Science.gov

Sample records for joint surface injury

  1. Registration of knee joint surfaces for the in vivo study of joint injuries based on magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Cheng, Rita W. T.; Habib, Ayman F.; Frayne, Richard; Ronsky, Janet L.

    2006-03-01

    In-vivo quantitative assessments of joint conditions and health status can help to increase understanding of the pathology of osteoarthritis, a degenerative joint disease that affects a large population each year. Magnetic resonance imaging (MRI) provides a non-invasive and accurate means to assess and monitor joint properties, and has become widely used for diagnosis and biomechanics studies. Quantitative analyses and comparisons of MR datasets require accurate alignment of anatomical structures, thus image registration becomes a necessary procedure for these applications. This research focuses on developing a registration technique for MR knee joint surfaces to allow quantitative study of joint injuries and health status. It introduces a novel idea of translating techniques originally developed for geographic data in the field of photogrammetry and remote sensing to register 3D MR data. The proposed algorithm works with surfaces that are represented by randomly distributed points with no requirement of known correspondences. The algorithm performs matching locally by identifying corresponding surface elements, and solves for the transformation parameters relating the surfaces by minimizing normal distances between them. This technique was used in three applications to: 1) register temporal MR data to verify the feasibility of the algorithm to help monitor diseases, 2) quantify patellar movement with respect to the femur based on the transformation parameters, and 3) quantify changes in contact area locations between the patellar and femoral cartilage at different knee flexion angles. The results indicate accurate registration and the proposed algorithm can be applied for in-vivo study of joint injuries with MRI.

  2. Distal radioulnar joint injuries

    PubMed Central

    Thomas, Binu P; Sreekanth, Raveendran

    2012-01-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  3. Acromioclavicular and sternoclavicular joint injuries.

    PubMed

    Macdonald, Peter B; Lapointe, Pierre

    2008-10-01

    Acromioclavicular (AC) joint injuries are a frequent diagnosis following an acute shoulder injury. The literature on AC joint dislocation is extensive, reflecting the intense debate surrounding the topic. The choice of treatment is influenced by factors including the type of injury, the patient's occupation, the patient's past medical history, the acuity of the injury, and patient expectations. Sternoclavicular (SC) joint dislocation is an uncommon injury. The treatment of acute anterior SC joint dislocations is controversial. It is difficult to study with a well-designed prospective study because of the low frequency of this injury. Posterior dislocations are much less common than anterior dislocations. Posterior dislocations, however, are more serious; they are associated with significant complications and require prompt attention.

  4. [Injuries of the elbow joint].

    PubMed

    Lill, H; Voigt, C

    2004-10-01

    Injuries of the elbow joint increase along with increased athletic activity and life expectancy. Knowledge of anatomy and biomechanics is important for understanding injury patterns, specific diagnosis, and therapy. Here we classify the most frequent elbow injuries such as dislocation, ligamentous instability, and fracture of the radial head, processus coronoideus, olecranon, and distal humerus based on joint anatomy, biomechanics, clinical examination, and imaging. Specific therapies are described.

  5. Osteoligamentous injuries of the medial ankle joint.

    PubMed

    Lötscher, P; Lang, T H; Zwicky, L; Hintermann, B; Knupp, M

    2015-12-01

    Injuries of the ankle joint have a high incidence in daily life and sports, thus, playing an important socioeconomic role. Therefore, proper diagnosis and adequate treatment are mandatory. While most of the ligament injuries around the ankle joint are treated conservatively, great controversy exists on how to treat deltoid ligament injuries in ankle fractures. Missed injuries and inadequate treatment of the medial ankle lead to inferior outcome with instability, progressive deformity, and ankle joint osteoarthritis.

  6. Joint and long-bone gunshot injuries.

    PubMed

    Dougherty, Paul J; Vaidya, Rahul; Silverton, Craig D; Bartlett, Craig S; Najibi, Soheil

    2010-01-01

    Gunshot wounds remain a major clinical problem, with the number of nonfatal gunshot wounds reported as 60,000 to 80,000 per year in the United States. Bone or joint injuries comprise a major portion of gunshot wound injuries. It is paramount for orthopaedic surgeons to be thorough in their treatment of patients with these injuries. Intra-articular injuries remain a source of significant clinical morbidity because of joint stiffness, arthritis, and the risk of infection. Treatment of long-bone fractures is a challenging clinical problem, and further studies are needed to investigate modern treatment methods. Lead toxicity is a potential risk for patients with gunshot injuries, particular for those with joint injuries. The clinician's recognition of the signs and symptoms of lead toxicity is important to achieve the best care for these patients.

  7. Temporomandibular joint dysfunction following shotgun injury.

    PubMed

    Taglialatela Scafati, C; Taglialatela Scafati, S; Gargiulo, M; Cassese, M; Parascandolo, S

    2008-04-01

    Shotgun injuries to the maxillofacial region may have minor or, more often, devastating consequences. The most important factor in determining the extent of injury is the distance of the victim from the muzzle of the gun: usually, the longer the distance, the less severe the damage. Here is reported a case of shotgun injury sustained from a distance of approximately 10 m in which the deeper penetration of a single lead pellet led to significant involvement of the temporomandibular joint.

  8. [Chronic sports injuries of the knee joint].

    PubMed

    Mannil, M; Andreisek, G; Weishaupt, D; Fischer, M A

    2016-05-01

    Chronic sports injuries of the knee joint are common and mainly caused by repetitive (micro) trauma and exertion. Chronic insertion tendinopathies and avulsion fractures and symptoms related to entrapment, friction and impingement can be pathophysiologically distinguished in athletes. In this review, we depict the characteristic magnetic resonance imaging (MRI) findings of the most commonly occurring pathologies.

  9. Injury Criteria for Dynamic Hyperextension of the Female Elbow Joint

    DTIC Science & Technology

    2006-11-01

    1 INJURY CRITERIA FOR DYNAMIC HYPEREXTENSION OF THE FEMALE ELBOW JOINT Stefan M. Duma*, Gail A. Hansen, Eric A. Kennedy, Joel D. Stitzel...Laboratory Fort Rucker, AL 36362 ABSTRACT This paper describes an analysis to develop dynamic hyperextension injury criteria for the female elbow ...joint. Dynamic hyperextension tests were performed on 24 female cadaver elbow joints. The energy source was a drop tower utilizing a three-point

  10. [Vascular injuries in joint replacement surgery].

    PubMed

    Novotný, K; Pádr, R; Landor, I; Sosna, A

    2011-01-01

    Iatrogenic injuries to blood vessels in joint replacement surgery are rare events that occur as few per thousand. However, their sequelae are serious. The patient may either bleed to death, because vascular injury is not obvious and therefore difficult to diagnose, or lose the limb due to ischaemia. The highest risk of vascular injury is associated with repeat surgery and loosening of the acetabular component. We distinguish sharp and blunt force injuries. The former are caused by implants, sharp instruments, bone fragments or bone cement debris. The latter arise from stretching over a part of implanted material. Bleeding can be inapparent or apparent. Inapparent bleeding is difficult to diagnose and is recognized from the dynamics of blood losses. Haemodynamic instability or, in a worse case, even hypovolaemic shock may be the only signs of bleeding. Occlusion of an artery is manifested by limb ischaemia. The seriousness and progression of ischaemia depends on the rate of arterial occlusion, potential pathways for collateral circulation and the degree of atherosclerotic vascular disease. The patient with conduction anaesthesia does not feel pain and therefore the diagnosis must primarily be based on arterial pulsation in the limb and its skin colour. A pseudoaneurysm can develop due to a partially weakened vascular wall and its rupture is a life-threatening complication. Its presence is recognized as a pulsating mass in the groin. An arterio- venous fistula which arises from traumatic communication between the two vessels may lead to cardiac failure. The diagnosis is based on examination by sonography and digital subtraction angiography. The results of CT angiography and MR angiography are difficult to evaluate because of the presence of metal implants. In apparent bleeding it is sometimes difficult to locate the source. It is recommended to perform digital compression and gain access to the vessels from the extraperitoneal approach. When an expanding haematoma or

  11. Ulnopalmar dislocation of the fifth carpometacarpal joint. A rare injury.

    PubMed

    Fischer, J W; Waseem, M; Gambhir, A; Creedon, R J

    2002-04-01

    Volar dislocation of the carpometacarpal joint of the little finger is an uncommon injury. It is subdivided in ulnopalmar and radiopalmar dislocations. The injury can easily be missed on standard x-rays. Closed reduction and K-wire fixation has commonly been used in the treatment, although closed reduction and casting has been reported. Only 10 cases of an ulnopalmar dislocation were published previously. We report a case of a simultaneous dislocation of the 4th metacarpophalangeal joint and an ulnopalmar dislocation of the 5th carpometacarpal joint. The combination of these injuries has not been reported yet. We review the available literature and discuss the methods of treatment.

  12. Inflammation in Joint Injury and Post-Traumatic Osteoarthritis

    PubMed Central

    Lieberthal, Jason; Sambamurthy, Nisha; Scanzello, Carla R.

    2015-01-01

    Inflammation is a variable feature of osteoarthritis (OA), associated with joint symptoms and progression of disease. Signs of inflammation can be observed in joint fluids and tissues from patients with joint injuries at risk for development of post-traumatic osteoarthritis (PTOA). Furthermore, inflammatory mechanisms are hypothesized to contribute to the risk of OA development and progression after injury. Animal models of PTOA have been instrumental in understanding factors and mechanisms involved in chronic progressive cartilage degradation observed after a predisposing injury. Specific aspects of inflammation observed in humans, including cytokine and chemokine production, synovial reaction, cellular infiltration and inflammatory pathway activation, are also observed in models of PTOA. Many of these models are now being utilized to understand the impact of post-injury inflammatory response on PTOA development and progression, including risk of progressive cartilage degeneration and development of chronic symptoms post-injury. As evidenced from these models, a vigorous inflammatory response occurs very early after joint injury but is then sustained at a lower level at the later phases. This early inflammatory response contributes to the development of PTOA features including cartilage erosion and is potentially modifiable, but specific mediators may also play a role in tissue repair. Although the optimal approach and timing of anti-inflammatory interventions after joint injury are yet to be determined, this body of work should provide hope for the future of disease modification tin PTOA. PMID:26521728

  13. [Lateral ligament injuries of the ankle joint].

    PubMed

    Walther, M; Kriegelstein, S; Altenberger, S; Volkering, C; Röser, A; Wölfel, R

    2013-09-01

    Lateral ligament injuries are the most common sports injury and have a high incidence even in non-sportive activities. Although lateral ligament injuries are very common there is still a controversial debate on the best management. The diagnosis is based on clinical examination and X-ray images help to rule out fractures. Further imaging, especially magnetic resonance imaging (MRI) is used to diagnose associated injuries. According to the recommendations of the various scientific societies the primary therapy of lateral ligament injuries is conservative. Chronic ankle instability develops in 10-20 % of patients and the instability can be a result of sensomotoric deficits or insufficient healing of the lateral ligament complex. If the patient does not respond to an intensive rehabilitation program an operative reconstruction of the lateral ligaments has to be considered. Most of the procedures currently performed are anatomical reconstructions due to better long-term results compared to tenodesis procedures.

  14. Correlations Between General Joint Hypermobility and Joint Hypermobility Syndrome and Injury in Contemporary Dance Students.

    PubMed

    Ruemper, Alia; Watkins, Katherine

    2012-12-01

    The first objective of this study was to ascertain the prevalence of general joint hypermobility (GJH) and joint hypermobility syndrome (JHS) in BA Dance Theatre 1st and 3rd year students at a contemporary dance conservatory. The second objective was to determine the statistical correlation between GJH, JHS, and injury in this population. A total of 85 (female, N = 78; male, N = 7) contemporary dance students participated in the study. The Beighton score (with a forward flexion test modification) was used to determine GJH, and the Brighton criteria were used to verify JHS. Participants completed a self-reported injury questionnaire that included type of injury (physical complaint, medical diagnosis, or time-loss) and injury frequency. Statistical analysis (Pearson correlation) was used to correlate GJH, JHS, and frequency-of-injury scores. Overall, 69% of the students were found to have GJH, and 33% had JHS. A statistical correlation of r = + 0.331 (p < 0.01) was found between JHS and injury. No significant correlation was found between GJH and injury. This is the first study to look at these correlations in contemporary dance students and suggests that screening programs should include the Brighton criteria to identify JHS in these dancers. Subsequent injury tracking and injury prevention programs would then provide data for further research in this area.

  15. Acromioclavicular joint dislocation with associated brachial plexus injury

    PubMed Central

    Gallagher, Charles Alexander; Blakeney, William; Zellweger, René

    2014-01-01

    We present the case of a 32-year-old female who sustained a left acromioclavicular (AC) joint type V injury and brachial plexus injury. The patient's AC joint injury was identified 6 days after she was involved in a motorbike accident where she sustained multiple other injuries. She required operative fixation of the AC joint using a locking compression medial proximal tibial plate. At 3 months post operatively, the patient was found to have a subluxed left shoulder as a result of an axonal injury to the upper trunk of the brachial plexus. In addition, the tibial plate had cut out. The plate was subsequently removed. At 8 months the glenohumeral articulation had been restored and the patient had clinically regained significant shoulder function. After 15 months the patient was pain free and could complete all her activities of daily living without impediment. She returned to playing competitive pool after 24 months. PMID:24855076

  16. Knee Joint Dysfunctions That Influence Gait in Cerebrovascular Injury

    PubMed Central

    Lucareli, Paulo Roberto Garcia; Greve, Julia Maria D’Andrea

    2008-01-01

    INTRODUCTION There is still no consensus among different specialists on the subject of kinematic variation during the hemiparetic gait, including the main changes that take place during the gait cycle and whether the gait velocity changes the patterns of joint mobility. One of the most frequently discussed joints is the knee. OBJECTIVES This study aims to evaluate the variables found in the angular kinematics of knee joint, and to describe the alterations found in the hemiparetic gait resulting from cerebrovascular injury. METHODS This study included 66 adult patients of both genders with a diagnosis of either right or left hemiparesis resulting from ischemic cerebrovascular injury. All the participants underwent three-dimensional gait evaluation, an the angular kinematics of the joint knee were selected for analysis. RESULTS The results were distributed into four groups formed based on the median of the gait speed and the side of hemiparesis. CONCLUSIONS The relevant clinical characteristics included the important mechanisms of loading response in the stance, knee hyperextension in single stance, and reduction of the peak flexion and movement amplitude of the knee in the swing phase. These mechanisms should be taken into account when choosing the best treatment. We believe that the findings presented here may aid in preventing the occurrence of the problems found, and also in identifying the origin of these problems. PMID:18719753

  17. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2014-10-01

    Joint Injury and Subsequent Post- Traumatic Arthritis PRINCIPAL INVESTIGATOR: Steven A. Olson CONTRACTING ORGANIZATION: Duke...COVERED 30 Sep 2013 - 29 Sep 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Assessment of Biomarkers Associated with Joint Injury and Subsequent...the development of post-traumatic arthritis (PTA). PTA is a clinically important complication of joint injury with life-long effects for the

  18. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a...

  19. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a...

  20. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a...

  1. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a...

  2. 30 CFR 18.33 - Finish of surface joints.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Finish of surface joints. 18.33 Section 18.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a...

  3. Lower extremity joint position sense in runners with and without a history of knee overuse injury.

    PubMed

    Foch, Eric; Milner, Clare E

    2012-07-01

    Kinematic and kinetic analyses are routinely implemented to determine if gait differences exist between runners with and without a history of knee injury. Hip and knee kinematic differences have been reported between knee injured and non-injured runners. Yet, there is no consensus on whether these differences are the primary variables contributing to knee injury. Furthermore, there may be additional underlying factors that contribute to the development of injury that cannot be determined by gait analysis. The purpose of this investigation was to determine if joint position sense differences exist in runners with and without a history of knee overuse injury. Sagittal plane knee and hip joint position sense was measured in 13 runners with a history of knee overuse injury and 13 runners with no history of knee overuse injury. Absolute joint position replication error was measured during both a weight bearing and a non-weight bearing condition. Joint position replication errors at each joint were compared among groups and task using a two-way ANOVA with joint task as the repeated measure. Knee and hip joint replication errors were similar between both groups. The weight bearing and non-weight bearing tasks resulted in similar joint position replication errors. There were no interaction effects. In conclusion, knee flexion and hip adduction joint position sense is similar in runners with and without a history of knee overuse injury. Therefore, joint position sense measured via weight bearing and non-weight bearing joint position replication tasks may not play an important role in the development of knee overuse injury.

  4. Generalized Joint Laxity and Ligament Injuries in High School–Aged Female Volleyball Players in Japan

    PubMed Central

    Sueyoshi, Ted; Emoto, Gen; Yuasa, Tomoki

    2016-01-01

    Background: Generalized joint laxity has been linked to ligamentous injuries such as anterior cruciate ligament tear and ankle sprain. Purpose/Hypothesis: The purpose of this study was to investigate generalized joint laxity and incidence of ligament injuries in high school–aged female volleyball players. It was hypothesized that volleyball players with a past history of sprains would have increased generalized joint laxity compared with those without any history and that athletes with multiple sprains would demonstrate with a higher generalized joint laxity score than those who had only 1 sprain. Study Design: Case-control study; Level of evidence, 3. Methods: Forty-seven subjects were tested for generalized joint laxity using the Beighton and Horan Joint Mobility Index (BHJMI). They were categorized into 2 groups based on the presence of past ligament injury: injury group (IG) and noninjury group (NG). The IG group was further divided into 2 groups based on whether they had a single ligamentous injury (IGS) or multiple injuries (IGM) in the past to study whether there was any difference in scores between the subgroups. The collected data were analyzed statistically with 1-way analysis of variance. Results: Subjects in the IG group scored significantly higher on the BHJMI than those in the NG group. The mean score for the IG group was 2.40 ± 1.42, as opposed to 1.24 ± 1.09 for the NG group (P = .006). Eleven subjects in the IG group had suffered multiple injuries or recurrent injuries (IGM) and scored significantly higher than the remaining 19 individuals in the IG group, who had only sustained a single injury (IGS). The mean BHJMI scores were 3.18 ± 1.47 and 1.95 ± 1.22 for IGM and IGS, respectively (P = .02). Conclusion: Female athletes with a high generalized joint laxity score may be more prone to ligament injury and potentially to recurrent ligament injuries. PMID:27761474

  5. Contractures in burn injury part II: investigating joints of the hand.

    PubMed

    Schneider, Jeffrey C; Holavanahalli, Radha; Helm, Phala; O'Neil, Carina; Goldstein, Richard; Kowalske, Karen

    2008-01-01

    This study prospectively examines the incidence and severity of hand contractures after burn injury and determines predictors of contracture development. Data were collected prospectively from 1993 to 2002 for adult burn survivors admitted to a regional burn center. Demographic and medical data were collected on each subject. Primary outcome measures include presence of contractures, number of contractures, and the severity of contractures at each of the hand joints at hospital discharge. The metacarpal-phalangeal, proximal inter-phalangeal (PIP), and distal inter-phalangeal joints of all digits and the wrist joints are included in this study. Regression analysis was performed to determine predictors of the presence, severity, and number of contractures. Of the 985 study patients, 23% demonstrated at least one hand contracture at hospital discharge. Those with a contracture averaged ten contractures per person. Most contractures were mild (48%) or moderate (41%) in severity. The wrist was the most frequently affected joint (22%). Statistically significant predictors of contracture development include concomitant medical problems, total body surface area grafted and presence of hand burn and hand grafting (P < .05). Predictors of the number of contractures include length of stay, concomitant medical problems, burn size and presence of hand burn and grafting (P < .05). Contractures of the hand are a significant complication of burn injury. Clinicians can use the contracture predictors to help target interventions for those patients most at risk of developing hand contractures. Given the functional importance of the hand in daily living, the burn care community is challenged to find new ways of preventing and treating hand contractures.

  6. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury

    PubMed Central

    Wellsandt, Elizabeth; Gardinier, Emily S.; Manal, Kurt; Axe, Michael J.; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Background Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Hypothesis Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Study Design Case-control study; Level of evidence, 3. Methods Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Results Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs −0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: −0.001 ± 0.032 N·m·s/kg·m [nonOA] vs −0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs −0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak

  7. Turf-toe: a shoe-surface related football injury.

    PubMed

    Bowers, K D; Martin, R B

    1976-01-01

    Plantar capsule-ligament sprain of the great toe metatarsophalangeal joint, herein referred to as "turf-toe," is discussed with emphasis on two apparantly predisposing factors, playing surface hardness and shoe stiffness. Surface hardness studies have previously been performed by the authors on natural grass and AstroTurf. A study of football shoe flexibility is presented and the results correlated with the occurrence of turftoe. We have not encountered this entity in players wearing relatively stiff conventional seven posted football shoes or the more flexible soccer style shoe on natural grass fields. We have found it to be a not uncommon injury among players wearning the soccer style shoe on AstroTurf.

  8. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2014-10-01

    Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) "Assessment of Biomarkers Associated with Joint Injury and Subsequent Post...Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) 1. INTRODUCTION...Associated with Joint Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and

  9. Bilateral sacroiliac joint dislocation (anterior and posterior) with triradiate cartilage injury: a case report.

    PubMed

    Lee, Dae-Hee; Jeong, Woong-Kyo; Inna, Prashanth; Noh, Won; Lee, Dong-Ki; Lee, Soon-Hyuck

    2011-12-01

    Pediatric sacroiliac joint injuries are uncommon. Significant pelvis ring disruptions in children are rare, and their management is complicated by patient size, differences in bony architecture, and future growth and remodeling potential. We present a rare case of anterior sacroiliac joint dislocation associated with triradiate cartilage injury with a posterior sacroiliac dislocation on the contralateral side. This appears to be the first such case reported in the literature.

  10. Treatment of soft tissue injuries to the dorsum of the metacarpophalangeal joint (Boxer's knuckle).

    PubMed

    Arai, K; Toh, S; Nakahara, K; Nishikawa, S; Harata, S

    2002-02-01

    We retrospectively reviewed the surgical treatment for 16 cases of traumatic soft tissue injury to the metacarpophalangeal joint (Boxer's knuckle). A history of trauma was present in all cases and there was an associated extensor tendon dislocation in seven cases. Eight cases were initially treated conservatively, but their symptoms persisted. Intraoperative findings included rupture of the extensor hood or joint capsule in all cases. Surgical closure of the rupture of the joint capsule resulted in a successful outcome in all cases. We consider that conservative treatment of this injury may not be effective when the joint capsule of the metacarpophalangeal joint is ruptured. We recommend arthrography of the metacarpophalangeal joint to assist in the decision as to whether to proceed with surgical or conservative treatment.

  11. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2013-10-01

    with knee joint fractures will be enrolled, and we will collect serum, urine, and synovial fluid early after injury. Radiographic imaging will be...response to knee joint fracture will allow assessment of the potential use of the mouse model to evaluate future therapies to prevent PTA. 15...articular fractures requiring operative treatment. Patients with knee joint fractures will be enrolled, and we will collect serum, urine, and synovial

  12. Sock systems to prevent foot blisters and the impact on overuse injuries of the knee joint.

    PubMed

    Van Tiggelen, Damien; Wickes, Simon; Coorevits, Pascal; Dumalin, Mich; Witvrouw, Erik

    2009-02-01

    The incidence of foot blisters and other overuse injuries of the lower limb is very high during basic military training (BMT). One hundred and eighty-nine subjects were divided into two intervention groups wearing alternative sock systems and one control group. Overall, 57% of the 173 recruits who completed the training, developed foot blisters. Binary logistic regression revealed the type of sock, race, previous hiking or military experience, and known orthopedic foot conditions to be predictive variables for foot blisters. Fifty-three percent of the 173 recruits also developed another overuse injury of the lower limb (25.4% related to the knee joint). Previous military or hiking experience and the association of foot blisters revealed to be predictive for the overuse injuries of the knee joint. The results of the present study suggest associated foot blisters are also an important factor in the development of overuse injuries of the knee joint during BMT.

  13. Soluble Flt-1 improves the repair of ankle joint injury in rats

    PubMed Central

    Tian, Jing; Xie, Bing; Xiang, Liangbi; Zhao, Yong; Zhou, Dapeng

    2016-01-01

    The ankle injuries create great pain to a great number of patients worldwide. Past studies have focused on the development of practical treatments to relieve pain and improve recovery, but the molecular mechanisms underlying the ankle injuries, especially the local inflammation in the damaged ankle joint, have been rarely studied. Moreover, although reduction of production and secretion of pro-inflammatory cytokines may reduce the pain and promote the recovery, a practical approach is currently lacking. Here, we detected significantly higher levels of placental growth factor (PLGF) and pro-inflammatory cytokines in the joint fluid from the patients of acute ankle joint injury (AAJI). Interestingly, the levels of PLGF and pro-inflammatory cytokines in the joint fluid strongly correlated. In order to examine whether PLGF may regulate the production and secretion of pro-inflammatory cytokines in the injured joint, we used a rat carrageenan-induced ankle injury model for AAJI in humans. We injected soluble Flt-1 (sFlt-1) into the articular cavity of the injured ankle joint to block PLGF signaling and found that injection of sFlt-1 significantly improved the rat behavior in activity wheels test, which appeared to result from reduced secretion of the pro-inflammatory cytokines in the ankle joint. Thus, our study suggests that blocking PLGF signaling may be a novel therapeutic approach for treating AAJI in humans. PMID:27904694

  14. A review of synthetic playing surfaces, the shoe-surface interface, and lower extremity injuries in athletes.

    PubMed

    Taylor, Samuel A; Fabricant, Peter D; Khair, M Michael; Haleem, Amgad M; Drakos, Mark C

    2012-11-01

    The evolution of synthetic playing surfaces began in the 1960s and has had an impact on field use, shoe-surface dynamics, and the incidence of sports-related injuries. Modern third-generation turfs are being installed in recreational facilities and professional stadiums worldwide. Currently, > two-thirds of National Football League teams, > 100 National Collegiate Athletic Association Division I football teams, and > 1000 high schools in the United States have installed synthetic playing surfaces. Those in favor of such playing surfaces note their unique combination of versatility and durability; they can be used in both ideal and inclement weather conditions. However, the more widespread installation and use of these surfaces have raised questions and concerns regarding the impact of artificial turf on the type and severity of sports-related injuries. There appears to be no question that the shoe-surface interface has a significant impact on such injuries. Independent variables such as weather conditions, contact versus noncontact sport, shoe design, and field wear complicate many of the results reported in the literature, thereby preventing an accurate assessment of the true risk(s) associated with certain shoe-surface combinations. Historically, studies suggest that artificial turf is associated with a higher incidence of injury. Furthermore, reliable biomechanical data suggest that both the torque and strain experienced by lower extremity joints generated by artificial surfaces may be more than those generated by natural grass fields. Recent data from the National Football League support this theory and suggest that elite athletes may sustain more injuries, even when playing on the newer artificial surfaces. By contrast, some reports based on data collected from lower-level athletes suggest that artificial turf may protect against injury. This review discusses the history of artificial surfaces, the biomechanics of the shoe-surface interface, and some common

  15. [The relationship between whiplash injury and temporomandibular joint dysfunction].

    PubMed

    Barak, Shlomo

    2013-10-01

    This article aims to discuss the possible relationship between rapid extension-flexion of the neck-whiplash injury and temporomandibular disorders (TMD). Clinical experience and studies revealed that whiplash injury may cause TMD. The pathophysiology of TMD is described as well as clinical and imaging diagnostic criteria. The treatment modalities for TMD are: physiotherapy, nonsteroidal anti-inflammatory drugs and occlusal splints.

  16. Spinal neuronal plasticity is evident within 1 day after a painful cervical facet joint injury.

    PubMed

    Crosby, Nathan D; Weisshaar, Christine L; Winkelstein, Beth A

    2013-05-10

    Excessive stretch of the cervical facet capsular ligament induces persistent pain and spinal plasticity at later time points. Yet, it is not known when such spinal modifications are initiated following this painful injury. This study investigates the development of hyperalgesia and neuronal hyperexcitability in the spinal cord after a facet joint injury. Behavioral sensitivity was measured in a model of painful C6/C7 facet joint injury in the rat, and neuronal hyperexcitability in the spinal cord was evaluated at 6h and 1 day after injury or a sham procedure, in separate groups. Extracellular recordings of C6/C7 dorsal horn neuronal activity (229 neurons) were used to quantify spontaneous and evoked firing. Rats exhibited no change in sensitivity to mechanical stimulation of the forepaw at 6h, but did exhibit increased sensitivity at 1 day after injury (p=0.012). At 6h, both spontaneous neuronal activity and firing evoked by light brushing, pinch, and von Frey filaments (1.4-26g) applied at the forepaw were not different between sham and injury. At 1 day, spontaneous firing was noted in a greater number of neurons after injury than sham (p<0.04). Evoked firing was also increased 1 day after injury compared to normal and sham (p<0.03). Dorsal horn hyperexcitability and increased spontaneous firing developed between 6 and 24h after painful facet injury, suggesting that the development of hyperalgesia parallels dorsal horn hyperexcitability following mechanical facet joint injury, and these spinal mechanisms are initiated as early as 1 day after injury.

  17. Injuries and disorders among young ice skaters: relationship with generalized joint laxity and tightness.

    PubMed

    Okamura, Shinobu; Wada, Naoki; Tazawa, Masayuki; Sohmiya, Makoto; Ibe, Yoko; Shimizu, Toru; Usuda, Shigeru; Shirakura, Kenji

    2014-01-01

    This study retrospectively investigated 192 teenage speed and figure skaters with prior injuries documented by an athletes' questionnaire, who underwent a physical examination to assess their muscle tightness and generalized joint laxity. In all athletes, the degree of muscle tightness and joint laxity were measured by a standardized physical examination. A descriptive report of the types of injuries showed a predominance of fractures, ligament injuries, enthesitis, and lower back pain. Approximately 5% of all skaters tested positive for tightness, while 25.8% of figure skaters and 15.2% of speed skaters had generalized ligamentous laxity. Statistical testing showed an association between ankle sprains and muscle tightness, and an association between knee enthesitis and muscle tightness in skating athletes. There was also an association between lower back pain and generalized joint laxity, which held true only for the male skaters.

  18. Injuries and disorders among young ice skaters: relationship with generalized joint laxity and tightness

    PubMed Central

    Okamura, Shinobu; Wada, Naoki; Tazawa, Masayuki; Sohmiya, Makoto; Ibe, Yoko; Shimizu, Toru; Usuda, Shigeru; Shirakura, Kenji

    2014-01-01

    This study retrospectively investigated 192 teenage speed and figure skaters with prior injuries documented by an athletes’ questionnaire, who underwent a physical examination to assess their muscle tightness and generalized joint laxity. In all athletes, the degree of muscle tightness and joint laxity were measured by a standardized physical examination. A descriptive report of the types of injuries showed a predominance of fractures, ligament injuries, enthesitis, and lower back pain. Approximately 5% of all skaters tested positive for tightness, while 25.8% of figure skaters and 15.2% of speed skaters had generalized ligamentous laxity. Statistical testing showed an association between ankle sprains and muscle tightness, and an association between knee enthesitis and muscle tightness in skating athletes. There was also an association between lower back pain and generalized joint laxity, which held true only for the male skaters. PMID:25177155

  19. Joint Global War on Terror (GWOT) Vascular Injury Study 2

    DTIC Science & Technology

    2015-02-01

    underway and we have developed the surveillance program design and identified Service Members who incurred vascular injury. To date, four research nurse ...Current study staff consists of a program manager and four research nurses . The GWOT 2 Wartime Vascular Injury Study is an ongoing effort; therefore, the... Nurse , 2-4 April 2014, poster presentation o Vascular discharge education and follow-up care subsequent to wartime vascular trauma; Presented in San

  20. Efficacy of stepwise application of orthosis and kinesiology tape for treating thumb metacarpophalangeal joint hyperextension injury

    PubMed Central

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-01-01

    [Purpose] The purpose of this study was to investigate on the effects of the stepwise application of orthosis and kinesiology tape on a patient with thumb metacarpophalangeal joint hyperextension injury. [Subject] The patient was a 43-year-old man with severe thumb MCP pain and extremely limited thumb movement. [Methods] Stepwise application of orthosis and kinesiology taping were performed for 3 weeks and 4 weeks, respectively. [Results] After stepwise treatment, the patient was able to power grip, precision pinch, turn a key, and hold a pen without pain. [Conclusion] Stepwise application of thumb orthosis and kinesiology tape is a safe and effective treatment for thumb MCP joint hyperextension injury. PMID:26355325

  1. Isolated radial volar dislocation of the fifth carpometacarpal joint :a rare injury

    PubMed Central

    El Kadi, Khalid Ibn; Sbiyaa, Mohcine; Alami, Badr; Rabhi, Ilyass; Marzouki, Amine; Lahrach, Kamal; Boutayeb, Fawzi

    2013-01-01

    Isolated palmar dislocation of the fifth carpometacarpal joint is an uncommon injury and classified as radio-palmar or ulno-palmar according to the direction of displacement of the fifth metacarpal base. This very rare injury is often difficult to recognize. A careful neurologic assessment of the patient is a necessity, as well as obtaining proper radiographs of the hand. The purpose of this report is to present a patient with a pure isolated volar dislocation of the fifth carpometacarpal joint that was satisfactorily treated with closed reduction and casting. A review of the literature is presented. PMID:24711880

  2. Efficacy of stepwise application of orthosis and kinesiology tape for treating thumb metacarpophalangeal joint hyperextension injury.

    PubMed

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-08-01

    [Purpose] The purpose of this study was to investigate on the effects of the stepwise application of orthosis and kinesiology tape on a patient with thumb metacarpophalangeal joint hyperextension injury. [Subject] The patient was a 43-year-old man with severe thumb MCP pain and extremely limited thumb movement. [Methods] Stepwise application of orthosis and kinesiology taping were performed for 3 weeks and 4 weeks, respectively. [Results] After stepwise treatment, the patient was able to power grip, precision pinch, turn a key, and hold a pen without pain. [Conclusion] Stepwise application of thumb orthosis and kinesiology tape is a safe and effective treatment for thumb MCP joint hyperextension injury.

  3. MR imaging of temporomandibular joint abnormalities associated with cervical hyperextension/hyperflexion (whiplash) injuries.

    PubMed

    Pressman, B D; Shellock, F G; Schames, J; Schames, M

    1992-01-01

    Patients often have temporomandibular joint (TMJ) dysfunction-related symptoms after cervical hyperextension/hyperflexion injuries ("whiplash") caused by rear-end motor-vehicle collisions. To determine abnormalities of the TMJ associated with these injuries, 33 consecutive symptomatic patients (66 joints) with no direct trauma to the jaw, mouth, head, or face due to the accident and no prior history of TMJ dysfunction underwent magnetic resonance (MR) imaging, and the images were retrospectively analyzed. Overall, 29 (88%) patients had some type of TMJ abnormality related to whiplash injury. Displacement of the disk was seen in 37 (56%) of the TMJs as follows: 21 (32%) had anterior displacement with reduction, nine (14%) had anterior displacement without reduction, six (9%) had lateral or medial displacement, and one (2%) had posterior displacement. On T2-weighted images, 43 (65%) TMJs had abnormal joint fluid or edema, predominantly affecting the joint capsule and/or lateral pterygoid muscles. The finding that many of the patients had joint fluid and/or soft-tissue edema indicates that T2-weighted images are especially useful for assessment of patients with a history of whiplash injury.

  4. Unusual exostosis formation of the subtalar joint following an inversion ankle injury.

    PubMed

    Cisco, R W; Shaffer, M; Kuchler, L

    1993-01-01

    Exostosis formation following trauma isnot uncommon to the joints of the foot and ankle. The etiology and treatment of these boney lesions is well-documented in the literature. The following is a report of an unusual exostosis of the subtalar joint following inversion ankle injury. This case is unusual in respect to the formation of an adventitious articulation, the size of the lesion, and the pathology.

  5. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2013-10-01

    blood, urine processed and stored in -80° freezer [FG, VBK] Task 4. Visual analog pain score, the Knee injury and Osteoarthritis Outcome Score (KOOS...series of murine experiments, both with the goal of identifying biomarkers that are associated with development of PTA. Patients with knee joint...articular fracture using two strains in which one strain develops PTA and the other does not. Comparison of the human and mouse response to knee joint

  6. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post Traumatic Arthritis

    DTIC Science & Technology

    2015-10-01

    Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK...of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak...2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) 1. INTRODUCTION: Post-traumatic arthritis (PTA) is a clinically

  7. Elbow joint stability following experimental osteoligamentous injury and reconstruction.

    PubMed

    Deutch, Søren R; Jensen, Steen L; Tyrdal, Stein; Olsen, Bo S; Sneppen, Otto

    2003-01-01

    Elbow joint dislocation was simulated in cadaveric specimens to quantify laxity induced by radial head and coronoid process lesions, either alone or in combination with collateral ligament insufficiency. The effects of lateral ligament reconstruction and radial head prosthesis replacement were also considered. Absence of the radial head and the coronoid process induced rotatory laxity of 145% and 128% (both P <.01), respectively, compared with the intact joint. When both were absent, the joints subluxated regardless of collateral ligament status. Isolated radial head prosthesis implantation prevented this subluxation, and laxity almost normalized. Lateral collateral ligament reconstruction prevented major laxity even in the absence of the radial head. Lateral collateral ligament reconstruction and radial head prosthetic replacement yielded restraint against gross instability in the maximal unstable situation (terrible triad). The lateral collateral ligament is the prime stabilizer to external rotation, and reconstruction of this alone, even with an absent radial head, is beneficial.

  8. Ankylosis of temporomandibular joint after the traumatic brain injury: a report of two cases.

    PubMed

    Meng, Qinggong; Li, Bo; Long, Xing; Li, Jian; Yan, Quanmei

    2013-08-01

    Mouth opening limitation after the neurosurgical procedures is a common complication and usually resolves within 3 months. If limited mouth opening remains unresolved on the long term, an intra-articular ankylosis of temporomandibular joint may develop eventually. The possible mechanisms base on the myositis and atrophy of the masticatory muscles for these craniotomies are often involved in the temporalis. This article reports two unusual cases with the intra-articular ankylosis of temporomandibular joint after the traumatic brain injury, who received a modified surgical treatment for joint ankylosis. Therefore, the early diagnosis and intervention are important to minimize these complications.

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

    PubMed

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

    2009-11-01

    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.

  10. Anterior Dislocation of Elbow Joint-Case Report of A Rare Injury

    PubMed Central

    Kumar, Rakesh; Sekhawat, Vishal; Sankhala, SS; Bijarnia, Isha

    2014-01-01

    Introduction: In view of the comparative frequency of posterior dislocations of the elbow, it is rather remarkable that anterior dislocations of that joint should be among the rarest of injuries. Authors report a case of acute anterior dislocation with old fracture of medial epicondyle. Case Report: 22 years old male presented with acute pain and tenderness with deformity of right elbow joint and inability to move the elbow joint after he fell down during an episode of seizure. There was no neurovascular deficit. Radiological examination confirmed anterior dislocation of elbow joint with an ununited medial epicondyle fracture. Elbow was reduced under general anesthesia in emergency operation theatre. Conclusion: Anterior dislocation of elbow is very rare. Early diagnosis and proper reduction of dislocation is key of normal functioning of elbow joint. PMID:27298973

  11. Case Series of First Metatarsophalangeal Joint Injuries in Division 1 College Athletes

    PubMed Central

    Faltus, John; Mullenix, Kerry; Moorman, Claude T.; Beatty, Kyle; Easley, Mark E.

    2014-01-01

    Context: Injuries of the first metatarsophalangeal (hallux MP) joint can be debilitating in the athletic population. Turf toe and plantar plate injuries are typically diagnosed similarly. However, variance in injury mechanism as well as compromised integrity of soft tissue and ligamentous structures make it difficult to accurately diagnose specific hallux MP injuries. Recent literature has supported the use of both radiographic imaging and the Lachman test as reliable indicators of joint instability in the presence of hallux MP injuries. To date, research supporting specific rehabilitation interventions and return-to-play decision making for hallux MP injuries has been limited to case studies and suggested guidelines from literature reviews. There is limited evidence suggesting specific criteria for surgical and nonsurgical decision making in conjunction with rehabilitation progressions to return an athlete to sport when managing hallux MP injuries. Evidence Acquisition: A literature search was performed using Medline, PubMed, and Google Scholar to find and review articles from 1970 to 2013 that addressed the basic anatomy of the plantar plate, injuries to this anatomical structure, and the evaluation, diagnosis, surgical and nonsurgical management, and rehabilitation of these injuries, specifically in the athletic population. Medical information for each case was gathered from electronic medical records from the individual athletes cited in this case series, which included imaging reports, rehabilitation documentation, and both evaluation and surgical reports. No statistical analysis was used. Study Design: Case series. Level of Evidence: Level 4. Results: Treatment plans for each case varied depending on surgical and nonsurgical intervention and rehabilitation outcomes. However, each athlete was able to return to sports-specific activities. Conclusion: Successful outcomes for hallux MP injuries are contingent on thorough evaluation, appropriate clinical decision

  12. Injury tolerance and moment response of the knee joint to combined valgus bending and shear loading.

    PubMed

    Bose, Dipan; Bhalla, Kavi S; Untaroiu, Costin D; Ivarsson, B Johan; Crandall, Jeff R; Hurwitz, Shepard

    2008-06-01

    Valgus bending and shearing of the knee have been identified as primary mechanisms of injuries in a lateral loading environment applicable to pedestrian-car collisions. Previous studies have reported on the structural response of the knee joint to pure valgus bending and lateral shearing, as well as the estimated injury thresholds for the knee bending angle and shear displacement based on experimental tests. However, epidemiological studies indicate that most knee injuries are due to the combined effects of bending and shear loading. Therefore, characterization of knee stiffness for combined loading and the associated injury tolerances is necessary for developing vehicle countermeasures to mitigate pedestrian injuries. Isolated knee joint specimens (n=40) from postmortem human subjects were tested in valgus bending at a loading rate representative of a pedestrian-car impact. The effect of lateral shear force combined with the bending moment on the stiffness response and the injury tolerances of the knee was concurrently evaluated. In addition to the knee moment-angle response, the bending angle and shear displacement corresponding to the first instance of primary ligament failure were determined in each test. The failure displacements were subsequently used to estimate an injury threshold function based on a simplified analytical model of the knee. The validity of the determined injury threshold function was subsequently verified using a finite element model. Post-test necropsy of the knees indicated medial collateral ligament injury consistent with the clinical injuries observed in pedestrian victims. The moment-angle response in valgus bending was determined at quasistatic and dynamic loading rates and compared to previously published test data. The peak bending moment values scaled to an average adult male showed no significant change with variation in the superimposed shear load. An injury threshold function for the knee in terms of bending angle and shear

  13. Cartilage Shear Kinematics During Tibio-Femoral Articulation: Effect of Acute Joint Injury & Tribosupplementation on Synovial Fluid Lubrication

    PubMed Central

    Wong, Benjamin L.; Kim, Seung Hyun Chris; Antonacci, Jennifer M.; McIlwraith, C. Wayne; Sah, Robert L.

    2009-01-01

    Objective To determine the effects of acute injury and tribosupplementation by hyaluronan (HA) on synovial fluid (SF) modulation of cartilage shear during tibio-femoral articulation. Methods Human osteochondral blocks from the lateral femoral condyle (LFC) and tibial plateau (LTP) were apposed, compressed 13%, and subjected to sliding under video microscopy. Tests were conducted with equine SF from normal joints (NL-SF), SF from acutely injured joints (AI-SF), and AI-SF to which HA was added (AI-SF+HA). Local and overall shear strain (Exz) and the lateral displacement (Δx) at which Exz reached 50% of peak values (Δx1/2) were determined. Results During articulation, LFC and LTP cartilage Exz increased with Δx and peaked when surfaces slid, with peak Exz being maintained during sliding. With AI-SF as lubricant, surface and overall Δx1/2 were ~40% and ~20% higher, respectively than values with NL-SF and AI-SF+HA as lubricant. Also, peak Exz was markedly higher with AI-SF as lubricant than with NL-SF as lubricant, both near the surface (~80%) and overall (50–200%). Following HA supplementation to AI-SF, Exz was reduced from values with AI-SF alone by 30–50% near the surface and 20–30% overall. Magnitudes of surface and overall Exz were markedly (~50–80%) higher in LTP cartilage than LFC cartilage for all lubricants. Conclusion Acute injury impairs SF function, elevating cartilage Exz markedly during tibio-femoral articulation; such elevated Exz may contribute to post-injury associated cartilage degeneration. Since HA partially restores the function of AI-SF, as indicated by Exz, tribosupplements may be beneficial in restoring cartilage mechanobiology. PMID:20004636

  14. Textured bearing surface in artificial joints to reduce macrophage activation

    NASA Astrophysics Data System (ADS)

    Nakanishi, Yoshitaka; Nishi, Naoki; Chikaura, Hiroto; Nakashima, Yuta; Miura, Hiromasa; Higaki, Hidehiko; Mizuta, Hiroshi; Iwamoto, Yukihide; Fujiwara, Yukio; Komohara, Yoshihiro; Takeya, Motohiro

    2015-12-01

    Micro slurry-jet erosion has been proposed as a precision machining technique for the bearing surfaces of artificial joints in order to reduce the total amount of polyethylene wear and to enlarge the size of the wear debris. The micro slurry-jet erosion method is a wet blasting technique which uses alumina particles as the abrasive medium along with compressed air and water to create an ideal surface. Pin-on-disc wear tests with multidirectional sliding motion on the textured surface of a \\text{Co}-\\text{Cr}-\\text{Mo} alloy counterface for polyethylene resulted in both a reduction of wear as well as enlargement of the polyethylene debris size. In this study, primary human peripheral blood mononuclear phagocytes were incubated with the debris, and it was elucidated that the wear debris generated on the textured surface regulated secretion of the proinflammatory cytokines IL-6 and TNF-α, indicating a reduction in the induced tissue reaction and joint loosening.

  15. Post-Traumatic Osteoarthritis in Mice Following Mechanical Injury to the Synovial Joint

    PubMed Central

    Rai, Muhammad Farooq; Duan, Xin; Quirk, James D.; Holguin, Nilsson; Schmidt, Eric J.; Chinzei, Nobuaki; Silva, Matthew J.; Sandell, Linda J.

    2017-01-01

    We investigated the spectrum of lesions characteristic of post-traumatic osteoarthritis (PTOA) across the knee joint in response to mechanical injury. We hypothesized that alteration in knee joint stability in mice reproduces molecular and structural features of PTOA that would suggest potential therapeutic targets in humans. The right knees of eight-week old male mice from two recombinant inbred lines (LGXSM-6 and LGXSM-33) were subjected to axial tibial compression. Three separate loading magnitudes were applied: 6N, 9N, and 12N. Left knees served as non-loaded controls. Mice were sacrificed at 5, 9, 14, 28, and 56 days post-loading and whole knee joint changes were assessed by histology, immunostaining, micro-CT, and magnetic resonance imaging. We observed that tibial compression disrupted joint stability by rupturing the anterior cruciate ligament (except for 6N) and instigated a cascade of temporal and topographical features of PTOA. These features included cartilage extracellular matrix loss without proteoglycan replacement, chondrocyte apoptosis at day 5, synovitis present at day 14, osteophytes, ectopic calcification, and meniscus pathology. These findings provide a plausible model and a whole-joint approach for how joint injury in humans leads to PTOA. Chondrocyte apoptosis, synovitis, and ectopic calcification appear to be targets for potential therapeutic intervention. PMID:28345597

  16. Automated inspection of solder joints for surface mount technology

    NASA Technical Reports Server (NTRS)

    Savage, Robert M.; Park, Hyun Soo; Fan, Mark S.

    1993-01-01

    Researchers at NASA/GSFC evaluated various automated inspection systems (AIS) technologies using test boards with known defects in surface mount solder joints. These boards were complex and included almost every type of surface mount device typical of critical assemblies used for space flight applications: X-ray radiography; X-ray laminography; Ultrasonic Imaging; Optical Imaging; Laser Imaging; and Infrared Inspection. Vendors, representative of the different technologies, inspected the test boards with their particular machine. The results of the evaluation showed limitations of AIS. Furthermore, none of the AIS technologies evaluated proved to meet all of the inspection criteria for use in high-reliability applications. It was found that certain inspection systems could supplement but not replace manual inspection for low-volume, high-reliability, surface mount solder joints.

  17. The Self-Injury Trauma (SIT) Scale: A Method for Quantifying Surface Tissue Damage Caused by Self-Injurious Behavior.

    ERIC Educational Resources Information Center

    Iwata, Brian A.; And Others

    1990-01-01

    A measure, the Self-Injury Trauma Scale, is described for classifying and quantifying surface tissue damage. The scale permits differentiation of self-injurious behavior according to topography, location of the injury on the body, type of injury, number of injuries, and estimate of severity. High interrater reliability has been found. (Author/DB)

  18. [Value of magnetic resonance imaging in the diagnosis of sequels of shoulder joint injuries].

    PubMed

    Murashina, I V; Egorova, E A

    2011-01-01

    The paper presents the results of examining 45 persons with sequels of shoulder joint injuries, by applying magnetic resonance imaging (MRI) (100%) and arthroscopy (95.6%). The data of arthroscopy were compared with those of MRI; thereafter the sensitivity, specificity, and accuracy of MRI were calculated. The findings suggested that there was no statistically significant difference in the capacities of the two comparable techniques MRI and arthroscopy to diagnose labral tears with degenerative changes, synovitis, bursitis and tendinitis (McNemar's test; p > 0.05). The capacities of MRI are greater than those of arthroscopy only to detect the structural disintegrity of the joint shoulder.

  19. Effects of Equine Joint Injury on Boundary Lubrication of Articular Cartilage by Synovial Fluid: Role of Hyaluronan

    PubMed Central

    Antonacci, Jennifer M.; Schmidt, Tannin A.; Serventi, Lisa A.; Cai, Matthew Z.; Shu, YuYu L.; Schumacher, Barbara L.; McIlwraith, C. Wayne; Sah, Robert L.

    2012-01-01

    Objective To compare equine synovial fluid (eSF) from post-injury and control joints for (1) cartilage boundary lubrication function, (2) putative boundary lubricant molecules hyaluronan (HA), proteoglycan-4 (PRG4), and surface-active phospholipids (SAPL), (3) relationships between lubrication function and composition, and (4) lubrication restoration by addition of HA. Methods eSF from normal (NL), acute injury (AI), and chronic injury (CI) joints were analyzed for boundary lubrication of normal articular cartilage as kinetic friction coefficient (μkinetic). eSF were also analyzed for HA, PRG4, and SAPL concentrations and HA molecular weight (MW) distribution. The effect of addition of HA, of different concentrations and MW, to AI- and NL-eSF samples on μkinetic was determined. Results The μkinetic of AI-eSF (0.036) was higher (+39%) than that of NL-eSF (0.026). Compared to NL-eSF, AI-eSF had a lower HA concentration (−30%) of lower MW forms, higher PRG4 concentration (+83%), and higher SAPL concentration (+144%). CI-eSF had μkinetic, HA, PRG4, and SAPL characteristics intermediate to that of AI-eSF and NL-eSF. Regression analysis revealed that μkinetic decreased with increasing HA concentration in eSF. The friction-reducing properties of HA alone improved with increasing concentration and MW. Addition of high-MW HA (4,000kDa) to AI-eSF reduced μkinetic to a value near that of NL-eSF. Conclusion In the acute post-injury stage, eSF exhibits poor boundary lubrication properties as indicated by a high μkinetic. HA of diminished concentration and MW may be the basis for this, and adding HA to deficient eSF restored lubrication function. PMID:22605527

  20. Joint inversion of surface and borehole magnetic amplitude data

    NASA Astrophysics Data System (ADS)

    Li, Zelin; Yao, Changli; Zheng, Yuanman; Yuan, Xiaoyu

    2016-04-01

    3D magnetic inversion for susceptibility distribution is a powerful tool in quantitative interpretation of magnetic data in mineral exploration. However, the inversion and interpretation of such data are faced with two problems. One problem is the poor imaging results of deep sources when only surface data are inverted. The other is the unknown total magnetization directions of sources when strong remanence exists. To deal with these problems simultaneously, we propose a method through the joint inversion of surface and borehole magnetic amplitude data. In this method, we first transform both surface and borehole magnetic data to magnetic amplitude data that are less sensitive to the directions of total magnetization, and then preform a joint inversion of the whole amplitude data to generate a 3D susceptibility distribution. The amplitude inversion algorithm uses Tikhonov regularization and imposes a positivity constraint on the effective susceptibility defined as the ratio of magnetization magnitude over the geomagnetic field strength. In addition, a distance-based weighting function is used to make the algorithm applicable to joint data sets. To solve this positivity-constraint inversion problem efficiently, an appropriate optimization method must be chosen. We first use an interior-point method to incorporate the positivity constraint into the total objective function, and then minimize the objective function via a Gauss-Newton method due to the nonlinearity introduced by the positivity constraint and the amplitude data. To further improve the efficiency of the inversion algorithm, we use a conjugate gradient method to carry out the fast matrix-vector multiplication during the minimization. To verify the utility of the proposed method, we invert the synthetic and field data using three inversion methods, including the joint inversion of surface and borehole three-component magnetic data, the inversion of surface magnetic amplitude data, and the proposed joint

  1. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2014-10-01

    Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) Table of Contents...Joint Injury and Subsequent Post-Traumatic Arthritis" Start date: 9/30/2012 PIs – Steven A. Olson ( SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK... SAO ); Farshid Guilak (FG); and Virginia B Kraus (VBK) 1. INTRODUCTION: Post-traumatic arthritis (PTA) is a clinically important complication of

  2. Rules to limp by: joint compensation conserves limb function after peripheral nerve injury.

    PubMed

    Bauman, Jay M; Chang, Young-Hui

    2013-10-23

    Locomotion persists across all manner of internal and external perturbations. The objective of this study was to identify locomotor compensation strategies in rodent models of peripheral nerve injury. We found that hip-to-toe limb length and limb angle was preferentially preserved over individual joint angles after permanent denervation of rat ankle extensor muscles. These findings promote further enquiry into the significance of limb-level function for neuromechanical control of legged locomotion.

  3. Development of Intra-Articular Drug Delivery to Alter Progression of Arthritis Following Joint Injury

    DTIC Science & Technology

    2012-04-01

    Arthritis Following Joint Injury Steven A. Olson, M.D. W81XWH-10-1-0890 Duke University Durham, NC 27705 15 September 2011 - 14 March ...4 Appendices – Abstract accepted for presentation at ORASI ( Osteoarthritis Research Society International) meeting in...NC 2Department of Biomedical Engineering, Duke University, Durham, NC PURPOSE: Post-traumatic arthritis (PTA) is a form of osteoarthritis (OA

  4. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2013-10-01

    blood, urine processed and stored in -80° freezer [FG, VBK] Task 4. Visual analog pain score, the Knee injury and Osteoarthritis Outcome Score...series of murine experiments, both with the goal of identifying biomarkers that are associated with development of PTA. Patients with knee joint...articular fracture using two strains in which one strain develops PTA and the other does not. Comparison of the human and mouse response to knee

  5. Development of a Lubricant Therapy to Prevent Development of Osteoarthritis after Acute Injury of Synovial Joints

    DTIC Science & Technology

    2015-10-01

    AD______________ AWARD NUMBER: W81XWH-14-1-0562 TITLE: Development of a Lubricant Therapy to Prevent Development of Osteoarthritis after Acute...Injury of Synovial Joints PRINCIPAL INVESTIGATOR: Robert L. Sah RECIPIENT: Dr. Prem Yadav, Ph.D. REPORT DATE: October 2015 TYPE OF REPORT...PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE October 2015 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2014 - 29 Sep 2015 4

  6. Alternate bearing surfaces in total joint arthroplasty: biologic considerations.

    PubMed

    Archibeck, M J; Jacobs, J J; Black, J

    2000-10-01

    The problem of periprosthetic osteolysis is currently the major limiting factor in joint arthroplasty longevity. Because this process has been shown to be primarily a biologic response to wear particles, corrosion products, or both, efforts to reduce particle generation are being undertaken. These efforts include the development of modified polyethylene and alternative articulating surfaces. These alternate bearing surfaces currently include ceramic-on-polyethylene, ceramic-on-ceramic, and metal-on-metal. Although these alternate bearings diminish or eliminate the generation of polyethylene particles, ceramic and metal particles are produced. The purpose of the current review is to discuss the literature that addresses the biologic response to these particles, locally and systemically.

  7. [UHMWPE - polyethylene for articulating surfaces of joint replacements].

    PubMed

    Pokorný, David; Sosna, Antonín; Šlouf, Miroslav; Fulín, Petr; Štefan, Jan; Landor, Ivan

    2016-01-01

    The introduction of artificial joint replacement constitutes a breakthrough method of treatment for severe joint disease for millions of people worldwide.Annual increase in the number of primary replacement and also increasing demands on the longevity of joint replacements are leading to increased demands on wear resistance of articular surface. Ultra-high molecular weight polyethylene (UHMWPE) is still most commonly used material for the production of articular surface. It was introduced into clinical practice in the 60s of the 20th century. Physical-chemical properties of UHMWPE are subject of many studies. These lead gradually to its improvement in terms of higher wear resistance while maintaining the stability against oxidative degradation.The main objective of this review is to summarize the basic properties of high-molecular weight polyethylene which are important for its use in orthopaedic practice and to explain the possibilities of its modification and sterilization. Knowledge of the latest trends about this material helps to orthopaedic surgeons get oriented in the issues and then to choose for their patients implants with the highest implant longevity.

  8. Joint power and kinematics coordination in load carriage running: Implications for performance and injury.

    PubMed

    Liew, Bernard X W; Morris, Susan; Netto, Kevin

    2016-06-01

    Investigating the impact of incremental load magnitude on running joint power and kinematics is important for understanding the energy cost burden and potential injury-causative mechanisms associated with load carriage. It was hypothesized that incremental load magnitude would result in phase-specific, joint power and kinematic changes within the stance phase of running, and that these relationships would vary at different running velocities. Thirty-one participants performed running while carrying three load magnitudes (0%, 10%, 20% body weight), at three velocities (3, 4, 5m/s). Lower limb trajectories and ground reaction forces were captured, and global optimization was used to derive the variables. The relationships between load magnitude and joint power and angle vectors, at each running velocity, were analyzed using Statistical Parametric Mapping Canonical Correlation Analysis. Incremental load magnitude was positively correlated to joint power in the second half of stance. Increasing load magnitude was also positively correlated with alterations in three dimensional ankle angles during mid-stance (4.0 and 5.0m/s), knee angles at mid-stance (at 5.0m/s), and hip angles during toe-off (at all velocities). Post hoc analyses indicated that at faster running velocities (4.0 and 5.0m/s), increasing load magnitude appeared to alter power contribution in a distal-to-proximal (ankle→hip) joint sequence from mid-stance to toe-off. In addition, kinematic changes due to increasing load influenced both sagittal and non-sagittal plane lower limb joint angles. This study provides a list of plausible factors that may influence running energy cost and injury risk during load carriage running.

  9. Military Exercises, Knee and Ankle Joint Position Sense, and Injury in Male Conscripts: A Pilot Study

    PubMed Central

    Mohammadi, Farshid; Azma, Kamran; Naseh, Iman; Emadifard, Reza; Etemadi, Yasaman

    2013-01-01

    Context: The high incidence of lower limb injuries associated with physical exercises in military conscripts suggests that fatigue may be a risk factor for injuries. Researchers have hypothesized that lower limb injuries may be related to altered ankle and knee joint position sense (JPS) due to fatigue. Objective: To evaluate if military exercises could alter JPS and to examine the possible relation of JPS to future lower extremity injuries in military service. Design: Cohort study. Setting: Laboratory. Patients or Other Participants: A total of 50 male conscripts (age = 21.4 ± 2.3 years, height = 174.5 ± 6.4 cm, mass = 73.1 ± 6.3 kg) from a unique military base were recruited randomly. Main Outcome Measure(s): Participants performed 8 weeks of physical activities at the beginning of a military course. In the first part of the study, we instructed participants to recognize predetermined positions before and after military exercises so we could examine the effects of military exercise on JPS. The averages of the absolute error and the variable error of 3 trials were recorded. We collected data on the frequency of lower extremity injuries over 8 weeks. Next, the participants were divided into 2 groups: injured and uninjured. Separate 2 × 2 × 2 (group-by-time-by-joint) mixed-model analyses of variance were used to determine main effects and interactions of these factors for each JPS measure. In the second part of the study, we examined whether the effects of fatigue on JPS were related to the development of injury during an 8-week training program. We calculated Hedges effect sizes for JPS changes postexercise in each group and compared change scores between groups. Results: We found group-by-time interactions for all JPS variables (F range = 2.86–4.05, P < .01). All participants showed increases in JPS errors postexercise (P < .01), but the injured group had greater changes for all the variables (P < .01). Conclusions: Military conscripts who sustained lower

  10. The Effect of Surface Irregularities on Wing Drag. II - Lap Joints. 2; Lap Joints

    NASA Technical Reports Server (NTRS)

    Hood, Manley J.

    1938-01-01

    Tests have been made in the NACA 8-foot high-speed wind tunnel of the drag caused by four types of lap joint. The tests were made on an airfoil of NACA 23012 section and 5-foot chord and covered in a range of speeds from 80 to 500 miles per hour and lift coefficients from 0 to 0.30. The increases in profile drag caused by representative arrangements of laps varied from 4 to 9%. When there were protruding rivet heads on the surface, the addition of laps increased the drag only slightly. Laps on the forward part of a wing increased the drag considerably more than those farther back.

  11. Development of an Arthroscopic Joint Capsule Injury Model in the Canine Shoulder

    PubMed Central

    Kovacevic, David; Baker, Andrew R.; Staugaitis, Susan M.; Kim, Myung-Sun; Ricchetti, Eric T.; Derwin, Kathleen A.

    2016-01-01

    Background The natural history of rotator cuff tears can be unfavorable as patients develop fatty infiltration and muscle atrophy that is often associated with a loss of muscle strength and shoulder function. To facilitate study of possible biologic mechanisms involved in early degenerative changes to rotator cuff muscle and tendon tissues, the objective of this study was to develop a joint capsule injury model in the canine shoulder using arthroscopy. Methods Arthroscopic surgical methods for performing a posterior joint capsulectomy in the canine shoulder were first defined in cadavers. Subsequently, one canine subject underwent bilateral shoulder joint capsulectomy using arthroscopy, arthroscopic surveillance at 2, 4 and 8 weeks, and gross and histologic examination of the joint at 10 weeks. Results The canine subject was weight-bearing within eight hours after index and follow-up surgeries and had no significant soft tissue swelling of the shoulder girdle or gross lameness. Chronic synovitis and macroscopic and microscopic evidence of pathologic changes to the rotator cuff bony insertions, tendons, myotendinous junctions and muscles were observed. Conclusions This study demonstrates feasibility and proof-of-concept for a joint capsule injury model in the canine shoulder. Future work is needed to define the observed pathologic changes and their role in the progression of rotator cuff disease. Ultimately, better understanding of the biologic mechanisms of early progression of rotator cuff disease may lead to clinical interventions to halt or slow this process and avoid the more advanced and often irreversible conditions of large tendon tears with muscle fatty atrophy. PMID:26808837

  12. A joint econometric analysis of seat belt use and crash-related injury severity.

    PubMed

    Eluru, Naveen; Bhat, Chandra R

    2007-09-01

    This paper formulates a comprehensive econometric structure that recognizes two important issues in crash-related injury severity analysis. First, the impact of a factor on injury severity may be moderated by various observed and unobserved variables specific to an individual or to a crash. Second, seat belt use is likely to be endogenous to injury severity. That is, it is possible that intrinsically unsafe drivers do not wear seat belts and are the ones likely to be involved in high injury severity crashes because of their unsafe driving habits. The preceding issues are considered in the current research effort through the development of a comprehensive model of seat belt use and injury severity that takes the form of a joint correlated random coefficients binary-ordered response system. To our knowledge, this is the first instance of such a model formulation and application not only in the safety analysis literature, but in the econometrics literature in general. The empirical analysis is based on the 2003 General Estimates System (GES) data base. Several types of variables are considered to explain seat belt use and injury severity levels, including driver characteristics, vehicle characteristics, roadway design attributes, environmental factors, and crash characteristics. The results, in addition to confirming the effects of various explanatory variables, also highlight the importance of (a) considering the moderating effects of unobserved individual/crash-related factors on the determinants of injury severity and (b) seat belt use endogeneity. From a policy standpoint, the results suggest that seat belt non-users, when apprehended in the act, should perhaps be subjected to both a fine (to increase the chances that they wear seat belts) as well as mandatory enrollment in a defensive driving course (to attempt to change their aggressive driving behaviors).

  13. In-vitro and in-vivo imaging of MMP activity in cartilage and joint injury.

    PubMed

    Fukui, Tomoaki; Tenborg, Elizabeth; Yik, Jasper H N; Haudenschild, Dominik R

    2015-05-08

    Non-destructive detection of cartilage-degrading activities represents an advance in osteoarthritis (OA) research, with implications in studies of OA pathogenesis, progression, and intervention strategies. Matrix metalloproteinases (MMPs) are principal cartilage degrading enzymes that contribute to OA pathogenesis. MMPSense750 is an in-vivo fluorimetric imaging probe with the potential to continuously and non-invasively trace real-time MMP activities, but its use in OA-related research has not been reported. Our objective is to detect and characterize the early degradation activities shortly after cartilage or joint injury with MMPSense750. We determined the appropriate concentration, assay time, and linear range using various concentrations of recombinant MMPs as standards. We then quantified MMP activity from cartilage explants subjected to either mechanical injury or inflammatory cytokine treatment in-vitro. Finally, we performed in-vivo MMP imaging of a mouse model of post-traumatic OA. Our in-vitro results showed that the optimal assay time was highly dependent on the MMP enzyme. In cartilage explant culture media, mechanical impact or cytokine treatment increased MMP activity. Injured knees of mice showed significantly higher fluorescent signal than uninjured knees. We conclude that MMPSense750 detects human MMP activities and can be used for in-vitro study with cartilage, as well as in-vivo studies of knee injury, and can offering real-time insight into the degradative processes that occurring within the joint before structural changes become evident radiographically.

  14. ISAKOS upper extremity committee consensus statement on the need for diversification of the Rockwood classification for acromioclavicular joint injuries.

    PubMed

    Beitzel, Knut; Mazzocca, Augustus D; Bak, Klaus; Itoi, Eiji; Kibler, William B; Mirzayan, Raffy; Imhoff, Andreas B; Calvo, Emilio; Arce, Guillermo; Shea, Kevin

    2014-02-01

    Optimal treatment for the unstable acromioclavicular (AC) joint remains a highly debated topic in the field of orthopaedic medicine. In particular, no consensus exists regarding treatment of grade III injuries, which are classified according to the Rockwood classification by disruption of both the coracoclavicular and AC ligaments. The ISAKOS Upper Extremity Committee has provided a more specific classification of shoulder pathologies to enhance the knowledge on and clinical approach to these injuries. We suggest the addition of grade IIIA and grade IIIB injuries to a modified Rockwood classification. Grade IIIA injuries would be defined by a stable AC joint without overriding of the clavicle on the cross-body adduction view and without significant scapular dysfunction. The unstable grade IIIB injury would be further defined by therapy-resistant scapular dysfunction and an overriding clavicle on the cross-body adduction view.

  15. Exploiting endogenous fibrocartilage stem cells to regenerate cartilage and repair joint injury

    PubMed Central

    Embree, Mildred C.; Chen, Mo; Pylawka, Serhiy; Kong, Danielle; Iwaoka, George M.; Kalajzic, Ivo; Yao, Hai; Shi, Chancheng; Sun, Dongming; Sheu, Tzong-Jen; Koslovsky, David A.; Koch, Alia; Mao, Jeremy J.

    2016-01-01

    Tissue regeneration using stem cell-based transplantation faces many hurdles. Alternatively, therapeutically exploiting endogenous stem cells to regenerate injured or diseased tissue may circumvent these challenges. Here we show resident fibrocartilage stem cells (FCSCs) can be used to regenerate and repair cartilage. We identify FCSCs residing within the superficial zone niche in the temporomandibular joint (TMJ) condyle. A single FCSC spontaneously generates a cartilage anlage, remodels into bone and organizes a haematopoietic microenvironment. Wnt signals deplete the reservoir of FCSCs and cause cartilage degeneration. We also show that intra-articular treatment with the Wnt inhibitor sclerostin sustains the FCSC pool and regenerates cartilage in a TMJ injury model. We demonstrate the promise of exploiting resident FCSCs as a regenerative therapeutic strategy to substitute cell transplantation that could be beneficial for patients suffering from fibrocartilage injury and disease. These data prompt the examination of utilizing this strategy for other musculoskeletal tissues. PMID:27721375

  16. Diagnosis and prevention of temporomandibular joint (TMJ) or odontostomatognathic (OSG) injury in dental practice.

    PubMed

    Abdel-Fattah, R A

    1990-04-01

    Malpractice lawsuit cases due to temporomandibular joint/soft tissue injuries following dental therapy are increasing. Therefore, dentists and their staffs must know how to recognize, document and avoid any possible aggravation or precipitation of TMJ disorder. TMJ anatomy, biomechanics and mechanisms of TMJ injuries are presented. Etiological factors such as psychological factors, parafunctional activities, malocclusion, trauma, iatrogenic causes, systemic conditions, developmental disorders, neoplastic growth or medications are discussed. Preventive measures addressed include: history-taking, patient examination, complete records, the assessment of the patient's general condition, documentation of pre-existing findings, informing and educating the patient, performing only the necessary procedures, modifying appointments, selecting less traumatic dental techniques, avoiding sudden occlusal alterations and preparedness to handle unwanted complications.

  17. Targeting pro-inflammatory cytokines following joint injury: acute intra-articular inhibition of interleukin-1 following knee injury prevents post-traumatic arthritis

    PubMed Central

    2014-01-01

    Introduction Post-traumatic arthritis (PTA) is a progressive, degenerative response to joint injury, such as articular fracture. The pro-inflammatory cytokines, interleukin 1(IL-1) and tumor necrosis factor alpha (TNF-α), are acutely elevated following joint injury and remain elevated for prolonged periods post-injury. To investigate the role of local and systemic inflammation in the development of post-traumatic arthritis, we targeted both the initial acute local inflammatory response and a prolonged 4 week systemic inflammatory response by inhibiting IL-1 or TNF-α following articular fracture in the mouse knee. Methods Anti-cytokine agents, IL-1 receptor antagonist (IL-1Ra) or soluble TNF receptor II (sTNFRII), were administered either locally via an acute intra-articular injection or systemically for a prolonged 4 week period following articular fracture of the knee in C57BL/6 mice. The severity of arthritis was then assessed at 8 weeks post-injury in joint tissues via histology and micro computed tomography, and systemic and local biomarkers were assessed in serum and synovial fluid. Results Intra-articular inhibition of IL-1 significantly reduced cartilage degeneration, synovial inflammation, and did not alter bone morphology following articular fracture. However, systemic inhibition of IL-1, and local or systemic inhibition of TNF provided no benefit or conversely led to increased arthritic changes in the joint tissues. Conclusion These results show that intra-articular IL-1, rather than TNF-α, plays a critical role in the acute inflammatory phase of joint injury and can be inhibited locally to reduce post-traumatic arthritis following a closed articular fracture. Targeted local inhibition of IL-1 following joint injury may represent a novel treatment option for PTA. PMID:24964765

  18. THE EFFECT OF CONSERVATIVELY TREATED ACL INJURY ON KNEE JOINT POSITION Sense

    PubMed Central

    Herrington, Lee

    2016-01-01

    ABSTRACT Background Proprioception is critical for effective movement patterns. However, methods of proprioceptive measurement in previous research have been inconsistent and lacking in reliability statistics making it applications to clinical practice difficult. Researchers have suggested that damage to the anterior cruciate ligament (ACL) can alter proprioceptive ability due to a loss of functioning mechanoreceptors. The majority of patients opt for reconstructive surgery following this injury. However, some patients chose conservative rehabilitation options rather than surgical intervention. Purpose The purpose of this study was to determine the effect of ACL deficiency on knee joint position sense following conservative, non-operative treatment and return to physical activity. A secondary purpose was to report the reliability and measurement error of the technique used to measure joint position sense, (JPS) and comment on the clinical utility of this measurement. Study Design Observational study design using a cross-section of ACL deficient patients and matched uninjured controls. Methods Twenty active conservatively treated ACL deficient patients who had returned to physical activity and twenty active matched controls were included in the study. Knee joint position sense was measured using a seated passive-active reproductive angle technique. The average absolute angle of error score, between 10 °-30 ° of knee flexion was determined. This error score was derived from the difference between the target and repositioning angle. Results The ACL deficient patients had a greater error score (7.9 °±3.6) and hence poorer static proprioception ability that both the contra-lateral leg (2.0 °±1.6; p = 0.0001) and the control group (2.6 °±0.9; p = 0.0001). The standard error of the mean (SEM) of this JPS technique was 0.5 ° and 0.2 ° and the minimum detectable change (MDC) was 1.3 ° and 0.4 ° on asymptomatic and symptomatic subjects

  19. Changes in Joint Contact Mechanics in a Large Quadrupedal Animal Model After Partial Meniscectomy and a Focal Cartilage Injury.

    PubMed

    Heckelsmiller, David J; James Rudert, M; Baer, Thomas E; Pedersen, Douglas R; Fredericks, Douglas C; Goetz, Jessica E

    2017-05-01

    Acute mechanical damage and the resulting joint contact abnormalities are central to the initiation and progression of post-traumatic osteoarthritis (PTOA). Study of PTOA is typically performed in vivo with replicate animals using artificially induced injury features. The goal of this work was to measure changes in a joint contact stress in the knee of a large quadruped after creation of a clinically realistic overload injury and a focal cartilage defect. Whole-joint overload was achieved by excising a 5-mm wedge of the anterior medial meniscus. Focal cartilage defects were created using a custom pneumatic impact gun specifically developed and mechanically characterized for this work. To evaluate the effect of these injuries on joint contact mechanics, Tekscan (Tekscan, Inc., South Boston, MA) measurements were obtained pre-operatively, postmeniscectomy, and postimpact (1.2-J) in a nonrandomized group of axially loaded cadaveric sheep knees. Postmeniscectomy, peak contact stress in the medial compartment is increased by 71% (p = 0.03) and contact area is decreased by 35% (p = 0.001); the center of pressure (CoP) shifted toward the cruciate ligaments in both the medial (p = 0.004) and lateral (p = 0.03) compartments. The creation of a cartilage defect did not significantly change any aspect of contact mechanics measured in the meniscectomized knee. This work characterizes the mechanical environment present in a quadrupedal animal knee joint after two methods to reproducibly induce joint injury features that lead to PTOA.

  20. Upper extremity interaction with a helicopter side airbag: injury criteria for dynamic hyperextension of the female elbow joint.

    PubMed

    Duma, Stefan M; Hansen, Gail A; Kennedy, Eric A; Rath, Amber L; McNally, Craig; Kemper, Andrew R; Smith, Eric P; Brolinson, P Gunnar; Stitzel, Joel D; Davis, Martin B; Bass, Cameron R; Brozoski, Frederick T; McEntire, B Joseph; Alem, Nabih M; Crowley, John S

    2004-11-01

    This paper describes a three part analysis to characterize the interaction between the female upper extremity and a helicopter cockpit side airbag system and to develop dynamic hyperextension injury criteria for the female elbow joint. Part I involved a series of 10 experiments with an original Army Black Hawk helicopter side airbag. A 5(th) percentile female Hybrid III instrumented upper extremity was used to demonstrate side airbag upper extremity loading. Two out of the 10 tests resulted in high elbow bending moments of 128 Nm and 144 Nm. Part II included dynamic hyperextension tests on 24 female cadaver elbow joints. The energy source was a drop tower utilizing a three-point bending configuration to apply elbow bending moments matching the previously conducted side airbag tests. Post-test necropsy showed that 16 of the 24 elbow joint tests resulted in injuries. Injury severity ranged from minor cartilage damage to more moderate joint dislocations and severe transverse fractures of the distal humerus. Peak elbow bending moments ranged from 42.4 Nm to 146.3 Nm. Peak bending moment proved to be a significant indicator of any elbow injury (p = 0.02) as well as elbow joint dislocation (p = 0.01). Logistic regression analyses were used to develop single and multiple variate injury risk functions. Using peak moment data for the entire test population, a 50% risk of obtaining any elbow injury was found at 56 Nm while a 50% risk of sustaining an elbow joint dislocation was found at 93 Nm for the female population. These results indicate that the peak elbow bending moments achieved in Part I are associated with a greater than 90% risk for elbow injury. Subsequently, the airbag was re-designed in an effort to mitigate this as well as the other upper extremity injury risks. Part III assessed the redesigned side airbag module to ensure injury risks had been reduced prior to implementing the new system. To facilitate this, 12 redesigned side airbag deployments were conducted

  1. Degenerative changes of the sacroiliac auricular joint surface-validation of influential factors.

    PubMed

    Nishi, Keita; Saiki, Kazunobu; Imamura, Takeshi; Okamoto, Keishi; Wakebe, Tetsuaki; Ogami, Keiko; Hasegawa, Takashi; Moriuchi, Takefumi; Sakamoto, Junya; Manabe, Yoshitaka; Tsurumoto, Toshiyuki

    2016-06-24

    The purpose of this study was to clarify the relevance of degenerative changes in the sacroiliac joint (SIJ) and the joints in the lower limb and lumbar spine using age estimation methods. We also examined the shape of the auricular surface to determine the effect of degenerative changes on each joint. A total of 200 iliac auricular surfaces from 100 Japanese male skeletons were examined macroscopically in accordance with conventional methods of age estimation. From the obtained estimated age, we calculated the deflection values, which represented the degree of degenerative changes of the joints. For comparison, we used osteophyte score data of the hip, knee, and zygapophyseal joints in lumbar spines from previous studies which had used the same bone specimens. As a quantitative indicator of auricular surface morphology, we defined the constriction ratio (CR) of the auricular surface and compared the CR values obtained with various measured values. Degenerative changes in the SIJ were positively correlated with those in both the hip joint and zygapophyseal joint, but a correlation with knee joints was found only on the left side. In skeletons from individuals aged ≥60 years as time of death, the CR was significantly different between the group with high scores and those with low scores in both the hip and sacroiliac joints. It has been suggested that degenerative changes in SIJs interact with those in the hip joint and zygapophyseal joint. In addition, the shape of the auricular surface may also be a relevant factor for degenerative changes in these joints.

  2. Anatomical study of the ligamentous attachments and articular surfaces of the trapeziometacarpal joint. Consequences on surgical management of its osteoarthrosis.

    PubMed

    Maes-Clavier, C; Bellemère, P; Gabrion, A; David, E; Rotari, V; Havet, E

    2014-04-01

    In the goal to optimize conservative surgical techniques of the trapeziometacarpal joint in cases of moderate osteoarthritis, we have defined the relationships between the ligamentous attachments and the articular surfaces onto the trapezium and the first metacarpal bone on the one hand, and the dorsovolar and the transverse diameters of the articular surfaces on the other hand. Thirty-six trapeziometacarpal joints (from 18 fresh cadavers) were studied. They were separated into two groups depending on the macroscopic assessment of chondral disease. Group A included stages I to III (no osteoarthritis or moderate osteoarthritis), group B included stages IV (major cartilage destruction). The dorsovolar and transverse sizes of the articular surfaces were measured. Dorsoradial ligament (DRL), posterior oblique ligament (POL), intermetacarpal ligament (IML), ulnar collateral ligament (UCL) and anterior oblique ligament (AOL) were dissected and the distance between their attachments and the articular surfaces were measured. Group A included 17 joints (71% males) and group B included 19 joints (95% females). For the first metacarpal bone, the average ratio between the dorsovolar diameter and the transverse diameter of metacarpal articular surfaces was significantly higher in group B and the average distance between the ligamentous attachments and the articular surface was more than two millimeters, except for the DRL in group B. For the trapezium, only the posterior ligaments (DRL and POL) of group A were inserted at a mean distance more than two millimeters from the articular surfaces. Dorsovolar length of the metacarpal articular surface was higher for osteoarthritis cases. This difference can be explained by the existence of a palmar osteophyte that was always found in stage IV. Describing a map of the ligamentous attachment distance from the articular surface could help surgeons to avoid the ligamentous injury during minimal osteochondral resection.

  3. [Injuries to the superior ankle joint from the viewpoint of accident surgery].

    PubMed

    Zwipp, H

    1991-12-01

    The treatment of bony, osteochondral, and ligamentous injuries of the tibio-talar joint requires precise preoperative planning by radiological investigation. This is essential to a correct understanding of the underlying pathology and will allow a proper classification of the injury, which is the basis of treatment. Conventional radiography using anteroposterior and lateral X-rays with comparative views of the noninjured side and, if necessary, rotated spot views and tomography are of high value especially in osteochondral fractures of the talus. Intraoperative control images in both planes after osteosynthesis are mandatory. For evaluation of the postoperative course and severity of arthrosis formation, the classification system of Bargon has proved its worth. In addition, tomography of the tibio-talar joint in two planes is useful especially in tibial pilon fractures, some malleolar fractures, and peripheral talar fractures. In talar fracture dislocations with concomitant compartment syndrome an emergency CT scan can be helpful to determine the optimal surgical approach. In these cases a 3-D reconstruction also might be of assistance. If there is evidence of partial or total talar necrosis, magnetic resonance imaging can be extremely helpful. However, in most cases implants considerably limit the validity of the image obtained. Ultrasonography offers a noninvasive, reproducible, and very inexpensive alternative and should be performed in cases of chondral-osteochondral talar rim avulsions and juvenile osteochondral ligament ruptures. It can also be used as a dynamic method for stress examination in fibular ligament ruptures and soft tissue injuries such as dislocation of the peroneal tendons. The use of Arthrography, stress tenography, and Arthro-CT scan nowadays has become extremely limited.

  4. In-vitro and in-vivo imaging of MMP activity in cartilage and joint injury

    SciTech Connect

    Fukui, Tomoaki; Tenborg, Elizabeth; Yik, Jasper H.N.; Haudenschild, Dominik R.

    2015-05-08

    Non-destructive detection of cartilage-degrading activities represents an advance in osteoarthritis (OA) research, with implications in studies of OA pathogenesis, progression, and intervention strategies. Matrix metalloproteinases (MMPs) are principal cartilage degrading enzymes that contribute to OA pathogenesis. MMPSense750 is an in-vivo fluorimetric imaging probe with the potential to continuously and non-invasively trace real-time MMP activities, but its use in OA-related research has not been reported. Our objective is to detect and characterize the early degradation activities shortly after cartilage or joint injury with MMPSense750. We determined the appropriate concentration, assay time, and linear range using various concentrations of recombinant MMPs as standards. We then quantified MMP activity from cartilage explants subjected to either mechanical injury or inflammatory cytokine treatment in-vitro. Finally, we performed in-vivo MMP imaging of a mouse model of post-traumatic OA. Our in-vitro results showed that the optimal assay time was highly dependent on the MMP enzyme. In cartilage explant culture media, mechanical impact or cytokine treatment increased MMP activity. Injured knees of mice showed significantly higher fluorescent signal than uninjured knees. We conclude that MMPSense750 detects human MMP activities and can be used for in-vitro study with cartilage, as well as in-vivo studies of knee injury, and can offering real-time insight into the degradative processes that occurring within the joint before structural changes become evident radiographically. - Highlights: • MMPSense750 is near-infrared fluorescent probe which can detect MMP activity. • MMPSense750 can detect human MMP-3, -9, and -13. • The reaction kinetics with MMPSense750 were different for the three MMPs. • MMPSense750 can visualized real time MMP activity in mouse injured knees. • MMPSense750 is convenient tool to evaluate real-time MMP activity non-invasively.

  5. Biepicondylar fracture dislocation of the elbow joint concomitant with ulnar nerve injury

    PubMed Central

    Konya, M Nuri; Aslan, Ahmet; Sofu, Hakan; Yıldırım, Timur

    2013-01-01

    In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up. PMID:23610759

  6. Biepicondylar fracture dislocation of the elbow joint concomitant with ulnar nerve injury.

    PubMed

    Konya, M Nuri; Aslan, Ahmet; Sofu, Hakan; Yıldırım, Timur

    2013-04-18

    In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up.

  7. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2

  8. Topical diagnostics of traumatic condylar injuries and alloplastic reconstruction of temporomandibular joint heads.

    PubMed

    Gvenetadze, Z; Danelia, T; Nemsadze, G; Gvenetadze, G

    2014-04-01

    Condylar fractures have an important place in facial traumatic injuries. Classification of condylar fractures according to clinical-anatomic picture is common in clinical practice. According to this classification there are: 1) fractures of mandibular joint head, aka intraarticular fractures, 2) condylar neck fractures or high extra articular fractures, 3) condylar base fractures. Radiographic imaging plays important role in diagnosing condylar fractures along with knowledge of clinical symptoms. We used computer tomography imaging in our clinical practice. Three-dimensional imaging of computer tomography gives exact information about location of condylar fractures, impact of fractured fragments, displacement of condylar head from articular fossa. This method is mostly important for the cases which are hard to diagnose (fractures of mandibular joint head, aka intraarticular fractures). For this group of patients surgical treatment is necessary with the method of arthroplasty. We have observed 5 patients with bilateral, fragmented, high condylar fractures. In all cases the surgery was performed on both sides with bone cement and titanium mini-plates. Long-term effects of the treatment included observation from 6 months to 2 years. In all cases anatomic and functional results were good. Shape of the mandible is restored, opening of mouth 3-3.5 cm, absence of malocclusion.

  9. Comparison of Extension Orthosis Versus Percutaneous Pinning of the Distal Interphalangeal Joint for Closed Mallet Injuries.

    PubMed

    Renfree, Kevin J; Odgers, Ryan A; Ivy, Cynthia C

    2016-05-01

    We compared a static extension orthosis with percutaneous pinning of the distal interphalangeal joint (DIPJ) for treatment of closed mallet injuries. After receiving counsel about treatment options, 44 patients (25 women and 19 men; mean age, 57 years) freely chose orthosis and 18 patients (5 women and 13 men; mean age, 51 years) chose pinning. Both the extension orthosis and the pin remained in place for 6 weeks; the pin then was removed, and the care in both groups was transitioned to nighttime orthosis use for an additional 6 weeks. The patients in the pin group were allowed to immediately resume unrestricted activity postoperatively. The mean follow-up was 32 months in the orthosis group and 19 months in the pin group. Final residual extensor lag was better in the pin group (5 vs 10 degrees, P = 0.048). Improvement between the groups was in favor of percutaneous pinning (36 vs 17 degrees, P = 0.001). No correlation was seen between time to treatment (≤14 vs >14 days from injury) and final extensor lag in either group (P = 0.85). The final mean DIPJ flexion was 53 degrees for orthosis and 46 degrees for pinning. Among the patients, 93% of the orthosis group and 100% of the pin group said that they would choose the same treatment again. Both groups had a mean of 5 hand therapy visits during treatment. Two complications occurred in the orthosis group (5%) and 3 (17%) occurred in the pin group. Extension orthotics and pinning are both well-tolerated, effective treatments of mallet injury. The techniques produce satisfactory correction of extensor lag and have high patient satisfaction. Pinning allows better correction of DIPJ extensor lag and results in a smaller degree of final extensor lag. Pinning is more expensive and may result in more DIPJ stiffness (ie, loss of active flexion), but it may be justified in certain patients (eg, medical professionals, food service workers) who would have difficulty working with an orthosis.

  10. [Joint surface resection with a minimally invasive dorsal approach for arthrodesis of the distal interphalangeal joint].

    PubMed

    Ayala-Gamboa, U; Domínguez-Chacón, N D

    2015-01-01

    Degenerative joint disease of the distal interphalangeal joint of the fingers precedes its occurrence in all the remaining regions of the body and produces major disability. We describe a distal interphalangeal arthrodesis technique performed with minimally invasive surgery. Case etiology was varied and mean follow-up was 10 months. All cases healed and functional recovery started at postoperative week two. This is a reproducible technique that produces satisfactory results in the short and medium term.

  11. A novel modelling and simulation method of hip joint surface contact stress.

    PubMed

    Wang, Monan; Wang, Lei; Li, Pengcheng; Fu, Yili

    2017-01-02

    Understanding the hip joint surface contact stress distribution characteristics is helpful to determine hip joint biomechanical features and abnormal pathological behavior. Firstly, a 3-dimensional static hip joint biomechanical model is built using analytical method of model in order to study biomechanical properties including bearing area, stress distribution and the peak value of the contact stress of the femoral head, which reveals the relationship between the biomechanical properties and its geometric parameters. Secondly, based on the finite element analysis of the hip joint model, the contact stress distribution on the surface of femoral head is acquired under the condition of the different joint force and the acetabulum coverage rate. Finally, according to the evaluation of the femoral head surface stress and contact stress peak under different load distribution, accuracy and universality of the biomechanical model is verified.

  12. A surface roughness comparison of cartilage in different types of synovial joints.

    PubMed

    Smyth, Patrick A; Rifkin, Rebecca E; Jackson, Robert L; Hanson, R Reid

    2012-02-01

    The naturally occurring structure of articular cartilage has proven to be an effective means for the facilitation of motion and load support in equine and other animal joints. For this reason, cartilage has been extensively studied for many years. Although the roughness of cartilage has been determined from atomic force microscopy (AFM) and other methods in multiple studies, a comparison of roughness to joint function has not be completed. It is hypothesized that various joint types with different motions and regimes of lubrication have altered demands on the articular surface that may affect cartilage surface properties. Micro- and nanoscale stylus profilometry was performed on the carpal cartilage harvested from 16 equine forelimbs. Eighty cartilage surface samples taken from three different functioning joint types (radiocarpal, midcarpal, and carpometacarpal) were measured by a Veeco Dektak 150 Stylus Surface Profilometer. The average surface roughness measurements were statistically different for each joint. This indicates that the structure of cartilage is adapted to, or worn by, its operating environment. Knowledge of cartilage micro- and nanoscale roughness will assist the future development and design of treatments for intra- articular substances or surfaces to preserve joint integrity and reduce limitations or loss of joint performance.

  13. Joint-specific changes in locomotor complexity in the absence of muscle atrophy following incomplete spinal cord injury

    PubMed Central

    2013-01-01

    Background Following incomplete spinal cord injury (iSCI), descending drive is impaired, possibly leading to a decrease in the complexity of gait. To test the hypothesis that iSCI impairs gait coordination and decreases locomotor complexity, we collected 3D joint angle kinematics and muscle parameters of rats with a sham or an incomplete spinal cord injury. Methods 12 adult, female, Long-Evans rats, 6 sham and 6 mild-moderate T8 iSCI, were tested 4 weeks following injury. The Basso Beattie Bresnahan locomotor score was used to verify injury severity. Animals had reflective markers placed on the bony prominences of their limb joints and were filmed in 3D while walking on a treadmill. Joint angles and segment motion were analyzed quantitatively, and complexity of joint angle trajectory and overall gait were calculated using permutation entropy and principal component analysis, respectively. Following treadmill testing, the animals were euthanized and hindlimb muscles removed. Excised muscles were tested for mass, density, fiber length, pennation angle, and relaxed sarcomere length. Results Muscle parameters were similar between groups with no evidence of muscle atrophy. The animals showed overextension of the ankle, which was compensated for by a decreased range of motion at the knee. Left-right coordination was altered, leading to left and right knee movements that are entirely out of phase, with one joint moving while the other is stationary. Movement patterns remained symmetric. Permutation entropy measures indicated changes in complexity on a joint specific basis, with the largest changes at the ankle. No significant difference was seen using principal component analysis. Rats were able to achieve stable weight bearing locomotion at reasonable speeds on the treadmill despite these deficiencies. Conclusions Decrease in supraspinal control following iSCI causes a loss of complexity of ankle kinematics. This loss can be entirely due to loss of supraspinal control in

  14. The Effects of Generalized Joint Laxity on Risk of Anterior Cruciate Ligament Injury in Young Female Athletes

    PubMed Central

    Myer, Gregory D.; Ford, Kevin R.; Paterno, Mark V.; Nick, Todd G.; Hewett, Timothy E.

    2012-01-01

    Background Women who participate in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than men. Purpose To prospectively determine if female athletes with decreased passive knee joint restraint (greater joint laxity) and greater side-to-side differences in knee laxity would be at increased risk of anterior cruciate ligament injury. Study Design Case control study; Level of evidence, 3. Methods From 1558 female soccer and basketball players who were prospectively screened, 19 went on to tear their anterior cruciate ligaments. Four height- and mass-matched control subjects were selected from the uninjured screened athletes for comparison with each of the 19 injured subjects, making a total of 95 subjects (19 injured; 76 uninjured). Generalized joint-laxity tests and anterior-posterior tibiofemoral translation were quantified using the CompuKT knee arthrometer. A multivariable logistic regression model was constructed to determine predictors of anterior cruciate ligament injury status from recorded laxity measures. Results A multivariable logistic regression model (chi-square = 18.6; P = .002) used the independent variables laxity measures of knee hyperextension (P = .02), wrist and thumb to forearm opposition (P = .80), fifth-finger hyperextension >90° (P = .71), side-to-side differences in anterior-posterior tibiofemoral translation (P = .002), and prior knee injury (P = .22) to predict anterior cruciate ligament–injury status. The validated C statistic, or validated area under the receiver operating characteristic curve, was 0.72. For every 1.3-mm increase in side-to-side differences in anterior-posterior knee displacement, the odds of anterior cruciate ligament–injured status increased 4-fold (95% confidence interval, 1.68–9.69). A positive measure of knee hyperextension increased the odds of anterior cruciate ligament–injured status 5-fold (95% confidence interval, 1.24–18.44). Conclusion The current results

  15. The joint effect of surface microtopography and near-surface structure on microcontact conditions

    SciTech Connect

    McCool, J.I.

    1990-11-01

    This is the Final Technical Report of the project The Joint Effect of Surface Microtopography and Near Surface Structure on Microcontact Conditions The purpose of this project was to extend, apply, and evaluate the usefuleness of, microcontact models for assessing the tribological performance of machine elements in rolling/sliding contact. Because of their projected importance to the field of energy conservation, emphasis was placed on application to ceramic and coated specimens. The project was multi-institutional as well as multi-disciplinary with technical contributions in testing and the evaluation of specimens by the Argonne National Laboratory (G. Fenske), Oak Ridge National Laboratory (P. Blau), and the University of Michigan (K. Ludema and Layo Ajayi). To accomplish the Project aims it was necessary to extend the state-of-the-art of microcontact modelling. 59 refs., 46 figs., 35 tabs.

  16. Association of lower limb injury with boot cleat design and playing surface in elite soccer.

    PubMed

    O'Connor, Anne-Marie; James, Iain T

    2013-06-01

    Reducing external injury risk factors associated with the boot-surface interaction is important in reducing the incidence and severity of foot and ankle injury. A review of prospective football (soccer) injury epidemiology studies determined that the incidence of noncontact ankle sprain injury is relatively high. Research on the impact of cleat shape and configuration and boot design on the boot-surface interaction is providing new understanding of the impact on player biomechanics and injury risk but is not keeping pace with commercial advances in boot design and innovation in natural and synthetic turf surface technology.

  17. Activity vs. rest in the treatment of bone, soft tissue and joint injuries.

    PubMed Central

    Buckwalter, J. A.

    1995-01-01

    One of the most important advances in the treatment of musculoskeletal injuries has come from understanding that controlled early resumption of activity can promote restoration of function, and that treatment of injuries with prolonged rest may delay recovery and adversely affect normal tissues. In the last decade of the nineteenth century two widely respected orthopaedists with extensive clinical experience strongly advocated opposing treatments of musculoskeletal injuries. Hugh Owen Thomas in Liverpool believed that enforced, uninterrupted prolonged rest produced the best results. He noted that movement of injured tissues increased inflammation, and that, "It would indeed be as reasonable to attempt to cure a fever patient by kicking him out of bed, as to benefit joint disease by a wriggling at the articulation." Just Lucas-Championnier in Paris took the opposite position. He argued that early controlled active motion accelerated restoration of function, although he noted that mobility had to be given in limited doses. In general, Thomas' views met with greater acceptance in the early part of this century, but experimental studies of the last several decades generally support Lucas-Championneir. They confirm and help explain the deleterious effects of prolonged rest and the beneficial effects of activity on the musculoskeletal tissues. They have shown that maintenance of normal bone, tendon and ligament, articular cartilage and muscle structure and composition require repetitive use, and that changes in the patterns of tissue loading can strengthen or weaken normal tissues. Although all the musculoskeletal tissues can respond to repetitive loading, they vary in the magnitude and type of response to specific patterns of activity. Furthermore, their responsiveness may decline with increasing age. Skeletal muscle and bone demonstrate the most apparent response to changes in activity in individuals of any age. Cartilage and dense fibrous tissues also can respond to

  18. Quantitation of articular surface topography and cartilage thickness in knee joints using stereophotogrammetry.

    PubMed

    Ateshian, G A; Soslowsky, L J; Mow, V C

    1991-01-01

    An analytical stereophotogrammetry (SPG) technique has been developed based upon some of the pioneering work of Selvik [Ph.D. thesis, University of Lund, Sweden (1974)] and Huiskes and coworkers [J. Biomechanics 18, 559-570 (1985)], and represents a fundamental step in the construction of biomechanical models of diarthrodial joints. Using this technique, the precise three-dimensional topography of the cartilage surfaces of various diarthrodial joints has been obtained. The system presented in this paper delivers an accuracy of 90 microns in the least favorable conditions with 95% coverage using the same calibration method as Huiskes et al. (1985). In addition, a method has been developed, using SPG, to quantitatively map the cartilage thickness over the entire articular surface of a joint with a precision of 134 microns (95% coverage). In the present study, our SPG system has been used to quantify the topography, including surface area, of the articular surfaces of the patella, distal femur, tibial plateau, and menisci of the human knee. Furthermore, examples of cartilage thickness maps and corresponding thickness data including coefficient of variation, minimum, maximum, and mean cartilage thickness are also provided for the cartilage surfaces of the knee. These maps illustrate significant variations over the joint surfaces which are important in the determination of the stresses and strains within the cartilage during diarthrodial joint function. In addition, these cartilage surface topographies and thickness data are essential for the development of anatomically accurate finite element models of diarthrodial joints.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Arthroscopic-assisted repair of triangular fibrocartilage complex foveal avulsion in distal radioulnar joint injury

    PubMed Central

    Woo, Sung Jong; Jegal, Midum; Park, Min Jong

    2016-01-01

    Background: Disruption of the triangular fibrocartilage complex (TFCC) foveal insertion can lead to distal radioulnar joint (DRUJ) instability accompanied by ulnar-sided pain, weakness, snapping, and limited forearm rotation. We investigated the clinical outcomes of patients with TFCC foveal tears treated with arthroscopic-assisted repair. Materials and Methods: Twelve patients underwent foveal repair of avulsed TFCC with the assistance of arthroscopy between 2011 and 2013. These patients were followed up for an average of 19 months (range 14–25 months). The avulsed TFCC were reattached to the fovea using a transosseous pull-out suture or a knotless suture anchor. At the final followup, the range of motion, grip strength and DRUJ stability were measured as objective outcomes. Subjective outcomes were assessed using the Visual Analog Scale (VAS) for pain, patient rated wrist evaluation (PRWE), Disabilities of the Arm, Shoulder and Hand questionnaire (DASH score) and return to work. Results: Based on the DRUJ stress test, 5 patients had normal stability and 7 patients showed mild laxity as compared with the contralateral side. Postoperatively, the mean range of pronation supination increased from 141° to 166°, and the mean VAS score for pain decreased from 5.3 to 1.7 significantly. The PRWE and DASH questionnaires also showed significant functional improvement. All patients were able to return to their jobs. However, two patients complained of persistent pain. Conclusions: Arthroscopically assisted repair of TFCC foveal injury can provide significant pain relief, functional improvement and restoration of DRUJ stability. PMID:27293286

  20. Manual Medicine Related Injuries Experienced by Physicians: A Missing Aspect in Therapies Using Manipulation of Joints

    PubMed Central

    Steinhaeuser, Jost; Oser, Andreas

    2015-01-01

    Background. In 2010 Manual Medicine (MM) was the second most common additional qualification among physicians in Germany, which is recommended to be used in several guidelines. Aim of this analysis was to raise the amount of information on MM related injuries (MMri) experienced by physicians at any point of their career while applying MM. Methods. Data on MMri of a questionnaire that was used to gain first insights into MM in Germany from a health services research perspective was analysed. Results. A total of 301 physicians (20% female) participated in this study. The participants' mean age was 46. 11% of the participants experienced some kind of MMri during their career as a MM provider. In the three worst cases these MMri were fractures and therefore classified as moderate. Mild MMri were joint dysfunction syndromes (N = 30), distortions of fingers (N = 7), and shoulder pain (N = 3). Subgroup analyses showed no significant differences in the rate of MMri when comparing gender, provider organizations for postgraduate MM courses, and medical disciplines. Conclusion. Our analysis shows risks for providers of MM. As this analysis suffers from the risk of recall bias, future studies should be performed to get more insights into this aspect of MM. PMID:25815036

  1. Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair

    DTIC Science & Technology

    2015-09-01

    combat injuries experienced during deployments, training and generally active life-style can cause traumatic mechanical destruction or progressive...accelerate the rate of recovery and therefore shorten the time away from active duty status and the duration of rehabilitation, while allowing full... activities or phases of the project, identify these dates and show actual completion dates or the percentage of completion

  2. Surface Modifications for Improved Wear Performance in Artificial Joints: A Review

    NASA Astrophysics Data System (ADS)

    Sullivan, Stacey J. L.; Topoleski, L. D. Timmie

    2015-11-01

    Artificial joint replacement is one of the most successful treatments for arthritis. Excellent wear and corrosion resistance, together with high strength and fracture toughness, are fundamental requirements for implant materials. Wear and/or corrosion of the materials used in artificial joints may lead to implant failure. Therefore, hard and wear-resistant materials, like cobalt-chromium-molybdenum and ceramic, are currently used as bearing surfaces. However, even using such hard materials, wear and/or corrosion related failure of artificial joints remains a central concern. One primary goal in orthopedic biomaterials research is to create more wear-resistant surfaces. Different technologies have been used to create new surfaces, or to modify existing surfaces, to prevent wear. It is the intent of this overview first to provide a summary of materials currently used as bearing surfaces in artificial joints, their functions, and their contributions to device longevity. Then, we will discuss advancements in modifying those bearing surfaces to produce more wear-resistant artificial joints.

  3. Upper limb joint kinetics of three sitting pivot wheelchair transfer techniques in individuals with spinal cord injury

    PubMed Central

    Kankipati, Padmaja; Boninger, Michael L.; Gagnon, Dany; Cooper, Rory A.; Koontz, Alicia M.

    2015-01-01

    Study design Repeated measures design. Objective This study compared the upper extremity (UE) joint kinetics between three transfer techniques. Setting Research laboratory. Methods Twenty individuals with spinal cord injury performed three transfer techniques from their wheelchair to a level tub bench. Two of the techniques involved a head–hips method with leading hand position close (HH-I) and far (HH-A) from the body, and the third technique with the trunk upright (TU) and hand far from body. Motion analysis equipment recorded upper body movements and force sensors recorded their hand and feet reaction forces during the transfers. Results Several significant differences were found between HH-A and HH-I and TU and HH-I transfers indicating that hand placement was a key factor influencing the UE joint kinetics. Peak resultant hand, elbow, and shoulder joint forces were significantly higher for the HH-A and TU techniques at the trailing arm (P < 0.036) and lower at the leading arm (P < 0.021), compared to the HH-I technique. Conclusion Always trailing with the same arm if using HH-A or TU could predispose that arm to overuse related pain and injuries. Technique training should focus on initial hand placement close to the body followed by the amount of trunk flexion needed to facilitate movement. PMID:25130053

  4. Gender-related differences in lower limb alignment, range of joint motion, and the incidence of sports injuries in Japanese university athletes

    PubMed Central

    Mitani, Yasuhiro

    2017-01-01

    [Purpose] To investigate the gender-related differences in lower limb alignment, range of joint motion, and history of lower limb sports injuries in Japanese university athletes. [Subjects and Methods] The subjects were 224 Japanese university athletes (154 males and 70 females). The quadriceps angle (Q-angle), arch height index, and ranges of internal and external rotation of the hip joints were measured. History of lower limb sports injury was surveyed using a questionnaire. [Results] Females had a significantly higher Q-angle and hip joint internal rotation angle and a significantly lower arch height index than males. The survey revealed that a significantly higher proportion of females had a history of lower limb sports injuries, and that the proportion of those with a history of foot/ankle injuries was particularly high. [Conclusion] These results suggested that females experience more lower limb sports injuries than males, and that a large proportion of these injuries involve the foot/ankle. Reduced lower limb alignment and increased range of joint motion in females may be risk factors for injury because they lead to increased physical stress being exerted on the lower legs during sporting activities. PMID:28210029

  5. Assessing ozone injury to leaves of phaseolus vulgaris (pinto) by surface temperature imaging

    SciTech Connect

    Guralnick, L.J. ); Heath, R.L.; Miller, R. )

    1989-04-01

    Ozone injury to leaves can be assessed several ways, but most involve waiting for the injury to become visible or using destructive chemical methods. Also most methods can not discriminate regions of differential injury. An infra-red thermal imaging system can be used to monitor surface temperature changes, partially mirroring changes in transpiration rate induced by ozone injury. Plants were exposed to various levels of ozone and analyzed by the infra-red image patterns pre- and post-fumigation. Leaves (2 and 24 hr post-fumigation) showed an increased surface temperature even under conditions where visible injury was not apparent. The increase in surface temperature correlated with reductions in transpiration. Under carefully controlled irradiation conditions the infra-red image can be used as a non-destructive method to assess ozone injury.

  6. Joint loads resulting in ACL rupture: Effects of age, sex, and body mass on injury load and mode of failure in a mouse model.

    PubMed

    Blaker, Carina L; Little, Christopher B; Clarke, Elizabeth C

    2016-09-07

    Anterior cruciate ligament (ACL) tears are a common knee injury with a known but poorly understood association with secondary joint injuries and post-traumatic osteoarthritis (OA). Female sex and age are known risk factors for ACL injury but these variables are rarely explored in mouse models of injury. This study aimed to further characterize a non-surgical ACL injury model to determine its clinical relevance across a wider range of mouse specifications. Cadaveric and anesthetized C57BL/6 mice (9-52 weeks of age) underwent joint loading to investigate the effects of age, sex, and body mass on ACL injury mechanisms. The ACL injury load (whole joint load required to rupture the ACL) was measured from force-displacement data, and mode of failure was assessed using micro-dissection and histology. ACL injury load was found to increase with body mass and age (p < 0.001) but age was not significant when controlling for mass. Sex had no effect. In contrast, the mode of ACL failure varied with both age and sex groups. Avulsion fractures (complete or mixed with mid-substance tears) were common in all age groups but the proportion of mixed and mid-substance failures increased with age. Females were more likely than males to have a major avulsion relative to a mid-substance tear (p < 0.01). This data compliments studies in human cadaveric knees, and provides a basis for determining the severity of joint injury relative to a major ACL tear in mice, and for selecting joint loading conditions in future experiments using this model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  7. Incorporation of lower neck shear forces to predict facet joint injury risk in low-speed automotive rear impacts.

    PubMed

    Stemper, Brian D; Storvik, Steven G

    2010-06-01

    Lower neck shear force remains a viable candidate for a low-velocity automotive rear-impact injury criterion. Data were previously reported to demonstrate high correlations between the magnitude of lower neck shear force and lower cervical spine facet joint motions. The present study determined the ability of lower neck shear force to predict soft-tissue injury risk in simulated automotive rear impacts. Rear-impact tests were conducted at two velocities and with two seatback orientations using a Hybrid III anthropomorphic test device (ATD) and stock automobile seats from 2007 model year vehicles. Higher velocities and more vertical seatback orientations were associated with higher injury risk based on computational modeling simulations performed in this study. Six cervical spine injury criteria including NIC, Nij, Nkm, LNL, and lower neck shear force and bending moment, increased with impact velocity. NIC, Nij, and shear force were most sensitive to changes in impact velocity. Four metrics, including Nkm, LNL, and lower neck shear force and bending moment, increased for tests with more vertical seatback orientations. Shear force was most sensitive to changes in seatback orientation. Peak values for shear force, NIC, and Nij occurred approximately at the time of head restraint contact for all four test conditions. Therefore, of the six investigated metrics, lower neck shear force was the only metric to demonstrate consistency with regard to injury risk and timing of peak magnitudes. These results demonstrate the ability of lower neck shear force to predict injury risk during low velocity automotive rear impacts and warrant continued investigation into the sensitivity and applicability of this metric for other rear-impact conditions.

  8. The Surgical Strategy to Correct the Rotational Imbalance of the Glenohumeral Joint after Brachial Plexus Birth Injury

    PubMed Central

    Bahm, J.

    2016-01-01

    In upper brachial plexus birth injury, rotational balance of the glenohumeral joint is frequently affected and contracture in medial rotation of the arm develops, due to a severe palsy or insufficient recovery of the lateral rotators. Some of these children present with a severe glenohumeral joint contracture in the first months, although regular physiotherapy has been provided, a condition associated with a posteriorly subdislocated or dislocated humeral head. These conditions should be screened early by a pediatrician or specialized physiotherapist. Both aspects of muscular weakness affecting the lateral rotators and the initial or progressive glenohumeral deformity and/or subdislocation must be identified and treated accordingly, focusing on the reestablishment of joint congruence and strengthening of the lateral rotators to improve rotational balance, thus working against joint dysplasia and loss of motor function of the shoulder in a growing child. Our treatment strategy adapted over the last 20 years to results from retrospective studies, including biomechanical aspects on muscular imbalance and tendon transfers. With this review, we confront our actual concept to recent literature. PMID:28077955

  9. The Surgical Strategy to Correct the Rotational Imbalance of the Glenohumeral Joint after Brachial Plexus Birth Injury.

    PubMed

    Bahm, J

    2016-01-01

    In upper brachial plexus birth injury, rotational balance of the glenohumeral joint is frequently affected and contracture in medial rotation of the arm develops, due to a severe palsy or insufficient recovery of the lateral rotators. Some of these children present with a severe glenohumeral joint contracture in the first months, although regular physiotherapy has been provided, a condition associated with a posteriorly subdislocated or dislocated humeral head. These conditions should be screened early by a pediatrician or specialized physiotherapist. Both aspects of muscular weakness affecting the lateral rotators and the initial or progressive glenohumeral deformity and/or subdislocation must be identified and treated accordingly, focusing on the reestablishment of joint congruence and strengthening of the lateral rotators to improve rotational balance, thus working against joint dysplasia and loss of motor function of the shoulder in a growing child. Our treatment strategy adapted over the last 20 years to results from retrospective studies, including biomechanical aspects on muscular imbalance and tendon transfers. With this review, we confront our actual concept to recent literature.

  10. Understanding the Acute Skin Injury Mechanism Caused by Player-Surface Contact During Soccer

    PubMed Central

    van den Eijnde, Wilbert A.J.; Peppelman, Malou; Lamers, Edwin A.D.; van de Kerkhof, Peter C.M.; van Erp, Piet E.J.

    2014-01-01

    Background: Superficial skin injuries are considered minor, and their incidence is probably underestimated. Insight into the incidence and mechanism of acute skin injury can be helpful in developing suitable preventive measures and safer playing surfaces for soccer and other field sports. Purpose: To gain insight into the incidence and severity of skin injuries related to soccer and to describe the skin injury mechanism due to player-surface contact. Study Design: Systematic review; Level of evidence, 4. Methods: The prevention model by van Mechelen et al (1992) combined with the injury causation model of Bahr and Krosshaug (2005) were used as a framework for the survey to describe the skin injury incidence and mechanism caused by player-surface contact. Results: The reviewed literature showed that common injury reporting methods are mainly based on time lost from participation or the need for medical attention. Because skin abrasions seldom lead to absence or medical attention, they are often not reported. When reported, the incidence of abrasion/laceration injuries varies from 0.8 to 6.1 injuries per 1000 player-hours. Wound assessment techniques such as the Skin Damage Area and Severity Index can be a valuable tool to obtain a more accurate estimation of the incidence and severity of acute skin injuries. Conclusion: The use of protective equipment, a skin lubricant, or wet surface conditions has a positive effect on preventing abrasion-type injuries from artificial turf surfaces. The literature also shows that essential biomechanical information of the sliding event is lacking, such as how energy is transferred to the area of contact. From a clinical and histological perspective, there are strong indications that a sliding-induced skin lesion is caused by mechanical rather than thermal injury to the skin. PMID:26535330

  11. Surface modification of UHMWPE for use in total joint replacements.

    PubMed

    Zhang, Min; James, Susan P; King, Richard; Beauregard, Guy

    2004-01-01

    To create a hydrophilic, lubricious, more wear-resistant UHMWPE bearing, a novel hyaluronan (HA) derivative and novel UHMWPE-hyaluronan composite were developed. HA was silylated to increase its hydrophobicity and compatibility with UHMWPE. The sily1 HA rapidly diffused into the connected pores of UHMWPE preforms in xylenes solution, and fixed within UHMWPE and on its surface after crosslinking. A micro-composite was obtained after hot-pressing the porous preform. The presence of HA film on the composite surface has been demonstrated through X-Ray photoelectron spectroscopy (XPS) analysis and Toluidine Blue O (TBO) dye assay. The aqueous contact angles of micro-composite samples were significantly lower compared with UHMWPE control samples, and the samples processed with hydrolysis prior to final molding were superior to those processed with hydrolysis after molding.

  12. Joint variability of global runoff and global sea surface temperatures

    USGS Publications Warehouse

    McCabe, G.J.; Wolock, D.M.

    2008-01-01

    Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the analysis period. The annual runoff time series data are combined with gridded annual sea surface temperature data, and the combined dataset is subjected to a principal components analysis (PCA) to identify the primary modes of variability. The first three components from the PCA explain 29% of the total variability in the combined runoff/SST dataset. The first component explains 15% of the total variance and primarily represents long-term trends in the data. The long-term trends in SSTs are evident as warming in all of the oceans. The associated long-term trends in runoff suggest increasing flows for parts of North America, South America, Eurasia, and Australia; decreasing runoff is most notable in western Africa. The second principal component explains 9% of the total variance and reflects variability of the El Ni??o-Southern Oscillation (ENSO) and its associated influence on global annual runoff patterns. The third component explains 5% of the total variance and indicates a response of global annual runoff to variability in North Aflantic SSTs. The association between runoff and North Atlantic SSTs may explain an apparent steplike change in runoff that occurred around 1970 for a number of continental regions.

  13. Joint Disorders

    MedlinePlus

    A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, ...

  14. Development of High Temperature Dissimilar Joint Technology for Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Bowman, Cheryl L.; Gabb, Timothy P.

    2009-01-01

    NASA is developing fission surface power (FSP) system technology as a potential option for use on the surface of the moon or Mars. The goal is to design a robust system that takes full advantage of existing materials data bases. One of the key components of the power conversion system is the hot-side Heat Exchanger (HX). One possible design for this heat exchanger requires a joint of the dissimilar metals 316L stainless steel and Inconel 718, which must sustain extended operation at high temperatures. This study compares two joining techniques, brazing and diffusion bonding, in the context of forming the requisite stainless steel to superalloy joint. The microstructures produced by brazing and diffusion bonding, the effect of brazing cycle on the mechanical tensile properties of the alloys, and the strength of several brazed joints will be discussed.

  15. Gender Dimorphic ACL Strain In Response to Combined Dynamic 3D Knee Joint Loading: Implications for ACL Injury Risk

    PubMed Central

    Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.

    2009-01-01

    While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897

  16. Relationship between maximum isometric joint moment and functional task performance in patients with brachial plexus injury: A pilot study.

    PubMed

    Crouch, Dustin L; Santago, Anthony C; Plate, Johannes F; Li, Zhongyu; Saul, Katherine R

    2016-02-01

    We evaluated whether subjects with brachial plexus injury (BPI) adapted their movements to reduce the mechanical demand on their impaired upper extremity. In 6 subjects with unilateral BPI with C5 and C6 involvement, we measured bilateral maximum isometric shoulder and elbow strength, and computed joint kinematics and net muscle-generated joint moments during 7 unimanual functional tasks. Compared to the unimpaired extremity, maximum strength in shoulder abduction, extension, and external rotation was 60% (p=0.02), 49% (p=0.02), and 75% (p=0.02) lower, respectively, on the impaired side. Significant kinematic and kinetic differences were observed only when reaching to the back of the head. However, because of substantially reduced strength in their impaired upper extremities, subjects used a significantly higher percentage of their maximum strength during several tasks and along several directions of movement. The peak percentage of maximal strength subjects used across tasks was 32% (p=0.03) and 29% (p=0.03) more on their impaired side in shoulder extension and external rotation, respectively. Subjects had less reserve strength available for performing upper extremity tasks and, therefore, may be less adaptive to strength declines due to injury progression and normal aging. Quantitatively measuring maximal strength may help clinicians ensure that patients maintain sufficient upper extremity strength to preserve long-term functional ability.

  17. Underestimated Sacroiliac Joint Lesion on Computed Tomography in Pelvic Open-book Injury: A Case Report

    PubMed Central

    Kim, Weon-Yoo; Jeong, Jae-Jung; Kang, Han-Vit

    2016-01-01

    The classification of anteroposterior compression (APC) injury type is based on using static radiographs, stress radiographs are known as a useful adjunct in classifying type of APC pelvic injuries. According to a recent article, the intraoperative stress examination has led to a change in the treatment plan in more than 25% of patients on 22 patients presumed APC type I (symphyseal diastasis <2.5 cm) injuries. Here authors present a case demonstrating a necessity of intraoperative stress test for excluding concealed posterior ring disruption. PMID:27536644

  18. Inferior epigastric artery: Surface anatomy, prevention and management of injury.

    PubMed

    Wong, Clare; Merkur, Harry

    2016-04-01

    The anatomical position of the inferior epigastric artery (IEA) subjects it to risk of injury during abdominal procedures that are close to the artery, such as laparoscopic trocar insertion, insertion of intra-abdominal drains, Tenckhoff(®) catheter (peritoneal dialysis catheter) and paracentesis. This article aims to raise the awareness of the anatomical variations of the course of the IEA in relation to abdominal landmarks in order to define a safer zone for laparoscopic ancillary trocar placement. Methods of managing the IEA injury as well as techniques to minimise the risk of injury to the IEA are reviewed and discussed.

  19. Neural network committees for finger joint angle estimation from surface EMG signals

    PubMed Central

    Shrirao, Nikhil A; Reddy, Narender P; Kosuri, Durga R

    2009-01-01

    Background In virtual reality (VR) systems, the user's finger and hand positions are sensed and used to control the virtual environments. Direct biocontrol of VR environments using surface electromyography (SEMG) signals may be more synergistic and unconstraining to the user. The purpose of the present investigation was to develop a technique to predict the finger joint angle from the surface EMG measurements of the extensor muscle using neural network models. Methodology SEMG together with the actual joint angle measurements were obtained while the subject was performing flexion-extension rotation of the index finger at three speeds. Several neural networks were trained to predict the joint angle from the parameters extracted from the SEMG signals. The best networks were selected to form six committees. The neural network committees were evaluated using data from new subjects. Results There was hysteresis in the measured SMEG signals during the flexion-extension cycle. However, neural network committees were able to predict the joint angle with reasonable accuracy. RMS errors ranged from 0.085 ± 0.036 for fast speed finger-extension to 0.147 ± 0.026 for slow speed finger extension, and from 0.098 ± 0.023 for the fast speed finger flexion to 0.163 ± 0.054 for slow speed finger flexion. Conclusion Although hysteresis was observed in the measured SEMG signals, the committees of neural networks were able to predict the finger joint angle from SEMG signals. PMID:19154615

  20. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2015-10-01

    patient will go on to develop this condition. There are no effective screening methods to determine who is at risk. This proposal includes both a...after moderate to severe articular injuries, not every patient will go on to develop this condition. There are no effective screening methods to...articular injuries, not every patient will go on to develop this condition. Currently, there are no effective screening methods to determine who is at risk

  1. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post-Traumatic Arthritis

    DTIC Science & Technology

    2015-10-01

    every patient will go on to develop this condition. There are no effective screening methods to determine who is at risk. This proposal includes both...discharged soldiers.3 While PTA can occur rapidly after moderate to severe articular injuries, not every patient will go on to develop this condition. There...the mechanism is not well-understood [1, 2, 3]. While PTA can occur rapidly after moderate to severe articular injuries, not every patient will go on

  2. Joint laminate degradation assessed by reflected ultrasound from the cartilage surface and osteochondral junction

    NASA Astrophysics Data System (ADS)

    Brown, C. P.; Hughes, S. W.; Crawford, R. W.; Oloyede, A.

    2008-08-01

    The ability to quantify and qualify the progression of joint degeneration is becoming increasingly important in surgery. This paper examines the patterns of relative ultrasound reflection from normal, artificially and naturally degraded cartilage-on-bone, particularly investigating the potential of the ratio of reflection coefficients from the surface and osteochondral junction in distinguishing normal from osteoarthritic tissue. To this end, the reflection coefficients from the articular surface and osteochondral junction of normal cartilage-on-bone samples were calculated and compared to samples after the removal of proteoglycans, disruption of the collagen meshwork, delipidization of the articular surface and mechanical abrasion. Our results show that the large variation across normal and degraded joint samples negates the use of an isolated bone reflection measurement and to a lesser extent, an isolated surface reflection. The relative surface to bone reflections, calculated as a ratio of reflection coefficients, provided a more consistent and statistically significant (p < 0.001) method for distinguishing each type of degradation, especially osteoarthritic degradation, and due to the complementary relationship between surface and bone reflections was found to be an effective method for distinguishing degraded from normal tissue in the osteoarthritic joint, independent of the site of initiation of the osteoarthritic process.

  3. Clinical and MRI considerations in sports-related knee joint cartilage injury and cartilage repair.

    PubMed

    Hughes, Richard J; Houlihan-Burne, David G

    2011-02-01

    Cartilage injuries of the knee occur frequently in professional and amateur athletes and can be associated with severe debilitation and morbidity. They are commonly associated with ligament injuries but also may be frequently isolated. Increasing awareness and advances in magnetic resonance imaging (MRI) have led to increasing diagnosis and recognition of these injuries. Articular cartilage is just 2 to 4 mm thick and is avascular, alymphatic, and aneural. It has a limited capacity for healing, and there has been increasing use of cartilage repair techniques to treat these lesions in the active population. Strategies for cartilage repair include marrow stimulation techniques such as microfracture/drilling, osteochondral grafting, and autologous chondrocyte transplants. MRI is an important tool in the diagnosis and grading of cartilage injury and is useful in the follow-up and monitoring of these repair procedures. It is important for radiologists and clinicians to be aware of the capabilities and limitations of MRI in assessing cartilage injury and to be familiar with common postsurgical appearances to facilitate assessment and follow-up in this population. This article reviews the clinical findings and MRI imaging appearances of cartilage injury. The management options are discussed as well as common postsurgical appearances following the various interventions.

  4. Compartment Syndrome Following Arthroscopic Removal of a Bullet in the Knee Joint after a Low-Velocity Gunshot Injury.

    PubMed

    Keskinbora, Mert; Yalçin, Sercan; Oltulu, İsmail; Erdil, Mehmet Emin; Örmeci, Tuğrul

    2016-03-01

    Gunshot injuries are getting more frequently reported while the civilian (nongovernmental) armament increases in the world. A 42-year-old male patient presented to emergency room of Istanbul Medipol University Hospital due to a low-velocity gunshot injury. We detected one entry point on the posterior aspect of the thigh, just superior to the popliteal groove. No exit wound was detected on his physical examination. There was swelling around the knee and range of motion was limited due to pain and swelling. Neurological and vascular examinations were intact. Following the initial assessment, the vascular examination was confirmed by doppler ultrasonography of the related extremity. There were no signs of compartment syndrome in the preoperative physical examination. A bullet was detected in the knee joint on the initial X-rays. Immediately after releasing the tourniquet, swelling of the anterolateral compartment of the leg and pulse deficiency was detected on foot in the dorsalis pedis artery. Although the arthroscopic removal of intra-articular bullets following gunshot injuries seems to have low morbidity rates, it should always be considered that the articular capsule may have been ruptured and the fluids used during the operation may leak into surrounding tissues and result in compartment syndrome.

  5. Compartment Syndrome Following Arthroscopic Removal of a Bullet in the Knee Joint after a Low-Velocity Gunshot Injury

    PubMed Central

    Yalçin, Sercan; Oltulu, İsmail; Erdil, Mehmet Emin; Örmeci, Tuğrul

    2016-01-01

    Gunshot injuries are getting more frequently reported while the civilian (nongovernmental) armament increases in the world. A 42-year-old male patient presented to emergency room of Istanbul Medipol University Hospital due to a low-velocity gunshot injury. We detected one entry point on the posterior aspect of the thigh, just superior to the popliteal groove. No exit wound was detected on his physical examination. There was swelling around the knee and range of motion was limited due to pain and swelling. Neurological and vascular examinations were intact. Following the initial assessment, the vascular examination was confirmed by doppler ultrasonography of the related extremity. There were no signs of compartment syndrome in the preoperative physical examination. A bullet was detected in the knee joint on the initial X-rays. Immediately after releasing the tourniquet, swelling of the anterolateral compartment of the leg and pulse deficiency was detected on foot in the dorsalis pedis artery. Although the arthroscopic removal of intra-articular bullets following gunshot injuries seems to have low morbidity rates, it should always be considered that the articular capsule may have been ruptured and the fluids used during the operation may leak into surrounding tissues and result in compartment syndrome. PMID:26929809

  6. The joint use of the tangential electric field and surface Laplacian in EEG classification.

    PubMed

    Carvalhaes, C G; de Barros, J Acacio; Perreau-Guimaraes, M; Suppes, P

    2014-01-01

    We investigate the joint use of the tangential electric field (EF) and the surface Laplacian (SL) derivation as a method to improve the classification of EEG signals. We considered five classification tasks to test the validity of such approach. In all five tasks, the joint use of the components of the EF and the SL outperformed the scalar potential. The smallest effect occurred in the classification of a mental task, wherein the average classification rate was improved by 0.5 standard deviations. The largest effect was obtained in the classification of visual stimuli and corresponded to an improvement of 2.1 standard deviations.

  7. Simultaneous segmentation of the bone and cartilage surfaces of a knee joint in 3D

    NASA Astrophysics Data System (ADS)

    Yin, Y.; Zhang, X.; Anderson, D. D.; Brown, T. D.; Hofwegen, C. Van; Sonka, M.

    2009-02-01

    We present a novel framework for the simultaneous segmentation of multiple interacting surfaces belonging to multiple mutually interacting objects. The method is a non-trivial extension of our previously reported optimal multi-surface segmentation. Considering an example application of knee-cartilage segmentation, the framework consists of the following main steps: 1) Shape model construction: Building a mean shape for each bone of the joint (femur, tibia, patella) from interactively segmented volumetric datasets. Using the resulting mean-shape model - identification of cartilage, non-cartilage, and transition areas on the mean-shape bone model surfaces. 2) Presegmentation: Employment of iterative optimal surface detection method to achieve approximate segmentation of individual bone surfaces. 3) Cross-object surface mapping: Detection of inter-bone equidistant separating sheets to help identify corresponding vertex pairs for all interacting surfaces. 4) Multi-object, multi-surface graph construction and final segmentation: Construction of a single multi-bone, multi-surface graph so that two surfaces (bone and cartilage) with zero and non-zero intervening distances can be detected for each bone of the joint, according to whether or not cartilage can be locally absent or present on the bone. To define inter-object relationships, corresponding vertex pairs identified using the separating sheets were interlinked in the graph. The graph optimization algorithm acted on the entire multiobject, multi-surface graph to yield a globally optimal solution. The segmentation framework was tested on 16 MR-DESS knee-joint datasets from the Osteoarthritis Initiative database. The average signed surface positioning error for the 6 detected surfaces ranged from 0.00 to 0.12 mm. When independently initialized, the signed reproducibility error of bone and cartilage segmentation ranged from 0.00 to 0.26 mm. The results showed that this framework provides robust, accurate, and

  8. An investigation into the effect of varying joint aperture and nature of surface on pre-splitting

    SciTech Connect

    Tariq, S.M.; Worsey, P.N.

    1996-12-01

    Presplitting is now a universally accepted perimeter control technique in rock excavation. The success of presplitting and the smoothness and integrity of the resulting perimeter is largely dependent on the nature of joints in any given formation. Many facets of jointing have been previously investigated. The results of the effects of joints frequency and spatial positioning were presented by the authors at the ISEE annual meeting last year. This paper includes the results of further research into the mechanism of presplit blasting being carried out at the Rock Mechanics and Explosives Research Center of the University of Missouri-Rolla. The results of experimental model testing carried out in concrete blocks are presented. The research comprised of modeling both closed and open joints between 3/8 inch blastholes loaded with 15-grain per foot PETN detonating cord. The closed joints were (a) simple (rough) machine-cut and (b) surface ground (smooth-matching). The precision ground joints were modeled to simulate tight fractures as found in real rock mass. Precision spacers of varying thicknesses were used to create opening between the joint surfaces. It was found that precision ground joints have no significant effect on the maximum blasthole spacing up to two joints, and act like a continuous medium. This is because ground surfaces provide a relatively perfect match thereby transmitting most of the energy through the joint. However beyond two ground joints, the effects of attenuation is evident and the maximum blasthole spacing has to be reduced to obtain a presplit plane. A simple machine cut joint, on the other hand, has some undulations that results in loss of energy, making it necessary to bring the blastholes closer to achieve a presplit plane (for up to two joints). It was observed that a ground joint with spacer thickness of 0.012 inch behaves like a free surface.

  9. Association of the type of trauma, occurrence of bone bruise, fracture and joint effusion with the injury to the menisci and ligaments in MRI of knee trauma

    PubMed Central

    Pezeshki, Sina; Vogl, Thomas J.; Pezeshki, Mohammad Zakaria; Daghighi, Mohammad Hossein; Pourisa, Masoud

    2016-01-01

    Summary Background magnetic resonance imaging (MRI) as a noninvasive diagnostic tool may help clinicians in the evaluation of injuries to menisci and ligaments. Purpose this study assessed the associations between type of trauma to knee joint, bone bruise, fracture and pathological joint effusion with injuries to menisci and ligaments of knee joint. Methods we reviewed knee joint MRI of 175 patients aged less than 45 years old who were referred to MRI center of our University. Results statistical analysis showed that tearing of medial meniscus (MM) is significantly more common in sport related trauma (p= 0.045) but tearing of medial collateral ligament (MCL) is significantly more common in non-sport related trauma (p= 0.005). Existence of bone bruise in knee MRI is negatively associated with tearing of medial meniscus (MM) (p=0.004) and positively associated with tearing of anterior cruciate ligament (ACL) (p=0.00047) and medial collateral ligament (MCL) (p = 0.0001). Existence of fracture is associated with decreased risk of the tearing of ACL and MM (p=0.04, p=0.001 respectively). Pathologic joint effusion is significantly more common in ACL and MCL tearing (p=0.0001, p=0.004 respectively). Conclusions as diagnostic clues, bone bruise, fracture and joint effusion may help radiologists for better assessment of injury to menisci and ligaments in MRI of patients with knee trauma. PMID:27331046

  10. Development Of an Experimental Animal Model For Lower Back Pain By Percutaneous Injury-Induced Lumbar Facet Joint Osteoarthritis

    PubMed Central

    Kim, Jae-Sung; Ahmadinia, Kasra; Li, Xin; Hamilton, John L; Andrews, Steven; Haralampus, Chris A.; Xiao, Guozhi; Sohn, Hong-Moon; You, Jae-Won; Seo, Yo-Seob; Stein, Gary S.; Wijnen, Andre J Van; Kim, Su-Gwan; Im, Hee-Jeong

    2015-01-01

    We report generation and characterization of pain-related behavior in a minimally-invasive facet joint degeneration (FJD) animal model in rats. FJD was produced by a non-open percutaneous puncture-induced injury on the right lumbar FJs at three consecutive levels. Pressure hyperalgesia in the lower back was assessed by measuring the vocalization response to pressure from a force transducer. After hyperalgesia was established, pathological changes in lumbar FJs and alterations of intervertebral foramen size were assessed by histological and imaging analyses. To investigate treatment options for lumber FJ osteoarthritis-induced pain, animals with established hyperalgesia were administered with analgesic drugs, such as morphine, a selective COX-2 inhibitor, a non-steroidal anti-inflammatory drug (NSAID) (ketorolac), or pregabalin. Effects were assessed by behavioral pain responses. One week after percutaneous puncture-induced injury of the lumbar FJs, ipsilateral primary pressure hyperalgesia developed and was maintained for at least 12 weeks without foraminal stenosis. Animals showed decreased spontaneous activity, but no secondary hyperalgesia in the hind paws. Histopathological and microfocus X-ray computed tomography analyses demonstrated that the percutaneous puncture injury resulted in osteoarthritis-like structural changes in the FJs cartilage and subchondral bone. Pressure hyperalgesia was completely reversed by morphine. The administration of celecoxib produced moderate pain reduction with no statistical significance while the administration of ketorolac and pregabalin produced no analgesic effect on FJ osteoarthritis-induced back pain. Our animal model of non-open percutanous puncture-induced injury of the lumbar FJs in rats shows similar characteristics of low back pain produced by human facet arthropathy. PMID:25858171

  11. Regenerative Medicine and Restoration of Joint Function

    DTIC Science & Technology

    2014-12-01

    joint replacement are used to treat a joint with an intra-articular fracture or destroyed by a combat injury. Generation of personalized, anatomically...knee joint disrupted either by an intra-articular fracture or trauma. Being able to generate personalized implants is a critical feature given that...compression testing to determine tensile strength. Fracture cleavage surfaces were analyzed using scanning electron microscopy. The effects of the

  12. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    DOE PAGES

    Syracuse, E. M.; Maceira, M.; Zhang, H.; ...

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks ofmore » both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.« less

  13. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    SciTech Connect

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.

  14. Design of a surface replacement prosthesis for the proximal interphalangeal joint.

    PubMed

    Ash, H E; Unsworth, A

    2000-01-01

    A surface replacement finger joint prosthesis was designed specifically for the proximal interphalangeal joint (PIPJ). The two-piece design consisted of a bi-condylar proximal phalangeal head and a conforming bi-concave middle phalangeal base. The bearing surfaces were designed as close to the original anatomy of the PIPJs as possible, using detailed information obtained from a previous anatomical study of 83 PIPJs by the present authors. Four sizes of prosthesis were designed with maximum head diameters of 7, 8, 9 and 10 mm. Fixation of the joint prosthesis was achieved by an interference fit between the stems of semicircular cross-section and the phalangeal bone shafts. The main considerations for the stem designs were the offset from the centre of rotation, angle of inclination, length, and cross-sectional shape and size. It is proposed that the two components will be made from cross-linked polyethylene (XLPE) because it can be injection moulded to produce the complex shapes of the joint prosthesis. In addition, XLPE against itself has shown comparable wear rates with stainless steel against ultra-high molecular weight polyethylene from previous work by Joyce et al.

  15. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    NASA Astrophysics Data System (ADS)

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-01

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm. The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs data sets indicate that the results of these types of joint inversions must be interpreted carefully.

  16. Joint inversion of high-frequency surface waves with fundamental and higher modes

    USGS Publications Warehouse

    Luo, Y.; Xia, J.; Liu, J.; Liu, Q.; Xu, S.

    2007-01-01

    Joint inversion of multimode surface waves for estimating the shear (S)-wave velocity has received much attention in recent years. In this paper, we first analyze sensitivity of phase velocities of multimodes of surface waves for a six-layer earth model, and then we invert surface-wave dispersion curves of the theoretical model and a real-world example. Sensitivity analysis shows that fundamental mode data are more sensitive to the S-wave velocities of shallow layers and are concentrated on a very narrow frequency band, while higher mode data are more sensitive to the parameters of relatively deeper layers and are distributed over a wider frequency band. These properties provide a foundation of using a multimode joint inversion to define S-wave velocities. Inversion results of both synthetic data and a real-world example demonstrate that joint inversion with the damped least-square method and the singular-value decomposition technique to invert high-frequency surface waves with fundamental and higher mode data simultaneously can effectively reduce the ambiguity and improve the accuracy of S-wave velocities. ?? 2007.

  17. Successful treatment of a guitarist with a finger joint injury using instrument-assisted soft tissue mobilization: a case report

    PubMed Central

    Terry Loghmani, M.; Bayliss, Amy J.; Clayton, Greg; Gundeck, Evelina

    2015-01-01

    Finger injuries are common and can greatly affect a musician’s quality of life. A 55-year-old man, who had injured the proximal interphalangeal joint of the left index finger 6 months prior to any intervention, was treated with a manual therapy approach incorporating instrument-assisted soft tissue mobilization (IASTM). Initial examination findings included self-reported pain and functional limitations and physical impairments that significantly impeded his ability to play the acoustic guitar. He was treated once a week for 6 weeks with IASTM, joint mobilization, therapeutic exercise, and ice massage. Additionally, a home exercise program and self-care instructions were provided. The patient gained positive outcomes with improvements in pain (Numerical Pain Rating Scale while playing the guitar: initial 5/10, discharge 1/10) and function (Disability Arm Shoulder Hand Sports-Performing Arts Optional Module: initial 75; discharge 6·25), each reaching a minimum clinically important difference. Importantly, he was able to play the guitar with minimal to no pain as desired. Physical measures also improved, including an immediate gain in finger range of motion with IASTM alone. Manual therapy approaches integrating IASTM may provide an effective conservative treatment strategy for patients with finger/hand conditions in the performing arts and other patient populations. PMID:26952165

  18. Successful treatment of a guitarist with a finger joint injury using instrument-assisted soft tissue mobilization: a case report.

    PubMed

    Terry Loghmani, M; Bayliss, Amy J; Clayton, Greg; Gundeck, Evelina

    2015-12-01

    Finger injuries are common and can greatly affect a musician's quality of life. A 55-year-old man, who had injured the proximal interphalangeal joint of the left index finger 6 months prior to any intervention, was treated with a manual therapy approach incorporating instrument-assisted soft tissue mobilization (IASTM). Initial examination findings included self-reported pain and functional limitations and physical impairments that significantly impeded his ability to play the acoustic guitar. He was treated once a week for 6 weeks with IASTM, joint mobilization, therapeutic exercise, and ice massage. Additionally, a home exercise program and self-care instructions were provided. The patient gained positive outcomes with improvements in pain (Numerical Pain Rating Scale while playing the guitar: initial 5/10, discharge 1/10) and function (Disability Arm Shoulder Hand Sports-Performing Arts Optional Module: initial 75; discharge 6·25), each reaching a minimum clinically important difference. Importantly, he was able to play the guitar with minimal to no pain as desired. Physical measures also improved, including an immediate gain in finger range of motion with IASTM alone. Manual therapy approaches integrating IASTM may provide an effective conservative treatment strategy for patients with finger/hand conditions in the performing arts and other patient populations.

  19. Effectiveness of surgical reconstruction to restore radiocarpal joint mechanics after scapholunate ligament injury: an in vivo modeling study.

    PubMed

    Johnson, Joshua E; Lee, Phil; McIff, Terence E; Toby, E Bruce; Fischer, Kenneth J

    2013-05-31

    Disruption of the scapholunate ligament can cause a loss of normal scapholunate mechanics and eventually lead to osteoarthritis. Surgical reconstruction attempts to restore scapholunate relationship show improvement in functional outcomes, but postoperative effectiveness in restoring normal radiocarpal mechanics still remains a question. The objective of this study was to investigate the benefits of surgical repair by observing changes in contact mechanics on the cartilage surface before and after surgical treatment. Six patients with unilateral scapholunate dissociation were enrolled in the study, and displacement driven magnetic resonance image-based surface contact modeling was used to investigate normal, injured and postoperative radiocarpal mechanics. Model geometry was acquired from images of wrists taken in a relaxed position. Kinematics were acquired from image registration between the relaxed images, and images taken during functional loading. Results showed a trend for increase in radiocarpal contact parameters with injury. Peak and mean contact pressures significantly decreased after surgery in the radiolunate articulation and there were no significant differences between normal and postoperative wrists. Results indicated that surgical repair improves contact mechanics after injury and that contact mechanics can be surgically restored to be similar to normal. This study provides novel contact mechanics data on the effects of surgical repair after scapholunate ligament injury. With further work, it may be possible to more effectively differentiate between treatments and degenerative changes based on in vivo contact mechanics data.

  20. Joint analysis of refractions with surface waves: An inverse solution to the refraction-traveltime problem

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Xia, J.; Steeples, D.; Park, C.B.

    2006-01-01

    We describe a possible solution to the inverse refraction-traveltime problem (IRTP) that reduces the range of possible solutions (nonuniqueness). This approach uses a reference model, derived from surface-wave shear-wave velocity estimates, as a constraint. The application of the joint analysis of refractions with surface waves (JARS) method provided a more realistic solution than the conventional refraction/tomography methods, which did not benefit from a reference model derived from real data. This confirmed our conclusion that the proposed method is an advancement in the IRTP analysis. The unique basic principles of the JARS method might be applicable to other inverse geophysical problems. ?? 2006 Society of Exploration Geophysicists.

  1. Design, fabrication and test of graphite/polyimide composite joints and attachments. [spacecraft control surfaces

    NASA Technical Reports Server (NTRS)

    Cushman, J. B.; Mccleskey, S. F.; Ward, S. H.

    1982-01-01

    The design, analysis, and testing performed to develop four types of graphite/polyimide (Gr/PI) bonded and bolted composite joints for lightly loaded control surfaces on advanced space transportation systems that operate at temperatures up to 561 K (550 F) are summarized. Material properties and small specimen tests were conducted to establish design data and to evaluate specific design details. Static discriminator tests were conducted on preliminary designs to verify structural adequacy. Scaled up specimens of the final joint designs, representative of production size requirements, were subjected to a series of static and fatigue tests to evaluate joint strength. Effects of environmental conditioning were determined by testing aged (125 hours at 589 K (600 F)) and thermal cycled (116 K to 589 K (-250 F to 600 F), 125 times) specimens. It is concluded Gr/PI joints can be designed and fabricated to carry the specified loads. Test results also indicate a possible resin loss or degradation of laminates after exposure to 589 K (600 F) for 125 hours.

  2. Structural tests and development of a laminar flow control wing surface composite chordwise joint

    NASA Technical Reports Server (NTRS)

    Lineberger, L. B.

    1984-01-01

    The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program beginning in 1976 to develop technologies to improve fuel efficiency. The Lockheed-Georgia Company accomplished under NAS1-16235 Laminar-Flow-Control (LFC) Wing Panel Structural Design and Development (WSSD); design, manufacturing, and testing activities. An in-depth preliminary design of the baseline 1993 LFC wing was accomplished. A surface panel using the Lockheed graphite/epoxy integrated LFC wing box structural concept was designed. The concept was shown by analysis to be structurally efficient and cost effective. Critical details of the surface and surface joint was demonstrated by fabricating and testing complex, concept selection specimens. The Lockheed-Georgia Company accomplishments, Development of LFC Wind Surface Composite Structures (WSCS), are documented. Tests were conducted on two CV2 panels to verify the static tension and fatigue strength of LFC wing surface chordwise joints.

  3. Evaluation of near-surface stress distributions in dissimilar welded joint by scanning acoustic microscopy.

    PubMed

    Kwak, Dong Ryul; Yoshida, Sanichiro; Sasaki, Tomohiro; Todd, Judith A; Park, Ik Keun

    2016-04-01

    This paper presents the results from a set of experiments designed to ultrasonically measure the near surface stresses distributed within a dissimilar metal welded plate. A scanning acoustic microscope (SAM), with a tone-burst ultrasonic wave frequency of 200 MHz, was used for the measurement of near surface stresses in the dissimilar welded plate between 304 stainless steel and low carbon steel. For quantitative data acquisition such as leaky surface acoustic wave (leaky SAW) velocity measurement, a point focus acoustic lens of frequency 200 MHz was used and the leaky SAW velocities within the specimen were precisely measured. The distributions of the surface acoustic wave velocities change according to the near-surface stresses within the joint. A three dimensional (3D) finite element simulation was carried out to predict numerically the stress distributions and compare with the experimental results. The experiment and FE simulation results for the dissimilar welded plate showed good agreement. This research demonstrates that a combination of FE simulation and ultrasonic stress measurements using SAW velocity distributions appear promising for determining welding residual stresses in dissimilar material joints.

  4. Comparative study on isokinetic capacity of knee and ankle joints by functional injury

    PubMed Central

    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability. PMID:26957768

  5. Surface grafting of artificial joints with a biocompatible polymer for preventing periprosthetic osteolysis

    NASA Astrophysics Data System (ADS)

    Moro, Toru; Takatori, Yoshio; Ishihara, Kazuhiko; Konno, Tomohiro; Takigawa, Yorinobu; Matsushita, Tomiharu; Chung, Ung-Il; Nakamura, Kozo; Kawaguchi, Hiroshi

    2004-11-01

    Periprosthetic osteolysis-bone loss in the vicinity of a prosthesis-is the most serious problem limiting the longevity of artificial joints. It is caused by bone-resorptive responses to wear particles originating from the articulating surface. This study investigated the effects of graft polymerization of our original biocompatible phospholipid polymer 2-methacryloyloxyethyl phosphorylcholine (MPC) onto the polyethylene surface. Mechanical studies using a hip-joint simulator revealed that the MPC grafting markedly decreased the friction and the amount of wear. Osteoclastic bone resorption induced by subperiosteal injection of particles onto mouse calvariae was abolished by the MPC grafting on particles. MPC-grafted particles were shown to be biologically inert by culture systems with respect to phagocytosis and resorptive cytokine secretion by macrophages, subsequent expression of receptor activator of NF-κB ligand in osteoblasts, and osteoclastogenesis from bone marrow cells. From the mechanical and biological advantages, we believe that our approach will make a major improvement in artificial joints by preventing periprosthetic osteolysis.

  6. Macroscopic Surface Structures for Polymer-metal Hybrid Joints Manufactured by Laser Based Thermal Joining

    NASA Astrophysics Data System (ADS)

    Schricker, Klaus; Stambke, Martin; Bergmann, Jean Pierre; Bräutigam, Kevin; Henckell, Philipp

    The increasing application of hybrid structures in component design and fabrication allows to constantly enhance the realization of lightweight potentials. Laser-based joining of metals to polymers can obtaina local bonding with high load bearing capability. During the process, the polymer gets molten by the energy input of the laser beam and penetrates into the structure of the metal surface by means of a defined joining pressure. Macroscopic structures on the metal surface, produced by cutting or laser processing, are possible surface treatmentsfor achieving thepolymer-metal joints. The optimal geometry and other key parameters for the macroscopic surface structures are only partially known at present, e.g. a rising structure density causes a higher load capacity. Based on grooves and drilled holes, as referencegeometries, the depth (0.1-0.9 mm), width (0.3-1.1 mm), alignment angle, diameter (1.0mm- 1.5mm), structure density and penetration depth of the molten polymer were correlated to the separation force. The results allow an essential insight into the main effects ofmacroscopic structures on the mechanical joint properties and the material performance of the polymer during the process.

  7. Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries.

    PubMed

    Thali, Michael J; Braun, Marcel; Dirnhofer, Richard

    2003-11-26

    Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.

  8. Effect of Plasma Surface Finish on Wettability and Mechanical Properties of SAC305 Solder Joints

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung-Ho; Koike, Junichi; Yoon, Jeong-Won; Yoo, Sehoon

    2016-12-01

    The wetting behavior, interfacial reactions, and mechanical reliability of Sn-Ag-Cu solder on a plasma-coated printed circuit board (PCB) substrate were evaluated under multiple heat-treatments. Conventional organic solderability preservative (OSP) finished PCBs were used as a reference. The plasma process created a dense and highly cross-linked polymer coating on the Cu substrates. The plasma finished samples had higher wetting forces and shorter zero-cross times than those with OSP surface finish. The OSP sample was degraded after sequential multiple heat treatments and reflow processes, whereas the solderability of the plasma finished sample was retained after multiple heat treatments. After the soldering process, similar microstructures were observed at the interfaces of the two solder joints, where the development of intermetallic compounds was observed. From ball shear tests, it was found that the shear force for the plasma substrate was consistently higher than that for the OSP substrate. Deterioration of the OSP surface finish was observed after multiple heat treatments. Overall, the plasma surface finish was superior to the conventional OSP finish with respect to wettability and joint reliability, indicating that it is a suitable material for the fabrication of complex electronic devices.

  9. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    SciTech Connect

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-30

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying material requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  10. The surface geometry of inherited joint and fracture trace patterns resulting from active and passive deformation

    NASA Technical Reports Server (NTRS)

    Podwysocki, M. H.; Gold, D. P.

    1974-01-01

    Hypothetical models are considered for detecting subsurface structure from the fracture or joint pattern, which may be influenced by the structure and propagated to the surface. Various patterns of an initially orthogonal fracture grid are modeled according to active and passive deformation mechanisms. In the active periclinal structure with a vertical axis, fracture frequency increased both over the dome and basin, and remained constant with decreasing depth to the structure. For passive periclinal features such as a reef or sand body, fracture frequency is determined by the arc of curvature and showed a reduction over the reefmound and increased over the basin.

  11. Verification of the effect of surface preparation on Hot Isostatic Pressing diffusion bonding joints of CLAM steel

    NASA Astrophysics Data System (ADS)

    Zhao, Yanyun; Li, Chunjing; Huang, Bo; Liu, Shaojun; Huang, Qunying

    2014-12-01

    Hot Isostatic Pressing (HIP) diffusion bonding with CLAM steel is the primary candidate fabrication technique for the first wall (FW) of DFLL-TBM. Surface state is one of the key factors for the joints quality. The effect of surface state prepared with grinder and miller on HIP diffusion bonding joints of CLAM steel was investigated. HIP diffusion bonding was performed at 140 MPa and 1373 K within 3 h. The mechanical properties of the joints were investigated with instrumented Charpy V-notch impact tests and the microstructures of the joints were analyzed with scanning electron microscopy (SEM). The results showed that the milled samples with fine surface roughness were more suitable for CLAM steel HIP diffusion bonding.

  12. Dysbiosis in Crohn's disease - Joint action of stochastic injuries and focal inflammation in the gut

    PubMed Central

    Buttó, Ludovica F.; Haller, Dirk

    2017-01-01

    ABSTRACT Gut homeostasis involves interrelated biological networks that include the immune system, specialized cells of the epithelium, such as Paneth and goblet cells, as well as triggers derived from the microbiota. Disruption of these homeostatic interactions may lead to the pathogenesis of inflammatory bowel diseases (IBD). To develop more targeted and individual treatments in Crohn's disease and ulcerative colitis, it becomes more and more important to link key mechanisms of the disease pathogenesis to distinct IBD subsets. For the first time, our laboratory demonstrated a causal role of the microbiota for the development of Crohn's disease (CD)-like ileitis, supporting the hypothesis that a non-infectious, dysbiotic microbial ecosystem harbors aggressive traits relevant for the induction of chronic inflammation in the disease-susceptible host (i.e. TNFΔARE mouse model). Despite a growing body of evidence claiming a primary role for Paneth cells in the pathogenesis of ileal CD, we showed in the TNFΔARE mouse model that Paneth cell failure or exhaustion is a secondary event to inflammation. Therefore, additional mechanisms may act synergistically to initialize the development of CD-like pathology. Hereby, we propose a novel hypothesis suggesting that individual development of dysbiotic communities is based on stochastic injury and focal inflammation of the epithelial lining that propagate radially, finally leading to an aggressive microbial milieu. PMID:28102757

  13. Crustal structure of North Dakota from joint inversion of surface wave dispersion and teleseismic P-wave reciever functions

    NASA Astrophysics Data System (ADS)

    Walsh, Braden Michael

    Studying and determining crustal structure of the Earth is important for understanding the interior of the Earth. Using methods like receiver functions and surface wave dispersion allows the determination of differences in structure and composition through the crust. Jointly inverting receiver functions and surface wave dispersion reduces the error and over-interpretation of the crustal structure estimation. Receiver functions and surface wave dispersion invert well together because receiver functions are very sensitive to velocity contrasts and vertical travel times, and surface wave dispersion is sensitive to average velocity and insensitive to sharp velocity contrasts. By jointly inverting receiver functions and surface wave dispersion, shear wave velocity profiles can be created to determine the properties of the crustal structure and velocity contrasts. With the use of IRIS Transportable Array stations data throughout the United States, this thesis takes a closer look at the crustal structure of North Dakota through the joint inversion of surface wave dispersion and teleseismic P-wave receiver functions. The receiver functions in North Dakota show shallow sediment effects that affect the joint inversion process. In western North Dakota the Williston basin and in eastern North Dakota the Red River Valley cause ringing effects in the receiver functions. The shallow sediments in North Dakota control and overpower the rest of the crustal signal in the receiver functions, and thus affect the ability of determining the crustal shear wave velocity structure of North Dakota through the joint inversion of receiver functions and surface wave dispersion, thus the use of background geology is necessary.

  14. Ligament Injury, Reconstruction and Osteoarthritis

    PubMed Central

    Fleming, Braden C.; Hulstyn, Michael J.; Oksendahl, Heidi L.; Fadale, Paul D.

    2007-01-01

    Purpose of Review The recent literature on the factors that initiate and accelerate the progression of osteoarthritis following ligament injuries and their treatment is reviewed. Recent Findings The ligament-injured joint is at high risk for osteoarthritis. Current conservative (e.g. rehabilitation) and surgical (e.g. reconstruction) treatment options appear not to reduce osteoarthritis following ligament injury. The extent of osteoarthritis does not appear dependent on which joint is affected, or the presence of damage to other tissues within the joint. Mechanical instability is the likely initiator of osteoarthritis in the ligament-injured patient. Summary The mechanism osteoarthritis begins with the injury rendering the joint unstable. The instability increases the sliding between the joint surfaces and reduces the efficiency of the muscles, factors that alter joint contact mechanics. The load distribution in the cartilage and underlying bone is disrupted, causing wear and increasing shear, which eventually leads to the osteochondral degeneration. The catalyst to the mechanical process is the inflammation response induced by the injury and sustained during healing. In contrast, the inflammation could be responsible for onset, while the mechanical factors accelerate progression. The mechanisms leading to osteoarthritis following ligament injury have not been fully established. A better understanding of these mechanisms should lead to alternative surgical, drug, and tissue-engineering treatment options, which could eliminate osteoarthritis in these patients. Progress is being made on all fronts. Considering that osteoarthritis is likely to occur despite current treatment options, the best solution may be prevention. PMID:17710194

  15. The effects of road-surface conditions, age, and gender on driver-injury severities.

    PubMed

    Morgan, Abigail; Mannering, Fred L

    2011-09-01

    Drivers' adaptation to weather-induced changes in roadway-surface conditions is a complex process that can potentially be influenced by many factors including age and gender. Using a mixed logit analysis, this research assesses the effects that age, gender, and other factors have on crash severities by considering single-vehicle crashes that occurred on dry, wet, and snow/ice-covered roadway surfaces. With an extensive database of single-vehicle crashes from Indiana in 2007 and 2008, estimation results showed that there were substantial differences across age/gender groups under different roadway-surface conditions. For example, for all females and older males, the likelihood of severe injuries increased when crashes occurred on wet or snow/ice surfaces-but for male drivers under 45 years of age, the probability of severe injuries decreased on wet and snow/ice surfaces - relative to dry-surface crashes. This and many other significant differences among age and gender groups suggest that drivers perceive and react to pavement-surface conditions in very different ways, and this has important safety implications. Furthermore, the empirical findings of this study highlight the value of considering subsets of data to unravel the complex relationships within crash-injury severity analysis.

  16. Exploring Caregiver Behavior and Knowledge about Unsafe Sleep Surfaces in Infant Injury Death Cases

    ERIC Educational Resources Information Center

    Chu, Tracy; Hackett, Martine; Kaur, Navpreet

    2015-01-01

    Objectives: In the United States, infant deaths due to sleep-related injuries have quadrupled over the past two decades. One of the major risk factors is the placement of an infant to sleep on a surface other than a crib or bassinet. This study examines contextual circumstances and knowledge and behaviors that may contribute to the placement of…

  17. Ultrasonic detection technology based on joint robot on composite component with complex surface

    SciTech Connect

    Hao, Juan; Xu, Chunguang; Zhang, Lan

    2014-02-18

    Some components have complex surface, such as the airplane wing and the shell of a pressure vessel etc. The quality of these components determines the reliability and safety of related equipment. Ultrasonic nondestructive detection is one of the main methods used for testing material defects at present. In order to improve the testing precision, the acoustic axis of the ultrasonic transducer should be consistent with the normal direction of the measured points. When we use joint robots, automatic ultrasonic scan along the component surface normal direction can be realized by motion trajectory planning and coordinate transformation etc. In order to express the defects accurately and truly, the robot position and the signal of the ultrasonic transducer should be synchronized.

  18. Joint effects of illumination geometry and object shape in the perception of surface reflectance

    PubMed Central

    Olkkonen, Maria; Brainard, David H

    2011-01-01

    Surface properties provide useful information for identifying objects and interacting with them. Effective utilization of this information, however, requires that the perception of object surface properties be relatively constant across changes in illumination and changes in object shape. Such constancy has been studied separately for changes in these factors. Here we ask whether the separate study of the illumination and shape effects is sufficient, by testing whether joint effects of illumination and shape changes can be predicted from the individual effects in a straightforward manner. We found large interactions between illumination and object shape in their effects on perceived glossiness. In addition, analysis of luminance histogram statistics could not account for the interactions. PMID:23145259

  19. Functional anatomy of the equine temporomandibular joint: Collagen fiber texture of the articular surfaces.

    PubMed

    Adams, K; Schulz-Kornas, E; Arzi, B; Failing, K; Vogelsberg, J; Staszyk, C

    2016-11-01

    In the last decade, the equine masticatory apparatus has received much attention. Numerous studies have emphasized the importance of the temporomandibular joint (TMJ) in the functional process of mastication. However, ultrastructural and histological data providing a basis for biomechanical and histopathological considerations are not available. The aim of the present study was to analyze the architecture of the collagen fiber apparatus in the articular surfaces of the equine TMJ to reveal typical morphological features indicating biomechanical adaptions. Therefore, the collagen fiber alignment was visualized using the split-line technique in 16 adult warmblood horses without any history of TMJ disorders. Within the central two-thirds of the articular surfaces of the articular tubercle, the articular disc and the mandibular head, split-lines ran in a correspondent rostrocaudal direction. In the lateral and medial aspects of these articular surfaces, the split-line pattern varied, displaying curved arrangements in the articular disc and punctual split-lines in the bony components. Mediolateral orientated split-lines were found in the rostral and caudal border of the articular disc and in the mandibular fossa. The complex movements during the equine chewing cycle are likely assigned to different areas of the TMJ. The split-line pattern of the equine TMJ is indicative of a relative movement of the joint components in a preferential rostrocaudal direction which is consigned to the central aspects of the TMJ. The lateral and medial aspects of the articular surfaces provide split-line patterns that indicate movements particularly around a dorsoventral axis.

  20. Lithological and Surface Geometry Joint Inversions Using Multi-Objective Global Optimization Methods

    NASA Astrophysics Data System (ADS)

    Lelièvre, Peter; Bijani, Rodrigo; Farquharson, Colin

    2016-04-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based minimum-structure geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy may be to consider two fundamentally different types of inversions: lithological and surface geometry inversions. A major advantage of these two inversion approaches is that joint inversion of multiple types of geophysical data is greatly simplified. In a lithological inversion, the subsurface is discretized into a mesh and each cell contains a particular rock type. A lithological model must be translated to a physical property model before geophysical data simulation. Each lithology may map to discrete property values or there may be some a priori probability density function associated with the mapping. Through this mapping, lithological inverse problems limit the parameter domain and consequently reduce the non-uniqueness from that presented by standard mesh-based inversions that allow physical property values on continuous ranges. Furthermore, joint inversion is greatly simplified because no additional mathematical coupling measure is required in the objective function to link multiple physical property models. In a surface geometry inversion, the model comprises wireframe surfaces representing contacts between rock units. This parameterization is then fully consistent with Earth models built by geologists, which in 3D typically comprise wireframe contact surfaces of tessellated triangles. As for the lithological case, the physical properties of the units lying between the contact

  1. Adhesive-Bonded Composite Joint Analysis with Delaminated Surface Ply Using Strain-Energy Release Rate

    NASA Technical Reports Server (NTRS)

    Chadegani, Alireza; Yang, Chihdar; Smeltzer, Stanley S. III

    2012-01-01

    This paper presents an analytical model to determine the strain energy release rate due to an interlaminar crack of the surface ply in adhesively bonded composite joints subjected to axial tension. Single-lap shear-joint standard test specimen geometry with thick bondline is followed for model development. The field equations are formulated by using the first-order shear-deformation theory in laminated plates together with kinematics relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. The system of second-order differential equations is solved to using the symbolic computation tool Maple 9.52 to provide displacements fields. The equivalent forces at the tip of the prescribed interlaminar crack are obtained based on interlaminar stress distributions. The strain energy release rate of the crack is then determined by using the crack closure method. Finite element analyses using the J integral as well as the crack closure method are performed to verify the developed analytical model. It has been shown that the results using the analytical method correlate well with the results from the finite element analyses. An attempt is made to predict the failure loads of the joints based on limited test data from the literature. The effectiveness of the inclusion of bondline thickness is justified when compared with the results obtained from the previous model in which a thin bondline and uniform adhesive stresses through the bondline thickness are assumed.

  2. High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.

    2007-01-01

    Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying materia1 requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.

  3. Surface curvature of pelvic joints from three laser scanners: separating anatomy from measurement error.

    PubMed

    Villa, Chiara; Gaudio, Daniel; Cattaneo, Cristina; Buckberry, Jo; Wilson, Andrew S; Lynnerup, Niels

    2015-03-01

    Recent studies have reported that quantifying symphyseal and auricular surface curvature changes on 3D models acquired by laser scanners has a potential for age estimation. However, no tests have been carried out to evaluate the repeatability of the results between different laser scanners. 3D models of the two pelvic joints were generated using three laser scanners (Custom, Faro, and Minolta). The surface curvature, the surface area, and the distance between co-registered meshes were investigated. Close results were found for surface areas (differences between 0.3% and 2.4%) and for distance deviations (average <20 μm, SD <200 μm). The curvature values were found to be systematically biased between different laser scanners, but still showing similar trends with increasing phases/scores. Applying a smoothing factor to the 3D models, it was possible to separate anatomy from the measurement error of each instrument, so that similar curvature values could be obtained (p < 0.05) independent of the specific laser scanner.

  4. Histopathological findings, phenotyping of inflammatory cells, and expression of markers of nitritative injury in joint tissue samples from calves after vaccination and intraarticular challenge with Mycoplasma bovis strain 1067

    PubMed Central

    2014-01-01

    Background The pathogenesis of caseonecrotic lesions developing in lungs and joints of calves infected with Mycoplasma bovis is not clear and attempts to prevent M. bovis-induced disease by vaccines have been largely unsuccessful. In this investigation, joint samples from 4 calves, i.e. 2 vaccinated and 2 non-vaccinated, of a vaccination experiment with intraarticular challenge were examined. The aim was to characterize the histopathological findings, the phenotypes of inflammatory cells, the expression of class II major histocompatibility complex (MHC class II) molecules, and the expression of markers for nitritative stress, i.e. inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), in synovial membrane samples from these calves. Furthermore, the samples were examined for M. bovis antigens including variable surface protein (Vsp) antigens and M. bovis organisms by cultivation techniques. Results The inoculated joints of all 4 calves had caseonecrotic and inflammatory lesions. Necrotic foci were demarcated by phagocytic cells, i.e. macrophages and neutrophilic granulocytes, and by T and B lymphocytes. The presence of M. bovis antigens in necrotic tissue lesions was associated with expression of iNOS and NT by macrophages. Only single macrophages demarcating the necrotic foci were positive for MHC class II. Microbiological results revealed that M. bovis had spread to approximately 27% of the non-inoculated joints. Differences in extent or severity between the lesions in samples from vaccinated and non-vaccinated animals were not seen. Conclusions The results suggest that nitritative injury, as in pneumonic lung tissue of M. bovis-infected calves, is involved in the development of caseonecrotic joint lesions. Only single macrophages were positive for MHC class II indicating down-regulation of antigen-presenting mechanisms possibly caused by local production of iNOS and NO by infiltrating macrophages. PMID:25162202

  5. The joint effect of surface microtopography and near-surface structure on microcontact conditions

    SciTech Connect

    McCool, J.I.

    1989-01-01

    Pin-on-disk tests are now complete on all 27 ceramic Phase I specimens. The relationship between measured pin wear and both mean asperity flash temperature and mean real contact stress is examined for the subset of tests that was run at high sliding speed. Fracture indentation tests were completed at the University of Michigan on a second set of 9 ceramic specimens. The last set of nine specimens for indentation testing have been delivered to the University of Michigan. A total of 45 hardened M50 high alloy steel disks have been coated with WC, TiC and TiN and comprehensive surface roughness measurements have been made. A number of 3/8 in. diameter balls have been similarly coated. These balls will serve as the pin element in pin-on-disk tests to be performed at ORNL. Nonlinear curve fits were made to a series of correction factors that account for the presence of a coating in computing the load and area of spherical asperities. The fitted functions have been incorporated into a simulation model for analyzing the behavior of coated asperities. Example calculations are given for a steel substrate with the coating modulus spanning the range from 1/10 to 10 times the substrate modulus. 3 figs., 3 tabs.

  6. LIDAR-based outcrop characterisation - joint classification, surface and block size distribution

    NASA Astrophysics Data System (ADS)

    Tanner, David C.; Dietrich, Patrick; Krawczyk, Charlotte M.

    2013-04-01

    Outcrops, in the first instance, only offer at best a 2-2.5D view of the available geological information, such as joints and fractures. In order to study geodynamic processes, it is necessary to calculate true values of, for example, fracture densities and block dimensions. We show how LIDAR-generated point-cloud data of outcrops can be used to delineate such geological surfaces. Our methods do not require the point-set to be meshed; instead we work with the original point cloud, thus avoiding meshing errors. In a first step we decompose the point-cloud into tiny volumes; in each volume we calculate the best fitting plane. An expert can then decide which of the planes are important (in an interactive density pole diagram) and classify them. Actual block surfaces are identified by applying a clustering algorithm to the mini-planes. Subsequently, we calculate the size of these surfaces. Finally we estimate the block size distribution within the outcrop by projecting the block surfaces into the rock volume. To assess the reproducibility of our results we show to which extent they depend on various parameters, such as the resolution of the LIDAR scan and algorithm parameters. In theory the results can be calculated at the site of measurement to ensure the LIDAR scan resolution is sufficient and if necessary rerun the scan with different parameters. We demonstrate our methods with LIDAR data that we produced in a sandstone quarry in Germany. The part of the outcrop which we measured with the LIDAR was out-of-reach for measurements with a geological compass, but our results correlate well with compass measurements from a different outcrop in the same quarry. Three main surfaces could be delineated from the point cloud: the bedding, and two major joint types. The three fabrics are almost orthogonal. Our statistical results suggest that blocks with a volume of several hundred liters can be expected regularly within the quarry. The results can be directly used to

  7. Adaptive dynamic surface control of flexible-joint robots using self-recurrent wavelet neural networks.

    PubMed

    Yoo, Sung Jin; Park, Jin Bae; Choi, Yoon Ho

    2006-12-01

    A new method for the robust control of flexible-joint (FJ) robots with model uncertainties in both robot dynamics and actuator dynamics is proposed. The proposed control system is a combination of the adaptive dynamic surface control (DSC) technique and the self-recurrent wavelet neural network (SRWNN). The adaptive DSC technique provides the ability to overcome the "explosion of complexity" problem in backstepping controllers. The SRWNNs are used to observe the arbitrary model uncertainties of FJ robots, and all their weights are trained online. From the Lyapunov stability analysis, their adaptation laws are induced, and the uniformly ultimately boundedness of all signals in a closed-loop adaptive system is proved. Finally, simulation results for a three-link FJ robot are utilized to validate the good position tracking performance and robustness against payload uncertainties and external disturbances of the proposed control system.

  8. The influence of hand positions on biomechanical injury risk factors at the wrist joint during the round-off skills in female gymnastics.

    PubMed

    Farana, Roman; Jandacka, Daniel; Uchytil, Jaroslav; Zahradnik, David; Irwin, Gareth

    2017-01-01

    The aim of this study was to examine the biomechanical injury risk factors at the wrist, including joint kinetics, kinematics and stiffness in the first and second contact limb for parallel and T-shape round-off (RO) techniques. Seven international-level female gymnasts performed 10 trials of the RO to back handspring with parallel and T-shape hand positions. Synchronised kinematic (3D motion analysis system; 247 Hz) and kinetic (two force plates; 1235 Hz) data were collected for each trial. A two-way repeated measure analysis of variance (ANOVA) assessed differences in the kinematic and kinetic parameters between the techniques for each contact limb. The main findings highlighted that in both the RO techniques, the second contact limb wrist joint is exposed to higher mechanical loads than the first contact limb demonstrated by increased axial compression force and loading rate. In the parallel technique, the second contact limb wrist joint is exposed to higher axial compression load. Differences between wrist joint kinetics highlight that the T-shape technique may potentially lead to reducing these bio-physical loads and consequently protect the second contact limb wrist joint from overload and biological failure. Highlighting the biomechanical risk factors facilitates the process of technique selection making more objective and safe.

  9. Proximal interphalangeal joint dimensions for the design of a surface replacement prosthesis.

    PubMed

    Ash, H E; Unsworth, A

    1996-01-01

    The bones from 83 proximal interphalangeal joints (PIPJs) were dissected in order to determine the shape and size of the articular surfaces. The bones were modelled in acrylic dental bone cement and the original bones and replicas were then sectioned and shadowgraphed. Dimensions were taken from these shadowgraphs to be used in the design of a surface replacement prosthesis for the PIPJ. It was found that the bi-condylar heads of the proximal and middle phalanges were circular in the sagittal plane as was the base of the middle phalanx. However, the radius of curvature of the middle phalangeal base was greater than that of the proximal phalangeal head indicating that the PIPJ is not a conforming joint. The alignment of the radial and ulnar condyles of the proximal phalangeal bones was investigated and it was found that the index and middle finger bones tended to have a more prominent ulnar condyle while the ring and little finger bones tended to have a more prominent radial condyle. This was due to a slight difference in diameters of the two condyles. The proximal phalangeal bone lengths L ranged from 29-52 mm, maximum head widths W from 8.5-15.5 mm and maximum diameters D of the best-fit circles to the sagittal profile of the bone head from 6-11 mm. The middle phalangeal bone lengths ranged from 16-35 mm, maximum head widths from 8.5-12 mm and maximum diameters from 5-7.5 mm. The relationships and ratios between these dimensions for the proximal and middle phalanges have been calculated.

  10. Joint Traveltime and Waveform Envelope Inversion for Near-surface Imaging

    NASA Astrophysics Data System (ADS)

    Liu, Zhiyang; Zhang, Jie

    2016-12-01

    In the linearized seismic full waveform inversion (FWI), it is well known that a good initial model is needed to avoid cycle-skipping issue, especially when the low-frequency components of data are lacking. To solve the problem, we develop a joint first-arrival traveltime and early arrival envelope inversion method (JTE) to build a good near-surface velocity model with low-wavenumber components. The JTE method combines the robustness of nonlinear traveltime inversion and the low-frequency information embedded in the waveform envelope. In two synthetic experiments, we confirm that traveltime inversion constrains the top near-surface velocity structures tightly, while the envelope inversion recovers the low-wavenumber structures with low-velocity objects or layers. Using the results of JTE as starting models, we find that FWI can produce accurate solutions for complex numerical models. In a real-data example, JTE followed by FWI resolves a near-surface velocity model to improve statics corrections for the subsurface stacking image.

  11. Joint Traveltime and Waveform Envelope Inversion for Near-surface Imaging

    NASA Astrophysics Data System (ADS)

    Liu, Zhiyang; Zhang, Jie

    2017-03-01

    In the linearized seismic full waveform inversion (FWI), it is well known that a good initial model is needed to avoid cycle-skipping issue, especially when the low-frequency components of data are lacking. To solve the problem, we develop a joint first-arrival traveltime and early arrival envelope inversion method (JTE) to build a good near-surface velocity model with low-wavenumber components. The JTE method combines the robustness of nonlinear traveltime inversion and the low-frequency information embedded in the waveform envelope. In two synthetic experiments, we confirm that traveltime inversion constrains the top near-surface velocity structures tightly, while the envelope inversion recovers the low-wavenumber structures with low-velocity objects or layers. Using the results of JTE as starting models, we find that FWI can produce accurate solutions for complex numerical models. In a real-data example, JTE followed by FWI resolves a near-surface velocity model to improve statics corrections for the subsurface stacking image.

  12. The Potential for Brain Injury on Selected Surfaces Used by Cheerleaders

    PubMed Central

    Shields, Brenda J.; Smith, Gary A.

    2009-01-01

    Abstract Context: Although playground surfaces have been investigated for fall impact attenuation, the surfaces that cheerleaders use have received little attention. Objective: To determine (1) the critical height for selected surfaces used by cheerleaders at or below which a serious head impact injury from a fall is unlikely to occur, (2) the critical heights for non–impact-absorbing surfaces for comparison purposes, and (3) the effect of soil moisture and grass height on gmax (which is defined as the multiple of g [acceleration due to gravity at the earth's surface at sea level: ie, 32.2 feet·s−1·s−1] that represents the maximum deceleration experienced during an impact) and the Head Injury Criterion (HIC) at the critical height for a dry grass surface. Design: Observational study. Settings: A local cheerleading gym, indoor locations within the authors' institution, and various outdoor locations. Main Outcome Measure(s): gmax, HIC, and critical height. Results: Critical heights for the surfaces tested ranged from 0.5 ft (0.15 m) for concrete and vinyl tile installed over concrete to more than 11 ft (3.35 m) for a spring floor. Increases in grass height and soil moisture resulted in an increase in the critical height for grass surfaces. Only spring floors and 4-in (0.10-m)–thick landing mats placed on traditional foam floors had critical heights greater than 10.5 ft (3.20 m), thus providing enough impact-absorbing capacity for performance of 2-level stunts. Conclusions: The potential for serious head impact injuries can be minimized by increasing the shock-absorbing capacity of the surface, decreasing the height from which the person falls, or both. Cheerleaders and cheerleading coaches should use the critical heights reported in this study to compare the relative impact-absorbing capacities of the various surfaces tested, with critical height as an indicator of the impact-absorption capacity of the surface. The findings of this study can be used to

  13. [Joint prostheses components of warm-forged and surface treated Ti-6Al-7Nb alloy].

    PubMed

    Semlitsch, M; Weber, H; Streicher, R M; Schön, R

    1991-05-01

    In 1978 development of a TiAl alloy with the inert alloying element niobium was initiated. In 1984, the optimal composition was found to be Ti-6Al-7Nb (Protasul-100). This custom-made alloy for implants has the same alpha/beta micro-structure and equally good mechanical properties as Ti-6Al-4V. The corrosion resistance of Ti-6Al-7Nb is better than that of pure titanium and Ti-6Al-4V, due to the very dense and stable passive layer. Since 1985, highly stressed anchoring stems of various hip prosthesis designs have been manufactured from hot-forged Ti-6Al-7Nb/Protasul-100. Polished surfaces of hip, knee or wrist joints made of Ti-6Al-7Nb intended to articulate with polyethylene are surface-treated by the application of a very hard, 3-5 microns thick titanium nitride coating (Tribosul-TiN), or by oxygen diffusion hardening (Tribosul-ODH) to a depth of 30 microns.

  14. Joint inversion of surface wave dispersion and receiver functions for crustal structure in Oklahoma

    NASA Astrophysics Data System (ADS)

    Guo, Hao

    The surge in seismicity in Oklahoma starting in 2008 raises questions about the actual locations of the earthquakes in the upper crust. The key to answering this is an improved crustal model that explains as many observations as possible. Love and Rayleigh wave dispersion, teleseismic P-wave receiver functions and some unique transverse motions observed at distances less than 100 km that are characteristics of rays reverberating in a basin provide data to derive the crustal model. The surface wave dispersion data set consists of over 300,000 Love/Rayleigh phase/group values obtained from ambient noise cross-correlation of BH channels of the 133 Transportable Array (TA) stations of Earthscope to periods as short as 2 seconds. Station coverage is dense enough to perform the tomography on a 25*25 km grid that should be able to image shallow geological structures. In addition, receiver functions were obtained using teleseismic data recorded from 3 US Geological Survey Networks (GS) stations and 6 Oklahoma Seismic Network (OK) stations from 2011 to 2014. The 1-D S-wave velocity models derived by the joint inversion of surface wave dispersion and receiver functions with geological constraints are tested by fitting the independent transverse seismograms. This test also provides constraints on the earthquake depths in relation to the geological structure.

  15. Comparison of regression models for estimation of isometric wrist joint torques using surface electromyography

    PubMed Central

    2011-01-01

    Background Several regression models have been proposed for estimation of isometric joint torque using surface electromyography (SEMG) signals. Common issues related to torque estimation models are degradation of model accuracy with passage of time, electrode displacement, and alteration of limb posture. This work compares the performance of the most commonly used regression models under these circumstances, in order to assist researchers with identifying the most appropriate model for a specific biomedical application. Methods Eleven healthy volunteers participated in this study. A custom-built rig, equipped with a torque sensor, was used to measure isometric torque as each volunteer flexed and extended his wrist. SEMG signals from eight forearm muscles, in addition to wrist joint torque data were gathered during the experiment. Additional data were gathered one hour and twenty-four hours following the completion of the first data gathering session, for the purpose of evaluating the effects of passage of time and electrode displacement on accuracy of models. Acquired SEMG signals were filtered, rectified, normalized and then fed to models for training. Results It was shown that mean adjusted coefficient of determination (Ra2) values decrease between 20%-35% for different models after one hour while altering arm posture decreased mean Ra2 values between 64% to 74% for different models. Conclusions Model estimation accuracy drops significantly with passage of time, electrode displacement, and alteration of limb posture. Therefore model retraining is crucial for preserving estimation accuracy. Data resampling can significantly reduce model training time without losing estimation accuracy. Among the models compared, ordinary least squares linear regression model (OLS) was shown to have high isometric torque estimation accuracy combined with very short training times. PMID:21943179

  16. The influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite Rugby Union.

    PubMed

    Williams, S; Trewartha, G; Kemp, S P T; Michell, R; Stokes, K A

    2016-01-01

    This prospective cohort study investigated the influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite English Premiership Rugby Union players. Time loss (from 39.5 matches) and abrasion (from 27 matches) injury risk was compared between matches played on artificial turf and natural grass. Muscle soreness was reported over the 4 days following one match played on each surface by 95 visiting players (i.e., normally play on natural grass surfaces). There was a likely trivial difference in the overall injury burden relating to time-loss injuries between playing surfaces [rate ratio = 1.01, 90% confidence interval (CI): 0.73-1.38]. Abrasions were substantially more common on artificial turf (rate ratio = 7.92, 90% CI: 4.39-14.28), although the majority of these were minor and only two resulted in any reported time loss. Muscle soreness was consistently higher over the 4 days following a match on artificial turf in comparison with natural grass, although the magnitude of this effect was small (effect sizes ranging from 0.26 to 0.40). These results suggest that overall injury risk is similar for the two playing surfaces, but further surveillance is required before inferences regarding specific injury diagnoses and smaller differences in overall injury risk can be made.

  17. Emerging options for treatment of articular cartilage injury in the athlete.

    PubMed

    Mithoefer, Kai; McAdams, Timothy R; Scopp, Jason M; Mandelbaum, Bert R

    2009-01-01

    Articular cartilage injury is observed with increasing frequency in both elite and amateur athletes and results from the significant joint stress associated particularly with high-impact sports. The lack of spontaneous healing of these joint surface defects leads to progressive joint pain and mechanical symptoms with resulting functional impairment and limitation of athletic participation. Left untreated, articular cartilage defects can lead to chronic joint degeneration and athletic disability. Articular cartilage repair in athletes requires effective and durable joint surface restoration that can withstand the significant joint stresses generated during athletic activity. Several techniques for articular cartilage repair have been developed recently, which can successfully restore articular cartilage surfaces and allow for return to high-impact athletics after articular cartilage injury. Besides these existing techniques, new promising scientific concepts and techniques are emerging that incorporate modern tissue engineering technologies and promise further improvement for the treatment of these challenging injuries in the demanding athletic population.

  18. Severe injury of bilateral elbow joints with unilateral terrible triad of the elbow and unilateral suspected terrible triad of the elbow complicated with olecranon fracture: one case report

    PubMed Central

    Zha, Guoqing; Niu, Xiaofeng; Yu, Weiguang; Xiao, Liangbao

    2015-01-01

    Terrible triad of the elbow is characterized as posterior dislocation of the elbow joint accompanied by the fractures of the radial head and coronoid process of the ulna, which is rarely seen in clinical practice, especially because the mild fracture is barely detected by imaging method In this study, we reported one case of serious complex bilateral elbow injury, presenting with unilateral typical terrible triad of the elbow and suspected terrible triad of the elbow complicated with olecranon fracture on the other side. Clinical experience was obtained during the diagnosis and treatment procedures. PMID:26550399

  19. A rare combined injury of dorsal fracture-dislocation of four carpometacarpal joints and trapezium, trapezoid and distal radius bone fractures.

    PubMed

    Touloupakis, Georgios; Stuflesser, Wilfried; Antonini, Guido; Ferrara, Fabrizio; Crippa, Cornelio; Lettera, Maria Gabriella

    2016-05-06

    Incorrect or delayed diagnosis and treatment of the carpometacarpal fracture-dislocations is often associated with poor prognosis. We present a rare case of unusual pattern of injury, involving dorsal dislocation of four ulnar carpometacarpal joints, associated with fracture of the trapezium, a burst fracture of the trapezoid  bone and an extra-articular fracture of the third distal  of the radius. The first surgical intervention was followed by unsatisfactory results, confirmed by the CT scans. A second surgery followed and an open reduction and pinning with K wires performed. Post-operative follow up lasting for nine months revealed a very good surgical outcome.

  20. Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

    USGS Publications Warehouse

    Carlson, D.

    2010-01-01

    Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77??E and N37??E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8??, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  1. Subspace based adaptive denoising of surface EMG from neurological injury patients

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Ying, Dongwen; Zev Rymer, William; Zhou, Ping

    2014-10-01

    Objective: After neurological injuries such as spinal cord injury, voluntary surface electromyogram (EMG) signals recorded from affected muscles are often corrupted by interferences, such as spurious involuntary spikes and background noises produced by physiological and extrinsic/accidental origins, imposing difficulties for signal processing. Conventional methods did not well address the problem caused by interferences. It is difficult to mitigate such interferences using conventional methods. The aim of this study was to develop a subspace-based denoising method to suppress involuntary background spikes contaminating voluntary surface EMG recordings. Approach: The Karhunen-Loeve transform was utilized to decompose a noisy signal into a signal subspace and a noise subspace. An optimal estimate of EMG signal is derived from the signal subspace and the noise power. Specifically, this estimator is capable of making a tradeoff between interference reduction and signal distortion. Since the estimator partially relies on the estimate of noise power, an adaptive method was presented to sequentially track the variation of interference power. The proposed method was evaluated using both semi-synthetic and real surface EMG signals. Main results: The experiments confirmed that the proposed method can effectively suppress interferences while keep the distortion of voluntary EMG signal in a low level. The proposed method can greatly facilitate further signal processing, such as onset detection of voluntary muscle activity. Significance: The proposed method can provide a powerful tool for suppressing background spikes and noise contaminating voluntary surface EMG signals of paretic muscles after neurological injuries, which is of great importance for their multi-purpose applications.

  2. Lithospheric structure beneath northern Mississippi embayment from joint inversion of surface wave dispersion and receiver functions

    NASA Astrophysics Data System (ADS)

    Su, Han

    The northern Mississippi Embayment is characterized by relatively high seismicity at the New Madrid Seismic Zone. Although many studies have focused on specific earthquakes or on the structure at specific locations, the mechanism of the earthquake process has remained an enigma. As part of the Northern Embayment Lithosphere Experiment, we focus on high resolution surface-wave tomography of Love and Rayleigh, phase and group velocities for a study region bounded by 34-40 N latitude and 85-94 W longitude for periods from 2 to 50 seconds by cross-correlating ambient noise from BH channels of the Transportable Array of EarthScope. To test the usefulness of the dispersion, we perform a joint inversion of dispersion and teleseismic P-wave receiver functions for stations in the region. At a few locations, we are able to test the resulting models by comparing predicted to observed broadband recordings of local earthquakes. At these few locations, we find good agreement and also evidence that the Moho is a gradient rather than a sharp discontinuity.

  3. Surface electromyographic assessment of patients with long lasting temporomandibular joint disorder pain.

    PubMed

    Tartaglia, Gianluca M; Lodetti, Gianluigi; Paiva, Guiovaldo; De Felicio, Claudia Maria; Sforza, Chiarella

    2011-08-01

    The normalized electromyographic characteristics of masticatory muscles in patients with temporomandibular joint disorders (TMD) and healthy controls were compared. Thirty TMD patients (15 men, 15 women, mean age 23 years) with long lasting pain (more than 6 months), and 20 control subjects matched for sex and age were examined. All patients had arthrogenous TMD according to the Research Diagnostic Criteria for TMD (RDC/TMD). Surface electromyography of masseter and temporal muscles was performed during maximum teeth clenching either on cotton rolls or in intercuspal position. Standardized EMG indices and the median power frequency were obtained, and compared between the two groups and sexes using ANOVAs. During clenching, the TMD patients had larger asymmetry in their temporalis muscles, larger temporalis activity relative to masseter, and reduced mean power frequencies than the control subjects (p<0.05, ANOVA). In both groups, the mean power frequencies of the temporalis muscles were larger than those of the masseter muscles (p<0.001). No sex related differences, and no sex × group interactions were found. In conclusion, young adult patients with long lasting TMD have an increased and more asymmetric standardized activity of their temporalis anterior muscle, and reduced mean power frequencies, relative to healthy controls.

  4. Joint spatiotemporal variability of global sea surface temperatures and global Palmer drought severity index values

    USGS Publications Warehouse

    Apipattanavis, S.; McCabe, G.J.; Rajagopalan, B.; Gangopadhyay, S.

    2009-01-01

    Dominant modes of individual and joint variability in global sea surface temperatures (SST) and global Palmer drought severity index (PDSI) values for the twentieth century are identified through a multivariate frequency domain singular value decomposition. This analysis indicates that a secular trend and variability related to the El Niño–Southern Oscillation (ENSO) are the dominant modes of variance shared among the global datasets. For the SST data the secular trend corresponds to a positive trend in Indian Ocean and South Atlantic SSTs, and a negative trend in North Pacific and North Atlantic SSTs. The ENSO reconstruction shows a strong signal in the tropical Pacific, North Pacific, and Indian Ocean regions. For the PDSI data, the secular trend reconstruction shows high amplitudes over central Africa including the Sahel, whereas the regions with strong ENSO amplitudes in PDSI are the southwestern and northwestern United States, South Africa, northeastern Brazil, central Africa, the Indian subcontinent, and Australia. An additional significant frequency, multidecadal variability, is identified for the Northern Hemisphere. This multidecadal frequency appears to be related to the Atlantic multidecadal oscillation (AMO). The multidecadal frequency is statistically significant in the Northern Hemisphere SST data, but is statistically nonsignificant in the PDSI data.

  5. Effects of a shoulder injury prevention strength training program on eccentric external rotator muscle strength and glenohumeral joint imbalance in female overhead activity athletes.

    PubMed

    Niederbracht, Yvonne; Shim, Andrew L; Sloniger, Mark A; Paternostro-Bayles, Madeline; Short, Thomas H

    2008-01-01

    Imbalance of the eccentrically-activated external rotator cuff muscles versus the concentrically-activated internal rotator cuff muscles is a primary risk factor for glenohumeral joint injuries in overhead activity athletes. Nonisokinetic dynamometer based strength training studies, however, have focused exclusively on resulting concentric instead of applicable eccentric strength gains of the external rotator cuff muscles. Furthermore, previous strength training studies did not result in a reduction in glenoumeral joint muscle imbalance, thereby suggesting that currently used shoulder strength training programs do not effectively reduce the risk of shoulder injury to the overhead activity athlete. Two collegiate women tennis teams, consisting of 12 women, participated in this study throughout their preseason training. One team (n = 6) participated in a 5-week, 4 times a week, external shoulder rotator muscle strength training program next to their preseason tennis training. The other team (n = 6) participated in a comparable preseason tennis training program, but did not conduct any upper body strength training. Effects of this strength training program were evaluated by comparing pre- and posttraining data of 5 maximal eccentric external immediately followed by concentric internal contractions on a Kin-Com isokinetic dynamometer (Chattecx Corp., Hixson, Tennessee). Overall, the shoulder strength training program significantly increased eccentric external total work without significant effects on concentric internal total work, concentric internal mean peak force, or eccentric external mean peak force. In conclusion, by increasing the eccentric external total exercise capacity without a subsequent increase in the concentric internal total exercise capacity, this strength training program potentially decreases shoulder rotator muscle imbalances and the risk for shoulder injuries to overhead activity athletes.

  6. Observation of the Degradation Characteristics and Scale of Unevenness on Three-dimensional Artificial Rock Joint Surfaces Subjected to Shear

    NASA Astrophysics Data System (ADS)

    Hong, Eun-Soo; Kwon, Tae-Hyuk; Song, Ki-Il; Cho, Gye-Chun

    2016-01-01

    The present study explores the degradation characteristics and scale of unevenness (small-scale roughness) on sheared rock joint surfaces at a low-stress regime. While the degradation characteristics of unevenness and the normal stress are mutually interrelated, an understanding of the degradation patterns of the three-dimensional roughness of rock joints is one of the important components needed to identify asperity failure characteristics and to quantify the role of damaged unevenness in establishing a shear strength model. A series of direct shear tests was performed on three-dimensional artificial rock joint surfaces at different normal stress levels. After shearing, the spatial distributions and statistical parameters of degraded roughness were analysed for the different normal stress levels. The length and area of the degraded zones showed bell-shaped distributions in a logarithmic scale, and the dominant scale (or the most frequently occurring scale) of the damaged asperities (i.e., unevenness) ranged from approximately, 0.5 to 5.0 mm in length and 0.1-10 mm2 in area. This scale of the damaged unevenness was consistent regardless of the level of normal stress. It was also found that the relative area of damaged unevenness on a given joint area, and thus the contribution of the mechanical asperity failure component to shear strength increased as normal stress increased.

  7. Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2005-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials (HazMats) or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) A void duplication of effort in actions required to reduce or eliminate HazMats through joint center cooperation and technology sharing. This project will identify, evaluate and approve alternative surface preparation technologies for use at NASA and Air Force Space Command (AFSPC) installations. Materials and processes will be evaluated with the goal of selecting those processes that will improve corrosion protection at critical systems, facilitate easier maintenance activity, extend maintenance cycles, eliminate flight hardware contamination and reduce the amount of hazardous waste generated. This Joint Test Protocol (JTP) contains the critical requirements and tests necessary to qualify alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel Applications. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of NASA and Air Force Space Command (AFSPC) participants. The Field Test Plan (FTP), entitled Joint Test Protocol for Validation of Alternative Low Emission Surface Preparation/Depainting Technologies for Structural Steel, prepared by ITB, defines the field evaluation and testing requirements for validating alternative surface preparation/depainting technologies and supplements the JTP.

  8. Joint Test Report for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2007-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the NASA Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) Avoid duplication of effort in actions required to reduce or eliminate hazardous materials through joint center cooperation and technology sharing. The objective of this project was to qualify candidate alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel applications at NASA facilities. This project compares the surface preparation/depainting performance of the proposed alternatives to existing surface preparation/depainting systems or standards. This Joint Test Report (JTR) contains the results of testing as per the outlines of the Joint Test Protocol (JTP), Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, and the Field Test Plan (FTP), Field Evaluations Test Plan for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, for critical requirements and tests necessary to qualify alternatives for coating removal systems. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of government and industry participants. This JTR documents the results of the testing as well as any test modifications made during the execution of the project. This JTR is made available as a reference for future pollution prevention endeavors by other NASA Centers, the Department of Defense and commercial users to minimize duplication of effort. The current coating removal processes

  9. Influence of nickel-phosphorus surface roughness on wettability and pores formation in solder joints for high power electronic applications

    NASA Astrophysics Data System (ADS)

    Vivet, L.; Joudrier, A.-L.; Tan, K.-L.; Morelle, J.-M.; Etcheberry, A.; Chalumeau, L.

    2013-12-01

    Electroless nickel-high-phosphorus Ni-P plating is used as substrate coating in the electronic component technology. The ability to minimize pores formation in solder joints and the wettability of the Ni-P layer remain points of investigation. The qualities and the control of the physical and chemical properties of the deposits are essential for the reliability of the products. In this contribution it has been measured how a controlled change of one property of the Ni-P surface, its average roughness, changes the wettability of this surface before soldering completion, at ambient temperature and under ambient air, and how it contribute to change the amount and size of pores inside solder joints, after soldering completion. Before all, observations of the Ni-P surfaces using scanning electron microscopy have been achieved. Then the wettability has been measured through the determination of both the disperse and the polar fractions of the substrate surface tension, based on the measurements of the wetting angle for droplets of four different liquids, under ambient air and at room temperature (classical sessile drop technique). Finally the X-ray micro-radiography measurements of both the area fraction of pores and the size of the largest pore inside the solder joint of dice laser soldered on the studied substrate, using high melting temperature solder (300 °C, PbSnAg) have been achieved. This study clearly demonstrates that both the ability to minimize pores formation in solder joints and the wettability under ambient conditions of the Ni-P substrate decrease and become more variable when its average roughness increases. These effects can be explained considering the Cassie-Baxter model for rough surface wetting behaviour, completed by the model of heterogeneous nucleation and growth for gas bubbles inside a liquid.

  10. Ceramic joints

    DOEpatents

    Miller, Bradley J.; Patten, Jr., Donald O.

    1991-01-01

    Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

  11. Sulforhodamine B interacts with albumin to lower surface tension and protect against ventilation injury of flooded alveoli.

    PubMed

    Kharge, Angana Banerjee; Wu, You; Perlman, Carrie E

    2015-02-01

    In the acute respiratory distress syndrome, alveolar flooding by proteinaceous edema liquid impairs gas exchange. Mechanical ventilation is used as a supportive therapy. In regions of the edematous lung, alveolar flooding is heterogeneous, and stress is concentrated in aerated alveoli. Ventilation exacerbates stress concentrations and injuriously overexpands aerated alveoli. Injury degree is proportional to surface tension, T. Lowering T directly lessens injury. Furthermore, as heterogeneous flooding causes the stress concentrations, promoting equitable liquid distribution between alveoli should, indirectly, lessen injury. We present a new theoretical analysis suggesting that liquid is trapped in discrete alveoli by a pressure barrier that is proportional to T. Experimentally, we identify two rhodamine dyes, sulforhodamine B and rhodamine WT, as surface active in albumin solution and investigate whether the dyes lessen ventilation injury. In the isolated rat lung, we micropuncture a surface alveolus, instill albumin solution, and obtain an area with heterogeneous alveolar flooding. We demonstrate that rhodamine dye addition lowers T, reduces ventilation-induced injury, and facilitates liquid escape from flooded alveoli. In vitro we show that rhodamine dye is directly surface active in albumin solution. We identify sulforhodamine B as a potential new therapeutic agent for the treatment of the acute respiratory distress syndrome.

  12. Platelet-like Nanoparticles: Mimicking Shape, Flexibility, and Surface Biology of Platelets To Target Vascular Injuries

    PubMed Central

    2015-01-01

    Targeted delivery of therapeutic and imaging agents in the vascular compartment represents a significant hurdle in using nanomedicine for treating hemorrhage, thrombosis, and atherosclerosis. While several types of nanoparticles have been developed to meet this goal, their utility is limited by poor circulation, limited margination, and minimal targeting. Platelets have an innate ability to marginate to the vascular wall and specifically interact with vascular injury sites. These platelet functions are mediated by their shape, flexibility, and complex surface interactions. Inspired by this, we report the design and evaluation of nanoparticles that exhibit platelet-like functions including vascular injury site-directed margination, site-specific adhesion, and amplification of injury site-specific aggregation. Our nanoparticles mimic four key attributes of platelets, (i) discoidal morphology, (ii) mechanical flexibility, (iii) biophysically and biochemically mediated aggregation, and (iv) heteromultivalent presentation of ligands that mediate adhesion to both von Willebrand Factor and collagen, as well as specific clustering to activated platelets. Platelet-like nanoparticles (PLNs) exhibit enhanced surface-binding compared to spherical and rigid discoidal counterparts and site-selective adhesive and platelet-aggregatory properties under physiological flow conditions in vitro. In vivo studies in a mouse model demonstrated that PLNs accumulate at the wound site and induce ∼65% reduction in bleeding time, effectively mimicking and improving the hemostatic functions of natural platelets. We show that both the biochemical and biophysical design parameters of PLNs are essential in mimicking platelets and their hemostatic functions. PLNs offer a nanoscale technology that integrates platelet-mimetic biophysical and biochemical properties for potential applications in injectable synthetic hemostats and vascularly targeted payload delivery. PMID:25318048

  13. Micro-optical rotary joint for multichannel communication via a rotating surface

    NASA Astrophysics Data System (ADS)

    Stark, Markus; Rank, Matthias; Schmidt, Michael; Popp, Gregor; Poisel, Hans

    2005-04-01

    Data transmission between rotating and stationary systems, e.g. required for radar antennas or for undersea cable installation ships can be realized with so called rotary joints. For the transmission of several high bit rate optical data channels a micro optical rotary joint is now available which guarantees a dead reliable, low loss transmission for up to 21 parallel single mode channels. The free space transmission in the rotary joint implicates a highly precise collimation of the parallel channels. For this purpose compact two dimensional fiber collimator arrays based on micro lens arrays have been developed. These arrays and the complete opto-mechanical system are designed with the help of tolerance analysis using Monte Carlo simulations. Besides these results also some more information on the behavior and the characteristics of the micro optical rotary joint under real conditions which demonstrate the excellent characteristics of this novel system will be given.

  14. Study of surface bonding imperfection effects on equivalent identified dynamic Young's and shear moduli using a modal based joint identification method

    NASA Astrophysics Data System (ADS)

    Meshki, M. M.; Nobari, A. S.; Nikbin, K.

    2015-02-01

    In this paper the effects of defects on the equivalent identified dynamic Young's and shear moduli of flexible structural adhesive joints have been investigated. Adhesive joints were subjected to initial surface bonding imperfection, in order to simulate the defects. Several debond patterns have been applied artificially on single-lap joint specimens and joint identification process has been performed for both bending and shear modes to see how surface bonding imperfection can affect equivalent identified dynamic Young's and shear moduli of the adhesive. Using a direct modal based method to identify mechanical characteristics of joints has been shown that degradation of the equivalent moduli of debonded joint is correlated to both frequency and mode shapes. The results reveal that debonding is easily detectable in bending modes whereas degradation in shear modes is also correlated to debonding orientation and mode shapes. Three identical specimens have been tested for each case to prove the consistency of the results.

  15. Wear of cross-linked polyethylene against itself: a material suitable for surface replacement of the finger joint.

    PubMed

    Sibly, T F; Unsworth, A

    1991-05-01

    Cross-linking of polyethylene (XLPE) has dramatically improved its properties in industrial applications, and it may also have some application in the field of human joint replacement. Additionally it has the advantage of permitting a lower molecular weight base material to be used, so that components may be injection moulded rather than machined. This study therefore investigates the wear resistance of medical grade cross-linked polyethylene (XLPE), cross-linked by a silane-grafting process, with a molecular weight between cross links of 5430 g mol(-1). This first report investigates the wear resistance of XLPE against itself, because for certain joints, such as the metacarpo-phalangeal joint, the material may have a high enough wear resistance to allow both bearing surfaces to be made from it. Tests were carried out both on a reciprocating pin and plate machine with pins loaded at 10 and 40 N and also on a new finger joint simulator, which simulates the loads applied to and the movements of, the metacarpo-phalangeal joint. An average wear rate of 1.8 x 10(-6) mm3 N-1 m-1 was found (range 0.9-2.75 x 10(-6) mm3 N-1 m-1). This is about six times greater than the wear rate of non-cross-linked ultra high molecular weight polyethylene (UHMWPE) against stainless steel, but for applications with low loading, such as the metacarpo-phalangeal joint, this material is shown to have adequate wear resistance. The coefficient of friction was 0.1, which is similar to that of UHMWPE on stainless steel.

  16. An evaluation of the blind lap joint for the surface mount attachment of chip components

    SciTech Connect

    Vianco, P T; Dal Porto, J F

    1992-01-01

    Blind lap solder joints were used to attach leadless ceramic chip resistors to polyimidequartz circuit boards. Hand soldering and vapor phase reflow techniques were evaluated. The solder was 62Sn-36Pb-2Ag (wt.%). The integrity of the solder joints was assessed by microstructural examination and room temperature shear tests. These analyses were performed on as-fabricated circuit boards as well as an those samples exposed to thermal cycling (308 cycles; {minus}55{degree} to 125{degree}C; 6{degree}C/min ramps; 120 min hold periods;) or thermal shock (100 cycles, {minus}55{degree}C to 125{degree}C; liquid-to-liquid transfer; 10 min hold periods). In all cases, microscopy revealed no cracks within the solder joints. The shear strengths of the joints were 13.4 lb (59 N), as-fabricated; 10.5 lb (47 N), 308 thermal cycles; and 14.0 lb (62 N), 100 thermal shock cycles. All values were well within acceptability limits for the particular application. Measurements of the intermetallic compound thicknesses at the copper land/solder interface indicated that the additional heating cycle of the hand soldering step decreased the layer thickness as compared to non-hand soldered joints. The successful implementation of the blind lap joint can provide increased device densities on circuit boards by reducing bonding pad extension beyond the ceramic chip foot print.

  17. Jointly deriving NMR surface relaxivity and pore size distributions by NMR relaxation experiments on partially desaturated rocks

    NASA Astrophysics Data System (ADS)

    Mohnke, O.; Hughes, B.

    2014-06-01

    Nuclear magnetic resonance (NMR) relaxometry is a geophysical method widely used in borehole and laboratory applications to nondestructively infer transport and storage properties of rocks and soils as it is directly sensitive to the water/oil content and pore sizes. However, for inferring pore sizes, NMR relaxometry data need to be calibrated with respect to a surface interaction parameter, surface relaxivity, which depends on the type and mineral constituents of the investigated rock. This study introduces an inexpensive and quick alternative to the classical calibration methods, e.g., mercury injection, pulsed field gradient (PFG) NMR, or grain size analysis, which allows for jointly estimating NMR surface relaxivity and pore size distributions using NMR relaxometry data from partially desaturated rocks. Hereby, NMR relaxation experiments are performed on the fully saturated sample and on a sample partially drained at a known differential pressure. Based on these data, the (capillary) pore radius distribution and surface relaxivity are derived by joint optimization of the Brownstein-Tarr and the Young-Laplace equation assuming parallel capillaries. Moreover, the resulting pore size distributions can be used to predict water retention curves. This inverse modeling approach—tested and validated using NMR relaxometry data measured on synthetic porous borosilicate samples with known petrophysical properties (i.e., permeability, porosity, inner surfaces, pore size distributions)—yields consistent and reproducible estimates of surface relaxivity and pore radii distributions. Also, subsequently calculated water retention curves generally correlate well with measured water retention curves.

  18. Are movement disorders and sensorimotor injuries pathologic synergies? When normal multi-joint movement synergies become pathologic.

    PubMed

    Santello, Marco; Lang, Catherine E

    2014-01-01

    The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system's ability to control movement.

  19. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-01-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  20. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-03-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  1. Whiplash injuries.

    PubMed

    Malanga, Gerard; Peter, Jason

    2005-10-01

    Whiplash injuries are very common and usually are associated with rear-end collisions. However, a whiplash injury can be caused by any event that results in hyperextension and flexion of the cervical spine. These injuries are of serious concern to all consumers due to escalating cost of diagnosis, treatment, insurance, and litigation. Most acute whiplash injury cases respond well to conservative treatments, which result in resolution of symptoms usually within weeks to a few months after the injury occurred. Chronic whiplash injuries often are harder to diagnose and treat and often result in poor outcomes. Current research shows that various structures in the cervical spine receive nociceptive innervation and potentially may be the cause of chronic pain symptoms. One potential pain generator showing promise is the facet or zygapophyseal joints. Various researchers have proven that these joints are injured during whiplash injuries and that diagnosis and temporary pain relief can be obtained with facet joint injections. The initial evaluation of any patient should follow an organized and stepwise approach, and more serious causes of neck pain must first be ruled out through the history, physical examination, and diagnostic testing. Treatment regimens should be evidence-based, focusing on treatments that have proven to be effective in treating acute and chronic whiplash injuries.

  2. Surface anatomy of the inferior epigastric artery in relation to laparoscopic injury.

    PubMed

    Epstein, J; Arora, A; Ellis, H

    2004-07-01

    The inferior epigastric artery (IEA) is at risk of injury in laparoscopic surgery. Current descriptions of the course of the IEA do not provide surface landmarks useful to the surgeon. This study aimed to define surface relations and propose guidelines for safer trocar placement. The posterior surfaces of the anterior abdominal walls of 30 preserved cadavers were dissected. The surface anatomy of 60 IEAs and their branches were defined. At the level of the anterior superior iliac spine (ASIS), the IEA is 38% +/- 18% (95% confidence interval [CI]) from the midline to the ASIS. At the mid-inguinal point the relation is 40% +/- 17% and at the umbilicus 40% +/- 22%. The pattern of branches is highly variable. Although giving guidelines for trocar insertion can be treacherous, we found the following to be of value: 1) the midline is avascular; 2) the main stem of the IEA will be avoided if trocars are inserted more than two-thirds of the distance along a horizontal line between the midline and the ASIS; and 3) IEA branches are least frequently found in the lowest part of the abdomen lateral to the artery.

  3. Short- and long-term changes in joint co-contraction associated with motor learning as revealed from surface EMG.

    PubMed

    Osu, Rieko; Franklin, David W; Kato, Hiroko; Gomi, Hiroaki; Domen, Kazuhisa; Yoshioka, Toshinori; Kawato, Mitsuo

    2002-08-01

    In the field of motor control, two hypotheses have been controversial: whether the brain acquires internal models that generate accurate motor commands, or whether the brain avoids this by using the viscoelasticity of musculoskeletal system. Recent observations on relatively low stiffness during trained movements support the existence of internal models. However, no study has revealed the decrease in viscoelasticity associated with learning that would imply improvement of internal models as well as synergy between the two hypothetical mechanisms. Previously observed decreases in electromyogram (EMG) might have other explanations, such as trajectory modifications that reduce joint torques. To circumvent such complications, we required strict trajectory control and examined only successful trials having identical trajectory and torque profiles. Subjects were asked to perform a hand movement in unison with a target moving along a specified and unusual trajectory, with shoulder and elbow in the horizontal plane at the shoulder level. To evaluate joint viscoelasticity during the learning of this movement, we proposed an index of muscle co-contraction around the joint (IMCJ). The IMCJ was defined as the summation of the absolute values of antagonistic muscle torques around the joint and computed from the linear relation between surface EMG and joint torque. The IMCJ during isometric contraction, as well as during movements, was confirmed to correlate well with joint stiffness estimated using the conventional method, i.e., applying mechanical perturbations. Accordingly, the IMCJ during the learning of the movement was computed for each joint of each trial using estimated EMG-torque relationship. At the same time, the performance error for each trial was specified as the root mean square of the distance between the target and hand at each time step over the entire trajectory. The time-series data of IMCJ and performance error were decomposed into long-term components that

  4. Connectomic and Surface-Based Morphometric Correlates of Acute Mild Traumatic Brain Injury

    PubMed Central

    Dall'Acqua, Patrizia; Johannes, Sönke; Mica, Ladislav; Simmen, Hans-Peter; Glaab, Richard; Fandino, Javier; Schwendinger, Markus; Meier, Christoph; Ulbrich, Erika J.; Müller, Andreas; Jäncke, Lutz; Hänggi, Jürgen

    2016-01-01

    Reduced integrity of white matter (WM) pathways and subtle anomalies in gray matter (GM) morphology have been hypothesized as mechanisms in mild traumatic brain injury (mTBI). However, findings on structural brain changes in early stages after mTBI are inconsistent and findings related to early symptoms severity are rare. Fifty-one patients were assessed with multimodal neuroimaging and clinical methods exclusively within 7 days following mTBI and compared to 53 controls. Whole-brain connectivity based on diffusion tensor imaging was subjected to network-based statistics, whereas cortical surface area, thickness, and volume based on T1-weighted MRI scans were investigated using surface-based morphometric analysis. Reduced connectivity strength within a subnetwork of 59 edges located predominantly in bilateral frontal lobes was significantly associated with higher levels of self-reported symptoms. In addition, cortical surface area decreases were associated with stronger complaints in five clusters located in bilateral frontal and postcentral cortices, and in the right inferior temporal region. Alterations in WM and GM were localized in similar brain regions and moderately-to-strongly related to each other. Furthermore, the reduction of cortical surface area in the frontal regions was correlated with poorer attentive-executive performance in the mTBI group. Finally, group differences were detected in both the WM and GM, especially when focusing on a subgroup of patients with greater complaints, indicating the importance of classifying mTBI patients according to severity of symptoms. This study provides evidence that mTBI affects not only the integrity of WM networks by means of axonal damage but also the morphology of the cortex during the initial post-injury period. These anomalies might be greater in the acute period than previously believed and the involvement of frontal brain regions was consistently pronounced in both findings. The dysconnected subnetwork

  5. Are Movement Disorders and Sensorimotor Injuries Pathologic Synergies? When Normal Multi-Joint Movement Synergies Become Pathologic

    PubMed Central

    Santello, Marco; Lang, Catherine E.

    2015-01-01

    The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system’s ability to control movement. PMID:25610391

  6. Adult hand injuries on artificial ski slopes.

    PubMed

    Keramidas, Evangelos; Miller, Gavin

    2005-10-01

    Artificial ski slope skiing is a popular sport in Great Britain with significant risk of injury. We reviewed 36 patients who had been treated for hand injuries excluding the wrist in our plastic surgery department over a 14-month period after skiing on an artificial ski slope. Specifically, they were 15 fractures of the digits, 3 dislocations of the finger joints, 7 ulnar collateral ligament injuries of the metacarpophalangeal joint of the thumb, and 11 bruises and abrasions. The mean age of the patients was 28 years, and there were 20 men and 16 women. It is concluded that the hardness of the surface of the artificial ski slopes could be responsible for the types of injuries.

  7. A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity.

    PubMed

    Shimamoto, Akira; Yamashita, Keitaro; Inoue, Hirofumi; Yang, Sung-Mo; Iwata, Masahiro; Ike, Natsuko

    2013-04-01

    Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α. The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: RQuota, which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.

  8. Mutual influence of Tweens and dodecyl pyridinium chloride upon their joint adsorption on a surface of paraffin

    NASA Astrophysics Data System (ADS)

    Streltsova, E. A.; Mazuryk, A. A.

    2015-05-01

    The mutual influence of Tweens (Tween-20, Tween-40, Tween-60, Tween-80) and dodecyl pyridinium chloride (DDPC) upon their joint adsorption on the paraffin surface is studied using different molar ratios of components in a bulk aqueous solution. It is shown that both synergistic and antagonistic effects are observed upon the adsorption of cationic and nonionic surfactants from the mixed solutions. The compositions of mixed adsorption layers and the parameters of intermolecular interaction between surfactants of different natures are calculated. A possible mechanism is proposed for the adsorption process.

  9. One Hundred Ninety-five Cases of High-voltage Electric Injury

    DTIC Science & Technology

    2005-08-01

    tissue injury (laceration, contusion, hematoma ): 14 Lung injury (pneumothorax, contusion): 9 Brain/head injury ( subdural hematoma , intraparenchymal...corneal foreign body): 6 Nonfracture orthopedic injury (sprain, open joint): 3 Renal injury ( hematoma , contusion): 2 Intra-abdominal injury (spleen

  10. The quality of bone surfaces may govern the use of model based fluoroscopy in the determination of joint laxity.

    PubMed

    Moewis, P; Wolterbeek, N; Diederichs, G; Valstar, E; Heller, M O; Taylor, W R

    2012-12-01

    The assessment of knee joint laxity is clinically important but its quantification remains elusive. Calibrated, low dosage fluoroscopy, combined with registered surfaces and controlled external loading may offer possible solutions for quantifying relative tibio-femoral motion without soft tissue artefact, even in native joints. The aim of this study was to determine the accuracy of registration using CT and MRI derived 3D bone models, as well as metallic implants, to 2D single-plane fluoroscopic datasets, to assess their suitability for examining knee joint laxity. Four cadaveric knees and one knee implant were positioned using a micromanipulator. After fluoroscopy, the accuracy of registering each surface to the 2D fluoroscopic images was determined by comparison against known translations from the micromanipulator measurements. Dynamic measurements were also performed to assess the relative tibio-femoral error. For CT and MRI derived 3D femur and tibia models during static testing, the in-plane error was 0.4 mm and 0.9 mm, and out-of-plane error 2.6 mm and 9.3 mm respectively. For metallic implants, the in-plane error was 0.2 mm and out-of-plane error 1.5 mm. The relative tibio-femoral error during dynamic measurements was 0.9 mm, 1.2 mm and 0.7 mm in-plane, and 3.9 mm, 10.4 mm and 2.5 mm out-of-plane for CT and MRI based models and metallic implants respectively. The rotational errors ranged from 0.5° to 1.9° for CT, 0.5-4.3° for MRI and 0.1-0.8° for metallic implants. The results of this study indicate that single-plane fluoroscopic analysis can provide accurate information in the investigation of knee joint laxity, but should be limited to static or quasi-static evaluations when assessing native bones, where possible. With this knowledge of registration accuracy, targeted approaches for the determination of tibio-femoral laxity could now determine objective in vivo measures for the identification of ligament reconstruction candidates as well as improve our

  11. A review of metallic, ceramic and surface-treated metals used for bearing surfaces in human joint replacements.

    PubMed

    Dearnley, P A

    1999-01-01

    A review of established and advanced materials used for the bearing surfaces of total hip replacements (THRs), their standards, methods of manufacture and corrosion testing is presented. Some account is also taken of parallel developments in femoral components used in total knee replacements (TKRs). Metallic, ceramic and surface-modified metallic materials are separately reviewed, but wherever possible common practices are collated. Coated implant bearing surfaces are in an advanced state of development and some designs are receiving clinical evaluation. To date, however, no standard methods of manufacturing and testing these materials have been agreed. Accordingly, corrosion and other key quality test methods suitable for surface-modified implant bearing materials are reviewed.

  12. The effects of powered ankle-foot orthoses on joint kinematics and muscle activation during walking in individuals with incomplete spinal cord injury

    PubMed Central

    Sawicki, Gregory S; Domingo, Antoinette; Ferris, Daniel P

    2006-01-01

    Background Powered lower limb orthoses could reduce therapist labor during gait rehabilitation after neurological injury. However, it is not clear how patients respond to powered assistance during stepping. Patients might allow the orthoses to drive the movement pattern and reduce their muscle activation. The goal of this study was to test the effects of robotic assistance in subjects with incomplete spinal cord injury using pneumatically powered ankle-foot orthoses. Methods Five individuals with chronic incomplete spinal cord injury (ASIA C-D) participated in the study. Each subject was fitted with bilateral ankle-foot orthoses equipped with artificial pneumatic muscles to power ankle plantar flexion. Subjects walked on a treadmill with partial bodyweight support at four speeds (0.36, 0.54, 0.72 and 0.89 m/s) under three conditions: without wearing orthoses, wearing orthoses unpowered (passively), and wearing orthoses activated under pushbutton control by a physical therapist. Subjects also attempted a fourth condition wearing orthoses activated under pushbutton control by them. We measured joint angles, electromyography, and orthoses torque assistance. Results A therapist quickly learned to activate the artificial pneumatic muscles using the pushbuttons with the appropriate amplitude and timing. The powered orthoses provided ~50% of peak ankle torque. Ankle angle at stance push-off increased when subjects walked with powered orthoses versus when they walked with passive-orthoses (ANOVA, p < 0.05). Ankle muscle activation amplitudes were similar for powered and passive-orthoses conditions except for the soleus (~13% lower for powered condition; p < 0.05). Two of the five subjects were able to control the orthoses themselves using the pushbuttons. The other three subjects found it too difficult to coordinate pushbutton timing. Orthoses assistance and maximum ankle angle at push-off were smaller when the subject controlled the orthoses compared to when the therapist

  13. Wiener filtering of surface EMG with a priori SNR estimation toward myoelectric control for neurological injury patients.

    PubMed

    Liu, Jie; Ying, Dongwen; Zhou, Ping

    2014-12-01

    Voluntary surface electromyogram (EMG) signals from neurological injury patients are often corrupted by involuntary background interference or spikes, imposing difficulties for myoelectric control. We present a novel framework to suppress involuntary background spikes during voluntary surface EMG recordings. The framework applies a Wiener filter to restore voluntary surface EMG signals based on tracking a priori signal to noise ratio (SNR) by using the decision-directed method. Semi-synthetic surface EMG signals contaminated by different levels of involuntary background spikes were constructed from a database of surface EMG recordings in a group of spinal cord injury subjects. After the processing, the onset detection of voluntary muscle activity was significantly improved against involuntary background spikes. The magnitude of voluntary surface EMG signals can also be reliably estimated for myoelectric control purpose. Compared with the previous sample entropy analysis for suppressing involuntary background spikes, the proposed framework is characterized by quick and simple implementation, making it more suitable for application in a myoelectric control system toward neurological injury rehabilitation.

  14. An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

    SciTech Connect

    Vianco, P.T.

    1998-10-15

    A overview has been presented on the topic of alternative surface finishes for package I/Os and circuit board features. Aspects of processability and solder joint reliability were described for the following coatings: baseline hot-dipped, plated, and plated-and-fused 100Sn and Sn-Pb coatings; Ni/Au; Pd, Ni/Pd, and Ni/Pd/Au finishes; and the recently marketed immersion Ag coatings. The Ni/Au coatings appear to provide the all-around best option in terms of solderability protection and wire bondability. Nickel/Pal ftishes offer a slightly reduced level of performance in these areas that is most likely due to variable Pd surface conditions. It is necessmy to minimize dissolved Au or Pd contents in the solder material to prevent solder joint embrittlement. Ancillary aspects that included thickness measurement techniques; the importance of finish compatibility with conformal coatings and conductive adhesives; and the need for alternative finishes for the processing of non-Pb bearing solders were discussed.

  15. Corrosion Behavior of Top and Bottom Surfaces for Single-Side and Double-Side Friction Stir Welded 7085-T7651 Aluminum Alloy Thick Plate Joints

    NASA Astrophysics Data System (ADS)

    Xu, Weifeng; Zhang, Wei; Wu, Xiaoli

    2017-01-01

    Thick plate joints of 7085-T7451 aluminum alloy were obtained through both single-side and double-side friction stir welding (SS or DS-FSW). The chloride ions effects on the corrosion behavior of the top and bottom surfaces of the joints were examined by cyclic potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Results show that the corrosion susceptibility was suppressed significantly in the weld nugget zone, while the base material and heat-affected zone were prone to be corrosion attacked. For the SS-FSWed joint, the top surface showed a higher corrosion resistance than that of the bottom surface, but the larger corrosive heterogeneity was observed between the top and bottom surfaces compared with the two welds of DS-FSWed joint, which was confirmed by the morphology of corrosion attack. A deep insight on the microstructure of the joints indicates that the intermetallic particles played a key role in the corrosion behavior of the FSWed AA7085 aluminum alloy joints in chloride solution.

  16. Corrosion Behavior of Top and Bottom Surfaces for Single-Side and Double-Side Friction Stir Welded 7085-T7651 Aluminum Alloy Thick Plate Joints

    NASA Astrophysics Data System (ADS)

    Xu, Weifeng; Zhang, Wei; Wu, Xiaoli

    2017-03-01

    Thick plate joints of 7085-T7451 aluminum alloy were obtained through both single-side and double-side friction stir welding (SS or DS-FSW). The chloride ions effects on the corrosion behavior of the top and bottom surfaces of the joints were examined by cyclic potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Results show that the corrosion susceptibility was suppressed significantly in the weld nugget zone, while the base material and heat-affected zone were prone to be corrosion attacked. For the SS-FSWed joint, the top surface showed a higher corrosion resistance than that of the bottom surface, but the larger corrosive heterogeneity was observed between the top and bottom surfaces compared with the two welds of DS-FSWed joint, which was confirmed by the morphology of corrosion attack. A deep insight on the microstructure of the joints indicates that the intermetallic particles played a key role in the corrosion behavior of the FSWed AA7085 aluminum alloy joints in chloride solution.

  17. Acromioclavicular Joint Separations

    DTIC Science & Technology

    2013-01-01

    non-surgical measures, high-grade inju- ries frequently warrant surgical intervention to minimize pain and maximize shoulder function. Factors such as...sports [1–3]. While most injuries can be managed non-operatively, high-grade separations may result in per- sistent pain or functional decline and...joint pathology (cross arm adduction and loading of the AC joint) can be helpful to localize shoulder pain to the AC joint. These tests are especial- ly

  18. Sacroiliac injuries in horses.

    PubMed

    Lorenz, Jennifer; Brounts, Sabrina H

    2012-11-01

    This article reviews the pathology, diagnosis, and treatment of sacroiliac joint injuries. These injuries can be acute or chronic and can involve soft tissue structures surrounding the joint or the bony structures of the joint. The several diagnostic modalities for sacroiliac injuries vary in usefulness and accessibility. Treatment of sacroiliac problems is usually supportive and nonspecific and includes the use of antiinflammatory medications and an appropriate exercise regimen. The prognosis depends on the cause, but severe injuries can limit a horse's future athletic activity.

  19. Electrical properties of rat muscle after sciatic nerve injury: Impact on surface impedance measurements assessed via finite element analysis

    NASA Astrophysics Data System (ADS)

    Ahad, M. A.; Rutkove, S. B.

    2010-04-01

    Tetrapolar surface electrical impedance methods are sensitive to changes in muscle status and can therefore provide a means for studying neuromuscular disease noninvasively. In order to better understand the relationship between surface impedance measurements and the actual muscle electrical properties, we performed measurements on 20 adult Wistar rats, 8 of which underwent sciatic nerve crush. Surface impedance measurements were performed on the left hind limb both before injury and out to 2 weeks after injury. In addition, both normal and sciatic crush animals were sacrificed and the dielectric properties of the extracted gastrocnemius muscle measured. We found that 50 kHz conductivities were greater in the animals that underwent crush than in the animals that did not. The permittivities in both directions, however, showed non-significant differences. In order to analyze the effect of these changes as well as the accompanying reduction in muscle volume, a finite element model of the hind limb was developed based on computerized tomographic imaging. The model successfully predicted the surface impedance values in the animals after crush injury and, by its inverse application, may be used to help determine the underlying electrical properties of muscle in various neuromuscular diseases based on surface impedance data.

  20. Surface modifications of nylon/carbon fiber composite for improving joint adhesion

    SciTech Connect

    Wu, R.; Liao, S.L.; Tong, T.S.; Young, J.T.

    1996-12-31

    Various methods were used to modify the nylon/carbon fiber composite surfaces, including grit blasting, flame and plasma pretreatments. The surfaces of nylon composites after pretreatments were characterized by contact angle measurements, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). XPS results show that several functional groups were formed after plasma and flame pretreatments. The scanning electron microscope (SEM) photographs suggest that the blasting pretreatment increased the surface roughness of nylon composites. All these surface pretreatments dramatically increased the lap shear strength if proper operation conditions were used. The reasons for the increase of lap shear strength were explained.

  1. Quantitative investigation of surface and subsurface fatigue cracks near rivets in riveted joints using acoustic, electron and optical microscopy

    NASA Astrophysics Data System (ADS)

    Connor, Zayna Marie

    2000-10-01

    Using scanning acoustic microscopy, optical microscopy and scanning electron microscopy, in conjunction with fractography of fractured surfaces, the crack formation and growth kinetics of subsurface fatigue cracks and surface breaking fatigue cracks near rivets have been characterized in detail in this research. The scanning acoustic microscope was used to quantitatively investigate subsurface fatigue cracks (even when they were very small) at and near countersunk rivets in riveted lap joint specimens that are similar to the riveted lap joints found in the fuselages of many aircraft. It was found that the maximum nominal applied stress influences the fatigue crack initiation and propagation behavior. Eyebrow type cracks develop at lower stresses and centerline cracks develop at higher stresses. At low stress ranges, the fatigue cracks initiate a short distance from the rivet at or near the hidden surface of the chamfered panel. At higher stress amplitudes, the cracks initiate at the blunt knife edge. Residual compressive stresses and fretting are suggested to play more important roles at lower stress ranges. Both types of cracks initiate in a shear mode but transform to tensile, mode I, cracks as they grow. This transition occurs much more rapidly at the higher stress amplitude. At both high and low stresses, the cracks are longer on the fayed surface of the panel than elsewhere. In a comparison of Alclad 2024-T3 and Alclad 2524-T3, it was found that the high purity aluminum alloy 2524 nucleates cracks at a greater number of cycles than the less pure aluminum alloy 2024. At high stress, crack initiation plays less of a roll and the 2024 alloy has a longer life. The scanning acoustic microscope enabled us to study subsurface fatigue cracks. The understanding gained from the characterization of the subsurface fatigue cracks will help in the modeling of crack initiation and growth in the riveted lap joint and will also aid in the improvement of NDE techniques for the

  2. Fast pitch softball injuries.

    PubMed

    Meyers, M C; Brown, B R; Bloom, J A

    2001-01-01

    The popularity of fast pitch softball in the US and throughout the world is well documented. Along with this popularity, there has been a concomitant increase in the number of injuries. Nearly 52% of cases qualify as major disabling injuries requiring 3 weeks or more of treatment and 2% require surgery. Interestingly, 75% of injuries occur during away games and approximately 31% of traumas occur during nonpositional and conditioning drills. Injuries range from contusions and tendinitis to ligamentous disorders and fractures. Although head and neck traumas account for 4 to 12% of cases, upper extremity traumas account for 23 to 47% of all injuries and up to 19% of cases involve the knee. Approximately 34 to 42% of injuries occur when the athlete collides with another individual or object. Other factors involved include the quality of playing surface, athlete's age and experience level, and the excessive physical demands associated with the sport. Nearly 24% of injuries involve base running and are due to poor judgement, sliding technique, current stationary base design, unorthodox joint and extremity position during ground impact and catching of cleats. The increasing prevalence of overtraining syndrome among athletes has been attributed to an unclear definition of an optimal training zone, poor communication between player and coach, and the limited ability of bone and connective tissue to quickly respond to match the demands of the sport. This has led routinely to arm, shoulder and lumbar instability, chronic nonsteroidal anti-inflammatory drug (NSAID) use and time loss injuries in 45% of pitching staff during a single season. Specific attention to a safer playing environment, coaching and player education, and sport-specific training and conditioning would reduce the risk, rate and severity of fast pitch traumas. Padding of walls, backstops, rails and dugout areas, as well as minimising use of indoor facilities, is suggested to decrease the number of collision

  3. Synovial tissue morphology of the cricoarytenoid joint in the elderly: a histological comparison with the cricothyroid joint

    PubMed Central

    Katsumura, Sakura; Kitamura, Kei; Kasahara, Masaaki; Katori, Yukio; Abe, Shin-ichi

    2016-01-01

    We compared the age-related morphology of the cricothyroid (CT) joint with that of the cricoarytenoid (CA) joint using 18 specimens from elderly cadavers in terms of their elastic fiber contents as well as the cells composing the joint capsule and synovial tissues. In contrast to an almost flat-flat interface in the CT joint, the CA joint was similar to a saddle joint. The CA joint capsule was thin and contained few elastic fibers, and in contrast to the CT joint, external fibrous tissues were not exposed to the joint cavity, there being no injury to the CA joint capsule. The lateral and posterior aspects of the CA joint were covered by the lateral and posterior CA muscles, respectively, and the fascia of the latter muscle was sometimes thick with abundant elastic fibers. However, due to possible muscle degeneration, loose connective tissue was often interposed between the fascia and the capsule. The medial and anterior aspects of the CA joint faced loose tissue that was continuous with the laryngeal submucosal tissue. Therefore, in contrast to the CT joint, a definite supporting ligament was usually absent in the CA joint. Synovial folds were always seen in the CA joint, comprising a short triangular mass on the posterior side and long laminar folds on the anterior side. The synovial folds usually contained multiple capillaries and a few CD68-positive macrophages. High congruity of the CA joint surfaces as well as strong muscle support to the arytenoid cartilage appeared to provide the specific synovial morphology. PMID:27051568

  4. Physical property-, lithology- and surface geometry-based joint inversion using Pareto multi-objective global optimization

    NASA Astrophysics Data System (ADS)

    Bijani, Rodrigo; Lelièvre, Peter G.; Ponte-Neto, Cosme F.; Farquharson, Colin G.

    2017-02-01

    This paper is concerned with the applicability of Pareto Multi-Objective Global Optimization (PMOGO) algorithms for solving different types of geophysical inverse problems. The standard deterministic approach is to combine the multiple objective functions (i.e. data misfit, regularization and joint coupling terms) in a weighted-sum aggregate objective function and minimize using local (decent-based) smooth optimization methods. This approach has some disadvantages: 1) appropriate weights must be determined for the aggregate, 2) the objective functions must be differentiable, and 3) local minima entrapment may occur. PMOGO algorithms can overcome these drawbacks but introduce increased computational effort. Previous work has demonstrated how PMOGO algorithms can overcome the first issue for single data set geophysical inversion, i.e. the tradeoff between data misfit and model regularization. However, joint inversion, which can involve many weights in the aggregate, has seen little study. The advantage of PMOGO algorithms for the other two issues has yet to be addressed in the context of geophysical inversion. In this paper, we implement a PMOGO genetic algorithm and apply it to physical property-, lithology- and surface geometry-based inverse problems to demonstrate the advantages of using a global optimization strategy. Lithological inversions work on a mesh but use integer model parameters representing rock unit identifiers instead of continuous physical properties. Surface geometry inversions change the geometry of wireframe surfaces that represent the contacts between discrete rock units. Despite the potentially high computational requirements of global optimization algorithms (compared to local), their application to realistically-sized 2D geophysical inverse problems is within reach of current capacity of standard computers. Furthermore, they open the door to geophysical inverse problems that could not otherwise be considered through traditional optimization

  5. Crustal layering in northeastern Tibet: a case study based on joint inversion of receiver functions and surface wave dispersion

    NASA Astrophysics Data System (ADS)

    Deng, Yangfan; Shen, Weisen; Xu, Tao; Ritzwoller, Michael H.

    2015-10-01

    Recently constructed models of crustal structure across Tibet based on surface wave data display a prominent mid-crustal low velocity zone (LVZ) but are vertically smooth in the crust. Using six months of broad-band seismic data recorded at 22 stations arrayed approximately linearly over a 440 km observation profile across northeastern Tibet (from the Songpan-Ganzi block, through the Qaidam block, into the Qilian block), we perform a Bayesian Monte Carlo joint inversion of receiver function data with surface wave dispersion to address whether crustal layering is needed to fit both data sets simultaneously. On some intervals a vertically smooth crust is consistent with both data sets, but across most of the observation profile two types of layering are required: a discrete LVZ or high velocity zone (HVZ) formed by two discontinuities in the middle crust and a doublet Moho formed by two discontinuities from 45-50 km to 60-65 km depth connected by a linear velocity gradient in the lowermost crust. The final model possesses (1) a mid-crustal LVZ that extends from the Songpan-Ganzi block through the Kunlun suture into the Qaidam block consistent with partial melt and ductile flow and (2) a mid-crustal HVZ bracketing the south Qilian suture coincident with ultrahigh pressure metamorphic rocks at the surface. (3) Additionally, the model possesses a doublet Moho extending from the Qaidam to the Qilian blocks which probably reflects increased mafic content with depth in the lowermost crust perhaps caused by a vertical gradient of ecologitization. (4) Crustal thickness is consistent with a step-Moho that jumps discontinuously by 6 km from 63.8 km (±1.8 km) south of 35° to 57.8 km (±1.4 km) north of this point coincident with the northern terminus of the mid-crustal LVZ. These results are presented as a guide to future joint inversions across a much larger region of Tibet.

  6. Effect of Toll-Like Receptor 4 on Synovial Injury of Temporomandibular Joint in Rats Caused by Occlusal Interference

    PubMed Central

    Kong, Jingjing; Yang, Yingying; Sun, Shuzhen; Xie, Jianli; Lin, Xuefen; Ji, Ping

    2016-01-01

    Synovitis is an important disease that causes intractable pain in TMJ. Some investigations suggested that the increasing expression of IL-1β secreted by synovial lining cells plays an important role in synovial inflammation and cartilage destruction in TMJ. In our previous research, the results demonstrated that TLR4 is involved in the expression of IL-1β in SFs from TMJ with lipopolysaccharide stimulation. However, the inflammatory response that occurred in synovial membrane is not caused by bacterial infection. In the current study, we investigated whether or not TLR4 participates in the inflammatory responses and the expression of IL-1β in synovial membrane of rats induced by occlusal interference. The results showed that obvious inflammation changes were observed in the synovial membranes and the expression of TLR4 and IL-1β was increased at both mRNA and protein levels in the occlusal interference rats. In addition, the inflammation reactions and the increased expression of IL-1β could be restrained by treatment with TAK-242, a blocker of TLR4 signaling. The results prompted us that the activation of TLR4 may be involved in the inflammatory reactions and increased expression of IL-1β in patients with synovitis and participate in the mechanisms of the initiation and development of synovial injury by regulating the expression of inflammatory mediators like IL-1β in synovial membranes. PMID:27413256

  7. Thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth versus agar surface.

    PubMed

    Wang, Xiang; Devlieghere, Frank; Geeraerd, Annemie; Uyttendaele, Mieke

    2017-02-21

    The objective of the present study was to compare the thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth (suspended cells) and on solid surface (agar-seeded cells). A 3-strain cocktail of S. enterica or L. monocytogenes inoculated in broth or on agar was subjected to heating in a water bath at various set temperatures (55.0, 57.5 and 60.0°C for S. enterica and 60.0, 62.5 and 65°C for L. monocytogenes). The occurrence of sublethally injured cells was determined by comparing enumerations on nonselective (TSAYE) and selective (XLD or ALOA) media. Results showed that the inactivation curves obtained from selective media were log-linear, and significant shoulders (p<0.05) were observed on some of the inactivation curves from TSAYE media. The D-values derived from the total population were higher than those from the uninjured cells. Generally, cells on agar surface exhibited higher heat resistance than those in broth. For S. enterica, cell injury increased with the exposure time, no difference was observed when treated at temperatures from 55.0 to 60.0°C, while for L. monocytogenes, cell injury increased significantly with heating time and treatment temperature (from 60.0 to 65°C). Moreover, the degree of sublethal injury affected by thermal treatment in broth or on agar surface depended upon the target microorganism. Higher proportions of injured S. enterica cells were observed for treatment in broth than on agar surface, while the opposite was found for L. monocytogenes. The provided information may be used to assess the efficacy of thermal treatment processes on surfaces for inactivation of S. enterica and L. monocytogenes, and it provides insight into the sublethally injured survival state of S. enterica and L. monocytogenes treated in liquid or on solid food.

  8. Continental like crust beneath the Andaman Island through joint inversion of receiver function and surface wave from ambient seismic noise

    NASA Astrophysics Data System (ADS)

    Gupta, Sandeep; Borah, Kajaljyoti; Saha, Gokul

    2016-09-01

    We study shear wave velocity structure of the crust beneath the Andaman Island through joint inversion of the teleseismic receiver function and Rayleigh wave group velocity measurements from 10 broadband seismographs over the Island. The group velocities in the periods from 5 to 21 s are obtained using cross-correlation of six month's ambient seismic noise data recorded by these seismic stations. Joint inversion results show 2 to 6 km thick subsurface low shear velocity (Vs 1.3-2.5 km/s) layer followed by a 12-14 km thick layer of silicic material (average Vs 3.5 km/s). The lower crust is mapped as an 8-12 km thick mafic layer with Vs 4.0 km/s. Uppermost mantle shear wave velocity is 4.55 km/s. The near-surface low-velocity layer is interpreted as the Andaman flysch sediments. The crustal thickness beneath the Andaman Island varies from 24 km in the north to 32 km in the south. The shear wave velocity-depth results show that the crustal structure beneath the Andaman Island is akin to continental crust, possibly the Burma continental crust. The subducting Indian plate may lie down below this overriding plate.

  9. Contact areas of the tibiotalar joint.

    PubMed

    Windisch, Gunther; Odehnal, Boris; Reimann, Reinhold; Anderhuber, Friedrich; Stachel, Hellmuth

    2007-11-01

    The contact areas between the articular surfaces of the talus and tibia are essential for understanding the mobility of the ankle joint. The purpose of our study was to reveal the contact area among the superior articular surface of the trochlea tali (target surface T) and the inferior articular surface of the tibia (query surface Q) under non-weight-bearing conditions in plantar flexion and dorsiflexion. Twenty cadaveric foot specimens were dissected and scanned by a three-dimensional (3D) laser scanner to obtain data point sets. These point sets were triangulated and a registration procedure performed to avoid any intersection of the two joint surfaces. For all points of the query surface Q, the closest distance to T was measured. In 11 of the 20 ankle joints, the contact area was larger in plantar flexion, in 5 it was nearly of equal size, and in 4 the two surfaces were found in a better congruence in dorsiflexion. The two articular surfaces can be in point or line contact and cause different motions while T is gliding on Q, so the original geometry of ligaments must be carefully reconstructed after injury or during total ankle replacement.

  10. Overuse Injury: How to Prevent Training Injuries

    MedlinePlus

    ... type of muscle or joint injury, such as tendinitis or a stress fracture, that's caused by repetitive ... Khan K, et al. Overview of chronic (overuse) tendinopathies. http://www.uptodate.com/home. Accessed Dec. 21, ...

  11. Joint Sensing/Sampling Optimization for Surface Drifting Mine Detection with High-Resolution Drift Model

    DTIC Science & Technology

    2012-09-01

    estimation of surrounding environmental effects and therefore provide time critical estimations of target movement. These approximations can be used to...model could offer an estimation of surrounding environmental effects and therefore provide time critical estimations of target movement. These...Explosive Ordnance Disposal MCM Mine Countermeasures MEDAL Mine Warfare Environmental Decisions Aid Library MMS Marine Mammal Systems SMCM Surface

  12. Alteration of cartilage surface collagen fibers differs locally after immobilization of knee joints in rats.

    PubMed

    Nagai, Momoko; Aoyama, Tomoki; Ito, Akira; Tajino, Junichi; Iijima, Hirotaka; Yamaguchi, Shoki; Zhang, Xiangkai; Kuroki, Hiroshi

    2015-05-01

    The purpose of this study was to examine the ultrastructural changes of surface cartilage collagen fibers, which differ by region and the length of the experimental period in an immobilization model of rat. Male Wistar rats were randomly divided into histological or macroscopic and ultrastructural assessment groups. The left knees of all the animals were surgically immobilized by external fixation for 1, 2, 4, 8 or 16 weeks (n = 5/time point). Sagittal histological sections of the medial mid-condylar region of the knee were obtained and assessed in four specific regions (contact and peripheral regions of the femur and tibia) and two zones (superficial and deep). To semi-quantify the staining intensity of the collagen fibers in the cartilage, picrosirius red staining was used. The cartilage surface changes of all the assessed regions were investigated by scanning electron microscopy (SEM). From histological and SEM observations, the fibrillation and irregular changes of the cartilage surface were more severe in the peripheral region than in the contact region. Interestingly, at 16 weeks post-immobilization, we observed non-fibrous structures at both the contact and peripheral regions. The collagen fiber staining intensity decreased in the contact region compared with the peripheral region. In conclusion, the alteration of surface collagen fiber ultrastructure and collagen staining intensity differed by the specific cartilage regions after immobilization. These results demonstrate that the progressive degeneration of cartilage is region specific, and depends on the length of the immobilization period.

  13. Joint Prediction of Longitudinal Development of Cortical Surfaces and White Matter Fibers from Neonatal MRI.

    PubMed

    Rekik, Islem; Li, Gang; Yap, Pew-Thian; Chen, Geng; Lin, Weili; Shen, Dinggang

    2017-03-08

    The human brain can be modeled as multiple interrelated shapes (or a multishape), each for characterizing one aspect of the brain, such as the cortex and white matter pathways. Predicting the developing multishape is a very challenging task due to the contrasting nature of the developmental trajectories of the constituent shapes: smooth for the cortical surface and non-smooth for white matter tracts due to changes such as bifurcation. We recently addressed this problem and proposed an approach for predicting the multishape developmental spatiotemporal trajectories of infant brains based only on neonatal MRI data using a set of geometric, dynamic, and fiber-to-surface connectivity features. In this paper, we propose two key innovations to further improve the prediction of multishape evolution. First, for a more accurate cortical surface prediction, instead of simply relying on one neonatal atlas to guide the prediction of the multishape, we propose to use multiple neonatal atlases to build a spatially heterogeneous atlas using the multidirectional varifold representation. This individualizes the atlas by locally maximizing its similarity to the testing baseline cortical shape for each cortical region, thereby better representing the baseline testing cortical surface, which founds the multishape prediction process. Second, for temporally consistent fiber prediction, we propose to reliably estimate spatiotemporal connectivity features using low-rank tensor completion, thereby capturing the variability and richness of the temporal development of fibers. Experimental results confirm that the proposed variants significantly improve the prediction performance of our original multishape prediction framework for both cortical surfaces and fiber tracts shape at 3, 6, and 9 months of age. Our pioneering model will pave the way for learning how to predict the evolution of anatomical shapes with abnormal changes. Ultimately, devising accurate shape evolution prediction models

  14. Precision holding prediction model for moving joint surfaces of large machine tool

    NASA Astrophysics Data System (ADS)

    Wang, Mulan; Chen, Xuanyu; Ding, Wenzheng; Xu, Kaiyun

    2017-01-01

    In large machine tool, the plastic guide rail is more and more widely used because of its good mechanical properties. Based on the actual operating conditions of the machine tool, this paper analyzes the precision holding performance of the main bearing surface of the large machine tool with plastic guide rail moving. The precision holding performance of the plastic sliding guide rail is studied in detail from several aspects, such as the lubrication condition, the operating parameters of the machine tool and the material properties. The precision holding model of the moving binding surface of the plastic coated guide rail is established. At the same time, the experimental research on the accuracy of the guide rail is carried out, which verifies the validity of the theoretical model.

  15. A sequential data assimilation approach for the joint reconstruction of mantle convection and surface tectonics

    NASA Astrophysics Data System (ADS)

    Bocher, M.; Coltice, N.; Fournier, A.; Tackley, P. J.

    2016-01-01

    With the progress of mantle convection modelling over the last decade, it now becomes possible to solve for the dynamics of the interior flow and the surface tectonics to first order. We show here that tectonic data (like surface kinematics and seafloor age distribution) and mantle convection models with plate-like behaviour can in principle be combined to reconstruct mantle convection. We present a sequential data assimilation method, based on suboptimal schemes derived from the Kalman filter, where surface velocities and seafloor age maps are not used as boundary conditions for the flow, but as data to assimilate. Two stages (a forecast followed by an analysis) are repeated sequentially to take into account data observed at different times. Whenever observations are available, an analysis infers the most probable state of the mantle at this time, considering a prior guess (supplied by the forecast) and the new observations at hand, using the classical best linear unbiased estimate. Between two observation times, the evolution of the mantle is governed by the forward model of mantle convection. This method is applied to synthetic 2-D spherical annulus mantle cases to evaluate its efficiency. We compare the reference evolutions to the estimations obtained by data assimilation. Two parameters control the behaviour of the scheme: the time between two analyses, and the amplitude of noise in the synthetic observations. Our technique proves to be efficient in retrieving temperature field evolutions provided the time between two analyses is ≲10 Myr. If the amplitude of the a priori error on the observations is large (30 per cent), our method provides a better estimate of surface tectonics than the observations, taking advantage of the information within the physics of convection.

  16. Effects of Microstructure and Loading on Fracture of Sn-3.8Ag-0.7Cu Joints on Cu Substrates with ENIG Surface Finish

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Kumar, P.; Dutta, I.; Sidhu, R.; Renavikar, M.; Mahajan, R.

    2014-12-01

    When dropped, electronic packages often undergo failure by propagation of an interfacial crack in solder joints under a combination of tensile and shear loading. Hence, it is crucial to understand and predict the fracture behavior of solder joints under mixed-mode high-rate loading conditions. In this work, the effects of the loading conditions (strain rate and loading angle) and microstructure [interfacial intermetallic compound (IMC) morphology and solder yield strength] on the mixed-mode fracture toughness of Sn-3.8 wt.%Ag-0.7 wt.%Cu solder joints sandwiched between two Cu substrates with electroless nickel immersion gold (ENIG) metallization have been studied, and compared with the fracture behavior of joints attached to bare Cu. Irrespective of the surface finish, the fracture toughness of the solder joints decreased monotonically with strain rate and mode-mixity, both resulting in increased fracture proportion through the interfacial IMC layer. Furthermore, the proportion of crack propagation through the interfacial IMC layer increased with increase in the thickness and the roughness of the interfacial IMC layer and the yield strength of the solder, resulting in a decrease in the fracture toughness of the joint. However, under most conditions, solder joints with ENIG finish showed higher resistance to fracture than joints attached directly to Cu substrates without ENIG metallization. Based on the experimental observations, a fracture mechanism map is constructed correlating the yield strength of the solder, the morphology and thickness of the interfacial IMC, and the fracture mechanisms as well as the fracture toughness values for different solder joints under mode I loading.

  17. Effects of mobility/immobility of surface modification by 2-methacryloyloxyethyl phosphorylcholine polymer on the durability of polyethylene for artificial joints.

    PubMed

    Kyomoto, Masayuki; Moro, Toru; Miyaji, Fumiaki; Hashimoto, Masami; Kawaguchi, Hiroshi; Takatori, Yoshio; Nakamura, Kozo; Ishihara, Kazuhiko

    2009-08-01

    Surface modification is important for the improvement in medical device materials. 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers have attracted considerable attention as surface modifiable polymers for several medical devices. In this study, we hypothesize that the structure of the surface modification layers might affect the long-term stability, hydration kinetics, wear resistance, and so forth, of medical devices such as artificial joints, and the poly(MPC) (PMPC) grafted surface might assure the long-term performance of such devices. Therefore, we investigate the surface properties of various surface modifications by using dip coatings of MPC-co-n-butyl methacrylate (PMB30) and MPC-co-3-methacryloxypropyl trimethoxysilane (PMSi90) polymers, or photoinduced radical grafting of PMPC and also the effects of the surface properties on the durability of cross-linked polyethylene (CLPE) for artificial joints. The PMPC-grafted CLPE has an extremely low and stable coefficient of dynamic friction and volumetric wear as compared to the untreated CLPE, PMB30-coated CLPE, and PMSi90-coated CLPE. It is concluded that the photoinduced radical graft polymerization of MPC is the best method to retain the benefits of the MPC polymer used in artificial joints under variable and multidirectional loads for long periods with strong bonding between the MPC polymer and the CLPE surface, and also to retain the high mobility of the MPC polymer.

  18. Drop Reliability of Epoxy-contained Sn-58 wt.%Bi Solder Joint with ENIG and ENEPIG Surface Finish Under Temperature and Humidity Test

    NASA Astrophysics Data System (ADS)

    Myung, Woo-Ram; Kim, Yongil; Kim, Kyung-Yeol; Jung, Seung-Boo

    2016-07-01

    The influence of two kinds of surface finish, namely electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG), on the interfacial reactions and drop reliability of epoxy-enhanced Sn-58 wt.%Bi solder has been investigated after temperature-humidity storage tests. The chemical composition and morphology of intermetallic compounds (IMCs) were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electron probe microanalysis. Also, the mechanical reliability of solder joints was evaluated using board-level drop tests. The Sn-Bi epoxy solder/ENEPIG joint exhibited higher IMC growth rate than the Sn-Bi epoxy solder/ENIG joint. After 500 h at 85°C/85% RH storage condition, new IMCs were formed on the Ni3Sn4 layer in samples with both surface finishes. The results of board-level drop tests showed that the number of drops was higher for the ENIG than the ENEPIG surface finish. Solder joint fracture occurred along the interface between the solder and IMC layer for the ENIG surface finish. However, with the ENEPIG surface finish, the crack propagated between the IMCs.

  19. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  20. The Sauvé-Kapandji procedure for chronic dislocation of the distal radio-ulnar joint with destruction of the articular surface.

    PubMed

    Nakamura, R; Tsunoda, K; Watanabe, K; Horii, E; Miura, T

    1992-04-01

    The Sauvé-Kapandji procedure has been performed in 15 non-rheumatoid patients with chronic distal radio-ulnar joint dislocation accompanied by joint damage or deformity. The clinical results were favourable; wrist pain improved in all patients, wrist flexion-extension was increased by more than 10 degrees in nine patients, grip strength of at least 80% of the contralateral wrist was achieved in 11 patients, and forearm rotation was more than 150 degrees in 12 patients. However, X-ray examination revealed an unstable proximal ulnar stump and radio-ulnar convergence in all patients similar to that associated with the Darrach procedure. Although the Sauvé-Kapandji procedure can preserve ulnar support of the wrist and is believed to yield more satisfactory results than the Darrach procedure, its extensive use is not recommended for non-rheumatoid distal radio-ulnar joint disorders, but it is recommended for chronic distal radio-ulnar joint dislocation with articular injury or deformity.

  1. The Crust and Upper Mantle Structure of the Iranian Plateau from Joint Waveform Tomography Imaging of Body and Surface Waves

    NASA Astrophysics Data System (ADS)

    Roecker, S. W.; Priestley, K. F.; Tatar, M.

    2014-12-01

    The Iranian Plateau forms a broad zone of deformation between the colliding Arabian and Eurasian plates. The convergence is accommodated in the Zagros Mountains of SW Iran, the Alborz Mountains of northern Iran, and the Kopeh Dagh Mountains of NE Iran. These deforming belts are separated by relatively aseismic depressions such as the Lut Block. It has been suggested that the Arabia-Eurasia collision is similar to the Indo-Eurasia collision but at a early point of development and therefore, it may provide clues to our understanding of the earlier stages of the continent-continent collision process. We present results of the analysis of seismic data collected along two NE-SW trending transects across the Iranian Plateau. The first profile extends from near Bushere on the Persian Gulf coast to near to the Iran-Turkmenistan border north of Mashad, and consists of seismic recordings along the SW portion of the line in 2000-2001 and recording along the NE portion of the line in 2003 and 2006-2008. The second profile extends from near the Iran-Iraq border near the Dezfel embayment to the south Caspian Sea coast north of Tehran. We apply the combined 2.5D finite element waveform tomography algorithm of Baker and Roecker [2014] to jointly invert teleseismic body and surface waves to determine the elastic wavespeed structures of these areas. The joint inversion of these different types of waves affords similar types of advantages that are common to combined surface wave dispersion/receiver function inversions in compensating for intrinsic weaknesses in horizontal and vertical resolution capabilities. We compare results recovered from a finite difference approach to document the effects of various assumptions related to their application, such as the inclusion of topography, on the models recovered. We also apply several different inverse methods, starting with simple gradient techniques to the more sophisticated pseudo-Hessian or L-BFGS approach, and find that the latter are

  2. Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers

    PubMed Central

    López-Jiménez, Lidia; Viñas, Miguel; Vinuesa, Teresa

    2015-01-01

    Aim: To visualize by Atomic Force Microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Material and Methods: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by Atomic Force Microscopy (AFM) and its surface roughness determined. Results: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. Conclusions: AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability. Key words:Atomic force microscopy, Er,Cr:YSGG laser, diode laser, Enterococcus faecalis, surface roughness. PMID:25475770

  3. Joint replacement components made of hot-forged and surface-treated Ti-6Al-7Nb alloy.

    PubMed

    Semlitsch, M F; Weber, H; Streicher, R M; Schön, R

    1992-01-01

    We have developed a titanium-aluminium alloy with the inert alloying element niobium. The optimal composition was found to be Ti-6Al-7Nb (Protasul-100). This custom-made alloy designed for implants shows the same alpha/beta structure as Ti-6Al-4V and exhibits equally good mechanical properties. The corrosion resistance of Ti-6Al-7Nb in sodium chloride solution is equivalent to that of pure titanium and Ti-6Al-4V. This is due to a very dense and stable passive layer. Highly stressed anchorage stems of different hip prosthesis designs have been made from hot-forged Ti-6Al-7Nb. The polished surfaces of hip, knee and wrist joints made of Ti-6Al-7Nb and articulating against polyethylene are surface-treated by means of a very hard and 3-5 microns thick titanium nitride coating (Tribosul-TiN) or by oxygen diffusion hardening (Tribosul-ODH) to a depth of 30 microns.

  4. Heat-resistant organic molecular layer as a joint interface for metal reduction on plastics surfaces

    NASA Astrophysics Data System (ADS)

    Sang, Jing; Aisawa, Sumio; Hirahara, Hidetoshi; Kudo, Takahiro; Mori, Kunio

    2016-04-01

    Heat-resistant organic molecular layers have been fabricated by triazine-based silane coupling agent for metal reduction on plastic surfaces using adsorption method. These molecular layers were used as an interfacial layer between polyamide (PA6) and metal solution to reduce Ag+ ion to Ag0. The interfacial behaviors of triazine molecular layer at the interfaces between PA6 and Ag solution were investigated using quartz crystal microbalance (QCM). The kinetics of molecular adsorption on PA6 was investigated by using triazine-based silane coupling agent solutions at different pH and concentration. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and local nano thermal analysis were employed to characterize the surfaces and interfaces. The nano thermal analysis results show that molecular layers of triazine-based silane coupling agent greatly improved heat resistance of PA6 resin from 170 °C up to 230 °C. This research developed an in-depth insight for molecular behaviors of triazine-based silane coupling agent at the PA6 and Ag solution interfaces and should be of significant value for interfacial research between plastics and metal solution in plating industry.

  5. Joint State and Parameter Estimation for Two Land Surface Models Using the Ensemble Kalman Filter and Particle Filter

    NASA Astrophysics Data System (ADS)

    Zhang, Hongjuan; Hendricks-Franssen, Harrie-Jan; Han, Xujun; Vrugt, Jasper A.; Vereecken, Harry

    2016-04-01

    Land surface models (LSMs) resolve the water and energy balance with different parameters and state variables. Many of the parameters of these models cannot be measured directly in the field, and require calibration against flux and soil moisture data. Two LSMs are used in our work: Variable Infiltration Capacity Hydrologic Model (VIC) and the Community Land Model (CLM). Temporal variations in soil moisture content at 5, 20 and 50 cm depth in the Rollesbroich experimental watershed in Germany are simulated in both LSMs. Data assimilation (DA) provides a good way to jointly estimate soil moisture content and soil properties of the resolved soil domain. Four DA methods combined with the two LSMs are used in our work: the Ensemble Kalman Filter (EnKF) using state augmentation or dual estimation, the Residual Resampling Particle Filter (RRPF) and Markov chain Monte Carlo Particle Filter (MCMCPF). These four DA methods are tuned and calibrated for a five month period, and subsequently evaluated for another five month period. Performances of the two LSMs and the four DA methods are compared. Our results show that all DA methods improve the estimation of soil moisture content of the VIC and CLM models, especially if the soil hydraulic properties (VIC), the maximum baseflow velocity (VIC) and/or soil texture (CLM) are jointly estimated with soil moisture content. The augmentation and dual estimation methods performed slightly better than RRPF and MCMCPF in the evaluation period. The differences in simulated soil moisture content between CLM and VIC were larger than variations among the DA methods. The CLM performed better than the VIC model. The strong underestimation of soil moisture content in the third layer of the VIC model is likely related to an inadequate parameterization of groundwater drainage.

  6. Shear velocity model for the Kyrgyz Tien Shan from joint inversion of receiver function and surface wave data

    NASA Astrophysics Data System (ADS)

    Gilligan, Amy; Roecker, Steven W.; Priestley, Keith F.; Nunn, Ceri

    2014-10-01

    The Tien Shan is the largest active intracontinental orogenic belt on Earth. To better understand the processes causing mountains to form at great distances from a plate boundary, we analyse passive source seismic data collected on 40 broad-band stations of the MANAS project (2005-2007) and 12 stations of the permanent KRNET seismic network to determine variations in crustal thickness and shear wave speed across the range. We jointly invert P- and S-wave receiver functions with surface wave observations from both earthquakes and ambient noise to reduce the ambiguity inherent in the images obtained from the techniques applied individually. Inclusion of ambient noise data improves constraints on the upper crust by allowing dispersion measurements to be made at shorter periods. Joint inversion can also reduce the ambiguity in interpretation by revealing the extent to which various features in the receiver functions are amplified or eliminated by interference from multiples. The resulting wave speed model shows a variation in crustal thickness across the range. We find that crustal velocities extend to ˜75 km beneath the Kokshaal Range, which we attribute to underthrusting of the Tarim Basin beneath the southern Tien Shan. This result supports the plate model of intracontinental convergence. Crustal thickness elsewhere beneath the range is about 50 km, including beneath the Naryn Valley in the central Tien Shan where previous studies reported a shallow Moho. This difference apparently is the result of wave speed variations in the upper crust that were not previously taken into account. Finally, a high velocity lid appears in the upper mantle of the Central and Northern part of the Tien Shan, which we interpret as a remnant of material that may have delaminated elsewhere under the range.

  7. [Therapeutic algorithm for traumatic cartilage injuries].

    PubMed

    Miltner, Oliver; Hagemann, Lars; Ristan, Steven; Siebert, Christian H

    2009-02-01

    Reports regarding sport injuries frequently pertain to the knee. Although ligament and meniscus damage are the most common, cartilage injuries are of great interest. Even with the great variety of treatment modalities available, the healing of these cartilage injuries remains problematic. Due to the complex structure of hyaline cartilage joint surface, repair has proven to be very difficult. The conservative treatment options range from orthotic devices and physical therapy to systemic and intraarticular medication. In case of failure, a wide variety of surgical interventions exist. Among these surgical treatment forms, one must differentiate between the repair and the reconstruction of hyaline joint surfaces. In the latter group only the osteochondral autologous transplantation procedures allow for the reconstruction of a cartilaginous lesion with hyaline cartilage as part of a single procedure. This paper will provide an overview of most common therapeutic approaches to cartilage injuries available today. Even with the ongoing discussions with regard to cartilage healing, the basics such as the ligamentous stability of the affected joint, the mechanical axis of the extremity and good neuromuscular control must always be part of the algorithm.

  8. The Crust and Upper Mantle Structure of Northeastern Iran from Joint Waveform Tomography Imaging of Body and Surface Waves

    NASA Astrophysics Data System (ADS)

    Baker, B.; Roecker, S. W.; Priestley, K. F.; Tatar, M.

    2012-12-01

    The deformation resulting from the Arabian-Eurasian collision at the longitude of Iran is concentrated in the Zagros, Alborz and Kopeh Dagh Mountains. The Zagros and Alborz Mountains have been the focus of a number of studies but little is known about the structure of NE Iran and the Kopeh Dagh. The Kopeh Dagh form a linear intracontinental fold-and-thrust belt trending NW-SE between the stable Turkmenistan platform and Central Iran, and mark the northern limit to deformation in NE Iran. To the south of the Kopeh Dagh lie a series of elongated mountain ranges: the Binalud, which is a structural and geological eastward continuation of the Alborz, the Siah Kuh near Sabzevar and the Kuh-e-Sorkh near Kashmar. Between August 2006 and February 2008 we operated 17 broadband seismographs along a profile from Sarakhs, near the northeastern political border of Iran with Turkmenistan, across the Kopeh Dagh Mountains, to Yazd in Central Iran. We apply a combination of the teleseismic body wave waveform tomography technique of Roecker et al (2010) with an extension of this technique to surface waves (Roecker et al, 2011) to analyze this data to determine the elastic wavespeed structure of this area. The joint inversion of these different types of waves affords similar types of advantages that are common to combined surface wave dispersion/receiver function inversions in compensating for intrinsic weaknesses in horizontal and vertical resolution capabilities. We compare results recovered from a several different inverse methods, starting with simple gradient techniques to the more sophisticated pseudo-Hessian or L-BFGS approach, and find that the latter are generally more robust. Modelling of receiver functions and surface wave dispersion prior to the analysis is shown to be an efficacious way to generate starting models for this analysis.

  9. Seismic Tomography of the Continental United States from a Joint Inversion of Surface Waves and Body Waves

    NASA Astrophysics Data System (ADS)

    Golos, E. M.; Yao, H.; Zhang, H.; Fang, H.; Burdick, S.; Schaeffer, A. J.; Vernon, F.; Lebedev, S.; van der Hilst, R. D.

    2015-12-01

    We present a model of seismic velocity anomalies for the entire continental United States—coast to coast, surface to lower mantle—using a joint body wave-surface wave inversion. This technique (Zhang et al., 2014), performed on a global adaptively-spaced grid, exploits the good vertical resolution at shallow depths of surface wave data, and the sampling of the deep mantle by teleseismic body (P and S) waves. The resultant model has better resolution at all depths than either method alone, enabling evaluation of interactions between lithospheric and mantle processes. We utilize the depth-dependence of surface wave sensitivity kernels to express surface wave phase velocity data directly in terms of spatial velocity structure (Fang et al., 2015). The data used are Rayleigh wave phase velocities from earthquakes and ambient noise (Schaeffer and Lebedev, 2013; Ekström, 2014) and S phase travel times from USArray, measured at the Array National Facility (ANF). We include a suite of synthetic tests to verify the performance of the inversion and compare it to results from traditional tomographic methods. We also use P arrivals and the influence of Vp on Rayleigh wave propagation speed to generate a preliminary model of Vp variations, independent from but consistent with the Vs model. Our model corroborates the well-established pattern of slow anomalies in the western US, especially in the Basin and Range and Rio Grande Rift regions. New details emerge in the eastern US, thanks to increasing data from the region. A distinction is observed between widespread fast lithospheric anomalies, associated with stable cratonic material, and deeper fast features, associated with the remnants of the Farallon Plate. It has been proposed that these fragments, near the mantle transition zones, still affect mantle dynamics (Forte et al., 2007), so better resolution of these anomalies is an important advancement. In addition, slower velocities are observed beneath the Appalachians and

  10. Lithospheric Structure in Eastern Africa and the Arabian Plate from Joint Inversion of Surface Wave Dispersion Data and Receiver Functions

    NASA Astrophysics Data System (ADS)

    Dugda, M. T.; Nyblade, A. A.; Rodgers, A.; Al-Amri, A.; Julia, J.

    2006-12-01

    Lithospheric structure beneath Eastern Africa (Ethiopia, Kenya, and Djibouti) and the Arabian Shield and Platform has been investigated using a joint inversion of receiver functions and surface wave dispersion measurements from 10 to 175 s. Our models help to constrain the extent of modification made to the lithosphere in the region by hotspot tectonism. Most of the data for this study come from three major sources: the Ethiopia and Kenya Broadband Seismic Experiments which were carried out between 2000-2002 and 2001-2002, respectively, and data from the Saudi Arabia National Digital Seismic Network (KACST). We find that there is little or no seismic lid under the Main Ethiopian Rift and Afar. The results for the Ethiopian Plateau show that there has been thinning of the lithosphere by about ~30 40 km from typical Mozambique Belt lithosphere under Tanzania, which was reported to be up to 120 km thick, and that there has been a reduction in maximum shear wave velocity of the lid by about 7%. Replacement of the bottom of the former Mozambique Belt lithosphere by warm plume material with a partial erosion of the lithosphere can explain both the thinning of the lithosphere and the reduction of maximum velocity. Preliminary results suggest similar lithospheric structure beneath the Arabian Shield. The results from Kenya are similar to that of the results for the Mozambique Belt Lithosphere in Tanzania, showing 100-120 km thick lithosphere.

  11. Prosthetic Joint Infection Diagnosis Using Broad-Range PCR of Biofilms Dislodged from Knee and Hip Arthroplasty Surfaces Using Sonication

    PubMed Central

    Gomez, Eric; Cazanave, Charles; Cunningham, Scott A.; Greenwood-Quaintance, Kerryl E.; Steckelberg, James M.; Uhl, James R.; Hanssen, Arlen D.; Karau, Melissa J.; Schmidt, Suzannah M.; Osmon, Douglas R.; Berbari, Elie F.; Mandrekar, Jayawant

    2012-01-01

    Periprosthetic tissue and/or synovial fluid PCR has been previously studied for prosthetic joint infection (PJI) diagnosis; however, few studies have assessed the utility of PCR on biofilms dislodged from the surface of explanted arthroplasties using vortexing and sonication (i.e., sonicate fluid PCR). We compared sonicate fluid 16S rRNA gene real-time PCR and sequencing to culture of synovial fluid, tissue, and sonicate fluid for the microbiologic diagnosis of PJI. PCR sequences generating mixed chromatograms were decatenated using RipSeq Mixed. We studied sonicate fluids from 135 and 231 subjects with PJI and aseptic failure, respectively. Synovial fluid, tissue, and sonicate fluid culture and sonicate fluid PCR had similar sensitivities (64.7, 70.4, 72.6, and 70.4%, respectively; P > 0.05) and specificities (96.9, 98.7, 98.3, and 97.8%, respectively; P > 0.05). Combining sonicate fluid culture and PCR, the sensitivity was higher (78.5%, P < 0.05) than those of individual tests, with similar specificity (97.0%). Thirteen subjects had positive sonicate fluid culture but negative PCR, and 11 had negative sonicate fluid culture but positive PCR (among which 7 had prior use of antimicrobials). Broad-range PCR and culture of sonicate fluid have equivalent performance for PJI diagnosis. PMID:22895042

  12. Diamond-like carbon coatings enhance the hardness and resilience of bearing surfaces for use in joint arthroplasty.

    PubMed

    Roy, M E; Whiteside, L A; Xu, J; Katerberg, B J

    2010-04-01

    The purpose of this study was to evaluate the potential of a hard diamond-like carbon (DLC) coating to enhance the hardness and resilience of a bearing surface in joint replacement. The greater hardness of a magnesium-stabilized zirconium (Mg-PSZ) substrate was expected to provide a harder coating-substrate composite microhardness than the cobalt-chromium alloy (CoCr) also used in arthroplasty. Three femoral heads of each type (CoCr, Mg-PSZ, DLC-CoCr and DLC-Mg-PSZ) were examined. Baseline (non-coated) and composite coating/substrate hardness was measured by Vickers microhardness tests, while nanoindentation tests measured the hardness and elastic modulus of the DLC coating independent of the Mg-PSZ and CoCr substrates. Non-coated Mg-PSZ heads were considerably harder than non-coated CoCr heads, while DLC coating greatly increased the microhardness of the CoCr and Mg-PSZ substrates. On the nanoscale the non-coated heads were much harder than on the microscale, with CoCr exhibiting twice as much plastic deformation as Mg-PSZ. The mechanical properties of the DLC coatings were not significantly different for both the CoCr and Mg-PSZ substrates, producing similar moduli of resilience and plastic resistance ratios. DLC coatings greatly increased hardness on both the micro and nano levels and significantly improved resilience and resistance to plastic deformation compared with non-coated heads. Because Mg-PSZ allows less plastic deformation than CoCr and provides a greater composite microhardness, DLC-Mg-PSZ will likely be more durable for use as a bearing surface in vivo.

  13. Gait efficiency on an uneven surface is associated with falls and injury in older subjects with a spectrum of lower limb neuromuscular function: a prospective study

    PubMed Central

    Zurales, Katie; DeMott, Trina K.; Kim, Hogene; Allet, Lara; Ashton-Miller, James A.; Richardson, James K.

    2015-01-01

    Objective To determine which gait measures on smooth and uneven surfaces predict falls and fall-related injuries in older subjects with diabetic peripheral neuropathy (DPN). Design Twenty-seven subjects (12 women) with a spectrum of peripheral nerve function ranging from normal to moderately severe DPN walked on smooth and uneven surfaces, with gait parameters determined by optoelectronic kinematic techniques. Falls and injuries were then determined prospectively over the following year. Results Seventeen subjects (62.9%) fell and 12 (44.4%) sustained a fall-related injury. As compared to non-fallers, the subject group reporting any fall, as well as the subject group reporting fall-related injury, demonstrated decreased speed, greater step width (SW), shorter step length (SL) and greater step-width-to-step-length ratio (SW:SL) on both surfaces. Uneven surface SW:SL was the strongest predictor of falls (pseudo-R2 = 0.65; p = .012) and remained so with inclusion of other relevant variables into the model. Post-hoc analysis comparing injured with non-injured fallers showed no difference in any gait parameter. Conclusion SW:SL on an uneven surface is the strongest predictor of falls and injuries in older subjects with a spectrum of peripheral neurologic function. Given the relationship between SW:SL and efficiency, older neuropathic patients at increased fall risk appear to sacrifice efficiency for stability on uneven surfaces. PMID:26053187

  14. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data in the Wavelet Domain Constrained by Sparsity Regularization

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Fang, H.; Yao, H.; Maceira, M.; van der Hilst, R. D.

    2014-12-01

    Recently, Zhang et al. (2014, Pure and Appiled Geophysics) have developed a joint inversion code incorporating body-wave arrival times and surface-wave dispersion data. The joint inversion code was based on the regional-scale version of the double-difference tomography algorithm tomoDD. The surface-wave inversion part uses the propagator matrix solver in the algorithm DISPER80 (Saito, 1988) for forward calculation of dispersion curves from layered velocity models and the related sensitivities. The application of the joint inversion code to the SAFOD site in central California shows that the fault structure is better imaged in the new model, which is able to fit both the body-wave and surface-wave observations adequately. Here we present a new joint inversion method that solves the model in the wavelet domain constrained by sparsity regularization. Compared to the previous method, it has the following advantages: (1) The method is both data- and model-adaptive. For the velocity model, it can be represented by different wavelet coefficients at different scales, which are generally sparse. By constraining the model wavelet coefficients to be sparse, the inversion in the wavelet domain can inherently adapt to the data distribution so that the model has higher spatial resolution in the good data coverage zone. Fang and Zhang (2014, Geophysical Journal International) have showed the superior performance of the wavelet-based double-difference seismic tomography method compared to the conventional method. (2) For the surface wave inversion, the joint inversion code takes advantage of the recent development of direct inversion of surface wave dispersion data for 3-D variations of shear wave velocity without the intermediate step of phase or group velocity maps (Fang et al., 2014, Geophysical Journal International). A fast marching method is used to compute, at each period, surface wave traveltimes and ray paths between sources and receivers. We will test the new joint

  15. A new algorithm for three-dimensional joint inversion of body wave and surface wave data and its application to the Southern California plate boundary region

    NASA Astrophysics Data System (ADS)

    Fang, Hongjian; Zhang, Haijiang; Yao, Huajian; Allam, Amir; Zigone, Dimitri; Ben-Zion, Yehuda; Thurber, Clifford; van der Hilst, Robert D.

    2016-05-01

    We introduce a new algorithm for joint inversion of body wave and surface wave data to get better 3-D P wave (Vp) and S wave (Vs) velocity models by taking advantage of the complementary strengths of each data set. Our joint inversion algorithm uses a one-step inversion of surface wave traveltime measurements at different periods for 3-D Vs and Vp models without constructing the intermediate phase or group velocity maps. This allows a more straightforward modeling of surface wave traveltime data with the body wave arrival times. We take into consideration the sensitivity of surface wave data with respect to Vp in addition to its large sensitivity to Vs, which means both models are constrained by two different data types. The method is applied to determine 3-D crustal Vp and Vs models using body wave and Rayleigh wave data in the Southern California plate boundary region, which has previously been studied with both double-difference tomography method using body wave arrival times and ambient noise tomography method with Rayleigh and Love wave group velocity dispersion measurements. Our approach creates self-consistent and unique models with no prominent gaps, with Rayleigh wave data resolving shallow and large-scale features and body wave data constraining relatively deeper structures where their ray coverage is good. The velocity model from the joint inversion is consistent with local geological structures and produces better fits to observed seismic waveforms than the current Southern California Earthquake Center (SCEC) model.

  16. The spatial organisation of joint surface chondrocytes: review of its potential roles in tissue functioning, disease and early, preclinical diagnosis of osteoarthritis.

    PubMed

    Aicher, Wilhelm K; Rolauffs, Bernd

    2014-04-01

    Chondrocytes display within the articular cartilage depth-dependent variations of their many properties that are comparable to the depth-dependent changes of the properties of the surrounding extracellular matrix. However, not much is known about the spatial organisation of the chondrocytes throughout the tissue. Recent studies revealed that human chondrocytes display distinct spatial patterns of organisation within the articular surface, and each joint surface is dominated in a typical way by one of four basic spatial patterns. The resulting complex spatial organisations correlate with the specific diarthrodial joint type, suggesting an association of the chondrocyte organisation within the joint surface with the occurring biomechanical forces. In response to focal osteoarthritis (OA), the superficial chondrocytes experience a destruction of their spatial organisation within the OA lesion, but they also undergo a defined remodelling process distant from the OA lesion in the remaining, intact cartilage surface. One of the biological insights that can be derived from this spatial remodelling process is that the chondrocytes are able to respond in a generalised and coordinated fashion to distant focal OA. The spatial characteristics of this process are tremendously different from the cellular aggregations typical for OA lesions, suggesting differences in the underlying mechanisms. Here we summarise the available information on the spatial organisation of chondrocytes and its potential roles in cartilage functioning. The spatial organisation could be used to diagnose early OA onset before manifest OA results in tissue destruction and clinical symptoms. With further development, this concept may become clinically suitable for the diagnosis of preclinical OA.

  17. Lubrication of the human ankle joint in walking with the synovial fluid filtrated by the cartilage with the surface zone worn out: steady pure sliding motion.

    PubMed

    Hlavácek, M

    1999-10-01

    A mixture model of synovial fluid filtration by cartilage in the human ankle joint during walking is presented for steady sliding motion of the articular surfaces. In the paper the cartilage surface zone is assumed worn out. The same model has been recently applied to the squeeze-film problem for the human hip joint loaded by the body weight during standing (Hlavácek, Journal of Biomechanics 26, 1145-1150, 1151-1160, 1993; Hlavácek and Novák, Journal of Biomechanics 28, 1193-1198, 1199-1205, 1995). The linear biphasic model for cartilage (elastic porous matrix + ideal fluid) due to Prof. V. C. Mow and his co-workers and the biphasic model for synovial fluid (viscous fluid + ideal fluid), as used in the above-mentioned squeeze-film problem, are applied. For the physiologic parameters of the ankle joint during walking, a continuous synovial fluid film about 1 microm thick is maintained under steady entraining motion according to the classical model without the fluid transport across the articular surface. This is not the case in the filtration model with the cartilage surface zones worn out. On the contrary, this filtration model indicates that synovial fluid is intensively filtrated by such cartilage, so that no continuous fluid film is maintained and a synovial gel layer, about 10(-8) m thick, develops over the majority of the contact. Thus, if the cartilage surface zones are worn out, boundary lubrication should prevail in the ankle joint under steady sliding motion for the mean values of loading and the sliding velocity encountered in walking cycle.

  18. Changes in respiratory elastance after deep inspirations reflect surface film functionality in mice with acute lung injury.

    PubMed

    Takahashi, Ayuko; Bartolák-Suki, Erzsébet; Majumdar, Arnab; Suki, Béla

    2015-08-01

    Pulmonary surfactant reduces surface tension in the lung and prevents alveolar collapse. Following a deep inspiration (DI), respiratory elastance first drops then gradually increases due to surface film and tissue viscoelasticity. In acute lung injury (ALI), this increase is faster and governed by alveolar collapse due to increased surface tension. We hypothesized that the rate of increase in elastance reflects the deficiency of surfactant in the lung. To test this, mice were ventilated before (baseline) and after saline lavage obtained by injecting 0.8 ml and withdrawing 0.7 ml fluid (severe ALI) or injecting 0.1 ml (mild ALI). After two DIs, elastance was tracked for 10 min followed by a full lavage to assess surfactant proteins B (SP-B) and C (SP-C) content. Following 2 DIs, the increases in elastance during 10 min ventilation (ΔH) were 3.60 ± 0.61, 5.35 ± 1.04, and 8.33 ± 0.84 cmH2O/ml in baseline mice and mice with mild and severe ALI, respectively (P < 0.0001). SP-B and SP-C in the lavage fluid dropped by 32.4% and 24.9% in the mild and 50.4% and 39.6% in the severe ALI, respectively. Furthermore, ΔH showed a strong negative correlation with both SP-B (r(2) = 0.801) and SP-C (r(2) = 0.810) content. The ΔH was, however, much smaller when the lavage fluid also contained exogeneous SP-B and SP-C. Thus ΔH can be interpreted as an organ level measure of surface film functionality in lavage-induced ALI in mice. This method could prove useful in clinical situations such as diagnosing surfactant problems, monitoring recovery from lung injury or the effectiveness of surfactant therapy.

  19. Changes in respiratory elastance after deep inspirations reflect surface film functionality in mice with acute lung injury

    PubMed Central

    Takahashi, Ayuko; Majumdar, Arnab; Suki, Béla

    2015-01-01

    Pulmonary surfactant reduces surface tension in the lung and prevents alveolar collapse. Following a deep inspiration (DI), respiratory elastance first drops then gradually increases due to surface film and tissue viscoelasticity. In acute lung injury (ALI), this increase is faster and governed by alveolar collapse due to increased surface tension. We hypothesized that the rate of increase in elastance reflects the deficiency of surfactant in the lung. To test this, mice were ventilated before (baseline) and after saline lavage obtained by injecting 0.8 ml and withdrawing 0.7 ml fluid (severe ALI) or injecting 0.1 ml (mild ALI). After two DIs, elastance was tracked for 10 min followed by a full lavage to assess surfactant proteins B (SP-B) and C (SP-C) content. Following 2 DIs, the increases in elastance during 10 min ventilation (ΔH) were 3.60 ± 0.61, 5.35 ± 1.04, and 8.33 ± 0.84 cmH2O/ml in baseline mice and mice with mild and severe ALI, respectively (P < 0.0001). SP-B and SP-C in the lavage fluid dropped by 32.4% and 24.9% in the mild and 50.4% and 39.6% in the severe ALI, respectively. Furthermore, ΔH showed a strong negative correlation with both SP-B (r2 = 0.801) and SP-C (r2 = 0.810) content. The ΔH was, however, much smaller when the lavage fluid also contained exogeneous SP-B and SP-C. Thus ΔH can be interpreted as an organ level measure of surface film functionality in lavage-induced ALI in mice. This method could prove useful in clinical situations such as diagnosing surfactant problems, monitoring recovery from lung injury or the effectiveness of surfactant therapy. PMID:26066828

  20. The effect of the dimensions of the distal femur and proximal tibia joint surfaces on the development of knee osteoarthritis.

    PubMed

    Işik, Derya; Işik, Çetin; Apaydin, Nihal; Üstü, Yusuf; Uğurlu, Mahmut; Bozkurt, Murat

    2015-07-01

    The aim of this study was to determine whether the dimensions of the distal femur and proximal tibia joint surfaces affect the etiology of knee osteoarthritis (OA). The study comprised the records of 1,324 patients who had been admitted to hospital with knee pain. Anterioposterior (AP) and lateral radiographs of the knee were taken. Using the Kellgren-Lawrence Scale, the patient group comprised Stages 2, 3, and 4 radiographs and the controls comprised Stages 0 and 1 radiographs. Four lengths were measured for each patient in both groups: femur mediolateral (femur ML), tibia mediolateral (tibia ML), femur anteroposterior (femur AP), and tibia anteroposterior (tibia AP). Osteophytes were not included in the measurements in the patient group. All the measurements were repeated by two researchers at two different times. The groups were compared in terms of these measurements and the correlations between them. The mean femur ML length was significantly greater in the patient group than the control group (P = 0.032) and the mean femur AP length was significantly less (P = 0.037). In addition, the difference between the femur ML and AP lengths was significantly high in the patient group (P < 0.001). The difference between the tibia and femur ML lengths was significantly high in the patient group (P < 0.001) and the difference between the tibia and femur AP lengths was higher in the control group (P = 0.001). A longer femur ML and a shorter femur AP, together with a greater difference between these two lengths and a greater difference between the tibia ML and femur ML lengths, could be a risk factor for developing knee OA. More extensive anatomical and biomechanical studies in the future will enable these results to be corroborated.

  1. Exercise and the Knee Joint.

    ERIC Educational Resources Information Center

    Clarke, H. Harrison, Ed.

    1976-01-01

    This report by the President's Council on Physical Fitness and Sports examines the effects of various forms of physical exercise on the knee joint which, because of its vulnerability, is especially subject to injury. Discussion centers around the physical characteristics of the joint, commonly used measurements for determining knee stability,…

  2. Arm Injuries and Disorders

    MedlinePlus

    ... of them are in your arm; the humerus, radius and ulna. Your arms are also made up of muscles, joints, tendons and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall or an accident. Types of arm injuries ...

  3. Leg Injuries and Disorders

    MedlinePlus

    ... legs. Common leg injuries include sprains and strains, joint dislocations, and fractures. These injuries can affect the entire leg, or just the foot, ankle, knee, or hip. Certain diseases also lead to leg problems. For example, knee osteoarthritis, common in older people, can cause pain and ...

  4. Examining the knee joint.

    PubMed

    Monk, Daniel

    2013-04-01

    Appropriate history taking and examination can ensure accurate diagnosis of common knee problems, and rapid and effective interventions or referral to orthopaedic specialists. This article describes the anatomy of the knee joint and discusses relevant history taking, the examination process, special tests and radiology, as well as common knee injuries and their management.

  5. Prediction of the Properties of Heat-Affected Zone of Welded Joints of Sheets from Aluminum Alloys with Structured Surface

    NASA Astrophysics Data System (ADS)

    Mikhailov, V. G.

    2016-05-01

    Welded joints of light structured sheets from aluminum alloy EN AW-6181-T4 (DIN EN 515) of the Al - Si - Mg system are studied. The welding is performed in an argon environment with a short arc by the method of cold metal transfer (CMT®). The results of the study are used in an amended Leblond model for describing the variation of the properties of the heat-affected zone of welded joints of structured sheets.

  6. Surface-modified particles loaded with CaMKII inhibitor protect cardiac cells against mitochondrial injury.

    PubMed

    Wongrakpanich, Amaraporn; Morris, Angie S; Geary, Sean M; Joiner, Mei-Ling A; Salem, Aliasger K

    2017-03-30

    An excess of calcium (Ca(2+)) influx into mitochondria during mitochondrial re-energization is one of the causes of myocardial cell death during ischemic/reperfusion injury. This overload of Ca(2+) triggers the mitochondrial permeability transition pore (mPTP) opening which leads to programmed cell death. During the ischemic/reperfusion stage, the activated Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) enzyme is responsible for Ca(2+) influx. To reduce CaMKII-related cell death, sub-micron particles composed of poly(lactic-co-glycolic acid) (PLGA), loaded with a CaMKII inhibitor peptide were fabricated. The CaMKII inhibitor peptide-loaded (CIP) particles were coated with a mitochondria targeting moiety, triphenylphosphonium cation (TPP), which allowed the particles to accumulate and release the peptide inside mitochondria to inhibit CaMKII activity. The fluorescently labeled TPP-CIP was taken up by mitochondria and successfully reduced reactive oxygen species (ROS) caused by Isoprenaline (ISO) in a differentiated rat cardiomyocyte-like cell line. When cells were treated with TPP-CIP prior to ISO exposure, they maintained mitochondrial membrane potential. The TPP-CIP protected cells from ISO-induced ROS production and decreased mitochondrial membrane potential. Thus, TPP-CIP has the potential to be used in protection against ischemia/reperfusion injury.

  7. Erythrocyte Aggregation due to Surface Nanobubble Interactions During the Onset of Thermal Burn Injury

    NASA Astrophysics Data System (ADS)

    Seidner, Harrison S.

    Red Blood Cell (RBC) aggregation is an important hemorheological phenomenon especially in microcirculation. In healthy individuals, RBCs are known to aggregate and gravitate toward the faster flow in the center of vessels to increase their throughput for more efficient oxygen delivery. Their aggregation is known to occur during a variety of environmental, pathological, and physiological conditions and is reversible when aggregates are subject to the relatively high shear forces in the circulation. The likelihood that aggregates will monodisperse in flow is dependent on the conditions during which they form. In situations where such aggregates are not sheared to monodispersion their presence can impact the perfusion of microvascular networks. More specifically, aggregates subject to the low shear rates in the zone of stasis near regions of thermal burn injury are capable of occluding vessels in the microcirculation and inhibiting the delivery of oxygen and nutrients to tissue downstream. The basic mechanism leading to erythrocyte aggregation at the onset of thermal injury is unknown. This dissertation investigates parameters involved in erythrocyte aggregation, methods of measuring and testing erythrocyte aggregation, and incorporates modeling based on first principles ultimately to propose a mechanism of this phenomenon.

  8. Injury in rugby league.

    PubMed

    Hoskins, W; Pollard, H; Hough, K; Tully, C

    2006-05-01

    It was the purpose of this review to document the range, incidence, location and mechanism of injury occurring in the sport of rugby league. Rugby league is a collision sport played in Europe and the Pacific regions including Australia. The sport is well established and has competitions ranging from junior to elite professional. Due to the contact nature of the game, injury is relatively common. The most common injuries are musculotendinous in nature and afflict the lower limb more frequently than elsewhere. Despite the high incidence of minor (sprains/strains) to moderate musculoskeletal injury (fracture, ligament and joint injury) and minor head injuries such as lacerations, nasal fractures and concussions, rare more serious spinal cord and other injuries causing death have also been recorded. The literature on rugby league injury is small but growing and suffers from a lack of consistent definition of what an injury is, thereby causing variability in the nature and incidence/prevalence of injury. Information is lacking on the injury profiles of different age groups. Importantly, there has been little attempt to establish a coordinated injury surveillance program in rugby league in the junior or professional levels. The implementation of such programs would require a universal definition of injury and a focus on important events and competitions. The implementation could provide important information in the identification and prevention of risk factors for injury.

  9. Sonocatalytic injury of cancer cells attached on the surface of a nickel-titanium dioxide alloy plate.

    PubMed

    Ninomiya, Kazuaki; Maruyama, Hirotaka; Ogino, Chiaki; Takahashi, Kenji; Shimizu, Nobuaki

    2016-01-01

    The present study demonstrates ultrasound-induced cell injury using a nickel-titanium dioxide (Ni-TiO2) alloy plate as a sonocatalyst and a cell culture surface. Ultrasound irradiation of cell-free Ni-TiO2 alloy plates with 1 MHz ultrasound at 0.5 W/cm(2) for 30s led to an increased generation of hydroxyl (OH) radicals compared to nickel-titanium (Ni-Ti) control alloy plates with and without ultrasound irradiation. When human breast cancer cells (MCF-7 cells) cultured on the Ni-TiO2 alloy plates were irradiated with 1 MHz ultrasound at 0.5 W/cm(2) for 30s and then incubated for 48 h, cell density on the alloy plate was reduced to approximately 50% of the controls on the Ni-Ti alloy plates with and without ultrasound irradiation. These results indicate the injury of MCF-7 cells following sonocatalytic OH radical generation by Ni-TiO2. Further experiments demonstrated cell shrinkage and chromatin condensation after ultrasound irradiation of MCF-7 cells attached on the Ni-TiO2 alloy plates, indicating induction of apoptosis.

  10. Eye Injuries (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Eye Injuries KidsHealth > For Parents > Eye Injuries Print A ... sand, dirt, and other foreign bodies on the eye surface) Wash your hands thoroughly before touching the ...

  11. 49 CFR 225.23 - Joint operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Joint operations. 225.23 Section 225.23....23 Joint operations. (a) Any reportable death, injury, or illness of an employee arising from an accident/incident involving joint operations must be reported on Form FRA F 6180.55a by the...

  12. 49 CFR 225.23 - Joint operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Joint operations. 225.23 Section 225.23....23 Joint operations. (a) Any reportable death, injury, or illness of an employee arising from an accident/incident involving joint operations must be reported on Form FRA F 6180.55a by the...

  13. 49 CFR 225.23 - Joint operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Joint operations. 225.23 Section 225.23....23 Joint operations. (a) Any reportable death, injury, or illness of an employee arising from an accident/incident involving joint operations must be reported on Form FRA F 6180.55a by the...

  14. 49 CFR 225.23 - Joint operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Joint operations. 225.23 Section 225.23....23 Joint operations. (a) Any reportable death, injury, or illness of an employee arising from an accident/incident involving joint operations must be reported on Form FRA F 6180.55a by the...

  15. 49 CFR 225.23 - Joint operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Joint operations. 225.23 Section 225.23....23 Joint operations. (a) Any reportable death, injury, or illness of an employee arising from an accident/incident involving joint operations must be reported on Form FRA F 6180.55a by the...

  16. Surface electromyographic patterns of masticatory, neck, and trunk muscles in temporomandibular joint dysfunction patients undergoing anterior repositioning splint therapy.

    PubMed

    Tecco, Simona; Tetè, Stefano; D'Attilio, Michele; Perillo, Letizia; Festa, Felice

    2008-12-01

    The aim of this study was to investigate the surface electromyographic (sEMG) activity of neck, trunk, and masticatory muscles in subjects with temporomandibular joint (TMJ) internal derangement treated with anterior mandibular repositioning splints. sEMG activities of the muscles in 34 adult subjects (22 females and 12 males; mean age 30.4 years) with TMJ internal derangement were compared with a control group of 34 untreated adults (20 females and 14 males; mean age 31.8 years). sEMG activities of seven muscles (anterior and posterior temporalis, masseter, posterior cervicals, sternocleidomastoid, and upper and lower trapezius) were studied bilaterally, with the mandible in the rest position and during maximal voluntary clenching (MVC), at the beginning of therapy (T0) and after 10 weeks of treatment (T1). Paired and Student's t-tests were undertaken to determine differences between the T0 and T1 data and in sEMG activity between the study and control groups. At T0, paired masseter, sternocleidomastoid, and cervical muscles, in addition to the left anterior temporal and right lower trapezius, showed significantly greater sEMG activity (P = 0.0001; P = 0.0001; for left cervical, P = 0.03; for right cervical, P = 0.0001; P = 0.006 and P = 0.007 muscles, respectively) compared with the control group. This decreased over the remaining study period, such that after treatment, sEMG activity revealed no statistically significant difference when compared with the control group. During MVC at T0, paired masseter and anterior and posterior temporalis muscles showed significantly lower sEMG activity (P = 0.03; P = 0.005 and P = 0.04, respectively) compared with the control group. In contrast, at T1 sEMG activity significantly increased (P = 0.02; P = 0.004 and P = 0.04, respectively), but no difference was observed in relation to the control group. Splint therapy in subjects with internal disk derangement seems to affect sEMG activity of the masticatory, neck, and trunk

  17. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

    PubMed Central

    Anasane, Nayana; Ahirrao, Yogesh; Chitnis, Deepa; Meshram, Suresh

    2013-01-01

    Background: Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. Materials and Methods: A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Results: Transverse strength values for all repaired groups were significantly lower than those for the control group (P < 0.001) (88.77 MPa), with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa) which was significantly superior to the other joint surface contours (P < 0.001). Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin (P < 0.001). Conclusion: Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins. PMID:23946739

  18. Mechanics of Sheeting Joints

    NASA Astrophysics Data System (ADS)

    Martel, S. J.

    2015-12-01

    Physical breakdown of rock across a broad scale spectrum involves fracturing. In many areas large fractures develop near the topographic surface, with sheeting joints being among the most impressive. Sheeting joints share many geometric, textural, and kinematic features with other joints (opening-mode fractures) but differ in that they are (a) discernibly curved, (b) open near the topographic surface, and (c) form subparallel to the topographic surface. Where sheeting joints are geologically young, the surface-parallel compressive stresses are typically several MPa or greater. Sheeting joints are best developed beneath domes, ridges, and saddles; they also are reported, albeit rarely, beneath valleys or bowls. A mechanism that accounts for all these associations has been sought for more than a century: neither erosion of overburden nor high lateral compressive stresses alone suffices. Sheeting joints are not accounted for by Mohr-Coulomb shear failure criteria. Principles of linear elastic fracture mechanics, together with the mechanical effect of a curved topographic surface, do provide a basis for understanding sheeting joint growth and the pattern sheeting joints form. Compressive stresses parallel to a singly or doubly convex topographic surface induce a tensile stress perpendicular to the surface at shallow depths; in some cases this alone could overcome the weight of overburden to open sheeting joints. If regional horizontal compressive stresses, augmented by thermal stresses, are an order of magnitude or so greater than a characteristic vertical stress that scales with topographic amplitude, then topographic stress perturbations can cause sheeting joints to open near the top of a ridge. This topographic effect can be augmented by pressure within sheeting joints arising from water, ice, or salt. Water pressure could be particularly important in helping drive sheeting joints downslope beneath valleys. Once sheeting joints have formed, the rock sheets between

  19. Joint assimilation of Aquarius-derived sea surface salinity and AVHRR-derived sea surface temperature in an ocean general circulation model using SEEK filter: Implication for mixed layer depth and barrier layer thickness

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhisek; Sharma, Rashmi; Kumar, Raj; Basu, Sujit

    2015-10-01

    Sea surface salinity (SSS) from Aquarius mission and sea surface temperature (SST) from Advanced Very High Resolution Radiometer (AVHRR) for the years 2012-2014 are assimilated into the global Massachusetts Institute of Technology General Circulation Model (MITGCM). Investigation of the impact of assimilation of these two data sets on simulated mixed layer depth (MLD) and barrier layer thickness (BLT) forms the core of our study. The method of assimilation is the Singular Evolutive Extended Kalman (SEEK) filter. Several assimilation runs are performed. Single-parameter assimilation, as well as joint assimilation, is conducted. To begin with, the model simulated SST and SSS are compared with independent Argo observations of these two parameters. Use of latitudinally varying error variances, which is a novel feature of our study, gives rise to the significant improvement in the simulation of SSS and SST. The best result occurs when joint assimilation is performed. Afterward, simulated MLD and BLT are compared with the same parameters derived from Argo observations forming an independent validation data set. Comparisons are performed both in temporal and spatial domains. Significant positive impact of assimilation is found in all the cases studied, and joint assimilation is found to outperform single-parameter assimilation in each of the cases considered. It is found that simulations of MLD and BLT improve up to 24% and 29%, respectively, when a joint assimilation of SSS and SST is carried out.

  20. Relipidated tissue factor linked to collagen surfaces potentiates platelet adhesion and fibrin formation in a microfluidic model of vessel injury

    PubMed Central

    Colace, Thomas V.; Jobson, Jennielle; Diamond, Scott L.

    2011-01-01

    Microfluidic devices allow for the controlled perfusion of human or mouse blood over defined prothrombotic surfaces at venous and arterial shear rates. To mimic in vivo injuries such a plaque rupture, the need exists to link lipidated tissue factor (TF) to surface bound collagen fibers. Recombinant TF was relipidated in liposomes of phosphatidylserine/phosphatidylcholine/biotin-linked phosphatidylethanolamine (20:79:1 PS:PC:bPE molar ratio). Collagen was patterned in a 250-micron wide stripe and labeled with biotinylated anti-collagen antibody which was then bound with streptavidin, allowing the subsequent capture of the TF liposomes. To verify and detect the TF liposome-collagen assembly, individual molecular complexes of TF-factor VIIa on collagen were visualized using the Proximity Ligation Assay (PLA) to produce discretely localized fluorescent events that were strictly dependent on the presence of factor VIIa and primary antibodies against TF or factor VIIa. Perfusion for 450 sec (wall shear rate, 200 s−1) of corn trypsin inhibitor (CTI, a factor XIIa inhibitor) treated whole blood over the stripe of TF-collagen enhanced platelet adhesion by 30 ± 8% (p < 0.001) and produced measurable fibrin (>50-fold increase) as compared to surfaces lacking TF. PS:PC:bPE liposomes lacking TF resulted in no enhancement of platelet deposition. Essentially no fibrin was formed during perfusion over collagen surfaces or collagen surfaces with liposomes lacking TF despite the robust platelet deposition, indicating a lack of kinetically significant platelet-borne tissue factor in healthy donor blood. This study demonstrates a reliable approach to link functionally-active TF to collagen for microfluidic thrombosis studies. PMID:21902184

  1. A joint data assimilation system (Tan-Tracker) to simultaneously estimate surface CO2 fluxes and 3-D atmospheric CO2 concentrations from observations

    NASA Astrophysics Data System (ADS)

    Tian, X.; Xie, Z.; Liu, Y.; Cai, Z.; Fu, Y.; Zhang, H.; Feng, L.

    2013-09-01

    To quantitatively estimate CO2 surface fluxes (CFs) from atmospheric observations, a joint data assimilation system ("Tan-Tracker") is developed by incorporating a joint data assimilation framework into the GEOS-Chem atmospheric transport model. In Tan-Tracker, we choose an identity operator as the CF dynamical model to describe the CFs' evolution, which constitutes an augmented dynamical model together with the GEOS-Chem atmospheric transport model. In this case, the large-scale vector made up of CFs and CO2 concentrations is taken as the prognostic variable for the augmented dynamical model. And thus both CO2 concentrations and CFs are jointly assimilated by using the atmospheric observations (e.g., the in-situ observations or satellite measurements). In contrast, in the traditional joint data assimilation frameworks, CFs are usually treated as the model parameters and form a state-parameter augmented vector jointly with CO2 concentrations. The absence of a CF dynamical model will certainly result in a large waste of observed information since any useful information for CFs' improvement achieved by the current data assimilation procedure could not be used in the next assimilation cycle. Observing system simulation experiments (OSSEs) are carefully designed to evaluate the Tan-Tracker system in comparison to its simplified version (referred to as TT-S) with only CFs taken as the prognostic variables. It is found that our Tan-Tracker system is capable of outperforming TT-S with higher assimilation precision for both CO2 concentrations and CO2 fluxes, mainly due to the simultaneous assimilation of CO2 concentrations and CFs in our Tan-Tracker data assimilation system.

  2. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data for Three-Dimensional Seismic Velocity Structure Around SAFOD

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Thurber, C. H.; Maceira, M.; Roux, P.

    2013-12-01

    The crust around the San Andreas Fault Observatory at depth (SAFOD) has been the subject of many geophysical studies aimed at characterizing in detail the fault zone structure and elucidating the lithologies and physical properties of the surrounding rocks. Seismic methods in particular have revealed the complex two-dimensional (2D) and three-dimensional (3D) structure of the crustal volume around SAFOD and the strong velocity reduction in the fault damage zone. In this study we conduct a joint inversion using body-wave arrival times and surface-wave dispersion data to image the P-and S-wave velocity structure of the upper crust surrounding SAFOD. The two data types have complementary strengths - the body-wave data have good resolution at depth, albeit only where there are crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution and are not dependent on the earthquake source distribution because they are derived from ambient noise. The body-wave data are from local earthquakes and explosions, comprising the dataset analyzed by Zhang et al. (2009). The surface-wave data are for Love waves from ambient noise correlations, and are from Roux et al. (2011). The joint inversion code is based on the regional-scale version of the double-difference (DD) tomography algorithm tomoDD. The surface-wave inversion code that is integrated into the joint inversion algorithm is from Maceira and Ammon (2009). The propagator matrix solver in the algorithm DISPER80 (Saito, 1988) is used for the forward calculation of dispersion curves from layered velocity models. We examined how the structural models vary as we vary the relative weighting of the fit to the two data sets and in comparison to the previous separate inversion results. The joint inversion with the 'optimal' weighting shows more clearly the U-shaped local structure from the Buzzard Canyon Fault on the west side of SAF to the Gold Hill Fault on the east side.

  3. Development of a Spring-Loaded Impact Device to Deliver Injurious Mechanical Impacts to the Articular Cartilage Surface

    PubMed Central

    Alexander, Peter G.; Song, Yingjie; Taboas, Juan M.; Chen, Faye H.; Melvin, Gary M.; Manner, Paul A.

    2013-01-01

    Objective: Traumatic impacts on the articular joint surface in vitro are known to lead to degeneration of the cartilage. The main objective of this study was to develop a spring-loaded impact device that can be used to deliver traumatic impacts of consistent magnitude and rate and to find whether impacts cause catabolic activities in articular cartilage consistent with other previously reported impact models and correlated with the development of osteoarthritic lesions. In developing the spring-loaded impactor, the operating hypothesis is that a single supraphysiologic impact to articular cartilage in vitro can affect cartilage integrity, cell viability, sulfated glycosaminoglycan and inflammatory mediator release in a dose-dependent manner. Design: Impacts of increasing force are delivered to adult bovine articular cartilage explants in confined compression. Impact parameters are correlated with tissue damage, cell viability, matrix and inflammatory mediator release, and gene expression 24 hours postimpact. Results: Nitric oxide release is first detected after 7.7 MPa impacts, whereas cell death, glycosaminoglycan release, and prostaglandin E2 release are first detected at 17 MPa. Catabolic markers increase linearly to maximal levels after ≥36 MPa impacts. Conclusions: A single supraphysiologic impact negatively affects cartilage integrity, cell viability, and GAG release in a dose-dependent manner. Our findings showed that 7 to 17 MPa impacts can induce cell death and catabolism without compromising the articular surface, whereas a 17 MPa impact is sufficient to induce increases in most common catabolic markers of osteoarthritic degeneration. PMID:26069650

  4. Pullout wire fixation together with distal interphalangeal joint Kirschner wire stabilization for acute combined tendon and bone (double level) mallet finger injury.

    PubMed

    Zhang, Xu; Shao, Xinzhong; Huang, Yong

    2015-02-01

    This article describes a previously unclassified type of combined tendon/bone mallet finger. This supplements the conventional Doyle classification. The article also describes the technique for surgical treatment of such mallet fingers, which involves the use of a pullout wire with K-wire stabilization of the distal interphalangeal joint.

  5. Biomechanics of whiplash injury.

    PubMed

    Chen, Hai-bin; Yang, King H; Wang, Zheng-guo

    2009-10-01

    Despite a large number of rear-end collisions on the road and a high frequency of whiplash injuries reported, the mechanism of whiplash injuries is not completely understood. One of the reasons is that the injury is not necessarily accompanied by obvious tissue damage detectable by X-ray or MRI. An extensive series of biomechanics studies, including injury epidemiology, neck kinematics, facet capsule ligament mechanics, injury mechanisms and injury criteria, were undertaken to help elucidate these whiplash injury mechanisms and gain a better understanding of cervical facet pain. These studies provide the following evidences to help explain the mechanisms of the whiplash injury: (1) Whiplash injuries are generally considered to be a soft tissue injury of the neck with symptoms such as neck pain and stiffness, shoulder weakness, dizziness, headache and memory loss, etc. (2) Based on kinematical studies on the cadaver and volunteers, there are three distinct periods that have the potential to cause injury to the neck. In the first stage, flexural deformation of the neck is observed along with a loss of cervical lordosis; in the second stage, the cervical spine assumes an S-shaped curve as the lower vertebrae begin to extend and gradually cause the upper vertebrae to extend; during the final stage, the entire neck is extended due to the extension moments at both ends. (3) The in vivo environment afforded by rodent models of injury offers particular utility for linking mechanics, nociception and behavioral outcomes. Experimental findings have examined strains across the facet joint as a mechanism of whiplash injury, and suggested a capsular strain threshold or a vertebral distraction threshold for whiplash-related injury, potentially producing neck pain. (4) Injuries to the facet capsule region of the neck are a major source of post-crash pain. There are several hypotheses on how whiplash-associated injury may occur and three of these injuries are related to strains

  6. Joint retrieval of surface reflectance and aerosol properties from MSG/SEVIRI observations in the framework of aerosol_CCI2

    NASA Astrophysics Data System (ADS)

    Damman, Alix; Zunz, Violette; Govaerts, Yves; Kaminski, Thomas; Voßbeck, Michael

    2016-04-01

    The Meteosat satellites play an important role for the generation of consistent long time series of aerosol properties. This importance relies on (i) the long duration of past (Meteosat First Generation, MFG), present (Meteosat Second Generation, MSG) and future (Meteosat Third Generation, MTG) missions and (ii) their frequent cycle of acquisition that can be used to document the anisotropy of the surface and therefore the lower boundary condition for aerosol retrieval over land surfaces. The Package for the joint Inversion of Surface and Aerosol (PISA) is a new algorithm developed by Rayference and The Inversion Lab for the joint retrieval of surface reflectance and aerosol properties. It relies on the inversion of a physically-based radiative transfer model accounting for the surface reflectance anisotropy and its coupling with aerosol scattering. The inversion scheme accounts for prior knowledge on the surface properties and smoothness constraints on the temporal variation of aerosols. PISA also provides the posterior uncertainty covariance matrix for the retrieved variables in every processed pixel. The package has been applied on Top Of Atmosphere (TOA) Bidirectional Reflectance Factor (BRF) acquired by SEVIRI onboard Meteosat Second Generation (MSG) in the VIS0.6, VIS0.8 and NIR1.6 spectral bands. Observations are accumulated during a certain period of time to sufficiently document the surface anisotropy and minimize the impact of clouds. The surface radiative properties are retrieved for this entire accumulation period during which they are supposed to be constant. Aerosol properties however are derived on an hourly basis. Based on PISA, a processing chain has been developed and applied on 2008 MSG/SEVIRI observations for some specific sub-domains of the Earth disk. For these processed sub-domains, the information content of each MSG/SEVIRI band will be analysed based on the prior and posterior uncertainty covariance matrices. This constitutes a first step

  7. Effect of adhesive thickness and surface treatment on shear strength on single lap joint Al/CFRP using adhesive of epoxy/Al fine powder

    NASA Astrophysics Data System (ADS)

    Diharjo, Kuncoro; Anwar, Miftahul; Tarigan, Roy Aries P.; Rivai, Ahmad

    2016-02-01

    The objective of this study is to investigate the effect of adhesive thickness and surface treatment on the shear strength and failure type characteristic of single lap joint (SLJ) CFRP/Al using adhesive epoxy/Al-fine-powder. The CFRP was produced by using hand layup method for 30% of woven roving carbon fiber (w/w) and the resin used was bisphenolic. The adhesive was prepared using 12.5% of aluminum fine powder (w/w) in the epoxy adhesive. The powder was mixed by using a mixing machine at 60 rpm for 6 minutes, and then it was used to join the Al plate-2024 and CFRP. The start time to pressure for the joint process was 20 minutes after the application of adhesive on the both of adherends. The variables in this research are adhesive thickness (i.e. 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm and 1 mm) and surface treatment of adherends (i.e. acetone, chromate sulphuric acid, caustic etch and tucker's reagent). Before shear testing, all specimens were post-cured at 100 °C for 15 minutes. The result shows that the SLJ has the highest shear strength for 0.4 mm of adhesive thickness. When the adhesive thickness is more than 0.4 mm (0.6-1 mm), the shear strength decreases significantly. It might be caused by the property change of adhesive from ductile to brittle. The acetone surface treatment produces the best bonding between the adhesive and adherends (CFRP and Al-plate 2024), and the highest shear strength is 9.31 MPa. The surface treatment give the humidification effect of adherend surfaces by adhesive. The failure characteristic shows that the mixed failure of light-fiber-tear-failure and cohesive-failure are occurred on the high shear strength of SLJ, and the low shear strength commonly has the adhesive-failure type.

  8. Estimating reef fish discard mortality using surface and bottom tagging: effects of hook injury and barotrauma

    USGS Publications Warehouse

    Rudershausen, Paul J.; Buckel, Jeffrey A.; Hightower, Joseph E.

    2013-01-01

    We estimated survival rates of discarded black sea bass (Centropristis striata) in various release conditions using tag–recapture data. Fish were captured with traps and hook and line from waters 29–34 m deep off coastal North Carolina, USA, marked with internal anchor tags, and observed for release condition. Fish tagged on the bottom using SCUBA served as a control group. Relative return rates for trap-caught fish released at the surface versus bottom provided an estimated survival rate of 0.87 (95% credible interval 0.67–1.18) for surface-released fish. Adjusted for results from the underwater tagging experiment, fish with evidence of external barotrauma had a median survival rate of 0.91 (0.69–1.26) compared with 0.36 (0.17–0.67) for fish with hook trauma and 0.16 (0.08–0.30) for floating or presumably dead fish. Applying these condition-specific estimates of survival to non-tagging fishery data, we estimated a discard survival rate of 0.81 (0.62–1.11) for 11 hook and line data sets from waters 20–35 m deep and 0.86 (0.67–1.17) for 10 trap data sets from waters 11–29 m deep. The tag-return approach using a control group with no fishery-associated trauma represents a method to accurately estimate absolute discard survival of physoclistous reef species.

  9. A prospective investigation of biomechanical risk factors for patellofemoral pain syndrome. The joint undertaking to monitor and prevent ACL injury (JUMP-ACL) cohort

    PubMed Central

    Boling, Michelle C.; Padua, Darin A; Marshall, Stephen W.; Guskiewicz, Kevin; Pyne, Scott; Beutler, Anthony

    2010-01-01

    Background Patellofemoral pain syndrome (PFPS) is one of the most common chronic knee injuries; however, little research has been done to determine the risk factors for this injury. Hypothesis Altered lower extremity kinematics and kinetics, decreased strength, and altered postural measurements will be risk factors. Study Design Prospective cohort. Methods 1597 participants were enrolled in this investigation and prospectively followed from the date of their enrollment (July 2005, July 2006, or July 2007) through January 2008. Each participant underwent baseline data collection during their pre-freshman summer at the United States Naval Academy. Baseline data collection included three-dimensional motion analysis during a jump-landing task, six lower extremity isometric strength tests, and postural alignment measurements (navicular drop and Q-angle). Participants were prospectively followed from their date of enrollment to January 2008 (maximum of 2.5 years of follow up). Results Risk factors for the development of PFPS included decreased knee flexion angle, decreased vertical ground reaction force, and increased hip internal rotation angle during the jump-landing task. Additionally, decreased quadriceps and hamstring strength, increased hip external rotator strength, and increased navicular drop were risk factors for the development of PFPS. Conclusions Multiple modifiable risk factors for PFPS pain have been identified in this investigation. In order to decrease the incidence of this chronic injury, the risk factors for PFPS need to be targeted in injury prevention programs. Clinical Relevance Prevention programs should focus on increasing strength of the lower extremity musculature along with instructing proper mechanics during dynamic movements in order to decrease the incidence of PFPS. PMID:19797162

  10. Cold injuries.

    PubMed

    Kruse, R J

    1995-01-01

    There are two categories of cold injury. The first is hypothermia, which is a systemic injury to cold, and the second is frostbite, which is a local injury. Throughout history, entire armies, from George Washington to the Germans on the Russian Front in World War II, have fallen prey to prolonged cold exposure. Cold injury is common and can occur in all seasons if ambient temperature is lower than the core body temperature. In the 1985 Boston Marathon, even though it was 76 degrees and sunny, there were 75 runners treated for hypothermia. In general, humans adapt poorly to cold exposure. Children are at particular risk because of their relatively greater surface area/body mass ratio, causing them to cool even more rapidly than adults. Because of this, the human's best defense against cold injury is to limit his/her exposure to cold and to dress appropriately. If cold injury has occurred and is mild, often simple passive rewarming such as dry blankets and a warm room are sufficient treatment.

  11. Distal Radioulnar Joint Instability

    PubMed Central

    Mirghasemi, Ali R.; Lee, Daniel J.; Rahimi, Narges; Rashidinia, Shervin

    2015-01-01

    Distal radioulnar joint (DRUJ) instability is a common clinical condition but a frequently missed diagnosis. Both surgical and nonsurgical treatments are possible for chronic cases of DRUJ instability. Nonsurgical treatment can be considered as the primary therapy in less active patients, while surgery should be considered to recover bone and ligament injuries if nonsurgical treatment fails to restore forearm stability and function. The appropriate choice of treatment depends on the individual patient and specific derangement of the DRUJ PMID:26328241

  12. Surface electromyography as a measure of trunk muscle activity in patients with spinal cord injury: a meta-analytic review

    PubMed Central

    Wang, Yi-ji; Zhou, Hong-jun; Liu, Geng-lin; Zheng, Ying; Wei, Bo; Zhang, Ying; Hao, Chun-xia; Kang, Hai-qiong; Yuan, Yuan; Gao, Lian-jun

    2016-01-01

    Context Surface electromyography (SEMG) may be a sensitive marker for distinguishing the activity of trunk muscles, which are critical to functional mobility recovery in patients with spinal cord injury (SCI). Objectives This manuscript presents a systematic review and meta-analysis of the published literature on the effect of SEMG as a measure of trunk muscle activity in patients with SCI. Methods A comprehensive search of the research literature included Pubmed, Medline, CNKI, WANFANG DATA, Web of Science, Elsevier, Wiley-Blackwell, Karger, OVID, and a review of reference lists within found articles. Case-control, cohort, and cross-sectional studies were included in the review. Results Eleven studies were included in this meta-analysis. Trunk muscle activities for the sitting condition were greater in patients with SCI than normal subjects. SEMG activity of trunk muscles for the sitting condition and posterior transfer was greater in patients with high level (HL)-SCI compared to those with low level (LL)-SCI. In addition, across studies, the level of trunk muscle activity for various difficulty settings was different for a given SCI group. Conclusion This systematic review evaluated the value of trunk muscles for patients with SCI. We recommend use of SEMG as an assessment tool for improving the comparability and interpretability of trunk muscle activity of SCI therapeutic strategies. PMID:26496045

  13. Wrist Instability After Injury

    PubMed Central

    Muminagic, Sahib; Kapidzic, Tarik

    2012-01-01

    Fractures of the bones that make the wrist joint together with injury to the ligaments and joint capsules are frequent traumas. It can cause besides limited movement also the pathological mobility. These mild injuries often do not provide the degree of recognizable symptoms and signs. They are diagnosed by X-ray imaging, stress images. Before arthrography was an important method, but nowadays arthroscopy has the advantage. Fresh bone and ligament injuries can be and should be repaired in the early posttraumatic period. Unrecognized and undiagnosed injuries are leading to instability of the wrist, to motion abnormalities or impingement overload syndrome. In the treatment of instability important place have reconstruction of the ligaments and arthrodesis of the wrist. PMID:23678318

  14. Joint pain

    MedlinePlus

    ... that may be done include: CBC or blood differential C-reactive protein Joint x-ray Sedimentation rate ... chap 256. Schaible H-G. Joint pain: basic mechanisms. In: McMahon SB, Koltzenburg M, Tracey I, Turk ...

  15. Bipolar clavicular injury.

    PubMed

    Pang, K P; Yung, S W; Lee, T S; Pang, C E

    2003-10-01

    While clavicular injuries are fairly common, bipolar clavicular injuries are not. They may involve dislocations at both ends of the clavicle, or a fracture at one end and a dislocation at the other. We present two cases; a patient with a bipolar clavicular dislocation, and another with a fracture in both medial and lateral ends of the clavicle with anterior dislocation of the sternoclavicular joint. Both were treated conservatively, with fairly good range of motion and return to normal activity.

  16. Joint Interdiction

    DTIC Science & Technology

    2016-09-09

    Purpose This publication has been prepared under the direction of the Chairman of the Joint Chiefs of Staff. It sets forth joint doctrine to govern the...governmental and nongovernmental organizations, multinational forces, and other interorganizational partners. It provides military guidance for the...exercise of authority by combatant commanders and other joint force commanders (JFCs), and prescribes joint doctrine for operations and training. It

  17. Kinematics of the human pelvis following open book injury.

    PubMed

    Hefzy, M S; Ebraheim, N; Mekhail, A; Caruntu, D; Lin, H; Yeasting, R

    2003-05-01

    The objective of this study is to determine the three dimensional kinematics of the human pelvis including both sacroiliac joints following a simulated open book injury induced on cadavers by applying anterior-posterior compressive loads to the pelvis. An electromagnetic digitizing and motion tracking system was utilized to measure the morphology of the pelvis and the relative movements of its bones during this simulated open book fracture. The screw displacement axis method was used to describe the relative motion between the sacrum and each hipbone. Morphologically, it was found that the articular surfaces forming the sacroiliac joints could be approximated with planar surfaces directed from proximal and lateral to distal and medial and from posteromedial to anterolateral. The kinematic data obtained from this study indicate that there is a direct correlation between the opening of the symphysis pubis and the opening of the sacroiliac joint (SIJ) during open book injury. This suggests that the extent of injury of the SIJ maybe estimated from the degree of opening of the symphysis pubis as demonstrated on anteroposterior (A-P) x-rays. The results obtained from this study also indicate that the motion of the hipbone with respect to the sacrum on the side of the sacroiliac joint opening is almost a pure rotation, which translates clinically on the A-P x-rays as pure opening of the SIJ without vertical displacement. The average axis of rotation was found to be almost parallel to the SIJ planar articular surface. Furthermore, the pubic bone on the side of SIJ opening was found to displace inferiorly and posteriorly. One can thus conclude that in open book pelvic injuries, the pubic bone on the side of injury displaces inferiorly on the outlet projection x-rays with no vertical displacement of the SIJ. This is important since the initial assessment of the open book injury in the emergency room includes outlet projection x-rays. From this study, the relative vertical

  18. Evaluation of a bisphosphonate enriched ultra-high molecular weight polyethylene for enhanced total joint replacement bearing surface functionality

    NASA Astrophysics Data System (ADS)

    Wright-Walker, Cassandra Jane

    Each year in the United States there is an increasing trend of patients receiving total joint replacement (TJR) procedures. Approximately a half million total knee replacements (TKRs) are performed annually in the United States with increasing prevalence attributed to baby-boomers, obesity, older, and younger patients. This trend is also seen for total hip replacements (THRs) as well. The use of ultra high molecular weight polyethylene (UHMWPE) inserts in TJRs results in wear particle-induced osteolysis, which is the predominant cause for prosthesis failure and revision surgery. Sub-micron size particle generation is inevitable despite the numerous efforts in improving this bearing material. Work by others has shown that the use of oral and intravenous systemic bisphosphonates (BP) can significantly minimize periprosthetic osteolysis. However, the systemic delivery and the high solubility of BPs results in a predominant portion of the drug being excreted via the kidney without reaching its target, bone. This doctoral research project is focused on the development and evaluation of a novel method to administer BPs locally using the inherent wear of UHMWPE for possible use as an anti-osteolysis treatment. For new materials to be considered, they must be mechanically and tribologically comparable to the current gold standard, UHMWPE. In order to evaluate this material, mechanical, drug elution and tribological experiments were performed to allow assessment of material properties. Tensile tests showed comparable yield stress and pin-on-disk testing showed comparable wear to standard virgin UHMWPE. Further, drug elution tests have shown that BP was released from the enriched material both in static and dynamic conditions. Additionally, an aggressive 2 million cycle total knee simulator experiment has shown statistically similar wear results for the two materials. Overall, this research has provided the groundwork for further characterization and development of a new

  19. Exercise following a short immobilization period is detrimental to tendon properties and joint mechanics in a rat rotator cuff injury model.

    PubMed

    Peltz, Cathryn D; Sarver, Joseph J; Dourte, Leann M; Würgler-Hauri, Carola C; Williams, Gerald R; Soslowsky, Louis J

    2010-07-01

    Rotator cuff tears are a common clinical problem that can result in pain and disability. Previous studies in a rat model showed enhanced tendon to bone healing with postoperative immobilization. The objective of this study was to determine the effect of postimmobilization activity level on insertion site properties and joint mechanics in a rat model. Our hypothesis was that exercise following a short period of immobilization will cause detrimental changes in insertion site properties compared to cage activity following the same period of immobilization, but that passive shoulder mechanics will not be affected. We detached and repaired the supraspinatus tendon of 22 Sprague-Dawley rats, and the injured shoulder was immobilized postoperatively for 2 weeks. Following immobilization, rats were prescribed cage activity or exercise for 12 weeks. Passive shoulder mechanics were determined, and following euthanasia, tendon cross-sectional area and mechanical properties were measured. Exercise following immobilization resulted in significant decreases compared to cage activity in range of motion, tendon stiffness, modulus, percent relaxation, and several parameters from both a structurally based elastic model and a quasi-linear viscoelastic model. Therefore, we conclude that after a short period of immobilization, increased activity is detrimental to both tendon mechanical properties and shoulder joint mechanics, presumably due to increased scar production.

  20. Surface NO2 fields derived from joint use of OMI and GOME-2A observations with EMEP model output

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Svendby, Tove; Stebel, Kerstin

    2016-04-01

    Nitrogen dioxide (NO2) is one of the most prominent air pollutants. Emitted primarily by transport and industry, NO2 has a major impact on health and economy. In contrast to the very sparse network of air quality monitoring stations, satellite data of NO2 is ubiquitous and allows for quantifying the NO2 levels worldwide. However, one drawback of satellite-derived NO2 products is that they provide solely an estimate of the entire tropospheric column, whereas what is generally needed for air quality applications are the concentrations of NO2 near the surface. Here we derive surface NO2 concentration fields from OMI and GOME-2A tropospheric column products using the EMEP chemical transport model as auxiliary information. The model is used for providing information of the boundary layer contribution to the total tropospheric column. For preparation of deriving the surface product, a comprehensive model-based analysis of the spatial and temporal patterns of the NO2 surface-to-column ratio in Europe was carried out for the year 2011. The results from this analysis indicate that the spatial patterns of the surface-to-column ratio vary only slightly. While the highest ratio values can be found in some shipping lanes, the spatial variability of the ratio in some of the most polluted areas of Europe is not very high. Some but not all urban agglomeration shows high ratio values. Focusing on the temporal behavior, the analysis showed that the European-wide average ratio varies throughout the year. The surface-to-column ratio increases from January all the way through April when it reaches its maximum, then decreases relatively rapidly to average levels and then stays mostly constant throughout the summer. The minimum ratio is observed in December. The knowledge gained from analyzing the spatial and temporal patterns of the surface-to-column ratio was then used to produce surface NO2 products from the daily NO2 data for OMI and GOME-2A. This was carried out using two methods

  1. Clad metal joint closure

    SciTech Connect

    Siebert, O.W.

    1985-04-09

    A plasma arc spray overlay of cladding metals is used over joints between clad metal pieces to provide a continuous cladding metal surface. The technique permits applying an overlay of a high melting point cladding metal to a cladding metal surface without excessive heating of the backing metal.

  2. Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG.

    PubMed

    Uzun, S; Pourmoghaddam, A; Hieronymus, M; Thrasher, T A

    2012-11-01

    Wheelchair basketball is the most popular exercise activity among individuals with spinal cord injury (SCI). The purpose of this study was to investigate muscular endurance and fatigue in wheelchair basketball athletes with SCI using surface electromyography (SEMG) and maximal torque values. SEMG characteristics of 10 wheelchair basketball players (WBP) were compared to 13 able-bodied basketball players and 12 sedentary able-bodied subjects. Participants performed sustained isometric elbow flexion at 50% maximal voluntary contraction until exhaustion. Elbow flexion torque and SEMG signals were recorded from three elbow flexor muscles: biceps brachii longus, biceps brachii brevis and brachioradialis. SEMG signals were clustered into 0.5-s epochs with 50% overlap. Root mean square (RMS) and median frequency (MDF) of SEMG signals were calculated for each muscle and epoch as traditional fatigue monitoring. Recurrence quantification analysis was used to extract the percentage of determinism (%DET) of SEMG signals. The slope of the %DET for basketball players and WBP showed slower increase with time than the sedentary able-bodied control group for three different elbow flexor muscles, while no difference was observed for the slope of the %DET between basketball and WBP. This result indicated that the athletes are less fatigable during the task effort than the nonathletes. Normalized MDF slope decay exhibited similar results between the groups as %DET, while the slope of the normalized RMS failed to show any significant differences among the groups (p > 0.05). MDF and %DET could be useful for the evaluation of muscle fatigue in wheelchair basketball training. No conclusions about special training for WBP could be determined.

  3. Baseball injuries to the hand.

    PubMed

    Dawson, W J; Pullos, N

    1981-06-01

    We conducted an epidemiological and etiological study of softball injuries to the hand in order to inform emergency medicine personnel of the high frequency and causative factors of these injuries. Injuries to the hand and fingers from baseball and softball comprised 2.2% of emergency department visits during this study. Most frequent injuries were: 1) sprain and sprain-fracture of the proximal IP joint (31.6%); and 2) the so-called "mallet" or "baseball finger" injury to the distal joint (18.9%). The 16-inch softball was the cause of more than two-thirds of all these injuries, most of which occurred in patients between the ages of 11 and 30. Treatment recommendations are beyond the scope of this article.

  4. Anticipatory changes in control of swing foot and lower limb joints when walking onto a moving surface traveling at constant speed.

    PubMed

    Hsu, Wei-Chun; Wang, Ting-Ming; Lu, Hsuan-Lun; Lu, Tung-Wu

    2015-01-01

    Adapting to a predictable moving surface such as an escalator is a crucial part of daily locomotor tasks in modern cities. However, the associated biomechanics have remained unexplored. In a gait laboratory, fifteen young adults walked from the ground onto a moving or a static surface while their kinematic and kinetic data were obtained for calculating foot and pelvis motions, as well as the angles and moments of the lower limb joints. Between-surface-condition comparisons were performed using a paired t-test (α = 0.05). The results showed that anticipatory locomotor adjustments occurred at least a stride before successfully walking onto the moving surface, including increasing step length and speed in the trailing step (p < 0.05), but the opposite in the leading step (p < 0.05). These modifications reduced the plantarflexor moment of the trailing ankle needed for stabilizing the body, while placing increased demand on the knee extensors of the trailing stance limb. For a smooth landing and to reduce the risk of instability, the subjects adopted a flat foot contact pattern with reduced leading toe-clearance (p < 0.05) at an instantaneous speed matching that of the moving surface (p > 0.05), mainly through reduced extension of the trailing hip but increased pelvic anterior tilt and leading swing ankle plantarflexion (p < 0.05). The current results provide baseline data for future studies on other populations, which will contribute to the design and development of strategies to address falls while transferring onto moving surfaces such as escalators.

  5. Joint inversion of multi-configuration electromagnetic induction measurements to estimate soil wetting patterns during surface drip irrigation

    NASA Astrophysics Data System (ADS)

    Jadoon, Khan Z.; Moghadas, Davood; Jadoon, Aurangzeb; Missimer, Thomas M.; McCabe, Matthew

    2014-05-01

    In arid and semi-arid regions, development of precise information on the soil wetting pattern is important to optimize drip irrigation system design for sustainable agricultural water management. Usually mathematical models are commonly used to describe infiltration from a point source to design and manage drip irrigation systems. The extent to which water migrates laterally and vertically away from the drip emitter depends on many factors, including dripper discharge rate, the frequency of water application, duration of drip emission, the soil hydraulic characteristics, initial conditions, evaporation, root water uptake and root distribution patterns. However, several simplified assumptions in the mathematical models affect their utility to provide useful design information. In this respect, non-invasive geophysical methods, i.e., low frequency electromagnetic induction (EMI) systems are becoming powerful tools to map spatial and temporal soil moisture patterns due to fast measurement capability and sensitivity to soil water content and salinity. In this research, a new electromagnetic system, the CMD mini-Explorer, is used for soil characterization to measure the wetting patterns of drip irrigation systems using joint inversion of multi-configuration EMI measurements. Six transects of EMI measurements were carried out in a farm where Acacia trees are irrigated with brackish water using a drip irrigation system. EMI reference data (ground-truths) were calculated using vertical soil electrical conductivity recorded in different trenches along one of the measurement transects. Reference data is used for calibration to minimize the instrumental shifts which often occur in EMI data. Global and local optimization algorithms are used sequentially, to minimize the misfit between the measured and modeled apparent electrical conductivity (δa) to reconstruct the vertical electrical conductivity profile. The electromagnetic forward model based on full solution of Maxwell

  6. Earth Surface Deformation in the North China Plain Detected by Joint Analysis of GRACE and GPS Data

    PubMed Central

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C.K.; Li, Zhao

    2014-01-01

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1–4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1–2 mm/year and a correlation of 85.0%–98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements. PMID:25340454

  7. Earth surface deformation in the North China Plain detected by joint analysis of GRACE and GPS data.

    PubMed

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C K; Li, Zhao

    2014-10-22

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1-4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1-2 mm/year and a correlation of 85.0%-98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements.

  8. Turco's injury: diagnosis and treatment.

    PubMed

    da Silva, Ana Paula Simões; Shimba, Leandro Girardi; Ribas, Luiz Henrique Boraschi Vieira; de Almeida, Alexandre Simmonds; Naves, Vinicius; Duarte Júnior, Aires

    2014-01-01

    The aim of this study was to alert doctors to the existence of Turco's injury and discus the existing treatments that have been described in the worldwide literature. A bibliographic survey of Lisfranc's injury and Turco's injury covering from 1985 to 2013 was conducted in the SciELO and PubMed databases. Among the 193 articles, those relating to bone-ligament injuries of the Lisfranc joint and high-energy trauma were excluded, as were the case reports. The patients selected were professional or amateur athletes who solely presented a ligament injury to the Lisfranc joint (Turco's injury), which was diagnosed from the history, physical examination, radiographs and magnetic resonance images. Non-athletic patients and those with associated bone injuries were excluded (10). According to the injury classification, the patients were treated by means of either an open or a closed procedure and then a standard rehabilitation protocol. Out of the 10 patients, five underwent conservative treatment and five underwent surgical treatment using different techniques and synthesis materials. We obtained two poor results, one satisfactory, five good and two excellent. We conclude that the correct diagnosis has a direct influence on the treatment and on the final result obtained, and that lack of knowledge of this injury is the main factor responsible for underdiagnosing Turco's injury. There is a need for randomized prospective studies comparing the types of synthesis and evolution of treated cases, in order to define the best treatment for this injury.

  9. Hypermobility and Knee Injuries.

    ERIC Educational Resources Information Center

    Steiner, Mark E.

    1987-01-01

    A review of research on the effect of hypermobility on knee injury indicates that greater than normal joint flexibility may be necessary for some athletic endeavors and that it may be possible to change one's underlying flexibility through training. However, for most athletes, inherited flexibility probably plays only a small role, if any, in…

  10. Brief report: reconstruction of joint hyaline cartilage by autologous progenitor cells derived from ear elastic cartilage.

    PubMed

    Mizuno, Mitsuru; Kobayashi, Shinji; Takebe, Takanori; Kan, Hiroomi; Yabuki, Yuichiro; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Nakabayashi, Seiichiro; Ik, Lee Jeong; Maegawa, Jiro; Taniguchi, Hideki

    2014-03-01

    In healthy joints, hyaline cartilage covering the joint surfaces of bones provides cushioning due to its unique mechanical properties. However, because of its limited regenerative capacity, age- and sports-related injuries to this tissue may lead to degenerative arthropathies, prompting researchers to investigate a variety of cell sources. We recently succeeded in isolating human cartilage progenitor cells from ear elastic cartilage. Human cartilage progenitor cells have high chondrogenic and proliferative potential to form elastic cartilage with long-term tissue maintenance. However, it is unknown whether ear-derived cartilage progenitor cells can be used to reconstruct hyaline cartilage, which has different mechanical and histological properties from elastic cartilage. In our efforts to develop foundational technologies for joint hyaline cartilage repair and reconstruction, we conducted this study to obtain an answer to this question. We created an experimental canine model of knee joint cartilage damage, transplanted ear-derived autologous cartilage progenitor cells. The reconstructed cartilage was rich in proteoglycans and showed unique histological characteristics similar to joint hyaline cartilage. In addition, mechanical properties of the reconstructed tissues were higher than those of ear cartilage and equal to those of joint hyaline cartilage. This study suggested that joint hyaline cartilage was reconstructed from ear-derived cartilage progenitor cells. It also demonstrated that ear-derived cartilage progenitor cells, which can be harvested by a minimally invasive method, would be useful for reconstructing joint hyaline cartilage in patients with degenerative arthropathies.

  11. The Rationale for Joint Mobilization.

    ERIC Educational Resources Information Center

    Burkhardt, Sandy

    This paper presents an overview of the functions of connective tissue and the mechanisms of joint injury and contracture formation in relation to therapeutic exercise. The components of connective tissue operation are explained, including fibroblasts, macrophages, plasma cells, and collagen. An examination of the histology of connective tissue as…

  12. MUSCLE INJURIES IN ATHLETES

    PubMed Central

    Barroso, Guilherme Campos; Thiele, Edilson Schwansee

    2015-01-01

    This article had the aim of demonstrating the physiology, diagnosis and treatment of muscle injuries, focusing on athletes and their demands and expectations. Muscle injuries are among the most common complaints in orthopedic practice, occurring both among athletes and among non-athletes. These injuries present a challenge for specialists, due to the slow recovery, during which time athletes are unable to take part in training and competitions, and due to frequent sequelae and recurrences of the injuries. Most muscle injuries (between 10% and 55% of all injuries) occur during sports activities. The muscles most commonly affected are the ischiotibial, quadriceps and gastrocnemius. These muscles go across two joints and are more subject to acceleration and deceleration forces. The treatment for muscle injuries varies from conservative treatment to surgery. New procedures are being used, like the hyperbaric chamber and the use of growth factors. However, there is still a high rate of injury recurrence. Muscle injury continues to be a topic of much controversy. New treatments are being researched and developed, but prevention through muscle strengthening, stretching exercises and muscle balance continues to be the best “treatment”. PMID:27027021

  13. MUSCLE INJURIES IN ATHLETES.

    PubMed

    Barroso, Guilherme Campos; Thiele, Edilson Schwansee

    2011-01-01

    This article had the aim of demonstrating the physiology, diagnosis and treatment of muscle injuries, focusing on athletes and their demands and expectations. Muscle injuries are among the most common complaints in orthopedic practice, occurring both among athletes and among non-athletes. These injuries present a challenge for specialists, due to the slow recovery, during which time athletes are unable to take part in training and competitions, and due to frequent sequelae and recurrences of the injuries. Most muscle injuries (between 10% and 55% of all injuries) occur during sports activities. The muscles most commonly affected are the ischiotibial, quadriceps and gastrocnemius. These muscles go across two joints and are more subject to acceleration and deceleration forces. The treatment for muscle injuries varies from conservative treatment to surgery. New procedures are being used, like the hyperbaric chamber and the use of growth factors. However, there is still a high rate of injury recurrence. Muscle injury continues to be a topic of much controversy. New treatments are being researched and developed, but prevention through muscle strengthening, stretching exercises and muscle balance continues to be the best "treatment".

  14. The joint effect of surface microtopography and near-surface structure on microcontact conditions: (Quarterly progress report, November--December 1988 and January 1989)

    SciTech Connect

    McCool, J.I.

    1989-01-01

    Pin-on-disk tests are now complete on 18 of the 27 ceramic Phase I specimens. A total of 45 hardened M50 high alloy steel disks have been fabricated. Three distinct surface finishes, having nominal values of 1, 3, and 10 microinch rms, have been applied to sets of 15 of these specimens. Numerical results taken from a study found in the literature on the analytical determination of the deformation of layered half spaces by an axisymmetric rigid indentor have been recast in the form of correction factors wherewith a microcontact analysis of coated rough surfaces can be performed using simulation. 2 refs., 3 figs.

  15. Back Injuries

    MedlinePlus

    ... extending from your neck to your pelvis. Back injuries can result from sports injuries, work around the house or in the garden, ... back is the most common site of back injuries and back pain. Common back injuries include Sprains ...

  16. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  17. Nonunion of distal radius fracture and distal radioulnar joint injury: a modified Sauvé-Kapandji procedure with a cubitus proradius transposition as autograft.

    PubMed

    Villamor, Angel; Rios-Luna, Antonio; Villanueva-Martínez, Manuel; Fahandezh-Saddi, Homid

    2008-12-01

    The Sauvé-Kapandji (SK) procedure is indicated in distal radius nonunion or malunion and distal radioulnar joint (DRUJ) instability. It can also be used to treat the rheumatoid wrist with severe degenerative changes in the DRUJ. The main objective is to allow a pain-free range of movement. We present a patient with rheumatoid arthritis and distal radius nonunion who, after three operations, was treated with the SK procedure. The clinical and radiological results were excellent. A 53-year-old woman diagnosed with rheumatoid arthritis fell on her forearm at home 2 years ago. Examination at an outpatient clinic revealed a distal radius fracture classified as type V according to the Frykman classification. She had been operated three times with open reduction internal fixation using a plate, screws, and bone allograft. She came to our institution with a distal radius nonunion, positive post-traumatic ulnar variance, and ulnar nerve paresis. The range of movements was 20 degrees -10 degrees flexion-extension and 40 degrees -30 degrees pronation-supination, and she needed daily fentanyl. We performed a modified SK procedure with an autologous iliac crest bone graft and ulnar bone graft from the osteotomy area (cubitus proradius), bone morphogenetic protein, and a low profile distal radius plate. After 1 year of follow-up, the distal radius fracture has healed and the wrist is pain-free with a complete range of movement in flexion-extension and pronation-supination. The main indication for the SK procedure is post-traumatic positive ulnar variance and associated ulnocarpal impaction. The cubitus proradius bone graft transposition is an interesting technical note that makes this case a challenge for skilled orthopedic hand surgeons.

  18. Shoulder acromioclavicular joint reconstruction options and outcomes.

    PubMed

    Lee, Simon; Bedi, Asheesh

    2016-12-01

    Acromioclavicular joint separations are a common cause of shoulder pain in the young athletic population. In high-grade injuries, acromioclavicular joint reconstruction procedures may be indicated for functional improvement. There is currently no gold standard for the surgical management of these injuries. Multiple reconstructive options exist, including coracoclavicular screws, hook plates, endobutton coracoclavicular fixations, and anatomic ligament reconstructions with tendon grafts. This article aims to review pertinent acromioclavicular joint anatomy and biomechanics, radiographic evaluation, classification system, as well as reconstruction options, outcomes, and complications.

  19. Examination of Surface Residuals Obtained During Re-Lubrication of the International Space Station (ISS) Solar Alpha Rotary Joint (SARJ)

    NASA Technical Reports Server (NTRS)

    Martinez, J. E.; Golden, J. L.

    2012-01-01

    The starboard SARJ mechanism on the ISS suffered a premature lubrication failure, resulting in widespread loss of the nitride case layer on its 10.3 meter circumference, 15-5PH steel race ring [1, 2]. To restore functionality, vacuum-stable grease was applied on-orbit, first to the port SARJ mechanism to save it from the damage suffered by the starboard mechanism. After 3 years of greased operation, telemetry indicated that the port mechanism required relubrication, so part of that process included sampling each of the three race ring surfaces to evaluate any wear debris recovered and the state of the originally applied grease. Extensive microscopic examination was conducted, which directed subsequent microanalysis of particulate. Since the SARJ mechanism operates in the vacuum of space, a sampling method and tool had to be developed for use by astronauts while working in the extravehicular mobility unit (EMU). The sampling tool developed was a cotton terry-cloth mitt for the EMU glove, with samples taken by swiping each of the three port SARJ race-ring surfaces. The sample mitts for each surface were folded inward after sampling to preserve sample integrity, for return and ground analysis. The sample mitt for what is termed the outer canted surface of the SARJ race-ring is shown in Figure 1. Figure 1 also demonstrates how increasing levels of magnification were used to survey the contamination removed in sampling, specifically looking for signs of wear debris or other features which could be further evaluated using Scanning Electron Microscopy (SEM) methods. The most surprising overall result at this point in the analysis was the relatively small amounts of grease recovered during sampling. It is clear that the mechanism was not operating with surplus lubricant. Obviously, evidence of molybdenum disulfide (MoS2), a major component in the grease applied, was prevalent in the analysis conducted. But a small amount of mechanism wear debris was observed. Figure 2

  20. Modelling of the mechanical behavior of a polyurethane finger interphalangeal joint endoprosthesis after surface modification by ion implantation

    NASA Astrophysics Data System (ADS)

    Beliaev, A.; Svistkov, A.; Iziumov, R.; Osorgina, I.; Kondyurin, A.; Bilek, M.; McKenzie, D.

    2016-04-01

    Production of biocompatible implants made of polyurethane treated with plasma is very perspective. During plasma treatment the surface of polyurethane acquires unique physic-chemical properties. However such treatment may change the mechanical properties of polyurethane which may adversely affect the deformation behaviour of the real implant. Therefore careful study of the mechanical properties of the plasma-modified polyurethane is needed. In this paper, experimental observations of the elastic characteristics of plasma treated polyurethane and modelling of the deformation behaviour of polyurethane bio-implants are reported.

  1. Fabrication of dense α-alumina layer on Ti-6Al-4V alloy hybrid for bearing surfaces of artificial hip joint.

    PubMed

    Khanna, Rohit; Kokubo, Tadashi; Matsushita, Tomiharu; Takadama, Hiroaki

    2016-12-01

    Recent advances in hip replacements are focused towards producing reliable bearing surfaces to enhance their longevity. In this perspective, progressive attempts have been made to improve the wear resistance of polyethylene to eliminate osteolysis and mechanical reliability of brittle alumina ceramics, but in vain. It is proposed that both high wear resistance and mechanical reliability can be retained if a thin layer of dense alumina is formed onto high toughness Ti-6Al-4V alloy. For this purpose, we devised a unique methodology in which a layer of Al metal was deposited onto the Ti alloy substrate by cold spraying (CS), followed by a heat treatment to form Al3Ti reaction layer at their interface to improve adhesion and subsequent micro-arc oxidation (MAO) treatment to transform Al to alumina layer. An optimal MAO treatment of cold sprayed Al formed an adherent and dense α-alumina layer with high Vickers hardness matching with that of sintered alumina used as a femoral head. Structure-phase-property relationships in dense α-alumina layer have been revealed and discussed in the light of our research findings. The designed alumina/Ti alloy hybrid might be a potential candidate for reliable bearing surfaces of artificial hip joint.

  2. Surface marker cluster translation, rotation, scaling and deformation: Their contribution to soft tissue artefact and impact on knee joint kinematics.

    PubMed

    Benoit, D L; Damsgaard, M; Andersen, M S

    2015-07-16

    When recording human movement with stereophotogrammetry, skin deformation and displacement (soft tissue artefact; STA) inhibits surface markers' ability to validly represent the movement of the underlying bone. To resolve this issue, the components of marker motions which contribute to STA must be understood. The purpose of this study is to describe and quantify which components of this marker motion (cluster translation, rotation, scaling and deformation) contribute to STA during the stance phase of walking, a cutting manoeuvre, and one-legged hops. In vivo bone pin-based tibio-femoral kinematics of six healthy subjects were used to study skin marker-based STA. To quantify how total cluster translation, rotation, scaling and deformation contribute to STA, a resizable and deformable cluster model was constructed. STA was found to be greater in the thigh than the shank during all three movements. We found that the non-rigid (i.e. scaling and deformation) movements contribute very little to the overall amount of error, rendering surface marker optimisation methods aimed at minimising this component superfluous. The results of the current study indicate that procedures designed to account for cluster translation and rotation during human movement are required to correctly represent the motion of body segments, however reducing marker cluster scaling and deformation will have little effect on STA.

  3. Crustal Velocity Structure beneath Wonju, Korea Using the H-? Stacking Method and Joint Inversion of Receiver Functions and Surface-wave Dispersion Curves

    NASA Astrophysics Data System (ADS)

    Jeon, T.; Park, Y.; Kang, I.; Kim, K. Y.

    2013-12-01

    To estimate the crustal and upper mantle velocity structure beneath Wonju in the central part of the Korean peninsula, we applied the H-κ stacking method and a joint inversion of the receiver functions and surface-wave dispersion curves using 1,860 teleseismic events (Mw ≥5.5) observed between October 2002 and November 2009 on a Korea Seismic Research Station (KSRS) broadband station, KS31. KSRS is a primary station of the Comprehensive Nuclear-Test-Ban Treaty Organization designated as PS31. Both methods were applied for eight ranges of back-azimuths to estimate crustal VP/VS ratios and Moho depths. In the H-κ stacking method, we determined that the average depth to a nearly flat Moho is 32.4 × 0.5 km within a 7.6 to 16.5 km radius of the seismic station with an estimated average ratio of P- to S-wave velocities of 1.72 × 0.04. Assuming VP of the average crustal P wave equal to 6.3 km/s gave reliable results. In the joint inversion, we estimated the Moho depth is 32 km in average of eight groups and Low Velocity Layer is between 6 and 12 km. A negative phase in the receiver functions at 1 s indicates the presence of a shear-wave low velocity layer in a depth interval of 10 to 18 km in the upper crust beneath the KS31 station. Fig. 1. Plot of inversion results of each group. Average of results represent a Moho discontinuity at 32 km and LVL between 6 and 12 km.

  4. Mechanobiological simulations of prenatal joint morphogenesis.

    PubMed

    Giorgi, Mario; Carriero, Alessandra; Shefelbine, Sandra J; Nowlan, Niamh C

    2014-03-21

    Joint morphogenesis is the process in which prenatal joints acquire their reciprocal and interlocking shapes. Despite the clinical importance of the process, it remains unclear how joints acquire their shapes. In this study, we simulate 3D mechanobiological joint morphogenesis for which the effects of a range of movements (or lack of movement) and different initial joint shapes are explored. We propose that static hydrostatic compression inhibits cartilage growth while dynamic hydrostatic compression promotes cartilage growth. Both pre-cavitational (no muscle contractions) and post-cavitational (with muscle contractions) phases of joint development were simulated. Our results showed that for hinge type motion (planar motion from 45° to 120°) the proximal joint surface developed a convex profile in the posterior region and the distal joint surface developed a slightly concave profile. When 3D movements from 40° to -40° in two planes were applied, simulating a rotational movement, the proximal joint surface developed a concave profile whereas the distal joint surface rudiment acquire a rounded convex profile, showing an interlocking shape typical of a ball and socket joint. The significance of this research is that it provides new and important insights into normal and abnormal joint development, and contributes to our understanding of the mechanical factors driving very early joint morphogenesis. An enhanced understanding of how prenatal joints form is critical for developing strategies for early diagnosis and preventative treatments for congenital musculoskeletal abnormalities such as developmental dysplasia of the hip.

  5. Joint detection of anatomical points on surface meshes and color images for visual registration of 3D dental models

    NASA Astrophysics Data System (ADS)

    Destrez, Raphaël.; Albouy-Kissi, Benjamin; Treuillet, Sylvie; Lucas, Yves

    2015-04-01

    Computer aided planning for orthodontic treatment requires knowing occlusion of separately scanned dental casts. A visual guided registration is conducted starting by extracting corresponding features in both photographs and 3D scans. To achieve this, dental neck and occlusion surface are firstly extracted by image segmentation and 3D curvature analysis. Then, an iterative registration process is conducted during which feature positions are refined, guided by previously found anatomic edges. The occlusal edge image detection is improved by an original algorithm which follows Canny's poorly detected edges using a priori knowledge of tooth shapes. Finally, the influence of feature extraction and position optimization is evaluated in terms of the quality of the induced registration. Best combination of feature detection and optimization leads to a positioning average error of 1.10 mm and 2.03°.

  6. The joint effect of surface microtopography and near-surface structure on microcontact conditions: Quarterly progress report for period 31 March 1987 to 30 June 1987

    SciTech Connect

    McCool, J.I.

    1987-06-01

    Key issues raised at a program review meeting are discussed and consequent revisions in approach are described. The calculation of expected contact size is considered and shown to be relatively insensitive to the separation of the contacting surfaces. It is shown that a microcontact analysis in which various asperity types are present in specified proportions may be carried out simply by using the mean modified Young's modulus in lieu of the value applicable for the case of single asperity types. The analysis presupposes that the microgeometry is not a function of asperity types.

  7. [Bilateral Asymmetric Traumatic Dislocation of Hip Joints].

    PubMed

    Paša, L; Veselý, R; Kelbl, M

    2017-01-01

    The authors present a rare case of bilateral asymmetric traumatic dislocation of hip joints, where the left joint was treated conservatively after the reduction, while the right joint, with an acetabular fragment interposition, was treated surgically - by arthroscopically assisted reduction and fixation of an osteochondral fragment of posterior wall of the acetabulum. The female patient healed with no complications, showing an excellent clinical outcome with no signs of instability or limited mobility of hip joints, and also with no signs of para-articular calcification or necrosis of the hip at 1 year after the injury and treatment. Bilateral asymmetric dislocation of hip joint is a rare injury with the total incidence of 150 cases as reported by the literature. Recently, its incidence is higher due to the increased traffic and the associated accident rate. A precise and prompt reduction of the injured hip joint is always necessary, if possible under general anesthesia. Also, it is always necessary to carry out a complete examination of the patient since this type of injury is always caused by a strong force and is often accompanied by injuries of other parts of the body. Key words: bilateral asymmetric dislocation of hip joints, hip arthroscopy, acetabular fracture.

  8. The wear of ultra-high molecular weight polyethylene sliding on metallic and ceramic counterfaces representative of current femoral surfaces in joint replacement.

    PubMed

    Lancaster, J G; Dowson, D; Isaac, G H; Fisher, J

    1997-01-01

    A number of studies have investigated the influence of surface roughness on the wear of ultra-high molecular weight polyethylene (UHMWPE) in total joint replacement. The results of these studies have shown that the wear factor is proportional to the counterface roughness raised to a power greater than one. In this laboratory study, the effect of surface finish of several biomaterials on the wear of UHMWPE was studied. The study was conducted using reciprocating pin-on-plate wear tests with bovine serum as a lubricant. The biomaterials investigated as the counterface material included stainless steel, cast cobalt chrome (CoCr), CoCr (ASTM F799), alumina ceramic and zirconia ceramic. The counterface topographies of the wear plates were produced using techniques representative of current manufacturing methods. The surface roughness of the wear plates was varied in the range Ra = 0.005-0.04 micron; this was representative of femoral heads and femoral knee components currently used clinically. Metals and ceramics with a similar surface roughness produced a similar wear rate of UHMWPE. For the limited range of smooth counterfaces used in this study only a moderate correlation was found between the surface roughness and the wear factors. For a change in counterface roughness Ra of 0.005 to 0.04 micron, the wear factor increased from 7.4 +/- 1.6 to 16.5 +/- 2.4 x 10(-9) mm3/N m (mean +/- standard error). This variation in counterface roughness had much less effect in wear than previously reported for rougher counterfaces. For an extended range of counterface roughness, a stronger correlation was found using an exponential function for the regression fit. The exponential function shows the benefits of decreased wear with decreased surface roughness. Although the wear rate decreased less rapidly with decreased counterface roughness for Ra values below 0.05 micron, there were significant advantages to be gained from improved femoral head roughness to below 0.01 micron Ra.

  9. The joint effect of surface microtopography and near-surface structure on microcontact conditions: Progress report for period September--November 1988

    SciTech Connect

    McCool, J.I.

    1988-11-01

    Surface documentation work has been completed on 1/3 of the 27 ceramic specimens that will be tested under this program. Indentation tests have been completed on another nine specimens. The indentation test results were examined critically and the constant in Auerbach's formula was deduced separately for each specimen. A tendency for this constant to be smaller for the polished specimens is noted. A preliminary appraisal is made of the relation between the measured wear values from the 9 pin-on-disk tests that have been completed to date and the predicted mean real contact area of a different but comparable set of specimens. The lowest measured wear was found to be associated with the lowest computed mean real contact pressure, but no more extensive trend could be discerned. Specimens have been obtained for Phase II testing and surface treatments and finishes have been tentatively selected. Microcontact model modifications needed for interpretation of Phase II tests are discussed. 2 refs., 2 figs., 1 tab.

  10. Posttraumatic Temporomandibular Joint Disorders

    PubMed Central

    Giannakopoulos, Helen E.; Quinn, Peter D.; Granquist, Eric; Chou, Joli C.

    2009-01-01

    The temporomandibular joint (TMJ) has many essential functions. None of its components are exempt from injury. Facial asymmetry, malocclusion, disturbances in growth, osteoarthritis, and ankylosis can manifest as complications from trauma to the TMJ. The goals of initial treatment include achievement of pretraumatic function, restoration of facial symmetry, and resolution of pain. These same objectives hold true for late repairs and reconstruction of the TMJ apparatus. Treatment is demanding, and with opposing approaches. The following article explores various treatment options for problems presenting as a result of a history of trauma to the TMJ. PMID:22110802

  11. Formation of tough composite joints

    SciTech Connect

    Brun, M.K.

    1997-05-01

    Joints which exhibit tough fracture behavior were formed in a composite with a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. In composites with BN coatings fibers were aligned uniaxially, while composites with Si{sub 3}N{sub 4}-coated fibers had a 0/90{degree} architecture. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure have been proposed. Joints with a simple overlap geometry (only a few fingers) would have to be very long in order to prevent brittle failure. Typical failure in these joints is caused by a crack propagating along the interfaces between the joint fingers. Joints of the same overall length, but with geometry changed to be symmetric about the joint centerline and with an extra shear surface exhibited tough fractures accompanied with extensive fiber pullout. The initial matrix cracking of these joints was relatively low because cracks propagated easily through the ends of the fingers. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength from 9 to 25 MPa, by changing the fiber coating, increased matrix cracking and ultimate strength of the composite significantly. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints will permit building of structures containing joints with only a minor reduction of design stresses.

  12. Delayed Administration of Pyroglutamate Helix B Surface Peptide (pHBSP), a Novel Nonerythropoietic Analog of Erythropoietin, Attenuates Acute Kidney Injury

    PubMed Central

    Patel, Nimesh S A; Kerr-Peterson, Hannah L; Brines, Michael; Collino, Massimo; Rogazzo, Mara; Fantozzi, Roberto; Wood, Elizabeth G; Johnson, Florence L; Yaqoob, Muhammad M; Cerami, Anthony; Thiemermann, Christoph

    2012-01-01

    In preclinical studies, erythropoietin (EPO) reduces ischemia-reperfusion–associated tissue injury (for example, stroke, myocardial infarction, acute kidney injury, hemorrhagic shock and liver ischemia). It has been proposed that the erythropoietic effects of EPO are mediated by the classic EPO receptor homodimer, whereas the tissue-protective effects are mediated by a hetero-complex between the EPO receptor monomer and the β-common receptor (termed “tissue-protective receptor”). Here, we investigate the effects of a novel, selective-ligand of the tissue-protective receptor (pyroglutamate helix B surface peptide [pHBSP]) in a rodent model of acute kidney injury/dysfunction. Administration of pHBSP (10 μg/kg intraperitoneally [i.p.] 6 h into reperfusion) or EPO (1,000 IU/kg i.p. 4 h into reperfusion) to rats subjected to 30 min ischemia and 48 h reperfusion resulted in significant attenuation of renal and tubular dysfunction. Both pHBSP and EPO enhanced the phosphorylation of Akt (activation) and glycogen synthase kinase 3β (inhibition) in the rat kidney after ischemia-reperfusion, resulting in prevention of the activation of nuclear factor-κB (reduction in nuclear translocation of p65). Interestingly, the phosphorylation of endothelial nitric oxide synthase was enhanced by EPO and, to a much lesser extent, by pHBSP, suggesting that the signaling pathways activated by EPO and pHBSP may not be identical. PMID:22415011

  13. Hand injury patterns in softball players using a 16 inch ball.

    PubMed

    Degroot, H; Mass, D P

    1988-01-01

    Softball is a popular recreational and competitive sport among both men and women. The injury rate in softball players is as high as that in baseball and basketball players. We conducted a retrospective analysis of 119 hand injuries in 108 patients treated at the University of Chicago hand clinic. All of the injuries were caused by the impact of a 16 inch circumference softball. Of the 119 injuries, 87 (73%) had bone involvement. Operative treatment was required in 26 (22%) injuries, 23 involving fractures and 3 involving soft tissue only. There was one (3.8%) operative complication. Of all injuries, 101 (86%) involved the finger joints, including 46 (39%) injuries to the distal interphalangeal (DIP) joint, 48 (40%) to the proximal interphalangeal (PIP) joint, and 7 (6%) to the metacarpophalangeal (MCP) joint. The most common DIP joint injury was a mallet injury. This fracture, the most common single type of injury in our series, accounted for 27% of all injuries. Of all mallet injuries, 86% were fractures. The most common PIP joint injury was a volar plate fracture, the second most common injury in our series. Variables such as the patient's sex, dominance or nondominance of hands, and early or late season play were not associated with a higher risk of injury. Certain parts of the hand, such as the more ulnar digits and the DIP and PIP joints, were at particularly high risk of injury.

  14. The joint effect of surface microtopography and near-surface structure on microcontact conditions: Progress report for period June--August 1988

    SciTech Connect

    McCool, J.I.; Bunting, B.G.

    1988-11-01

    A data base of roughness measurements has been compiled for the ceramic test specimens to be wear tested in this program. The computation of the equivalent isotropic RMS profile slope is discussed and numerical values are given. Wear tests performed on AlO, SiN, and SiC at ORNL show significant differences in wear coefficient due to both material and finish. Acoustic emission readings reflective of variations in the porosity and/or elastic modulus at near surface layers were performed on three differently finished silicon nitride flats, at the Argonne National Laboratory. The within specimen variability is believed to indicate real differences from location to location within a specimen. There is no apparent difference between specimens. An alternative procedure for characterizing variations in elastic modulus using a nanoindenter is discussed. 4 refs., 4 tabs.

  15. [Spinal injuries in children and adolescents].

    PubMed

    Schrödel, M; Hertlein, H

    2013-12-01

    Pediatric cervical spine injuries are rare. Knowledge of possible types of injury, physiological development and anomalies is necessary in order to not overlook the injury and to initiate suitable therapy. Description of the clinical assessment, Management of diagnostics and therapy of specific injuries. Based on a selective literature search and taking into consideration our own experience, typical injuries at the upper and lower cervical spine in pediatric patients are depicted. In the presence of neurological deficits, identification of the cause is crucial. Odontoid fractures and injuries to the second cervical vertebra are common in upper cervical spine injuries, compression fractures and facet joint dislocation injuries are common in lower cervical spine injuries. Depending on the location of the injury and on the grade of instability, specific therapy, including conservative treatment (orthosis, halo fixation) and operative treatment (internal fixation, fusion) might be necessary.

  16. Magmatic arc structure around Mount Rainier, WA, from the joint inversion of receiver functions and surface wave dispersion

    NASA Astrophysics Data System (ADS)

    Obrebski, Mathias; Abers, Geoffrey A.; Foster, Anna

    2015-01-01

    deep magmatic processes in volcanic arcs are often poorly understood. We analyze the shear wave velocity (VS) distribution in the crust and uppermost mantle below Mount Rainier, in the Cascades arc, resolving the main velocity contrasts based on converted phases within P coda via source normalization or receiver function (RF) analysis. To alleviate the trade-off between depth and velocity, we use long period phase velocities (25-100 s) obtained from earthquake surface waves, and at shorter period (7-21 s) we use seismic noise cross correlograms. We use a transdimensional Bayesian scheme to explore the model space (VS in each layer, number of interfaces and their respective depths, level of noise on data). We apply this tool to 15 broadband stations from permanent and Earthscope temporary stations. Most results fall into two groups with distinctive properties. Stations east of the arc (Group I) have comparatively slower middle-to-lower crust (VS = 3.4-3.8 km/s at 25 km depth), a sharp Moho and faster uppermost mantle (VS = 4.2-4.4 km/s). Stations in the arc (Group II) have a faster lower crust (VS = 3.7-4 km/s) overlying a slower uppermost mantle (VS = 4.0-4.3 km/s), yielding a weak Moho. Lower crustal velocities east of the arc (Group I) most likely represent ancient subduction mélanges mapped nearby. The lower crust for Group II ranges from intermediate to felsic. We propose that intermediate-felsic to felsic rocks represent the prearc basement, while intermediate composition indicates the mushy andesitic crustal magmatic system plus solidified intrusion along the volcanic conduits. We interpret the slow upper mantle as partial melt.

  17. Compliant joint

    NASA Technical Reports Server (NTRS)

    Eklund, Wayne D. (Inventor); Kerley, James J. (Inventor)

    1990-01-01

    A compliant joint is provided for prosthetic and robotic devices which permits rotation in three different planes. The joint provides for the controlled use of cable under motion. Perpendicular outer mounting frames are joined by swaged cables that interlock at a center block. Ball bearings allow for the free rotation of the second mounting frame relative to the first mounting frame within a predetermined angular rotation that is controlled by two stop devices. The cables allow for compliance at the stops and the cables allow for compliance in six degrees of freedom enabling the duplication or simulation of the rotational movement and flexibility of a natural hip or knee joint, as well as the simulation of a joint designed for a specific robotic component for predetermined design parameters.

  18. Joint Commission

    MedlinePlus

    Skip to main content The Joint Commission Log In | Request Guest Access Forgot password? | Log In Help Contact Us | Careers | JCR Web Store | Press Room Search Home Accreditation Accreditation Ambulatory Health ...

  19. Joint Problems

    MedlinePlus

    ... ligaments include: Rotator cuff injuries Tendonitis Frozen shoulder Fibromyalgia Carpal tunnel syndrome Bursitis. Visit the Arthritis topic ... to 90 years, although many have no symptoms. Fibromyalgia is usually first diagnosed in middle age, and ...

  20. [Posterior dislocation of the sternoclavicular joint].

    PubMed

    Mäkinen, Tatu; Madanat, Rami; Heinänen, Mikko; Brinck, Tuomas; Pajarinen, Jarkko

    2013-01-01

    Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

  1. [The temporomandibular joint].

    PubMed

    Louryan, S

    1992-10-01

    With its discordant articular surfaces and complete division in two cavities separated by a disk, the temporomandibular joint appears as a complex anatomical and functional entity. Combined movements involving anteroposterior gliding between the disk and temporal bone in the upper cavity, anteroposterior condyle translation, hinge and rotation movements between the disk and mandibular condyle contribute to the different movements of the jaw. With dental occlusion, the masticatory apparatus therefore includes five functionally coordinated articular compartments. Various impairments of the normal static and dynamic features of the temporomandibular joint may lead to relatively frequent pathological conditions which can be easily diagnosed by modern imaging and arthroscopic methods.

  2. Evaluation of composite bonded joints

    SciTech Connect

    Whitworth, H.A.; Othieno, M.; Yin, S.W.

    1995-12-31

    The present investigation evaluates the influence of joining technique on the static and fatigue behavior of composite bonded joints. Specimens used in this investigation were LDF AS4/PEKK graphite/thermoplastic composites and IM6/3501-6 graphite/poxy composite laminates. Joints were made by either adhesive bonding or fusing bonding. For the adhesive bonded joints, in some cases specimens were bonded without any surface pretreatment while in other cases the surfaces were either grit blast or corona. treated prior to bonding. For the fusion bonded joints, joints were prepared by either induction welding or thermabonding. In addition, some specimens were conditioned in a wet environment for thirty days in order to observe the influence of moisture on the static strengths. During fatigue testing, the residual stiffness was continually monitored in order to assess the extent of fatigue damage development.

  3. Elastic Wavespeed Images of Northern Chile Subduction Zone from the Joint Inversion of Body and Surface Waves: Structure of the Andean Forearc and the Double Seismic Zone

    NASA Astrophysics Data System (ADS)

    Comte, D.; Carrizo, D.; Roecker, S. W.; Peyrat, S.; Arriaza, R.; Chi, R. K.; Baeza, S.

    2015-12-01

    Partly in anticipation of an imminent megathrust earthquake, a significant amount of seismic data has been collected over the past several years in northern Chile by local deployments of seismometers. In this study we generate elastic wavespeed images of the crust and upper mantle using a combination of body wave arrival times and surface wave dispersion curves. The body wave data set consists of 130000 P and 108000 S wave arrival times generated by 12000 earthquakes recorded locally over a period of 25 years by networks comprising about 360 stations. The surface wave data set consists of Rayleigh wave dispersion curves determined from ambient noise recorded by 60 broad band stations from three different networks over a period of three years. Transit time biases due to an uneven distribution of noise were estimated using a technique based on that of Yao and van der Hilst (2009) and found to be as high as 5% for some station pairs. We jointly invert the body and surface wave observations to both improve the overall resolution of the crustal images and reduce the trade-off between shallow and deep structures in the images of the subducted slab. Of particular interest in these images are three regions of anomalous Vp/Vs: (1) An extensive zone of low Vp/Vs (1.68) correlates with trench-parallel magmatic belts emplaced in the upper continental crust. In the region of the coast and continental slope, low Vp/Vs corresponds to batholithic structures in the Jurassic-Cretaceous magmatic arc. Between the central depression and Domeyko Cordillera, low Vp/Vs correlates with the distribution of magmatic arcs of Paleocene-Oligocene and Eocene-Oligocene age. Low Vp/Vs also correlates with the location of the Mejillones Peninsula. (2) A region of high Vp/Vs occurs in what is most likely the serpentinized wedge of the subduction zone. (3) An additional zone of low Vp/Vs is located in the middle of the double seismic zone at depths of 90-110 km. This region may exist all along the

  4. Joint Inversion of Receiver Functions and Surface Wave Group Velocities from the MANAS data set to Determine Custal Thickness Variations in theTien Shan

    NASA Astrophysics Data System (ADS)

    Gilligan, A.; Priestley, K. F.; Roecker, S. W.

    2012-12-01

    The Tien Shan is the largest active intracontinental orgogenic belt on the Earth. To better understand the processes causing mountains to form in this location distant from a plate boundary, we analyze passive source seismic data collected on 40 broad band stations of the MANAS project (2005-2007) to determine variations in crustal thickness and wavespeed across the range. The linear MANAS array transects the Tien Shan just to the east of the Talas Fergana fault and extends from the Tarim Basin north over the Kokshal Range and across the Naryn Valley to the Kyrgyz Range and the Kazakh Shield. This data set has a denser station spacing (~10 km) than that available in previous studies. We combine P- and S-wave receiver functions with surface wave observations from both earthquakes and ambient noise analysis to reduce the ambiguity inherent in the images obtained from the techniques applied individually. In particular, fundamental-mode surface-wave dispersion observations are sensitive to absolute wavespeed averages rather than contrasts, while receiver functions are primarily sensitive to wavespeed contrasts and vertically integrated travel times rather than absolute wavespeeds. Moreover, analysis of the ambient noise allows dispersion measurements at shorter periods which improves constraints for the upper crust. We jointly invert P- and S-wave receiver functions, fundamental mode Rayleigh wave group velocity determined from 1.75 years of continuous seismic ambient noise for periods 4-28s, and group velocity data for periods 10-70s from the surface wave study of Acton et al. (2010). The resulting crustal model show a strong variation in the Moho depth across the range. We find the thickest crust (~60 km) beneath the Kokshal range, while that beneath the Naryn Valley, in the middle of the Tien Shan is thin (~45 km) and is of similar thickness to that beneath the Tarim Basin and Kazakh shield. This suggests a lack of crustal shortening, or shortening of a previously

  5. Knee Injuries

    MedlinePlus

    ... injuries. Try weightlifting to strengthen your muscles and stretching, Pilates, and yoga to improve your flexibility because ... lead to injuries and inflammation from overuse. Regular stretching can help. After an injury or surgery has ...

  6. Eye Injuries

    MedlinePlus

    The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or ...

  7. Sports Injuries

    MedlinePlus

    ... sometimes you can injure yourself when you play sports or exercise. Accidents, poor training practices, or improper ... can also lead to injuries. The most common sports injuries are Sprains and strains Knee injuries Swollen ...

  8. Biomechanical and injury response of human foot and ankle under complex loading.

    PubMed

    Shin, Jaeho; Untaroiu, Costin D

    2013-10-01

    Ankle and subtalar joint injuries of vehicle front seat occupants are frequently recorded during frontal and offset vehicle crashes. A few injury criteria for foot and ankle were proposed in the past; however, they addressed only certain injury mechanisms or impact loadings. The main goal of this study was to investigate numerically the tolerance of foot and ankle under complex loading which may appear during automotive crashes. A previously developed and preliminarily validated foot and leg finite element (FE) model of a 50th percentile male was employed in this study. The model was further validated against postmortem human subjects (PMHS) data in various loading conditions that generates the bony fractures and ligament failures in ankle and subtalar regions observed in traffic accidents. Then, the foot and leg model were subjected to complex loading simulated as combinations of axial, dorsiflexion, and inversion loadings. An injury surface was fitted through the points corresponding to the parameters recorded at the time of failure in the FE simulations. The compelling injury predictions of the injury surface in two crash simulations may recommend its application for interpreting the test data recorded by anthropometric test devices (ATD) during crash tests. It is believed that the methodology presented in this study may be appropriate for the development of injury criteria under complex loadings corresponding to other body regions as well.

  9. Quantitative constraints on the lithospheric mantle discontinuity structure in eastern Canada from joint analysis of receiver function and surface wave data

    NASA Astrophysics Data System (ADS)

    Bailey, I. W.; Miller, M. S.; Darbyshire, F. A.

    2011-12-01

    Previous work has suggested that the Archean craton of central and eastern Canada contains a number of relict slabs, frozen in and radiating out from the center. This observation has been used to suggest that the craton's existence is due to the formation and dying out of ancient (~2 Ga) subduction zones at the craton edges in progressive Wilson cycles, leaving a chemically depleted and buoyant slab after each stage. Miller & Eaton (2010) used teleseismic S receiver functions to image a deep (200-260 km) sharp lithosphere-asthenosphere boundary and a number of negative polarity shallower, mid-lithospheric discontinuities. However, noise in the data and insufficient sampling from only 8 seismic stations meant that the discontinuities could only be interpreted using comparisons with results based on surface wave and heat flow analyses. To better understand the discontinuity structure across central and eastern Canada, we utilise data from a combination of 32 permanent and temporary broadband stations including those from the HuBLE experiment. From this extended dataset we attempt to constrain evidence for the observed discontinuities more quantitatively by combining both P and S receiver functions with Rayleigh wave phase velocity data in Monte Carlo based joint inversions for shear wave velocity structure. The crustal thickness and velocity is initially constrained by results from active source experiments and stacking of receiver functions. Our Monte Carlo approach allows us to investigate uncertainty in the Vp, density and attenuation parameters on the inferred Vs result and discontinuities, allowing for better constraints on recently reported internal structure of continental lithosphere in both Canada and other cratonic regions.

  10. Posterior labral injury in contact athletes.

    PubMed

    Mair, S D; Zarzour, R H; Speer, K P

    1998-01-01

    Nine athletes (seven football offensive linemen, one defensive lineman, and one lacrosse player) were found at arthroscopy to have posterior labral detachment from the glenoid. In our series, this lesion is specific to contact athletes who engage their opponents with arms in front of the body. All patients had pain with bench pressing and while participating in their sport, diminishing their ability to play effectively. Conservative measures were ineffective in relieving their symptoms. Examination under anesthesia revealed symmetric glenohumeral translation bilaterally, without evidence of posterior instability. Treatment consisted of glenoid rim abradement and posterior labral repair with a bioabsorbable tack. All patients returned to complete at least one full season of contact sports and weightlifting without pain (minimum follow-up, > or = 2 years). Although many injuries leading to subluxation of the glenohumeral joint occur when an unanticipated force is applied, contact athletes ready their shoulder muscles in anticipation of impact with opponents. This leads to a compressive force at the glenohumeral joint. We hypothesize that, in combination with a posteriorly directed force at impact, the resultant vector is a shearing force to the posterior labrum and articular surface. Repeated exposure leads to posterior labral detachment without capsular injury. Posterior labral reattachment provides consistently good results, allowing the athlete to return to competition.

  11. Achilles tendon injuries in athletes.

    PubMed

    Kvist, M

    1994-09-01

    varus is found in athletes with Achilles tendon overuse injuries, reflecting the predisposing role of ankle joint overpronation. Athletes with the major stress in lower extremities have often a limited range of motion in the passive dorsiflexion of the ankle joint and total subtalar joint mobility, which seems to be predisposing factor for these injuries. Various predisposing transient factors are found in about one-third of athletes with Achilles tendon overuse injuries; of these, traumatic factors (mostly minor injuries) predominate. The typical histological features of chronically inflamed paratendineal tissue of the Achilles tendon are profound proliferation of loose, immature connective tissue and marked obliterative and degenerative alterations in the blood vessels. These changes cause continuing leakage of plasma proteins, which may have an important role in the pathophysiology of these injuries. The chronically inflamed paratendineal tissues of the Achilles tendon do not seem to have enough capacity to form mature connective tissue.

  12. Hypermobile joints

    MedlinePlus

    ... A.M. Editorial team. Related MedlinePlus Health Topics Joint Disorders Browse the Encyclopedia A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an ...

  13. Muscle strain injuries.

    PubMed

    Garrett, W E

    1996-01-01

    One of the most common injuries seen in the office of the practicing physician is the muscle strain. Until recently, little data were available on the basic science and clinical application of this basic science for the treatment and prevention of muscle strains. Studies in the last 10 years represent action taken on the direction of investigation into muscle strain injuries from the laboratory and clinical fronts. Findings from the laboratory indicate that certain muscles are susceptible to strain injury (muscles that cross multiple joints or have complex architecture). These muscles have a strain threshold for both passive and active injury. Strain injury is not the result of muscle contraction alone, rather, strains are the result of excessive stretch or stretch while the muscle is being activated. When the muscle tears, the damage is localized very near the muscle-tendon junction. After injury, the muscle is weaker and at risk for further injury. The force output of the muscle returns over the following days as the muscle undertakes a predictable progression toward tissue healing. Current imaging studies have been used clinically to document the site of injury to the muscle-tendon junction. The commonly injured muscles have been described and include the hamstring, the rectus femoris, gastrocnemius, and adductor longus muscles. Injuries inconsistent with involvement of a single muscle-tendon junction proved to be at tendinous origins rather than within the muscle belly. Important information has also been provided regarding injuries with poor prognosis, which are potentially repairable surgically, including injuries to the rectus femoris muscle, the hamstring origin, and the abdominal wall. Data important to the management of common muscle injuries have been published. The risks of reinjury have been documented. The early efficacy and potential for long-term risks of nonsteroidal antiinflammatory agents have been shown. New data can also be applied to the field

  14. 3D kinematics of the tarsal joints from magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Hirsch, Bruce E.; Udupa, Jayaram K.; Okereke, Enyi; Hillstrom, Howard J.; Siegler, Sorin; Ringleb, Stacie I.; Imhauser, Carl W.

    2001-09-01

    We have developed a method for analyzing motion at skeletal joints based on the 3D reconstruction of magnetic resonance (MR) image data. Since the information about each voxel in MR images includes its location in the scanner, it follows that information is available for each organ whose 3D surface is computed from a series of MR slices. In addition, there is information on the shape and orientation of each organ, and the contact areas of adjacent bones. By collecting image data in different positions we can calculate the motion of the individual bones. We have used this method to study human foot bones, in order to understand normal and abnormal foot function. It has been used to evaluate patients with tarsal coalitions, various forms of pes planus, ankle sprains, and several other conditions. A newly described feature of this system is the ability to visualize the contact area at a joint, as determined by the region of minimum distance. The display of contact area helps understand abnormal joint function. Also, the use of 3D imaging reveals motions in joints which cannot otherwise be visualized, such as the subtalar joint, for more accurate diagnosis of joint injury.

  15. Management of Extensor Tendon Injuries

    PubMed Central

    Griffin, M; Hindocha, S; Jordan, D; Saleh, M; Khan, W

    2012-01-01

    Extensor tendon injuries are very common injuries, which inappropriately treated can cause severe lasting impairment for the patient. Assessment and management of flexor tendon injuries has been widely reviewed, unlike extensor injuries. It is clear from the literature that extensor tendon repair should be undertaken immediately but the exact approach depends on the extensor zone. Zone I injuries otherwise known as mallet injuries are often closed and treated with immobilisaton and conservative management where possible. Zone II injuries are again conservatively managed with splinting. Closed Zone III or ‘boutonniere’ injuries are managed conservatively unless there is evidence of displaced avulsion fractures at the base of the middle phalanx, axial and lateral instability of the PIPJ associated with loss of active or passive extension of the joint or failed non-operative treatment. Open zone III injuries are often treated surgically unless splinting enable the tendons to come together. Zone V injuries, are human bites until proven otherwise requires primary tendon repair after irrigation. Zone VI injuries are close to the thin paratendon and thin subcutaneous tissue which strong core type sutures and then splinting should be placed in extension for 4-6 weeks. Complete lacerations to zone IV and VII involve surgical primary repair followed by 6 weeks of splinting in extension. Zone VIII require multiple figure of eight sutures to repair the muscle bellies and static immobilisation of the wrist in 45 degrees of extension. To date there is little literature documenting the quality of repairing extensor tendon injuries however loss of flexion due to extensor tendon shortening, loss of flexion and extension resulting from adhesions and weakened grip can occur after surgery. This review aims to provide a systematic examination method for assessing extensor injuries, presentation and management of all type of extensor tendon injuries as well as guidance on

  16. ANATOMICAL RELATIONSHIP OF THE SUPRASCAPULAR NERVE TO THE CORACOID PROCESS, ACROMIOCLAVICULAR JOINT AND ACROMION

    PubMed Central

    Terra, Bernardo Barcellos; Gaspar, Eric Figueiredo; Siqueira, Karina Levy; Filho, Nivaldo Souza Cardozo; Monteiro, Gustavo Cará; Andreoli, Carlos Vicente; Ejnisman, Benno

    2015-01-01

    Objective: To establish the anatomical relationship of the suprascapular nerve (SSN) located in the suprascapular notch, to the medial border of the base of the coracoid process, the acromial joint surface of the acromioclavicular joint and the anterolateral border of the acromion. Methods: We dissected 16 shoulders of 16 cadavers (9 males and 7 females). The distances from the suprascapular nerve (at its passage beneath the transverse ligament) to certain fixed points on the medial border of the base of the coracoid process, the acromial joint surface of the acromioclavicular joint, and the anterolateral border of the acromion were measured with the aid of calipers and correlated with age and sex. Cadavers with previous surgical interventions were excluded. Results: The mean measurements from the notch of the suprascapular nerve were: 3.9 cm to the medial border of the base of the coracoid process (ranging from 3.1 cm to 5.2 cm); 4.7 cm to the acromioclavicular joint (ranging from 3.9 cm to 5.2 cm); and 6.1 cm to the anterolateral border of the acromion (ranging from 5.7 cm to 6.8 cm). Conclusion: Accurate anatomical knowledge of the nerves of the anterior region of the shoulder is essential in order to avoid iatrogenic injuries and to achieve satisfactory results in surgical treatment for shoulder diseases, whether performed as open or arthroscopic procedures. PMID:27022551

  17. Improved vision in forensic documentation: forensic 3D/CAD-supported photogrammetry of bodily injury external surfaces combined with volumetric radiologic scanning of bodily injury internal structures provides more investigative leads and stronger forensic evidence

    NASA Astrophysics Data System (ADS)

    Thali, Michael J.; Braun, Marcel; Kneubuehl, Beat P.; Brueschweiler, Walter; Vock, Peter; Dirnhofer, Richard

    2000-05-01

    In the field of the documentation of forensics-relevant injuries, from the reconstructive point of view, the Forensic, 3D/CAD-supported Photometry plays an important role; particularly so when a detailed 3D reconstruction is vital. This was demonstrated with an experimentally-produced 'injury' to a head model, the 'skin-skull-brain model'. The injury-causing instrument, drawn from a real forensic case, was a specifically formed weapon.

  18. Hallucal tarsometatarsal joint in Australopithecus afarensis.

    PubMed

    Latimer, B; Lovejoy, C O

    1990-06-01

    Hallucal tarsometatarsal joints from African pongids, modern humans, and Australopithecus afarensis are compared to investigate the anatomical and mechanical changes that accompanied the transition to terrestrial bipedality. Features analyzed include the articular orientation of the medial cuneiform, curvature of the distal articular surface of the medial cuneiform, and the articular configuration of the hallucal metatarsal proximal joint surface. Morphological characteristics of the hallucal tarsometatarsal joint unequivocally segregate quadrupedal pongids and bipedal hominids.

  19. Invited Hand Article: Current Concepts in Treatment of Fracture-Dislocations of the Proximal Interphalangeal Joint

    PubMed Central

    Haase, Steven C.; Chung, Kevin C.

    2014-01-01

    Background Proximal interphalangeal joint fracture-dislocations are common injuries that require expedient and attentive treatment for the best outcomes. Management can range from protective splinting and early mobilization to complex operations. In this review, the current concepts surrounding the managment of these injuries are reviewed. Methods A literature review was performed of all recent articles pertaining to proximal interphalangeal joint fracture-dislocation, with specific focus on middle phalangeal base fractures. Where appropriate, older articles, or articles on closely related injury types were included for completeness. The methodology and outcomes of each study were analyzed. Results When small avulsion fractures are present, good results are routinely obtained with reduction and early mobilization of stable injuries. Strategies for management of the unstable dorsal fracture-dislocation have evolved over time. To provide early stability, a variety of techniques have evolved, including closed, percutaneous, external, and internal fixation methods. Although each of these techniques can be successful in skilled hands, none have been subjected to rigorous, prospective, comparative trials. Volar dislocations fare less well, with significant loss of motion in many studies. Pilon fractures represent the most complicated injuries, and return of normal motion is not expected. Conclusion The best outcomes can be achieved by (1) establishing enough stability to allow early motion, (2) restoring gliding joint motion rather than non-congruent motion, and (3) restoring the articular surface congruity when possible. Although the majority of literature on this topic consists of expert opinion and retrospective case series, the consensus appears to favor less invasive techniques whenever possible. PMID:25415092

  20. Further studies into proximal interphalangeal joint dimensions for the design of a surface replacement prosthesis: medullary cavities and transverse plane shapes.

    PubMed

    Ash, H E; Unsworth, A

    1997-01-01

    The proximal and middle phalanges from 83 proximal interphalangeal joints (PIPJs) were set in clear plastic and sectioned in the transverse plane leaving the heads whole. The sections were cleaned, shadowgraphed and measured. The medullary canals were marked on sagittal and frontal plane shadowgraphs of the intact bones and analysed. The information was then used in the design of a surface replacement prosthesis for the PIPJs. The main dorsal surface of the proximal phalanx (PP) was found to be angled to the longitudinal baseline of the bone by a mean of 5.19 degrees. This angle increased just proximal to the phalangeal head to a mean of 11.84 degrees. The mean ratio between these angles was 2.71. The phalangeal shaft bone was thicker laterally than dorsally and palmarly, and thicker dorsally than palmarly for the proximal and middle phalanges throughout the length of the bone. The shape and size of the transverse cross-section of the medullary canal changed throughout the length of the shaft. The centreline of the PP medullary canal coincided with the midline of the bone in the frontal plane and was approximately a straight line along the length of the canal. In the sagittal plane the centreline was slightly palmar to the midline and the angle between it and the longitudinal baseline of the bone changed along the length of the canal. In the region of the shaft just proximal to the PP head (where the stem of a surface replacement prosthesis would fit) the mean angle was 10.63 degrees. The centreline was offset dorsally from the centre of rotation of the PIPJ by a mean of 0.83 mm, 0.83 mm, 0.80 mm and 0.57 mm for the index, middle, ring and little fingers respectively, with an overall mean of 0.76 mm. The mean PP head heights (transverse plane) were 9.17 mm, 9.33 mm, 8.73 mm and 7.40 mm and the mean PP widths (transverse plane) were 12.86 mm, 13.25 mm, 12.75 mm and 10.54 mm for the index, middle, ring and little fingers respectively. The mean angle between the

  1. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  2. Joint Warrior

    DTIC Science & Technology

    2011-05-04

    hour per response , including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...reflect my own personal views and are not necessarily endorsed by the NWC or the Department of the Navy. 14. ABSTRACT The way we fight wars has been...evolving over thousands of years. Today, the U.S. Navy, finds itself in the post- modern area of war fighting . Joint warfare is the latest

  3. Computational modeling to predict mechanical function of joints: application to the lower leg with simulation of two cadaver studies.

    PubMed

    Liacouras, Peter C; Wayne, Jennifer S

    2007-12-01

    Computational models of musculoskeletal joints and limbs can provide useful information about joint mechanics. Validated models can be used as predictive devices for understanding joint function and serve as clinical tools for predicting the outcome of surgical procedures. A new computational modeling approach was developed for simulating joint kinematics that are dictated by bone/joint anatomy, ligamentous constraints, and applied loading. Three-dimensional computational models of the lower leg were created to illustrate the application of this new approach. Model development began with generating three-dimensional surfaces of each bone from CT images and then importing into the three-dimensional solid modeling software SOLIDWORKS and motion simulation package COSMOSMOTION. Through SOLIDWORKS and COSMOSMOTION, each bone surface file was filled to create a solid object and positioned necessary components added, and simulations executed. Three-dimensional contacts were added to inhibit intersection of the bones during motion. Ligaments were represented as linear springs. Model predictions were then validated by comparison to two different cadaver studies, syndesmotic injury and repair and ankle inversion following ligament transection. The syndesmotic injury model was able to predict tibial rotation, fibular rotation, and anterior/posterior displacement. In the inversion simulation, calcaneofibular ligament extension and angles of inversion compared well. Some experimental data proved harder to simulate accurately, due to certain software limitations and lack of complete experimental data. Other parameters that could not be easily obtained experimentally can be predicted and analyzed by the computational simulations. In the syndesmotic injury study, the force generated in the tibionavicular and calcaneofibular ligaments reduced with the insertion of the staple, indicating how this repair technique changes joint function. After transection of the calcaneofibular

  4. Metatarsophalangeal joints of Australopithecus afarensis.

    PubMed

    Latimer, B; Lovejoy, C O

    1990-09-01

    Metatarsophalangeal joints from African pongids, modern humans, and Australopithecus afarensis are compared to investigate the anatomical and mechanical changes that accompanied the transition to terrestrial bipedality. Features analyzed include the shape and orientation of the metatarsal heads, excursion of the metatarsophalangeal joints, and orientation of the basal articular surface of the proximal phalanges. These features unequivocally segregate quadrupedal pongids and bipedal hominids and demonstrate a clear adaptation to terrestrial bipedality in the Hadar pedal skeleton.

  5. Snowboard injuries.

    PubMed

    Pino, E C; Colville, M R

    1989-01-01

    A retrospective survey of 267 snowboarders was undertaken to determine the population at risk and types and mechanisms of injuries sustained in this sport. Snowboarders are young (average age, 21 years), male (greater than 90%), view themselves in average or above average physical condition (96%), and have varied sports interests. One hundred ten injuries that resulted in a physician visit were reported. Ligament sprains, fractures, and contusions were the most frequent types of injury. Fifty percent of all injuries occurred in the lower extremities, with ankle injuries being the most common. Snowboard riders using equipment with increased ankle support seem to be more protected from lower extremity injuries. The lower extremity injuries were concentrated in the forward limb of the snowboarder, where the rider's weight is disproportionately distributed. Differences in the mechanism and spectrum of injury between snowboarding and skiing injuries were noted, including: impact rather than torsion as the major mechanism of injury, a significant lack of thumb injuries, comparative increase in ankle injuries, a decrease in knee injuries, and a higher percentage of upper extremity injuries.

  6. Gasoline immersion injury

    SciTech Connect

    Simpson, L.A.; Cruse, C.W.

    1981-01-01

    Chemical burns and pulmonary complications are the most common problems encountered in the patient immersed in gasoline. Our patient demonstrated a 46-percent total-body-surface area, partial-thickness chemical burn. Although he did not develop bronchitis or pneumonitis, he did display persistent atelectasis, laryngeal edema, and subsequent upper airway obstruction. This had not previously been reported in gasoline inhalation injuries. Hydrocarbon hepatitis secondary to the vascular endothelial damage is apparently a reversible lesion with no reported long-term sequelae. Gasoline immersion injuries may be a series multisystem injury and require the burn surgeon to take a multisystem approach to its diagnosis and treatment.

  7. Lightning and thermal injuries.

    PubMed

    Sanford, Arthur; Gamelli, Richard L

    2014-01-01

    treated. The exact mechanism of nerve injury has not been explained, but both direct injury by electrical current overload or a vascular cause receive the most attention. Because electrical injuries carry both externally visible cutaneous injuries and possible hidden musculoskeletal damage, conventional burn resuscitation formulas based on body surface area injured may not provide enough fluid to maintain urine output. Damaged muscle resulting in swelling within the investing fascia of an extremity may result in compartment syndromes, requiring further attention. If myoglobin has been detected in the urine, treatment is aggressive volume resuscitation and possibly alkalinization of the urine or mannitol is given IV push to minimize pigment precipitation in the renal tubules. Approximately 15% of electrical burn victims also sustain traumatic injuries. This is because of falls from height or being thrown against an object. The tetanic contractions that result from exposure to electrical injury cause imbalance in flexor versus extensor muscles, with the flexor groups being stronger. Not only is the victim unable to release from the electrical contact, but they are at risk for fracture of bones from this prolonged muscular contracture. Neurologic and psychological symptoms were the most common sequelae of electrical and lightning injuries. Many of these symptoms are nonspecific, and they often do not appear until several months after the injury. A full neurologic examination must be performed on admission, documenting initial presentation and at any change in symptoms. Electrical injuries can have devastating consequences. Prevention of electrical injuries is clearly the preferable strategy for treatment.

  8. Snowboarding injuries.

    PubMed

    Sachtleben, Thomas R

    2011-01-01

    Snowboarding has gained immense popularity during the past 30 years and continues to appeal to many young participants. Injury patterns and characteristics of injuries seen commonly in snowboarders have rapidly evolved during this time. Risk factors have emerged, and various methods of reducing injuries to snowboarders have been investigated. It is important that medical providers are knowledgeable about this growing sport and are prepared to adequately evaluate and treat snowboarding injuries. This article will review the issues and discuss diagnostic and treatment principles regarding injuries seen commonly in snowboarders. Injury prevention should be emphasized, particularly with young riders and beginners.

  9. Ultrasonic Probing Of Complexly Shaped Joints

    NASA Technical Reports Server (NTRS)

    Madaras, Eric I.

    1993-01-01

    Technique developed involves use of ultrasonics to inspect first bond surfaces of solid-rocket-motor joints. By fitting pieces of insulating materials to mate exactly with complicated shapes of affected parts of insulation, complicated shapes redefined into simpler ones probed more easily. When technique used to insonify from insulation side, one readily detects difference between disbond and good bond. Same technique applied to field tang joints, field clevis joints, and aft-dome-to-fixed-nozzle-housing attachment points. Although developed for inspecting joints in solid rocket motors, also applicable to nondestructive evaluation of other complicated joints.

  10. [Ankle joint arthritis--etiology, diagnosis and treatment].

    PubMed

    Uri, Ofir; Haim, Amir

    2008-11-01

    Ankle joint arthritis causes functional limitation and affects the quality of life many patients. It follows traumatic injuries, inflammatory joint arthritis, primary osteoarthritis, hemochromatosis and infections. Understanding the unique anatomy and biomechanics of the ankle is important for diagnosis and treatment of ankle joint pathology. The treatment of ankle joint arthritis has advanced considerably in recent years and it is still a surgical challenge. Total ankle replacement seems to be a promising form of treatment, even though current data does not demonstrate advantages over ankle joint arthrodesis.

  11. Effects of ankle joint cooling on peroneal short latency response.

    PubMed

    Hopkins, J Ty; Hunter, Iain; McLoda, Todd

    2006-01-01

    While cryotherapy has direct physiological effects on contractile tissues, the extent to which joint cooling affects the neuromuscular system is not well understood. The purpose of the study was to detect changes in ankle dynamic restraint (peroneal short latency response and muscle activity amplitude) during inversion perturbation following ankle joint cryotherapy. A 2x3 factorial design was used to compare reaction time and EMG amplitude data of treatment conditions (cryotherapy and control) across time (pre-treatment, post-treatment, and 30 min post-treatment). Thirteen healthy volunteers (age 23 ± 4 yrs, ht 1.76 ± 0.09 m, mass 78.8 ± 16.6 kg), with no history of lower extremity joint injury participated in this study. Surface EMG was collected from the peroneus longus (PL) of the dominant leg during an ankle inversion perturbation triggered while walking. Subjects walked the length of a 6.1 m runway 30 times. A trap door mechanism, inducing inversion perturbation, was released at heel contact during six randomly selected trials for each leg. Following baseline measurements, a 1.5 L bag of crushed ice was applied to the lateral ankle of subjects in the treatment group with an elastic wrap. A bag similar in weight and consistency was applied to the lateral ankle of subjects in the control group. A repeated measures ANOVA was used to compare treatment conditions across time (p < 0.05). Maximum inversion range of motion was 28.4 ± 1.8° for all subjects. No overall condition by time difference was detected (p > 0.05) for PL reaction time. Average RMS EMG, normalized to an isometric reference position, increased in the cryotherapy group at the 30 min post-treatment interval relative to the control group (p < 0.05). Joint cooling does not result in deficiencies in reaction time or immediate muscle activation following inversion perturbation compared to a control. Key PointsJoint cooling is used as a treatment intervention prior to activity. Whether ankle cooling

  12. Pathological Knee Joint Motion Analysis By High Speed Cinephotography

    NASA Astrophysics Data System (ADS)

    Baumann, Jurg U.

    1985-02-01

    The use of cinephotography for evaluation of disturbed knee joint function was compared in three groups of patients. While a sampling rate of 50 images per second was adequate for patients with neuromuscular disorders, a higher frequency of around 300 i.p.s. is necessary in osteoarthritis and ligamentous knee joint injuries, but the task of digitizing is prohibitive unless automated.

  13. Thermal Applications as a Determiner of Joint Flexibility.

    ERIC Educational Resources Information Center

    Grobaker, Mark Randolph; Stull, G. Alan

    This study investigates the relative effects of thermal applications of varying temperatures on the flexibility of specified joints. Subjects were 14 male college students ranging in age from 17 to 22 years with no previous joint injury or orthopedic disability. Each subject became familiar with the experimental design and was asked not to engage…

  14. Metatarsal Shaft Fracture with Associated Metatarsophalangeal Joint Dislocation

    PubMed Central

    2016-01-01

    Metatarsophalangeal joint dislocations of lesser toes are often seen in the setting of severe claw toes. Traumatic irreducible dislocations have been reported in rare cases following both low-energy and high-energy injuries to the forefoot. In this case report, I present a previously unreported association of a metatarsal shaft fracture with metatarsophalangeal joint dislocation of a lesser toe. PMID:27597914

  15. A study of lubrication, processing conditions, and material combinations that affect the wear of micro-textured-carbide coated cobalt-chromium-molybdenum alloy surfaces used for artificial joints implants

    NASA Astrophysics Data System (ADS)

    Ettienne-Modeste, Geriel A.

    Total joint replacement remains one of the most successful treatments for arthritis. The most common materials used for artificial joints are metals (e.g., cobalt-chrome alloys or titanium alloys), which articulate against ultra-high molecular weight polyethylene. Wear related failures of artificial joints may be reduced with the use of novel micro-textured carbide surfaces. The micro-textured carbide surfaces were deposited on a CoCrMo alloy using microwave plasma-assisted chemical vapor deposition. Wear tests were conducted to determine wear mechanisms and properties of the micro-textured surfaces. The research presented in this thesis addresses: (1) rheolgoical behavior of bovine calf serum with and without antibacterial agents to determine whether they can be used as appropriate models for synovial fluid, (2) the wear behavior of the micro-textured CoCrMo surface system, and (3) the mechanical and material properties of the micro-textured CoCrMo alloy surface relevant to wear performance. The rheological studies showed that the apparent viscosity of bovine calf serum increased with an increase in concentration before and after the serum was used for wear testing. The wear analysis showed that the processing conditions (2hr deposition vs. 4hr deposition times) affected the wear properties. The 2hr carbide-on-carbide lubricated in 50% BCS produced the lowest wear factor and rate for the five wear couple systems containing the carbide disk or plate material. Greater wear was produced in serum without penicillin/streptomycin (P/S) compared to the serum containing P/S. A greater carbide coating thickness 10 (micrometers) was produced during the 4hr deposition time than for the 2hr deposition (˜3mum). The nano-hardness value was higher than the micro-hardness for both the 4hr and 2hr carbide surfaces. The micro-hardness results of the worn carbide surfaces showed that an increase in BCS concentration from 0% to 100% increased the micro-hardness (HV) for carbide

  16. Corneal injury

    MedlinePlus

    ... as sand or dust Ultraviolet injuries: Caused by sunlight, sun lamps, snow or water reflections, or arc- ... a corneal injury if you: Are exposed to sunlight or artificial ultraviolet light for long periods of ...

  17. Inhalation Injuries

    MedlinePlus

    ... you can inhale that can cause acute internal injuries. Particles in the air from fires and toxic ... and lung diseases worse. Symptoms of acute inhalation injuries may include Coughing and phlegm A scratchy throat ...

  18. ACL Injuries

    MedlinePlus

    ... Diet Plans Nutrients and Nutritional Info Sugar and Sugar Substitutes Exercise and Fitness Exercise Basics Sports Safety Injury ... Diet Plans Nutrients and Nutritional Info Sugar and Sugar Substitutes Exercise and Fitness Exercise Basics Sports Safety Injury ...

  19. Head Injuries

    MedlinePlus

    ... scalp internal head injuries, which may involve the skull, the blood vessels within the skull, or the brain Fortunately, most childhood falls or ... knock the brain into the side of the skull or tear blood vessels. Some internal head injuries ...

  20. Urethral Injuries

    MedlinePlus

    ... and Related Injuries (Video) Rotator Cuff Injury (News) Violent Video Games May Not 'Desensitize' Players, Brain Scans ... Comfort Am I Correct? More Videos News HealthDay Violent Video Games May Not 'Desensitize' Players, Brain Scans ...

  1. The Interface of Mechanics and Nociception in Joint Pathophysiology: Insights From the Facet and Temporomandibular Joints.

    PubMed

    Sperry, Megan M; Ita, Meagan E; Kartha, Sonia; Zhang, Sijia; Yu, Ya-Hsin; Winkelstein, Beth

    2017-02-01

    Chronic joint pain is a widespread problem that frequently occurs with aging and trauma. Pain occurs most often in synovial joints, the body's load bearing joints. The mechanical and molecular mechanisms contributing to synovial joint pain are reviewed using two examples, the cervical spinal facet joints and the temporomandibular joint (TMJ). Although much work has focused on the macroscale mechanics of joints in health and disease, the combined influence of tissue mechanics, molecular processes, and nociception in joint pain has only recently become a focus. Trauma and repeated loading can induce structural and biochemical changes in joints, altering their microenvironment and modifying the biomechanics of their constitutive tissues, which themselves are innervated. Peripheral pain sensors can become activated in response to changes in the joint microenvironment and relay pain signals to the spinal cord and brain where pain is processed and perceived. In some cases, pain circuitry is permanently changed, which may be a potential mechanism for sustained joint pain. However, it is most likely that alterations in both the joint microenvironment and the central nervous system (CNS) contribute to chronic pain. As such, the challenge of treating joint pain and degeneration is temporally and spatially complicated. This review summarizes anatomy, physiology, and pathophysiology of these joints and the sensory pain relays. Pain pathways are postulated to be sensitized by many factors, including degeneration and biochemical priming, with effects on thresholds for mechanical injury and/or dysfunction. Initiators of joint pain are discussed in the context of clinical challenges including the diagnosis and treatment of pain.

  2. Cycling injuries.

    PubMed Central

    Cohen, G. C.

    1993-01-01

    Bicycle-related injuries have increased as cycling has become more popular. Most injuries to recreational riders are associated with overuse or improper fit of the bicycle. Injuries to racers often result from high speeds, which predispose riders to muscle strains, collisions, and falls. Cyclists contact bicycles at the pedals, seat, and handlebars. Each is associated with particular cycling injuries. Images Figure 1 Figure 3 Figure 4 Figure 5 PMID:8471908

  3. Joint bleeding in factor VIII deficient mice causes an acute loss of trabecular bone and calcification of joint soft tissues which is prevented with aggressive factor replacement

    PubMed Central

    Lau, Anthony G.; Sun, Junjiang; Hannah, William B.; Livingston, Eric W.; Heymann, Dominique; Bateman, Ted A.; Monahan, Paul E.

    2015-01-01

    Introduction While chronic degenerative arthropathy is the main morbidity of hemophilia, a very high prevalance of low bone density is also seen in men and boys with hemophilia. The current study investigates bone degradation in the knee joint of hemophilic mice resulting from hemarthrosis and the efficacy of aggressive treatment with factor VIII in the period surrounding injury to prevent bone pathology. Methods Skeletally mature factor VIII knock-out mice were subjected to knee joint hemorrhage induced by puncture of the left knee joint capsule. Mice received either intravenous Factor VIII treatment or placebo immediately prior to injury and at hours 4, 24, 48, 72 and 96 after hemorrhage. Mice were euthanized two-weeks after injury and the joint morphology and loss of bone in the proximal tibia was assessed using microCT imaging. Results Quantitative microCT imaging of the knee joint found acute bone loss at the proximal tibia following injury including loss of trabecular bone volumetric density and bone mineral density, as well as trabecular connectivity density, number, and thickness. Unexpectedly, joint injury also resulted in calcification of the joint soft tissues including the tendons, ligaments, menisci, and cartilage. Treatment with factor VIII prevented this bone and soft tissue degeneration. Conclusion Knee joint hemorrhage resulted in acute changes of adjacent bone including loss of bone density and mineralization of joint soft tissues. The rapid calcification and loss of bone has implications for the initiation and progression of osteoarthritic degradation following joint bleeding. PMID:24712867

  4. Suppression of alkali-induced oxidative injury in the cornea by mesenchymal stem cells growing on nanofiber scaffolds and transferred onto the damaged corneal surface.

    PubMed

    Cejkova, Jitka; Trosan, Peter; Cejka, Cestmir; Lencova, Anna; Zajicova, Alena; Javorkova, Eliska; Kubinova, Sarka; Sykova, Eva; Holan, Vladimir

    2013-11-01

    The purpose of this study was to investigate whether rabbit bone marrow-derived mesenchymal stem cells (MSCs) effectively decrease alkali-induced oxidative stress in the rabbit cornea. The alkali (0.15 N NaOH) was applied on the corneas of the right eyes and then rinsed with tap water. In the first group of rabbits the injured corneas remained untreated. In the second group MSCs were applied on the injured corneal surface immediately after the injury and eyelids sutured for two days. Then the sutures were removed. In the third group nanofiber scaffolds seeded with MSCs (and in the fourth group nanofibers alone) were transferred onto the corneas immediately after the injury and the eyelids sutured. Two days later the eyelid sutures were removed together with the nanofiber scaffolds. The rabbits were sacrificed on days four, ten or fifteen after the injury, and the corneas were examined immunohistochemically, morphologically, for the central corneal thickness (taken as an index of corneal hydration) using an ultrasonic pachymeter and by real-time PCR. Results show that in untreated injured corneas the expression of malondialdehyde (MDA) and nitrotyrosine (NT) (important markers of lipid peroxidation and oxidative stress) appeared in the epithelium. The antioxidant aldehyde dehydrogenase 3A1 (ALDH3A1) decreased in the corneal epithelium, particularly in superficial parts, where apoptotic cell death (detected by active caspase-3) was high. (In control corneal epithelium MDA and NT are absent and ALDH3A1 highly present in all layers of the epithelium. Cell apoptosis are sporadic). In injured untreated cornea further corneal disturbances developed: The expressions of matrix metalloproteinase 9 (MMP9) and proinflammatory cytokines, were high. At the end of experiment (on day 15) the injured untreated corneas were vascularized and numerous inflammatory cells were present in the corneal stroma. Vascular endothelial growth factor (VEGF) expression and number of macrophages

  5. Orienteering injuries

    PubMed Central

    Folan, Jean M.

    1982-01-01

    At the Irish National Orienteering Championships in 1981 a survey of the injuries occurring over the two days of competition was carried out. Of 285 individual competitors there was a percentage injury rate of 5.26%. The article discusses the injuries and aspects of safety in orienteering. Imagesp236-ap237-ap237-bp238-ap239-ap240-a PMID:7159815

  6. Prosthetic elbow joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1994-01-01

    An artificial, manually positionable elbow joint for use in an upper extremity, above-elbow, prosthetic is described. The prosthesis provides a locking feature that is easily controlled by the wearer. The instant elbow joint is very strong and durable enough to withstand the repeated heavy loadings encountered by a wearer who works in an industrial, construction, farming, or similar environment. The elbow joint of the present invention comprises a turntable, a frame, a forearm, and a locking assembly. The frame generally includes a housing for the locking assembly and two protruding ears. The forearm includes an elongated beam having a cup-shaped cylindrical member at one end and a locking wheel having a plurality of holes along a circular arc on its other end with a central bore for pivotal attachment to the protruding ears of the frame. The locking assembly includes a collar having a central opening with a plurality of internal grooves, a plurality of internal cam members each having a chamfered surface at one end and a V-shaped slot at its other end; an elongated locking pin having a crown wheel with cam surfaces and locking lugs secured thereto; two coiled compression springs; and a flexible filament attached to one end of the elongated locking pin and extending from the locking assembly for extending and retracting the locking pin into the holes in the locking wheel to permit selective adjustment of the forearm relative to the frame. In use, the turntable is affixed to the upper arm part of the prosthetic in the conventional manner, and the cup-shaped cylindrical member on one end of the forearm is affixed to the forearm piece of the prosthetic in the conventional manner. The elbow joint is easily adjusted and locked between maximum flex and extended positions.

  7. 38 CFR 4.73 - Schedule of ratings-muscle injuries.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... injuries of bones, joints, tendons, etc. Rate on limitation of motion, minimum 10 percent. The Foot and Leg...-muscle injuries. 4.73 Section 4.73 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS...—muscle injuries. Note: When evaluating any claim involving muscle injuries resulting in loss of use...

  8. Two Patients with Osteochondral Injury of the Weight-Bearing Portion of the Lateral Femoral Condyle Associated with Lateral Dislocation of the Patella

    PubMed Central

    Inoue, Hiroaki; Atsumi, Satoru; Ichimaru, Shohei; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2014-01-01

    Complications of patellar dislocation include osteochondral injury of the lateral femoral condyle and patella. Most cases of osteochondral injury occur in the anterior region, which is the non-weight-bearing portion of the lateral femoral condyle. We describe two patients with osteochondral injury of the weight-bearing surface of the lateral femoral condyle associated with lateral dislocation of the patella. The patients were 18- and 11-year-old females. Osteochondral injury occurred on the weight-bearing surface distal to the lateral femoral condyle. The presence of a free osteochondral fragment and osteochondral injury of the lateral femoral condyle was confirmed on MRI and reconstruction CT scan. Treatment consisted of osteochondral fragment fixation or microfracture, as well as patellar stabilization. Osteochondral injury was present in the weight-bearing portion of the lateral femoral condyle in both patients, suggesting that the injury was caused by friction between the patella and lateral femoral condyle when the patella was dislocated or reduced at about 90° flexion of the knee joint. These findings indicate that patellar dislocation may occur and osteochondral injury may extend to the weight-bearing portion of the femur even in deep flexion, when the patella is stabilized on the bones of the femoral groove. PMID:25506015

  9. Injuries in elite Taekwondo Poomsae athletes.

    PubMed

    Kazemi, Mohsen; Ingar, Anas; Jaffery, Ali

    2016-12-01

    Poomsae is the only non-contact and no opponent form of Taekwondo. The purpose of this descriptive study was to determine the type and rate of injuries in elite Canadian Poomsae athletes. Strain and joint dysfunction were the most common types of injuries in Poomsae. Lower limb and back were the most common area of injury in females and males respectively. Females with a lower rank in experience level (DAN≤ 3) were more likely to suffer from chronic overuse injuries compared to their male counterparts, who reported more acute injuries. Athletes ≤40 years of age were more prone to acute injuries compared to athletes over 40. As result of reflection on this study a Poomsae Injury Report Form was developed.

  10. Aquatic antagonists: cutaneous sea urchin spine injury.

    PubMed

    Hsieh, Clifford; Aronson, Erica R; Ruiz de Luzuriaga, Arlene M

    2016-11-01

    Injuries from sea urchin spines are commonly seen in coastal regions with high levels of participation in water activities. Although these injuries may seem minor, the consequences vary based on the location of the injury. Sea urchin spine injuries may cause arthritis and synovitis from spines in the joints. Nonjoint injuries have been reported, and dermatologic aspects of sea urchin spine injuries rarely have been discussed. We present a case of a patient with sea urchin spines embedded in the thigh who subsequently developed painful skin nodules. Tissue from the site of the injury demonstrated foreign-body type granulomas. Following the removal of the spines and granulomatous tissue, the patient experienced resolution of the nodules and associated pain. Extraction of sea urchin spines can attenuate the pain and decrease the likelihood of granuloma formation, infection, and long-term sequelae.

  11. Injuries in elite Taekwondo Poomsae athletes

    PubMed Central

    Kazemi, Mohsen; Ingar, Anas; Jaffery, Ali

    2016-01-01

    Poomsae is the only non-contact and no opponent form of Taekwondo. The purpose of this descriptive study was to determine the type and rate of injuries in elite Canadian Poomsae athletes. Strain and joint dysfunction were the most common types of injuries in Poomsae. Lower limb and back were the most common area of injury in females and males respectively. Females with a lower rank in experience level (DAN≤ 3) were more likely to suffer from chronic overuse injuries compared to their male counterparts, who reported more acute injuries. Athletes ≤40 years of age were more prone to acute injuries compared to athletes over 40. As result of reflection on this study a Poomsae Injury Report Form was developed. PMID:28065994

  12. Rehabilitation of spinal cord injuries

    PubMed Central

    Nas, Kemal; Yazmalar, Levent; Şah, Volkan; Aydın, Abdulkadir; Öneş, Kadriye

    2015-01-01

    Spinal cord injury (SCI) is the injury of the spinal cord from the foramen magnum to the cauda equina which occurs as a result of compulsion, incision or contusion. The most common causes of SCI in the world are traffic accidents, gunshot injuries, knife injuries, falls and sports injuries. There is a strong relationship between functional status and whether the injury is complete or not complete, as well as the level of the injury. The results of SCI bring not only damage to independence and physical function, but also include many complications from the injury. Neurogenic bladder and bowel, urinary tract infections, pressure ulcers, orthostatic hypotension, fractures, deep vein thrombosis, spasticity, autonomic dysreflexia, pulmonary and cardiovascular problems, and depressive disorders are frequent complications after SCI. SCI leads to serious disability in the patient resulting in the loss of work, which brings psychosocial and economic problems. The treatment and rehabilitation period is long, expensive and exhausting in SCI. Whether complete or incomplete, SCI rehabilitation is a long process that requires patience and motivation of the patient and relatives. Early rehabilitation is important to prevent joint contractures and the loss of muscle strength, conservation of bone density, and to ensure normal functioning of the respiratory and digestive system. An interdisciplinary approach is essential in rehabilitation in SCI, as in the other types of rehabilitation. The team is led by a physiatrist and consists of the patients’ family, physiotherapist, occupational therapist, dietician, psychologist, speech therapist, social worker and other consultant specialists as necessary. PMID:25621206

  13. Rehabilitation of spinal cord injuries.

    PubMed

    Nas, Kemal; Yazmalar, Levent; Şah, Volkan; Aydın, Abdulkadir; Öneş, Kadriye

    2015-01-18

    Spinal cord injury (SCI) is the injury of the spinal cord from the foramen magnum to the cauda equina which occurs as a result of compulsion, incision or contusion. The most common causes of SCI in the world are traffic accidents, gunshot injuries, knife injuries, falls and sports injuries. There is a strong relationship between functional status and whether the injury is complete or not complete, as well as the level of the injury. The results of SCI bring not only damage to independence and physical function, but also include many complications from the injury. Neurogenic bladder and bowel, urinary tract infections, pressure ulcers, orthostatic hypotension, fractures, deep vein thrombosis, spasticity, autonomic dysreflexia, pulmonary and cardiovascular problems, and depressive disorders are frequent complications after SCI. SCI leads to serious disability in the patient resulting in the loss of work, which brings psychosocial and economic problems. The treatment and rehabilitation period is long, expensive and exhausting in SCI. Whether complete or incomplete, SCI rehabilitation is a long process that requires patience and motivation of the patient and relatives. Early rehabilitation is important to prevent joint contractures and the loss of muscle strength, conservation of bone density, and to ensure normal functioning of the respiratory and digestive system. An interdisciplinary approach is essential in rehabilitation in SCI, as in the other types of rehabilitation. The team is led by a physiatrist and consists of the patients' family, physiotherapist, occupational therapist, dietician, psychologist, speech therapist, social worker and other consultant specialists as necessary.

  14. TH-A-18C-02: An Electrostatic Model for Assessment of Joint Space Morphology in Cone-Beam CT

    SciTech Connect

    Cao, Q; Thawait, G; Gang, G; Zbijewski, W; Riegel, T; Demehri, S; Siewerdsen, J

    2014-06-15

    Purpose: High-resolution cone-beam CT (CBCT) of the extremities presents a potentially valuable basis for image-based biomarkers of arthritis, trauma, and risk of injury. We present a new method for 3D joint space analysis that exploits the high isotropic spatial resolution of CBCT and is sensitive to small changes in disease-related morphology. Methods: The approach uses an “electrostatic” model in which joint surfaces (e.g., distal femur and proximal tibia) are labeled as charge densities between which the electric field is solved by approximation to the Laplace equation. The method yields a unique solution determined by the field lines across the “capacitor” and is hypothesized to be more sensitive than conventional (Sharp) scores and immune to degeneracies that limit simple distance-along-axis or closest-point analysis. The algorithm was validated in CBCT phantom images and applied in two clinical scenarios: osteoarthritis (OA, change in loadbearing tibiofemoral joint space); and assessment of injury risk (correlation of 3D joint space to tibial slope). Results: Joint space maps computed from the electrostatic model were accurate to within the voxel size (0.26 mm). The method highlighted subtle regions of morphological change that would likely be missed by conventional scalar metrics. Regions of subtle cartilage erosion were well quantified, and the method confidently discriminated OA and non-OA cohorts. 3D joint space maps correlated well with tibial slope and provide a new basis for principal component analysis of loadbearing injury risk. Runtime was less than 5 min (235×235×121 voxel subvolume in Matlab). Conclusion: A new method for joint space assessment was reported as a possible image-based biomarker of subtle articular change. The algorithm yields accurate quantitation of the joint in a manner that is robust against operator and patient setup variation. The method shows promising initial results in ongoing trials of CBCT in osteoarthritis

  15. Waterbike injuries.

    PubMed Central

    Jeffery, R S; Caiach, S

    1991-01-01

    Jet skiing is a rapidly growing sport. The craft incorporate safety features and the manufacturers issue detailed safety instructions. Racing is conducted with adequate attention to clothing, safety and insurance. However, casual use is widespread and is sometimes irresponsible. Serious injuries to riders are uncommon: dental and knee injuries are described. A case of renal contusion and a head injury were caused by other riders and two potentially fatal injuries illustrate the risk for other water users. The number of injuries associated with the use of personal watercraft is likely to increase and may be influenced by appropriate organization or regulation. Images Figure 2 Figure 3 Figure 4 PMID:1810620

  16. Abduction dislocation of the knee joint--a case study.

    PubMed

    Wójcik, Krzysztof; Bielecki, Tomasz; Polak, Damian; Skowron, Lukasz

    2013-10-31

    The paper presents a case of untypical, not included in existing classifications, knee joint dislocation in a young man. An MRI scan confirmed a rupture of both cruciate ligaments and damage to the ligamento-capsular complex on the medial side of the knee joint. Two weeks after injury, an arthroscopy was performed with joint lavage followed by repair of the damaged ligamento-capsular complex. A very good functional result was obtained three years after the injury, in spite of the patient not having consented to an elective cruciate ligament reconstruction.

  17. Thermal Protection System with Staggered Joints

    NASA Technical Reports Server (NTRS)

    Simon, Xavier D. (Inventor); Robinson, Michael J. (Inventor); Andrews, Thomas L. (Inventor)

    2014-01-01

    The thermal protection system disclosed herein is suitable for use with a spacecraft such as a reentry module or vehicle, where the spacecraft has a convex surface to be protected. An embodiment of the thermal protection system includes a plurality of heat resistant panels, each having an outer surface configured for exposure to atmosphere, an inner surface opposite the outer surface and configured for attachment to the convex surface of the spacecraft, and a joint edge defined between the outer surface and the inner surface. The joint edges of adjacent ones of the heat resistant panels are configured to mate with each other to form staggered joints that run between the peak of the convex surface and the base section of the convex surface.

  18. An oral absorbent, surface-deacetylated chitin nano-fiber ameliorates renal injury and oxidative stress in 5/6 nephrectomized rats.

    PubMed

    Anraku, Makoto; Tabuchi, Ryo; Ifuku, Shinsuke; Nagae, Tomone; Iohara, Daisuke; Tomida, Hisao; Uekama, Kaneto; Maruyama, Toru; Miyamura, Shigeyuki; Hirayama, Fumitoshi; Otagiri, Masaki

    2017-04-01

    In this study, we report that surface-deacetylated chitin nano-fibers (SDACNFs) are more effective in decreasing renal injury and oxidative stress than deacetylated chitin powder (DAC) in 5/6 nephrectomized rats. An oral administration of low doses of SDACNFs (40mg/kg/day) over a 4 week period resulted in a significant decrease in serum indoxyl sulfate, creatinine and urea nitrogen levels, compared with a similar treatment with DAC or AST-120. The SDACNFs treatment also resulted in an increase in antioxidant potential, compared with that for DAC or AST-120. Immunohistochemical analyses also demonstrated that SDACNFs treated CRF rats showed a decrease in the amount of accumulated 8-OHdG compared with the CRF group. These results suggest that the ingestion of SDCH-NF results in a significant reduction in the levels of pro-oxidants, such as uremic toxins, in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress in the systemic circulation.

  19. Bicycling injuries.

    PubMed

    Silberman, Marc R

    2013-01-01

    Bicycling injuries can be classified into bicycle contact, traumatic, and overuse injuries. Despite the popularity of cycling, there are few scientific studies regarding injuries. Epidemiological studies are difficult to compare due to different methodologies and the diverse population of cyclists studied. There are only three studies conducted on top level professionals. Ninety-four percent of professionals in 1 year have experienced at least one overuse injury. Most overuse injuries are mild with limited time off the bike. The most common site of overuse injury is the knee, and the most common site of traumatic injury is the shoulder, with the clavicle having the most common fracture. Many overuse and bicycle contact ailments are relieved with simple bike adjustments.

  20. High-strength braze joints between copper and steel

    NASA Technical Reports Server (NTRS)

    Kuhn, R. F.

    1967-01-01

    High-strength braze joints between copper and steel are produced by plating the faying surface of the copper with a layer of gold. This reduces porosity in the braze area and strengthens the resultant joint.

  1. [Causes and prevention of typical volleyball injuries].

    PubMed

    Hell, H; Schönle, C

    1985-01-01

    A survey conducted among 224 volleyball players in the German Federal League revealed a high number of serious injuries. The upper ankle joint (55.1% of all serious injuries) and the fingers (22.4%) were most commonly affected. The principal cause of the accidents was a collision with an opponent at the net. There is a close relationship between the player's position, the part he plays in the game and the frequency of injury. Aside from other measures a change of one of the international volleyball rules would represent a suitable method of preventing such injuries.

  2. Injury potential in modern ice hockey.

    PubMed

    Sim, F H; Chao, E Y

    1978-01-01

    The majority of the damaging forces to the soft tissue, bone, and articular joint structures of modern hockey players during the energetic activities involved in the game are attributable to impact action during high-speed motion. In addition, non-contact musculoligamentous injuries are common because of the complex forces that are involved. The injury potential of this sport is assessed indirectly from the force and motion involved. The experimental method of measuring the kinematic motion and the impact forces inherent to the sport are presented. Although hockey is a fast and furious game with high injury potential, fortunately the number of serious injuries is not as great as one might expect.

  3. Neuromodulation by surface electrical stimulation of peripheral nerves for reduction of detrusor overactivity in patients with spinal cord injury: A pilot study

    PubMed Central

    Ojha, Rajdeep; George, Jacob; Chandy, Bobeena R.; Tharion, George; Devasahayam, Suresh R.

    2015-01-01

    Objectives To demonstrate reduction in detrusor overactivity using surface electrical stimulation of posterior tibial nerve (PTN) or dorsal penile nerve (DPN) in patients with spinal cord injury (SCI). Design Patients with SCI with symptoms of urinary urgency/leaks, with cystometrogram (CMG) proven detrusor overactivity were recruited in this study. Ten persons with observable F-wave from tibial nerve were included in the PTN group. Five persons who had F-wave absent but preserved bulbocavernosus reflex were included in the DPN group. Stimulation was given at 20 Hz, 10–40 mA for 20 minutes/session/day for 14 consecutive days. Detrusor overactivity was recorded using CMG on days 1 and 15. Settings Rehabilitation Institute, Department of Physical Medicine and Rehabilitation, Christian Medical College and Hospital, Vellore, TN, India. Participants Patients with SCI. Interventions Surface stimulation of peripheral nerves for reduction of detrusor overactivity. Outcome measures Qualitative analysis using voiding diary data and quantitative analysis using CMG data comparing pre- and post-intervention. Results P value obtained from voiding chart was 0.021 for PTN and 0.062 for DPN. P value obtained from CMG data was not significant in both groups. In one subject, treatment was extended to 4 weeks and further improvement in voiding diary was seen. Conclusions In this pilot study of 15 patients, voiding chart data showed statistically significant improvement following PTN stimulation and trend of improvement following DPN stimulation. However, the CMG data were not statistically significant in this sample population. Further studies with larger, appropriately powered sample size would be helpful to demonstrate the associations of symptoms with CMG data. Trial registration CTRI no.; CTRI/2012/12/003234; CMCH Approval no.: CMC/IRB/6735/2008/12/18. PMID:24621046

  4. Injuries in male versus female soccer players: epidemiology of a nationwide study.

    PubMed

    Mufty, S; Bollars, P; Vanlommel, L; Van Crombrugge, K; Corten, K; Bellemans, J

    2015-06-01

    The aim of this study is to analyse soccer injuries on a national scale over one decade and to compare injury rates by gender. Detailed injury data obtained from the Royal Belgian Football Association from seasons 1999-2000 and 2009-2010 were recorded and gender differences in incidences of injuries, type of injury, affected body part and timing of injury were compared. A significant decrease in injuries from 7.56 to 5.96 injuries per 100 players was seen (p<0.0001). Overall male players sustained more cont usions, fractures, joint dislocations and musculotendinous injuries than female players. Proportionally, females sustained more severe injuries than men (p<0.0001). Significantly more injuries where sustained during competition in both males and females. The number of injuries in male and female soccer players has decreased over the past decade. A higher injury rate was seen in men but proportionally, females sustained more severe injuries.

  5. Injury - kidney and ureter

    MedlinePlus

    Kidney damage; Toxic injury of the kidney; Kidney injury; Traumatic injury of the kidney; Fractured kidney; Inflammatory injury of the kidney; Bruised kidney; Ureteral injury; Pre-renal failure - injury, ...

  6. Constraints influencing sports wheelchair propulsion performance and injury risk

    PubMed Central

    2013-01-01

    The Paralympic Games are the pinnacle of sport for many athletes with a disability. A potential issue for many wheelchair athletes is how to train hard to maximise performance while also reducing the risk of injuries, particularly to the shoulder due to the accumulation of stress placed on this joint during activities of daily living, training and competition. The overall purpose of this narrative review was to use the constraints-led approach of dynamical systems theory to examine how various constraints acting upon the wheelchair-user interface may alter hand rim wheelchair performance during sporting activities, and to a lesser extent, their injury risk. As we found no studies involving Paralympic athletes that have directly utilised the dynamical systems approach to interpret their data, we have used this approach to select some potential constraints and discussed how they may alter wheelchair performance and/or injury risk. Organism constraints examined included player classifications, wheelchair setup, training and intrinsic injury risk factors. Task constraints examined the influence of velocity and types of locomotion (court sports vs racing) in wheelchair propulsion, while environmental constraints focused on forces that tend to oppose motion such as friction and surface inclination. Finally, the ecological validity of the research studies assessing wheelchair propulsion was critiqued prior to recommendations for practice and future research being given. PMID:23557065

  7. Solders in Real Electronic Joints

    NASA Astrophysics Data System (ADS)

    Rudajevová, A.; Dušek, K.

    2014-07-01

    Undercooling and recalescence were studied using the differential scanning calorimetry (DSC) method on real electronic systems. Two solder pastes, Sn62.5Pb36.5Ag1 and Sn96.5Ag3Cu0.5, were used for preparation of electronic joints. Various combinations of these solders and soldering pads with different surface finishes such as Cu, Cu-Ni-Au, Cu-Sn, and Cu-Sn99Cu1 were used. During melting of both pastes, the Sn and Sn99Cu1 surface finishes immediately dissolved in the solder and the Cu surface coating was exposed to the melt. Therefore, practically the same undercooling was found for the Cu, Cu-Sn, and Cu-Sn99Cu1 coatings. The lowest undercooling was found for the Cu-Ni-Au surface finish for both solder pastes. If two separated electronic joints were made on the sample, two separate peaks were found in the DSC signal during solidification. In the sample with only one joint, only one exothermic peak was found. These findings were observed for all paste/surface finish combinations. These data were analyzed, showing that this effect is a consequence of undercooling and recalescence: Latent heat released during solidification of the joint increases the surrounding temperature and influences all the processes taking place.

  8. Optimal management of ulnar collateral ligament injury in baseball pitchers

    PubMed Central

    Hibberd, Elizabeth E; Brown, J Rodney; Hoffer, Joseph T

    2015-01-01

    The ulnar collateral ligament stabilizes the elbow joint from valgus stress associated with the throwing motion. During baseball pitching, this ligament is subjected to tremendous stress and injury if the force on the ulnar collateral ligament during pitching exceeds the physiological limits of the ligament. Injuries to the throwing elbow in baseball pitchers result in significant time loss and typically surgical intervention. The purpose of this paper is to provide a review of current information to sports medicine clinicians on injury epidemiology, injury mechanics, injury risk factors, injury prevention, surgical interventions, nonsurgical interventions, rehabilitation, and return to play outcomes in baseball pitchers of all levels. PMID:26635490

  9. P and S wave tomography of Japan subduction zone from joint inversions of local and teleseismic travel times and surface-wave data

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Zhao, Dapeng

    2016-03-01

    We determined P and S wave velocity tomography of the Japan subduction zone down to a depth of 700 km by conducting joint inversions of a large number of high-quality arrival-time data of local earthquakes and teleseismic events which are newly collected for this study. We also determined 2-D phase-velocity images of fundamental mode Rayleigh waves at periods of 20-150 s beneath Japan and the surrounding oceanic regions using amplitude and phase data of teleseismic Rayleigh waves. A detailed 3-D S-wave tomography of the study region is obtained by jointly inverting S-wave arrival times of local and teleseismic events and the Rayleigh-wave phase-velocity data. Our inversion results reveal the subducting Pacific and Philippine Sea slabs clearly as dipping high-velocity zones from a 1-D starting velocity model. Prominent low-velocity (low-V) anomalies are revealed in the mantle wedge above the slabs and in the mantle below the Pacific slab. The distinct velocity contrasts between the subducting slabs and the surrounding mantle reflect significant lateral variations in temperature as well as water content and/or the degree of partial melting. The low-V anomalies in the mantle wedge are attributed to slab dehydration and corner flows in the mantle wedge. A sheet-like low-V zone is revealed under the Pacific slab beneath NE Japan, which may reflect hot upwelling from the deeper mantle and subduction of a plume-fed asthenosphere as well. Our present results indicate that joint inversions of different seismic data are very effective and important for obtaining robust tomographic images of the crust and mantle.

  10. Joint x-ray

    MedlinePlus

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  11. Knee Kinematics During Non-contact ACL Injury as Determined from Bone Bruise Location

    PubMed Central

    Kim, Sophia Y.; Spritzer, Charles E.; Utturkar, Gangadhar M.; Toth, Alison P.; Garrett, William E.; DeFrate, Louis E.

    2015-01-01

    Background The motions causing non-contact ACL injury remain unclear. Tibiofemoral bone bruises are believed to be the result of joint impact near the time of ACL rupture. The locations and frequencies of these bone bruises have been reported, but there is limited data quantifying knee position and orientation near the time of injury based on these contusions. Hypothesis Knee position and orientation near the time of non-contact ACL injury include extension and anterior tibial translation. Study Design Descriptive Laboratory Study Methods Magnetic resonance (MR) images of eight subjects with non-contact ACL injuries were acquired within one month of injury and subsequently analyzed. All subjects exhibited bruises on both the femur and tibia in both medial and lateral compartments. The outer margins of bone and the bone bruise surfaces were outlined on each image to create a 3D model of each subject’s knee in its position during MR imaging (MRI position). Numerical optimization was used to maximize overlap of the bone bruises on the femur and tibia and predict the position of injury. Flexion angle, valgus orientation, internal tibial rotation, and anterior tibial translation were measured in both the MRI position and the predicted position of injury. Differences in kinematics between the MRI position, which served as an unloaded reference, and the predicted position of injury were compared using paired t-tests. Results Flexion angle was near full extension in both the MRI position and the predicted position of injury (8° versus 12°, p=0.2). Statistically significant increases in valgus orientation (5°, p=0.003), internal tibial rotation (15°, p=0.003), and anterior tibial translation (22mm, p<0.001) were observed in the predicted position of injury relative to the MRI position. Conclusions These results suggest that for the bone bruise pattern studied, landing on an extended knee is high risk for ACL injury. Extension was accompanied by increased anterior

  12. Spacesuit mobility knee joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1979-01-01

    Pressure suit mobility joints are for use in interconnecting adjacent segments of an hermetically sealed spacesuit in which low torques, low leakage and a high degree of reliability are required. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics and includes linkages which restrain the joint from longitudinal distension and includes a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  13. Spacesuit mobility joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1978-01-01

    Joints for use in interconnecting adjacent segments of an hermetically sealed spacesuit which have low torques, low leakage and a high degree of reliability are described. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics. Linkages which restrain the joint from longitudinal distension and a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli are featured. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  14. Stable, Thermally Conductive Fillers for Bolted Joints

    NASA Technical Reports Server (NTRS)

    LeVesque, Raymond J., II; Jones, Cherie A.; Babel, Henry W.

    2003-01-01

    A commercial structural epoxy [Super Koropon (or equivalent)] has been found to be a suitable filler material for bolted joints that are required to have large thermal conductances. The contact area of such a joint can be less than 1 percent of the apparent joint area, the exact value depending on the roughnesses of the mating surfaces. By occupying the valleys between contact peaks, the filler widens the effective cross section for thermal conduction. In comparison with prior thermal joint-filler materials, the present epoxy offers advantages of stability, ease of application, and -- as a byproduct of its stability -- lasting protection against corrosion. Moreover, unlike silicone greases that have been used previously, this epoxy does not migrate to contaminate adjacent surfaces. Because this epoxy in its uncured state wets metal joint surfaces and has low viscosity, it readily flows to fill the gaps between the mating surfaces: these characteristics affect the overall thermal conductance of the joint more than does the bulk thermal conductivity of the epoxy, which is not exceptional. The thermal conductances of metal-to-metal joints containing this epoxy were found to range between 5 and 8 times those of unfilled joints.

  15. Evaluation of two transport aircraft and several ground test vehicle friction measurements obtained for various runway surface types and conditions. A summary of test results from joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1990-01-01

    Tests with specially instrumented NASA Boeing 737 and 727 aircraft together with several different ground friction measuring devices were conducted for a variety of runway surface types and conditions. These tests are part of joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program aimed at obtaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow and ice-covered runway conditions is discussed as well as ground vehicle friction data obtained under similar runway conditions. For a given contaminated runway surface condition, the correlation between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, type and amount of surface contaminant, and ambient temperature are discussed. The effect of surface type on wet friction levels is also evaluated from comparative data collected on grooved and ungrooved concrete and asphalt surfaces.

  16. Environmental injuries.

    PubMed

    Leikin, J B; Aks, S E; Andrews, S; Auerbach, P S; Cooper, M A; Jacobsen, T D; Krenzelok, E P; Shicker, L; Weiner, S L

    1997-12-01

    Environmental injuries and illnesses can happen in home, work, or recreational settings. The variety and severity of these injuries might require the clinician to call on skills from internal medicine, emergency medicine, and toxicology. Diseases of thermoregulation are hypothermia and hyperthermia. In each instance, treatment is based on the need to restore the patient's core temperature to normal and on monitoring for complications. The victim of a fire might suffer inhalation injury in addition to burns, and it is more likely that the inhalation injury will be fatal. Oxygen deprivation and inhalation of irritant or asphyxiant chemicals contribute to injury. Toxic plants can be the source of poisoning emergencies, especially in children. Misinformation and myths that surround common plants can create diagnostic problems (i.e., which plants really are toxic and require emergency measures). Venomous marine organisms can cause a wide range of injury, from cutaneous eruption to fatal envenomation. Most are encountered in a recreational setting, such as water sports, but keepers of home aquariums are subject to stings from venomous fish. Lightning injury can present many diagnostic and treatment dilemmas. An important point in this regard is that lightning injury and high-voltage electrical injury are different in pathology and require different approaches for treatment. A discussion of electrical, chemical, and thermal burns makes such differences apparent.

  17. Paragliding injuries.

    PubMed Central

    Krüger-Franke, M; Siebert, C H; Pförringer, W

    1991-01-01

    Regulations controlling the sport of paragliding were issued in April 1987 by the German Department of Transportation. The growing popularity of this sport has led to a steady increase in the number of associated injuries. This study presents the incidence, localization and degree of injuries associated with paragliding documented in Germany, Austria and Switzerland. The 283 injuries suffered by 218 paragliders were documented in the period 1987-1989: 181 occurred during landing, 28 during starting procedures and nine during flight. The mean patient age was 29.6 years. There were 34.9% spinal injuries, 13.4% upper extremity injuries and 41.3% lower limb injuries. Over half of these injuries were treated surgically and in 54 instances permanent disability remained. In paragliding the lower extremities are at greatest risk of injury during landing. Proper equipment, especially sturdy footwear, exact training in landing techniques as well as improved instruction in procedures during aborted or crash landings is required to reduce the frequency of these injuries. Images p99-a p100-a p100-b p100-c PMID:1751899

  18. Paragliding injuries.

    PubMed

    Krüger-Franke, M; Siebert, C H; Pförringer, W

    1991-06-01

    Regulations controlling the sport of paragliding were issued in April 1987 by the German Department of Transportation. The growing popularity of this sport has led to a steady increase in the number of associated injuries. This study presents the incidence, localization and degree of injuries associated with paragliding documented in Germany, Austria and Switzerland. The 283 injuries suffered by 218 paragliders were documented in the period 1987-1989: 181 occurred during landing, 28 during starting procedures and nine during flight. The mean patient age was 29.6 years. There were 34.9% spinal injuries, 13.4% upper extremity injuries and 41.3% lower limb injuries. Over half of these injuries were treated surgically and in 54 instances permanent disability remained. In paragliding the lower extremities are at greatest risk of injury during landing. Proper equipment, especially sturdy footwear, exact training in landing techniques as well as improved instruction in procedures during aborted or crash landings is required to reduce the frequency of these injuries.

  19. Head Injuries

    MedlinePlus

    ... injury, cerebral contusion, cerebral laceration, coma, head trauma, hematoma, impaired consciousness, postconcussion syndrome, skull fracture, skull penetration, stupor, vegetative state Family Health, Infants ...

  20. Hamstring Injury

    MedlinePlus

    ... result. Hamstring injury risk factors include: Sports participation. Sports that require sprinting or running, or other activities such as dancing that might require extreme stretching, make a hamstring ...

  1. Progress in understanding sheeting joints over the past two centuries

    NASA Astrophysics Data System (ADS)

    Martel, Stephen J.

    2017-01-01

    Sheeting joints share many geometric, textural, and kinematic features with other joints, but differ in that they are (a) discernibly curved, and (b) open near to and subparallel to the topographic surface. Where sheeting joints are geologically young, the surface-parallel compressive stresses are large, typically several MPa or greater. Sheeting joints typically are best developed beneath domes, ridges, and saddles. They also are reported beneath valleys or bowls. A mechanism that accounts for these associations has been sought for more than a century: the commonly subscribed explanation of erosion of overburden, by itself, is inadequate. Principles of fracture mechanics, together with the mechanical effects of a curved topographic surface experiencing a surface-parallel compression, provide a framework that accounts for the cardinal characteristics of sheeting joints. A compressive stress parallel to a convex topographic surface induces a tension perpendicular to the surface at shallow depths. In some cases, this combination alone can overcome the weight of overburden to open sheeting joints. Plausible distributions of water pressure in sheeting joints would help open and drive sheeting joints beneath valleys, saddles, and bowls. Thermal stresses help sheeting joints develop very near the ground surface. Sheeting joints thus appear to reflect an intricate fracture process primarily involving the shape, slope, and scale of the topography; the regional horizontal stresses; the effect of gravity; and groundwater pressure. Understanding how sheeting joints evolve in three dimensions through time remains an outstanding challenge and would illuminate their effect on landscapes, slope stability, and fluid flow.

  2. Osteophyte formation after ACL rupture in mice is associated with joint restabilization and loss of range of motion.

    PubMed

    Hsia, Allison W; Anderson, Matthew J; Heffner, Mollie A; Lagmay, Earl P; Zavodovskaya, Regina; Christiansen, Blaine A

    2016-03-31

    Osteophytes are a typical radiographic finding during osteoarthritis (OA). Osteophytes are thought to form in response to joint instability, however the time course of osteophyte formation and joint stabilization following joint injury is not well understood. In this study, we investigated the time course of osteophyte formation and joint function following non-invasive knee injury in mice. We hypothesized that initial joint instability following knee injury would initiate osteophyte formation, which would in turn restabilize the joint and reduce range of motion (ROM). Mice were subjected to non-invasive anterior cruciate ligament (ACL) rupture. Anterior-posterior (AP) joint laxity, ROM, and chondro/osteophyte formation were measured immediately after injury, and 2, 4, 6, and 8 weeks post-injury. Chondrophyte areas at each time point were measured with histology, while mineralized osteophyte volume was determined using micro-computed tomography. Immediately after ACL rupture, AP joint laxity was increased 2-fold, while ROM was increased 11.7%. Chondrophytes appeared by 2 weeks post-injury, corresponding with a decrease in AP joint laxity and ROM. By 8 weeks post-injury, considerable osteophyte formation was observed around the joint, AP joint laxity returned to control levels, and joint ROM decreased to 61% of control values. These data support a role for chondro/osteophytes in joint restabilization after injury, and provide crucial insight into the time course and pathology of joint degeneration during OA development in the mouse. Statement of Clinical Significance: Results from this study increase understanding of conditions leading to osteophyte formation. This article is protected by copyright. All rights reserved.

  3. Dissociative Binding of Carboxylic Acid Ligand on Nanoceria Surface in Aqueous Solution: A Joint in Situ Spectroscopic Characterization and First-Principles Study

    SciTech Connect

    Lu, Zhou; Karakoti, Ajay S.; Velarde Ruiz Esparza, Luis A.; Wang, Weina; Yang, Ping; Thevuthasan, Suntharampillai; Wang, Hongfei

    2013-11-21

    Carboxylic acid is a common ligand anchoring group to functionalize nanoparticle surfaces. Its binding structures and mechanisms as a function of the oxidation states of metal oxide nanoparticle surfaces are not well characterized experimentally. We present an in situ sum frequency generation vibrational spectroscopy (SFG-VS) study on the binding of deuterated acetic acid on ceria nanoparticles in the aqueous solution. In the SFG experiment, ceria nanoparticles were deposited on the flat surface of a CaF2 hemisphere in contact with acetic acid solutions. While the ceria nanoparticle deprotonated the acetic acid, the CaF2 surface could not. Thus, the binding of the deprotonated acetic acid on ceria can be selectively probed. SFG spectra revealed that the binding modes of the carboxylate group depend on the oxidation states of the ceria surfaces. SFG polarization analysis suggested that the bidentate chelating and bridging binding modes co-exist on the reduced ceria surfaces, while the oxidized ceria surfaces are dominated by the bidentate bridging mode. The direct spectroscopic evidence helps to clarify the binding structures and mechanisms on the ceria nanoparticles. Furthermore, the middle-infrared (IR) transparent CaF2 and its chemical inertness make CaF2 and similar substrate materials good candidates for direct SFG-VS measurement of nanoparticle surface reactions and binding chem-istry.

  4. An unusual presentation of whiplash injury: long thoracic and spinal accessory nerve injury

    PubMed Central

    Omar, N.; Srinivasan, M. S.

    2007-01-01

    Whiplash injuries from motor vehicle accidents are very common. The usual presentation and course of this condition normally results in resolution of symptoms within a few weeks. Brachial plexus traction injuries without any bone or joint lesion of the cervical spine have been reported before. We report a case where a gentleman was involved in a rear end vehicle collision, sustained a whiplash injury and was later found to have a long thoracic nerve palsy and spinal accessory nerve palsy. Although isolated injuries of both nerves following a whiplash injury have been reported, combined injury of the two nerves following a whiplash injury is very uncommon and is being reported for the first time. PMID:17587067

  5. Social communication in young children with traumatic brain injury: relations with corpus callosum morphometry.

    PubMed

    Ewing-Cobbs, Linda; Prasad, Mary R; Swank, Paul; Kramer, Larry; Mendez, Donna; Treble, Amery; Payne, Christa; Bachevalier, Jocelyne

    2012-05-01

    The purpose of the present investigation was to characterize the relations of specific social communication behaviors, including joint attention, gestures, and verbalization, with surface area of midsagittal corpus callosum (CC) subregions in children who sustained traumatic brain injury (TBI) before 7 years of age. Participants sustained mild (n=10) or moderate-severe (n=26) noninflicted TBI. The mean age at injury was 33.6 months; mean age at MRI was 44.4 months. The CC was divided into seven subregions. Relative to young children with mild TBI, those with moderate-severe TBI had smaller surface area of the isthmus. A semi-structured sequence of social interactions between the child and an examiner was videotaped and coded for specific social initiation and response behaviors. Social responses were similar across severity groups. Even though the complexity of their language was similar, children with moderate-severe TBI used more gestures than those with mild TBI to initiate social overtures; this may indicate a developmental lag or deficit as the use of gestural communication typically diminishes after age 2. After controlling for age at scan and for total brain volume, the correlation of social interaction response and initiation scores with the midsagittal surface area of the CC regions was examined. For the total group, responding to a social overture using joint attention was significantly and positively correlated with surface area of all regions, except the rostrum. Initiating joint attention was specifically and negatively correlated with surface area of the anterior midbody. Use of gestures to initiate a social interaction correlated significantly and positively with surface area of the anterior and posterior midbody. Social response and initiation behaviors were selectively related to regional callosal surface areas in young children with TBI. Specific brainbehavior relations indicate early regional specialization of anterior and posterior CC for social

  6. Self-reported load carriage injuries of military soldiers.

    PubMed

    Orr, Robin Marc; Coyle, Julia; Johnston, Venerina; Pope, Rodney

    2016-01-13

    The aim of this study was to investigate whether occupational load carriage constitutes a significant source of injury to military soldiers. An online survey was sent to soldiers serving in specific Australian Army Corps known to experience the greatest occupational exposure to load carriage. Of the 338 respondents, 34% sustained at least one load carriage injury. Fifty-two per cent of those injured during initial training reported sustaining an additional load carriage injury. The majority of injuries (61%) were to the lower limbs with bones and joints the most frequently injured body structures (39%). Endurance marching (continuous marching as part of a physical training session) was the activity accounting for most (38%) injuries. Occupational load carriage is associated with military soldier injuries and, once injured, soldiers are at a high risk of future load carriage injury. The bodily sites and nature of self-reported injuries in this study are akin to those of formally reported injuries and those of other militaries.

  7. Knee ligament injury during lateral impact.

    PubMed

    Hearon, B F; Brinkley, J W; Raddin, J H; Fleming, B W

    1985-01-01

    A volunteer woman subject incurred injury to her right knee consisting of a torn anterior cruciate ligament and stretched medial collateral ligament during a lateral (+Gy) impact test. Similar injury has not been reported in the English-language literature an accidental sideward automotive crashes or lateral impact experimentation involving humans. The primary mechanism which produced this injury was external tibial rotation on the femur with the knee flexed. The factors contributing to the injury included extraordinarily forceful leg bracing by the subject, her knee joint laxity or hypermobility, and the absence of side supports to limit lower extremity flailing during the impact response. In future lateral impact tests, women subjects should be used with caution and any subject with abnormal joint mobility should be excluded from participation.

  8. Chondral Injury in Patellofemoral Instability

    PubMed Central

    Lustig, Sébastien; Servien, Elvire; Neyret, Philippe

    2014-01-01

    Objective: Patellofemoral instability is common and affects a predominantly young age group. Chondral injury occurs in up to 95%, and includes osteochondral fractures and loose bodies acutely and secondary degenerative changes in recurrent cases. Biomechanical abnormalities, such as trochlear dysplasia, patella alta, and increased tibial tuberosity-trochlear groove distance, predispose to both recurrent dislocations and patellofemoral arthrosis. Design: In this article, we review the mechanisms of chondral injury in patellofemoral instability, diagnostic modalities, the distribution of lesions seen in acute and episodic dislocation, and treatments for articular cartilage lesions of the patellofemoral joint. Results: Little specific evidence exists for cartilage treatments in patellofemoral instability. In general, the results of reparative and restorative procedures in the patellofemoral joint are inferior to those observed in other compartments of the knee. Conclusion: Given the increased severity of chondral lesions and progression to osteoarthritis seen with recurrent dislocations, careful consideration should be given to early stabilisation in patients with predisposing factors. PMID:26069693

  9. Head injuries.

    PubMed

    Yanko, J

    1984-08-01

    In summary, the broad term "head injury" represents a large variety of more specific injuries. In order to anticipate and plan appropriate patient care, nurses need information regarding the cause of injury, the impact site, and the patient's clinical course in addition to current assessment findings. The nurse must also anticipate sequelae from secondary brain injury due to hypoxia, edema, increased intracranial pressure, changes in regional blood flows, or hypovolemic shock due to internal bleeding in another body system or cavity. The head-injured patient is a complex patient requiring intensive nursing care, observation, and assessment. By incorporating knowledge of the mechanisms of injury into nursing observations and assessments, nurses can provide more effective nursing interventions.

  10. Functional anatomy of the temporomandibular joint (I).

    PubMed

    Sava, Anca; Scutariu, Mihaela Monica

    2012-01-01

    Jaw movement is analyzed as the action between two rigid components jointed together in a particular way, the movable mandible against the stabilized cranium. Jaw articulation distinguishes form most other synovial joints of the body by the coincidence of certain characteristic features. Its articular surfaces are not covered by hyaline cartilage as elsewhere. The two jointed components carry teeth the shape, position and occlusion of which having a unique influence on specific positions and movements within the joint. A fibrocartilaginous disc is interposed between upper and lower articular surfaces; this disc compensates for the incongruities in opposing parts and allows sliding, pivoting, and rotating movements between the bony components. These are the reasons for our review of the functional anatomy of the temporomandibular joint.

  11. Constitutive Modelling of Joints under Cyclic Loading. Part 1. Modelling and Testing of Idealized Rock Joints

    DTIC Science & Technology

    1988-07-31

    Crawford and Curran (1981) developed a direct-shear device to examine the effect of shear rate on the shear resistance of smooth artificial joints in dif... Artificial rock joint surfaces were prepared by casting concrete against a structured surface. The structured surface had a "sawtooth" shaped pattern...parameter n, and the constants a and b in the growth function must be determined for the reverse pass. The value of y for the reverse pass is = womb 167

  12. Optimized Bolted Joint

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.; Bunin, B. L.; Watts, D. J.

    1986-01-01

    Computer technique aids joint optimization. Load-sharing between fasteners in multirow bolted composite joints computed by nonlinear-analysis computer program. Input to analysis was load-deflection data from 180 specimens tested as part of program to develop technology of structural joints for advanced transport aircraft. Bolt design optimization technique applicable to major joints in composite materials for primary and secondary structures and generally applicable for metal joints as well.

  13. Mild Traumatic Brain Injury

    MedlinePlus

    ... Questions Glossary Contact Us Visitor Feedback mild Traumatic Brain Injury mild Traumatic Brain Injury VIDEO STORIES What is TBI Measuring Severity ... most common deployment injuries is a mild Traumatic Brain Injury (TBI). A mild TBI is an injury ...

  14. Joint surface reconstruction and 4D deformation estimation from sparse data and prior knowledge for marker-less Respiratory motion tracking

    SciTech Connect

    Berkels, Benjamin; Rumpf, Martin; Bauer, Sebastian; Ettl, Svenja; Arold, Oliver; Hornegger, Joachim

    2013-09-15

    Purpose: The intraprocedural tracking of respiratory motion has the potential to substantially improve image-guided diagnosis and interventions. The authors have developed a sparse-to-dense registration approach that is capable of recovering the patient's external 3D body surface and estimating a 4D (3D + time) surface motion field from sparse sampling data and patient-specific prior shape knowledge.Methods: The system utilizes an emerging marker-less and laser-based active triangulation (AT) sensor that delivers sparse but highly accurate 3D measurements in real-time. These sparse position measurements are registered with a dense reference surface extracted from planning data. Thereby a dense displacement field is recovered, which describes the spatio-temporal 4D deformation of the complete patient body surface, depending on the type and state of respiration. It yields both a reconstruction of the instantaneous patient shape and a high-dimensional respiratory surrogate for respiratory motion tracking. The method is validated on a 4D CT respiration phantom and evaluated on both real data from an AT prototype and synthetic data sampled from dense surface scans acquired with a structured-light scanner.Results: In the experiments, the authors estimated surface motion fields with the proposed algorithm on 256 datasets from 16 subjects and in different respiration states, achieving a mean surface reconstruction accuracy of ±0.23 mm with respect to ground truth data—down from a mean initial surface mismatch of 5.66 mm. The 95th percentile of the local residual mesh-to-mesh distance after registration did not exceed 1.17 mm for any subject. On average, the total runtime of our proof of concept CPU implementation is 2.3 s per frame, outperforming related work substantially.Conclusions: In external beam radiation therapy, the approach holds potential for patient monitoring during treatment using the reconstructed surface, and for motion-compensated dose delivery using

  15. GSB knee joint: a further possibility, principle, results.

    PubMed

    Gschwend, N

    1978-05-01

    The GSB Knee joint is a nonconstrained hinge joint, which combines the advantages of the so-called condylar or surface prosthesis with those of the constrained hinge joints. This report is of observations on the results and complications in 150 arthroplasties performed over a 5 year period.

  16. Ankle Joint Angle and Lower Leg Musculotendinous Unit Responses to Cryotherapy.

    PubMed

    Akehi, Kazuma; Long, Blaine C; Warren, Aric J; Goad, Carla L

    2016-09-01

    Akehi, K, Long, BC, Warren, AJ, and Goad, CL. Ankle joint angle and lower leg musculotendinous unit responses to cryotherapy. J Strength Cond Res 30(9): 2482-2492, 2016-The use of cold application has been debated for its influence on joint range of motion (ROM) and stiffness. The purpose of this study was to determine whether a 30-minute ice bag application to the plantarflexor muscles or ankle influences passive ankle dorsiflexion ROM and lower leg musculotendinous stiffness (MTS). Thirty-five recreationally active college-aged individuals with no history of lower leg injury 6 months before data collection volunteered. On each testing day, we measured maximum passive ankle dorsiflexion ROM (°) and plantarflexor torque (N·m) on an isokinetic dynamometer to calculate the passive plantarflexor MTS (N·m per degree) at 4 joint angles before, during, and after a treatment. Surface electromyography amplitudes (μV), and skin surface and ambient air temperature (°C) were also measured. Subjects received an ice bag to the posterior lower leg, ankle joint, or nothing for 30 minutes in different days. Ice bag application to the lower leg and ankle did not influence passive ROM (F(12,396) = 0.67, p = 0.78). Passive torque increased after ice bag application to the lower leg (F(12,396) = 2.21, p = 0.011). Passive MTS at the initial joint angle increased after ice bag application to the lower leg (F(12,396) = 2.14, p = 0.014) but not at the other joint angles (p > 0.05). Surface electromyography amplitudes for gastrocnemius and soleus muscles increased after ice application to the lower leg (F(2,66) = 5.61, p = 0.006; F(12,396) = 3.60, p < 0.001). Ice bag application to the lower leg and ankle joint does not alter passive dorsiflexion ROM but increases passive ankle plantarflexor torque in addition to passive ankle plantarflexor MTS at the initial joint angle.

  17. Rotational stiffness of American football shoes affects ankle biomechanics and injury severity.

    PubMed

    Button, Keith D; Braman, Jerrod E; Davison, Mark A; Wei, Feng; Schaeffer, Maureen C; Haut, Roger C

    2015-06-01

    While previous studies have investigated the effect of shoe-surface interaction on injury risk, few studies have examined the effect of rotational stiffness of the shoe. The hypothesis of the current study was that ankles externally rotated to failure in shoes with low rotational stiffness would allow more talus eversion than those in shoes with a higher rotational stiffness, resulting in less severe injury. Twelve (six pairs) cadaver lower extremities were externally rotated to gross failure while positioned in 20 deg of pre-eversion and 20 deg of predorsiflexion by fixing the distal end of the foot, axially loading the proximal tibia, and internally rotating the tibia. One ankle in each pair was constrained by an American football shoe with a stiff upper, while the other was constrained by an American football shoe with a flexible upper. Experimental bone motions were input into specimen-specific computational models to examine levels of ligament elongation to help understand mechanisms of ankle joint failure. Ankles in flexible shoes allowed 6.7±2.4 deg of talus eversion during rotation, significantly greater than the 1.7±1.0 deg for ankles in stiff shoes (p = 0.01). The significantly greater eversion in flexible shoes was potentially due to a more natural response of the ankle during rotation, possibly affecting the injuries that were produced. All ankles failed by either medial ankle injury or syndesmotic injury, or a combination of both. Complex (more than one ligament or bone) injuries were noted in 4 of 6 ankles in stiff shoes and 1 of 6 ankles in flexible shoes. Ligament elongations from the computational model validated the experimental injury data. The current study suggested flexibility (or rotational stiffness) of the shoe may play an important role in both the severity of ankle injuries for athletes.

  18. Fetlock joint kinematics differ with age in Thoroughbred [was thoroughbred] racehorses.

    PubMed

    Butcher, Michael T; Ashley-Ross, M A

    2002-05-01

    Fetlock joint kinematics during galloping in 2-, 3-, 4-, and 5-year-old Thoroughbreds in race training were quantified to determine if differences due to age could account for the observation that 2-year old Thoroughbred racehorses incur a high number of injuries to the bones and soft tissues in the distal forelimbs during training and at the outset of racing. Twelve Thoroughbred racehorses were videotaped in the sagittal plane at 250 frames/s during their daily galloping workout on a 7/8 mile sand-surface training track. Four galloping strides were recorded for each horse and subsequently digitized to determine fetlock joint angles of the leading forelimb during the limb support period of a stride. Four kinematic variables were measured from each stride's angular profile: angle of fetlock joint dorsi-flexion at mid-stance, negative angular velocity, positive angular velocity and time from hoof impact to mid-stance phase of limb support. The 2-year old Thoroughbreds had significantly quicker rates of dorsi-flexion of their fetlock joints than 3- (p=0.01), 4- (p=0.01), and 5-year old (p<0.01) Thoroughbreds following impact of the leading forelimb during moderate galloping (avg. 14 m/s). Higher rates of dorsi-flexion in young Thoroughbreds may reflect immaturity (lack of stiffness) of the suspensory apparatus tissues.

  19. Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction

    PubMed Central

    Shim, Jae-Kwang; Choi, Ho-Suk; Shin, Jun-Ho

    2015-01-01

    [Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period. PMID:26834316

  20. Joint inversion of receiver functions and surface waves with enhanced preconditioning on densely distributed CNDSN stations: Crustal and upper mantle structure beneath China

    NASA Astrophysics Data System (ADS)

    Chen, Youlin; Niu, Fenglin

    2016-02-01

    We present shear wave velocity structure beneath China by joint modeling of teleseismic receiver function and Rayleigh wave group velocity dispersion data observed at +1000 permanent broadband seismic stations in the Chinese National Digital Seismic Network (CNDSN). A ray-parameter-based stacking method is employed to minimize artifacts in stacking receiver functions from different sources. The Rayleigh wave dispersion curve is extracted from group velocity tomographic models at all applicable periods. Enhanced preconditions are applied on the linearized iterative inversion to regularize and balance multiple types of data. The velocity profile inversion at each station starts from an initial model derived from sediments, crustal thickness, Vp/Vs ratio and Pn/Sn models. This multistep approach not only reduces uncertainty and nonuniqueness of the velocity inversion but also efficiently fills information gap in each data set. We then generate a 3-D S velocity model by combining and smoothing all the 1-D models. The obtained 3-D model reveals crustal and upper mantle velocity structures that are well correlated with tectonic features of China, for example, our model shows a clear east-west bimodal distribution at 35 km deep, low velocity in the crust beneath central and eastern Tibetan plateau, and sedimentary structure in major cratons and basins. Our model is consistent with existing tomographic models in large scale but provides more structural details in regional and local scales.

  1. 43 CFR 11.62 - Injury determination phase-injury definition.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... definitions provided in this section for surface water, ground water, air, geologic, and biological resources... this section to make a determination of injury. (b) Surface water resources. (1) An injury to a surface water resource has resulted from the discharge of oil or release of a hazardous substance if one or...

  2. Shoulder injuries from attacking motion

    NASA Astrophysics Data System (ADS)

    Yanagi, Shigeru; Nishimura, Tetsu; Itoh, Masaru; Wada, Yuhei; Watanabe, Naoki

    1997-03-01

    Sports injuries have bothered professional players. Although many medical doctors try to treat injured players, to prevent sports injuries is more important. Hence, it is required to clear a kinematic mechanism of the sport injuries. A shoulder of volleyball attacker or baseball pitcher is often inured by playing motion. The injuries are mainly caused at the end of long head tendon, which is located in the upper side of scapula. Generally, a muscle and tendon have enough strength against tensile force, however, it seems that they are sometimes defeated by the lateral force. It is imagined that the effect of the lateral force has a possibility of injuring the tendon. If we find the influence of the lateral force on the injured portion, the mechanism of injuries must be cleared. In our research, volleyball attacking motion is taken by high speed video cameras. We analyze the motion as links system and obtain an acceleration of an arm and a shoulder from video image data. The generated force at a shoulder joint is calculated and resolved into the lateral and longitudinal forces. Our final goal is to discuss a possibility that the lateral force causes the injuries.

  3. Physical examination of the patellofemoral joint.

    PubMed

    Lester, Jonathan D; Watson, Jonathan N; Hutchinson, Mark R

    2014-07-01

    Examination of the patellofemoral joint can prove to be challenging. Although certain acute injuries such as patella fracture or tendon rupture can be diagnosed quickly, more chronic injuries such as patellar subluxation and patellofemoral pain syndrome are more difficult to diagnose because of the subtlety of the examination findings. The source of the problem can also vary, and must be identified to direct treatment. Adding to the complexity is that other structures around the knee may present with anterior knee pain and can be mistaken for patellofemoral disorder, which is why the patellofemoral examination should be performed in the context of a complete knee examination. For all of these reasons, performing a thorough and systematic examination of the patellofemoral joint can lead to optimal outcomes for patients.

  4. The effect of stem material and surface treatment on the torsional stability at the metal-cement interface of upper limb joint replacement systems.

    PubMed

    Hosein, Yara K; King, Graham J W; Dunning, Cynthia E

    2014-08-01

    Stem surface treatment and material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome stems with varying surface treatments in vitro. Thirty implant stems of circular cross-section (Ø = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.

  5. Sports Injuries

    MedlinePlus

    ... Because of its complex structure and weight-bearing capacity, the knee is a commonly injured joint. Lateral ... become swollen, they can fill the compartment to capacity, causing interference with nerves and blood vessels as ...

  6. A Historical Perspective on the Essex-Lopresti Injury

    PubMed Central

    McGlinn, Evan P.; Sebastin, Sandeep J.; Chung, Kevin C.

    2014-01-01

    An Essex-Lopresti injury is a fracture of the radial head with concomitant dislocation of the distal radioulnar joint and rupture of the interosseous membrane. Poor outcomes have been associated with this rare injury if the dislocation of the distal radioulnar joint is missed in the acute setting. This injury is named after the British orthopedic surgeon Peter Essex-Lopresti, who made a number of important observations about this injury in 1951. Peter Essex-Lopresti was a promising young surgeon, and his untimely death at the age of 35 brought an early end to a remarkable career. This article investigates the evolution of treatment for this injury and sheds light on the life of the surgeon for whom the injury is named. PMID:23890499

  7. [External femorotibial transfixation in femoral fracture with joint involvement in a child].

    PubMed

    Nounla, J; Bennek, J; Bühligen, U; Rolle, U

    2001-07-01

    Long bone fractures combined with joint injuries run a high risk of destabilising the articulations. Remaining joints incongruence can lead to early arthosis especially in cases of severe injuries or not achieved anatomical reduction. A number of osteosynthesis methods are available for anatomical repair of the articular facet. This report presents a seven years old boy with an open comminuted fracture of the distal femur and consecutive joint instability, treated with a Transfixation (Orthofix) of the knee joint. The functional results suggest this method as an alternative treatment.

  8. Decomposing Large Inverse Problems with an Augmented Lagrangian Approach: Application to Joint Inversion of Body-Wave Travel Times and Surface-Wave Dispersion Measurements

    NASA Astrophysics Data System (ADS)

    Reiter, D. T.; Rodi, W. L.

    2015-12-01

    Constructing 3D Earth models through the joint inversion of large geophysical data sets presents numerous theoretical and practical challenges, especially when diverse types of data and model parameters are involved. Among the challenges are the computational complexity associated with large data and model vectors and the need to unify differing model parameterizations, forward modeling methods and regularization schemes within a common inversion framework. The challenges can be addressed in part by decomposing the inverse problem into smaller, simpler inverse problems that can be solved separately, providing one knows how to merge the separate inversion results into an optimal solution of the full problem. We have formulated an approach to the decomposition of large inverse problems based on the augmented Lagrangian technique from optimization theory. As commonly done, we define a solution to the full inverse problem as the Earth model minimizing an objective function motivated, for example, by a Bayesian inference formulation. Our decomposition approach recasts the minimization problem equivalently as the minimization of component objective functions, corresponding to specified data subsets, subject to the constraints that the minimizing models be equal. A standard optimization algorithm solves the resulting constrained minimization problems by alternating between the separate solution of the component problems and the updating of Lagrange multipliers that serve to steer the individual solution models toward a common model solving the full problem. We are applying our inversion method to the reconstruction of the·crust and upper-mantle seismic velocity structure across Eurasia.· Data for the inversion comprise a large set of P and S body-wave travel times·and fundamental and first-higher mode Rayleigh-wave group velocities.

  9. Electrical injury

    MedlinePlus

    ... damage, especially to the heart, muscles, or brain. Electric current can cause injury in three ways: Cardiac arrest ... How long you were in contact with the electricity How the electricity moved through your body Your ...

  10. Testicular Injuries

    MedlinePlus

    ... Also, the location of the testicles makes them prime targets to be accidentally struck on the playing ... you might also feel nauseated for a short time. If it's a minor testicular injury, the pain ...

  11. Inhalation Injuries

    MedlinePlus

    ... devastating types of trauma resulting from exposure to fire and smoke. PREVENT you and your loved ones! ... people die annually in the United States from fire injuries. • Over half of these deaths result from ...

  12. Birth Injury

    MedlinePlus

    ... cesarean delivery may be done in certain circumstances. Did You Know... Serious birth injuries are now quite ... are typically not needed. Resources In This Article Did You Know 1 Did You Know... Sidebar 1 ...

  13. Ear Injury

    MedlinePlus

    ... doctors usually give an antibiotic to prevent infection. Did You Know... If left untreated, a swollen, bruised ... can be corrected surgically. Resources In This Article Did You Know 1 Did You Know... Facial Injuries ...

  14. Lightning Injuries

    MedlinePlus

    ... cause internal burns than electrical injuries from generated electricity. However, it can kill a person by instantaneously ... water do not attract lightning but easily transmit electricity once they are hit. Electricity from lightning can ...

  15. Spinal injury

    MedlinePlus

    ... and drive. Do not dive into pools, lakes, rivers, and other bodies of water, particularly if you cannot determine the depth of the ... Central nervous system Spinal cord injury Spinal anatomy Two person roll - ...

  16. Cheerleading injuries: epidemiology and recommendations for prevention.

    PubMed

    LaBella, Cynthia R; Mjaanes, Jeffrey

    2012-11-01

    Over the last 30 years, cheerleading has increased dramatically in popularity and has evolved from leading the crowd in cheers at sporting events into a competitive, year-round sport involving complex acrobatic stunts and tumbling. Consequently, cheerleading injuries have steadily increased over the years in both number and severity. Sprains and strains to the lower extremities are the most common injuries. Although the overall injury rate remains relatively low, cheerleading has accounted for approximately 66% of all catastrophic injuries in high school girl athletes over the past 25 years. Risk factors for injuries in cheerleading include higher BMI, previous injury, cheering on harder surfaces, performing stunts, and supervision by a coach with low level of training and experience. This policy statement describes the epidemiology of cheerleading injuries and provides recommendations for injury prevention.

  17. Electric injury, Part II: Specific injuries.

    PubMed

    Fish, R M

    2000-01-01

    Electric injury can cause disruption of cardiac rhythm and breathing, burns, fractures, dislocations, rhabdomyolysis, eye and ear injury, oral and gastrointestinal injury, vascular damage, disseminated intravascular coagulation, peripheral and spinal cord injury, and Reflex Sympathetic Dystrophy. Secondary trauma from falls, fires, flying debris, and inhalation injury can complicate the clinical picture. Diagnostic and treatment considerations for electric injuries are described in this article, which is the second part of a three-part series on electric injuries.

  18. Exercise-induced metacarpophalangeal joint adaptation in the Thoroughbred racehorse.

    PubMed

    Muir, P; Peterson, A L; Sample, S J; Scollay, M C; Markel, M D; Kalscheur, V L

    2008-12-01

    Repetitive bone injury and development of stress fracture is a common problem in humans and animals. The Thoroughbred racehorse is a model in which adaptive failure and associated development of stress fracture is common. We performed a histologic study of the distal end of the third metacarpal bone in two groups of horses: young Thoroughbreds that were actively racing (n = 10) and a group of non-athletic horses (n = 8). The purpose of this study was to determine whether development of articular microcracks was associated with specific alterations to subchondral plate osteocytes. Morphometric measurements were made in five regions of the joint surface: lateral condyle, lateral condylar groove, sagittal ridge, medial condylar groove, and medial condyle. The following variables were quantified: hyaline cartilage width; calcified cartilage width; the number of tidemarks; microcrack density at the articular surface; blood vessel density entering articular cartilage; the presence of atypical bone matrix in the subchondral plate; bone volume fraction; and osteocyte density. Adaptation of articular cartilage was similar in both groups of horses. Vascularization of articular cartilage was increased in the group of non-athletic horses. Microcracks, which typically had an oblique orientation to the joint surface, were co-localized with blood vessels, and resorption spaces. Microcracking was increased in the condylar grooves of athletic horses compared with the other joint regions and was also increased compared with the condylar groove regions of non-athletic horses. Coalescence of microcracks also led to development of an intracortical articular condylar stress fracture in some joints and targeted remodeling of affected subchondral plate. The subchondral plate of the condyles in athletic horses was sclerotic, and contained atypically stained bone matrix with increased numbers of osteocytes with atypical morphology. However, osteocyte numbers were not significantly different

  19. Modeling of Human Joint Structures.

    DTIC Science & Technology

    1982-09-01

    Radial Lateral " epicondyle Olecranon Radius Ulna Figure 3. Lateral aspect of the right elbow joint. -17- Annular Ligament This strong band encircles... elbow joint, knee joint, human joints, shoulder joint, ankle joint, joint models, hip joint, ligaments. 20. ABSTRACT (Continue on reverse side If...ligaments. -A rather extended discussion of the articulations and anatomical descriptions of the elbow , shoulder, hip, knee and ankle joints are

  20. The Waist Width of Skis Influences the Kinematics of the Knee Joint in Alpine Skiing.

    PubMed

    Zorko, Martin; Nemec, Bojan; Babič, Jan; Lešnik, Blaz; Supej, Matej

    2015-09-01

    Recently alpine skis with a wider waist width, which medially shifts the contact between the ski edge and the snow while turning, have appeared on the market. The aim of this study was to determine the knee joint kinematics during turning while using skis of different waist widths (65mm, 88mm, 110mm). Six highly skilled skiers performed ten turns on a predefined course (similar to a giant slalom course). The relation of femur and tibia in the sagital, frontal and coronal planes was captured by using an inertial motion capture suit, and Global Navigation Satellite System was used to determine the skiers' trajectories. With respect of the outer ski the knee joint flexion, internal rotation and abduction significantly decreased with the increase of the ski waist width for the greatest part of the ski turn. The greatest abduction with the narrow ski and the greatest external rotation (lowest internal rotation) with the wide ski are probably the reflection of two different strategies of coping the biomechanical requirements in the ski turn. These changes in knee kinematics were most probably due to an active adaptation of the skier to the changed biomechanical conditions using wider skis. The results indicated that using skis with large waist widths on hard, frozen surfaces could bring the knee joint unfavorably closer to the end of the range of motion in transversal and frontal planes as well as potentially increasing the risk of degenerative knee injuries. Key pointsThe change in the skis' waist width caused a change in the knee joint movement strategies, which had a tendency to adapt the skier to different biomechanical conditions.The use of wider skis or, in particular, skis with a large waist width, on a hard or frozen surface, could unfavourably bring the knee joint closer to the end of range of motion in transversal and frontal planes as well as may potentially increase the risk of degenerative knee injuries.The overall results of the abduction and internal

  1. The Waist Width of Skis Influences the Kinematics of the Knee Joint in Alpine Skiing

    PubMed Central

    Zorko, Martin; Nemec, Bojan; Babič, Jan; Lešnik, Blaz; Supej, Matej

    2015-01-01

    Recently alpine skis with a wider waist width, which medially shifts the contact between the ski edge and the snow while turning, have appeared on the market. The aim of this study was to determine the knee joint kinematics during turning while using skis of different waist widths (65mm, 88mm, 110mm). Six highly skilled skiers performed ten turns on a predefined course (similar to a giant slalom course). The relation of femur and tibia in the sagital, frontal and coronal planes was captured by using an inertial motion capture suit, and Global Navigation Satellite System was used to determine the skiers’ trajectories. With respect of the outer ski the knee joint flexion, internal rotation and abduction significantly decreased with the increase of the ski waist width for the greatest part of the ski turn. The greatest abduction with the narrow ski and the greatest external rotation (lowest internal rotation) with the wide ski are probably the reflection of two different strategies of coping the biomechanical requirements in the ski turn. These changes in knee kinematics were most probably due to an active adaptation of the skier to the changed biomechanical conditions using wider skis. The results indicated that using skis with large waist widths on hard, frozen surfaces could bring the knee joint unfavorably closer to the end of the range of motion in transversal and frontal planes as well as potentially increasing the risk of degenerative knee injuries. Key points The change in the skis’ waist width caused a change in the knee joint movement strategies, which had a tendency to adapt the skier to different biomechanical conditions. The use of wider skis or, in particular, skis with a large waist width, on a hard or frozen surface, could unfavourably bring the knee joint closer to the end of range of motion in transversal and frontal planes as well as may potentially increase the risk of degenerative knee injuries. The overall results of the abduction and

  2. A New Regional 3-D Velocity Model for Asia from the Joint Inversion of P-Wave Travel Times and Surface-Wave Dispersion Data

    DTIC Science & Technology

    2008-09-30

    global reference model ( Montagner and Kennett, 1996; Kennett et al., 1995). The attenuation profile is held constant everywhere in our model, except over...discrepancy’ between surface waves and body waves that other researchers have described (Baig and Dahlen, 2004; Montagner 216 2008 Monitoring Research...travel times, Geophys. J. Int’l. 122: 108-124. Montagner , J.-P. and B. L. N. Kennett (1996). How to reconcile body-wave and normal-mode reference earth

  3. Successful Strategies for Managing Monteggia Injuries.

    PubMed

    Bae, Donald S

    2016-06-01

    Monteggia fracture-dislocations refer to traumatic ulnar fractures associated with proximal radioulnar and radiocapitellar joint instability. Careful clinical and radiographic evaluation of the entire limb in the acutely injured child is critical for timely diagnosis and appropriate treatment. Treatment principles include restoring and maintaining both ulnar length and alignment as well as radiocapitellar joint reduction. Recent information suggests that surgical treatment of acute injuries associated with complete ulnar fractures is safe and effective in maintaining bone and joint alignment. In cases of late presentation or missed diagnoses, chronic reconstruction may be considered in symptomatic patients with preserved radiocapitellar morphology. Although challenging, ulnar osteotomy and open joint reduction with or without ligament reconstruction may restore joint congruity in the majority of patients.

  4. Autogenic heterotopic vascularized proximal interphalangeal joint transplantation in children.

    PubMed

    Chiu, David T W; Lee, Jonathan

    2011-03-01

    The proximal interphalangeal joint (PIP) joint is the most crucial joint for the functionality of a finger. For a child with complex injury of the hand every effort should be exercised to maximize function restoration. If the PIP joint is irreparably damaged, its reconstruction is indicated. The technique of autogenic heterotopic vascularized toe joint transplantation provides unique advantage of a composite transfer of skin, tendons, bone and joint alone with growth plate and its efficacy has been affirmed in children. It has been suggested that such transfers require intact flexor tendon to achieve satisfactory results, our experience however indicates quite the contrary. As evidenced by this report of a 7-year-old boy with abrasion and avulsion injury to his dominant right hand resulting in a complex defect with skin lose, extensor, flexor avulsion along with cominution of the PIP joint of his long finger. A surgical formulation of staged reconstruction scheme including an autogenic heterotopic vascularized toe joint transplantation led to complete functional restoration to his right hand.

  5. Crustal structure of the eastern Borborema Province, NE Brazil, from the joint inversion of receiver functions and surface wave dispersion: Implications for plateau uplift

    NASA Astrophysics Data System (ADS)

    Luz, Rosana M. N.; Julià, Jordi; Nascimento, Aderson F.

    2015-05-01

    We investigate the crustal structure of the Borborema Province of NE Brazil by developing 44 S wave velocity-depth profiles from the joint inversion of receiver functions and fundamental mode, Rayleigh wave group velocities. The Borborema Province is located in the northeasternmost corner of the South American continent and represents a portion of a larger Neoproterozoic mobile belt that formed during the Brasiliano-Pan African orogeny. Extensional processes in the Mesozoic—eventually leading to the separation of Africa and South America—left a number of aborted rift basins in the continental interiors, and episodes of diffuse intraplate volcanism and uplift marked the evolution of the Province after continental breakup. Our velocity-depth profiles reveal the existence of two crustal types in the Province: (i) the thin crustal type, which consists of 30-32.5 km thick crust, with an upper layer of 3.4-3.6 km/s overlying a lower layer of 3.7-3.8 km/s and (ii) the thick crustal type, which consists of a 35-37.5 km thick crust, with velocities between 3.5 and 3.9 km/s down to ˜30 km depth and a gradational increase in velocity (VS≥4.0 km/s) down to upper mantle depths. The crustal types correlate well with topography, with the thick crustal type being mainly found in the high-standing southern Borborema Plateau and the thin crustal type being mostly found in the low-lying Sertaneja depression and coastal cuestas. Interestingly, the thin crustal type is also observed under the elevated topography of the northern Plateau. We argue that the thick crustal type is rheologically strong and not necessarily related to postbreakup mantle processes, as it is commonly believed. We propose that extensional processes in the Mesozoic stretched portions of the Brasiliano crust and formed the thin crustal type that is now observed in the regions of low-lying topography, leaving the rheologically strong thick crust of the southern Plateau at higher elevations. The crust making

  6. Hand injuries in south Wales coal miners.

    PubMed Central

    Morgan, W J; Harrop, S N

    1985-01-01

    Fifty eight coal miners attended the Royal Gwent Accident and Emergency Department with serious hand injuries over a three year period. The commonest cause of the injuries was falling rock or coal from the pit roof crushing the hand and the commonest type of injury was the crushed, compound fracture of the terminal phalangeal area of the digit, with or without pulp loss. Records of the time off work with the injury were obtained in 52 miners. Only seven (13%) returned to work within one month. Of 40 individual distal phalangeal injuries reviewed after one year, only four (10%) had normal sensation and full movement at the distal joint. Nevertheless, only seven miners (13%) had to alter their initial occupation at the mine and move to lighter duties. Images PMID:4074655

  7. Biomechanical and neuromuscular characteristics of male athletes: implications for the development of anterior cruciate ligament injury prevention programs.

    PubMed

    Sugimoto, Dai; Alentorn-Geli, Eduard; Mendiguchía, Jurdan; Samuelsson, Kristian; Karlsson, Jon; Myer, Gregory D

    2015-06-01

    Prevention of anterior cruciate ligament (ACL) injury is likely the most effective strategy to reduce undesired health consequences including reconstruction surgery, long-term rehabilitation, and pre-mature osteoarthritis occurrence. A thorough understanding of mechanisms and risk factors of ACL injury is crucial to develop effective prevention programs, especially for biomechanical and neuromuscular modifiable risk factors. Historically, the available evidence regarding ACL risk factors has mainly involved female athletes or has compared male and female athletes without an intra-group comparison for male athletes. Therefore, the principal purpose of this article was to review existing evidence regarding the investigation of biomechanical and neuromuscular characteristics that may imply aberrant knee kinematics and kinetics that would place the male athlete at risk of ACL injury. Biomechanical evidence related to knee kinematics and kinetics was reviewed by different planes (sagittal and frontal/coronal), tasks (single-leg landing and cutting), situation (anticipated and unanticipated), foot positioning, playing surface, and fatigued status. Neuromuscular evidence potentially related to ACL injury was reviewed. Recommendations for prevention programs for ACL injuries in male athletes were developed based on the synthesis of the biomechanical and neuromuscular characteristics. The recommendations suggest performing exercises with multi-plane biomechanical components including single-leg maneuvers in dynamic movements, reaction to and decision making in unexpected situations, appropriate foot positioning, and consideration of playing surface condition, as well as enhancing neuromuscular aspects such as fatigue, proprioception, muscle activation, and inter-joint coordination.

  8. RSRM Nozzle-to-Case Joint J-leg Development

    NASA Technical Reports Server (NTRS)

    Albrechtsen, Kevin U.; Eddy, Norman F.; Ewing, Mark E.; McGuire, John R.

    2003-01-01

    Since the beginning of the Space Shuttle Reusable Solid Rocket Motor (RSRM) program, nozzle-to-case joint polysulfide adhesive gas paths have occurred on several flight motors. These gas paths have allowed hot motor gases to reach the wiper O-ring. Even though these motors continue to fly safely with this condition, a desire was to reduce such occurrences. The RSRM currently uses a J-leg joint configuration on case field joints and igniter inner and outer joints. The J-leg joint configuration has been successfully demonstrated on numerous RSRM flight and static test motors, eliminating hot gas intrusion to the critical O-ring seals on these joints. Using the proven technology demonstrated on the case field joints and igniter joints, a nozzle-to-case joint J-leg design was developed for implementation on RSRM flight motors. This configuration provides an interference fit with nozzle fixed housing phenolics at assembly, with a series of pressurization gaps incorporated outboard of the joint mating surface to aid in joint pressurization and to eliminate any circumferential flow in this region. The joint insulation is bonded to the nozzle phenolics using the same pressure sensitive adhesive used in the case field joints and igniter joints. An enhancement to the nozzle-to-case joint J-leg configuration is the implementation of a carbon rope thermal barrier. The thermal barrier is located downstream of the joint bondline and is positioned within the joint in a manner where any hot gas intrusion into the joint passes through the thermal barrier, reducing gas temperatures to a level that would not affect O-rings downstream of the thermal barrier. This paper discusses the processes used in reaching a final nozzle-to-case joint J-leg design, provides structural and thermal results in support of the design, and identifies fabrication techniques and demonstrations used in arriving at the final configuration.

  9. Early osteoarthritis of the patellofemoral joint.

    PubMed

    Arendt, Elizabeth A; Berruto, Massimo; Filardo, Giuseppe; Ronga, Mario; Zaffagnini, Stefano; Farr, Jack; Ferrua, Paolo; Grassi, Alberto; Condello, Vincenzo

    2016-06-01

    Patellofemoral joint cartilage lesions are associated with a variety of clinical situations including blunt trauma, lateral patella dislocations, or as a secondary development in the setting of abnormal joint loading. There is a need for more clarity on how to best address these lesions. Most specifically, when is it necessary to surgically treat these lesions of the patella and trochlea and which technique to use? This review will focus on the spectrum of patellofemoral disease/injury and their treatment strategies, with special emphasis on cartilage damage and early osteoarthritis. Chapter sections will review the most common scenarios of cartilage damage in the patellofemoral joint, with an attempt to summarize current treatment, their outcomes, remaining challenges and unanswered questions.

  10. Overuse lower extremity injuries in sports.

    PubMed

    Fullem, Brian W

    2015-04-01

    When athletes train harder the risk of injury increases, and there are several common overuse injuries to the lower extremity. Three of the most common lower extremity overuse injuries in sports are discussed including the diagnosis and treatments: medial tibal stress syndrome, iliotibial band syndrome, and stress fractures. The charge of sports medicine professionals is to identify and treat the cause of the injuries and not just treat the symptoms. Symptomatology is an excellent guide to healing and often the patient leads the physician to the proper diagnosis through an investigation of the athlete's training program, past injury history, dietary habits, choice of footwear, and training surface.

  11. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... arthritis, or JRA), systemic lupus erythematosus (SLE), and Lyme disease. Joint aspiration is diagnostic but it also can ... Parents MORE ON THIS TOPIC Evaluate Your Child's Lyme Disease Risk Living With Lupus Bones, Muscles, and Joints ...

  12. Culture - joint fluid

    MedlinePlus

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of joint ...

  13. Temporomandibular Joint Dysfunction

    MedlinePlus

    The temporomandibular joint (TMJ) connects your jaw to the side of your head. When it works well, it enables you to ... For people with TMJ dysfunction, problems with the joint and muscles around it may cause Pain that ...

  14. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  15. Large displacement spherical joint

    DOEpatents

    Bieg, Lothar F.; Benavides, Gilbert L.

    2002-01-01

    A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.

  16. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  17. Patterns in Blast Injuries to the Hand

    PubMed Central

    Buntic, Rudolf F.; Brooks, Darrell

    2008-01-01

    Blast injuries to the hand are not just a wartime phenomenon but also quite common in rural communities throughout northern California. The purpose of this study is to review our experience with blast injuries in the community and review the most common patterns in an attempt to identify the pathomechanics of the hand injury and the reconstructive procedures that are required. This is a retrospective study of blast injuries to the hand treated between 1978 and 2006. Medical records, X-rays, and photos were reviewed to compile standard patient demographics and characterize the injury pattern. Explosives were classified based on their rate of decomposition. Reconstructive solutions were reviewed and characterized based on whether damaged tissues were repaired or replaced. Sixty-two patients were identified with blast injuries to their hand. Patients were predominantly male (92%) with an average age of 27 years. Firecrackers were the most commonly encountered explosives. Thirty-seven patients were identified as holding a low explosive in their dominant hand and were used for characterization of the injury pattern. The apparent pattern of injury was hyperextension and hyperabduction of the hand and digits. Common injuries were metacarpophalangeal and interphalangeal joint hyperextension with associated soft tissue avulsion, hyperabduction at the web spaces with associated palmar soft tissue tears, and finger disarticulation amputations worse at radial digits. Given the mechanisms of injury with tissue loss, surgical intervention generally involved tissue replacement rather than tissue repair. Blast injuries to the hand represent a broad spectrum of injuries that are associated with the magnitude of explosion and probably, the proximity to the hand. We were able to identify a repetitive pattern of injury and demonstrate the predominant use for delayed tissue replacement rather than microsurgical repair at the acute setting. PMID:18780004

  18. Avoiding Shoulder Injury from Resistance Training.

    ERIC Educational Resources Information Center

    Durall, Chris J.; Manske, Robert C.; Davies, George J.

    2001-01-01

    Identifies shoulder exercises commonly performed in fitness centers that may contribute to or exacerbate glenohumeral joint (shoulder) injury, describing alternative exercises that may be substituted and a offering rationale for the variations. The article focuses on anterior and posterior glenohumeral instability, subacromial impingement (primary…

  19. Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, Panel Post, Tie & Diagonal Brace Joint Detail; Chord, Panel Post, Tie & Crossbracing Joint Detail - Dunlapsville Covered Bridge, Spanning East Fork Whitewater River, Dunlapsville, Union County, IN

  20. [Pattern of injuries and prophylaxis in paragliding].

    PubMed

    Schulze, W; Hesse, B; Blatter, G; Schmidtler, B; Muhr, G

    2000-06-01

    This study will present trends and recommendations to increase active and passive safety in paragliding on the basis of current state-of-the-art equipment and typical patterns of injury. This German-Swiss teamwork presents data of 55 male and 9 female patients treated after paragliding accidents between 1994 to 1998 respectively 1996 to 1998. 43.7% of the pilots presented with multiple injuries, 62.5% suffered spinal fractures and 18.8% pelvic fractures. 28.4% of the injured pilots were admitted with injuries of the lower extremities mainly affecting the tarsus or the ankle joint. Only three patients with single injuries could be treated in an ambulatory setting. 54.0% of the injuries left the patients with lasting functional residues and complaints. Main causes of accidents were either pilot error in handling the paraglider or general lack of awareness about potential risk factors. 46.0% of injuries occurred during landing, 42.9% of injuries during the flight and another 11.1% of injuries during starting procedures. With noticeable enhanced performance sails of the beginners and intermediate level are increasingly popular. Protective helmets and sturdy footwear reaching above the ankle joint are indispensable pieces of equipment. The use of protective gloves is highly recommended. Back protection devices of the new generation provide the best passive prophylaxis for the pilot against pelvic and spinal cord injuries. This area hold the most promise for increasing safety and reducing risk of injury in future, apart from using beginners and intermediate wings. After acquisition of the pilot license performance and security training provide the best preparing to master unforeseeable situations.

  1. Two-axis joint assembly and method

    NASA Technical Reports Server (NTRS)

    Le, Thang D. (Inventor); Lewis, James L. (Inventor); Carroll, Monty B. (Inventor)

    2010-01-01

    In an embodiment, a two-axis joint that utilizes planar reactions to handle moments applied to the side of the joint thereby allowing the device to remain low profile and compact with minimal intrusion to the mounting surface of the two-axis joint. To handle larger moments, the diameter of the planar member can be increased without increasing the overall height of the joint assembly thereby retaining the low profile thereof. Upper and lower antifriction bearings may be positioned within a housing engage the planar member to reduce rotational friction. The upper and lower bearings and a hub which supports the planar member transfer forces produced by moments applied to the side of the joint so as to spread the forces over the area of the housing.

  2. Spatial and Temporal Antarctic Ice Sheet Mass Trends, Glacio-Isostatic Adjustment, and Surface Processes from a Joint Inversion of Satellite Altimeter, Gravity, and GPS Data

    NASA Technical Reports Server (NTRS)

    Martin-Espanol, Alba; Zammit-Mangion, Andrew; Clarke, Peter J.; Flament, Thomas; Helm, Veit; King, Matt A.; Luthcke, Scott B.; Petrie, Elizabeth; Remy, Frederique; Schon, Nana; Wouters, Bert; Bamber, Jonathan L.

    2016-01-01

    We present spatiotemporal mass balance trends for the Antarctic Ice Sheet from a statistical inversion of satellite altimetry, gravimetry, and elastic-corrected GPS data for the period 2003-2013. Our method simultaneously determines annual trends in ice dynamics, surface mass balance anomalies, and a time-invariant solution for glacio-isostatic adjustment while remaining largely independent of forward models. We establish that over the period 2003-2013, Antarctica has been losing mass at a rateof -84 +/- 22 Gt per yr, with a sustained negative mean trend of dynamic imbalance of -111 +/- 13 Gt per yr. West Antarctica is the largest contributor with -112 +/- 10 Gt per yr, mainly triggered by high thinning rates of glaciers draining into the Amundsen Sea Embayment. The Antarctic Peninsula has experienced a dramatic increase in mass loss in the last decade, with a mean rate of -28 +/- 7 Gt per yr and significantly higher values for the most recent years following the destabilization of the Southern Antarctic Peninsula around 2010. The total mass loss is partly compensated by a significant mass gain of 56 +/- 18 Gt per yr in East Antarctica due to a positive trend of surface mass balance anomalies.

  3. Spatial and temporal Antarctic Ice Sheet mass trends, glacio-isostatic adjustment, and surface processes from a joint inversion of satellite altimeter, gravity, and GPS data.

    PubMed

    Martín-Español, Alba; Zammit-Mangion, Andrew; Clarke, Peter J; Flament, Thomas; Helm, Veit; King, Matt A; Luthcke, Scott B; Petrie, Elizabeth; Rémy, Frederique; Schön, Nana; Wouters, Bert; Bamber, Jonathan L

    2016-02-01

    We present spatiotemporal mass balance trends for the Antarctic Ice Sheet from a statistical inversion of satellite altimetry, gravimetry, and elastic-corrected GPS data for the period 2003-2013. Our method simultaneously determines annual trends in ice dynamics, surface mass balance anomalies, and a time-invariant solution for glacio-isostatic adjustment while remaining largely independent of forward models. We establish that over the period 2003-2013, Antarctica has been losing mass at a rate of -84 ± 22 Gt yr(-1), with a sustained negative mean trend of dynamic imbalance of -111 ± 13 Gt yr(-1). West Antarctica is the largest contributor with -112 ± 10 Gt yr(-1), mainly triggered by high thinning rates of glaciers draining into the Amundsen Sea Embayment. The Antarctic Peninsula has experienced a dramatic increase in mass loss in the last decade, with a mean rate of -28 ± 7 Gt yr(-1) and significantly higher values for the most recent years following the destabilization of the Southern Antarctic Peninsula around 2010. The total mass loss is partly compensated by a significant mass gain of 56 ± 18 Gt yr(-1) in East Antarctica due to a positive trend of surface mass balance anomalies.

  4. Spatial and temporal Antarctic Ice Sheet mass trends, glacio-isostatic adjustment, and surface processes from a joint inversion of satellite altimeter, gravity, and GPS data

    NASA Astrophysics Data System (ADS)

    Martín-Español, Alba; Zammit-Mangion, Andrew; Clarke, Peter J.; Flament, Thomas; Helm, Veit; King, Matt A.; Luthcke, Scott B.; Petrie, Elizabeth; Rémy, Frederique; Schön, Nana; Wouters, Bert; Bamber, Jonathan L.

    2016-02-01

    We present spatiotemporal mass balance trends for the Antarctic Ice Sheet from a statistical inversion of satellite altimetry, gravimetry, and elastic-corrected GPS data for the period 2003-2013. Our method simultaneously determines annual trends in ice dynamics, surface mass balance anomalies, and a time-invariant solution for glacio-isostatic adjustment while remaining largely independent of forward models. We establish that over the period 2003-2013, Antarctica has been losing mass at a rate of -84 ± 22 Gt yr-1, with a sustained negative mean trend of dynamic imbalance of -111 ± 13 Gt yr-1. West Antarctica is the largest contributor with -112 ± 10 Gt yr-1, mainly triggered by high thinning rates of glaciers draining into the Amundsen Sea Embayment. The Antarctic Peninsula has experienced a dramatic increase in mass loss in the last decade, with a mean rate of -28 ± 7 Gt yr-1 and significantly higher values for the most recent years following the destabilization of the Southern Antarctic Peninsula around 2010. The total mass loss is partly compensated by a significant mass gain of 56 ± 18 Gt yr-1 in East Antarctica due to a positive trend of surface mass balance anomalies.

  5. Joint Enrollment Report, 2014

    ERIC Educational Resources Information Center

    Iowa Department of Education, 2014

    2014-01-01

    The Iowa Department of Education collects information on joint enrollment in Iowa's 15 community colleges. Jointly enrolled students are high school students enrolled in community college credit coursework. Most jointly enrolled students enroll through Senior Year Plus (SYP) programs such as Postsecondary Enrollment Options (PSEO) and concurrent…

  6. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Joint Aspiration (Arthrocentesis) KidsHealth > For Parents > Joint Aspiration (Arthrocentesis) Print A A A What's in ... español Aspiración articular (artrocentesis) What It Is A joint aspiration (arthrocentesis) is a test that involves withdrawing ( ...

  7. Bone contusion progression from traumatic knee injury: association of rate of contusion resolution with injury severity

    PubMed Central

    Pedersen, Douglas R; El-Khoury, Georges Y; Thedens, Dan R; Saad-Eldine, Mothana; Phisitkul, Phinit; Amendola, Annunziato

    2017-01-01

    Background Bone contusions are frequently encountered in magnetic resonance imaging (MRI) evaluation of knee anterior cruciate ligament (ACL) injuries. Their role as indicators of injury severity remains unclear, primarily due to indeterminate levels of joint injury forces and to a lack of preinjury imaging. Purpose The purpose of this study was to 1) quantify bone contusion pathogenesis following traumatic joint injuries using fixed imaging follow-ups, and 2) assess the feasibility of using longitudinal bone contusion volumes as an indicator of knee injury severity. Study design Prospective sequential MRI follow-ups of a goat cohort exposed to controlled stifle trauma in vivo were compared to parallel clinical MRI follow-ups of a human ACL tear patient series. Methods Reproducible cartilage impact damage of various energy magnitudes was applied in a survival goat model, coupled with partial resection of anterior portions of medial menisci. Both emulate injury patterns to the knee osteochondral structures commonly encountered in human ACL injury imaging as well as instability from resultant ligament laxity. Longitudinal clinical MRI sequences portrayed stifle bone contusion evolution through 6 months after the inciting event. Results In the first 2 weeks, biological response variability dominated the whole-joint response with no apparent correlation to trauma severity. Control goats subjected to partial meniscectomy alone exhibited minimal bone response. Thereafter, 0.6 J impact bone contusions portrayed a faster rate of resolution than those induced by 1.2 J cartilage impacts. Conclusion Bone contusion sizes combined with time of persistence are likely better measures of joint injury severity than isolated bone contusion volume. PMID:28203112

  8. Cold injuries.

    PubMed

    Long, William B; Edlich, Richard F; Winters, Kathryne L; Britt, L D

    2005-01-01

    Exposure to cold can produce a variety of injuries that occur as a result of man's inability to adapt to cold. These injuries can be divided into localized injury to a body part, systemic hypothermia, or a combination of both. Body temperature may fall as a result of heat loss by radiation, evaporation, conduction, and convection. Hypothermia or systemic cold injury occurs when the core body temperature has decreased to 35 degrees C (95 degrees F) or less. The causes of hypothermia are either primary or secondary. Primary, or accidental, hypothermia occurs in healthy individuals inadequately clothed and exposed to severe cooling. In secondary hypothermia, another illness predisposes the individual to accidental hypothermia. Hypothermia affects multiple organs with symptoms of hypothermia that vary according to the severity of cold injury. The diagnosis of hypothermia is easy if the patient is a mountaineer who is stranded in cold weather. However, it may be more difficult in an elderly patient who has been exposed to a cold environment. In either case, the rectal temperature should be checked with a low-reading thermometer. The general principals of prehospital management are to (1) prevent further heat loss, (2) rewarm the body core temperature in advance of the shell, and (3) avoid precipitating ventricular fibrillation. There are two general techniques of rewarming--passive and active. The mechanisms of peripheral cold injury can be divided into phenomena that affect cells and extracellular fluids (direct effects) and those that disrupt the function of the organized tissue and the integrity of the circulation (indirect effects). Generally, no serious damage is seen until tissue freezing occurs. The mildest form of peripheral cold injury is frostnip. Chilblains represent a more severe form of cold injury than frostnip and occur after exposure to nonfreezing temperatures and damp conditions. Immersion (trench) foot, a disease of the sympathetic nerves and blood

  9. Sex Differences in Proximal Control of the Knee Joint

    PubMed Central

    Mendiguchia, Jurdan; Ford, Kevin R.; Quatman, Carmen E.; Alentorn-Geli, Eduard; Hewett, Timothy E.

    2014-01-01

    Following the onset of maturation, female athletes have a significantly higher risk for anterior cruciate ligament (ACL) injury compared with male athletes. While multiple sex differences in lower-extremity neuromuscular control and biomechanics have been identified as potential risk factors for ACL injury in females, the majority of these studies have focused specifically on the knee joint. However, increasing evidence in the literature indicates that lumbopelvic (core) control may have a large effect on knee-joint control and injury risk. This review examines the published evidence on the contributions of the trunk and hip to knee-joint control. Specifically, the sex differences in potential proximal controllers of the knee as risk factors for ACL injury are identified and discussed. Sex differences in trunk and hip biomechanics have been identified in all planes of motion (sagittal, coronal and transverse). Essentially, female athletes show greater lateral trunk displacement, altered trunk and hip flexion angles, greater ranges of trunk motion, and increased hip adduction and internal rotation during sport manoeuvres, compared with their male counterparts. These differences may increase the risk of ACL injury among female athletes. Prevention programmes targeted towards trunk and hip neuromuscular control may decrease the risk for ACL injuries. PMID:21688868

  10. Pressure-actuated joint system

    NASA Technical Reports Server (NTRS)

    McGuire, John R. (Inventor)

    2004-01-01

    A pressure vessel is provided that includes first and second case segments mated with one another. First and second annular rubber layers are disposed inboard of the first and second case segments, respectively. The second annular rubber layer has a slot extending from the radial inner surface across a portion of its thickness to define a main body portion and a flexible portion. The flexible portion has an interfacing surface portion abutting against an interfacing surface portion of the first annular rubber layer to follow movement of the first annular rubber layer during operation of the pressure vessel. The slot receives pressurized gas and establishes a pressure-actuated joint between the interfacing surface portions. At least one of the interfacing surface portions has a plurality of enclosed and sealed recesses formed therein.

  11. Inspection of Fusion Joints in Plastic Pipe

    SciTech Connect

    Connie Reichert

    2005-09-01

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost-effective method exists for assessing the quality of fusion joints in the field. Visual examination and pressure testing are current nondestructive approaches, which do not provide any assurance about the long-term pipeline performance. This project developed, demonstrated, and validated an in-situ nondestructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system includes a laser-based image-recognition system that automatically generates and interprets digital images of pipe joints and assigns them a pass/fail rating, which eliminates operator bias in evaluating joint quality. An EWI-patented process, the Weld Zone Inspection Method (WZIM) was developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation, which reveals the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and nonstandard conditions. These welds were subjected to the WZIM and two destructive forms of testing: short-term tensile testing and long-term creep rupture testing. There appears to be a direct correlation between the WZIM and the destructive testing results. Although WZIM appears to be more sensitive than destructive testing can verify, the approach appears valid.

  12. INSPECTION OF FUSION JOINTS IN PLASTIC PIPE

    SciTech Connect

    Alex Savitski; Connie Reichert; John Coffey

    2005-07-13

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost effective method of assessing the quality of fusion joints in the field exists. Visual examination and pressure testing are current non-destructive approaches, which do not provide any assurance about the long-term pipeline performance. This project will develop, demonstrate, and validate an in-situ non-destructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system will include a laser based image-recognition system that will automatically generate and interpret digital images of pipe joints and assign them a pass/fail rating, which eliminates operator bias in evaluating joint quality. A Weld Zone Inspection Method (WZIM) is being developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation and reveal the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and nonstandard conditions. These welds were subjected to the WZIM and tensile testing. There appears to be a direct correlation between the WZIM and tensile testing results. Although WZIM appears to be more sensitive than tensile testing can verify, the approach appears valid.

  13. INSPECTION OF FUSION JOINTS IN PLASTIC PIPE

    SciTech Connect

    Alex Savitski; Connie Reichert; John Coffey

    2004-07-13

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost effective method of assessing the quality of fusion joints in the field exists. Visual examination and pressure testing are current non-destructive approaches, which do not provide any assurance about the long-term pipeline performance. This project will develop, demonstrate, and validate an in-situ non-destructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system will include a laser based image-recognition system that will automatically generate and interpret digital images of pipe joints and assign them a pass/fail rating, which eliminates operator bias in evaluating joint quality. A Weld Zone Inspection Method (WZIM) is being developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation and reveal the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and non-standard conditions. These welds were subjected to the WZIM and tensile testing. There appears to be a direct correlation between the WZIM and tensile testing results. Although WZIM appears to be more sensitive than tensile testing can verify, the approach appears valid.

  14. INSPECTION OF FUSION JOINTS IN PLASTIC PIPE

    SciTech Connect

    Alex Savitski; Connie Reichert; John Coffey

    2004-10-29

    The standard method of joining plastic pipe in the field is the butt fusion process. As in any pipeline application, joint quality greatly affects overall operational safety of the system. Currently no simple, reliable, cost effective method of assessing the quality of fusion joints in the field exists. Visual examination and pressure testing are current non-destructive approaches, which do not provide any assurance about the long-term pipeline performance. This project will develop, demonstrate, and validate an in-situ non-destructive inspection method for butt fusion joints in gas distribution plastic pipelines. The inspection system will include a laser based image-recognition system that will automatically generate and interpret digital images of pipe joints and assign them a pass/fail rating, which eliminates operator bias in evaluating joint quality. A Weld Zone Inspection Method (WZIM) is being developed in which local heat is applied to the joint region to relax the residual stresses formed by the original joining operation and reveal the surface condition of the joint. In cases where the joint is not formed under optimal conditions, and the intermolecular forces between contacting surfaces are not strong enough, the relaxation of macromolecules in the surface layer causes the material to pull back, revealing a fusion line. If the joint is sound, the bond line image does not develop. To establish initial feasibility of the approach, welds were performed under standard and non-standard conditions. These welds were subjected to the WZIM and tensile testing. There appears to be a direct correlation between the WZIM and tensile testing results. Although WZIM appears to be more sensitive than tensile testing can verify, the approach appears valid.

  15. Modelling the Shear Behaviour of Rock Joints with Asperity Damage Under Constant Normal Stiffness

    NASA Astrophysics Data System (ADS)

    Indraratna, Buddhima; Thirukumaran, Sivanathan; Brown, E. T.; Zhu, Song-Ping

    2015-01-01

    The shear behaviour of a rough rock joint depends largely on the surface properties of the joint, as well as the boundary conditions applied across the joint interface. This paper proposes a new analytical model to describe the complete shear behaviour of rough joints under constant normal stiffness (CNS) boundary conditions by incorporating the effect of damage to asperities. In particular, the effects of initial normal stress levels and joint surface roughness on the shear behaviour of joints under CNS conditions were studied, and the analytical model was validated through experimental results. Finally, the practical application of the model to a jointed rock slope stability analysis is presented.

  16. Bonded and Bolted Graphite/Polyimide Composite Joints

    NASA Technical Reports Server (NTRS)

    Skoumal, D. E.; Cushman, J. B.

    1985-01-01

    Four types of high-temperature joints designed for control surfaces. Design, analysis, and testing performed to develop four types of graphite/polyimide bonded and bolted composite joints for lightly loaded control surfaces on advanced transportation systems that operate at temperatures up to 550 degrees F (288 degrees C).

  17. How do training and competition workloads relate to injury? The workload-injury aetiology model.

    PubMed

    Windt, Johann; Gabbett, Tim J

    2017-03-01

    Injury aetiology models that have evolved over the previous two decades highlight a number of factors which contribute to the causal mechanisms for athletic injuries. These models highlight the pathway to injury, including (1) internal risk factors (eg, age, neuromuscular control) which predispose athletes to injury, (2) exposure to external risk factors (eg, playing surface, equipment), and finally (3) an inciting event, wherein biomechanical breakdown and injury occurs. The most recent aetiological model proposed in 2007 was the first to detail the dynamic nature of injury risk, whereby participation may or may not result in injury, and participation itself alters injury risk through adaptation. However, although training and competition workloads are strongly associated with injury, existing aetiology models neither include them nor provide an explanation for how workloads alter injury risk. Therefore, we propose an updated injury aetiology model which includes the effects of workloads. Within this model, internal risk factors are differentiated into modifiable and non-modifiable factors, and workloads contribute to injury in three ways: (1) exposure to external risk factors and potential inciting events, (2) fatigue, or negative physiological effects, and (3) fitness, or positive physiological adaptations. Exposure is determined solely by total load, while positive and negative adaptations are controlled both by total workloads, as well as changes in load (eg, the acute:chronic workload ratio). Finally, we describe how this model explains the load-injury relationships for total workloads, acute:chronic workload ratios and the training load-injury paradox.

  18. Lightning injuries.

    PubMed

    O'Keefe Gatewood, Medley; Zane, Richard D

    2004-05-01

    Lightning is persistently one of the leading causes of death caused by environmental or natural disaster. To understand the pathophysiology and treatment of lightning injuries one must first discount the innumerable myths, superstitions, and misconceptions surrounding lightning. The fundamental difference between high voltage electrical injury and lightning is the duration of exposure to current. Reverse triage should be instituted in lightning strike victims because victims in cardiopulmonary arrest might gain the greatest benefit from resuscitation efforts, although there is no good evidence suggesting that lightning strike victims might benefit from longer than usual resuscitation times. Many of the injuries suffered by lightning strike victims are unique to lightning, and long-term sequelae should be anticipated and addressed in the lightning victim.

  19. Blast Injury

    PubMed Central

    de Candole, C. A.

    1967-01-01

    The shock wave generated by an explosion (“blast wave”) may cause injury in any or all of the following: (1) direct impact on the tissues of variations in environmental pressure; (2) flying glass and other debris set in motion by it; (3) propulsion of the body. Injuries in the first category affect gas-containing organs (ears, lungs and intestines), and acute death is attributed to air forced into the coronary vessels via damaged pulmonary alveoli. It is estimated that overpressure sufficient to cause lung injury may occur up to five miles from a 20-megaton nuclear explosion. The greatest single hazard from blast is, however, flying glass, and serious wounding from this cause is possible up to 12 miles from an explosion of this magnitude. PMID:6015742

  20. Hamstring injuries

    PubMed Central

    Guanche, Carlos A.

    2015-01-01

    There is a continuum of hamstring injuries that can range from musculotendinous strains to avulsion injuries. Although the proximal hamstring complex has a strong bony attachment on the ischial tuberosity, hamstring injuries are common in athletic population and can affect all levels of athletes. Nonoperative treatment is mostly recommended in the setting of low-grade partial tears and insertional tendinosis. However, failure of nonoperative treatment of partial tears may benefit from surgical debridement and repair. The technique presented on this article allows for the endoscopic management of proximal hamstring tears and chronic ischial bursitis, which until now has been managed exclusively with much larger open approaches. The procedure allows for complete exposure of the posterior aspect of the hip in a safe, minimally invasive fashion. PMID:27011828