles in equine locomotion.

PubMed

Payne, R C; Veenman, P; Wilson, A M

2004-12-01

Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cross-sectional area and maximum isometric force were then estimated. Maximum power was estimated from muscle volume and published contraction velocity data. The majority of extrinsic forelimb muscles were large with long fascicles arranged in parallel to the long axis of the muscle. Muscles arranged in this way are optimised for doing work. The architecture of serratus ventralis thoracis (SVT) was unique. It had short (48 +/- 17 mm) fascicles, arranged at about 45 degrees to the long axis of the muscle, which would suggest a force-generating, anti-gravity role. The muscle belly of SVT was sandwiched between two broad, thick sheets of aponeurosis. Hence, SVT could make a significant contribution to the overall elastic properties of the thoracic limb.

Upper limb stroke rehabilitation: the effectiveness of Stimulation Assistance through Iterative Learning (SAIL).

PubMed

Meadmore, Katie L; Cai, Zhonglun; Tong, Daisy; Hughes, Ann-Marie; Freeman, Chris T; Rogers, Eric; Burridge, Jane H

2011-01-01

A novel system has been developed which combines robotic therapy with electrical stimulation (ES) for upper limb stroke rehabilitation. This technology, termed SAIL: Stimulation Assistance through Iterative Learning, employs advanced model-based iterative learning control (ILC) algorithms to precisely assist participant's completion of 3D tracking tasks with their impaired arm. Data is reported from a preliminary study with unimpaired participants, and also from a single hemiparetic stroke participant with reduced upper limb function who has used the system in a clinical trial. All participants completed tasks which involved moving their (impaired) arm to follow an image of a slowing moving sphere along a trajectory. The participants' arm was supported by a robot and ES was applied to the triceps brachii and anterior deltoid muscles. During each task, the same tracking trajectory was repeated 6 times and ILC was used to compute the stimulation signals to be applied on the next iteration. Unimpaired participants took part in a single, one hour training session and the stroke participant undertook 18, 1 hour treatment sessions composed of tracking tasks varying in length, orientation and speed. The results reported describe changes in tracking ability and demonstrate feasibility of the SAIL system for upper limb rehabilitation. © 2011 IEEE

Alternate pathways of body shape evolution translate into common patterns of locomotor evolution in two clades of lizards.

PubMed

Bergmann, Philip J; Irschick, Duncan J

2010-06-01

Body shape has a fundamental impact on organismal function, but it is unknown how functional morphology and locomotor performance and kinematics relate across a diverse array of body shapes. We showed that although patterns of body shape evolution differed considerably between lizards of the Phrynosomatinae and Lerista, patterns of locomotor evolution coincided between clades. Specifically, we found that the phrynosomatines evolved a stocky phenotype through body widening and limb shortening, whereas Lerista evolved elongation through body lengthening and limb shortening. In both clades, relative limb length played a key role in locomotor evolution and kinematic strategies, with long-limbed species moving faster and taking longer strides. In Lerista, the body axis also influenced locomotor evolution. Similar patterns of locomotor evolution were likely due to constraints on how the body can move. However, these common patterns of locomotor evolution between the two clades resulted in different kinematic strategies and levels of performance among species because of their morphological differences. Furthermore, we found no evidence that distinct body shapes are adaptations to different substrates, as locomotor kinematics did not change on loose or solid substrates. Our findings illustrate the importance of studying kinematics to understand the mechanisms of locomotor evolution and phenotype-function relationships.

The role of the extrinsic thoracic limb muscles in equine locomotion

PubMed Central

Payne, RC; Veenman, P; Wilson, AM

2005-01-01

Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cross-sectional area and maximum isometric force were then estimated. Maximum power was estimated from muscle volume and published contraction velocity data. The majority of extrinsic forelimb muscles were large with long fascicles arranged in parallel to the long axis of the muscle. Muscles arranged in this way are optimised for doing work. The architecture of serratus ventralis thoracis (SVT) was unique. It had short (48 ± 17 mm) fascicles, arranged at about 45° to the long axis of the muscle, which would suggest a force-generating, anti-gravity role. The muscle belly of SVT was sandwiched between two broad, thick sheets of aponeurosis. Hence, SVT could make a significant contribution to the overall elastic properties of the thoracic limb. PMID:15730484

The role of the extrinsic thoracic limb muscles in equine locomotion

PubMed Central

Payne, R C; Veenman, P; Wilson, A M

2004-01-01

Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cross-sectional area and maximum isometric force were then estimated. Maximum power was estimated from muscle volume and published contraction velocity data. The majority of extrinsic forelimb muscles were large with long fascicles arranged in parallel to the long axis of the muscle. Muscles arranged in this way are optimised for doing work. The architecture of serratus ventralis thoracis (SVT) was unique. It had short (48 ± 17 mm) fascicles, arranged at about 45° to the long axis of the muscle, which would suggest a force-generating, anti-gravity role. The muscle belly of SVT was sandwiched between two broad, thick sheets of aponeurosis. Hence, SVT could make a significant contribution to the overall elastic properties of the thoracic limb. PMID:15610395

Effects of unilateral selective hypergravity stimulation on gait

NASA Astrophysics Data System (ADS)

Lazerges, M.; Bessou, P.

The purpose of this work is to analyse the neural mechanisms of human motor perturbations induced by dynamic changes in gravity. A unilateral selective hypergravity stimulation (USHS) was produced by stretching an elastic band between the right shoulder and foot. The consequences of the extensor muscle tone change due to the positioning (increased muscular loading) and to its removal (decreased muscular loading) by the elastic band were observed on motor gait skill. Gait spatio-temporal parameters (horizontal displacement of both feet) and lower limb functional length variations (efficiency of flexion and extension movements of the lower limbs) were measured. The latter measure was performed using a device specially designed for that purpose. The main results were: (1) during and after USHS, gait perturbations appeared on the left—the body side not directly stimulated, (2) just after the end of USHS, perturbations were present on the right (homolateral) side evidencing a post treatment effect which caused a decrease in functional shortening of the lower limb during extension and an increase of functional shortening of the lower limb during stance (opposite in sense to the modification observed during swing). Such results afford evidence that, in addition to vestibular receptors, the mechanoreceptors of extensor muscles are involved in determining the changes in motor skills observed at the beginning and at the end of space flights.

Comparison of submuscular and open plating of pediatric femur fractures: a retrospective review.

PubMed

Abbott, Matthew D; Loder, Randall T; Anglen, Jeffrey O

2013-01-01

Plate osteosynthesis is an accepted method of treatment of pediatric femur fractures. Historically, open plating has been used. Submuscular bridge plating has gained recent popularity due to the theoretical advantages of decreased operative time, decreased blood loss, and decreased risk for infection. The purpose of this study was to compare submuscular bridge plating to open plating of pediatric femur fractures. We retrospectively reviewed 79 patients (80 treated femur fractures) between 1999 and 2011 that underwent either open plating (58 femur fractures) or submuscular bridge plating (22 femur fractures). The outcome measures evaluated were operative time, estimated blood loss, malunion, leg length discrepancy, time to union, infection, unplanned return to the operating room, and length of hospital stay after surgery. Among our outcome measures, there was no difference between the 2 groups in terms of operative time, leg length discrepancy, time to union, infection, or length of hospital stay after surgery. There was greater estimated blood loss in the open plating group (P≤0.0001) and greater rotational asymmetry in the submuscular bridge plating group (P=0.005). There was a trend of increased unplanned return to the operating room in the open plating group (5/58 vs. 0/22) although not statistically significant (P=0.32). Submuscular bridge plating and open plating seem to be equally viable options for the management of pediatric diaphyseal femur fractures. In this study, open plating had an increase in estimated blood loss and a trend of more unplanned returns to the operating room, whereas submuscular bridge plating had an increase in asymptomatic rotational asymmetry. Further larger, prospective, randomized studies are necessary to further evaluate these operative techniques. Therapeutic Level III.

Influence of Sub-Daily Variation on Multi-Fractal Detrended Fluctuation Analysis of Wind Speed Time Series

PubMed Central

Li, Weinan; Kong, Yanjun; Cong, Xiangyu

2016-01-01

Using multi-fractal detrended fluctuation analysis (MF-DFA), the scaling features of wind speed time series (WSTS) could be explored. In this paper, we discuss the influence of sub-daily variation, which is a natural feature of wind, in MF-DFA of WSTS. First, the choice of the lower bound of the segment length, a significant parameter of MF-DFA, was studied. The results of expanding the lower bound into sub-daily scope shows that an abrupt declination and discrepancy of scaling exponents is caused by the inability to keep the whole diel process of wind in one single segment. Additionally, the specific value, which is effected by the sub-daily feature of local meteo-climatic, might be different. Second, the intra-day temporal order of wind was shuffled to determine the impact of diel variation on scaling exponents of MF-DFA. The results illustrate that disregarding diel variation leads to errors in scaling. We propose that during the MF-DFA of WSTS, the segment length should be longer than 1 day and the diel variation of wind should be maintained to avoid abnormal phenomena and discrepancy in scaling exponents. PMID:26741491

Geographic variation in body form of prehistoric Jomon males in the Japanese archipelago: its ecogeographic implications.

PubMed

Fukase, Hitoshi; Wakebe, Tetsuaki; Tsurumoto, Toshiyuki; Saiki, Kazunobu; Fujita, Masaki; Ishida, Hajime

2012-09-01

Diversity of human body size and shape is often biogeographically interpreted in association with climatic conditions. According to Bergmann's and Allen's rules, populations in regions with a cold climate are expected to display an overall larger body and smaller/shorter extremities than those in warm/hot environments. In the present study, the skeletal limb size and proportions of prehistoric Jomon hunter-gatherers, who extensively inhabited subarctic to subtropical areas in the ancient Japanese archipelago, were examined to evaluate whether or not the inter-regional differences follow such ecogeographic patterns. Results showed that the Jomon intralimb proportions including relative distal limb lengths did not differ significantly among five regions from northern Hokkaido to the southern Okinawa Islands. This suggests a limited co-variability of the intralimb proportions with climate, particularly within genealogically close populations. In contrast, femoral head breadth (associated with body mass) and skeletal limb lengths were found to be significantly and positively correlated with latitude, suggesting a north-south geographical cline in the body size. This gradient therefore comprehensively conforms to Bergmann's rule, and may stem from multiple potential factors such as phylogenetic constraints, microevolutionary adaptation to climatic/geographic conditions during the Jomon period, and nutritional and physiological response during ontogeny. Specifically, the remarkably small-bodied Jomon in the Okinawa Islands can also be explained as an adjustment to subtropical and insular environments. Thus, the findings obtained in this study indicate that Jomon people, while maintaining fundamental intralimb proportions, displayed body size variation in concert with ambient surroundings. Copyright © 2012 Wiley Periodicals, Inc.

Scaling of avian bipedal locomotion reveals independent effects of body mass and leg posture on gait.

PubMed

Daley, Monica A; Birn-Jeffery, Aleksandra

2018-05-22

Birds provide an interesting opportunity to study the relationships between body size, limb morphology and bipedal locomotor function. Birds are ecologically diverse and span a large range of body size and limb proportions, yet all use their hindlimbs for bipedal terrestrial locomotion, for at least some part of their life history. Here, we review the scaling of avian striding bipedal gaits to explore how body mass and leg morphology influence walking and running. We collate literature data from 21 species, spanning a 2500× range in body mass from painted quail to ostriches. Using dynamic similarity theory to interpret scaling trends, we find evidence for independent effects of body mass, leg length and leg posture on gait. We find no evidence for scaling of duty factor with body size, suggesting that vertical forces scale with dynamic similarity. However, at dynamically similar speeds, large birds use relatively shorter stride lengths and higher stride frequencies compared with small birds. We also find that birds with long legs for their mass, such as the white stork and red-legged seriema, use longer strides and lower swing frequencies, consistent with the influence of high limb inertia on gait. We discuss the observed scaling of avian bipedal gait in relation to mechanical demands for force, work and power relative to muscle actuator capacity, muscle activation costs related to leg cycling frequency, and considerations of stability and agility. Many opportunities remain for future work to investigate how morphology influences gait dynamics among birds specialized for different habitats and locomotor behaviors. © 2018. Published by The Company of Biologists Ltd.

A test of the universal applicability of a commonly used principle of hoof balance.

PubMed

Caldwell, M N; Allan, L A; Pinchbeck, G L; Clegg, P D; Kissick, K E; Milner, P I

2016-01-01

This study used a UK trimming protocol to determine whether hoof balance is achieved (as defined by equivalence of geometric proportions) in cadaver limbs (n = 49) and two cohorts of horses (shod, n = 6, and unshod, n = 20; three trimming cycles). To determine equivalence, dorsal hoof wall length (DHWL), distance from the heel buttress to the centre of pressure (HBUT-COP) and distance from dorsal toe to centre of rotation (DT-COR) were calculated as a proportion of bearing border length (BBL) using digital photography. Geometric proportions were tested using Fieller's test of equivalence with limits of difference of 2.8%. In 22 cadaver limbs the location of external COR and COP was also mapped radiographically to the extensor process of the third phalanx and the centre of rotation of the distal interphalangeal joint. Equivalence of geometric proportions was not present following trimming in cadaver limbs or in the two cohorts. Although the dorsal hoof wall to heel wall ratio improved in cadaver and unshod horses after trimming, dorsal hoof wall and lateral heel parallelism was absent in all groups and COP was not consistently in line with the extensor process. Increased COP-COR distance occurred in shod horses and may relate to solar arch flattening. Palmar heel migration, however, occurred more in unshod horses. The study shows that equivalence of geometric proportions as a measure of static hoof balance was not commonly present and widely published measures and ratios of hoof balance rarely occurred in this sample population of horses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evolution of morphology and locomotor performance in anurans: relationships with microhabitat diversification.

PubMed

Citadini, J M; Brandt, R; Williams, C R; Gomes, F R

2018-03-01

The relationships between morphology, performance, behavior and ecology provide evidence for multiple and complex phenotypic adaptations. The anuran body plan, for example, is evolutionarily conserved and shows clear specializations to jumping performance back at least to the early Jurassic. However, there are instances of more recent adaptation to habit diversity in the post-cranial skeleton, including relative limb length. The present study tested adaptive models of morphological evolution in anurans associated with the diversity of microhabitat use (semi-aquatic arboreal, fossorial, torrent, and terrestrial) in species of anuran amphibians from Brazil and Australia. We use phylogenetic comparative methods to determine which evolutionary models, including Brownian motion (BM) and Ornstein-Uhlenbeck (OU) are consistent with morphological variation observed across anuran species. Furthermore, this study investigated the relationship of maximum distance jumped as a function of components of morphological variables and microhabitat use. We found there are multiple optima of limb lengths associated to different microhabitats with a trend of increasing hindlimbs in torrent, arboreal, semi-aquatic whereas fossorial and terrestrial species evolve toward optima with shorter hindlimbs. Moreover, arboreal, semi-aquatic and torrent anurans have higher jumping performance and longer hindlimbs, when compared to terrestrial and fossorial species. We corroborate the hypothesis that evolutionary modifications of overall limb morphology have been important in the diversification of locomotor performance along the anuran phylogeny. Such evolutionary changes converged in different phylogenetic groups adapted to similar microhabitat use in two different zoogeographical regions. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Efficacy and safety of rivaroxaban versus low-molecular-weight heparin therapy in patients with lower limb fractures.

PubMed

Long, Anhua; Zhang, Lihai; Zhang, Yingze; Jiang, Baoguo; Mao, Zhi; Li, Hongda; Zhang, Shanbao; Xie, Zongyan; Tang, Peifu

2014-10-01

Thromboprophylaxis with rivaroxaban has proved effective and safe in patients undergoing hip and knee replacement surgery. As it is unclear whether it is also effective and safe in fracture patients, the aim of the present study was to evaluate the efficacy and safety of rivaroxaban in patients with lower limb fractures. We performed a retrospective cohort study of 2,050 consecutive patients treated for lower limb fractures at our trauma center, comparing rates of venous thromboembolism (VTE), bleeding and surgical complications, and the length of hospital stay for 608 patients who received rivaroxaban and 717 who received a low-molecular-weight heparin (LMWH). Rates of symptomatic VTE were 4.9 and 8.6% in the rivaroxaban and LMWH groups, respectively (p = 0.008), and distal VTE rates were 1.8 and 5.7%, respectively (p = 0.036). The incidence of major bleeding events in the rivaroxaban group was also lower than in the LMWH group (0.2 vs 0.6%), but the difference between the groups was not statistically significant. The mean length of hospital stay was significantly shorter in the rivaroxaban group (12.2 vs 13.1 days, respectively; p = 0.016). This retrospective cohort study is the first report documenting the efficacy and safety of rivaroxaban in patients with lower extremity fractures. In comparison with LMWH, rivaroxaban reduced the incidence of VTE by 45% without increasing the risk of bleeding. However, prospective, randomized controlled trials comparing rivaroxaban and LMWH are needed to confirm our findings.

Cellular and Morphological Alterations in the Vastus Lateralis Muscle as the Result of ACL Injury and Reconstruction.

PubMed

Noehren, Brian; Andersen, Anders; Hardy, Peter; Johnson, Darren L; Ireland, Mary Lloyd; Thompson, Katherine L; Damon, Bruce

2016-09-21

Individuals who have had an anterior cruciate ligament (ACL) tear and reconstruction continue to experience substantial knee extensor strength loss despite months of physical therapy. Identification of the alterations in muscle morphology and cellular composition are needed to understand potential mechanisms of muscle strength loss, initially as the result of the injury and subsequently from surgery and rehabilitation. We performed diffusion tensor imaging-magnetic resonance imaging and analyzed muscle biopsies from the vastus lateralis of both the affected and unaffected limbs before surgery and again from the reconstructed limb following the completion of rehabilitation. Immunohistochemistry was done to determine fiber type and size, Pax-7-positive (satellite) cells, and extracellular matrix (via wheat germ agglutinin straining). Using the diffusion tensor imaging data, the fiber tract length, pennation angle, and muscle volume were determined, yielding the physiological cross-sectional area (PCSA). Paired t tests were used to compare the effects of the injury between injured and uninjured limbs and the effects of surgery and rehabilitation within the injured limb. We found significant reductions before surgery in type-IIA muscle cross-sectional area (CSA; p = 0.03), extracellular matrix (p < 0.01), satellite cells per fiber (p < 0.01), pennation angle (p = 0.03), muscle volume (p = 0.02), and PCSA (p = 0.03) in the injured limb compared with the uninjured limb. Following surgery, these alterations in the injured limb persisted and the frequency of the IIA fiber type decreased significantly (p < 0.01) and that of the IIA/X hybrid fiber type increased significantly (p < 0.01). Significant and prolonged differences in muscle quality and morphology occurred after ACL injury and persisted despite reconstruction and extensive physical therapy. These results suggest the need to develop more effective early interventions following an ACL tear to prevent deleterious alterations within the quadriceps. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Post-amputation pain is associated with the recall of an impaired body representation in dreams-results from a nation-wide survey on limb amputees.

PubMed

Bekrater-Bodmann, Robin; Schredl, Michael; Diers, Martin; Reinhard, Iris; Foell, Jens; Trojan, Jörg; Fuchs, Xaver; Flor, Herta

2015-01-01

The experience of post-amputation pain such as phantom limb pain (PLP) and residual limb pain (RLP), is a common consequence of limb amputation, and its presence has negative effects on a person's well-being. The continuity hypothesis of dreams suggests that the presence of such aversive experiences in the waking state should be reflected in dream content, with the recalled body representation reflecting a cognitive proxy of negative impact. In the present study, we epidemiologically assessed the presence of post-amputation pain and other amputation-related information as well as recalled body representation in dreams in a sample of 3,234 unilateral limb amputees. Data on the site and time of amputation, residual limb length, prosthesis use, lifetime prevalence of mental disorders, presence of post-amputation pain, and presence of non-painful phantom phenomena were included in logistic regression analyses using recalled body representation in dreams (impaired, intact, no memory) as dependent variable. The effects of age, sex, and frequency of dream recall were controlled for. About 22% of the subjects indicated that they were not able to remember their body representation in dreams, another 24% of the amputees recalled themselves as always intact, and only a minority of less than 3% recalled themselves as always impaired. Almost 35% of the amputees dreamed of themselves in a mixed fashion. We found that lower-limb amputation as well as the presence of PLP and RLP was positively associated with the recall of an impaired body representation in dreams. The presence of non-painful phantom phenomena, however, had no influence. These results complement previous findings and indicate complex interactions of physical body appearance and mental body representation, probably modulated by distress in the waking state. The findings are discussed against the background of alterations in cognitive processes after amputation and hypotheses suggesting an innate body model.

Post-Amputation Pain Is Associated with the Recall of an Impaired Body Representation in Dreams—Results from a Nation-Wide Survey on Limb Amputees

PubMed Central

Bekrater-Bodmann, Robin; Schredl, Michael; Diers, Martin; Reinhard, Iris; Foell, Jens; Trojan, Jörg; Fuchs, Xaver; Flor, Herta

2015-01-01

The experience of post-amputation pain such as phantom limb pain (PLP) and residual limb pain (RLP), is a common consequence of limb amputation, and its presence has negative effects on a person’s well-being. The continuity hypothesis of dreams suggests that the presence of such aversive experiences in the waking state should be reflected in dream content, with the recalled body representation reflecting a cognitive proxy of negative impact. In the present study, we epidemiologically assessed the presence of post-amputation pain and other amputation-related information as well as recalled body representation in dreams in a sample of 3,234 unilateral limb amputees. Data on the site and time of amputation, residual limb length, prosthesis use, lifetime prevalence of mental disorders, presence of post-amputation pain, and presence of non-painful phantom phenomena were included in logistic regression analyses using recalled body representation in dreams (impaired, intact, no memory) as dependent variable. The effects of age, sex, and frequency of dream recall were controlled for. About 22% of the subjects indicated that they were not able to remember their body representation in dreams, another 24% of the amputees recalled themselves as always intact, and only a minority of less than 3% recalled themselves as always impaired. Almost 35% of the amputees dreamed of themselves in a mixed fashion. We found that lower-limb amputation as well as the presence of PLP and RLP was positively associated with the recall of an impaired body representation in dreams. The presence of non-painful phantom phenomena, however, had no influence. These results complement previous findings and indicate complex interactions of physical body appearance and mental body representation, probably modulated by distress in the waking state. The findings are discussed against the background of alterations in cognitive processes after amputation and hypotheses suggesting an innate body model. PMID:25742626

A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods.

PubMed

Campione, Nicolás E; Evans, David C

2012-07-10

Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial quadrupeds, which is important for a wide range of paleobiological studies (including growth rates, metabolism, and energetics) and meta-analyses of body size evolution.

A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods

PubMed Central

2012-01-01

Background Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. Results Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. Conclusions The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial quadrupeds, which is important for a wide range of paleobiological studies (including growth rates, metabolism, and energetics) and meta-analyses of body size evolution. PMID:22781121

The length-force behavior and operating length range of squid muscle vary as a function of position in the mantle wall.

PubMed

Thompson, Joseph T; Shelton, Ryan M; Kier, William M

2014-06-15

Hollow cylindrical muscular organs are widespread in animals and are effective in providing support for locomotion and movement, yet are subject to significant non-uniformities in circumferential muscle strain. During contraction of the mantle of squid, the circular muscle fibers along the inner (lumen) surface of the mantle experience circumferential strains 1.3 to 1.6 times greater than fibers along the outer surface of the mantle. This transmural gradient of strain may require the circular muscle fibers near the inner and outer surfaces of the mantle to operate in different regions of the length-tension curve during a given mantle contraction cycle. We tested the hypothesis that circular muscle contractile properties vary transmurally in the mantle of the Atlantic longfin squid, Doryteuthis pealeii. We found that both the length-twitch force and length-tetanic force relationships of the obliquely striated, central mitochondria-poor (CMP) circular muscle fibers varied with radial position in the mantle wall. CMP circular fibers near the inner surface of the mantle produced higher force relative to maximum isometric tetanic force, P0, at all points along the ascending limb of the length-tension curve than CMP circular fibers near the outer surface of the mantle. The mean ± s.d. maximum isometric tetanic stresses at L₀ (the preparation length that produced the maximum isometric tetanic force) of 212 ± 105 and 290 ± 166 kN m(-2) for the fibers from the outer and inner surfaces of the mantle, respectively, did not differ significantly (P=0.29). The mean twitch:tetanus ratios for the outer and inner preparations, 0.60 ± 0.085 and 0.58 ± 0.10, respectively, did not differ significantly (P=0.67). The circular fibers did not exhibit length-dependent changes in contraction kinetics when given a twitch stimulus. As the stimulation frequency increased, L₀ was approximately 1.06 times longer than LTW, the mean preparation length that yielded maximum isometric twitch force. Sonomicrometry experiments revealed that the CMP circular muscle fibers operated in vivo primarily along the ascending limb of the length-tension curve. The CMP fibers functioned routinely over muscle lengths at which force output ranged from only 85% to 40% of P₀, and during escape jets from 100% to 30% of P₀. Our work shows that the functional diversity of obliquely striated muscles is much greater than previously recognized. © 2014. Published by The Company of Biologists Ltd.

Widespread differential maternal and paternal genome effects on fetal bone phenotype at mid-gestation.

PubMed

Xiang, Ruidong; Lee, Alice M C; Eindorf, Tanja; Javadmanesh, Ali; Ghanipoor-Samami, Mani; Gugger, Madeleine; Fitzsimmons, Carolyn J; Kruk, Zbigniew A; Pitchford, Wayne S; Leviton, Alison J; Thomsen, Dana A; Beckman, Ian; Anderson, Gail I; Burns, Brian M; Rutley, David L; Xian, Cory J; Hiendleder, Stefan

2014-11-01

Parent-of-origin-dependent (epi)genetic factors are important determinants of prenatal development that program adult phenotype. However, data on magnitude and specificity of maternal and paternal genome effects on fetal bone are lacking. We used an outbred bovine model to dissect and quantify effects of parental genomes, fetal sex, and nongenetic maternal effects on the fetal skeleton and analyzed phenotypic and molecular relationships between fetal muscle and bone. Analysis of 51 bone morphometric and weight parameters from 72 fetuses recovered at day 153 gestation (54% term) identified six principal components (PC1-6) that explained 80% of the variation in skeletal parameters. Parental genomes accounted for most of the variation in bone wet weight (PC1, 72.1%), limb ossification (PC2, 99.8%), flat bone size (PC4, 99.7%), and axial skeletal growth (PC5, 96.9%). Limb length showed lesser effects of parental genomes (PC3, 40.8%) and a significant nongenetic maternal effect (gestational weight gain, 29%). Fetal sex affected bone wet weight (PC1, p < 0.0001) and limb length (PC3, p < 0.05). Partitioning of variation explained by parental genomes revealed strong maternal genome effects on bone wet weight (74.1%, p < 0.0001) and axial skeletal growth (93.5%, p < 0.001), whereas paternal genome controlled limb ossification (95.1%, p < 0.0001). Histomorphometric data revealed strong maternal genome effects on growth plate height (98.6%, p < 0.0001) and trabecular thickness (85.5%, p < 0.0001) in distal femur. Parental genome effects on fetal bone were mirrored by maternal genome effects on fetal serum 25-hydroxyvitamin D (96.9%, p < 0.001) and paternal genome effects on alkaline phosphatase (90.0%, p < 0.001) and their correlations with maternally controlled bone wet weight and paternally controlled limb ossification, respectively. Bone wet weight and flat bone size correlated positively with muscle weight (r = 0.84 and 0.77, p < 0.0001) and negatively with muscle H19 expression (r = -0.34 and -0.31, p < 0.01). Because imprinted maternally expressed H19 regulates growth factors by miRNA interference, this suggests muscle-bone interaction via epigenetic factors. © 2014 American Society for Bone and Mineral Research.

Improvement in gait following combined ankle and subtalar arthrodesis.

PubMed

Tenenbaum, Shay; Coleman, Scott C; Brodsky, James W

2014-11-19

This study assessed the hypothesis that arthrodesis of both the ankle and the hindfoot joints produces an objective improvement of function as measured by gait analysis of patients with severe ankle and hindfoot arthritis. Twenty-one patients with severe ankle and hindfoot arthritis who underwent unilateral tibiotalocalcaneal arthrodesis with an intramedullary nail were prospectively studied with three-dimensional (3D) gait analysis at a minimum of one year postoperatively. The mean age at the time of the operation was fifty-nine years, and the mean duration of follow-up was seventeen months (range, twelve to thirty-one months). Temporospatial measurements included cadence, step length, walking velocity, and total support time. The kinematic parameters were sagittal plane motion of the ankle, knee, and hip. The kinetic parameters were sagittal plane ankle power and moment and hip power. Symmetry of gait was analyzed by comparing the step lengths on the affected and unaffected sides. There was significant improvement in multiple parameters of postoperative gait as compared with the patients' own preoperative function. Temporospatial data showed significant increases in cadence (p = 0.03) and walking speed (p = 0.001) and decreased total support time (p = 0.02). Kinematic results showed that sagittal plane ankle motion had decreased, from 13.2° preoperatively to 10.2° postoperatively, in the operatively treated limb (p = 0.02), and increased from 22.2° to 24.1° (p = 0.01) in the contralateral limb. Hip motion on the affected side increased from 39° to 43° (p = 0.007), and knee motion increased from 56° to 60° (p = 0.054). Kinetic results showed significant increases in ankle moment (p < 0.0001) of the operatively treated limb, ankle power of the contralateral limb (p = 0.009), and hip power on the affected side (p = 0.005) postoperatively. There was a significant improvement in gait symmetry (p = 0.01). There was a small loss of sagittal plane motion in the affected limb postoperatively. There were marked increases in gait velocity, ankle moment, and hip motion and power, documenting objective improvements in ambulatory function. The data showed that preoperative ankle motion was greatly diminished. This may suggest that pain is more important than stiffness in asymmetric gait. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Correlation lengths in hydrodynamic models of active nematics.

PubMed

Hemingway, Ewan J; Mishra, Prashant; Marchetti, M Cristina; Fielding, Suzanne M

2016-09-28

We examine the scaling with activity of the emergent length scales that control the nonequilibrium dynamics of an active nematic liquid crystal, using two popular hydrodynamic models that have been employed in previous studies. In both models we find that the chaotic spatio-temporal dynamics in the regime of fully developed active turbulence is controlled by a single active scale determined by the balance of active and elastic stresses, regardless of whether the active stress is extensile or contractile in nature. The observed scaling of the kinetic energy and enstrophy with activity is consistent with our single-length scale argument and simple dimensional analysis. Our results provide a unified understanding of apparent discrepancies in the previous literature and demonstrate that the essential physics is robust to the choice of model.

Mesomelic dwarfism in pseudoachondroplasia.

PubMed

Song, Hae-Ryong; Li, Qi-Wei; Oh, Chang-Wug; Lee, Kwang-Soo; Koo, Soo Kyung; Jung, Sung-Chul

2004-09-01

Pseudoachondroplasia (PSACH) is associated with mutations in the cartilage oligomeric matrix protein (COMP) gene and the clinical characteristics include short stature, deformities of the extremities involving the epiphyses and metaphyses, early onset arthritis, and ligament laxity. PSACH has been considered a rhizomelic form of dwarfism. So far no previous report has described mesomelic shortening of the limbs in PSACH. We reviewed nine patients with a diagnosis of PSACH based on clinical and radiographic examination and mutation analysis of the COMP gene. The mean height in the adults was 116 cm. All patients showed mesomelic dwarfism. The average ratios of radial length to humeral length and tibial length to femoral length were 0.62 and 0.63, respectively. The tibia and the radius showed more severe bony deformity than the femur and humerus. The degree of short stature was related to the site of the mutation in the COMP gene, but there was no correlation between bony deformity and height or gene mutation.

An evaluation of water vapor radiometer data for calibration of the wet path delay in very long baseline interferometry experiments

NASA Technical Reports Server (NTRS)

Kuehn, C. E.; Himwich, W. E.; Clark, T. A.; Ma, C.

1991-01-01

The internal consistency of the baseline-length measurements derived from analysis of several independent VLBI experiments is an estimate of the measurement precision. The paper investigates whether the inclusion of water vapor radiometer (WVR) data as an absolute calibration of the propagation delay due to water vapor improves the precision of VLBI baseline-length measurements. The paper analyzes 28 International Radio Interferometric Surveying runs between June 1988 and January 1989; WVR measurements were made during each session. The addition of WVR data decreased the scatter of the length measurements of the baselines by 5-10 percent. The observed reduction in the scatter of the baseline lengths is less than what is expected from the behavior of the formal errors, which suggest that the baseline-length measurement precision should improve 10-20 percent if WVR data are included in the analysis. The discrepancy between the formal errors and the baseline-length results can be explained as the consequence of systematic errors in the dry-mapping function parameters, instrumental biases in the WVR and the barometer, or both.

Mapping Active Stream Lengths as a Tool for Understanding Spatial Variations in Runoff Generation

NASA Astrophysics Data System (ADS)

Erwin, E. G.; Gannon, J. P.; Zimmer, M. A.

2016-12-01

Recent studies have shown temporary stream channels respond in complex ways to precipitation. By investigating how stream networks expand and recede throughout rain events, we may further develop our understanding of runoff generation. This study focused on mapping the expansion and contraction of the stream network in two headwater catchments characterized by differing soil depths and slopes, located in North Carolina, USA. The first is a 43 ha catchment located in the Southern Appalachian region, characterized by incised, steep slopes and soils of varying thickness. The second is a 3.3 ha catchment located in the Piedmont region, characterized as low relief with deep, highly weathered soils. Over a variety of flow conditions, surveys of the entire stream network were conducted at 10 m intervals to determine presence or absence of surface water. These surveys revealed several reaches within the networks that were intermittent, with perennial flow upstream and downstream. Furthermore, in some tributaries, the active stream head moved up the channel in response to precipitation and at others it remained anchored in place. Moreover, when repeat surveys were performed during the same storm, hysteresis was observed in active stream length variations: stream length was not the same on the rising limb and falling limb of the hydrograph. These observations suggest there are different geomorphological controls or runoff generation processes occurring spatially throughout these catchments. Observations of wide spatial and temporal variability of active stream length over a variety of flow conditions suggest runoff dynamics, generation mechanisms, and contributing flowpath depths producing streamflow may be highly variable and not easily predicted from streamflow observations at a fixed point. Finally, the observation of similar patterns in differing geomorphic regions suggests these processes extend beyond unique site characterizations.

Directional Asymmetry in the Limbs, Skull and Pelvis of the Silver Fox (V. vulpes)

PubMed Central

Kharlamova, Anastasia V.; Trut, Lyudmila N.; Chase, Kevin; Kukekova, Anna V.; Lark, Karl G.

2011-01-01

Directional asymmetry (DA) is a characteristic of most vertebrates, most strikingly exhibited by the placement of various organs (heart, lungs, liver, etc.) but also noted in small differences in the metrics of skeletal structures such as the pelvis of certain fish or sauropsids. We have analyzed DA in the skeleton of the fox (V. vulpes), using ~1,000 radiographs of foxes from populations used in the genetic analysis of behavior and morphology. Careful measurements from this robust data base demonstrate that: 1) DA occurs in the limb bones, the ileum, and ischium and in the mandible; 2) regardless of the direction of the length asymmetry vector of a particular skeletal unit, the vectorial direction of length is always opposite to that of width; 3) with the exception of the humerus and radius, there is no correlation or inverse correlation between vectorial amplitudes or magnitudes of bone asymmetries. 4) Postnatal measurements on foxes demonstrate that the asymmetry increases after birth and continues to change (increasing or decreasing) during postnatal growth. 5) A behavior test for preferential use of a specific forelimb exhibited fluctuating asymmetry but not DA. None of the skeletal asymmetries were significantly correlated with a preferential use of a specific forelimb. We suggest that for the majority of fox skeletal parameters, growth on the right and left side of the fox are differentially biased resulting in fixed differences between the two sides in either the rate of growth or the length of the period during which growth occurs. Random effects around these fixed differences perturb the magnitude of the effects such that the magnitudes of length and width asymmetries are not inversely correlated at the level of individual animals. PMID:20862692

Directional asymmetry in the limbs, skull and pelvis of the silver fox (V. vulpes).

PubMed

Kharlamova, Anastasia V; Trut, Lyudmila N; Chase, Kevin; Kukekova, Anna V; Lark, Karl G

2010-12-01

Directional asymmetry (DA) is a characteristic of most vertebrates, most strikingly exhibited by the placement of various organs (heart, lungs, liver, etc.) but also noted in small differences in the metrics of skeletal structures such as the pelvis of certain fish or sauropsids. We have analyzed DA in the skeleton of the fox (V. vulpes), using ∼1,000 radiographs of foxes from populations used in the genetic analysis of behavior and morphology. Careful measurements from this robust data base demonstrate that: 1) DA occurs in the limb bones, the ileum, and ischium and in the mandible; 2) regardless of the direction of the length asymmetry vector of a particular skeletal unit, the vectorial direction of length is always opposite to that of width; 3) with the exception of the humerus and radius, there is no correlation or inverse correlation between vectorial amplitudes or magnitudes of bone asymmetries. 4) Postnatal measurements on foxes demonstrate that the asymmetry increases after birth and continues to change (increasing or decreasing) during postnatal growth. 5) A behavior test for preferential use of a specific forelimb exhibited fluctuating asymmetry but not DA. None of the skeletal asymmetries were significantly correlated with a preferential use of a specific forelimb. We suggest that for the majority of fox skeletal parameters, growth on the right and left side of the fox are differentially biased resulting in fixed differences between the two sides in either the rate of growth or the length of the period during which growth occurs. Random effects around these fixed differences perturb the magnitude of the effects such that the magnitudes of length and width asymmetries are not inversely correlated at the level of individual animals. © 2010 Wiley-Liss, Inc.

Furniture dimensions and postural overload for schoolchildren's head, upper back and upper limbs.

PubMed

Batistão, Mariana Vieira; Sentanin, Anna Cláudia; Moriguchi, Cristiane Shinohara; Hansson, Gert-Åke; Coury, Helenice Jane Cote Gil; de Oliveira Sato, Tatiana

2012-01-01

The aim of this study was to evaluate how the fixed furniture dimensions match with students' anthropometry and to describe head, upper back and upper limbs postures and movements. Evaluation was performed in 48 students from a Brazilian state school. Furniture dimensions were measured with metric tape, movements and postures by inclinometers (Logger Tecknologi, Åkarp, Sweden). Seat height was high for 21% and low for 36% of the students; seat length was short for 45% and long for 9% and table height was high for 53% and low for 28%. Regression analysis showed that seat/popliteal height quotient is explained by 90th percentile of upper back inclination (β=0.410) and 90th percentile of right upper arm elevation (β=-0.293). For seat/thigh length quotient the significant variables were 90th percentile of upper back velocity (β=-0.282) and 90th percentile of right upper arm elevation (β=0.410). This study showed a relationship between furniture mismatch and postural overload. When the seat height is low students increase upper back left inclination and right upper arm elevation; when the seat is short students decrease the upper back flexion velocity and increase right upper arm elevation.

Prosthesis rejection in acquired major upper-limb amputees: a population-based survey.

PubMed

Østlie, Kristin; Lesjø, Ingrid Marie; Franklin, Rosemary Joy; Garfelt, Beate; Skjeldal, Ola Hunsbeth; Magnus, Per

2012-07-01

To estimate the rates of primary and secondary prosthesis rejection in acquired major upper-limb amputees (ULAs), to describe the most frequently reported reasons for rejection and to estimate the influence of background factors on the risk of rejection. Cross-sectional study analysing population-based questionnaire data (n = 224). Effects were analysed by logistic regression analyses and Cox regression analyses. Primary prosthesis rejection was found in 4.5% whereas 13.4% had discontinued prosthesis use. The main reasons reported for primary non-wear were a perceived lack of need and discrepancies between perceived need and the prostheses available. The main reasons reported for secondary prosthesis rejection were dissatisfaction with prosthetic comfort, function and control. Primary prosthesis rejection was more likely in ULAs amputated at high age and in ULAs with proximal amputations. Secondary prosthesis rejection was more likely in proximal ULAs and in women. Clinicians should be aware of the increased risk of rejection in proximal ULAs, elderly ULAs and in women. Emphasising individual needs will probably facilitate successful prosthetic fitting. Improved prosthesis quality and individualised prosthetic training may increase long-term prosthesis use. Further studies of the effect of prosthetic training and of the reasons for rejection of different prosthetic types are suggested.

Preinjury and postinjury running analysis along with measurements of strength and tendon length in a patient with a surgically repaired Achilles tendon rupture.

PubMed

Silbernagel, Karin Grävare; Willy, Richard; Davis, Irene

2012-06-01

Case report. The Achilles tendon is the most frequently ruptured tendon, and the incidence of Achilles tendon rupture has increased in the last decade. The rupture generally occurs without any preceding warning signs, and therefore preinjury data are seldom available. This case represents a unique opportunity to compare preinjury running mechanics with postinjury evaluation in a patient with an Achilles tendon rupture. A 23-year-old female sustained a right complete Achilles tendon rupture while playing soccer. Running mechanics data were collected preinjury, as she was a healthy participant in a study on running analysis. In addition, patient-reported symptoms, physical activity level, strength, ankle range of motion, heel-rise ability, Achilles tendon length, and running kinetics were evaluated 1 year after surgical repair. During running, greater ankle dorsiflexion and eversion and rearfoot abduction were noted on the involved side postinjury when compared to preinjury data. In addition, postinjury, the magnitude of all kinetics data was lower on the involved limb when compared to the uninvolved limb. The involved side displayed differences in strength, ankle range of motion, heel rise, and tendon length when compared to the uninvolved side 1 year after injury. Despite a return to normal running routine and reports of only minor limitations with running, considerable changes were noted in running biomechanics 1 year after injury. Calf muscle weakness and Achilles tendon elongation were also found when comparing the involved and uninvolved sides.

Influence of anthropometry on race performance in extreme endurance triathletes: World Challenge Deca Iron Triathlon 2006

PubMed Central

Knechtle, Beat; Knechtle, Patrizia; Andonie, Jorge Luis; Kohler, Götz

2007-01-01

Objective To investigate the influence of anthropometric variables on race performance in ultra‐endurance triathletes in an ultra‐triathlon. Design Descriptive field study. Setting The “World Challenge Deca Iron Triathlon 2006” in Monterrey, Mexico, in which everyday for 10 consecutive days athletes had to perform the distance of one Ironman triathlon of 3.8 km swimming, 180 km cycling and 42.195 km running. Subjects Eight male ultra‐endurance athletes (mean (SD) age 40.6 (10.7) years, weight 76.4 (8.4) kg, height 175 (4) cm and body mass index (BMI) 24.7 (2.2) kg/m2). Interventions None. Main outcome measures Direct measurement of body mass, height, leg length, skinfold thicknesses, limb circumference and calculation of BMI, skeletal muscle mass (SM), percentage SM (%SM) and percentage body fat (%BF) in order to correlate measured and calculated anthropometric variables with race performance. Results Race time was not significantly (p>0.05) influenced by the directly measured variables, height, leg length, body mass, average skinfold thicknesses, or circumference of thigh, calf or upper arm. Furthermore, no significant (p>0.05) correlation was observed between race time and the calculated variables, BMI, %SM and %BF. Conclusions In a multistage ultra‐triathlon over 10 Ironman triathlon distances in 10 consecutive days, there was no effect of body mass, height, leg length, skinfold thicknesses, limb circumference, BMI, %SM or %BF on race performance in the only eight finishers. PMID:17556527

Altered cellular kinetics in growth plate according to alterations in weight bearing.

PubMed

Park, Hoon; Kong, Sun Young; Kim, Hyun Woo; Yang, Ick Hwan

2012-05-01

To examine the effects of change in weight bearing on the growth plate metabolism, a simulated animal model of weightlessness was introduced and the chondrocytes' cellular kinetics was evaluated. Unloading condition on the hind-limb of Sprague-Dawley rats was created by fixing a tail and lifting the hind-limb. Six rats aged 6 weeks old were assigned to each group of unloading, reloading, and control groups of unloading or reloading. Unloading was maintained for three weeks, and then reloading was applied for another one week thereafter. Histomorphometry for the assessment of vertical length of the growth plate, 5-bromo-2'-deoxyuridin immunohistochemistry for cellular kinetics, and biotin nick end labeling transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay for chondrocytes apoptosis in the growth plate were performed. The vertical length of the growth plate and the proliferative potential of chondrocytes were decreased in the unloading group compared to those of control groups. Inter-group differences were more significant in the proliferative and hypertrophic zones. Reloading increased the length of growth plate and proliferative potential of chondrocytes. However, apoptotic changes in the growth plate were not affected by the alterations of weight bearing. Alterations in the weight bearing induced changes in the chondrocytic proliferative potential of the growth plate, however, had no effects on the apoptosis. This may explain why non-weight bearing in various clinical situations hampers normal longitudinal bone growth. Further studies on the factors for reversibility of chondrocytic proliferation upon variable mechanical stresses are needed.

Development of nylon-based artificial muscles for the usage in robotic prosthetic limb

NASA Astrophysics Data System (ADS)

Atikah, Nurul Anis; Weng, Leong Yeng; Anuar, Adzly; Fat, Chau Chien; Abidin, Izham Zainal; Sahari, Khairul Salleh Mohamed

2017-09-01

This paper describes the development of nylon-based artificial muscles that is intended to be used in prosthetic limb for young amputees. Prosthetic limbs are very expensive and this situation is further compounded for young amputees who are very quickly out-grow their prosthesis. The proposed artificial muscles are made of nylon fishing strings from various size such as 0.45mm, 0.55mm, 0.65mm and 1.00mm. These fishing strings were twisted into coils to create Super Coiled Polymers (SCP) and tested using hot air blower. These artificial muscles react counterintuitively, where when it is exposed to heat, contracts, and when cooled, expands. Peltier devices, when switched-on acts as heat pump, where one side is hot and the other is cold. This phenomenon, when affixed in between 2 SCP's, creates tandem motion similar to triceps and biceps. As initial study, the hot side of the Peltier module was tested using these artificial muscles. The string was measured for both its force production, length contraction, the initial results were promising.

Intramedullary stabilization and over-nail lengthening as two-stage treatment of femoral nonunion with shortening. Case study.

PubMed

Kącki, Wojciech; Jasiewicz, Barbara; Radło, Paweł

2014-01-01

Nonunion is one of the most serious complications of long bone fractures. It may be accompanied by a shortening of the segment. The authors describe the case of a 21-year-old woman with a post-traumatic nonunion with shortening of the femur. Treatment was divided into two stages: first, a previously placed nail was removed and new intramedullary stabilization was carried out while bone defects were filled with a bone graft substitute and platelet rich plasma was administered. After the nonunion had healed, the femur was lengthened over an external fixator and an intramedullary nail, resulting in equality of limb length. After eight years of follow-up, the lower limbs remain equal with a properly aligned long axis of the lower limb operated on and a full range of motion in the joints. The treatment strategy described in our article may be an alternative to one-stage surgery if the patient does not consent to it or in the presence of contraindications, but it is associated with a longer treatment time and necessity of additional surgeries.

The effect of military load carriage on 3-D lower limb kinematics and spatiotemporal parameters.

PubMed

Birrell, Stewart A; Haslam, Roger A

2009-10-01

The 3-D gait analysis of military load carriage is not well represented, if at all, within the available literature. This study collected 3-D lower limb kinematics and spatiotemporal parameters in order to assess the subsequent impact of carrying loads in a backpack of up to 32 kg. Results showed the addition of load significantly decreased the range of motion of flexion/extension of the knee and pelvic rotation. Also seen were increases in adduction/abduction and rotation of the hip and pelvis tilt. No changes to ankle kinematics were observed. Alterations to the spatiotemporal parameters of gait were also of considerable interest, namely, an increase in double support and a decrease in preferred stride length as carried load increased. Analysing kinematics during military or recreational load carriage broadens the knowledge regarding the development of exercise-related injuries, while helping to inform the human-centred design process for future load carrying systems. The importance of this study is that limited available research has investigated 3-D lower limb joint kinematics when carrying loads.

Gait as solution, but what is the problem? Exploring cost, economy and compromise in locomotion.

PubMed

Bertram, John E A

2013-12-01

Many studies have examined how legged mammals move, defining 'what' happens in locomotion. However, few ask 'why' those motions occur as they do. The energetic and functional constraints acting on an animal require that locomotion should be metabolically 'cost effective' and this in large part determines the strategies available to accomplish the task. Understanding the gaits utilised, within the spectrum of gaits possible, and determination of the value of specific relationships among speed, stride length, stride frequency and morphology, depends on identifying the fundamental costs involved and the effects of different movement strategies on those costs. It is argued here that a fundamental loss associated with moving on limbs (centre of mass momentum and energy loss) and two costs involved with controlling and replacing that loss (muscular work of the supporting limb during stance and muscular work of repositioning the limbs during swing) interact to determine the cost trade-offs involved and the optimisation strategies available for each species and speed. These optimisation strategies are what has been observed and characterised as gait. Copyright © 2013 Elsevier Ltd. All rights reserved.

Late Cretaceous through Cenozoic strike-slip tectonics of southwestern Alaska

USGS Publications Warehouse

Miller, M.L.; Bradley, D.C.; Bundtzen, T.K.; McClelland, W.

2002-01-01

New geologic mapping and geochronology show that margin-parallel strike-slip faults on the western limb of the southern Alaska orocline have experienced multiple episodes of dextral motion since ~100 Ma. These faults are on the upper plate of a subduction zone ~350-450 km inboard of the paleotrench. In southwestern Alaska, dextral displacement is 134 km on the Denali fault, at least 88-94 km on the Iditarod-Nixon Fork fault, and perhaps tens of kilometers on the Dishna River fault. The strike-slip regime coincided with Late Cretaceous sedimentation and then folding in the Kuskokwim basin, and with episodes of magmatism and mineralization at ~70, ~60, and ~30 Ma. No single driving mechanism can explain all of the ~95 million-year history of strike-slip faulting. Since ~40 Ma, the observed dextral sense of strike slip has run contrary to the sense of subduction obliquity. This may be explained by northward motion of the Pacific plate driving continental margin slivers into and/or around the oroclinal bend. From 44 to 66 Ma, oroclinal rotation, perhaps involving large-scale flexural slip, may have been accompanied by westward escape of crustal blocks along strike-slip faults. However, reconstructions of this period involve unproven assumptions about the identity of the subducting plate, the position of subducting ridges, and the exact timing of oroclinal bending, thus obscuring the driving mechanisms of strike slip. Prior to 66 Ma, oblique subduction is the most plausible driving mechanism for dextral strike slip. Cumulative displacement on all faults of the western limb of the orocline is at least 400 km, about half that on the eastern limb; this discrepancy might be explained by a combination of thrusting and unrecognized strike-slip faulting.

De novo transcriptome sequencing of axolotl blastema for identification of differentially expressed genes during limb regeneration

PubMed Central

2013-01-01

Background Salamanders are unique among vertebrates in their ability to completely regenerate amputated limbs through the mediation of blastema cells located at the stump ends. This regeneration is nerve-dependent because blastema formation and regeneration does not occur after limb denervation. To obtain the genomic information of blastema tissues, de novo transcriptomes from both blastema tissues and denervated stump ends of Ambystoma mexicanum (axolotls) 14 days post-amputation were sequenced and compared using Solexa DNA sequencing. Results The sequencing done for this study produced 40,688,892 reads that were assembled into 307,345 transcribed sequences. The N50 of transcribed sequence length was 562 bases. A similarity search with known proteins identified 39,200 different genes to be expressed during limb regeneration with a cut-off E-value exceeding 10-5. We annotated assembled sequences by using gene descriptions, gene ontology, and clusters of orthologous group terms. Targeted searches using these annotations showed that the majority of the genes were in the categories of essential metabolic pathways, transcription factors and conserved signaling pathways, and novel candidate genes for regenerative processes. We discovered and confirmed numerous sequences of the candidate genes by using quantitative polymerase chain reaction and in situ hybridization. Conclusion The results of this study demonstrate that de novo transcriptome sequencing allows gene expression analysis in a species lacking genome information and provides the most comprehensive mRNA sequence resources for axolotls. The characterization of the axolotl transcriptome can help elucidate the molecular mechanisms underlying blastema formation during limb regeneration. PMID:23815514

Quantitative analysis of tissue deformation dynamics reveals three characteristic growth modes and globally aligned anisotropic tissue deformation during chick limb development.

PubMed

Morishita, Yoshihiro; Kuroiwa, Atsushi; Suzuki, Takayuki

2015-05-01

Tissue-level characterization of deformation dynamics is crucial for understanding organ morphogenetic mechanisms, especially the interhierarchical links among molecular activities, cellular behaviors and tissue/organ morphogenetic processes. Limb development is a well-studied topic in vertebrate organogenesis. Nevertheless, there is still little understanding of tissue-level deformation relative to molecular and cellular dynamics. This is mainly because live recording of detailed cell behaviors in whole tissues is technically difficult. To overcome this limitation, by applying a recently developed Bayesian approach, we here constructed tissue deformation maps for chick limb development with high precision, based on snapshot lineage tracing using dye injection. The precision of the constructed maps was validated with a clear statistical criterion. From the geometrical analysis of the map, we identified three characteristic tissue growth modes in the limb and showed that they are consistent with local growth factor activity and cell cycle length. In particular, we report that SHH signaling activity changes dynamically with developmental stage and strongly correlates with the dynamic shift in the tissue growth mode. We also found anisotropic tissue deformation along the proximal-distal axis. Morphogenetic simulation and experimental studies suggested that this directional tissue elongation, and not local growth, has the greatest impact on limb shaping. This result was supported by the novel finding that anisotropic tissue elongation along the proximal-distal axis occurs independently of cell proliferation. Our study marks a pivotal point for multi-scale system understanding in vertebrate development. © 2015. Published by The Company of Biologists Ltd.

Mirror therapy for improving lower limb motor function and mobility after stroke: A systematic review and meta-analysis.

PubMed

Broderick, P; Horgan, F; Blake, C; Ehrensberger, M; Simpson, D; Monaghan, K

2018-06-01

Mirror therapy has been proposed as an effective intervention for lower limb rehabilitation post stroke. This systematic review with meta-analysis examined if lower limb mirror therapy improved the primary outcome measures of muscle tone and motor function and the secondary outcome measures balance characteristics, functional ambulation, walking velocity, passive range of motion (PROM) for ankle dorsiflexion and gait characteristics in patients with stroke compared to other interventions. Standardised mean differences (SMD) and mean differences (MD) were used to assess the effect of mirror therapy on lower limb functioning. Nine studies were included in the review. Among the primary outcome measures there was evidence of a significant effect of mirror therapy on motor function compared with sham and non-sham interventions (SMD 0.54; 95% CI 0.24-0.93). Furthermore, among the secondary outcome measures there was evidence of a significant effect of mirror therapy for balance capacity (SMD -0.55; 95% CI -1.01 to -0.10), walking velocity (SMD 0.71; 95% CI 0.35-1.07), PROM for ankle dorsiflexion (SMD 1.20; 95% CI 0.71-1.69) and step length (SMD 0.56; 95% CI -0.00 to 1.12). The results indicate that using mirror therapy for the treatment of certain lower limb deficits in patients with stroke may have a positive effect. Although results are somewhat positive, overly favourable interpretation is cautioned due to methodological issues concerning included studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Epidemiologic data of trauma-related lower limb amputees: A single center 10-year experience.

PubMed

Yaşar, Evren; Tok, Fatih; Kesikburun, Serdar; Ada, A Mustafa; Kelle, Bayram; Göktepe, A Salim; Yazıcıoğlu, Kamil; Tan, A Kenan

2017-02-01

The aim of this study is three fold: 1) to introduce epidemiologic data of patients with trauma-related amputations as a 10-year experience of a rehabitation center; 2) to determine comorbidities and secondary conditions of lower limb loss; 3) to determine the rehospitalization reasons for lower limb amputee patients. This retrospective study was conducted in a tertiary rehabilitation center in Turkey. Clinical and demographic data of amputees including sex, age, employment status, time since amputation, time after amputation to first hospitalization, length of hospitalization, how many times the patient was hospitalized, reason for hospitalization, stump complications, comorbid conditions, amputation level and K classifacation were documented. Three hundred ninetynine patients with a mean age of 23,48±6,04 (4-74) years were included in this study. Mean duration after amputation was 119,71±68,86months. Patients were 3,43±2,53 times hospitalized. Landmine explosion was the most common etiology of amputation with 370 patients (92.7%). Below knee amputation was the most common amputation level with 230 (50,77%) amputations. 399 patients were hospitalized 1369 times and the most common hospitalization reason were stump complications (356 times, 26,00%). Spur formation (202 times) was the most common stump complications. Pyscologic disorders were the most common comorbidity with 68 patient (37,56%). Patients with traumatic limb amputations are likely to experience several complications and comorbidities. Prevention of secondary conditions affecting those living with the loss of a limb is an important part of amputee rehabilitation and may prevent rehospitalization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chevron folding patterns and heteroclinic orbits

NASA Astrophysics Data System (ADS)

Budd, Christopher J.; Chakhchoukh, Amine N.; Dodwell, Timothy J.; Kuske, Rachel

2016-09-01

We present a model of multilayer folding in which layers with bending stiffness EI are separated by a very stiff elastic medium of elasticity k2 and subject to a horizontal load P. By using a dynamical system analysis of the resulting fourth order equation, we show that as the end shortening per unit length E is increased, then if k2 is large there is a smooth transition from small amplitude sinusoidal solutions at moderate values of P to larger amplitude chevron folds, with straight limbs separated by regions of high curvature when P is large. The chevron solutions take the form of near heteroclinic connections in the phase-plane. By means of this analysis, values for P and the slope of the limbs are calculated in terms of E and k2.

Limb salvage after infected knee arthroplasty with bone loss and extensor mechanism deficiency using a modular segmental replacement system.

PubMed

Namdari, Surena; Milby, Andrew H; Garino, Jonathan P

2011-09-01

Multiple total knee arthroplasty revisions pose significant surgical challenges, such as bone loss and soft tissue compromise. For patients with bone loss and extensor mechanism insufficiency after total knee arthroplasty, arthrodesis is a treatment option for the avoidance of amputation. However, arthrodesis is both difficult to achieve in situations with massive bone loss and potentially undesirable due to the dramatic shortening that follows. Although intramedullary nailing for knee arthrodesis has been widely reported, this technique has traditionally relied on the achievement of bony union. We report a case of a patient with massive segmental bone loss in which a modular intercalary prosthesis was used for arthrodesis to preserve limb length without bony union. Copyright © 2011 Elsevier Inc. All rights reserved.

Two-stage knee arthrodesis with a modular intramedullary nail due to septic failure of revision total knee arthroplasty with extensor mechanism deficiency.

PubMed

Friedrich, Max J; Schmolders, Jan; Wimmer, Matthias D; Strauss, Andreas C; Ploeger, Milena M; Wirtz, Dieter C; Gravius, Sascha; Randau, Thomas M

2017-10-01

Periprosthetic joint infection is a serious complication and reconstruction after failed revision total knee arthroplasty with significant bone loss and compromised soft-tissues can be challenging. Objective of this study was to assess clinical and functional results, implant survival and infection recurrence rates in patients treated with two-stage arthrodesis after failed revision TKA with extensor mechanism deficiencies due to PJI, and to identify the factors that affect outcomes after surgery. Thirty seven patients with PJI treated within a two-stage exchange and reimplantation of an arthrodesis nail between 2008 and 2014 were included. Systemic and local risk factors were graded preoperatively according to McPherson et al. All patients were treated according to a structured treatment algorithm. Clinical and functional evaluation was performed using the Oxford Knee Score and the Visual Analogue Scale. Thirty two of 37 patients (86.5%) were graded as free of infection. Five patients (13.5%) had recurrent infection after arthrodesis with the need of revision surgery. Mean leg-length discrepancy was 2.2cm. The mean VAS for pain was three, the mean Oxford Knee Score was 38±9. Total implant survival at a 74month follow-up was 74.3% (95% CI: 45.4 to 91.1%), as determined by Kaplan-Meier survival curves. Local McPherson Score, as well as number of revisions was found to be of significant influence to the survival rate. Septic failure of revision knee arthroplasty can be effectively treated with two-stage arthrodesis using a modular intramedullary nail, providing a stable and painless limb with satisfactory functional results and acceptable infection eradication rates. Copyright © 2017 Elsevier B.V. All rights reserved.

[Interposition arthrodesis of the ankle].

PubMed

Vienne, Patrick

2005-10-01

Bony fusion of the ankle in a functionally favorable position for restitution of a painless weight bearing while avoiding a leg length discrepancy. Disabling, painful osteoarthritis of the ankle with extensive bone defect secondary to trauma, infection, or serious deformities such as congenital malformations or diabetic osteoarthropathies. Acute joint infection. Severe arterial occlusive disease of the involved limb. Lateral approach to the distal fibula. Fibular osteotomy 7 cm proximal to the tip of the lateral malleolus and posterior flipping of the distal fibula. Exposure of the ankle. Removal of all articular cartilage and debridement of the bone defect. Determination of the size of the defect and harvesting of a corresponding tricortical bone graft from the iliac crest. Also harvesting of autogenous cancellous bone either from the iliac crest or from the lateral part of the proximal tibia. Insertion of the tricortical bone graft and filling of the remaining defect with cancellous bone. Fixation with three 6.5-mm titanium lag screws. Depending on the extent of the defect additional stabilization of the bone graft with a titanium plate. Fixation of the lateral fibula on talus and tibia with two 3.5-mm titanium screws for additional support. Wound closure in layers. Split below-knee cast with the ankle in neutral position. Between January 2002 and January 2004 this technique was used in five patients with extensive bone defects (four women, one man, average age 57 years [42-77 years]). No intra- or early postoperative complications. The AOFAS (American Orthopedic Foot and Ankle Society) Score was improved from 23 points preoperatively to 76 points postoperatively (average follow-up time of 25 months). Two patients developed a nonunion and underwent a revision with an ankle arthrodesis nail. A valgus malposition after arthrodesis in one patient was corrected with a supramalleolar osteotomy.

Comminuted distal femur closed fractures: a new application of the Ilizarov concept of compression-distraction.

PubMed

El-Tantawy, Ahmad; Atef, Ashraf

2015-04-01

The treatment of intra-articular distal femur fractures with severe metaphyseal comminution is challenging. It is important to choose a technique that provides secure fixation, minimum tissue handling, and early ambulation. The aim of this work was to evaluate the outcomes of application of Ilizarov concept as an early definitive treatment of comminuted distal femur closed fractures. A total of 17 male patients (mean age 28.53±6.33 years) presented with comminuted distal femur fractures (with 10 type C2 and 7 type C3-2 fractures according to AO/ASIF system) were included in this prospective study. Initial fixation of the articular fragments was done by inter-fragmentary screws, percutaneously through a limited open approach, and stabilization was completed by Ilizarov fixator. The procedure included acute shortening, through the comminution, followed by gradual re-distraction to compensate the created shortening. Radiological and functional results were assessed according to ASAMI evaluation system. The mean amount of intra-operative shortening was 3.68±0.53 cm. The mean external fixation index was 37.24±2.53 days/cm. The mean follow-up period was 18.18±1.91 months. All fractures united primarily in an average 137.65±4.12 days, with no evident angular deformity or limb-length discrepancy. None of the cases required a second major procedure or bone graft. The functional results were excellent in three cases, good in 12, and fair in two patients. The Ilizarov concept of acute compression-distraction is a valuable alternative for the treatment of distal femur fractures with severe metaphyseal comminution.

Management of complex femoral nonunion with monorail external fixator: A prospective study.

PubMed

Agrawal, Hemendra Kumar; Garg, Mohit; Singh, Balvinder; Jaiman, Ashish; Khatkar, Vipin; Khare, Shailender; Batra, Sumit; Sharma, Vinod Kumar

2016-01-01

To evaluate 30 patients who underwent distraction osteogenesis with monorail external fixator for complex femoral nonunion. Complex femoral nonunion includes infective non-union, gap nonunion, and limb-length discrepancy secondary to traumatic bone loss, which needs specialized treatment to ensure the functional integrity of femoral bone. 30 patients, including 28 male and 2 female (aged 22-62 years) patients, underwent surgical debridement followed by bone transport with monorail fixator. The lengthening index, radiographic consolidation index, functional status, bone healing, and various problems, obstacles, and complications encountered during the treatment were assessed. Patients underwent a mean of 2.2 (range 1-4) surgeries before presentation. The mean bone defect after surgical debridement was 5.83 cm (range 2-16 cm). The mean treatment duration was 204.7 days (range 113-543 days). The mean lengthening index was 13.06 days/cm with range from 12 to 16 days/cm. Mean maturation index was 23.51 days/cm with range from 17 to 45.5 days/cm. In our study, bone result was excellent in 17, good in 9, fair in 3, and poor in 1 patient. In our study functional outcome is excellent in 9 [30%], good in 14 [46.67%], fair in 5, and poor in 2 patients. In our study, we encountered 34 problems, 17 obstacles, and 8 complications. We concluded that monorail external fixator is an effective treatment option for complex nonunion femoral shaft fracture and its functional outcome is comparable with any other treatment options. Lack of complications and its effectiveness makes monorail external fixator the treatment of choice for complex nonunion femoral shaft.

ATXN2 with intermediate-length CAG/CAA repeats does not seem to be a risk factor in hereditary spastic paraplegia.

PubMed

Nielsen, Troels Tolstrup; Svenstrup, Kirsten; Budtz-Jørgensen, Esben; Eiberg, Hans; Hasholt, Lis; Nielsen, Jørgen E

2012-10-15

Hereditary spastic paraplegia (HSP) confines a group of heterogeneous neurodegenerative disorders characterized by progressive spasticity and lower limb weakness. Age of onset is highly variable even in familial cases with known mutations suggesting that the disease is modulated by other yet unknown parameters. Although progressive gait disturbances, lower limb spasticity and extensor plantar responses are hallmarks of HSP these characteristics are also found in other neurodegenerative disorders, e.g. amytrophic lateral sclerosis (ALS). HSP has been linked to ALS and frontotemporal degeneration with motor neuron disease (FTD-MND), since TDP-43 positive inclusions have recently been found in an HSP subtype, and TDP-43 are found in abundance in pathological inclusions of both ALS and FTD-MND. Furthermore, ataxin-2 (encoded by the gene ATXN2), a polyglutamine containing protein elongated in spinocerebellar ataxia type 2, has been shown to be a modulator of TDP-43 induced toxicity in ALS animal and cell models. Finally, it has been shown that ATXN2 with non-pathogenic intermediate-length CAG/CAA repeat elongations (encoding the polyglutamine tract) is a genetic risk factor of ALS. Considering the similarities in the disease phenotype and the neuropathological link between ALS and HSP we hypothesized that intermediate-length CAG/CAA repeats in ATXN2 could be a modulator of HSP. We show that in a cohort of 181 HSP patients 4.9 % of the patients had intermediate-length CAG/CAA repeats in ATXN2 which was not significantly different from the frequencies in a Danish control cohort or in American and European control populations. However, the mean age of onset was significantly lower in HSP patients with intermediate-length CAG/CAA repeats in ATXN2 compared to patients with normal length repeats. Based on these results we conclude that ATXN2 is most likely not a risk factor of HSP, whereas it might serve as a modulator of age of onset. Copyright © 2012 Elsevier B.V. All rights reserved.

Partial body weight support treadmill training speed influences paretic and non-paretic leg muscle activation, stride characteristics, and ratings of perceived exertion during acute stroke rehabilitation.

PubMed

Burnfield, Judith M; Buster, Thad W; Goldman, Amy J; Corbridge, Laura M; Harper-Hanigan, Kellee

2016-06-01

Intensive task-specific training is promoted as one approach for facilitating neural plastic brain changes and associated motor behavior gains following neurologic injury. Partial body weight support treadmill training (PBWSTT), is one task-specific approach frequently used to improve walking during the acute period of stroke recovery (<1month post infarct). However, only limited data have been published regarding the relationship between training parameters and physiologic demands during this early recovery phase. To examine the impact of four walking speeds on stride characteristics, lower extremity muscle demands (both paretic and non-paretic), Borg ratings of perceived exertion (RPE), and blood pressure. A prospective, repeated measures design was used. Ten inpatients post unilateral stroke participated. Following three familiarization sessions, participants engaged in PBWSTT at four predetermined speeds (0.5, 1.0, 1.5 and 2.0mph) while bilateral electromyographic and stride characteristic data were recorded. RPE was evaluated immediately following each trial. Stride length, cadence, and paretic single limb support increased with faster walking speeds (p⩽0.001), while non-paretic single limb support remained nearly constant. Faster walking resulted in greater peak and mean muscle activation in the paretic medial hamstrings, vastus lateralis and medial gastrocnemius, and non-paretic medial gastrocnemius (p⩽0.001). RPE also was greatest at the fastest compared to two slowest speeds (p<0.05). During the acute phase of stroke recovery, PBWSTT at the fastest speed (2.0mph) promoted practice of a more optimal gait pattern with greater intensity of effort as evidenced by the longer stride length, increased between-limb symmetry, greater muscle activation, and higher RPE compared to training at the slowest speeds. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of Systematic Increases in Treadmill Walking Speed on Gait Kinematics After Stroke

PubMed Central

Tyrell, Christine M.; Roos, Margaret A.; Rudolph, Katherine S.

2011-01-01

Background Fast treadmill training improves walking speed to a greater extent than training at a self-selected speed after stroke. It is unclear whether fast treadmill walking facilitates a more normal gait pattern after stroke, as has been suggested for treadmill training at self-selected speeds. Given the massed stepping practice that occurs during treadmill training, it is important for therapists to understand how the treadmill speed selected influences the gait pattern that is practiced on the treadmill. Objective The purpose of this study was to characterize the effect of systematic increases in treadmill speed on common gait deviations observed after stroke. Design A repeated-measures design was used. Methods Twenty patients with stroke walked on a treadmill at their self-selected walking speed, their fastest speed, and 2 speeds in between. Using a motion capture system, spatiotemporal gait parameters and kinematic gait compensations were measured. Results Significant improvements in paretic- and nonparetic-limb step length and in single- and double-limb support were found. Asymmetry of these measures improved only for step length. Significant improvements in paretic hip extension, trailing limb position, and knee flexion during swing also were found as speed increased. No increases in circumduction or hip hiking were found with increasing speed. Limitations Caution should be used when generalizing these results to survivors of a stroke with a self-selected walking speed of less than 0.4 m/s. This study did not address changes with speed during overground walking. Conclusions Faster treadmill walking facilitates a more normal walking pattern after stroke, without concomitant increases in common gait compensations, such as circumduction. The improvements in gait deviations were observed with small increases in walking speed. PMID:21252308

Retropharyngeal Contralateral C7 Nerve Transfer to the Lower Trunk for Brachial Plexus Birth Injury: Technique and Results.

PubMed

Vu, Anthony T; Sparkman, Darlene M; van Belle, Christopher J; Yakuboff, Kevin P; Schwentker, Ann R

2018-05-01

Brachial plexus birth injuries with multiple nerve root avulsions present a particularly difficult reconstructive challenge because of the limited availability of donor nerves. The contralateral C7 has been described for brachial plexus reconstruction in adults but has not been well-studied in the pediatric population. We present our technique and results for retropharyngeal contralateral C7 nerve transfer to the lower trunk for brachial plexus birth injury. We performed a retrospective review. Any child aged less than 2 years was included. Charts were analyzed for patient demographic data, operative variables, functional outcomes, complications, and length of follow-up. We had a total of 5 patients. Average nerve graft length was 3 cm. All patients had return of hand sensation to the ulnar nerve distribution as evidenced by a pinch test, unprompted use of the recipient limb without mirror movement, and an Active Movement Scale (AMS) of at least 2/7 for finger and thumb flexion; one patient had an AMS of 7/7 for finger and thumb flexion. Only one patient had return of ulnar intrinsic hand function with an AMS of 3/7. Two patients had temporary triceps weakness in the donor limb and one had clinically insignificant temporary phrenic nerve paresis. No complications were related to the retropharyngeal nerve dissection in any patient. Average follow-up was 3.3 years. The retropharyngeal contralateral C7 nerve transfer is a safe way to supply extra axons to the severely injured arm in brachial plexus birth injuries with no permanent donor limb deficits. Early functional recovery in these patients, with regard to hand function and sensation, is promising. Therapeutic V. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

A phylogenetic test for adaptive convergence in rock-dwelling lizards.

PubMed

Revell, Liam J; Johnson, Michele A; Schulte, James A; Kolbe, Jason J; Losos, Jonathan B

2007-12-01

Phenotypic similarity of species occupying similar habitats has long been taken as strong evidence of adaptation, but this approach implicitly assumes that similarity is evolutionarily derived. However, even derived similarities may not represent convergent adaptation if the similarities did not evolve as a result of the same selection pressures; an alternative possibility is that the similar features evolved for different reasons, but subsequently allowed the species to occupy the same habitat, in which case the convergent evolution of the same feature by species occupying similar habitats would be the result of exaptation. Many lizard lineages have evolved to occupy vertical rock surfaces, a habitat that places strong functional and ecological demands on lizards. We examined four clades in which species that use vertical rock surfaces exhibit long hindlimbs and flattened bodies. Morphological change on the phylogenetic branches leading to the rock-dwelling species in the four clades differed from change on other branches of the phylogeny; evolutionary transitions to rock-dwelling generally were associated with increases in limb length and decreases in head depth. Examination of particular characters revealed several different patterns of evolutionary change. Rock-dwelling lizards exhibited similarities in head depth as a result of both adaptation and exaptation. Moreover, even though rock-dwelling species generally had longer limbs than their close relatives, clade-level differences in limb length led to an overall lack of difference between rock- and non-rock-dwelling lizards. These results indicate that evolutionary change in the same direction in independent lineages does not necessarily produce convergence, and that the existence of similar advantageous structures among species independently occupying the same environment may not indicate adaptation.

Long-term Global Morphology of Gravity Wave Activity Using UARS Data

NASA Technical Reports Server (NTRS)

Eckermann, Stephen D.; Jackman, C. (Technical Monitor)

2000-01-01

An extensive body of research this quarter is documented. Further methodical analysis of temperature residuals in Cryogenic Limb Array Etalon Spectrometer (CLAES) Version 8 level 3AT data show signatures during December 1992 at middle and high northern latitudes that, when compared to Naval Research Laboratory/Mountain Wave Forecast Model (NRL)/(MWFM) mountain wave hindcasts, reveal evidence of long mountain waves in these data over Eurasia, Greenland, Scandinavia and North America. The explicit detection of gravity waves in limb-scanned Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures is modeled at length, to derive visibility functions. These insights are used to convert CRISTA gravity wave temperature residuals into data that more closely resemble gravity wave fluctuations detected in data from other satellite instruments, such as Microwave Limb Sounder (MLS), Limb Infrared Monitor of the Stratosphere (LIMS) and Global Positioning System/Meteorology (GPS)/(MET). Finally, newly issued mesospheric temperatures from inversion of CRISTA 15gin emissions are analyzed using a new method that uses separate Kalman fits to the ascending and descending node data. This allows us to study global gravity wave amplitudes at two local times, 12 hours apart. In the equatorial mesosphere, where a large diurnal tidal temperature signal exists, we see modulations of gravity wave activity that are consistent with gravity wave-tidal interactions produced by tidal temperature variability.

Quantitative Comparison of the Walk and Trot of Border Collies and Labrador Retrievers, Breeds with Different Performance Requirements

PubMed Central

Carr, Brittany Jean; Canapp, Sherman O; Zink, M. Christine

2015-01-01

Introduction We hypothesized that breed differences of Border Collies and Labrador Retrievers would be reflected in the temporospatial characteristics of the walk and trot. Materials and Methods Twenty healthy Border Collies and 20 healthy Labrador Retrievers made three passes across a pressure sensing walkway system that recorded quantitative temporospatial information at a walk and a trot. The following variables were measured for each dog: velocity, total pressure index percentage (TPI%), ratio of weight borne on the thoracic vs. pelvic limbs (T/P TPI%), stance time percentage (ST%), and thoracic limb stride length (TSrL). Results The mean T/P TPI% for Border Collies at a walk and at a trot were significantly lower than for Labrador Retrievers (p = 0.0007 and p = 0.0003). Border Collies had a significantly lower ST% than Labrador Retrievers for the thoracic limbs and pelvic limbs at a walk (p = 0.0058 and 0.0003) and the trot (p = 0.0280 and 0.0448). There was no relationship between ST% and TSrL in Border Collies and an inverse correlation between ST% and TSrL in Labrador Retrievers (p = 0.0002). Discussion Key quantitative gait differences were identified in Border Collies and Labrador Retrievers, which could potentially provide each breed with an advantage for their working function. PMID:26689372

Functional assessment of a surgical robot for reduction of lower limb fractures.

PubMed

Hung, Shuo-Suei; Lee, Ming-Yih

2010-12-01

This paper presents a novel robot designed for reduction of lower limb fractures, with the additional features of automatic controlled flexion of the knee joint, individual traction of thigh and leg, and foot rotation. The aim of this design is to assist the orthopaedic surgeon to perform better fracture reduction through motor control, in contrast to current manual control, and the results of assessments of its functions on normal subjects are presented in this paper. The robot was designed to be mounted onto the operation table, and was controlled through open switch relay. Functional assessments were conducted on six healthy volunteers in terms of knee joint motion and lower limb traction; measurement of angle and distance was calculated from data obtained by a 3D ultrasonic motion system (Zebris(®) ). The results showed a good correlation of the flexion angle between the robot and the subjects at the knee joint. In the traction tests, a steady lengthening of the proximal as well as the distal segment of the robot was observed, and a slight increase in subjects' limb length was also recorded, which might be due to distraction in the joint space. This automatic control fracture table has distinct features compared with the conventional ones, and it is believed to be of assistance to surgeons when performing fracture fixations. Copyright © 2010 John Wiley & Sons, Ltd.

High-resolution 3D volumetry versus conventional measuring techniques for the assessment of experimental lymphedema in the mouse hindlimb

PubMed Central

Frueh, Florian S.; Körbel, Christina; Gassert, Laura; Müller, Andreas; Gousopoulos, Epameinondas; Lindenblatt, Nicole; Giovanoli, Pietro; Laschke, Matthias W.; Menger, Michael D.

2016-01-01

Secondary lymphedema is a common complication of cancer treatment characterized by chronic limb swelling with interstitial inflammation. The rodent hindlimb is a widely used model for the evaluation of novel lymphedema treatments. However, the assessment of limb volume in small animals is challenging. Recently, high-resolution three-dimensional (3D) imaging modalities have been introduced for rodent limb volumetry. In the present study we evaluated the validity of microcomputed tomography (μCT), magnetic resonance imaging (MRI) and ultrasound in comparison to conventional measuring techniques. For this purpose, acute lymphedema was induced in the mouse hindlimb by a modified popliteal lymphadenectomy. The 4-week course of this type of lymphedema was first assessed in 6 animals. In additional 12 animals, limb volumes were analyzed by μCT, 9.4 T MRI and 30 MHz ultrasound as well as by planimetry, circumferential length and paw thickness measurements. Interobserver correlation was high for all modalities, in particular for μCT analysis (r = 0.975, p < 0.001). Importantly, caliper-measured paw thickness correlated well with μCT (r = 0.861), MRI (r = 0.821) and ultrasound (r = 0.800). Because the assessment of paw thickness represents a time- and cost-effective approach, it may be ideally suited for the quantification of rodent hindlimb lymphedema. PMID:27698469

Subtasks affecting step-length asymmetry in post-stroke hemiparetic walking.

PubMed

Kim, Woo-Sub

2016-10-01

This study was performed to investigate whether components from trunk progression (TP) and step length were related to step length asymmetry in walking in patients with hemiparesis. Gait analysis was performed for participants with hemiparesis and healthy controls. The distance between the pelvis and foot in the anterior-posterior axis was calculated at initial-contact. Step length was partitioned into anterior foot placement (AFP) and posterior foot placement (PFP). TP was partitioned into anterior trunk progression (ATP) and posterior trunk progression (PTP). The TP pattern and step length pattern were defined to represent intra-TP and intra-step spatial balance, respectively. Of 29 participants with hemiparesis, nine participants showed longer paretic step length, eight participants showed symmetric step length, and 12 participants showed shorter paretic step length. For the hemiparesis group, linear regression analysis showed that ATP asymmetry, AFP asymmetry, and TP patterns had significant predictability regarding step length asymmetry. Prolonged paretic ATP and shortened paretic AFP was the predominant pattern in the hemiparesis group, even in participants with symmetric step length. However, some participants showed same direction of ATP and AFP asymmetry. These findings indicate the following: (1) ATP asymmetries should be observed to determine individual characteristics of step length asymmetry, and (2) TP patterns can provide complementary information for non-paretic limb compensation. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of Discordant Views in the Management of Descending Thoracic Aortic Aneurysm.

PubMed

Chiu, Peter; Sailer, Anna-Margaretha; Baiocchi, Michael; Goldstone, Andrew B; Schaffer, Justin M; Trojan, Jeff; Fleischmann, Dominik; Mitchell, R Scott; Miller, D Craig; Dake, Michael D; Woo, Y Joseph; Lee, Jason T; Fischbein, Michael P

2017-01-01

Thoracic endovascular aortic repair has a lower perceived risk than open surgical repair and has become an increasingly popular alternative. Whether general consensus exists regarding candidacy for either operation among open and endovascular specialists is unknown. A retrospective review of isolated descending thoracic aortic aneurysm at our institution between January 2005 and October 2015 was performed, excluding trauma and dissection. Two cardiac surgeons, 2 cardiovascular surgeons, 1 vascular surgeon, and 1 interventional radiologist gave their preference for open vs endovascular repair. Interobserver agreement was assessed with the kappa coefficient. k-means clustering agnostically grouped various patterns of agreement. The mean rating was predicted using least absolute shrinkage and selection operator regression. Negative binomial regression predicted the discrepancy between our panel of raters and the historical operation. Generalized estimating equation modeling was then used to evaluate the association between the extent of discrepancy and the adverse perioperative outcome. There were 77 patients with preoperative imaging studies. Pairwise interobserver agreement was only fair (median weighted kappa 0.270 [interquartile range 0.211-0.404]). Increasing age and proximal neck length predicted an increasing preference for thoracic endovascular aortic repair in our panel; larger proximal neck diameter predicted a general preference for open surgical repair. Increasing proximal neck diameter predicted a larger discrepancy between our panel and the historical operation. Greater discrepancy was associated with adverse outcome. Substantial disagreement existed among our panel, and an exploratory analysis of the effect of increasing discrepancy demonstrated an association with adverse perioperative outcome. An investigation of the effect of a thoracic aortic team with open and endovascular specialists is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Modified classification and single-stage microsurgical repair of posttraumatic infected massive bone defects in lower extremities.

PubMed

Yang, Yun-fa; Xu, Zhong-he; Zhang, Guang-ming; Wang, Jian-wei; Hu, Si-wang; Hou, Zhi-qi; Xu, Da-chuan

2013-11-01

Posttraumatic infected massive bone defects in lower extremities are difficult to repair because they frequently exhibit massive bone and/or soft tissue defects, serious bone infection, and excessive scar proliferation. This study aimed to determine whether these defects could be classified and repaired at a single stage. A total of 51 cases of posttraumatic infected massive bone defect in lower extremity were included in this study. They were classified into four types on the basis of the conditions of the bone defects, soft tissue defects, and injured limb length, including Type A (without soft tissue defects), Type B (with soft tissue defects of 10 × 20 cm or less), Type C (with soft tissue defects of 10 × 20 cm or more), and Type D (with the limb shortening of 3 cm or more). Four types of single-stage microsurgical repair protocols were planned accordingly and implemented respectively. These protocols included the following: Protocol A, where vascularized fibular graft was implemented for Type A; Protocol B, where vascularized fibular osteoseptocutaneous graft was implemented for Type B; Protocol C, where vascularized fibular graft and anterior lateral thigh flap were used for Type C; and Protocol D, where limb lengthening and Protocols A, B, or C were used for Type D. There were 12, 33, 4, and 2 cases of Types A, B, C, and D, respectively, according to this classification. During the surgery, three cases of planned Protocol B had to be shifted into Protocol C; however, all microsurgical repairs were completed. With reference to Johner-Wruhs evaluation method, the total percentage of excellent and good results was 82.35% after 6 to 41 months of follow-up. It was concluded that posttraumatic massive bone defects could be accurately classified into four types on the basis of the conditions of bone defects, soft tissue coverage, and injured limb length, and successfully repaired with the single-stage repair protocols after thorough debridement. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Minimizing Leg Length Discrepancy After Intramedullary Nailing of Comminuted Femoral Shaft Fractures: A Quality Improvement Initiative Using the Scout Computed Tomography Scanogram.

PubMed

Gheraibeh, Petra; Vaidya, Rahul; Hudson, Ian; Meehan, Robert; Tonnos, Frederick; Sethi, Anil

2018-05-01

To prevent leg length discrepancy (LLD) after locked femoral nailing in patients with comminuted femoral shaft fractures. Prospective consecutive case series aimed at quality improvement. Level 1 Trauma Center PATIENTS:: Ninety-eight consecutive patients with a comminuted femoral shaft fracture underwent statically locked intramedullary nailing, with a focused attempt at minimizing LLD during surgery. A computed tomography scanogram of both legs was performed on postoperative day 1 to assess for residual LLD. Patients were offered the option to have LLD >1.5 cm corrected before discharge. LLD >1.5 cm. Twenty-one patients (21.4%) were found to have an LLD >1.5 cm. An LLD >1.5 cm occurred in 10/55 (18%) antegrade nail patients and 11/43 (26%) retrograde nail patients (P = 0.27). No difference was noted based on the mechanism of injury, surgeon training and OTA/AO type B versus C injury. Ninety of 98 patients left with <1.5 cm LLD, 13/21 had a correction all to ≤0.6 cm, and 8 decided to accept the LLD and declined early correction. No patient left the hospital with an LLD >1.5 cm after locked intramedullary nailing for a comminuted femoral shaft fracture without being informed and the option of early correction. We recommend using a full-length computed tomography scanogram after IM nailing of comminuted femur fractures to prevent iatrogenic LLD. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Negligence claims in UK total hip arthroplasty: a series of 167 consecutive cases.

PubMed

Whittingham-Jones, Paul; Williams, D; Raja, S; Bridle, S; Bircher, M

2012-01-01

A review of negligence reports, detailing 227 complaints from the practices of two orthopedic surgeons, was undertaken. There were demonstrable differences in the number of complaints over leg-length discrepancy; femoral fracture and cup malposition when cemented versus uncemented implants were compared. Surgeons must appreciate the less forgiving nature of uncemented hip implants and the importance of preoperative planning particularly in the presence of abnormal anatomy.

Atrophic femoral nonunion with bone loss: treatment with monorail transport: a case report.

PubMed

Gay, David M; Voss, Frank R

2004-08-01

Nonunions are an uncommon outcome of femoral fractures. Atrophic nonunions with a leg length discrepancy secondary to bone loss are often the most difficult to treat, and the treatment options are limited. We present a case that uses concomitant monolateral external fixation and intramedullary nailing to heal a nonunion and perform a simultaneous 7-cm lengthening procedure in a 33-year-old female.

The accuracy of climate models' simulated season lengths and the effectiveness of grid scale correction factors

DOE PAGES

Winterhalter, Wade E.

2011-09-01

Global climate change is expected to impact biological populations through a variety of mechanisms including increases in the length of their growing season. Climate models are useful tools for predicting how season length might change in the future. However, the accuracy of these models tends to be rather low at regional geographic scales. Here, I determined the ability of several atmosphere and ocean general circulating models (AOGCMs) to accurately simulate historical season lengths for a temperate ectotherm across the continental United States. I also evaluated the effectiveness of regional-scale correction factors to improve the accuracy of these models. I foundmore » that both the accuracy of simulated season lengths and the effectiveness of the correction factors to improve the model's accuracy varied geographically and across models. These results suggest that regional specific correction factors do not always adequately remove potential discrepancies between simulated and historically observed environmental parameters. As such, an explicit evaluation of the correction factors' effectiveness should be included in future studies of global climate change's impact on biological populations.« less

The role of Euler buckling instability in the fabrication of nanoelectromechanical systems on the basis of GaAs/AlGaAs heterostructures

NASA Astrophysics Data System (ADS)

Shevyrin, A. A.; Pogosov, A. G.; Budantsev, M. V.; Bakarov, A. K.; Toropov, A. I.; Ishutkin, S. V.; Shesterikov, E. V.; Kozhukhov, A. S.; Kosolobov, S. S.; Gavrilova, T. A.

2012-12-01

Mechanical stresses are investigated in suspended nanowires made on the basis of GaAs/AlGaAs heterostructures. Though there are no intentionally introduced stressor layers in the heterostructure, the nanowires are subject to Euler buckling instability. In the wide nanowires, the out-of-plane buckling is observed at length significantly smaller (3 times) than the theoretically estimated critical value, while in the narrow nanowires, the experimentally measured critical length of the in-plane buckling coincides with the theoretical estimation. The possible reasons for the obtained discrepancy are considered. The observed peculiarities should be taken into account in the fabrication of nanomechanical and nanoelectromechanical systems.

A Reevaluation of X-Irradiation Induced Phocomelia and Proximodistal Limb Patterning

PubMed Central

Galloway, Jenna L.; Delgado, Irene; Ros, Maria A.; Tabin, Clifford J.

2009-01-01

Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a dramatic increase in incidence in the early 1960’s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative1, 2. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation3-5. Both X-irradiation5 and thalidomide-induced phocomelia5, 6 have been interpreted as patterning defects in the context of the Progress Zone Model, which states that a cell’s proximodistal (PD) identity is determined by the length of time spent in a distal limb region termed the “Progress Zone” 7. Indeed, studies of X-irradiation induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the Progress Zone Model. Here, using a combination of molecular analysis and lineage tracing, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. As skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the etiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that PD patterning is unaffected following X-irradiation does not support the predictions of the Progress Zone Model. PMID:19553938

A reevaluation of X-irradiation-induced phocomelia and proximodistal limb patterning.

PubMed

Galloway, Jenna L; Delgado, Irene; Ros, Maria A; Tabin, Clifford J

2009-07-16

Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a marked increase in incidence in the early 1960s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation. Both X-irradiation and thalidomide-induced phocomelia have been interpreted as patterning defects in the context of the progress zone model, which states that a cell's proximodistal identity is determined by the length of time spent in a distal limb region termed the 'progress zone'. Indeed, studies of X-irradiation-induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the progress zone model. Here, using a combination of molecular analysis and lineage tracing in chick, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. Because skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the aetiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that proximodistal patterning is unaffected after X-irradiation does not support the predictions of the progress zone model.

Claw and limb disorders in 12 Norwegian beef-cow herds

PubMed Central

Fjeldaas, Terje; Nafstad, Ola; Fredriksen, Bente; Ringdal, Grethe; Sogstad, Åse M

2007-01-01

Background The main aim of the study was to assess the prevalence of claw and limb disorders in Norwegian beef-cow herds. Methods Twenty-six herds with ≥15 cow-years were selected by computerized systematic assignment from the three most beef cattle-dense regions of Norway. The study population consisted of 12 herds with 28 heifers and 334 cows. The animals were trimmed and examined once by claw trimmers during the late winter and spring of 2003. The seven claw trimmers had been taught diagnosing and recording of claw lesions. Environment, feeding and management routines, age and breed, culling and carcass characteristics were also recorded. Results Lameness was recorded in 1.1% of the animals, and only in hind claws. Pericarpal swellings were recorded in one animal and peritarsal lesions in none. In total, claw and limb disorders including lameness were recorded in 29.6% of the animals, 4.1% with front and 28.2% with hind limb disorders, respectively. Most lesions were mild. Laminitis-related claw lesions were recorded in 18.0% of the animals and infectious lesions in 16.6%. The average claw length was 84 mm in front claws and 89 mm in hind claw. Both laminitis-related and infectious claw lesions were more prevalent with increasing age. Carcasses from animals with claw and limb disorders were on average 34 kg heavier than carcasses from animals without such disorders (p = 0.02). Our results also indicate association between some management factors and claw lesions. Conclusion The study shows that the prevalence of lameness was low in 12 Norwegian beef-cow herds compared to beef-cattle herds in other countries and also that there were less claw and limb disorders in these herds compared to foreign dairy-cattle herds. The prevalence of lameness and white-line fissures was approximately the same as in Norwegian dairy herds whereas less dermatitis, heel-horn erosions, haemorrhages of the sole and the white line and sole ulcers were recorded. PMID:17892582

The influence of the Re-Link Trainer on gait symmetry in healthy adults.

PubMed

Ward, Sarah; Wiedemann, Lukas; Stinear, Cathy; Stinear, James; McDaid, Andrew

2017-07-01

Walking function post-stroke is characterized by asymmetries in gait cycle parameters and joint kinematics. The Re-Link Trainer is designed to provide kinematic constraint to the paretic lower limb, to guide a physiologically normal and symmetrical gait pattern. The purpose of this pilot study was to assess the immediate influence of the Re-Link Trainer on measures of gait symmetry in healthy adults. Participants demonstrated a significantly lower cadence and a 62% reduction in walking speed in the Re-Link Trainer compared to normal walking. The step length ratio had a significant increase from 1.0 during normal walking to 2.5 when walking in the Re-Link Trainer. The results from this pilot study suggest in its current iteration the Re-Link Trainer imposes an asymmetrical constraint on lower limb kinematics.

A previously undescribed syndrome combining fibular agenesis/hypoplasia, oligodactylous clubfeet, anonychia/ungual hypoplasia, and other defects.

PubMed

Santos, Silvana C; Pardono, Eliete; Ferreira da Costa, Maria Ione; de Melo, Aurea Nogueira; Graciani, Zodja; de Albuquerque e Souza, Alessandra Cavalcanti; Lezirovitz, Karina; Thiele-Aguiar, Renata Soares; Mingroni-Netto, Regina Célia; Opitz, John M; Kok, Fernando; Otto, Paulo A

2008-12-15

We describe an apparently new genetic syndrome in six members of a family living in a remote area in Northeastern Brazil. This syndrome comprises: short stature due to a marked decrease in the length of the lower limbs (predominantly mesomelic with fibular agenesis/marked hypoplasia), grossly malformed/deformed clubfeet with severe oligodactyly, upper limbs with acromial dimples and variable motion limitation of the forearms and/or hands, severe nail hypoplasia/anonychia sometimes associated with mild brachydactyly and occasionally with pre-axial polydactyly. This syndrome is apparently distinct from the syndrome of brachydactyly-ectrodactyly with fibular aplasia or hypoplasia (OMIM 113310), the syndrome of fibular aplasia or hypoplasia, femoral bowing and poly-, syn-, and oligodactyly (OMIM 228930), and from other previously described conditions exhibiting fibular agenesis/hypoplasia. Copyright (c) 2008 Wiley-Liss, Inc.

Investigation of the dependence of joint contact forces on musculotendon parameters using a codified workflow for image-based modelling.

PubMed

Modenese, Luca; Montefiori, Erica; Wang, Anqi; Wesarg, Stefan; Viceconti, Marco; Mazzà, Claudia

2018-05-17

The generation of subject-specific musculoskeletal models of the lower limb has become a feasible task thanks to improvements in medical imaging technology and musculoskeletal modelling software. Nevertheless, clinical use of these models in paediatric applications is still limited for what concerns the estimation of muscle and joint contact forces. Aiming to improve the current state of the art, a methodology to generate highly personalized subject-specific musculoskeletal models of the lower limb based on magnetic resonance imaging (MRI) scans was codified as a step-by-step procedure and applied to data from eight juvenile individuals. The generated musculoskeletal models were used to simulate 107 gait trials using stereophotogrammetric and force platform data as input. To ensure completeness of the modelling procedure, muscles' architecture needs to be estimated. Four methods to estimate muscles' maximum isometric force and two methods to estimate musculotendon parameters (optimal fiber length and tendon slack length) were assessed and compared, in order to quantify their influence on the models' output. Reported results represent the first comprehensive subject-specific model-based characterization of juvenile gait biomechanics, including profiles of joint kinematics and kinetics, muscle forces and joint contact forces. Our findings suggest that, when musculotendon parameters were linearly scaled from a reference model and the muscle force-length-velocity relationship was accounted for in the simulations, realistic knee contact forces could be estimated and these forces were not sensitive the method used to compute muscle maximum isometric force. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Mechanical interaction between neighboring muscles in human upper limb: Evidence for epimuscular myofascial force transmission in humans.

PubMed

Yoshitake, Yasuhide; Uchida, Daiki; Hirata, Kosuke; Mayfield, Dean L; Kanehisa, Hiroaki

2018-06-06

To confirm the existence of epimuscular myofascial force transmission in humans, this study examined if manipulating joint angle to stretch the muscle can alter the shear modulus of a resting adjacent muscle, and whether there are regional differences in this response. The biceps brachii (BB: manipulated muscle) and the brachialis (BRA: resting adjacent muscle) were deemed suitable for this study because they are neighboring, yet have independent tendons that insert onto different bones. In order to manipulate the muscle length of BB only, the forearm was passively set at supination, neutral, and pronation positions. For thirteen healthy young adult men, the shear modulus of BB and BRA was measured with shear-wave elastography at proximal and distal muscle regions for each forearm position and with the elbow joint angle at either 100° or 160°. At both muscle regions and both elbow positions, BB shear modulus increased as the forearm was rotated from a supinated to pronated position. Conversely, BRA shear modulus decreased as function of forearm position. The effect of forearm position on shear modulus was most pronounced in the distal muscle region when the elbow was at 160°. The observed alteration of shear modulus of the resting adjacent muscle indicates that epimuscular myofascial force transmission is present in the human upper limb. Consistent with this assertion, we found that the effect of muscle length on shear modulus in both muscles was region-dependent. Our results also suggest that epimuscular myofascial force transmission may be facilitated at stretched muscle lengths. Copyright © 2018 Elsevier Ltd. All rights reserved.

Radiation pressure: A possible cause for the superrotation of the Venusian atmosphere

NASA Technical Reports Server (NTRS)

Krause, J. L.

1992-01-01

The superrotation of the venusian atmosphere relative to the planet's surface has long been known. Yet the process by which this vigorous circulation is maintained is poorly understood. The purpose of this report is to show that a mechanism by which the solar radiation interacts with the cloudy atmosphere of Venus could be the principle cause of the superrotation. It has been long known that Venus has a high albedo due to the scattering (similar to the reflection process) of solar radiation by the cloud droplets in its atmosphere. The radiation not scattered, but intercepted by the planet and its atmosphere, is mainly absorbed within the cloud layers. Therefore, momentum (equal, more or less, to that of the solar radiation intercepted) is continually transferred to the venusian atmosphere. The atmospheric system presents a symmetrical surface (same radiation-matter interaction) toward the solar radiation at its morning and evening limbs. If the cross-sectional areas at both limbs were equal, the momentum transfer at the morning limb would decelerate the atmosphere's rotation while at the evening limb the same transfer would accelerate the rotation an equal amount. The net result of this is that the overall rate of rotation would be unchanged. Such a symmetrical configuration is not likely since the atmosphere must be warmed as it rotates across the planet's day hemisphere and cooled as it rotates across the planet's night hemisphere. This warming and cooling must result in a formation of an asymmetrical configuration. It is apparent that the momentum transfer at the evening limb must be greater than that at the morning limb because the atmosphere's greater cross section at the evening limb intercepts a greater amount of solar radiation. It should be noted that very little of the solar radiation is transmitted through the cloud layers, especially at or near the limbs where the atmospheric path length of the radiation is long. This net momentum transfer must be continually added to the angular momentum of the atmospheric system at the same time angular momentum is continually removed from the atmosphere by the frictional drag imposed on the atmosphere by the slowly rotating planet's surface. This completes the description of this mechanism.

[Clinical application of ultrasound guided Fogarty balloon catheter in arterial crisis].

PubMed

Li, Xiaodong; Wang, Pei; Yu, Changyu; Yan, Xiaowei; Yin, Jing

2017-10-01

To explore the effectiveness of arterial crisis after replantation of limb treated by ultrasound guided Fogarty balloon catheter. Between January 2012 and July 2016, 27 patients suffered from arterial crisis after replantation of limb were treated with ultrasound guided Fogarty balloon catheter combined with thrombolytic anticoagulant. There were 18 males and 9 females with the age of 19-51 years (mean, 32 years). The limb mutilation position was at knee joint in 3 cases, lower limb in 9 cases, ankle joint in 6 cases, elbow joint in 2 cases, forearm in 4 cases, and wrist joint in 3 cases. The arterial crisis happened at 2.5-18 hours (mean, 7.5 hours) after limb replantation surgery. Color doppler ultrasonography was used to diagnose the arterial thrombosis, finally the anastomotic thrombosis were found in 16 cases, non-anastomotic thrombosis in 7 cases, and combined thrombosis in 4 cases. All the thrombosis were deteced in the arteries with the length of 0.8-3.9 cm. No complication such as vascular perforation, rupture, air embolism, thromboembolism, wound infection, or sepsis happened after operation. Arterial crisis occurred again in 3 cases at 1.5-13.5 hours after limb replantation and treated by arterial exploration, 1 case was treated successfully; 2 cases had arterial occlusion and partial necrosis of limb, and got amputation treatment at last. The rest 24 cases survived with the incision healing by first stage. In the 24 cases, 1 case suffered from acute myonephropathic metabolic syndrome and corrected after hemodialysis; 1 case suffered from acute liver functional damage and corrected by comprehensive treatment of internal medicine. The 24 patients were followed up 7-38 months (mean, 11 months). At last follow-up, blood supply of the limb was good with normal skin temperature and improved sense of feeling, activity, and swelling. According to Chinese Medical Association of hand surgery to the upper extremity function assessment standard, the results were excellent in 12 cases, good in 8 cases, and fair in 4 cases with an excellent and good rate of 83.3%. Ultrasound guided Fogarty balloon catheter treatment of posterior replantation of arterial crisis can accurately locate the thrombosis, get the thrombus fast and invasive minimally to avoid the blind and repeated thrombectomy, and obtain certain effectiveness.

Three-Dimensional Kinematic Gait Analysis of Doberman Pinschers with and without Cervical Spondylomyelopathy

PubMed Central

Foss, K.; da Costa, R.C.; Moore, S.

2014-01-01

Background The optimal treatment of cervical spondylomyelopathy (CSM) is controversial, with the owner’s and clinician’s perception of gait improvement often being used as outcome measures. These methods are subjective and suffer from observer bias. Objectives To establish kinematic gait parameters utilizing digital motion capture in normal Doberman Pinschers and compare them with CSM-affected Dobermans. Animals Nineteen Doberman Pinschers; 10 clinically normal and 9 with CSM. Methods All dogs were enrolled prospectively and fitted with a Lycra® body suit, and motion capture was performed and used to reconstruct a 3-D stick diagram representation of each dog based on 32 reflective markers, from which several parameters were measured. These included stride duration, length, and height; maximal and minimal spinal angles; elbow and stifle flexion and extension; and maximum and minimum distances between the thoracic and pelvic limbs. A random-effects linear regression model was used to compare parameters between groups. Results Significant differences between groups included smaller minimum (mean = 116 mm; P = .024) and maximum (mean = 184 mm; P = .001) distance between the thoracic limbs in CSM-affected dogs. Additionally, thoracic limb stride duration was also smaller (P = .009) in CSM-affected dogs (mean = 0.7 seconds) when compared with normal dogs (mean = 0.8 seconds). In the pelvic limbs, the average stifle flexion (mean = 100°; P = .048) and extension (mean = 136°; P = .009), as well as number of strides (mean = 2.7 strides; P = .033) were different between groups. Conclusions and Clinical Importance Our findings suggest that computerized gait analysis reveals more consistent kinematic differences in the thoracic limbs, which can be used as future objective outcome measures. PMID:23194100

Mid-Term Outcomes of Endovascular Treatment for TASC-II D Femoropopliteal Occlusive Disease with Critical Limb Ischemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torres-Blanco, Álvaro, E-mail: atorres658@yahoo.es; Edo-Fleta, Gemma; Gómez-Palonés, Francisco

2016-03-15

PurposeThe purpose of the study was to assess the safety and midterm effectiveness of endovascular treatment in Trans-Atlantic Inter-Society Consensus II (TASC-II) D femoropopliteal occlusions in patients with critical limb ischemia (CLI).MethodsPatients with CLI who underwent endovascular treatment for TASC-D de novo femoropopliteal occlusive disease between September 2008 and December 2013 were selected. Data included anatomic features, pre- and postprocedure ankle-brachial index, duplex ultrasound, and periprocedural complications. Sustained clinical improvement, limb salvage rate, freedom from target lesion revascularization (TLR), and freedom from target extremity revascularization (TER) were assessed by Kaplan–Meier estimation and predictors of restenosis/occlusion with Cox analysis.ResultsThirty-two patients underwentmore » treatment of 35 TASC-D occlusions. Mean age was 76 ± 9. Mean lesion length was 23 ± 5 cm. Twenty-eight limbs (80 %) presented tissue loss. Seventeen limbs underwent treatment by stent, 13 by stent-graft, and 5 by angioplasty. Mean follow-up was 29 ± 20 months. Seven patients required major amputation and six patients died during follow-up. Eighteen endovascular and three surgical TLR procedures were performed due to restenosis or occlusion. Estimated freedom from TLR and TER rates at 2 years were 41 and 76 %, whereas estimated primary and secondary patency rates were 41 and 79 %, respectively.ConclusionsEndovascular treatment for TASC II D lesions is safe and offers satisfying outcomes. This patient subset would benefit from a minimally invasive approach. Follow-up is advisable due to a high rate of restenosis. Further follow-up is necessary to know the long-term efficacy of these procedures.« less

[Application of orientation to the mechanical alignment of lower limbs in operation of high tibial osteotomy].

PubMed

Hu, Yue-Zheng; Wen, Hong; Pan, Xiao-Yun; Yu, Hua-Chen

2012-09-01

To evaluate the effects of orientation to the mechanical alignment of lower limbs in high tibial osteotomy (HTO). From March 2005 to July 2010, the data of 57 patients (63 knees) with medial compartment osteoarthritis were retrospectively analyzed. There were 24 males and 33 females with an average age of 52 years (ranged, 34 to 68). HTO was used in all the patients, and with wire the exact orientation to the mechanical alignment of lower limbs was performed in order to obtain good angle of intercepted bone. X-rays of full-length lower limbs were done at the 3rd month after operation and final follow-up, in which femorotibial angle would be observed. Clinical results were evaluated according to Hospital for Special Surgery knee scores (HSS) including pain, function, activities, myodynamia, deformity and instability. All patients were followed up from 24 to 60 months with an average of 36.7 months. All osteotomy site achieved radiographic healing. The femorotibial angle was corrected from preoperative (182.8 +/- 2.9) degrees to postoperative (167.6 +/- 2.5) degrees and (168.1 +/- 2.5) degrees at final follow-up (compared with preoperative data, P < 0.01). Pain relieved and genu valgum recovered. HSS score improved from preoperative 69.5 +/- 7.1 to postoperative 91.1 +/- 4.9 and 92.2 +/- 5.6 at final follow-up. According to HSS standard, 43 knees got excellent results, 18 good and 2 fair. The orientation to mechanical alignment of lower limbs using wire during operation of HTO is a good method in correcting femorotibial angle and treating medial compartment osteoarthritis of the knee. Moreover, the method is simple and precise for orthopedist.

Conservative Treatment of Distal Radius Fractures: A Prospective Descriptive Study.

PubMed

Aparicio, Pilar; Izquierdo, Óscar; Castellanos, Juan

2017-06-01

Disability of the upper limb is one of the consequences of distal radius fracture (DRF). The outcome of DRF treatment is based on objective clinical variables, as strength or range of movement (ROM); sometimes these variables do not correlate with the functional level of the patient. The principal objective of our study was to assess the repercussion of conservative treatment of DRF on upper limb disability. This is a retrospective review of prospectively collected data. We collected data of 61 nonconsecutive DRFs treated conservatively from July 2007 to August 2008. Average Disabilities of the Arm, Shoulder and Hand (DASH) score before fracture was 20.8 points; average DASH score after the fracture was 42.6. There was a significant increase in the upper limb disability after 1 year of follow-up in the patients treated conservatively ( P < .001; size effect, 1.06). Average radial inclination, radial tilt, and radial length were 18.18°, 3.35°, and 5.76 mm, respectively. Average ROM for flexion-extension was 100.6° and for pronation-supination 144.0°. ROM for flexion-extension of the unaffected wrist was 128.2° and for pronation-supination 172.4°. We did not find any significant statistical correlation between the increase in disability and the decrease in the ROM ( P > .05). We did not find any significant statistical correlation between the increase in the disability and the worsening in the radiological parameters ( P > .05). Our results confirm the hypothesis that the conservative treatment of DRF produced an increase in the upper limb disability after 1 year of follow-up. Our study does not show a correlation between the increase in upper limb disability and the decrease in wrist ROM. Our study did not find a correlation between radiological measures and DASH scores.

Results of a bone splint technique for the treatment of lower limb deformities in children with type I osteogenesis imperfecta

PubMed Central

Lin, Dasheng; Zhai, Wenliang; Lian, Kejian; Ding, Zhenqi

2013-01-01

Background: Children with osteogenesis imperfecta (OI) can suffer from frequent fractures and limb deformities, resulting in impaired ambulation. Osteopenia and thin cortices complicate orthopedic treatment in this group. This study evaluates the clinical results of a bone splint technique for the treatment of lower limb deformities in children with type I OI. The technique consists of internal plating combined with cortical strut allograft fixation. Materials and Methods: We prospectively followed nine children (five boys, four girls) with lower limb deformities due to type I OI, who had been treated with the bone splint technique (11 femurs, four tibias) between 2003 and 2006. The fracture healing time, deformity improvement, ambulation ability and complications were recorded to evaluate treatment effects. Results: At the time of surgery the average age in our study was 7.7 years (range 5-12 years). The average length of followup was 69 months (range 60-84 months). All patients had good fracture healing with an average healing time of 14 weeks (range 12-16 weeks) and none experienced further fractures, deformity, or nonunion. The fixation remained stable throughout the procedure in all cases, with no evidence of loosening or breakage of screws and the deformity and mobility significantly improved after surgery. Of the two children confined to bed before surgery, one was able to walk on crutches and the other needed a wheelchair. The other seven patients could walk without walking aids or support like crutches. Conclusions: These findings suggest that the bone splint technique provides good mechanical support and increases the bone mass. It is an effective treatment for children with OI and lower limb deformities. PMID:23960282

THIGH MUSCLE CROSS-SECTIONAL AREAS AND STRENGTH IN KNEES WITH EARLY VS KNEES WITHOUT RADIOGRAPHIC KNEE OSTEOARTHRITIS: A BETWEEN-KNEE, WITHIN-PERSON COMPARISON

PubMed Central

Ruhdorfer, AS; Dannhauer, T; Wirth, W; Cotofana, S; Roemer, F; Nevitt, M; Eckstein, F

2014-01-01

Objective To compare cross-sectional and longitudinal side-differences in thigh muscle anatomical cross-sectional areas (ACSAs), muscle strength, and specific strength (strength/ACSA), between knees with early radiographic change vs. knees without radiographic knee osteoarthritis (RKOA), in the same person. Design 55 (of 4796) Osteoarthritis Initiative participants fulfilled the inclusion criteria of early RKOA in one limb (definite tibiofemoral osteophytes; no radiographic joint space narrowing [JSN]) vs. no RKOA (no osteophyte; no JSN) in the contralateral limb. ACSAs of the thigh muscles and quadriceps heads were determined using axial MRIs at 33%/30% femoral length (distal to proximal). Isometric extensor and flexor muscle strength were measured (Good Strength Chair). Baseline quadriceps ACSA and extensor (specific) strength represented the primary analytic focus, and two-year changes of quadriceps ACSAs the secondary focus. Results No statistically significant side-differences in quadriceps (or other thigh muscle) ACSAs, muscle strength, or specific strength were observed between early RKOA vs. contralateral limbs without RKOA (p≥0.44), neither in men nor in women. The two-year reduction in quadriceps ACSA in limbs with early RKOA was −0.9±6% (mean ± standard deviation) vs. −0.5±6% in limbs without RKOA (statistical difference p=0.85). Conclusion Our results do not provide evidence that early unilateral radiographic changes, i.e. presence of osteophytes, are associated with cross-sectional or longitudinal differences in quadriceps muscle status compared with contralateral knees without RKOA. At the stage of early unilateral RKOA there thus appears to be no clinical need for countervailing a potential dys-balance in quadriceps ACSAs and strength between both knees. PMID:25278072

Do measures of reactive balance control predict falls in people with stroke returning to the community?

PubMed

Mansfield, A; Wong, J S; McIlroy, W E; Biasin, L; Brunton, K; Bayley, M; Inness, E L

2015-12-01

To determine if reactive balance control measures predict falls after discharge from stroke rehabilitation. Prospective cohort study. Rehabilitation hospital and community. Independently ambulatory individuals with stroke who were discharged home after inpatient rehabilitation (n=95). Balance and gait measures were obtained from a clinical assessment at discharge from inpatient stroke rehabilitation. Measures of reactive balance control were obtained: (1) during quiet standing; (2) when walking; and (3) in response to large postural perturbations. Participants reported falls and activity levels up to 6 months post-discharge. Logistic and Poisson regressions were used to identify measures of reactive balance control that were related to falls post-discharge. Decreased paretic limb contribution to standing balance control [rate ratio 0.8, 95% confidence interval (CI) 0.7 to 1.0; P=0.011], reduced between-limb synchronisation of quiet standing balance control (rate ratio 0.9, 95% CI 0.8 to 0.9; P<0.0001), increased step length variability (rate ratio 1.4, 95% CI 1.2 to 1.7; P=0.0011) and inability to step with the blocked limb (rate ratio 1.2, 95% CI 1.0 to 1.3; P=0.013) were significantly associated with increased fall rates when controlling for age, stroke severity, functional balance and daily walking activity. Impaired reactive balance control in standing and walking predicted increased risk of falls post-discharge from stroke rehabilitation. Specifically, measures that revealed the capacity of both limbs to respond to instability were related to increased risk of falls. These results suggest that post-stroke rehabilitation strategies for falls prevention should train responses to instability, and focus on remediating dyscontrol in the more-affected limb. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.