Limited fiber type grouping in self-reinnervation cat tibialis anterior muscles.

PubMed

Unguez, G A; Roy, R R; Bodine-Fowler, S; Edgerton, V R

1996-10-01

The percent and distribution patterns of three immunohistochemically identified fiber types within the anterior compartment of the cat tibialis anterior were determined 6 months after denervation and self-reinnervation. After self-reinnervation, mean frequencies of slow (9%) and fast (91%) fibers were similar to those in control (12% and 88%, respectively) muscles. However, a lower proportion of fast-1 (26%) and a higher proportion of fast-2 (65%) fibers were observed in self-reinnervated than control (32% and 56%) muscles. Quantitation of adjacencies between fibers of similar myosin heavy chain (MHC) phenotype, a measure of type grouping, revealed that the frequencies of two slow or two fast-1 fibers being adjacent in self-reinnervated muscles were similar to control. In contrast, the frequency of fast-2/fast-2 fiber adjacencies found in self-reinnervated muscles (45%) was significantly higher than in control muscles (37%). In both groups, the frequency of adjacencies between slow, fast-1, or fast-2 fibers was largely attributable to the number of each fiber type present. These data show that the incidence of grouping within each fiber type present was not altered after 6 months of self-reinnervation. Minimal changes in the spatial distribution of fiber types following self-reinnervation in adults suggests a limited degree of conversion of muscle fibers to a MHC phenotype matching the motoneuron characteristics.

Upper extremity limb loss: functional restoration from prosthesis and targeted reinnervation to transplantation.

PubMed

Carlsen, Brian T; Prigge, Pat; Peterson, Jennifer

2014-01-01

For several decades, prosthetic use was the only option to restore function after upper extremity amputation. Recent years have seen advances in the field of prosthetics. Such advances include prosthetic design and function, activity-specific devices, improved aesthetics, and adjunctive surgical procedures to improve both form and function. Targeted reinnervation is one exciting advance that allows for more facile and more intuitive function with prosthetics following proximal amputation. Another remarkable advance that holds great promise in nearly all fields of medicine is the transplantation of composite tissue, such as hand and face transplantation. Hand transplantation holds promise as the ultimate restorative procedure that can provide form, function, and sensation. However, this procedure still comes with a substantial cost in terms of the rehabilitation and toxic immunosuppression and should be limited to carefully selected patients who have failed prosthetic reconstruction. Hand transplantation and prosthetic reconstruction should not be viewed as competing options. Rather, they are two treatment options with different risk/benefit profiles and different indications and, hence vastly different implications. Copyright © 2014 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Reinnervation following catheter-based radio-frequency renal denervation.

PubMed

Booth, Lindsea C; Nishi, Erika E; Yao, Song T; Ramchandra, Rohit; Lambert, Gavin W; Schlaich, Markus P; May, Clive N

2015-04-20

What is the topic of this review? Does catheter-based renal denervation effectively denervate the afferent and efferent renal nerves and does reinnervation occur? What advances does it highlight? Following catheter-based renal denervation, the afferent and efferent responses to electrical stimulation were abolished, renal sympathetic nerve activity was absent, and levels of renal noradrenaline and immunohistochemistry for tyrosine hydroxylase and calcitonin gene-related peptide were significantly reduced. By 11 months after renal denervation, both the functional responses and anatomical markers of afferent and efferent renal nerves had returned to normal, indicating reinnervation. Renal denervation reduces blood pressure in animals with experimental hypertension and, recently, catheter-based renal denervation was shown to cause a prolonged decrease in blood pressure in patients with resistant hypertension. The randomized, sham-controlled Symplicity HTN-3 trial failed to meet its primary efficacy end-point, but there is evidence that renal denervation was incomplete in many patients. Currently, there is little information regarding the effectiveness of catheter-based renal denervation and the extent of reinnervation. We assessed the effectiveness of renal nerve denervation with the Symplicity Flex catheter and the functional and anatomical reinnervation at 5.5 and 11 months postdenervation. In anaesthetized, non-denervated sheep, there was a high level of renal sympathetic nerve activity, and electrical stimulation of the renal nerve increased blood pressure and reduced heart rate (afferent response) and caused renal vasoconstriction and reduced renal blood flow (efferent response). Immediately after renal denervation, renal sympathetic nerve activity and the responses to electrical stimulation were absent, indicating effective denervation. By 11 months after denervation, renal sympathetic nerve activity was present and the responses to electrical stimulation

Supercharged end-to-side anterior interosseous to ulnar motor nerve transfer for intrinsic musculature reinnervation.

PubMed

Barbour, John; Yee, Andrew; Kahn, Lorna C; Mackinnon, Susan E

2012-10-01

Functional motor recovery after peripheral nerve injury is predominantly determined by the time to motor end plate reinnervation and the absolute number of regenerated motor axons that reach target. Experimental models have shown that axonal regeneration occurs across a supercharged end-to-side (SETS) nerve coaptation. In patients with a recovering proximal ulnar nerve injury, a SETS nerve transfer conceptually is useful to protect and preserve distal motor end plates until the native axons fully regenerate. In addition, for nerve injuries in which incomplete regeneration is anticipated, a SETS nerve transfer may be useful to augment the regenerating nerve with additional axons and to more quickly reinnervate target muscle. We describe our technique for a SETS nerve transfer of the terminal anterior interosseous nerve (AIN) to the pronator quadratus muscle (PQ) end-to-side to the deep motor fascicle of the ulnar nerve in the distal forearm. In addition, we describe our postoperative therapy regimen for these transfers and an evaluation tool for monitoring progressive muscle reinnervation. Although the AIN-to-ulnar motor group SETS nerve transfer was specifically designed for ulnar nerve injuries, we believe that the SETS procedure might have broad clinical utility for second- and third-degree axonotmetic nerve injuries, to augment partial recovery and/or "babysit" motor end plates until the native parent axons regenerate to target. We would consider all donor nerves currently utilized in end-to-end nerve transfers for neurotmetic injuries as candidates for this SETS technique. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Golf hand prosthesis performance of transradial amputees.

PubMed

Carey, Stephanie L; Wernke, Matthew M; Lura, Derek J; Kahle, Jason T; Dubey, Rajiv V; Highsmith, M Jason

2015-06-01

Typical upper limb prostheses may limit sports participation; therefore, specialized terminal devices are often needed. The purpose of this study was to evaluate the ability of transradial amputees to play golf using a specialized terminal device. Club head speed, X-factor, and elbow motion of two individuals with transradial amputations using an Eagle Golf terminal device were compared to a non-amputee during a golf swing. Measurements were collected pre/post training with various stances and grips. Both prosthesis users preferred a right-handed stance initially; however, after training, one preferred a left-handed stance. The amputees had slower club head speeds and a lower X-factor compared to the non-amputee golfer, but increased their individual elbow motion on the prosthetic side after training. Amputees enjoyed using the device, and it may provide kinematic benefits indicated by the increase in elbow flexion on the prosthetic side. The transradial amputees were able to swing a golf club with sufficient repetition, form, and velocity to play golf recreationally. Increased elbow flexion on the prosthetic side suggests a potential benefit from using the Eagle Golf terminal device. Participating in recreational sports can increase amputees' health and quality of life. © The International Society for Prosthetics and Orthotics 2014.

The Winter Park Amputee Ski Teaching System.

ERIC Educational Resources Information Center

O'Leary, Hal

The three track method of teaching amputees to ski is presented in the illustrated manual. Problems unique to amputee skiers--care of hands, conditioning, care of stump, fatigue, excessive standing, wind, and balance--are discussed in terms of their implications to the amputee skier and practical solutions in attempting to solve them. Specific…

Prosthetic Frequently Asked Questions for the New Amputee

MedlinePlus

... with other amputees locally and across the country. WEB ADDRESSES FOR LINKED MATERIALS Amputee Coalition National Limb ... article in other publications, including other World Wide Web sites must contact the Amputee Coalition for permission ...

Contractile properties of rat fast-twitch skeletal muscle during reinnervation - Effects of testosterone and castration

NASA Technical Reports Server (NTRS)

Yeagle, S. P.; Mayer, R. F.; Max, S. R.

1983-01-01

The peroneal nerve of subject rats were crushed 1 cm from the muscle in order to examine the isometric contractile properties of skeletal muscle in the recovery sequency during reinnervation of normal, castrated, and testosterone-treated rats. The particular muscle studied was the extensor digitorum longus, with functional reinnervation first observed 8-9 days after nerve crush. No evidence was found that either castration or testosterone injections altered the process of reinnervation after the nerve crush, with the conclusion being valid at the 0.05 p level. The most reliable index of reinnervation was found to be the twitch:tetanus ratio, a factor of use in future studies of the reinnervation of skeletal muscle.

Bariatric amputee: A growing problem?

PubMed

Kulkarni, Jai; Hannett, Dominic P; Purcell, Steven

2015-06-01

This study reviewed prevalence of patients with lower limb amputations with above normal weight profile, with body mass index over 25, in seven disablement services centres managing their amputee rehabilitation in the United Kingdom. To review two clinical standards of practice in amputee rehabilitation. Ambulant lower limb amputees should have their body weight recorded on an electronic information system, with identification of cohort with body weight >100 kg. Lower limb amputees to be provided with suitable weight-rated prosthesis. Observational study of clinical practice. Data were collected from the Clinical Information Management Systems. Inclusion criteria--subjects were ambulant prosthetic users with some prosthetic intervention in the last 5 years and had at least one lower limb amputation. In 96% of patients, the weight record profile was maintained. In addition, 86% were under 100 kg, which is the most common weight limit of prosthetic componentry. Of 15,204 amputation levels, there were 1830 transfemoral and transtibial sites in users with body weight over 100 kg. In 60 cases, the prosthetic limb build was rated to be below the user body weight. In 96% of our patients, body weight was documented, and in 97%, the prosthetic limb builds were within stated body weight limits, but this may not be the case in all the other disablement services centres in the United Kingdom. Also, the incidence of obesity in the United Kingdom is a growing problem, and the health issues associated with obesity are further compounded in the amputee population. Prosthetic componentry has distinct weight limits which must be considered during prescription. As people with amputation approach the limits of specific components, clinicians are faced with the challenge of continued provision in a safe and suitable manner. This article reviews the amputee population and the current national profile to consider trends in provision and the incidence of these challenges. © The

Cutaneous sensitivity in unilateral trans-tibial amputees

PubMed Central

Templeton, Cale A.; Strzalkowski, Nicholas D. J.; Galvin, Patti

2018-01-01

Aim To examine tactile sensitivity in the leg and foot sole of below-knee amputees (diabetic n = 3, traumatic n = 1), and healthy control subjects (n = 4), and examine the association between sensation and balance. Method Vibration perception threshold (VPT; 3, 40, 250Hz) and monofilaments (MF) were used to examine vibration and light touch sensitivity on the intact limb, residual limb, and homologous locations on controls. A functional reach test was performed to assess functional balance. Results Tactile sensitivity was lower for diabetic amputee subjects compared to age matched controls for both VPT and MF; which was expected due to presence of diabetic peripheral neuropathy. In contrast, the traumatic amputee participant showed increased sensitivity for VPT at 40Hz and 250Hz vibration in both the intact and residual limbs compared to controls. Amputees with lower tactile sensitivity had shorter reach distances compared to those with higher sensitivity. Conclusion Changes in tactile sensitivity in the residual limb of trans-tibial amputees may have implications for the interaction between the amputee and the prosthetic device. The decreased skin sensitivity observed in the residual limb of subjects with diabetes is of concern as changes in skin sensitivity may be important in 1) identification/prevention of excessive pressure and 2) for functional stability. Interestingly, we saw increased residual limb skin sensitivity in the individual with the traumatic amputation. Although not measured directly in the present study, this increase in tactile sensitivity may be related to cortical reorganisation, which is known to occur following amputation, and would support similar findings observed in upper limb amputees. PMID:29856766

New concepts of the reinnervated motor unit revealed by vaccine-associated poliomyelitis.

PubMed

Wiechers, D O

1988-04-01

A late onset of slowly progressive muscle weakness 30-40 years after acute polio is well known. Previous studies by the author and others have demonstrated transmission abnormalities within the reinnervated motor unit. These transmission abnormalities shown by motor unit action potential (MUAP) instability in size and shape with repetitive discharges occurs in postpolio patients who are and who are not complaining of progressive muscle weakness. Although some reinnervated MUAPs do seem to stabilize their neuromuscular transmission with time in mildly affected muscles, the question arises as to whether or not some MUAPs ever stabilize after polio. Two cases of acute polio personally followed by the author, one over a 9 1/2 year period, are presented. In both cases, in muscles where there are more deinnervated muscle fibers than could possibly be reinnervated, the MUAPs have remained unstable. New concepts of function in the reinnervated motor unit following polio are presented.

Voluntary Control of Residual Antagonistic Muscles in Transtibial Amputees: Feedforward Ballistic Contractions and Implications for Direct Neural Control of Powered Lower Limb Prostheses.

PubMed

Huang, Stephanie; Huang, He

2018-04-01

Discrete, rapid (i.e., ballistic like) muscle activation patterns have been observed in ankle muscles (i.e., plantar flexors and dorsiflexors) of able-bodied individuals during voluntary posture control. This observation motivated us to investigate whether transtibial amputees are capable of generating such a ballistic-like activation pattern accurately using their residual ankle muscles in order to assess whether the volitional postural control of a powered ankle prosthesis using proportional myoelectric control via residual muscles could be feasible. In this paper, we asked ten transtibial amputees to generate ballistic-like activation patterns using their residual lateral gastrocnemius and residual tibialis anterior to control a computer cursor via proportional myoelectric control to hit targets positioned at 20% and 40% of maximum voluntary contraction of the corresponding residual muscle. During practice conditions, we asked amputees to hit a single target repeatedly. During testing conditions, we asked amputees to hit a random sequence of targets. We compared movement time to target and end-point accuracy. We also examined motor recruitment synchronization via time-frequency representations of residual muscle activation. The result showed that median end-point error ranged from -0.6% to 1% maximum voluntary contraction across subjects during practice, which was significantly lower compared to testing ( ). Average movement time for all amputees was 242 ms during practice and 272 ms during testing. Motor recruitment synchronization varied across subjects, and amputees with the highest synchronization achieved the fastest movement times. End-point accuracy was independent of movement time. Results suggest that it is feasible for transtibial amputees to generate ballistic control signals using their residual muscles. Future work on volitional control of powered power ankle prostheses might consider anticipatory postural control based on ballistic-like residual

Reinnervation of Urethral and Anal Sphincters With Femoral Motor Nerve to Pudendal Nerve Transfer

PubMed Central

Ruggieri, Michael R.; Braverman, Alan S.; Bernal, Raymond M.; Lamarre, Neil S.; Brown, Justin M.; Barbe, Mary F.

2012-01-01

Aims Lower motor neuron damage to sacral roots or nerves can result in incontinence and a flaccid urinary bladder. We showed bladder reinnervation after transfer of coccygeal to sacral ventral roots, and genitofemoral nerves (L1, 2 origin) to pelvic nerves. This study assesses the feasibility of urethral and anal sphincter reinnervation using transfer of motor branches of the femoral nerve (L2–4 origin) to pudendal nerves (S1, 2 origin) that innervate the urethral and anal sphincters in a canine model. Methods Sacral ventral roots were selected by their ability to stimulate bladder, urethral sphincter, and anal sphincter contraction and transected. Bilaterally, branches of the femoral nerve, specifically, nervus saphenous pars muscularis [Evans HE. Miller’s anatomy of the dog. Philadelphia: W.B. Saunders; 1993], were transferred and end-to-end anastomosed to transected pudendal nerve branches in the perineum, then enclosed in unipolar nerve cuff electrodes with leads to implanted RF micro-stimulators. Results Nerve stimulation induced increased anal and urethral sphincter pressures in five of six transferred nerves. Retrograde neurotracing from the bladder, urethral sphincter, and anal sphincter using fluorogold, fast blue, and fluororuby, demonstrated urethral and anal sphincter labeled neurons in L2–4 cord segments (but not S1–3) in nerve transfer canines, consistent with rein-nervation by the transferred femoral nerve motor branches. Controls had labeled neurons only in S1–3 segments. Postmortem DiI and DiO labeling confirmed axonal regrowth across the nerve repair site. Conclusions These results show spinal cord reinnervation of urethral and anal sphincter targets after sacral ventral root transection and femoral nerve transfer (NT) to the denervated pudendal nerve. These surgical procedures may allow patients to regain continence. PMID:21953679

Skin problems in amputees: a descriptive study.

PubMed

Koc, Erol; Tunca, Mustafa; Akar, Ahmet; Erbil, A Hakan; Demiralp, Bahtiyar; Arca, Ercan

2008-05-01

Skin problems are common in amputee patients. These problems may restrict the normal use of a prosthetic limb. We aimed to determine the range, incidence, causes and patterns of dermatological problems seen in a population of amputees. One hundred and forty two amputees, were enrolled to the study. Age, sex, age at the time of amputation, level of amputation, reason for amputation, and types of prosthesis were noted. Dermatological problems were recorded. Stumps were swabbed for bacteriological and mycological examination, and patch tests were performed in suspected patients. Of these 142 patients, 139 (97.9%) were males and 3 (2.1%) were females. The reasons for amputation in the majority of the cases were wounds due to mine explosion (n = 114, 80.3%) and gunshot wounds (n = 19, 13.4%). The other reasons were arterial diseases, traffic accidents, congenital absence of the tibia, and vascular complication of diabetes. At least one skin problem was detected in 105 (73.9%) of 142 cases. Positive reactions to allergens have been detected in 28 (43%) of 65 cases with dermatitis. Bacterial infection was detected in 12 patients and fungal infection was detected in 4 patients. Our descriptive study shows that skin problems have a high prevalence, up to 73.9% in amputee patients. This high percentage indicates that dermatological problems are important in amputees. Early recognition and treatment of these problems can prevent the amputee's mental, social, and economic losses.

Conversion of muscle fiber types in regenerating chicken muscles following cross-reinnervation.

PubMed

Kikuchi, T; Akiba, T; Ashmore, C R

1986-01-01

Slow-tonic anterior latissimus dorsi (ALD) and fast-twitch posterior latissimus dorsi (PLD) muscles of 7 to 10-day-old White Leghorn chickens were crushed and allowed to be reinnervated by their own nerve, or crushed and transplanted to the other side and allowed to be reinnervated by the nerve of the side to which they were transplanted. Following transplantation, changes in the weight of the muscle, fiber-type composition and innervation pattern during regeneration were investigated. Normal growth rate of PLD was about twice that of ALD. Regenerating PLD, however, atrophied rapidly after crushing and denervation whether innervated by its own nerve or the other nerve type, whereas ALD reinnervated by its own nerve showed marked hypertrophy. PLD fibers transformed rapidly to fast-twitch alpha or slow-tonic (ST) fibers when they were reinnervated by PLD or ALD nerve, respectively. When ALD fibers were reinnervated by their own nerve, they differentiated into ST fibers that were surrounded by smaller immature fibers. ALD fibers were, however, resistant to complete control by fast-twitch PLD nerve and contained a large number of slow fibers (ST and beta) long after transplantation. Slow fibers in regenerates were initially multiply innervated, but later transformed into fast-twitch alpha fibers that were focally innervated. The mode of differentiation and innervation pattern of different muscle fiber types in regenerating muscles are discussed.

Assessment of Self-Esteem and Satisfaction in Amputee Children

ERIC Educational Resources Information Center

Spencer, C. D.; And Others

1977-01-01

The study involving six single and multiple amputee children (10 to 14 years old) was conducted to provide information on how situations affect the self esteem of amputee children, how situations affect satisfaction with their prostheses, and the relationship between amputee self esteem and their satisfaction with their prosthetic device.…

Improved Training Method for Rapid Rehabilitation of Amputees

DTIC Science & Technology

2012-03-01

amputees must be able to manage uneven terrain, crowded environments, stairs , ramps, and hills. The largest problem for a lower extremity amputee is...objective biomechanical variables that are causally related to the success or failure in avoiding a fall after a trip, objective tests to quantify...crowded environments, stairs , ramps, and hills. The key factor that limits the ability of amputees to achieve maximum functional capabilities is falls

The mechanics of landing when stepping down in unilateral lower-limb amputees.

PubMed

Jones, S F; Twigg, P C; Scally, A J; Buckley, J G

2006-02-01

The ability to successfully negotiate stairs and steps is an important factor for functional independence. While work has been undertaken to understand the biomechanics of gait in lower-limb amputees, little is known about how amputees negotiate stairs and steps. This study aimed to determine the mechanics of landing in unilateral lower-limb amputees when stepping down to a new level. A secondary aim was to assess the effects of using a shank-mounted shock-absorbing device (Tele-Torsion Pylon) on the mechanics of landing. Ten unilateral amputees (five transfemoral and five transtibial) and eight able-bodied controls performed single steps down to a new level (73 and 219 mm). Trials were repeated in amputees with the Tele-Torsion Pylon active and inactive. The mechanics of landing were evaluated by analysing peak limb longitudinal force, maximal limb shortening, lower extremity stiffness, and knee joint angular displacement during the initial contact period, and limb and ankle angle at the instant of ground-contact. Data were collected using a Vicon 3D motion analysis system and two force platforms. Amputees landed on a straightened and near vertical limb. This limb position was maintained in transfemoral amputees, whereas in transtibial amputees knee flexion occurred. As a result lower extremity stiffness was significantly greater in transfemoral amputees compared to transtibial amputees and able-bodied controls (P<0.001). The Tele-Torsion Pylon had little effect on the mechanics of landing in transtibial amputees, but brought about a reduction in lower extremity stiffness in transfemoral amputees (P<0.05). Amputees used a stepping strategy that ensured the direction of the ground reaction force vector was kept anterior of the knee joint centre. Using a Tele-Torsion Pylon may improve the mechanics of landing during downward stepping in transfemoral amputees.

Self-reinnervated muscles lose autogenic length feedback, but intermuscular feedback can recover functional connectivity

PubMed Central

Prilutsky, Boris I.; Gregor, Robert J.; Abelew, Thomas A.; Nichols, T. Richard

2016-01-01

In this study, we sought to identify sensory circuitry responsible for motor deficits or compensatory adaptations after peripheral nerve cut and repair. Self-reinnervation of the ankle extensor muscles abolishes the stretch reflex and increases ankle yielding during downslope walking, but it remains unknown whether this finding generalizes to other muscle groups and whether muscles become completely deafferented. In decerebrate cats at least 19 wk after nerve cut and repair, we examined the influence of quadriceps (Q) muscles' self-reinnervation on autogenic length feedback, as well as intermuscular length and force feedback, among the primary extensor muscles in the cat hindlimb. Effects of gastrocnemius and soleus self-reinnervation on intermuscular circuitry were also evaluated. We found that autogenic length feedback was lost after Q self-reinnervation, indicating that loss of the stretch reflex appears to be a generalizable consequence of muscle self-reinnervation. However, intermuscular force and length feedback, evoked from self-reinnervated muscles, was preserved in most of the interactions evaluated with similar relative inhibitory or excitatory magnitudes. These data indicate that intermuscular spinal reflex circuitry has the ability to regain functional connectivity, but the restoration is not absolute. Explanations for the recovery of intermuscular feedback are discussed, based on identified mechanisms responsible for lost autogenic length feedback. Functional implications, due to permanent loss of autogenic length feedback and potential for compensatory adaptations from preserved intermuscular feedback, are discussed. PMID:27306676

Better Mental Component of Quality of Life in Amputee

PubMed Central

Karami, GR; Ahmadi, Kh; Nejati, V; Masumi, M

2012-01-01

Background: Assessment of quality of life can promote health services. The purpose of this study was evaluation of health related quality of life in lower limbs amputee veterans of Iran. Methods: In the present cross sectional study, we compared 38 lower limbs amputee veterans with 50 normal healthy subjects with SF36 questioner in face-to-face interview. Results: Amputees had significantly lower grade than normal subject did in role physical (P < 0.01) and were better than normal subjects in vitality (P < 0.001) and mental health (P < 0.01). As a whole, amputees have higher in mental summary component of quality of life (P < 0.05) and lower in physical component of quality of life (P < 0.01). Conclusion: Diminishing the demand and improving social support of amputee veterans might be considered as high grade in mental summary component of their quality of life. PMID:23113210

Recurrent laryngeal nerve reinnervation for management of aspiration in a subset of children.

PubMed

Zur, Karen B; Carroll, Linda M

2018-01-01

Pediatric aspiration is a multifactorial process that is often complex to manage. Recurrent laryngeal nerve (RLN) injury can cause glottic insufficiency and aspiration. We describe three cases of unilateral vocal fold paralysis resulting in aspiration and the successful use of the RLN reinnervation for its treatment. The theory for utilizing the reinnervation procedure is that when glottic closure improves and a less breathy vocalization occurs, then the larynx is better equipped to protect the lower airway and avoid aspiration. Our cases demonstrate stronger voice and improved swallow function, with normalization of modified barium swallow evaluation, at approximately 6-months post reinnervation. Copyright © 2017. Published by Elsevier B.V.

Outcomes of Laryngeal Reinnervation for Unilateral Vocal Fold Paralysis in Children: Associations With Age and Time Since Injury.

PubMed

Smith, Marshall E; Houtz, Daniel R

2016-05-01

Outcomes of laryngeal reinnervation with ansa-cervicalis for unilateral vocal fold paralysis (UVFP) may be influenced by age of the patient and time interval between laryngeal nerve injury and reinnervation, suggesting less favorable outcomes in older patients and greater than 2-year time interval after injury. This study examines these issues in the pediatric population. Review of prospectively collected data set of 35 children and adolescents (1-21 years) that underwent ansa-recurrent laryngeal nerve (RLN) laryngeal reinnervation for UVFP. The time from RLN injury to reinnervation averaged 5.0 years (range, 0.8-15.2 years). No correlation was found between age at reinnervation (r = 0.15) and patient- or parent-reported global percentage voice outcome or perceptual ratings. There was slight negative correlation in duration between RLN injury and reinnervation and voice outcomes (r = -0.31). Postoperative voice self/surrogate global percentage rating average was 80.5% (range, 50%-100%), and perceptual rating GRBAS sum score average was 2.9 (range, 0-7). In pediatric ansa-RLN reinnervation for UVFP, no correlation between age at surgery and postoperative outcome was found. Denervation duration showed slight negative correlation, similar to what has been reported in adults, though voice improvement was seen in all patients. © The Author(s) 2015.

Evaluation of extreme learning machine for classification of individual and combined finger movements using electromyography on amputees and non-amputees.

PubMed

Anam, Khairul; Al-Jumaily, Adel

2017-01-01

The success of myoelectric pattern recognition (M-PR) mostly relies on the features extracted and classifier employed. This paper proposes and evaluates a fast classifier, extreme learning machine (ELM), to classify individual and combined finger movements on amputees and non-amputees. ELM is a single hidden layer feed-forward network (SLFN) that avoids iterative learning by determining input weights randomly and output weights analytically. Therefore, it can accelerate the training time of SLFNs. In addition to the classifier evaluation, this paper evaluates various feature combinations to improve the performance of M-PR and investigate some feature projections to improve the class separability of the features. Different from other studies on the implementation of ELM in the myoelectric controller, this paper presents a complete and thorough investigation of various types of ELMs including the node-based and kernel-based ELM. Furthermore, this paper provides comparisons of ELMs and other well-known classifiers such as linear discriminant analysis (LDA), k-nearest neighbour (kNN), support vector machine (SVM) and least-square SVM (LS-SVM). The experimental results show the most accurate ELM classifier is radial basis function ELM (RBF-ELM). The comparison of RBF-ELM and other well-known classifiers shows that RBF-ELM is as accurate as SVM and LS-SVM but faster than the SVM family; it is superior to LDA and kNN. The experimental results also indicate that the accuracy gap of the M-PR on the amputees and non-amputees is not too much with the accuracy of 98.55% on amputees and 99.5% on the non-amputees using six electromyography (EMG) channels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three-dimensional knee joint contact forces during walking in unilateral transtibial amputees.

PubMed

Silverman, Anne K; Neptune, Richard R

2014-08-22

Individuals with unilateral transtibial amputations have greater prevalence of osteoarthritis in the intact knee joint relative to the residual leg and non-amputees, but the cause of this greater prevalence is unclear. The purpose of this study was to compare knee joint contact forces and the muscles contributing to these forces between amputees and non-amputees during walking using forward dynamics simulations. We predicted that the intact knee contact forces would be higher than those of the residual leg and non-amputees. In the axial and mediolateral directions, the intact and non-amputee legs had greater peak tibio-femoral contact forces and impulses relative to the residual leg. The peak axial contact force was greater in the intact leg relative to the non-amputee leg, but the stance phase impulse was greater in the non-amputee leg. The vasti and hamstrings muscles in early stance and gastrocnemius in late stance were the largest contributors to the joint contact forces in the non-amputee and intact legs. Through dynamic coupling, the soleus and gluteus medius also had large contributions, even though they do not span the knee joint. In the residual leg, the prosthesis had large contributions to the joint forces, similar to the soleus in the intact and non-amputee legs. These results identify the muscles that contribute to knee joint contact forces during transtibial amputee walking and suggest that the peak knee contact forces may be more important than the knee contact impulses in explaining the high prevalence of intact leg osteoarthritis. Copyright © 2014 Elsevier Ltd. All rights reserved.

The utility of hand transplantation in hand amputee patients.

PubMed

Alolabi, Noor; Chuback, Jennifer; Grad, Sharon; Thoma, Achilles

2015-01-01

To measure the desirable health outcome, termed utility, and the expected quality-adjusted life years (QALYs) gained with hand composite tissue allotransplantation (CTA) using hand amputee patients and the general public. Using the standard gamble (SG) and time trade-off (TTO) techniques, utilities were obtained from 30 general public participants and 12 amputee patients. The health utility and net QALYs gained or lost with transplantation were computed. A sensitivity analysis was conducted to account for the effects of lifelong immunosuppression on the life expectancy of transplant recipients. Higher scores represent greater utility. Hand amputation mean health utility as measured by the SG and TTO methods, respectively, was 0.72 and 0.80 for the general public and 0.69 and 0.70 for hand amputees. In comparison, hand CTA mean health utility was 0.74 and 0.82 for the general public and 0.83 and 0.86 for amputees. Hand CTA imparted an expected gain of 0.9 QALYs (SG and TTO) in the general public and 7.0 (TTO) and 7.8 (SG) QALYs in hand amputees. A loss of at least 1.7 QALYs was demonstrated when decreasing the life expectancy in the sensitivity analysis in the hand amputee group. Hand amputee patients did not show a preference toward hand CTA with its inherent risks. With this procedure being increasingly adopted worldwide, the benefits must be carefully weighed against the risks of lifelong immunosuppressive therapy. This study does not show clear benefit to advocate hand CTA. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Local dynamic stability of lower extremity joints in lower limb amputees during slope walking.

PubMed

Chen, Jin-Ling; Gu, Dong-Yun

2013-01-01

Lower limb amputees have a higher fall risk during slope walking compared with non-amputees. However, studies on amputees' slope walking were not well addressed. The aim of this study was to identify the difference of slope walking between amputees and non-amputees. Lyapunov exponents λS was used to estimate the local dynamic stability of 7 transtibial amputees' and 7 controls' lower extremity joint kinematics during uphill and downhill walking. Compared with the controls, amputees exhibited significantly lower λS in hip (P=0.04) and ankle (P=0.01) joints of the sound limb, and hip joints (P=0.01) of the prosthetic limb during uphill walking, while they exhibited significantly lower λS in knee (P=0.02) and ankle (P=0.03) joints of the sound limb, and hip joints (P=0.03) of the prosthetic limb during downhill walking. Compared with amputees level walking, they exhibited significantly lower λS in ankle joints of the sound limb during both uphill (P=0.01) and downhill walking (P=0.01). We hypothesized that the better local dynamic stability of amputees was caused by compensation strategy during slope walking.

Factors Associated with Prosthetic Looseness in Lower Limb Amputees.

PubMed

Phonghanyudh, Thong; Sutpasanon, Taweesak; Hathaiareerug, Chanasak; Devakula, M L Buddhibongsa; Kumnerddee, Wipoo

2015-12-01

To determine the factors associated with prosthetic looseness in lower limb amputees in Sisaket province. The present was a cross-sectional descriptive study. Subjects were lower limb amputees who previously obtained prostheses and required prosthetic replacements at the mobile prosthetic laboratory unit under the Prostheses Foundation of H.R.H. the Princess Mother at Khun Han Hospital, Sisaket province, in February 2013. Data including participant characteristics, prosthetic looseness data, and various variables were collected by direct semi-structured interview. Energy expenditures in physical activities were measured using the Thai version of the short format international physical activity questionnaire. Data between participants with and without prosthetic looseness were compared to determine prosthetic loosening associated factors. Among 101 participants enrolled, 33 (32.7%) had prosthetic looseness with average onset of 1.76 ± 1.67 years. Diabetes mellitus was the only significant factor associated with prosthetic looseness from both univariate and multivariate analyses (HR = 7.05, p = 0.002 and HR = 5.93, p = 0.007 respectively). Among the lower limb amputees in Sisaket province, diabetes mellitus was the only factor associated with prosthetic looseness. Therefore, diabetic screening should be supplemented in lower limb amputee assessment protocol. In addition, we recommend that amputees with diabetes mellitus should receive prosthesis check out at approximately

An Evaluation of the Ability of Amputees to Operate Highway Transport Equipment. Final Report.

ERIC Educational Resources Information Center

McFarland, Ross A.; And Others

To document the driving experience of amputees and to test whether amputees differ from non-amputees in the operation of a simulated motor vehicle, related literature was reviewed, a comprehensive study of private motor vehicle operation by amputees was carried out, and 100 persons (20 non-impaired, non-commercial drivers, 20 non-impaired,…

BODY IMAGE, HOPELESSNESS AND PERSONALITY DIMENSIONS IN LOWER LIMB AMPUTEES

PubMed Central

Bhojak, M.M.; Nathawat, S.S.

1988-01-01

SUMMARY A sample of lower limb amputees and equal number of matched surgical controls was studied on body image, hopelessness and personality dimensions using Fisher's Body Distortion Questionnaire (BDQ). Beck's Hopelessness Scale and Hindi PEN Inventory. Amputees had significantly higher mean scores on body distortion (x 27.86), hopelessness (x 14.08) and neuroticism (x 9.30) as compared to surgical controls. Furthermore they had significantly lesser scores on extraversion (x 11.26) in comparison to their surgical counterparts. No significant differences were found on psychoticism in the two groups. Psychological aspects of amputation have not received much attention. By and large, amputees are believed to have more difficulty in dealing with people than things. It is the loss of ability to relate psychologically, socially, sexually and vocationally that inhibits the amputees most. PMID:21927302

Spontaneous laryngeal reinnervation following chronic recurrent laryngeal nerve injury.

PubMed

Kupfer, Robbi A; Old, Matthew O; Oh, Sang Su; Feldman, Eva L; Hogikyan, Norman D

2013-09-01

To enhance understanding of spontaneous laryngeal muscle reinnervation following severe recurrent laryngeal nerve injury by testing the hypotheses that 1) nerve fibers responsible for thyroarytenoid muscle reinnervation can originate from multiple sources and 2) superior laryngeal nerve is a source of reinnervation. Prospective, controlled, animal model. A combination of retrograde neuronal labeling techniques, immunohistochemistry, electromyography, and sequential observations of vocal fold mobility were employed in rat model of chronic recurrent laryngeal nerve injury. The current study details an initial set of experiments in sham surgical and denervated group animals and a subsequent set of experiments in a denervated group. At 3 months after recurrent laryngeal nerve resection, retrograde brainstem neuronal labeling identified cells in the characteristic superior laryngeal nerve cell body location as well as cells in a novel caudal location. Regrowth of neuron fibers across the site of previous recurrent laryngeal nerve resection was seen in 87% of examined animals in the denervated group. Electromyographic data support innervation by both the superior and recurrent laryngeal nerves following chronic recurrent laryngeal nerve injury. Following chronic recurrent laryngeal nerve injury in the rat, laryngeal innervation is demonstrated through the superior laryngeal nerve from cells both within and outside of the normal cluster of cells that supply the superior laryngeal nerve. The recurrent laryngeal nerve regenerates across a surgically created gap, but functional significance of regenerated nerve fibers is unclear. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Influence of Netrin-1 on reinnervation of laryngeal muscles following recurrent laryngeal nerve injury.

PubMed

Hernandez-Morato, Ignacio; Koss, Shira; Sharma, Sansar; Pitman, Michael J

2017-07-13

Following recurrent laryngeal nerve (RLN) injury, recovery results in poor functional restitution of the paralyzed vocal fold. Netrin-1 has been found to be upregulated in the rat posterior cricoarytenoid muscle (PCA) during nerve regeneration. We evaluated the effect of ectopic Netrin-1 in the PCA during RLN reinnervation. The right RLN was transected and Netrin-1 was injected into the PCA (2.5, 5, 10, 15, 20μg/ml). At 7 days post injury fluorescent retrograde tracer was injected into the PCA and Thyroarytenoid (TA) muscles. At 9 days tissues were harvested. Immunostaining showed reinnervation patterns in the laryngeal muscles and labelled motoneurons in the nucleus ambiguus. Lower concentrations of Netrin-1 (2.5 and 5μg/ml) showed no significant changes in laryngeal muscles reinnervation. Higher concentrations of Netrin-1 significantly reduced motor end plate innervation. The most effective dose was 10μg/ml showing reduced number of innervated motor endplates in the PCA. The somatotopic organization of the nucleus ambiguus was altered in all concentrations of Netrin-1 injection. These findings indicate that injection of Netrin-1 into the PCA changes the reinnervation pattern of the RLN. Copyright © 2017. Published by Elsevier B.V.

Mental health and satisfaction with life among upper limb amputees: a Norwegian population-based survey comparing adult acquired major upper limb amputees with a control group.

PubMed

Østlie, Kristin; Magnus, Per; Skjeldal, Ola H; Garfelt, Beate; Tambs, Kristian

2011-01-01

To assess how upper limb amputation affects mental health and life satisfaction. Cross-sectional study comparing the mental health and perceived satisfaction with life among adult acquired major upper limb amputees in Norway with a control group drawn from the Norwegian general population. The scales used were the Satisfaction With Life Scale (SWLS) and the Hopkins Symptom Check List 25-item (SCL-25). The groups were compared using multiple linear regression analyses. The amputees scored significantly lower on life satisfaction than the control group. A tendency to poorer mental health in the amputee group was observed, but there was no clear evidence of such a difference. The amputation effect on life satisfaction seemed to be mediated mainly by changes in occupational status and by the occurrence of short- or long-term complications related to the amputation. Our findings imply that rehabilitation of upper limb amputees should emphasise facilitating return to work as well as the prevention of short- and long-term complications, and that this will be of importance not only for the amputees' physical function, but for the maintenance of acceptable life satisfaction. Further studies on the effect of upper limb amputation on mental health are recommended.

Force recovery and axonal regeneration of the sternomastoid muscle reinnervated with the end-to-end nerve anastomosis

PubMed Central

Sobotka, Stanislaw; Mu, Liancai

2012-01-01

Background End-to-end nerve anastomosis (EEA) is a commonly used nerve repair technique. However, this method generally results in poor functional recovery. This study was designed to determine the correlation of functional recovery to the extent of axonal reinnervation after EEA procedure in a rat model. Materials and Methods Seven adult rats were subjected to the immediate reinnervation of an experimentally paralyzed sternomastoid (SM) muscle. The SM nerve was transected and immediately repaired with EEA. The SM muscle at the opposite side, without nerve transection, served as a control. Three months after EEA nerve repair, the muscle force of the SM muscle was measured and the regenerated axons in the muscle were detected using neurofilament immunohistochemistry. Results Three months after surgery, the reinnervated SM muscle produced limited anatomical and functional recovery (calculated as the percentage of the control). Specifically, the wet weight of the operated SM muscle (a measure of muscle mass recovery) was 78.0% of the control. The maximal tetanic force (a measure of muscle functional recovery) was 56.7% of the control. The area fraction of the neurofilament stained intramuscular axons (a measure of axonal regeneration and muscle reinnervation) was measured to be only 13.4% of the control. A positive correlation was revealed between the extent of muscle reinnervation and maximal muscle force. Conclusions The EEA reinnervated SM muscle in the rat yielded unsatisfactory muscle force recovery as a result of mild to moderate nerve regeneration. Further work is needed to improve the surgical procedure, enhance axonal regeneration, and/or develop novel treatment strategies for better functional recovery. PMID:23207170

Force recovery and axonal regeneration of the sternomastoid muscle reinnervated with the end-to-end nerve anastomosis.

PubMed

Sobotka, Stanislaw; Mu, Liancai

2013-06-15

End-to-end nerve anastomosis (EEA) is a commonly used nerve repair technique. However, this method generally results in poor functional recovery. This study was designed to determine the correlation of functional recovery to the extent of axonal reinnervation after EEA procedure in a rat model. Seven adult rats were subjected to the immediate reinnervation of an experimentally paralyzed sternomastoid (SM) muscle. The SM nerve was transected and immediately repaired with EEA. The SM muscle at the opposite side, without nerve transection, served as a control. Three months after EEA nerve repair, the muscle force of the SM muscle was measured and the regenerated axons in the muscle were detected using neurofilament immunohistochemistry. Three months after surgery, the reinnervated SM muscle produced limited anatomical and functional recovery (calculated as the percentage of the control). Specifically, the wet weight of the operated SM muscle (a measure of muscle mass recovery) was 78.0% of the control. The maximal tetanic force (a measure of muscle functional recovery) was 56.7% of the control. The area fraction of the neurofilament stained intramuscular axons (a measure of axonal regeneration and muscle reinnervation) was measured to be only 13.4% of the control. A positive correlation was revealed between the extent of muscle reinnervation and maximal muscle force. The EEA reinnervated SM muscle in the rat yielded unsatisfactory muscle force recovery as a result of mild to moderate nerve regeneration. Further work is needed to improve the surgical procedure, enhance axonal regeneration, and/or develop novel treatment strategies for better functional recovery. Copyright © 2013 Elsevier Inc. All rights reserved.

Kinematic differences exist between transtibial amputee fallers and non-fallers during downwards step transitioning.

PubMed

Vanicek, Natalie; Strike, Siobhán C; Polman, Remco

2015-08-01

Stair negotiation is biomechanically more challenging than level gait. There are few biomechanical assessments of transtibial amputees descending stairs and none specifically related to falls. Stair descent may elicit more differences than level gait in amputees with and without a previous falls history. The aim of this study was to compare the gait kinematics of fallers and non-fallers during downwards step transitioning in transtibial amputees. Cross-sectional study. Six fallers and five non-fallers completed step transition trials on a three-step staircase at their self-selected pace. Nine participants exhibited a clear preference to lead with the affected limb, while two had no preference. Four participants self-selected a step-to rather than a reciprocal stair descent strategy. The fallers who used a reciprocal strategy walked 44% more quickly than the non-fallers. To compensate for the lack of active plantar flexion of the prosthetic foot, exaggerated range of motion occurred proximally at the pelvis during swing. The step-to group was more reliant on the handrails than the reciprocal group and walked more slowly. As anticipated, the fallers walked faster than the non-fallers despite employing the more difficult 'roll-over' technique. Handrail use could help to improve dynamic control during downwards step transitions. Transtibial amputees are advised to descend steps using external support, such as handrails, for enhanced dynamic control. Hip abductor and knee extensor eccentric strength should be improved through targeted exercise. Prosthetic socket fit should be checked to allow adequate knee range of motion on the affected side. © The International Society for Prosthetics and Orthotics 2014.

Comparison of muscles activity of abled bodied and amputee subjects for around shoulder movement.

PubMed

Kaur, Amanpreet; Agarwal, Ravinder; Kumar, Amod

2016-05-12

Worldwide, about 56% of the amputees are upper limb amputees. This research deals a method with two-channel surface electromyogram (SEMG) signal recorded from around shoulder to estimate the changes in muscle activity in non-amputee and the residual limb of trans humeral amputees with different movements of arm. Identification of different muscles activity of near shoulder amputee and non-amputee persons. SEMG signal were acquired during three distinct exercises from three-selected muscles location around shoulder. The participants were asked to move their dominant arm from an assigned position to record their muscles activity recorded with change in position. Results shows the muscles activity in scalene is more than the other muscles like pectoralis and infraspinatus with the same shoulder motion. In addition, STFT (Short-Time Fourier Transform) spectrogram with window length of 256 samples at maximum of 512 frequency bins using hamming window has used to identify the signal for the maximum muscles activity with best resolution in spectrum plot. The results suggest that one can use this analysis for making a suitable device for around shoulder prosthetic users based on muscles activation of amputee persons.

Restoration of quinine-stimulated Fos-immunoreactive neurons in the central nucleus of the amygdala and gustatory cortex following reinnervation or cross-reinnervation of the lingual taste nerves in rats.

PubMed

King, Camille Tessitore; Garcea, Mircea; Spector, Alan C

2014-08-01

Remarkably, when lingual gustatory nerves are surgically rerouted to inappropriate taste fields in the tongue, some taste functions recover. We previously demonstrated that quinine-stimulated oromotor rejection reflexes and neural activity (assessed by Fos immunoreactivity) in subregions of hindbrain gustatory nuclei were restored if the posterior tongue, which contains receptor cells that respond strongly to bitter compounds, was cross-reinnervated by the chorda tympani nerve. Such functional recovery was not seen if instead, the anterior tongue, where receptor cells are less responsive to bitter compounds, was cross-reinnervated by the glossopharyngeal nerve, even though this nerve typically responds robustly to bitter substances. Thus, recovery depended more on the taste field being reinnervated than on the nerve itself. Here, the distribution of quinine-stimulated Fos-immunoreactive neurons in two taste-associated forebrain areas was examined in these same rats. In the central nucleus of the amygdala (CeA), a rostrocaudal gradient characterized the normal quinine-stimulated Fos response, with the greatest number of labeled cells situated rostrally. Quinine-stimulated neurons were found throughout the gustatory cortex, but a "hot spot" was observed in its anterior-posterior center in subregions approximating the dysgranular/agranular layers. Fos neurons here and in the rostral CeA were highly correlated with quinine-elicited gapes. Denervation of the posterior tongue eliminated, and its reinnervation by either nerve restored, numbers of quinine-stimulated labeled cells in the rostralmost CeA and in the subregion approximating the dysgranular gustatory cortex. These results underscore the remarkable plasticity of the gustatory system and also help clarify the functional anatomy of neural circuits activated by bitter taste stimulation. © 2014 Wiley Periodicals, Inc.

Recurrent laryngeal nerve regeneration through a silicone tube produces reinnervation without vocal fold mobility in rats.

PubMed

Kumai, Yoshihiko; Aoyama, Takashi; Nishimoto, Kohei; Sanuki, Tetsuji; Minoda, Ryosei; Yumoto, Eiji

2013-01-01

We established an animal model of recurrent laryngeal nerve reinnervation with persistent vocal fold immobility following recurrent laryngeal nerve injury. In 36 rats, the left recurrent laryngeal nerve was transected and the stumps were abutted in a silicone tube with a 1-mm interspace, facilitating regeneration. The mobility of the vocal folds was examined endoscopically 5, 10, and 15 weeks later. Electromyography of the thyroarytenoid muscle was performed. Reinnervation was assessed by means of a quantitative immunohistologic evaluation with anti-neurofilament antibody in the nerve both proximal and distal to the silicone tube. The atrophy of the thyroarytenoid muscle was assessed histologically. We observed that all animals had a fixed left vocal fold throughout the study. The average neurofilament expression in the nerve both distal and proximal to the silicone tube, the muscle area, and the amplitude of the compound muscle action potential recorded from the thyroarytenoid muscle on the treated side increased significantly (p < 0.05) over time, demonstrating regeneration through the silicone tube. Recurrent laryngeal nerve regeneration through a silicone tube produced reinnervation without vocal fold mobility in rats. The efficacy of new laryngeal reinnervation treatments can be assessed with this model.

Effects of diabetic peripheral neuropathy on gait in vascular trans-tibial amputees.

PubMed

Nakajima, Hiroshi; Yamamoto, Sumiko; Katsuhira, Junji

2018-07-01

Patients with diabetes often develop diabetic peripheral neuropathy, which is a distal symmetric polyneuropathy, so foot function on the non-amputated side is expected to affect gait in vascular trans-tibial amputees. However, there is little information on the kinematics and kinetics of gait or the effects of diabetic peripheral neuropathy in vascular trans-tibial amputees. This study aimed to clarify these effects, including the biomechanics of the ankle on the non-amputated side. Participants were 10 vascular trans-tibial amputees with diabetic peripheral neuropathy (group V) and 8 traumatic trans-tibial amputees (group T). Each subject's gait was analyzed at a self-selected speed using a three-dimensional motion analyzer and force plates. Ankle plantarflexion angle, heel elevation angle, and peak and impulse of anterior ground reaction force were smaller on the non-amputated side during pre-swing in group V than in group T. Center of gravity during pre-swing on the non-amputated side was lower in group V than in group T. Hip extension torque during loading response on the prosthetic side was greater in group V than in group T. These findings suggest that the biomechanical function of the ankle on the non-amputated side during pre-swing is poorer in vascular trans-tibial amputees with DPN than in traumatic trans-tibial amputees; the height of the center of gravity could not be maintained during this phase in vascular trans-tibial amputees with diabetic peripheral neuropathy. The hip joint on the prosthetic side compensated for this diminished function at the ankle during loading response. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of evoked tactile sensation in forearm amputees with transcutaneous electrical nerve stimulation

NASA Astrophysics Data System (ADS)

Chai, Guohong; Sui, Xiaohong; Li, Si; He, Longwen; Lan, Ning

2015-12-01

Objective. The goal of this study is to characterize the phenomenon of evoked tactile sensation (ETS) on the stump skin of forearm amputees using transcutaneous electrical nerve stimulation (TENS). Approach. We identified the projected finger map (PFM) of ETS on the stump skin in 11 forearm amputees, and compared perceptual attributes of the ETS in nine forearm amputees and eight able-bodied subjects using TENS. The profile of perceptual thresholds at the most sensitive points (MSPs) in each finger-projected area was obtained by modulating current amplitude, pulse width, and frequency of the biphasic, rectangular current stimulus. The long-term stability of the PFM and the perceptual threshold of the ETS were monitored in five forearm amputees for a period of 11 months. Main results. Five finger-specific projection areas can be independently identified on the stump skin of forearm amputees with a relatively long residual stump length. The shape of the PFM was progressively similar to that of the hand with more distal amputation. Similar sensory modalities of touch, pressure, buzz, vibration, and numb below pain sensation could be evoked both in the PFM of the stump skin of amputees and in the normal skin of able-bodied subjects. Sensory thresholds in the normal skin of able-bodied subjects were generally lower than those in the stump skin of forearm amputees, however, both were linearly modulated by current amplitude and pulse width. The variation of the MSPs in the PFM was confined to a small elliptical area with 95% confidence. The perceptual thresholds of thumb-projected areas were found to vary less than 0.99 × 10-2 mA cm-2. Significance. The stable PFM and sensory thresholds of ETS are desirable for a non-invasive neural interface that can feed back finger-specific tactile information from the prosthetic hand to forearm amputees.

Localizing and Assessing Amputee Pain with Intense Focused Ultrasound

DTIC Science & Technology

2016-10-01

the nerve and then implants it into nearby muscle. TMR surgery has anecdotal evidence of reduced pain for amputees relative to standard amputee...Neuropathic Pain Is Present in Chronic Low Back Pain and Soft Tissue Syndromes? An Evidence - Based Structured Review. Pain Med. 2014 Jan 1;15(1):4–15...scar tissue at the end of cut nerves that then applies pressure to the nerve ending. In addition, traditional amputation surgery almost always produces

The effects of laterality on obstacle crossing performance in unilateral trans-tibial amputees.

PubMed

De Asha, Alan R; Buckley, John G

2015-05-01

Unilateral trans-tibial amputees have bilaterally reduced toe clearance, and an increased risk of foot contact, while crossing obstacles compared to the able-bodied. While the able-bodied tend to lead with a 'preferred' limb it is equivocal whether amputees prefer to lead with the intact or prosthetic limb. This study determined the effects of laterality, compared to side of amputation, on amputees' obstacle crossing performance. To help understand why laterality could affect performance we also assessed knee proprioception for both limbs. Foot placement and toe clearance parameters were recorded while nine amputees crossed obstacles of varying heights leading with both their intact and prosthetic limbs. Joint-position sense was also assessed. Participants self-reported which limb was their preferred (dominant) limb. There were no significant differences in foot placements or toe clearance variability across lead-limb conditions. There were no significant differences in toe clearance between intact and prosthetic lead-limbs (p=0.28) but toe clearance was significantly higher when amputees led with their preferred compared to non-preferred limb (p=0.025). There was no difference in joint-position sense between the intact and residual knees (p=0.34) but joint-position sense tended to be more accurate for the preferred, compared to non-preferred limb (p=0.08). Findings suggest that, despite the mechanical constraints imposed by use of a prosthesis, laterality may be as important in lower-limb amputees as it is in the able bodied. This suggests that amputees should be encouraged to cross obstacles leading with their preferred limb. Copyright © 2015. Published by Elsevier Ltd.

Survival rates in dysvascular lower limb amputees.

PubMed

Kulkarni, J; Pande, S; Morris, J

2006-01-01

To assess the 5-year and 10-year survival rates of major (above ankle disarticulation level) dysvascular lower limb amputees attending a sub-regional Disablement Services Centre (DSC) specialising in amputee rehabilitation. Also to investigate the association between survival rates, cause of dysvascularity, level of amputation, smoking status and occupational status. The study was undertaken in sub-regional DSC for amputee rehabilitation covering a base population of about 3.5million people. Over 80% of lower limb amputations were done for dysvascularity (peripheral vascular disease, diabetic or combination). All these patients were followed up in the DSC for their prosthetic/amputee rehabilitation. Modular case records of 201 consecutive patients from 1994 to 1995 who had diagnosis of dysvascularity as the cause of major lower limb amputations, were scrutinised regarding their 10-year survival; demographic details, level of lower limb amputations, Above Knee (AK=Transfemoral), Below Knee (BK=Transtibial), smoking status, occupational status, healing of the stump at first assessment, cause of amputation and association of these factors with survival rates. Of 201 individuals with either AK or BK amputations, 60% (121) had AK amputations and 67% (134) were males, the mean age was 69years of age. Sixty-seven percent (97) had history of smoking, either current 43% (62) or prior 24% (35) smoking, and 59% (68) were skilled or non-skilled manual workers. Fifty-one percent (99) had diagnosis of peripheral vascular disease, whilst 34% (65) had combination of peripheral vascular disease and diabetes, diabetes on its own in 4% (7). In 12% (23) other causes were noted such as embolism, acute ischaemia, venous ulcers, etc. Regarding stumps healing at first assessment, healing was noted in 54% (109) whilst stump was unhealed in 46% (92). The median survival was 48months. Using Cox proportional hazards regression to identify association with survival, the hazard ratio (HR) was

Piezoelectric Bimorphs' Characteristics as In-Socket Sensors for Transfemoral Amputees

PubMed Central

El-Sayed, Amr M.; Hamzaid, Nur Azah; Osman, Noor Azuan Abu

2014-01-01

Alternative sensory systems for the development of prosthetic knees are being increasingly highlighted nowadays, due to the rapid advancements in the field of lower limb prosthetics. This study presents the use of piezoelectric bimorphs as in-socket sensors for transfemoral amputees. An Instron machine was used in the calibration procedure and the corresponding output data were further analyzed to determine the static and dynamic characteristics of the piezoelectric bimorph. The piezoelectric bimorph showed appropriate static operating range, repeatability, hysteresis, and frequency response for application in lower prosthesis, with a force range of 0–100 N. To further validate this finding, an experiment was conducted with a single transfemoral amputee subject to measure the stump/socket pressure using the piezoelectric bimorph embedded inside the socket. The results showed that a maximum interface pressure of about 27 kPa occurred at the anterior proximal site compared to the anterior distal and posterior sites, consistent with values published in other studies. This paper highlighted the capacity of piezoelectric bimorphs to perform as in-socket sensors for transfemoral amputees. However, further experiments are recommended to be conducted with different amputees with different socket types. PMID:25513823

Determinants of skin problems of the stump in lower-limb amputees.

PubMed

Meulenbelt, Henk E; Geertzen, Jan H; Jonkman, Marcel F; Dijkstra, Pieter U

2009-01-01

To identify determinants of skin problems in lower-limb amputees. Survey, using a questionnaire. Not applicable. Lower-limb amputees (N=2039) who either obtained their prosthesis through the Orthopedische Instrument Makerij (a group of orthopedic workshops in the Netherlands) or were a member of the (Dutch) National Society of Amputees (Landelijke Vereniging van Geamputeerden) were invited to participate. In total, 872 lower-limb amputees agreed to participate. Amputees filled in the questionnaire to assess characteristics of the amputation and prosthesis, level of activity, stump and prosthesis hygiene, and skin problems. Stepwise backward logistic regression was performed to analyze determinants of skin problems. Skin problems in the month prior to completing the questionnaire. A total of 816 questionnaires were received. Eventually 805 questionnaires were suitable for statistical analysis. Protective determinants were (in order of magnitude of association) older age, male sex, and amputation because of peripheral arterial disease and/or diabetes. Provocative determinants were (in order of magnitude of association) use of antibacterial soap, smoking, and washing the stump 4 times a week or more often. In total, 63% of the participants (95% confidence interval, 60%-67%) reported 1 or more skin problems. The provocative determinants identified in this study--use of antibacterial soap, smoking, and stump washing frequency--have to be studied for their clinical relevance.

Renal sensory and sympathetic nerves reinnervate the kidney in a similar time-dependent fashion after renal denervation in rats

PubMed Central

Mulder, Jan; Hökfelt, Tomas; Knuepfer, Mark M.

2013-01-01

Efferent renal sympathetic nerves reinnervate the kidney after renal denervation in animals and humans. Therefore, the long-term reduction in arterial pressure following renal denervation in drug-resistant hypertensive patients has been attributed to lack of afferent renal sensory reinnervation. However, afferent sensory reinnervation of any organ, including the kidney, is an understudied question. Therefore, we analyzed the time course of sympathetic and sensory reinnervation at multiple time points (1, 4, and 5 days and 1, 2, 3, 4, 6, 9, and 12 wk) after renal denervation in normal Sprague-Dawley rats. Sympathetic and sensory innervation in the innervated and contralateral denervated kidney was determined as optical density (ImageJ) of the sympathetic and sensory nerves identified by immunohistochemistry using antibodies against markers for sympathetic nerves [neuropeptide Y (NPY) and tyrosine hydroxylase (TH)] and sensory nerves [substance P and calcitonin gene-related peptide (CGRP)]. In denervated kidneys, the optical density of NPY-immunoreactive (ir) fibers in the renal cortex and substance P-ir fibers in the pelvic wall was 6, 39, and 100% and 8, 47, and 100%, respectively, of that in the contralateral innervated kidney at 4 days, 4 wk, and 12 wk after denervation. Linear regression analysis of the optical density of the ratio of the denervated/innervated kidney versus time yielded similar intercept and slope values for NPY-ir, TH-ir, substance P-ir, and CGRP-ir fibers (all R2 > 0.76). In conclusion, in normotensive rats, reinnervation of the renal sensory nerves occurs over the same time course as reinnervation of the renal sympathetic nerves, both being complete at 9 to 12 wk following renal denervation. PMID:23408032

Atypical electrophysiological activity during pain observation in amputees who experience synaesthetic pain.

PubMed

Fitzgibbon, Bernadette M; Enticott, Peter G; Giummarra, Melita J; Thomson, Richard H; Georgiou-Karistianis, Nellie; Bradshaw, John L

2012-03-01

There are increasing reports of people experiencing pain when observing pain in another. This describes the phenomenon of synaesthetic pain which, until recently, had been primarily reported in amputees with phantom pain. In the current study, we used electroencephalography (EEG) to investigate how amputees who experience synaesthetic pain process pain observed in another. Participants were grouped according to amputees who experience phantom and synaesthetic pain (n=8), amputees who experience phantom pain but not synaesthetic pain (n=10) and healthy controls (n=10). Participants underwent EEG as they observed still images of hands and feet in potentially painful and non-painful situations. We found that pain synaesthetes showed some reduced event-related potential (ERP) components at certain electrode sites, and reduced theta- and alpha band power amplitude at a central electrode. The finding of reduced ERP amplitude and theta band power may reflect inhibition of the processing of observed pain (e.g. avoidance/guarding as a protective strategy), and reduced alpha band power may indicate a disinhibition in control processes that may result in synaesthetic pain. These results provide the first documentation of atypical neurophysiological activity in amputees who experience synaesthetic pain when processing pain in another. © The Author (2011). Published by Oxford University Press.

Management of the multiple limb amputee.

PubMed

Davidson, J H; Jones, L E; Cornet, J; Cittarelli, T

2002-09-10

Multiple limb amputations involving at least one upper extremity are very uncommon. The amputation of both an upper and lower limb is even more uncommon. Due to the rarity of these amputations therapists are uncertain regarding the most appropriate treatment methods. While the majority of the protocols used for single limb amputations are appropriate for these multiple limb amputees, there are differences. Loss of multiple limbs creates a problem of overheating for the individual. Loss of an arm and leg results in difficulty donning the prostheses and difficulty using crutches and parallel bars during mobilization. A review is given of 16 multiple limb amputees seen in our rehabilitation centre in the last 15 years. Return to work was seen in one third and was not related to the number of the amputations. A higher proportion of these multiple limb amputations occur through alcoholism or attempted suicide behaviour than occurs with either single upper limb amputations or lower limb amputations. This existing behaviour can create a management problem for the rehabilitation team during rehabilitation. Guidelines as to appropriate prosthetic and preprosthetic care are provided to assist the practitioner who has the acute and long term care of these patients. All multiple limb amputees should be referred to a specialized rehabilitation centre to discuss prosthetic options and long term rehabilitation requirements. This paper does not discuss bilateral lower limb amputations when not combined with an upper limb amputation.

Studying Upper-Limb Amputee Prosthesis Use to Inform Device Design

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-14-1-0277 TITLE: Studying Upper-Limb Amputee Prosthesis Use to Inform Device Design PRINCIPAL INVESTIGATOR: Aaron...Department of the Army position, policy or decision unless so designated by other documentation. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704...Amputee Prosthesis Use to Inform Device Design 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Aaron Dollar, Adam Spiers

Understanding adaptive gait in lower-limb amputees: insights from multivariate analyses

PubMed Central

2013-01-01

Background In this paper we use multivariate statistical techniques to gain insights into how adaptive gait involving obstacle crossing is regulated in lower-limb amputees compared to able-bodied controls, with the aim of identifying underlying characteristics that differ between the two groups and consequently highlighting gait deficits in the amputees. Methods Eight unilateral trans-tibial amputees and twelve able-bodied controls completed adaptive gait trials involving negotiating various height obstacles; with amputees leading with their prosthetic limb. Spatiotemporal variables that are regularly used to quantify how gait is adapted when crossing obstacles were determined and subsequently analysed using multivariate statistical techniques. Results and discussion There were fundamental differences in the adaptive gait between the two groups. Compared to controls, amputees had a reduced approach velocity, reduced foot placement distance before and after the obstacle and reduced foot clearance over it, and reduced lead-limb knee flexion during the step following crossing. Logistic regression analysis highlighted the variables that best distinguished between the gait of the two groups and multiple regression analysis (with approach velocity as a controlling factor) helped identify what gait adaptations were driving the differences seen in these variables. Getting closer to the obstacle before crossing it appeared to be a strategy to ensure the heel of the lead-limb foot passed over the obstacle prior to the foot being lowered to the ground. Despite adopting such a heel clearance strategy, the lead-foot was positioned closer to the obstacle following crossing, which was likely a result of a desire to attain a limb/foot angle and orientation at instant of landing that minimised loads on the residuum (as evidenced by the reduced lead-limb knee flexion during the step following crossing). These changes in foot placement meant the foot was in a different part of swing

Incidence and morbidity of concomitant spine fractures in combat-related amputees.

PubMed

Bevevino, Adam J; Lehman, Ronald A; Tintle, Scott M; Kang, Daniel G; Dworak, Theodora C; Potter, Benjamin K

2014-04-01

High-energy blasts are the most frequent cause of combat-related amputations in Operations Iraqi and Enduring Freedom (OIF/OEF). The nondiscriminating effects of this mechanism often result in both appendicular and axial skeletal injuries. Despite this recognized coincident injury pattern, the incidence and consequence of spine fractures in trauma-related combat amputees are unknown. This study sought to determine the incidence and morbidity of the associated spine fractures on patients with traumatic lower extremity amputation sustained during OIF/OEF. Retrospective case control. Two hundred twenty-six combat-related lower extremity amputees presenting to a single institution and injured between 2003 and 2008 were included for analysis. Physiologic and functional outcome measures were used to determine the influence of spine fractures on combat amputees. Physiologic measures included intensive care unit (ICU) admission rates, injury severity score (ISS), rate of narcotic/neuropathic pain use, and heterotopic ossification (HO) rates. Functional outcome measures included return-to-duty rates and ambulatory status at final follow-up. Data from 300 consecutive combat-related lower extremity amputations were retrospectively reviewed and grouped. Group 1 consisted of amputees with associated spine fractures, and Group 2 consisted of amputees without spine fractures. The results of the two groups were compared with regard to initial presentation and final functional outcomes. A total of 226 patients sustained 300 lower extremity amputations secondary to combat-related injuries, the most common mechanism being an improvised explosive device. Twenty-nine of these patients had a spine fracture (13%). Group 1 had a higher ISS than Group 2 (30 vs. 19, p<.001). Group 1 patients were also more likely to be admitted to the ICU (86% vs. 46%, p<.001). Furthermore, Group 1 patients had a significantly higher rate of HO in their residual limbs (82% vs. 55%, p<.005). The incidence of

An interim prosthesis program for lower limb amputees: comparison of public and private models of service.

PubMed

Gordon, Robert; Magee, Christopher; Frazer, Anna; Evans, Craig; McCosker, Kathryn

2010-06-01

This study compared the outcomes of an interim mechanical prosthesis program for lower limb amputees operated under a public and private model of service. Over a two-year period, 60 transtibial amputees were fitted with an interim prosthesis as part of their early amputee care. Thirty-four patients received early amputee care under a public model of service, whereby a prosthetist was employed to provide the interim mechanical prosthesis service. The remaining 26 patients received early amputee care under a private model of service, where an external company was contracted to provide the interim mechanical prosthesis service. The results suggested comparable clinical outcomes between the two patient groups. However, the public model appeared to be less expensive with the average labour cost per patient being 29.0% lower compared with the private model. The results suggest that a public model of service may provide a more comprehensive and less expensive interim prosthesis program for lower limb amputees.

Reinnervation of the lateral gastrocnemius and soleus muscles in the rat by their common nerve.

PubMed Central

Gillespie, M J; Gordon, T; Murphy, P R

1986-01-01

To determine whether there is any specificity of regenerating nerves for their original muscles, the common lateral gastrocnemius soleus nerve (l.g.s.) innervating the fast-twitch lateral gastrocnemius (l.g.) and slow-twitch soleus muscles was sectioned in the hind limb of twenty adult rats. The proximal nerve stump was sutured to the dorsal surface of the l.g. muscle and 4-14 months later, the contractile properties of the reinnervated l.g. and soleus muscles and their single motor units were studied by dissection and stimulation of the ventral root filaments. Contractile properties of normal contralateral muscles were examined for comparison and motor units were isolated in l.g. and soleus muscles for study in a group of untreated animals. Measurement of time and rate parameters of maximal twitch and tetanic contractions showed that the rate of development of force increased significantly in reinnervated soleus muscles and approached the speed of l.g. muscles but rate of relaxation did not change appreciably. In reinnervated l.g. muscles, contraction speed was similar to normal l.g. muscles but relaxation rate declined toward the rates of relaxation in control soleus muscles. After reinnervation by the common l.g.s. nerve, the proportion of slow motor units in l.g. increased from 10 to 31% and decreased in soleus from 80 to 31%. The relative proportions of fast and slow motor units in each muscle were the same as the proportions of fast and slow units in the normal l.g. and soleus muscles combined. It was concluded that fast and slow muscles do not show any preference for their former nerves and that the change in the force profile of the reinnervated muscles is indicative of the relative proportions of fast and slow motor units: fast units dominate the contraction phase and slow units the relaxation phase of twitch and tetanic contractions of the muscle. PMID:3723414

Observation-based training for neuroprosthetic control of grasping by amputees.

PubMed

Agashe, Harshavardhan A; Contreras-Vidal, Jose L

2014-01-01

Current brain-machine interfaces (BMIs) allow upper limb amputees to position robotic arms with a high degree of accuracy, but lack the ability to control hand pre-shaping for grasping different objects. We have previously shown that low frequency (0.1-1 Hz) time domain cortical activity recorded at the scalp via electroencephalography (EEG) encodes information about grasp pre-shaping. To transfer this technology to clinical populations such as amputees, the challenge lies in constructing BMI models in the absence of overt training hand movements. Here we show that it is possible to train BMI models using observed grasping movements performed by a robotic hand attached to amputees' residual limb. Three transradial amputees controlled the grasping motion of an attached robotic hand via their EEG, following the action-observation training phase. Over multiple sessions, subjects successfully grasped the presented object (a bottle or a credit card) in 53±16 % of trials, demonstrating the validity of the BMI models. Importantly, the validation of the BMI model was through closed-loop performance, which demonstrates generalization of the model to unseen data. These results suggest `mirror neuron system' properties captured by delta band EEG that allows neural representation for action observation to be used for action control in an EEG-based BMI system.

The influence of L-acetylcarnitine on reinnervation of the oculomotor nerve.

PubMed

Pettorossi, V E; Draicchio, F; Fernandez, E; Pallini, R

1993-01-01

In guinea-pigs the oral administration of L-acetylcarnitine (L-AC) markedly favours the process of reinnervation of the oculomotor nerve sectioned at intracranial level. The gains of the horizontal and vertical vestibulo-ocular reflexes (HVOR, VVOR) were taken into consideration in testing the functional recovery of the nerve. As a consequence of the drug administration, 24 weeks after the operation the gains of the treated animals were higher than those of the controls. Reduction of misalignments of the stimulus-response orientation was also observed in treated animals as compared to the controls. This suggests that L-AC potentiates motor reinnervation by enhancing the nerve-growing processes and favouring a better consolidation of the appropriate neuromuscular synapses. The increased gain, and the improvement of the alignment in ocular responses, due to L-AC would allow for an increase of visual function during head movement by optimizing gaze stability.

Lower-limb amputee ankle and hip kinetic response to an imposed error in mediolateral foot placement.

PubMed

Segal, Ava D; Shofer, Jane B; Klute, Glenn K

2015-11-26

Maintaining balance while walking is challenging for lower limb amputees. The effect of prosthetic foot stiffness on recovery kinetics from an error in foot placement may inform prescription practice and lead to new interventions designed to improve balance. Ten unilateral transtibial amputees were fit with two prosthetic feet with different stiffness properties in random order. After a 3-week acclimation period, they returned to the lab for testing before switching feet. Twelve non-amputees also participated in a single data collection. While walking on an instrumented treadmill, we imposed a repeatable, unexpected medial or lateral disturbance in foot placement by releasing a burst of air at the ankle just before heel strike. Three-dimensional motion capture, ground reaction force and center of pressure (COP) data were collected for two steps prior, the disturbed step and three steps after the disturbance. During undisturbed walking, coronal ankle impulse was lower by 42% for amputees wearing a stiff compared to a compliant foot (p=0.017); however, across steps, both prosthetic recovery patterns were similar compared to the sound limb and non-amputees. Peak coronal hip moment was 15-20% lower for both foot types during undisturbed walking (p<0.001), with less change in response to the medial disturbance (p<0.001) compared to the sound limb and non-amputees. Amputee prosthetic COP excursion was unaffected by the disturbance (2.4% change) compared to the sound limb (59% change; p<0.001) and non-amputees (55% change; p<0.001). These findings imply that a prosthetic foot-ankle system able to contribute to ankle kinetics may improve walking balance among amputees. Published by Elsevier Ltd.

Analysis and evaluation of functional status of lower extremity amputee-appliance systems: an integrated approach.

PubMed

Ganguli, S

1976-11-01

This paper introduces an integrated, objective and biomechanically sound approach for the analysis and evaluation of the functional status of lower extremity amputee-appliance systems. The method is demonstrated here in its application to the unilateral lower extremity amputee-axillary crutches system and the unilateral below-knee amputee-PTB prosthesis system, both of which are commonly encountered in day-to-day rehabilitation practice.

Reinnervation of Bilateral Posterior Cricoarytenoid Muscles Using the Left Phrenic Nerve in Patients with Bilateral Vocal Fold Paralysis

PubMed Central

Zheng, Hongliang; Chen, Donghui; Zhu, Minhui; Wang, Wei; Liu, Fei; Zhang, Caiyun

2013-01-01

Objective To evaluate the feasibility, effectiveness, and safety of reinnervation of the bilateral posterior cricoarytenoid (PCA) muscles using the left phrenic nerve in patients with bilateral vocal fold paralysis. Methods Forty-four patients with bilateral vocal fold paralysis who underwent reinnervation of the bilateral PCA muscles using the left phrenic nerve were enrolled in this study. Videostroboscopy, perceptual evaluation, acoustic analysis, maximum phonation time, pulmonary function testing, and laryngeal electromyography were performed preoperatively and postoperatively. Patients were followed-up for at least 1 year after surgery. Results Videostroboscopy showed that within 1 year after reinnervation, abductive movement could be observed in the left vocal folds of 87% of patients and the right vocal folds of 72% of patients. Abductive excursion on the left side was significantly larger than that on the right side (P < 0.05); most of the vocal function parameters were improved postoperatively compared with the preoperative parameters, albeit without a significant difference (P > 0.05). No patients developed immediate dyspnea after surgery, and the pulmonary function parameters recovered to normal reference value levels within 1 year. Postoperative laryngeal electromyography confirmed successful reinnervation of the bilateral PCA muscles. Eighty-seven percent of patients in this series were decannulated and did not show obvious dyspnea after physical activity. Those who were decannulated after subsequent arytenoidectomy were not included in calculating the success rate of decannulation. Conclusions Reinnervation of the bilateral PCA muscles using the left phrenic nerve can restore inspiratory vocal fold abduction to a physiologically satisfactory extent while preserving phonatory function at the preoperative level without evident morbidity. PMID:24098581

Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

PubMed

Lura, Derek J; Wernke, Matthew W; Carey, Stephanie L; Kahle, Jason T; Miro, Rebecca M; Highsmith, M Jason

2017-10-01

This study was a randomized crossover of stair ambulation of Transfemoral Amputees (TFAs) using the Genium and C-Leg prosthetic knees. TFAs typically have difficulty ascending and descending stairs, limiting community mobility. The objective of this study was to determine the relative efficacy of the Genium and C-Leg prostheses for stair ascent and descent, and their absolute efficacy relative to non-amputees. Twenty TFAs, and five non-amputees participated in the study. TFAs were randomized to begin the study with the Genium or C-Leg prosthesis. Informed consent was obtained from all participants prior to data collection and the study was listed on clinicaltrials.gov (#NCT01473662). After fitting, accommodation, and training, participants were asked to demonstrate their preferred gait pattern for stair ascent and descent and a step-over-step pattern if able. TFAs then switched prosthetic legs and repeated fitting, accommodation, training, and testing. An eight camera Vicon optical motion analysis system, and two AMTI force plates were used to track and analyze the participants' gait patterns, knee flexion angles, knee moment normalized by body weight, and swing time. For stair descent, no significant differences were found between prostheses. For stair ascent, Genium use resulted in: increased ability to use a step-over-step gait pattern (p=0.03), increased prosthetic side peak knee flexion (p<0.01), and increased swing duration (p<0.01). Changes in contralateral side outcomes and in knee moment were not significant. Overall the Genium knee decreased deficiency in gait patterns for stair ascent relative to the C-Leg, by enabling gait patterns that more closely resembled non-amputees. Copyright © 2017 Elsevier B.V. All rights reserved.

Terminal Schwann Cells Participate in Neuromuscular Synapse Remodeling during Reinnervation following Nerve Injury

PubMed Central

Kang, Hyuno; Tian, Le; Mikesh, Michelle; Lichtman, Jeff W.

2014-01-01

Schwann cells (SCs) at neuromuscular junctions (NMJs) play active roles in synaptic homeostasis and repair. We have studied how SCs contribute to reinnervation of NMJs using vital imaging of mice whose motor axons and SCs are transgenically labeled with different colors of fluorescent proteins. Motor axons most commonly regenerate to the original synaptic site by following SC-filled endoneurial tubes. During the period of denervation, SCs at the NMJ extend elaborate processes from the junction, as shown previously, but they also retract some processes from territory they previously occupied within the endplate. The degree of this retraction depends on the length of the period of denervation. We show that the topology of the remaining SC processes influences the branching pattern of regenerating axon terminals and the redistribution of acetylcholine receptors (AChRs). Upon arriving at the junction, regenerating axons follow existing SC processes within the old synaptic site. Some of the AChR loss that follows denervation is correlated with failure of portions of the old synaptic site that lack SC coverage to be reinnervated. New AChR clustering is also induced by axon terminals that follow SC processes extended during denervation. These observations show that SCs participate actively in the remodeling of neuromuscular synapses following nerve injury by their guidance of axonal reinnervation. PMID:24790203

Sprint Start Kinetics of Amputee and Non-Amputee Sprinters

PubMed Central

Willwacher, Steffen; Herrmann, Volker; Heinrich, Kai; Funken, Johannes; Strutzenberger, Gerda; Goldmann, Jan-Peter; Braunstein, Björn; Brazil, Adam; Irwin, Gareth; Potthast, Wolfgang; Brüggemann, Gert-Peter

2016-01-01

The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58–14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70–12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (−33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (−17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs. PMID:27846241

Sprint Start Kinetics of Amputee and Non-Amputee Sprinters.

PubMed

Willwacher, Steffen; Herrmann, Volker; Heinrich, Kai; Funken, Johannes; Strutzenberger, Gerda; Goldmann, Jan-Peter; Braunstein, Björn; Brazil, Adam; Irwin, Gareth; Potthast, Wolfgang; Brüggemann, Gert-Peter

2016-01-01

The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58-14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70-12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (-33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (-17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs.

Physiologic and biochemical aspects of skeletal muscle denervation and reinnervation

NASA Technical Reports Server (NTRS)

Max, S. R.; Mayer, R. F.

1984-01-01

Some of the physiologic and biochemical changes that occur in mammalian skeletal muscle following denervation and reinnervation are considered and some comparisons are made with changes observed following altered motor function. The nature of the trophic influence by which nerves control muscle properties are discussed, including the effects of choline acetyltransferase and acetylcholinesterase and the role of the acetylcholine receptor.

Patellofemoral arthroplasty in a bilateral Syme's amputee.

PubMed

Kanna, Raj; Barrett, David S

2016-01-01

We present the case of a 50-year-old woman, who is a bilateral Syme's amputee and subsequently underwent patellofemoral arthroplasty (PFA) for osteoarthritis primarily involving the patellofemoral (PF) joint. History and physical examination were suggestive of severe PF arthritis without patellar instability of the right knee. The diagnosis was confirmed by roentgenogram and a PFA was performed. A slightly modified rehabilitation program was implemented and the patient was followed until 6 years after surgery. In comparison to the preoperative scores, the Oxford, the Western Ontario and McMaster Universities (WOMAC), the Knee Society, and the Hospital for Special Surgery Knee Scores improved significantly (p < 0.05) at the time of final follow-up. PF problems specific to below-knee amputees, factors to be considered before performing PFA, and the drawbacks of other treatment modalities in these patients have been discussed.

Phantom somatosensory evoked potentials following selective intraneural electrical stimulation in two amputees.

PubMed

Granata, Giuseppe; Di Iorio, Riccardo; Romanello, Roberto; Iodice, Francesco; Raspopovic, Stanisa; Petrini, Francesco; Strauss, Ivo; Valle, Giacomo; Stieglitz, Thomas; Čvančara, Paul; Andreu, David; Divoux, Jean-Louis; Guiraud, David; Wauters, Loic; Hiairrassary, Arthur; Jensen, Winnie; Micera, Silvestro; Rossini, Paolo Maria

2018-06-01

The aim of the paper is to objectively demonstrate that amputees implanted with intraneural interfaces are truly able to feel a sensation in the phantom hand by recording "phantom" somatosensory evoked potentials from the corresponding brain areas. We implanted four transverse intrafascicular multichannel electrodes, available with percutaneous connections to a multichannel electrical stimulator, in the median and ulnar nerves of two left trans-radial amputees. Two channels of the implants that were able to elicit sensations during intraneural nerve stimulation were chosen, in both patients, for recording somatosensory evoked potentials. We recorded reproducible evoked responses by stimulating the median and the ulnar nerves in both cases. Latencies were in accordance with the arrival of somatosensory information to the primary somatosensory cortex. Our results provide evidence that sensations generated by intraneural stimulation are truly perceived by amputees and located in the phantom hand. Moreover, our results strongly suggest that sensations perceived in different parts of the phantom hand result in different evoked responses. Somatosensory evoked potentials obtained by selective intraneural electrical stimulation in amputee patients are a useful tool to provide an objective demonstration of somatosensory feedback in new generation bidirectional prostheses. Copyright © 2018. Published by Elsevier B.V.

Evaluation of disabilities and activities of daily living of war-related bilateral lower extremity amputees.

PubMed

Ebrahimzadeh, Mohammad H; Moradi, Ali; Bozorgnia, Shahram; Hallaj-Moghaddam, Mohammad

2016-02-01

Long-term consequences and the activities of daily living of bilateral lower limb amputation are not well documented. The aims of our study were to identify the long-term effects of bilateral lower extremity amputations on daily activities and understand how these amputees cope with their mobility assistive devices. Cross-sectional study. A total of 291 veterans with war bilateral lower limb amputations accepted to participate in a cross-sectional study. The average of follow-up was 25.4 years. A total of 152 amputees (54%) were involved in sports averagely 6.7 h per week. Bilateral amputees walk 10 m by the average of 15 ± 33 s, and they could walk continuously with their prosthesis 315 ± 295 m. They wore their prosthesis 6.8 ± 1.7 days per week and 7.9 ± 8.1 h per day. Of these, 6.7% of bilateral lower limb amputees needed help to wear their prosthesis; 88.3% of amputees used assistant device for walking. According to this survey, 73 (42%) prostheses in right limb were appropriate, 95 (54.6%) needed to be replaced, and 6 (3.4) needed to be fixed. On the left side, it was 76 (42%), 92 (52.0%), and 9 (5.1%), respectively. A total of 203 (74.9%) amputees reported limitations in at least one domain of the activities of daily living. The most common single item that affected the patients was ascending and descending stairs by the score of 66% of normal population. Veterans with bilateral lower limb amputations suffering from vast categories of daily problems. This study and its results confirm that bilateral lower limb amputees have major progressive disabilities in daily activities and their social performance. This should attract the attention of amputees' administrative organizations, social workers, health-care providers and caregiver providers. © The International Society for Prosthetics and Orthotics 2014.

Integration of surface electromyographic sensors with the transfemoral amputee socket: a comparison of four differing configurations.

PubMed

Hefferman, Gerald M; Zhang, Fan; Nunnery, Michael J; Huang, He

2015-04-01

In recent years, there has been an increased interest in recording high-quality electromyographic signals from within the sockets of lower-limb amputees. However, successful recording presents major challenges to both researchers and clinicians. This article details and compares four prototypical integrated socket-sensor designs used to record electromyographic signals from within the sockets of transfemoral amputees. Four prototypical socket-sensor configurations were constructed and tested on a single transfemoral amputee asked to perform sitting/standing, stair ascent/descent, and level ground walking. The number of large-amplitude motion artifacts generated using each prototype was quantified, the amount of skin irritation documented, and the comfort level of each assembly subjectively assessed by the amputee subject. Of the four configurations tested, the combination of a suction socket with integrated wireless surface electrodes generated the lowest number of large-amplitude motion artifacts, the least visible skin irritation, and was judged to be most comfortable by the amputee subject. The collection of high-quality electromyographic signals from an amputee's residual limb while maximizing patient comfort holds substantial potential to enhance neuromuscular clinical assessment and as a method of intuitive control of powered lower-limb prostheses. © The International Society for Prosthetics and Orthotics 2014.

A biomechanical analysis of the long-jump technique of elite female amputee athletes.

PubMed

Nolan, Lee; Patritti, Benjamin L; Simpson, Kathy J

2006-10-01

The purpose of this study was to investigate whether female lower-limb amputees conform to the established long-jump model and to compare the kinematics of the approach and take-off phases for elite female transfemoral and transtibial amputee long jumpers. Eight female transfemoral and nine female transtibial amputee athletes were videotaped (sagittal plane movements at 50 Hz) from third-to-last step to take-off during the 2004 Paralympic Games long-jump finals. After digitizing and reconstruction of 2D coordinates, key variables were calculated at each stride and during contact with the take-off board. Additionally, approach speed during the run-up of each jump was recorded (100 Hz) using a laser Doppler device (LDM 300 C Sport, Jenoptik Laser, Jena, Germany). The transfemoral amputees had a consistently higher center of mass height on the last three steps before take-off than the transtibial amputees. However, at touch-down onto the take-off board, they lowered their center of mass excessively so that from touch-down to take-off, they were actually lower than the transtibial amputees. This resulted in a greater negative vertical velocity at touch-down and may have inversely affected their jump performance. Female transtibial athletes conformed to the long-jump model, although adaptations to this technique were displayed. Female transfemoral athletes, however, exhibited no relationship between take-off speed and distance jumped, which may be attributable to their excessive lowering of their center-of-mass height at touch-down onto the take-off board. It is recommended that coaches and athletes proceed with caution when trying to replicate techniques used by able-bodied athletes because adaptations to the constraints of a prosthesis should be considered.

Return to Duty Rate of Amputee Soldiers in the Current Conflicts in Afghanistan and Iraq

DTIC Science & Technology

2010-06-01

Conclusion: During the 1980s , 11 of 469 amputees returned to active duty (2.3%). The number of amputees returning to duty has increased signifi- cantly...between 1980 and 1988, but only 11 of the 469 (2.3%) remained on active duty. The purpose of this study was to evaluate the return to duty rate of...During the 1980s and 1990s, no such designated military amputee centers were in operation. This may be one reason for the lower return to duty rate of

Patellofemoral arthroplasty in a bilateral Syme's amputee

PubMed Central

Kanna, Raj; Barrett, David S.

2016-01-01

We present the case of a 50-year-old woman, who is a bilateral Syme's amputee and subsequently underwent patellofemoral arthroplasty (PFA) for osteoarthritis primarily involving the patellofemoral (PF) joint. History and physical examination were suggestive of severe PF arthritis without patellar instability of the right knee. The diagnosis was confirmed by roentgenogram and a PFA was performed. A slightly modified rehabilitation program was implemented and the patient was followed until 6 years after surgery. In comparison to the preoperative scores, the Oxford, the Western Ontario and McMaster Universities (WOMAC), the Knee Society, and the Hospital for Special Surgery Knee Scores improved significantly (p < 0.05) at the time of final follow-up. PF problems specific to below-knee amputees, factors to be considered before performing PFA, and the drawbacks of other treatment modalities in these patients have been discussed. PMID:26908975

Joint Loads and Cartilage Stress in Intact Joints of Military Transtibial Amputees: Enhancing Quality of Life

DTIC Science & Technology

2017-04-01

crosstalk); analysis of tested subjects underway. 4) Developed analytical methods to obtain knee joint loads using EMG-driven inverse dynamics; analysis of...13/2018. Completion %: 40. Task 1.3: EMG-driven inverse dynamic (ID) analyses with OpenSim for amputee and control group subjects. Target date: 1...predicted by EMG-driven inverse dynamics. Two-three conference papers are being prepared for submission in February 2017. Other achievements. None

Immunohistologic analysis of spontaneous recurrent laryngeal nerve reinnervation in a rat model.

PubMed

Rosko, Andrew J; Kupfer, Robbi A; Oh, Sang S; Haring, Catherine T; Feldman, Eva L; Hogikyan, Norman D

2018-03-01

After recurrent laryngeal nerve injury (RLN), spontaneous reinnervation of the larynx occurs with input from multiple sources. The purpose of this study was to determine the timing and efficiency of reinnervation across a resected RLN segment in a rat model of RLN injury. Animal study. Twelve male 60-day-old Sprague Dawley rats underwent resection of a 5-mm segment of the right RLN. Rats were sacrificed at 1, 2, 4, and 12 weeks after nerve injury to harvest the larynx and trachea for immunohistologic analysis. The distal RLN segment was stained with neurofilament, and axons were counted and compared to the nonoperated side. Thyroarytenoid (TA) muscles were stained with alpha-bungarotoxin, synaptophysin, and neurofilament to identify intact neuromuscular junctions (NMJ). The number of intact NMJs from the denervated side was compared to the nonoperated side. Nerve fibers regenerated across the resected RLN gap into the distal recurrent laryngeal nerve to innervate the TA muscle. The number of nerve fibers in the distal nerve segment increased over time and reached the normal number by 12 weeks postdenervation. Axons formed intact neuromuscular junctions in the TA, with 48.8% ± 16.7% of the normal number of intact NMJs at 4 weeks and 88.3% ± 30.1% of the normal number by 12 weeks. Following resection of an RLN segment in a rat model, nerve fibers spontaneously regenerate through the distal segment of the transected nerve and form intact NMJs in order to reinnervate the TA muscle. NA. Laryngoscope, 128:E117-E122, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Mechanisms of Gait Asymmetry Due to Push-off Deficiency in Unilateral Amputees

PubMed Central

Adamczyk, Peter Gabriel; Kuo, Arthur D.

2015-01-01

Unilateral lower-limb amputees exhibit asymmetry in many gait features, such as ground force, step time, step length, and joint mechanics. Although these asymmetries result from weak prosthetic-side push-off, there is no proven mechanistic explanation of how that impairment propagates to the rest of the body. We used a simple dynamic walking model to explore possible consequences of a unilateral impairment similar to that of a transtibial amputee. The model compensates for reduced push-off work from one leg by performing more work elsewhere, for example during the middle of stance by either or both legs. The model predicts several gait abnormalities, including slower forward velocity of the body center-of-mass (COM) during intact-side stance, greater energy dissipation in the intact side, and more positive work overall. We tested these predictions with data from unilateral transtibial amputees (N = 11) and non-amputee control subjects (N = 10) walking on an instrumented treadmill. We observed several predicted asymmetries, including forward velocity during stance phases and energy dissipation from the two limbs, as well as greater work overall. Secondary adaptations, such as to reduce discomfort, may exacerbate asymmetry, but these simple principles suggest that some asymmetry may be unavoidable in cases of unilateral limb loss. PMID:25222950

Amputee skin condition: occlusion, stratum corneum hydration and free amino acid levels.

PubMed

Visscher, Marty O; Robinson, Marisa; Fugit, Benetta; Rosenberg, Richard J; Hoath, Steven B; Randall Wickett, R

2011-03-01

Patients with a prosthetic limb report negative skin effects, including irritation, rash and chafing, which can lead to infection, discomfort and reduced wear time to significantly impact normal activities. The aims were to examine the epidermal integrity (transepidermal water loss, TEWL), stratum corneum (SC) hydration [moisture accumulation rate (MAT)], friction and biomechanical properties in active below the knee amputees and to determine the effects of an inert sock liner on skin condition. The liner reduced hydration, TEWL and friction and increased elasticity versus the amputee's conventional skin care methods. Residual limb TEWL was increased and MAT was reduced versus the contralateral normal skin. In a second study, we hypothesized that complete occlusion would decrease free amino acids (FAA) and quantified them by high performance liquid chromatography in an adult volar forearm model. Occlusion with a water vapor impermeable wet dressing led to increased TEWL, erythema and dryness and reduced MAT versus normal skin, comparable to the results in the amputees. The FAA levels were significantly reduced for the occluded sites. The results suggest that residual limb occlusion in amputees may block the formation of FAA in the upper SC. Therapies based on replacement of water binding FAAs, may alleviate the consequences of long-term occlusion.

Sympathetic sprouting drives hippocampal cholinergic reinnervation that prevents loss of a muscarinic receptor-dependent long-term depression at CA3-CA1 synapses.

PubMed

Scheiderer, Cary L; McCutchen, Eve; Thacker, Erin E; Kolasa, Krystyna; Ward, Matthew K; Parsons, Dee; Harrell, Lindy E; Dobrunz, Lynn E; McMahon, Lori L

2006-04-05

Degeneration of septohippocampal cholinergic neurons results in memory deficits attributable to loss of cholinergic modulation of hippocampal synaptic circuits. A remarkable consequence of cholinergic degeneration is the sprouting of noradrenergic sympathetic fibers from the superior cervical ganglia into hippocampus. The functional impact of sympathetic ingrowth on synaptic physiology has never been investigated. Here, we report that, at CA3-CA1 synapses, a Hebbian form of long-term depression (LTD) induced by muscarinic M1 receptor activation (mLTD) is lost after medial septal lesion. Unexpectedly, expression of mLTD is rescued by sympathetic sprouting. These effects are specific because LTP and other forms of LTD are unaffected. The rescue of mLTD expression is coupled temporally with the reappearance of cholinergic fibers in hippocampus, as assessed by the immunostaining of fibers for VAChT (vesicular acetylcholine transporter). Both the cholinergic reinnervation and mLTD rescue are prevented by bilateral superior cervical ganglionectomy, which also prevents the noradrenergic sympathetic sprouting. The new cholinergic fibers likely originate from the superior cervical ganglia because unilateral ganglionectomy, performed when cholinergic reinnervation is well established, removes the reinnervation on the ipsilateral side. Thus, the temporal coupling of the cholinergic reinnervation with mLTD rescue, together with the absence of reinnervation and mLTD expression after ganglionectomy, demonstrate that the autonomic-driven cholinergic reinnervation is essential for maintaining mLTD after central cholinergic cell death. We have discovered a novel phenomenon whereby the autonomic and central nervous systems experience structural rearrangement to replace lost cholinergic innervation in hippocampus, with the consequence of preserving a form of LTD that would otherwise be lost as a result of cholinergic degeneration.

Swarm-wavelet based extreme learning machine for finger movement classification on transradial amputees.

PubMed

Anam, Khairul; Al-Jumaily, Adel

2014-01-01

The use of a small number of surface electromyography (EMG) channels on the transradial amputee in a myoelectric controller is a big challenge. This paper proposes a pattern recognition system using an extreme learning machine (ELM) optimized by particle swarm optimization (PSO). PSO is mutated by wavelet function to avoid trapped in a local minima. The proposed system is used to classify eleven imagined finger motions on five amputees by using only two EMG channels. The optimal performance of wavelet-PSO was compared to a grid-search method and standard PSO. The experimental results show that the proposed system is the most accurate classifier among other tested classifiers. It could classify 11 finger motions with the average accuracy of about 94 % across five amputees.

Bioengineered nerve regeneration and muscle reinnervation

PubMed Central

Kingham, Paul J; Terenghi, Giorgio

2006-01-01

The peripheral nervous system has the intrinsic capacity to regenerate but the reinnervation of muscles is often suboptimal and results in limited recovery of function. Injuries to nerves that innervate complex organs such as the larynx are particularly difficult to treat. The many functions of the larynx have evolved through the intricate neural regulation of highly specialized laryngeal muscles. In this review, we examine the responses of nerves and muscles to injury, focusing on changes in the expression of neurotrophic factors, and highlight differences between the skeletal limb and laryngeal muscle systems. We also describe how artificial nerve conduits have become a useful tool for delivery of neurotrophic factors as therapeutic agents to promote peripheral nerve repair and might eventually be useful in the treatment of laryngeal nerve injury. PMID:17005023

The Capability of Fiber Bragg Grating Sensors to Measure Amputees' Trans-Tibial Stump/Socket Interface Pressures

PubMed Central

Al-Fakih, Ebrahim A.; Abu Osman, Noor Azuan; Eshraghi, Arezoo; Adikan, Faisal Rafiq Mahamd

2013-01-01

This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ∼0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction. PMID:23941909

The capability of fiber Bragg grating sensors to measure amputees' trans-tibial stump/socket interface pressures.

PubMed

Al-Fakih, Ebrahim A; Osman, Noor Azuan Abu; Eshraghi, Arezoo; Adikan, Faisal Rafiq Mahamd

2013-08-12

This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ~0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction.

Selective reinnervation: a comparison of recovery following microsuture and conduit nerve repair.

PubMed

Evans, P J; Bain, J R; Mackinnon, S E; Makino, A P; Hunter, D A

1991-09-20

Selective reinnervation was studied by comparing the regeneration across a conventional neurorraphy versus a conduit nerve repair. Lewis rats underwent right sciatic nerve transection followed by one of four different nerve repairs (n = 8/group). In groups I and II a conventional neurorraphy was performed and in groups III and IV the proximal and distal stumps were coapted by use of a silicone conduit with an interstump gap of 5 mm. The proximal and distal stumps in groups I and III were aligned anatomically correct and the proximal stump was rotated 180 degrees in groups II and IV (i.e. proximal peroneal nerve opposite the distal tibial nerve and the proximal tibial nerve opposite the distal peroneal nerve). By 14 weeks, there was an equivalent, but incomplete return in sciatic function index (SFI) in groups I, III, and IV as measured by walking track analysis. However, the SFI became unmeasurable by 6 weeks in all group II animals. At 14 weeks, the percent innervation of the tibialis anterior and medial gastronemius muscles by the peroneal and tibial nerves respectively was estimated by selective compound muscle action potential amplitude recordings. When fascicular alignment was reversed, there was greater tibial (P = 0.02) and lesser peroneal (P = 0.005) innervation of the gastrocnemius muscle in the conduit (group IV) versus the neurorraphy (group II) group. This suggests that the gastrocnemius muscle may be selectively reinnervated by the tibial nerve. However, there was no evidence of selective reinnervation of the tibialis anterior muscle. Despite these differences, the functional recovery in both conduit repair groups (III and IV) was equivalent to a correctly aligned microsuture repair (group I) and superior to that in the incorrectly aligned microsuture repair (group II).

Is fast fiber innervation responsible for increased acetylcholinesterase activity in reinnervating soleus muscles?

NASA Technical Reports Server (NTRS)

Misulis, K. E.; Dettbarn, W. D.

1985-01-01

An investigation was conducted as to whether the predominantly slow SOL, which is low in AChE activity, is initially reinnervated by axons that originally innervated fast muscle fibers with high AChE activity, such as those of the EDL. Local denervation of the SOL in the guinea pig was performed because this muscle is composed solely of slow (type I) fibers; thereby virtually eliminating the possibility of homologous muscle fast fiber innervation. The overshoot in this preparation was qualitatively similar to that seen with distal denervation in the guinea pig and local and distal denervation in the rat. Thus, initial fast fiber innvervation is not responsible for the patterns of change in AChE activity seen with reinnervation in the SOL. It is concluded that the neural control of AChe is different in these two muscles and may reflect specific differences in the characteristics of AChE regulation in fast and slow muscle.

Effect of denervation and reinnervation on oxidation of 6-(C-14) glucose by rat skeletal muscle homogenates

NASA Technical Reports Server (NTRS)

Dubois, D. C.; Max, S. R.

1983-01-01

The effects of denervation and reinnervation of the rat extensor digitorum longus muscle on the oxidation of 6-(C-14) glucose to (C-14)O2 is investigated. Results show that the rate of (C-14)O2 production decreased dramatically following denervation and the decrease became significant 20 days after nerve section. The changes which occurred prior to day 20 apparently reflected the decline of muscle mass. The decreased (C-14)O2 production was found to be due to reduced capacity of the enzymatic system, while there was no change in the apparent affinity for glucose. Results of mixing experiments showed that the loss of oxidative capacity following denervation is not caused by the production of soluble inhibitors by degenerating muscle. Measurements of the (C-14)O2 revealed that oxidative metabolism recovered during reinnervation. The specific activity in reinnervated muscles displayed an 'overshoot' of approximately 50 percent, which returned to control levels by day 60. The time-course of the denervation-mediated change indicates that altered oxidative capacity is secondary to events that initiate dennervation changes in muscle, although diminished oxidative capacity may be of considerable metabolic significance in denervated muscle.

A comparison of the real-time controllability of pattern recognition to conventional myoelectric control for discrete and simultaneous movements

PubMed Central

2014-01-01

Myoelectric control has been used for decades to control powered upper limb prostheses. Conventional, amplitude-based control has been employed to control a single prosthesis degree of freedom (DOF) such as closing and opening of the hand. Within the last decade, new and advanced arm and hand prostheses have been constructed that are capable of actuating numerous DOFs. Pattern recognition control has been proposed to control a greater number of DOFs than conventional control, but has traditionally been limited to sequentially controlling DOFs one at a time. However, able-bodied individuals use multiple DOFs simultaneously, and it may be beneficial to provide amputees the ability to perform simultaneous movements. In this study, four amputees who had undergone targeted motor reinnervation (TMR) surgery with previous training using myoelectric prostheses were configured to use three control strategies: 1) conventional amplitude-based myoelectric control, 2) sequential (one-DOF) pattern recognition control, 3) simultaneous pattern recognition control. Simultaneous pattern recognition was enabled by having amputees train each simultaneous movement as a separate motion class. For tasks that required control over just one DOF, sequential pattern recognition based control performed the best with the lowest average completion times, completion rates and length error. For tasks that required control over 2 DOFs, the simultaneous pattern recognition controller performed the best with the lowest average completion times, completion rates and length error compared to the other control strategies. In the two strategies in which users could employ simultaneous movements (conventional and simultaneous pattern recognition), amputees chose to use simultaneous movements 78% of the time with simultaneous pattern recognition and 64% of the time with conventional control for tasks that required two DOF motions to reach the target. These results suggest that when amputees are given the

Effect of duration of denervation on outcomes of ansa-recurrent laryngeal nerve reinnervation.

PubMed

Li, Meng; Chen, Shicai; Wang, Wei; Chen, Donghui; Zhu, Minhui; Liu, Fei; Zhang, Caiyun; Li, Yan; Zheng, Hongliang

2014-08-01

To investigate the efficacy of laryngeal reinnervation with ansa cervicalis among unilateral vocal fold paralysis (UVFP) patients with different denervation durations. We retrospectively reviewed 349 consecutive UVFP cases of delayed ansa cervicalis to the recurrent laryngeal nerve (RLN) anastomosis. Potential influencing factors were analyzed in multivariable logistic regression analysis. Stratification analysis performed was aimed at one of the identified significant variables: denervation duration. Videostroboscopy, perceptual evaluation, acoustic analysis, maximum phonation time (MPT), and laryngeal electromyography (EMG) were performed preoperatively and postoperatively. Gender, age, preoperative EMG status and denervation duration were analyzed in multivariable logistic regression analysis. Stratification analysis was performed on denervation duration, which was divided into three groups according to the interval between RLN injury and reinnervation: group A, 6 to 12 months; group B, 12 to 24 months; and group C, > 24 months. Age, preoperative EMG, and denervation duration were identified as significant variables in multivariable logistic regression analysis. Stratification analysis on denervation duration showed significant differences between group A and C and between group B and C (P < 0.05)-but showed no significant difference between group A and B (P > 0.05) with regard to parameters overall grade, jitter, shimmer, noise-to-harmonics ratio, MPT, and postoperative EMG. In addition, videostroboscopic and laryngeal EMG data, perceptual and acoustic parameters, and MPT values were significantly improved postoperatively in each denervation duration group (P < 0.01). Although delayed laryngeal reinnervation is proved valid for UVFP, surgical outcome is better if the procedure is performed within 2 years after nerve injury than that over 2 years. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Quadriceps muscle injury in trans-femoral amputees.

PubMed

Alsindi, Z; Datta, D

1998-12-01

Two male trans-femoral amputees using modular trans-femoral prostheses lost control and fell to the ground when their prosthetic knees gave way. The semi-automatic knee lock malfunctioned in the first case while the free knee stabilising mechanics gave way in the second case. This resulted in a high tensile force acting on the contralateral quadriceps muscle causing it to rupture. As there are a significant number of patients with both kinds of prostheses it is important to be aware of this possibility so that necessary actions can be taken to minimise its occurrence. Even with the currently available weight activated stance phase control, the prosthetic knee will give way if the knee is flexed more than 20 degrees on weight bearing. Good power and control of hip extensors on the amputation side is needed to control the prosthetic knee joint, especially in the early stage of the walking cycle, i.e., from heel strike to mid-stance. Quadriceps muscle injury in amputees, as far as the authors are aware, has not been reported previously.

Long-term high-level exercise promotes muscle reinnervation with age.

PubMed

Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Fruhmann, Hannah; Vogelauer, Michael; Burggraf, Samantha; Mayr, Winfried; Krenn, Matthias; Paternostro-Sluga, Tatjana; Hamar, Dusan; Cvecka, Jan; Sedliak, Milan; Tirpakova, Veronika; Sarabon, Nejc; Musarò, Antonio; Sandri, Marco; Protasi, Feliciano; Nori, Alessandra; Pond, Amber; Zampieri, Sandra

2014-04-01

The histologic features of aging muscle suggest that denervation contributes to atrophy, that immobility accelerates the process, and that routine exercise may protect against loss of motor units and muscle tissue. Here, we compared muscle biopsies from sedentary and physically active seniors and found that seniors with a long history of high-level recreational activity up to the time of muscle biopsy had 1) lower loss of muscle strength versus young men (32% loss in physically active vs 51% loss in sedentary seniors); 2) fewer small angulated (denervated) myofibers; 3) a higher percentage of fiber-type groups (reinnervated muscle fibers) that were almost exclusive of the slow type; and 4) sparse normal-size muscle fibers coexpressing fast and slow myosin heavy chains, which is not compatible with exercise-driven muscle-type transformation. The biopsies from the old physically active seniors varied from sparse fiber-type groupings to almost fully transformed muscle, suggesting that coexpressing fibers appear to fill gaps. Altogether, the data show that long-term physical activity promotes reinnervation of muscle fibers and suggest that decades of high-level exercise allow the body to adapt to age-related denervation by saving otherwise lost muscle fibers through selective recruitment to slow motor units. These effects on size and structure of myofibers may delay functional decline in late aging.

Improved Training Method for Rapid Rehabilitation of Amputees

DTIC Science & Technology

2013-03-01

crowded environments, stairs , ramps, and hills. The key factor that limits the ability of amputees to achieve maximum functional capabilities is falls...Method for evoking a trip response using a treadmill based perturbation during locomotion”, has been submitted to the Journal of Biomechanics o

Progranulin promotes peripheral nerve regeneration and reinnervation: role of notch signaling.

PubMed

Altmann, Christine; Vasic, Verica; Hardt, Stefanie; Heidler, Juliana; Häussler, Annett; Wittig, Ilka; Schmidt, Mirko H H; Tegeder, Irmgard

2016-10-22

Peripheral nerve injury is a frequent cause of lasting motor deficits and chronic pain. Although peripheral nerves are capable of regrowth they often fail to re-innervate target tissues. Using newly generated transgenic mice with inducible neuronal progranulin overexpression we show that progranulin accelerates axonal regrowth, restoration of neuromuscular synapses and recovery of sensory and motor functions after injury of the sciatic nerve. Oppositely, progranulin deficient mice have long-lasting deficits in motor function tests after nerve injury due to enhanced losses of motor neurons and stronger microglia activation in the ventral horn of the spinal cord. Deep proteome and gene ontology (GO) enrichment analysis revealed that the proteins upregulated in progranulin overexpressing mice were involved in 'regulation of transcription' and 'response to insulin' (GO terms). Transcription factor prediction pointed to activation of Notch signaling and indeed, co-immunoprecipitation studies revealed that progranulin bound to the extracellular domain of Notch receptors, and this was functionally associated with higher expression of Notch target genes in the dorsal root ganglia of transgenic mice with neuronal progranulin overexpression. Functionally, these transgenic mice recovered normal gait and running, which was not achieved by controls and was stronger impaired in progranulin deficient mice. We infer that progranulin activates Notch signaling pathways, enhancing thereby the regenerative capacity of partially injured neurons, which leads to improved motor function recovery.

Skin problems of the stump in lower limb amputees: 1. A clinical study.

PubMed

Meulenbelt, Henk E J; Geertzen, Jan H B; Jonkman, Marcel F; Dijkstra, Pieter U

2011-03-01

Use of a prosthesis in lower limb amputees can lead to skin problems of the amputation stump. However, little is known about the epidemiology and type of problems experienced. We conducted a cross-sectional survey consisting of a questionnaire and a clinical assessment of the amputation stump. The aims of the study were to estimate the prevalence of skin problems of the amputation stump, to evaluate the impact of these skin problems and to evaluate differences between clinically observed skin problems and skin problems reported by the amputee. Participants (n = 124) were recruited from among lower limb amputees who visited an orthopaedic workshop. The prevalence of skin problems was 36%. Problems identified were: reduction in prosthesis use, and reduction in walking distance without a break. Significantly more skin problems were reported than observed (p = 0.011). Cold skin and excessive perspiration in particular were significantly more reported than observed.

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation

PubMed Central

Segal, Ava D.; Zelik, Karl E.; Klute, Glenn K.; Morgenroth, David C.; Hahn, Michael E.; Orendurff, Michael S.; Adamczyk, Peter G.; Collins, Steven H.; Kuo, Arthur D.; Czerniecki, Joseph M.

2015-01-01

The lack of functional ankle musculature in lower limb amputees contributes to the reduced prosthetic ankle push-off, compensations at other joints and more energetically costly gait commonly observed in comparison to non-amputees. A variety of energy storing and return prosthetic feet have been developed to address these issues but have not been shown to sufficiently improve amputee biomechanics and energetic cost, perhaps because the timing and magnitude of energy return is not controlled. The goal of this study was to examine how a prototype microprocessor-controlled prosthetic foot designed to store some of the energy during loading and return it during push-off affects amputee gait. Unilateral transtibial amputees wore the Controlled Energy Storage and Return prosthetic foot (CESR), a conventional foot (CONV), and their previously prescribed foot (PRES) in random order. Three-dimensional gait analysis and net oxygen consumption were collected as participants walked at constant speed. The CESR foot demonstrated increased energy storage during early stance, increased prosthetic foot peak push-off power and work, increased prosthetic limb center of mass (COM) push-off work and decreased intact limb COM collision work compared to CONV and PRES. The biological contribution of the positive COM work for CESR was reduced compared to CONV and PRES. However, the net metabolic cost for CESR did not change compared to CONV and increased compared to PRES, which may partially reflect the greater weight, lack of individualized size and stiffness and relatively less familiarity for CESR and CONV. Controlled energy storage and return enhanced prosthetic push-off, but requires further design modifications to improve amputee walking economy. PMID:22100728

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation.

PubMed

Segal, Ava D; Zelik, Karl E; Klute, Glenn K; Morgenroth, David C; Hahn, Michael E; Orendurff, Michael S; Adamczyk, Peter G; Collins, Steven H; Kuo, Arthur D; Czerniecki, Joseph M

2012-08-01

The lack of functional ankle musculature in lower limb amputees contributes to the reduced prosthetic ankle push-off, compensations at other joints and more energetically costly gait commonly observed in comparison to non-amputees. A variety of energy storing and return prosthetic feet have been developed to address these issues but have not been shown to sufficiently improve amputee biomechanics and energetic cost, perhaps because the timing and magnitude of energy return is not controlled. The goal of this study was to examine how a prototype microprocessor-controlled prosthetic foot designed to store some of the energy during loading and return it during push-off affects amputee gait. Unilateral transtibial amputees wore the Controlled Energy Storage and Return prosthetic foot (CESR), a conventional foot (CONV), and their previously prescribed foot (PRES) in random order. Three-dimensional gait analysis and net oxygen consumption were collected as participants walked at constant speed. The CESR foot demonstrated increased energy storage during early stance, increased prosthetic foot peak push-off power and work, increased prosthetic limb center of mass (COM) push-off work and decreased intact limb COM collision work compared to CONV and PRES. The biological contribution of the positive COM work for CESR was reduced compared to CONV and PRES. However, the net metabolic cost for CESR did not change compared to CONV and increased compared to PRES, which may partially reflect the greater weight, lack of individualized size and stiffness and relatively less familiarity for CESR and CONV. Controlled energy storage and return enhanced prosthetic push-off, but requires further design modifications to improve amputee walking economy. Published by Elsevier B.V.

Gait asymmetry of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.

PubMed

Kaufman, Kenton R; Frittoli, Serena; Frigo, Carlo A

2012-06-01

Amputees walk with an asymmetrical gait, which may lead to future musculoskeletal degenerative changes. The purpose of this study was to compare the gait asymmetry of active transfemoral amputees while using a passive mechanical knee joint or a microprocessor-controlled knee joint. Objective 3D gait measurements were obtained in 15 subjects (12 men and 3 women; age 42, range 26-57). Research participants were longtime users of a mechanical prosthesis (mean 20 years, range 3-36 years). Joint symmetry was calculated using a novel method that includes the entire waveform throughout the gait cycle. There was no significant difference in hip, knee and ankle kinematics symmetry when using the different knee prostheses. In contrast, the results demonstrated a significant improvement in lower extremity joint kinetics symmetry when using the microprocessor-controlled knee. Use of the microprocessor-controlled knee joint resulted in improved gait symmetry. These improvements may lead to a reduction in the degenerative musculoskeletal changes often experienced by amputees. Copyright © 2011 Elsevier Ltd. All rights reserved.

Magnetic resonance spectroscopy of current hand amputees reveals evidence for neuronal-level changes in former sensorimotor cortex

PubMed Central

Choi, In-Young; Lee, Phil; Peng, Huiling; Kaufman, Christina L.; Frey, Scott H.

2017-01-01

Deafferentation is accompanied by large-scale functional reorganization of maps in the primary sensory and motor areas of the hemisphere contralateral to injury. Animal models of deafferentation suggest a variety of cellular-level changes including depression of neuronal metabolism and even neuronal death. Whether similar neuronal changes contribute to patterns of reorganization within the contralateral sensorimotor cortex of chronic human amputees is uncertain. We used functional MRI-guided proton magnetic resonance spectroscopy to test the hypothesis that unilateral deafferentation is associated with lower levels of N-acetylaspartate (NAA, a putative marker of neuronal integrity) in the sensorimotor hand territory located contralateral to the missing hand in chronic amputees (n = 19) compared with the analogous hand territory of age- and sex-matched healthy controls (n = 28). We also tested whether former amputees [i.e., recipients of replanted (n = 3) or transplanted (n = 2) hands] exhibit NAA levels that are indistinguishable from controls, possible evidence for reversal of the effects of deafferentation. As predicted, relative to controls, current amputees exhibited lower levels of NAA that were negatively and significantly correlated with the time after amputation. Contrary to our prediction, NAA levels in both replanted and transplanted patients fell within the range of the current amputees. We suggest that lower levels of NAA in current amputees reflects altered neuronal integrity consequent to chronic deafferentation. Thus local changes in NAA levels may provide a means of assessing neuroplastic changes in deafferented cortex. Results from former amputees suggest that these changes may not be readily reversible through reafferentation. NEW & NOTEWORTHY This study is the first to use functional magnetic resonance-guided magnetic resonance spectroscopy to examine neurochemical mechanisms underlying functional reorganization in the primary somatosensory and

Parasympathetic reinnervation accompanied by improved post-exercise heart rate recovery and quality of life in heart transplant recipients.

PubMed

Imamura, Teruhiko; Kinugawa, Koichiro; Okada, Ikuko; Kato, Naoko; Fujino, Takeo; Inaba, Toshiro; Maki, Hisataka; Hatano, Masaru; Kinoshita, Osamu; Nawata, Kan; Kyo, Shunei; Ono, Minoru

2015-01-01

Although sympathetic reinnervation is accompanied by the improvement of exercise tolerability during the first years after heart transplantation (HTx), little is known about parasympathetic reinnervation and its clinical impact. We enrolled 21 recipients (40 ± 16 years, 71% male) who had received successive cardiopulmonary exercise testing at 6 months, and 1 and 2 years after HTx. Exercise parameters such as peak oxygen consumption or achieved maximum load remained unchanged, whereas recovery parameters including heart rate (HR) recovery during 2 minutes and the delay of peak HR, which are influenced by parasympathetic activity, improved significantly during post-HTx 2 years (P < 0.05 for both). HR variability was analysed at post-HTx 6 months in 18 recipients, and high frequency power, representing parasympathetic activity, was significantly associated with the 2 recovery parameters (P < 0.05 for all). We also assessed quality of life using the Minnesota Living with Heart Failure (HF) Questionnaire at post-HTx 6 months and 2 years in the same 18 recipients, and those with improved recovery parameters enjoyed a better HF-specific quality of life (P < 0.05 for both). In conclusion, parasympathetic reinnervation emerges along with improved post-exercise recovery ability of HR and quality of life during post-HTx 2 years.

Online myoelectric control of a dexterous hand prosthesis by transradial amputees.

PubMed

Cipriani, Christian; Antfolk, Christian; Controzzi, Marco; Lundborg, Göran; Rosen, Birgitta; Carrozza, Maria Chiara; Sebelius, Fredrik

2011-06-01

A real-time pattern recognition algorithm based on k-nearest neighbors and lazy learning was used to classify, voluntary electromyography (EMG) signals and to simultaneously control movements of a dexterous artificial hand. EMG signals were superficially recorded by eight pairs of electrodes from the stumps of five transradial amputees and forearms of five able-bodied participants and used online to control a robot hand. Seven finger movements (not involving the wrist) were investigated in this study. The first objective was to understand whether and to which extent it is possible to control continuously and in real-time, the finger postures of a prosthetic hand, using superficial EMG, and a practical classifier, also taking advantage of the direct visual feedback of the moving hand. The second objective was to calculate statistical differences in the performance between participants and groups, thereby assessing the general applicability of the proposed method. The average accuracy of the classifier was 79% for amputees and 89% for able-bodied participants. Statistical analysis of the data revealed a difference in control accuracy based on the aetiology of amputation, type of prostheses regularly used and also between able-bodied participants and amputees. These results are encouraging for the development of noninvasive EMG interfaces for the control of dexterous prostheses.

Physical activity and quality of life of amputees in southern Brazil.

PubMed

da Silva, Rudney; Rizzo, Julia Ghazel; Gutierres Filho, Paulo José Barbosa; Ramos, Valmor; Deans, Sarah

2011-12-01

Physical activity is a positive component of human health. Its effects are associated with improvement in physical, psychological and social aspects of quality of life. Physical activity is therefore an important factor in the rehabilitation of amputees. To analyse the relationship between physical activity and quality of life for amputees in southern Brazil. Descriptive, cross-sectional design with nonrandomized sample. A total of 40 questionnaire instruments were distributed to subjects who met the inclusion criteria, with a response rate of 55% (22 individuals, n = 15 males, n = 7 females). Outcome measurements were obtained through the International Physical Activity Questionnaire and World Health Organization Quality of Life-Bref. The sample was characterized by physically active adult male prosthetic users with positive quality of life, and amputation below the right knee caused by mechanical trauma related to traffic accidents with motorcycles. Significant correlations were identified between all domains of quality of life and between level of physical activity and psychological quality of life. No correlation was identified between gender and quality of life variables or physical activity levels. This study showed that in very active amputees of both genders, level of physical activity is not associated with quality of life except for the psychological domain.

A Powered Prosthetic Intervention for Bilateral Transfemoral Amputees

PubMed Central

Lawson, Brian E.; Ruhe, Brian; Shultz, Amanda; Goldfarb, Michael

2014-01-01

This paper presents the design and validation of a control system for a pair of powered knee and ankle prostheses to be used as a prosthetic intervention for bilateral transfemoral amputees. The control system leverages communication between the prostheses for enhanced awareness and stability, along with power generation at the knee and ankle joints to better restore biomechanical functionality in level ground walking. The control methodology employed is a combination of an impedance-based framework for weight-bearing portions of gait and a trajectory-based approach for the non-weight-bearing portions. The control system was implemented on a pair of self-contained powered knee and ankle prostheses, and the ability of the prostheses and control approach to provide walking functionality was assessed in a set of experimental trials with a bilateral transfemoral amputee subject. Specifically, experimental data from these trials indicate that the powered prostheses and bilateral control architecture provide gait kinematics that reproduce healthy gait kinematics to a greater extent than the subject’s daily-use passive prostheses. PMID:25014950

Ansa-RLN reinnervation for unilateral vocal fold paralysis in adolescents and young adults.

PubMed

Smith, Marshall E; Roy, Nelson; Stoddard, Kelly

2008-09-01

To assess the outcomes of management of unilateral vocal fold paralysis by ansa-RLN reinnervation in a series of patients ages 12-21. Clinical outcomes study. Six consecutive adolescents and young adults (ages 12-21 years) seeking treatment for unilateral vocal fold paralysis and glottal incompetence underwent ansa-RLN neurorraphy. Pre- and post-operative voice recordings acquired at least 1 year following surgery were submitted to acoustic and perceptual analysis. Patient-based measures were also taken. Mean perceptual visual analogue scale rating of dysphonia severity (0mm=profoundly abnormal voice, 100mm=completely normal voice) improved from 50mm pre-operatively to 82mm post-operatively. Mean maximum phonation time improved from 6.5s to 13.2s. Pitch and dynamic range were also observed to improve. Global self-ratings of voice function (0-100%) increased from 31.2% to 81.6% of normal. Ansa-RLN reinnervation is an effective treatment option for adolescents and young adults with unilateral vocal fold paralysis. The procedure has the potential to improve vocal function substantially, especially in those with isolated paralysis of the recurrent laryngeal nerve. The procedure alleviates the disadvantages associated with other surgical options for this age group.

Crowd-Sourced Amputee Gait Data: A Feasibility Study Using YouTube Videos of Unilateral Trans-Femoral Gait.

PubMed

Gardiner, James; Gunarathne, Nuwan; Howard, David; Kenney, Laurence

2016-01-01

Collecting large datasets of amputee gait data is notoriously difficult. Additionally, collecting data on less prevalent amputations or on gait activities other than level walking and running on hard surfaces is rarely attempted. However, with the wealth of user-generated content on the Internet, the scope for collecting amputee gait data from alternative sources other than traditional gait labs is intriguing. Here we investigate the potential of YouTube videos to provide gait data on amputee walking. We use an example dataset of trans-femoral amputees level walking at self-selected speeds to collect temporal gait parameters and calculate gait asymmetry. We compare our YouTube data with typical literature values, and show that our methodology produces results that are highly comparable to data collected in a traditional manner. The similarity between the results of our novel methodology and literature values lends confidence to our technique. Nevertheless, clear challenges with the collection and interpretation of crowd-sourced gait data remain, including long term access to datasets, and a lack of validity and reliability studies in this area.

Crowd-Sourced Amputee Gait Data: A Feasibility Study Using YouTube Videos of Unilateral Trans-Femoral Gait

PubMed Central

Gardiner, James; Gunarathne, Nuwan; Howard, David; Kenney, Laurence

2016-01-01

Collecting large datasets of amputee gait data is notoriously difficult. Additionally, collecting data on less prevalent amputations or on gait activities other than level walking and running on hard surfaces is rarely attempted. However, with the wealth of user-generated content on the Internet, the scope for collecting amputee gait data from alternative sources other than traditional gait labs is intriguing. Here we investigate the potential of YouTube videos to provide gait data on amputee walking. We use an example dataset of trans-femoral amputees level walking at self-selected speeds to collect temporal gait parameters and calculate gait asymmetry. We compare our YouTube data with typical literature values, and show that our methodology produces results that are highly comparable to data collected in a traditional manner. The similarity between the results of our novel methodology and literature values lends confidence to our technique. Nevertheless, clear challenges with the collection and interpretation of crowd-sourced gait data remain, including long term access to datasets, and a lack of validity and reliability studies in this area. PMID:27764226

Effects of Lumbar Strengthening Exercise in Lower-Limb Amputees With Chronic Low Back Pain.

PubMed

Shin, Min Kyung; Yang, Hee Seung; Yang, Hea-Eun; Kim, Dae Hyun; Ahn, Bo Ram; Kwon, Hyup; Lee, Ju Hwan; Jung, Suk; Choi, Hyun Chul; Yun, Sun Keaung; Ahn, Dong Young; Sim, Woo Sob

2018-02-01

To analyze the effect of lumbar strengthening exercise in lower-limb amputees with chronic low back pain. We included in this prospective study 19 lower-limb amputees who had experienced low back pain for longer than 6 months. Participants were treated with 30-minute lumbar strengthening exercises, twice weekly, for 8 weeks. We used the visual analog scale (VAS), and Oswestry low back pain disability questionnaire, and measured parameters such as iliopsoas length, abdominal muscle strength, back extensor strength, and back extensor endurance. In addition, we assessed the isometric peak torque and total work of the trunk flexors and extensors using isokinetic dynamometer. The pre- and post-exercise measurements were compared. Compared with the baseline, abdominal muscle strength (from 4.4±0.7 to 4.8±0.6), back extensor strength (from 2.6±0.6 to 3.5±1.2), and back extensor endurance (from 22.3±10.7 to 46.8±35.1) improved significantly after 8 weeks. The VAS decreased significantly from 4.6±2.2 to 2.6±1.6 after treatment. Furthermore, the peak torque and total work of the trunk flexors and extensors increased significantly (p<0.05). Lumbar strengthening exercise in lower-limb amputees with chronic low back pain resulted in decreased pain and increased lumbar extensor strength. The lumbar strengthening exercise program is very effective for lower-limb amputees with chronic low back pain.

A wearable skin stretch haptic feedback device: Towards improving balance control in lower limb amputees.

PubMed

Husman, M A B; Maqbool, H F; Awad, M I; Abouhossein, A; Dehghani-Sanij, A A

2016-08-01

Haptic feedback to lower limb amputees is essential to maximize the functionality of a prosthetic device by providing information to the user about the interaction with the environment and the position of the prostheses in space. Severed sensory pathway and the absence of connection between the prosthesis and the Central Nervous System (CNS) after lower limb amputation reduces balance control, increases visual dependency and increases risk of falls among amputees. This work describes the design of a wearable haptic feedback device for lower limb amputees using lateral skin-stretch modality intended to serve as a feedback cue during ambulation. A feedback scheme was proposed based on gait event detection for possible real-time postural adjustment. Preliminary perceptual test with healthy subjects in static condition was carried out and the results indicated over 98% accuracy in determining stimuli location around the upper leg region, suggesting good perceptibility of the delivered stimuli.

Ultrasonographic assessment of the quadriceps muscle and femoral cartilage in transtibial amputees using different prostheses.

PubMed

Şahin Onat, Şule; Malas, Fevziye Ünsal; Öztürk, Gökhan Tuna; Akkaya, Nuray; Kara, Murat; Özçakar, Levent

2016-08-01

In patients with lower limb amputations, gait alteration, increased loading on the intact extremity, and use of prosthesis may lead to joint degeneration. To explore the effects of prosthesis type on quadriceps muscle and distal femoral cartilage thicknesses in transtibial amputees. A cross-sectional study. A total of 38 below-knee amputees were enrolled in the study, of which 13 patients were using vacuum system type prosthesis and 25 patients were using silicon liner pin system prosthesis. Patients' femoral cartilage and quadriceps muscle thickness measurements were performed using musculoskeletal ultrasound. When compared with the intact sides, cartilage and rectus femoris, vastus intermedius, and vastus medialis muscle thickness values were significantly decreased on the amputee sides (all p < 0.05). Clinical characteristics and ultrasound measurements were similar between the two groups except the lateral and medial femoral condyle thicknesses, thinner in the silicon liner pin system users (both p < 0.05). The distal femoral cartilage and quadriceps muscle thicknesses were found to be decreased on the amputated sides, and the negative impact on the cartilage seemed to be worse in the silicon liner pin system users. This study might provide another argument as regards the preference of vacuum system type prosthesis to prevent possible knee osteoarthritis due to cartilage thinning in adult transtibial amputees. © The International Society for Prosthetics and Orthotics 2015.

Mechanisms of Gait Asymmetry Due to Push-Off Deficiency in Unilateral Amputees.

PubMed

Adamczyk, Peter Gabriel; Kuo, Arthur D

2015-09-01

Unilateral lower-limb amputees exhibit asymmetry in many gait features, such as ground force, step time, step length, and joint mechanics. Although these asymmetries result from weak prosthetic-side push-off, there is no proven mechanistic explanation of how that impairment propagates to the rest of the body. We used a simple dynamic walking model to explore possible consequences of a unilateral impairment similar to that of a transtibial amputee. The model compensates for reduced push-off work from one leg by performing more work elsewhere, for example during the middle of stance by either or both legs. The model predicts several gait abnormalities, including slower forward velocity of the body center-of-mass during intact-side stance, greater energy dissipation in the intact side, and more positive work overall. We tested these predictions with data from unilateral transtibial amputees (N = 11) and nonamputee control subjects (N = 10) walking on an instrumented treadmill. We observed several predicted asymmetries, including forward velocity during stance phases and energy dissipation from the two limbs, as well as greater work overall. Secondary adaptations, such as to reduce discomfort, may exacerbate asymmetry, but these simple principles suggest that some asymmetry may be unavoidable in cases of unilateral limb loss.

Technology Efficacy in Active Prosthetic Knees for Transfemoral Amputees: A Quantitative Evaluation

PubMed Central

El-Sayed, Amr M.; Abu Osman, Noor Azuan

2014-01-01

Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees' gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system's efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on the percentage of amputees' gait deviation from normal gait profile points. The results identified particular components that contributed closest to normal gait parameters. However, the conclusion is limitedly extendable due to the small number of studies. Thus, more clinical validation of the active prosthetic knee technology is needed to better understand the extent of contribution of each component to the most functional development. PMID:25110727

Technology efficacy in active prosthetic knees for transfemoral amputees: a quantitative evaluation.

PubMed

El-Sayed, Amr M; Hamzaid, Nur Azah; Abu Osman, Noor Azuan

2014-01-01

Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees' gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system's efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on the percentage of amputees' gait deviation from normal gait profile points. The results identified particular components that contributed closest to normal gait parameters. However, the conclusion is limitedly extendable due to the small number of studies. Thus, more clinical validation of the active prosthetic knee technology is needed to better understand the extent of contribution of each component to the most functional development.

Supervised exercise improves cutaneous reinnervation capacity in metabolic syndrome patients.

PubMed

Singleton, J Robinson; Marcus, Robin L; Lessard, Margaret K; Jackson, Justin E; Smith, A Gordon

2015-01-01

Unmyelinated cutaneous axons are vulnerable to physical and metabolic injury, but also capable of rapid regeneration. This balance may help determine risk for peripheral neuropathy associated with diabetes or metabolic syndrome. Capsaicin application for 48 hours induces cutaneous fibers to die back into the dermis. Regrowth can be monitored by serial skin biopsies to determine intraepidermal nerve fiber density (IENFD). We used this capsaicin axotomy technique to examine the effects of exercise on cutaneous regenerative capacity in the setting of metabolic syndrome. Baseline ankle IENFD and 30-day cutaneous regeneration after thigh capsaicin axotomy were compared for participants with type 2 diabetes (n = 35) or metabolic syndrome (n = 32) without symptoms or examination evidence of neuropathy. Thirty-six participants (17 with metabolic syndrome) then joined twice weekly observed exercise and lifestyle counseling. Axotomy regeneration was repeated in month 4 during this intervention. Baseline distal leg IENFD was significantly reduced for both metabolic syndrome and diabetic groups. With exercise, participants significantly improved exercise capacity and lower extremity power. Following exercise, 30-day reinnervation rate improved (0.051 ± 0.027 fibers/mm/day before vs 0.072 ± 0.030 after exercise, p = 0.002). Those who achieved improvement in more metabolic syndrome features experienced a greater degree of 30-day reinnervation (p < 0.012). Metabolic syndrome was associated with reduced baseline IENFD and cutaneous regeneration capacity comparable to that seen in diabetes. Exercise-induced improvement in metabolic syndrome features increased cutaneous regenerative capacity. The results underscore the potential benefit to peripheral nerve function of a behavioral modification approach to metabolic improvement. © 2014 American Neurological Association.

Innovative Use of Thighplasty to Improve Prosthesis Fit and Function in a Transfemoral Amputee.

PubMed

Kuiken, Todd A; Fey, Nicholas P; Reissman, Timothy; Finucane, Suzanne B; Dumanian, Gregory A

2018-01-01

Excess residual limb fat is a common problem that can impair prosthesis control and negatively impact gait. In the general population, thighplasty and liposuction are commonly performed for cosmetic reasons but not specifically to improve function in amputees. The objective of this study was to determine if these procedures could enhance prosthesis fit and function in an overweight above-knee amputee. We evaluated the use of these techniques on a 50-year-old transfemoral amputee who was overweight. The patient underwent presurgical imaging and tests to measure her residual limb tissue distribution, socket-limb interface stiffness, residual femur orientation, lower-extremity function, and prosthesis satisfaction. A medial thighplasty procedure with circumferential liposuction was performed, during which 2,812 g (6.2 lbs.) of subcutaneous fat and skin was removed from her residual limb. Imaging was repeated 5 months postsurgery; functional assessments were repeated 9 months postsurgery. The patient demonstrated notable improvements in socket fit and in performing most functional and walking tests. Her comfortable walking speed increased 13.3%, and her scores for the Sit-to-Stand and Four Square Step tests improved over 20%. Femur alignment in her socket changed from 8.13 to 4.14 degrees, and analysis showed a marked increase in the socket-limb interface stiffness. This study demonstrates the potential of using a routine plastic surgery procedure to modify the intrinsic properties of the limb and to improve functional outcomes in overweight or obese transfemoral amputees. This technique is a potentially attractive option compared with multiple reiterations of sockets, which can be time-consuming and costly.

Embryologic innervation of the rat laryngeal musculature--a model for investigation of recurrent laryngeal nerve reinnervation.

PubMed

Pitman, Michael J; Berzofsky, Craig E; Alli, Opeyemi; Sharma, Sansar

2013-12-01

Optimal management of vocal fold paralysis would entail recurrent laryngeal nerve (RLN) reinnervation resulting in normal vocal fold motion. Unfortunately, RLN reinnervation currently results in a nonfunctional vocal fold due to synkinetic reinnervation. Therapeutic interventions that guide regenerating axons back to the appropriate muscle would prevent synkinesis and restore vocal fold and glottal function. The initial step toward developing these therapies is the elucidation of the embryologic innervation of the larynx. This study aimed to identify the age of occurrence, timing, and pattern of embryologic innervation of the rat larynx, hypothesizing that differences in these parameters exist between distinct laryngeal muscles. Descriptive anatomic study. The larynx of rats aged embryologic day (E) 15, 16, 17, 19, and 21 were harvested and then sectioned. Two rats were used for each age. Sections were colabeled with neuronal class III β-tubulin polyclonal antibody to identify the presence of axons and alexa 488 conjugate α-bungarotoxin to identify the presence of motor endplates. The age at which axons and motor endplates were first present was noted. The position and pattern of the axons and motor endplates was recorded in relation to each other as well as the musculoskeletal anatomy of the larynx. The time at which axons appeared to innervate the medial thyroarytenoid (MTA) muscle, lateral thyroarytenoid (LTA) muscle, and the posterior cricoarytenoid (PCA) muscle was documented. Findings in the rat suggest the RLN reaches the larynx and begins branching by E15. Axons branch dorsally first and reach the PCA muscle before the other muscles. Branching toward the MTA muscle occurs only after axons have reached the LTA muscle. By E19, RLN axons have been guided to and selected their respective muscles with formation of neuromuscular junctions (NMJs) in the PCA, LTA and MTA muscles, though the formation of NMJs in the MTA muscle was comparatively delayed. This study

Kinetic and Kinematic Differences in a Golf Swing in One and Both Lower Limb Amputees

PubMed Central

Stastny, Petr; Maszczyk, Adam; Tománková, Kristina; Kubový, Petr; Richtrová, Michaela; Otáhal, Jakub; Čichoň, Rostislav; Mostowik, Aleksandra; Żmijewski, Piotr; Cięszczyk, Paweł

2015-01-01

Amputee golfers need to cope with the absence of sole proprioception, a decreased range of swing motion and other factors which should be recognized for training purposes. The aim of this study was to determine the kinetic and kinematic differences in the golf swing in one leg and two legs amputees. The participants consisted of two males and one female at a professional or amateur level with a different degree of disability. Each participant was taped by 3D markers and performed five golf swings with the iron 6. The intraclass correlation coefficient (ICC) did not vary between individuals in kinematics, however, it was low in kinetic variables of two leg amputees. The Kendal rank correlation showed a significant relationship between the level of amputation and a large number of kinetic and kinematic variables such as X factor, O factor, S factor and individual body angles. The fluency and similarity of the golf swing did not depend on the level of amputation. One lower limb amputation did not seem to increase movement variability contrary to two lower limb amputation. The most variable parameter was a weight-shift in all golfers. The takeaway and horizontal force angle depended on the level of amputation rather than individual technique, thus, their modification by training may be difficult. Estimation of golf swing „mistakes” in amputees in respect to the leading arm in an early follow or late follow position appeared to be useless. PMID:26834871

Kinetic and Kinematic Differences in a Golf Swing in One and Both Lower Limb Amputees.

PubMed

Stastny, Petr; Maszczyk, Adam; Tománková, Kristina; Kubový, Petr; Richtrová, Michaela; Otáhal, Jakub; Čichoň, Rostislav; Mostowik, Aleksandra; Żmijewski, Piotr; Cięszczyk, Paweł

2015-11-22

Amputee golfers need to cope with the absence of sole proprioception, a decreased range of swing motion and other factors which should be recognized for training purposes. The aim of this study was to determine the kinetic and kinematic differences in the golf swing in one leg and two legs amputees. The participants consisted of two males and one female at a professional or amateur level with a different degree of disability. Each participant was taped by 3D markers and performed five golf swings with the iron 6. The intraclass correlation coefficient (ICC) did not vary between individuals in kinematics, however, it was low in kinetic variables of two leg amputees. The Kendal rank correlation showed a significant relationship between the level of amputation and a large number of kinetic and kinematic variables such as X factor, O factor, S factor and individual body angles. The fluency and similarity of the golf swing did not depend on the level of amputation. One lower limb amputation did not seem to increase movement variability contrary to two lower limb amputation. The most variable parameter was a weight-shift in all golfers. The takeaway and horizontal force angle depended on the level of amputation rather than individual technique, thus, their modification by training may be difficult. Estimation of golf swing "mistakes" in amputees in respect to the leading arm in an early follow or late follow position appeared to be useless.

Longitudinal kinematic and kinetic adaptations to obstacle crossing in recent lower limb amputees.

PubMed

Barnett, Cleveland T; Polman, Remco C J; Vanicek, Natalie

2014-12-01

Obstacle crossing is an important activity of daily living, necessary to avoid tripping or falling, although it is not fully understood how transtibial amputees adapt to performing this activity of daily living following discharge from rehabilitation. The objective of this study was to investigate the longitudinal adaptations in obstacle crossing in transtibial amputees post-discharge from rehabilitation. Longitudinal repeated measures. Seven unilateral transtibial amputees crossed an obstacle 0.1m high positioned along a walkway while kinematic and kinetic data were recorded at 1, 3 and 6 months post-discharge. At 6 months post-discharge, walking velocity had increased (0.17 m.s(-1)) with most participants self-selecting an intact lead limb preference. During swing phase, peak knee flexion (p = 0.03) and peak knee power absorption (K4; p = 0.01) were greater with an intact versus affected lead limb preference. Having crossed the obstacle, intact limb peak ankle power generation in pre-swing (A2; p = 0.01) and knee power absorption (K3; p = 0.05) during stance phase were greater when compared to the affected limb. Obstacle crossing improved, although a greater reliance on intact limb function was highlighted. Results suggested that further improvements to locomotor performance may be obtained by increasing affected limb knee range of motion and concentric and eccentric strength of the knee extensors and flexors. The novel objective data from this study establish an understanding of how recent transtibial amputees adapt to performing obstacle crossing following discharge from rehabilitation. This allows for evidence-based clinical interventions to be developed, aimed at optimising biomechanical function, thus improving overall locomotor performance and perhaps subsequent quality of life. © The International Society for Prosthetics and Orthotics 2013.

Vocal fold medialization in children: injection laryngoplasty, thyroplasty, or nerve reinnervation?

PubMed

Sipp, J Andrew; Kerschner, Joseph E; Braune, Nicole; Hartnick, Christopher J

2007-08-01

To review surgical interventions for pediatric unilateral vocal fold immobility (UVFI). Retrospective medical chart review. Two tertiary academic centers. All children who underwent vocal fold medialization for dysphonia, with or without aspiration, from January 2004 to September 2006. Injection laryngoplasty, ansa cervicalis-recurrent laryngeal nerve anastomosis, or thyroplasty. Age, sex, intervention, etiology, time from onset of UVFI to surgery, subjective success in improving voice, subjective duration of improvement, and complications. Twenty-seven procedures were performed in 15 patients (mean age, 10.6 years). Nineteen injection laryngoplasties, 3 thyroplasties (1 bilateral), 2 ansa cervicalis-recurrent laryngeal nerve reinnervation procedures, 1 adduction arytenoidopexy, and 1 cricothyroid joint subluxation were performed. Causes of UVFI included thoracic surgery in 6 cases (40%), prolonged intubation in 4 (26%), central nervous system neoplasm in 3 (20%), unknown etiology in 1 (7%), and anoxic brain injury in 1 (7%). The mean duration from onset of symptoms to treatment was 47 months. There was 1 surgical complication (postoperative aspiration pneumonia following thyroplasty while the patient was under local anesthesia). Parents reported a satisfactory outcome in all cases. Injection laryngoplasty, thyroplasty, and nerve reinnervation can be performed in pediatric patients with good outcomes and an acceptable safety profile. This article describes the experiences of 2 institutions with phonosurgery for UVFI in children and provides insight into the advantages and disadvantages of each procedure. Prospective studies, with validated quality-of-life measurements, are needed to greater clarify the role of different types of phonosurgery in children with UVFI.

Trans-tibial amputee gait: time-distance parameters and EMG activity.

PubMed

Isakov, E; Keren, O; Benjuya, N

2000-12-01

Gait analysis of trans-tibial (TT) amputees discloses asymmetries in gait parameters between the amputated and sound legs. The present study aimed at outlining differences between both legs with regard to kinematic parameters and activity of the muscles controlling the knees. The gait of 14 traumatic TT amputees, walking at a mean speed of 74.96 m/min, was analysed by means of an electronic walkway, video camera, and portable electromyography system. Results showed differences in kinematic parameters. Step length, step time and swing time were significantly longer, while stance time and single support time were significantly shorter on the amputated side. A significant difference was also found between knee angle in both legs at heel strike. The biceps femoris/vastus medialis ratio in the amputated leg, during the first half of stance phase, was significantly higher when compared to the same muscle ratio in the sound leg. This difference was due to the higher activity of the biceps femoris, almost four times higher than the vastus medialis in the amputated leg. The observed differences in time-distance parameters are due to stiffness of the prosthesis ankle (the SACH foot) that impedes the normal forward advance of the amputated leg during the first half of stance. The higher knee flexion at heel strike is due to the necessary socket alignment. Unlike in the sound leg, the biceps femoris in the amputated leg reaches maximal activity during the first half of stance, cocontracting with the vastus medialis, to support body weight on the amputated leg. The obtained data can serve as a future reference for evaluating the influence of new prosthetic components on the quality of TT amputee's gait.

Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage.

PubMed

Verin, Eric; Morelot-Panzini, Capucine; Gonzalez-Bermejo, Jesus; Veber, Benoit; Perrouin Verbe, Brigitte; Soudrie, Brigitte; Leroi, Anne Marie; Marie, Jean Paul; Similowski, Thomas

2017-10-01

The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18-24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications.

Apparent motion perception in lower limb amputees with phantom sensations: "obstacle shunning" and "obstacle tolerance".

PubMed

Saetta, Gianluca; Grond, Ilva; Brugger, Peter; Lenggenhager, Bigna; Tsay, Anthony J; Giummarra, Melita J

2018-03-21

Phantom limbs are the phenomenal persistence of postural and sensorimotor features of an amputated limb. Although immaterial, their characteristics can be modulated by the presence of physical matter. For instance, the phantom may disappear when its phenomenal space is invaded by objects ("obstacle shunning"). Alternatively, "obstacle tolerance" occurs when the phantom is not limited by the law of impenetrability and co-exists with physical objects. Here we examined the link between this under-investigated aspect of phantom limbs and apparent motion perception. The illusion of apparent motion of human limbs involves the perception that a limb moves through or around an object, depending on the stimulus onset asynchrony (SOA) for the two images. Participants included 12 unilateral lower limb amputees matched for obstacle shunning (n = 6) and obstacle tolerance (n = 6) experiences, and 14 non-amputees. Using multilevel linear models, we replicated robust biases for short perceived trajectories for short SOA (moving through the object), and long trajectories (circumventing the object) for long SOAs in both groups. Importantly, however, amputees with obstacle shunning perceived leg stimuli to predominantly move through the object, whereas amputees with obstacle tolerance perceived leg stimuli to predominantly move around the object. That is, in people who experience obstacle shunning, apparent motion perception of lower limbs was not constrained to the laws of impenetrability (as the phantom disappears when invaded by objects), and legs can therefore move through physical objects. Amputees who experience obstacle tolerance, however, had stronger solidity constraints for lower limb apparent motion, perhaps because they must avoid co-location of the phantom with physical objects. Phantom limb experience does, therefore, appear to be modulated by intuitive physics, but not in the same way for everyone. This may have important implications for limb experience post

Optimization of prosthetic foot stiffness to reduce metabolic cost and intact knee loading during below-knee amputee walking: a theoretical study.

PubMed

Fey, Nicholas P; Klute, Glenn K; Neptune, Richard R

2012-11-01

Unilateral below-knee amputees develop abnormal gait characteristics that include bilateral asymmetries and an elevated metabolic cost relative to non-amputees. In addition, long-term prosthesis use has been linked to an increased prevalence of joint pain and osteoarthritis in the intact leg knee. To improve amputee mobility, prosthetic feet that utilize elastic energy storage and return (ESAR) have been designed, which perform important biomechanical functions such as providing body support and forward propulsion. However, the prescription of appropriate design characteristics (e.g., stiffness) is not well-defined since its influence on foot function and important in vivo biomechanical quantities such as metabolic cost and joint loading remain unclear. The design of feet that improve these quantities could provide considerable advancements in amputee care. Therefore, the purpose of this study was to couple design optimization with dynamic simulations of amputee walking to identify the optimal foot stiffness that minimizes metabolic cost and intact knee joint loading. A musculoskeletal model and distributed stiffness ESAR prosthetic foot model were developed to generate muscle-actuated forward dynamics simulations of amputee walking. Dynamic optimization was used to solve for the optimal muscle excitation patterns and foot stiffness profile that produced simulations that tracked experimental amputee walking data while minimizing metabolic cost and intact leg internal knee contact forces. Muscle and foot function were evaluated by calculating their contributions to the important walking subtasks of body support, forward propulsion and leg swing. The analyses showed that altering a nominal prosthetic foot stiffness distribution by stiffening the toe and mid-foot while making the ankle and heel less stiff improved ESAR foot performance by offloading the intact knee during early to mid-stance of the intact leg and reducing metabolic cost. The optimal design also

Vibrotactile stimulation promotes embodiment of an alien hand in amputees with phantom sensations.

PubMed

D'Alonzo, Marco; Clemente, Francesco; Cipriani, Christian

2015-05-01

Tactile feedback is essential to intuitive control and to promote the sense of self-attribution of a prosthetic limb. Recent findings showed that amputees can be tricked to experience this embodiment, when synchronous and modality-matched stimuli are delivered to biological afferent structures and to an alien rubber hand. Hence, it was suggested to exploit this effect by coupling touch sensors in a prosthesis to an array of haptic tactile stimulators in the prosthetic socket. However, this approach is not clinically viable due to physical limits of current haptic devices. To address this issue we have proposed modality-mismatched stimulation and demonstrated that this promotes self-attribution of an alien hand on normally limbed subjects. In this work we investigated whether similar effects could be induced in transradial amputees with referred phantom sensations in a series of experiments fashioned after the Rubber Hand Illusion using vibrotactile stimulators. Results from three independent measures of embodiment demonstrated that vibrotactile sensory substitution elicits body-ownership of a rubber hand in transradial amputees. These results open up promising possibilities in this field; indeed miniature, safe and inexpensive vibrators could be fitted into commercially available prostheses and sockets to induce the illusion every time the prosthesis manipulates an object.

Increasing ankle push-off work with a powered prosthesis does not necessarily reduce metabolic rate for transtibial amputees.

PubMed

Quesada, Roberto E; Caputo, Joshua M; Collins, Steven H

2016-10-03

Amputees using passive ankle-foot prostheses tend to expend more metabolic energy during walking than non-amputees, and reducing this cost has been a central motivation for the development of active ankle-foot prostheses. Increased push-off work at the end of stance has been proposed as a way to reduce metabolic energy use, but the effects of push-off work have not been tested in isolation. In this experiment, participants with unilateral transtibial amputation (N=6) walked on a treadmill at a constant speed while wearing a powered prosthesis emulator. The prosthesis delivered different levels of ankle push-off work across conditions, ranging from the value for passive prostheses to double the value for non-amputee walking, while all other prosthesis mechanics were held constant. Participants completed six acclimation sessions prior to a data collection in which metabolic rate, kinematics, kinetics, muscle activity and user satisfaction were recorded. Metabolic rate was not affected by net prosthesis work rate (p=0.5; R 2 =0.007). Metabolic rate, gait mechanics and muscle activity varied widely across participants, but no participant had lower metabolic rate with higher levels of push-off work. User satisfaction was affected by push-off work (p=0.002), with participants preferring values of ankle push-off slightly higher than in non-amputee walking, possibly indicating other benefits. Restoring or augmenting ankle push-off work is not sufficient to improve energy economy for lower-limb amputees. Additional necessary conditions might include alternate timing or control, individualized tuning, or particular subject characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of an externally powered prosthetic hook for amputees

NASA Technical Reports Server (NTRS)

Karchak, A., Jr.; Allen, J. R.; Bontrager, E. L.

1973-01-01

The powered hook with trigger finger appears to be a useful adaptation of a terminal device for an amputee when performing vocational activities involving the use of a powered tool requiring a trigger control. The proportional control system includes transducers and amplifiers and appears to have widespread application for control of any external power, whether it be in the orthotic or prosthetic field.

Functional expansion of sensorimotor representation and structural reorganization of callosal connections in lower limb amputees.

PubMed

Simões, Elington L; Bramati, Ivanei; Rodrigues, Erika; Franzoi, Ana; Moll, Jorge; Lent, Roberto; Tovar-Moll, Fernanda

2012-02-29

Previous studies have indicated that amputation or deafferentation of a limb induces functional changes in sensory (S1) and motor (M1) cortices, related to phantom limb pain. However, the extent of cortical reorganization after lower limb amputation in patients with nonpainful phantom phenomena remains uncertain. In this study, we combined functional magnetic resonance (fMRI) and diffusion tensor imaging (DTI) to investigate the existence and extent of cortical and callosal plasticity in these subjects. Nine "painless" patients with lower limb amputation and nine control subjects (sex- and age-matched) underwent a 3-T MRI protocol, including fMRI with somatosensory stimulation. In amputees, we observed an expansion of activation maps of the stump in S1 and M1 of the deafferented hemisphere, spreading to neighboring regions that represent the trunk and upper limbs. We also observed that tactile stimulation of the intact foot in amputees induced a greater activation of ipsilateral S1, when compared with controls. These results demonstrate a functional remapping of S1 in lower limb amputees. However, in contrast to previous studies, these neuroplastic changes do not appear to be dependent on phantom pain but do also occur in those who reported only the presence of phantom sensation without pain. In addition, our findings indicate that amputation of a limb also induces changes in the cortical representation of the intact limb. Finally, DTI analysis showed structural changes in the corpus callosum of amputees, compatible with the hypothesis that phantom sensations may depend on inhibitory release in the sensorimotor cortex.

Transection of Preganglionic Axons Leads to CNS Neuronal Plasticity Followed by Survival and Target Reinnervation

PubMed Central

Coulibaly, Aminata P.; Gannon, Sean M.; Hawk, Kiel; Walsh, Brian F.; Isaacson, Lori G.

2013-01-01

The goals of the present study were to investigate the changes in sympathetic preganglionic neurons following transection of distal axons in the cervical sympathetic trunk (CST) that innervate the superior cervical ganglion (SCG) and to assess changes in the protein expression of brain derived neurotrophic factor (BDNF) and its receptor TrkB in the thoracic spinal cord. . At 1 week, a significant decrease in soma volume and reduced soma expression of choline acetyltransferase (ChAT) in the intermediolateral cell column (IML) of T1 spinal cord were observed, with both ChAT-ir and non-immunoreactive neurons expressing the injury marker activating transcription factor 3. . These changes were transient, and at later time points, ChAT expression and soma volume returned to control values and the number of ATF3 neurons declined. No evidence for cell loss or neuronal apoptosis was detected at any time point. Protein levels of BDNF and/or full length TrkB in the spinal cord were increased throughout the survival period. In the SCG, both ChAT-ir axons and ChAT protein remained decreased at 16 weeks, but were increased compared to the 10 week time point. These results suggest that though IML neurons show reduced ChAT expression and cell volume at 1 week following CST transection, at later time points, the neurons recovered and exhibited no significant signs of neurodegeneration. The alterations in BDNF and/or TrkB may have contributed to the survival of the IML neurons and the recovery of ChAT expression, as well as to the reinnervation of the SCG. PMID:23891533

Somatic and movement inductions phantom limb in non-amputees

NASA Astrophysics Data System (ADS)

Casas, D. M.; Gentiletti, G. G.; Braidot, A. A.

2016-04-01

The illusion of the mirror box is a tool for phantom limb pain treatment; this article proposes the induction of phantom limb syndrome on non-amputees upper limb, with a neurological trick of the mirror box. With two study situations: a) Somatic Induction is a test of the literature reports qualitatively, and novel proposal b) Motor Induction, which is an objective report by recording surface EEG. There are 3 cases proposed for Motor illusion, for which grasped movement is used: 1) Control: movement is made, 2) illusion: the mirror box is used, and 3) Imagination: no movement is executed; the subject only imagines its execution. Three different tasks are registered for each one of them (left hand, right hand, and both of them). In 64% of the subjects for somatic experience, a clear response to the illusion was observed. In the experience of motor illusion, cortical activation is detected in both hemispheres of the primary motor cortex during the illusion, where the hidden hand remains motionless. These preliminary findings in phantom limb on non-amputees can be a tool for neuro-rehabilitation and neuro-prosthesis control training.

Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage

PubMed Central

Morelot-Panzini, Capucine; Gonzalez-Bermejo, Jesus; Veber, Benoit; Perrouin Verbe, Brigitte; Soudrie, Brigitte; Leroi, Anne Marie; Marie, Jean Paul; Similowski, Thomas

2017-01-01

The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18–24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications. PMID:29181382

Challenges of CPD for physiotherapists working as lone practitioners in amputee rehabilitation.

PubMed

Cole, Mary Jane; Morris, Jane; Scammell, Amy

2008-09-01

The aim of this study was to explore the issues around continuing professional development (CPD) for physiotherapists working as lone practitioners in amputee rehabilitation in the United Kingdom (UK). Qualitative method using a phenomenological approach via one to one semi-structured interviews and thematic data analysis. Ten physiotherapists with responsibility for amputee rehabilitation working as lone practitioners in hospitals or specialist centres in the UK. CPD is valued and there is commitment towards the process. Current solutions are identified but there are frustrations around more structured CPD and organizational issues. These include inadequate access to learning opportunities, lack of professional feedback, insufficient time and limited learning skills. There are opportunities for improving CPD through organizational structures but specialist input is recommended to support lone practitioners and managers with the process, e.g., consultant or peripatetic therapists.

Combat amputees' health-related quality of life and psychological outcomes: A brief report from the wounded warrior recovery project.

PubMed

Woodruff, Susan I; Galarneau, Michael R; Sack, Daniel I; McCabe, Cameron T; Dye, Judy L

2017-03-01

This study extends what is known about long-term health-related quality of life (HrQoL) and other psychosocial outcomes (i.e., depression, posttraumatic stress disorder [PTSD]) among US military combat amputees serving in Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn. A total of 63 combat amputees were identified from the Wounded Warrior Recovery Project, a study assessing long-term self-reported HrQoL and psychological outcomes among those wounded during military service. Another 477 service members from the Wounded Warrior Recovery Project were identified as a comparison group (i.e., nonamputees with moderate to severe extremity injuries). After adjusting for age, time since injury, overall injury severity, and traumatic brain injury, amputees had poorer functional HrQoL than those in the nonamputee comparison group overall and in the specific area related to performance of usual activities, and, to some degree, chronic and acute symptoms, and mobility/self-care. On the other hand, depression and PTSD symptoms were not different for the two groups. Results suggest that when assessed over 5 years postinjury, on average, amputees have unique physical and functional limitations, yet do not report greater depression or PTSD symptoms than others seriously injured in combat. It may be that state-of-the-art integrated amputee care that includes support networks and emphasis on adjustment and psychological health may increase successful coping and adjustment, at least to a level that is on par with other types of serious combat injury. Epidemiologic/prognostic study, level III.

Kinetics of transfemoral amputees with osseointegrated fixation performing common activities of daily living.

PubMed

Lee, Winson C C; Frossard, Laurent A; Hagberg, Kerstin; Haggstrom, Eva; Brånemark, Rickard; Evans, John H; Pearcy, Mark J

2007-07-01

Direct anchorage of a lower-limb prosthesis to the bone through an implanted fixation (osseointegration) has been suggested as an excellent alternative for amputees experiencing complications from use of a conventional socket-type prosthesis. However, an attempt needs to be made to optimize the mechanical design of the fixation and refine the rehabilitation program. Understanding the load applied on the fixation is a crucial step towards this goal. The load applied on the osseointegrated fixation of nine transfemoral amputees was measured using a load transducer, when the amputees performed activities which included straight-line level walking, ascending and descending stairs and a ramp as well as walking around a circle. Force and moment patterns along each gait cycle, magnitudes and time of occurrence of the local extrema of the load, as well as impulses were analysed. Managing a ramp and stairs, and walking around a circle did not produce a significant increase (P>0.05) in load compared to straight-line level walking. The patterns of the moment about the medio-lateral axis were different among the six activities which may reflect the different strategies used in controlling the prosthetic knee joint. This study increases the understanding of biomechanics of bone-anchored osseointegrated prostheses. The loading data provided will be useful in designing the osseointegrated fixation to increase the fatigue life and to refine the rehabilitation protocol.

Spatiotemporal Variables of Able-bodied and Amputee Sprinters in Men's 100-m Sprint.

PubMed

Hobara, H; Kobayashi, Y; Mochimaru, M

2015-06-01

The difference in world records set by able-bodied sprinters and amputee sprinters in the men's 100-m sprint is still approximately 1 s (as of 28 March 2014). Theoretically, forward velocity in a 100-m sprint is the product of step frequency and step length. The goal of this study was to examine the hypothesis that differences in the sprint performance of able-bodied and amputee sprinters would be due to a shorter step length rather than lower step frequency. Men's elite-level 100-m races with a total of 36 able-bodied, 25 unilateral and 17 bilateral amputee sprinters were analyzed from the publicly available internet broadcasts of 11 races. For each run of each sprinter, the average forward velocity, step frequency and step length over the whole 100-m distance were analyzed. The average forward velocity of able-bodied sprinters was faster than that of the other 2 groups, but there was no significant difference in average step frequency among the 3 groups. However, the average step length of able-bodied sprinters was significantly longer than that of the other 2 groups. These results suggest that the differences in sprint performance between 2 groups would be due to a shorter step length rather than lower step frequency. © Georg Thieme Verlag KG Stuttgart · New York.

Nutritional profile of the Brazilian Amputee Soccer Team during the precompetition period for the world championship.

PubMed

Innocencio da Silva Gomes, Ainá; Gonçalves Ribeiro, Beatriz; de Abreu Soares, Eliane

2006-10-01

The purpose of this study was to determine the dietary and anthropometric profiles of the Brazilian amputee soccer players during the training period before the world soccer amputee championship, according to their positional roles in the game. Fifteen male athletes participated in the study. Data on height, weight, skinfold thickness, and circumferences were collected to assess nutritional status. Dietary intake was obtained by using 6-d dietary records, analyzed by a Nutrition Support Program for total energy intake, carbohydrates, proteins, lipids, vitamins, and minerals. One-way analysis of variance was used to identify differences in groups (P < 0.05). Midfield players were heavier than the others, and this difference may have been caused by a large quantity of subcutaneous fat. Dietary data showed a low carbohydrate intake and high protein and fat intakes. No athlete met the recommendations for vitamin E, and forward players did not meet recommendations for calcium. Amputee athletes need an individualized nutritional orientation and the lack of information about disabled sports and athletes highlights the need for more studies in this area.

Gait symmetry and regularity in transfemoral amputees assessed by trunk accelerations

PubMed Central

2010-01-01

Background The aim of this study was to evaluate a method based on a single accelerometer for the assessment of gait symmetry and regularity in subjects wearing lower limb prostheses. Methods Ten transfemoral amputees and ten healthy control subjects were studied. For the purpose of this study, subjects wore a triaxial accelerometer on their thorax, and foot insoles. Subjects were asked to walk straight ahead for 70 m at their natural speed, and at a lower and faster speed. Indices of step and stride regularity (Ad1 and Ad2, respectively) were obtained by the autocorrelation coefficients computed from the three acceleration components. Step and stride durations were calculated from the plantar pressure data and were used to compute two reference indices (SI1 and SI2) for step and stride regularity. Results Regression analysis showed that both Ad1 well correlates with SI1 (R2 up to 0.74), and Ad2 well correlates with SI2 (R2 up to 0.52). A ROC analysis showed that Ad1 and Ad2 has generally a good sensitivity and specificity in classifying amputee's walking trial, as having a normal or a pathologic step or stride regularity as defined by means of the reference indices SI1 and SI2. In particular, the antero-posterior component of Ad1 and the vertical component of Ad2 had a sensitivity of 90.6% and 87.2%, and a specificity of 92.3% and 81.8%, respectively. Conclusions The use of a simple accelerometer, whose components can be analyzed by the autocorrelation function method, is adequate for the assessment of gait symmetry and regularity in transfemoral amputees. PMID:20085653

Predict the Medicare Functional Classification Level (K-level) using the Amputee Mobility Predictor in people with unilateral transfemoral and transtibial amputation: A pilot study.

PubMed

Dillon, Michael P; Major, Matthew J; Kaluf, Brian; Balasanov, Yuri; Fatone, Stefania

2018-04-01

While Amputee Mobility Predictor scores differ between Medicare Functional Classification Levels (K-level), this does not demonstrate that the Amputee Mobility Predictor can accurately predict K-level. To determine how accurately K-level could be predicted using the Amputee Mobility Predictor in combination with patient characteristics for persons with transtibial and transfemoral amputation. Prediction. A cumulative odds ordinal logistic regression was built to determine the effect that the Amputee Mobility Predictor, in combination with patient characteristics, had on the odds of being assigned to a particular K-level in 198 people with transtibial or transfemoral amputation. For people assigned to the K2 or K3 level by their clinician, the Amputee Mobility Predictor predicted the clinician-assigned K-level more than 80% of the time. For people assigned to the K1 or K4 level by their clinician, the prediction of clinician-assigned K-level was less accurate. The odds of being in a higher K-level improved with younger age and transfemoral amputation. Ordinal logistic regression can be used to predict the odds of being assigned to a particular K-level using the Amputee Mobility Predictor and patient characteristics. This pilot study highlighted critical method design issues, such as potential predictor variables and sample size requirements for future prospective research. Clinical relevance This pilot study demonstrated that the odds of being assigned a particular K-level could be predicted using the Amputee Mobility Predictor score and patient characteristics. While the model seemed sufficiently accurate to predict clinician assignment to the K2 or K3 level, further work is needed in larger and more representative samples, particularly for people with low (K1) and high (K4) levels of mobility, to be confident in the model's predictive value prior to use in clinical practice.

Perspiration Thresholds and Secure Suspension for Lower Limb Amputees in Demanding Environments

DTIC Science & Technology

2015-10-01

VAPSHCS) site, fabricating custom, moisture-wicking textile sock with a proximal elastomeric seal, fabricating prosthetic sockets, fabricating electronic...Aims: This research has two specific aims: (1) determine if lower limb amputees are willing to use smart activity monitors as part of their daily life

The fate of neurotization techniques on reinnervation after denervation of the gastrocnemius muscle: an experimental study.

PubMed

Askar, I; Sabuncuoglu, B T; Yormuk, E; Saray, A

2001-07-01

In nerve injuries, if it is not possible to reinnervate muscle by using neurorrhaphy and nerve grafting technique, reinnervation should be provided by the use of neuroization-directly implanting motor nerve into muscle. A comparative study of three techniques of neurotization is presented in rabbits. In this experimental study, a total of 40 white New Zealand rabbits were used and divided into four groups, each including 10 rabbits. In the first group (control--Group 1), only surgical exposure of the gastrocnemius muscle, main muscle nerve (tibial nerve), and peroneal nerve was done, without any injury to the nerves. In the second group (direct neurotization group--Group 2), the tibial nerve was transected, and the peroneal nerve, which had already been divided into fascicles, was implanted into the lateral head of the gastrocnemius muscle aneural zone. In the third group (dual neurotization group--Group 3), the tibial nerve which had been transected and re-anastomosed, and the peroneal nerve were implanted into the lateral head of the gastrocnemius muscle. In the last experimental group (hyperneurotization group--Group 4), fascicles of the peroneal nerve were implanted into the lateral head of the gastrocnemius, preserving the tibial nerve. Six months later, changes in the histologic pattern and the functional recovery of the gastrocnemius muscle were investigated. It was found that functional recovery was achieved in all neurotization groups. Groups with the tibial nerve transected had less muscular weights than those of groups with the tibial nerve intact. EMG recordings showed that polyphasic and late potentials were frequently seen in groups with the tibial nerve transected. Degeneration and regeneration of myofibrils was observed in such groups as well. New motor end-plates, including vesicles, were formed in a scattered manner in all neurotization groups. As a result, the authors conclude that direct and dual neurotization techniques are useful in peripheral

Use of prostheses in lower limb amputee patients due to peripheral arterial disease

PubMed Central

Chamlian, Therezinha Rosane

2014-01-01

Objective To evaluate the indication of prosthesis during rehabilitation and the maintenance of their use or abandonment rate after discharge, as well as mortality of lower limb amputees due to peripheral arterial disease. Methods A retrospective and cross-sectional study carried out with lower limb amputee patients, at transfemoral and transtibial levels, due to vascular conditions. The sample was composed of 310 patients (205 men, 105 women, mean age 61.8 years), transfemoral (142) and transtibial (150) levels, unilateral or bilateral (18). A total of 217 were fitted with prosthesis and 93 did not. Nonparametric statistical tests with equality of two proportions, 95% confidence interval and p value <0,05 were used. Results Out of 195 patients we contacted, 151 were fitted with prosthesis and 44 not. Of those that were fitted with prosthesis, 54 still use it, 80 abandoned and 17 died. In the group without prosthesis, 27 were on wheelchair and 17 died. Mortality is statistically higher among patients who were not fitted with prosthesis and 34 death occur, on average, 3.91 years after amputation. Survival time of patients who were not fitted with prosthesis was smaller than those were fitted. Conclusion The use of prosthesis in lower limb amputees, due to vascular conditions, during rehabilitation is high. However, maintenance of prosthesis is not frequent after discharge. Early and high mortality is observed mainly among diabetic patients. PMID:25628194

Current perspective on assessment of human body proportions of relevance to amputees.

PubMed

Osterkamp, L K

1995-02-01

Weights of segmental components of the human body are important when evaluating the nutritional status of an amputee. Original standards for components were compiled in 1889 using three male cadavers. Since that time, studies of living subjects have shown men and women to be similar in percentage weight of body components. Cadaver data from 1955 and 1969, which were based on 21 male subjects, showed that human bodies carry greater weight in the head and torso and less weight in legs and arms than indicated by the earlier data. Some differences in component weight may be attributable to ethnicity and aging, but further research is needed to define these differences. The 1955 and 1969 data--whether the result of larger sample size, ethnic differences, or actual change in human body proportions over a 60-year period--are different from the standards for body proportions in the 1889 data, which are presently used, and should be incorporated into the assessment of weight status of amputees.

Normal body scheme and absent phantom limb experience in amputees while dreaming.

PubMed

Alessandria, Maria; Vetrugno, Roberto; Cortelli, Pietro; Montagna, Pasquale

2011-12-01

While dreaming amputees often experience a normal body image and the phantom limb may not be present. However, dreaming experiences in amputees have mainly been collected by questionnaires. We analysed the dream reports of amputated patients with phantom limb collected after awakening from REM sleep during overnight videopolysomnography (VPSG). Six amputated patients underwent overnight VPSG study. Patients were awakened during REM sleep and asked to report their dreams. Three patients were able to deliver an account of a dream. In all dreaming recalls, patients reported that the amputated limbs were intact and completely functional and they no longer experienced phantom limb sensations. Phantom limb experiences, that during wake result from a conflict between a pre-existing body scheme and the sensory information on the missing limb, were suppressed during sleep in our patients in favour of the image of an intact body accessed during dream. Copyright © 2011 Elsevier Inc. All rights reserved.

Somatotopical feedback versus non-somatotopical feedback for phantom digit sensation on amputees using electrotactile stimulation.

PubMed

Zhang, Dingguo; Xu, Heng; Shull, Peter B; Liu, Jianrong; Zhu, Xiangyang

2015-05-02

Transcutaneous electrical stimulation can provide amputees with tactile feedback for better manipulating an advanced prosthesis. In general, there are two ways to transfer the stimulus to the skin: somatotopical feedback (SF) that stimulates the phantom digit somatotopy on the stump and non-somatotopical feedback (NF) that stimulates other positions on the human body. To investigate the difference between SF and NF, electrotactile experiments were conducted on seven amputees. Electrical stimulation was applied via a complete phantom map to the residual limb (SF) and to the upper arm (NF) separately. The behavior results of discrimination accuracy and response time were used to examine: 1) performance differences between SF and NF for discriminating position, type and strength of tactile feedback; 2) performance differences between SF and NF for one channel (1C), three channels (3C), and five channels (5C). NASA-TLX standardized testing was used to determine differences in mental workload between SF and NF. The grand-averaged discrimination accuracy for SF was 6% higher than NF, and the average response time for SF was 600 ms faster than NF. SF is better than NF for position, type, strength, and the overall modality regarding both accuracy and response time except for 1C modality (p<0.001). Among the six modalities of stimulation channels, performance of 1C/SF was the best, which was similar to that of 1C/NF and 3C/SF; performance of 3C/NF was similar to that of 5C/SF; performance of 5C/NF was the worst. NASA-TLX scores indicated that mental workload increased as the number of stimulation channels increased. We quantified the difference between SF and NF, and the influence of different number of stimulation channels. SF was better than NF in general, but the practical issues such as the limited area of stumps could constrain the use of SF. We found that more channels increased the amount and richness of information to the amputee while fewer channels resulted in

Transcranial direct current stimulation versus user training on improving online myoelectric control for amputees

NASA Astrophysics Data System (ADS)

Pan, Lizhi; Zhang, Dingguo; Jiang, Ning; Sheng, Xinjun; Zhu, Xiangyang

2017-08-01

Objective. Transcranial direct current stimulation (tDCS) and user training (UT) are two types of methods to improve myoelectric control performance for amputees. In this study, we compared the independent effect between tDCS and UT, and investigated the combined effect of tDCS and UT. Approach. An online paradigm of simultaneous and proportional control (SPC) based on electromyography (EMG) was adopted. The proposed experiments were conducted on six naïve unilateral trans-radial amputees. The subjects each received three types of 20 min interventions: active tDCS with motor training (tDCS  +  UT), active tDCS with quiet sitting (tDCS), and sham tDCS with motor training (UT). The interventions were applied at one week intervals in a randomized order. The subjects performed online control of a feedback arrow with two degrees of freedom (DoFs) to accomplish target reaching motor tasks in pre-sessions and post-sessions. We compared the performance, measured by completion rate, completion time, and efficiency coefficient, between pre-sessions and post-sessions. Main results. The results showed that the intervention tDCS  +  UT and tDCS significantly improved the online SPC performance (i.e. improved the completion rate; reduced the completion time; and improved the efficiency coefficient), while intervention UT did not significantly change the performance. The results also showed that the online SPC performance after intervention tDCS  +  UT and tDCS was not significantly different, but both were significantly better than that after intervention UT. Significance. tDCS could be an effective intervention to improve the online SPC performance in a short time.

Relief of knee flexion contracture and gait improvement following adaptive training for an assist device in a transtibial amputee: A case study.

PubMed

Kim, Sol-Bi; Ko, Chang-Yong; Son, Jinho; Kang, Sungjae; Ryu, Jeicheong; Mun, Museong

2017-01-01

Management of a knee contracture is important for regaining gait ability in transtibial amputees. However, there has been little study of prosthesis training for enhancing mobility and improving range of motion in cases of restricted knee extension. This study aimed to evaluate the effects of adaptive training for an assist device (ATAD) for a transtibial amputee with a knee flexion contracture (KFC). A male transtibial amputee with KFC performed 4 months of ATAD with a multidisciplinary team. During the ATAD, the passive range of motion (PROM) in the knee, amputee mobility predictor (AMP) assessment, center of pressure (COP) on a force plate-equipped treadmill, gait features determined by three-dimensional motion analysis, and Short-Form 36 Item Health Survey (SF-36) scores were evaluated. Following ATAD, PROM showed immediate improvement (135.6 ± 2.4° at baseline, 142.5 ± 1.7° at Step 1, 152.1 ± 1.8° at Step 2, 165.8 ± 1.9° at Step 3, and 166.0 ± 1.4° at Step 4); this was followed by an enhanced COP. Gradually, gait features also improved. Additionally, the AMP score (5 at baseline to 29 at Step 4) and K-level (K0 at baseline to K3 at Step 4) increased after ATAD. Along with these improvements, the SF-36 score also improved. ATAD could be beneficial for transtibial amputees by relieving knee contractures and improving gait.

Compensatory changes accompanying chronic forced use of the nondominant hand by unilateral amputees.

PubMed

Philip, Benjamin A; Frey, Scott H

2014-03-05

Amputation of the dominant hand forces patients to use the nondominant hand exclusively, including for tasks (e.g., writing and drawing) that were formerly the sole domain of the dominant hand. The behavioral and neurological effects of this chronic forced use of the nondominant hand remain largely unknown. Yet, these effects may shed light on the potential to compensate for degradation or loss of dominant hand function, as well as the mechanisms that support motor learning under conditions of very long-term training. We used a novel precision drawing task and fMRI to investigate 8 adult human amputees with chronic (mean 33 years) unilateral dominant (right) hand absence, and right-handed matched controls (8 for fMRI, 19 for behavior). Amputees' precision drawing performances with their left hands reached levels of smoothness (associated with left hemisphere control), acceleration time (associated with right hemisphere control), and speed equivalent to controls' right hands, whereas accuracy maintained a level comparable with controls' left hands. This compensation is supported by an experience-dependent shift from heavy reliance on the dorsodorsal parietofrontal pathway (feedback control) to the ventrodorsal pathway and prefrontal regions involved in the cognitive control of goal-directed actions. Relative to controls, amputees also showed increased activity within the former cortical sensorimotor hand territory in the left (ipsilateral) hemisphere. These data demonstrate that, with chronic and exclusive forced use, the speed and quality of nondominant hand precision endpoint control in drawing can achieve levels nearly comparable with the dominant hand.

Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off.

PubMed

Weinert-Aplin, R A; Howard, D; Twiste, M; Jarvis, H L; Bennett, A N; Baker, R J

2017-01-01

Reduced capacity and increased metabolic cost of walking occurs in amputees, despite advances in prosthetic componentry. Joint powers can quantify deficiencies in prosthetic gait, but do not reveal how energy is exchanged between limb segments. This study aimed to quantify these energy exchanges during amputee walking. Optical motion and forceplate data collected during walking at a self-selected speed for cohorts of 10 controls, 10 unilateral trans-tibial, 10 unilateral trans-femoral and 10 bilateral trans-femoral amputees were used to determine the energy exchanges between lower limb segments. At push-off, consistent thigh and shank segment powers were observed between amputee groups (1.12W/kg vs. 1.05W/kg for intact limbs and 0.97W/kg vs. 0.99W/kg for prosthetic limbs), and reduced prosthetic ankle power, particularly in trans-femoral amputees (3.12W/kg vs. 0.87W/kg). Proximally-directed energy exchange was observed in the intact limbs of amputees and controls, while prosthetic limbs displayed distally-directed energy exchanges at the knee and hip. This study used energy flow analysis to show a reversal in the direction in which energy is exchanged between prosthetic limb segments at push-off. This reversal was required to provide sufficient energy to propel the limb segments and is likely a direct result of the lack of push-off power at the prosthetic ankle, particularly in trans-femoral amputees, and leads to their increased metabolic cost of walking. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees

NASA Astrophysics Data System (ADS)

Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

2017-08-01

This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction.

[Larynx reinnervation by the main branch of ansa cervicalis use in the thyroid surgery in cases of unilateral vocal fold paralysis].

PubMed

Palamarchuk, V A

2013-08-01

The effectiveness of laryngeal reinnervation by anza cervicalis abduction in the treatment of unilateral vocal fold paralysis in thyroid surgery was study. The prospectively examined 11 patients with abduction paralysis of the larynx, which were treated by ipsilateral anastomosis of anza cervicalis main branch to the distal stump of the recurrent laryngeal nerve were performed. The survey was conducted on the pre- and postoperative stages and included videolaryngoscopy, acoustic analysis, and patient self-assessment of voice. Average follow-up was (2.98 +/- 1.04) years. The use of videolaryngoscopy showed significant improvement of the spatial positioning of the vocal folds in the postoperative period and acoustical parameters. Laryngeal reinnervation by anza cervicalis is an effective treatment for laryngeal paralysis related to operations on the thyroid gland and laryngeal function can be improve to almost normal of the spoken voice parameters and the basic functions of the larynx.

Laryngeal Reinnervation Using Ansa Cervicalis for Thyroid Surgery-Related Unilateral Vocal Fold Paralysis: A Long-Term Outcome Analysis of 237 Cases

PubMed Central

Li, Ding; Li, Meng; Xia, Siwen; Zheng, Hongliang

2011-01-01

Objective To evaluate the long-term efficacy of delayed laryngeal reinnervation using the main branch of the ansa cervicalis in treatment of unilateral vocal fold paralysis (UVFP) caused by thyroid surgery. Summary of Background Data UVFP remains a serious complication of thyroid surgery. Up to now, a completely satisfactory surgical treatment of UVFP has been elusive. Methods From Jan. 1996 to Jan. 2008, a total of 237 UVFP patients who underwent ansa cervicalis main branch-to-recurrent laryngeal nerve (RLN) anastomosis were enrolled as UVFP group; another 237 age- and gender-matched normal subjects served as control group. Videostroboscopy, vocal function assessment (acoustic analysis, perceptual evaluation and maximum phonation time), and electromyography were performed preoperatively and postoperatively. The mean follow-up period was 5.2±2.7 years, ranging from 2 to 12 years. Results Analysis of videostroboscopic findings indicated that the glottic closure, vocal fold edge, vocal fold position, phase symmetry and regularity were significantly improved in the UVFP group (P<0.001, postoperative vs. preoperative). The postoperative parameters of vocal function were also significantly improved in the UVFP group (P<0.001) and showed no statistical differences compared to the control group (P>0.05, respectively). Postoperative laryngeal electromyography confirmed successful reinnervation of laryngeal muscle. Conclusions Delayed laryngeal reinnervation with the main branch of ansa cervicalis is a feasible and effective approach for treatment of thyroid surgery-related UVFP; it can restore the physiological laryngeal phonatory function to the normal or a nearly normal voice quality. PMID:21559458

Bioelectric analyses of an osseointegrated intelligent implant design system for amputees.

PubMed

Isaacson, Brad M; Stinstra, Jeroen G; MacLeod, Rob S; Webster, Joseph B; Beck, James P; Bloebaum, Roy D

2009-07-15

The projected number of American amputees is expected to rise to 3.6 million by 2050. Many of these individuals depend on artificial limbs to perform routine activities, but prosthetic suspensions using traditional socket technology can prove to be cumbersome and uncomfortable for a person with limb loss. Moreover, for those with high proximal amputations, limited residual limb length may prevent exoprosthesis attachment all together. Osseointegrated implant technology is a novel operative procedure which allows firm skeletal attachment between the host bone and an implant. Preliminary results in European amputees with osseointegrated implants have shown improved clinical outcomes by allowing direct transfer of loads to the bone-implant interface. Despite the apparent advantages of osseointegration over socket technology, the current rehabilitation procedures require long periods of restrictive load bearing prior which may be reduced with expedited skeletal attachment via electrical stimulation. The goal of the osseointegrated intelligent implant design (OIID) system is to make the implant part of an electrical system to accelerate skeletal attachment and help prevent periprosthetic infection. To determine optimal electrode size and placement, we initiated proof of concept with computational modeling of the electric fields and current densities that arise during electrical stimulation of amputee residual limbs. In order to provide insure patient safety, subjects with retrospective computed tomography scans were selected and three dimensional reconstructions were created using customized software programs to ensure anatomical accuracy (Seg3D and SCIRun) in an IRB and HIPAA approved study. These software packages supported the development of patient specific models and allowed for interactive manipulation of electrode position and size. Preliminary results indicate that electric fields and current densities can be generated at the implant interface to achieve the

A Bioimpedance Analysis Platform for Amputee Residual Limb Assessment.

PubMed

Sanders, Joan E; Moehring, Mark A; Rothlisberger, Travis M; Phillips, Reid H; Hartley, Tyler; Dietrich, Colin R; Redd, Christian B; Gardner, David W; Cagle, John C

2016-08-01

The objective of this research was to develop a bioimpedance platform for monitoring fluid volume in residual limbs of people with trans-tibial limb loss using prostheses. A customized multifrequency current stimulus profile was sent to thin flat electrodes positioned on the thigh and distal residual limb. The applied current signal and sensed voltage signals from four pairs of electrodes located on the anterior and posterior surfaces were demodulated into resistive and reactive components. An established electrical model (Cole) and segmental limb geometry model were used to convert results to extracellular and intracellular fluid volumes. Bench tests and testing on amputee participants were conducted to optimize the stimulus profile and electrode design and layout. The proximal current injection electrode needed to be at least 25 cm from the proximal voltage sensing electrode. A thin layer of hydrogel needed to be present during testing to ensure good electrical coupling. Using a burst duration of 2.0 ms, intermission interval of 100 μs, and sampling delay of 10 μs at each of 24 frequencies except 5 kHz, which required a 200-μs sampling delay, the system achieved a sampling rate of 19.7 Hz. The designed bioimpedance platform allowed system settings and electrode layouts and positions to be optimized for amputee limb fluid volume measurement. The system will be useful toward identifying and ranking prosthetic design features and participant characteristics that impact residual limb fluid volume.

The evolution of functional hand replacement: From iron prostheses to hand transplantation

PubMed Central

Zuo, Kevin J; Olson, Jaret L

2014-01-01

The hand is an integral component of the human body, with an incredible spectrum of functionality. In addition to possessing gross and fine motor capabilities essential for physical survival, the hand is fundamental to social conventions, enabling greeting, grooming, artistic expression and syntactical communication. The loss of one or both hands is, thus, a devastating experience, requiring significant psychological support and physical rehabilitation. The majority of hand amputations occur in working-age males, most commonly as a result of work-related trauma or as casualties sustained during combat. For millennia, humans have used state-of-the-art technology to design clever devices to facilitate the reintegration of hand amputees into society. The present article provides a historical overview of the progress in replacing a missing hand, from early iron hands intended primarily for use in battle, to today’s standard body-powered and myoelectric prostheses, to revolutionary advancements in the restoration of sensorimotor control with targeted reinnervation and hand transplantation. PMID:25152647

[The bionic hand].

PubMed

Surke, Carsten; Ducommun Dit Boudry, Pascal; Vögelin, Esther

2015-08-01

The loss of the upper extremity implicates a grave insult in the life of the involved person. To compensate for the loss of function different powered prosthetic devices are available. Ever since their first development 70 years ago numerous improvements in terms of size, weight and wearing comfort have been developed, but issues regarding the control of upper extremity prostheses remain. Slow grasping speed, limited grip positions and especially failure to provide a sensory feedback limit the acceptance in patients. Recent developments are aimed to allow a more intuitive control of the prosthetic device and to provide a sensory feedback to the amputee. Targeted reinnervation reassignes existing muscles to different peripheral nerves thereby enabling them to fulfill alternate functions. Implanting electrodes into muscle bellies of the forearm allows a more accurate control of the prosthesis. Promising results are being achieved by implanting nerve electrodes by establishing bilateral communication between patient and prosthesis. The following review summarizes the current developments of bionic prostheses in the upper extremity.

Epidemiologic data of trauma-related lower limb amputees: A single center 10-year experience.

PubMed

Yaşar, Evren; Tok, Fatih; Kesikburun, Serdar; Ada, A Mustafa; Kelle, Bayram; Göktepe, A Salim; Yazıcıoğlu, Kamil; Tan, A Kenan

2017-02-01

The aim of this study is three fold: 1) to introduce epidemiologic data of patients with trauma-related amputations as a 10-year experience of a rehabitation center; 2) to determine comorbidities and secondary conditions of lower limb loss; 3) to determine the rehospitalization reasons for lower limb amputee patients. This retrospective study was conducted in a tertiary rehabilitation center in Turkey. Clinical and demographic data of amputees including sex, age, employment status, time since amputation, time after amputation to first hospitalization, length of hospitalization, how many times the patient was hospitalized, reason for hospitalization, stump complications, comorbid conditions, amputation level and K classifacation were documented. Three hundred ninetynine patients with a mean age of 23,48±6,04 (4-74) years were included in this study. Mean duration after amputation was 119,71±68,86months. Patients were 3,43±2,53 times hospitalized. Landmine explosion was the most common etiology of amputation with 370 patients (92.7%). Below knee amputation was the most common amputation level with 230 (50,77%) amputations. 399 patients were hospitalized 1369 times and the most common hospitalization reason were stump complications (356 times, 26,00%). Spur formation (202 times) was the most common stump complications. Pyscologic disorders were the most common comorbidity with 68 patient (37,56%). Patients with traumatic limb amputations are likely to experience several complications and comorbidities. Prevention of secondary conditions affecting those living with the loss of a limb is an important part of amputee rehabilitation and may prevent rehospitalization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Standing on slopes - how current microprocessor-controlled prosthetic feet support transtibial and transfemoral amputees in an everyday task.

PubMed

Ernst, Michael; Altenburg, Björn; Bellmann, Malte; Schmalz, Thomas

2017-11-16

Conventional prosthetic feet like energy storage and return feet provide only a limited range of ankle motion compared to human ones. In order to overcome the poor rotational adaptability, prosthetic manufacturers developed different prosthetic feet with an additional rotational joint and implemented active control in different states. It was the aim of the study to investigate to what extent these commercially available microprocessor-controlled prosthetic feet support a natural posture while standing on inclines and which concept is most beneficial for lower limb amputees. Four unilateral transtibial and four unilateral transfemoral amputees participated in the study. Each of the subjects wore five different microprocessor-controlled prosthetic feet in addition to their everyday feet. The subjects were asked to stand on slopes of different inclinations (level ground, upward slope of 10°, and downward slope of -10°). Vertical ground reaction forces, joint torques and joint angles in the sagittal plane were measured for both legs separately for the different situations and compared to a non-amputee reference group. Differences in the biomechanical parameters were observed between the different prosthetic feet and compared to the reference group for the investigated situations. They were most prominent while standing on a downward slope. For example, on the prosthetic side, the vertical ground reaction force is reduced by about 20%, and the torque about the knee acts to flex the joint for feet that are not capable of a full adaptation to the downward slope. In contrast, fully adaptable feet with an auto-adaptive dorsiflexion stop show no changes in vertical ground reaction forces and knee extending torques. A prosthetic foot that provides both, an auto-adaptive dorsiflexion stop and a sufficient range of motion for fully adapting to inclinations appears to be the key element in the prosthetic fitting for standing on inclinations in lower limb amputees. In such

Artificial redirection of sensation from prosthetic fingers to the phantom hand map on transradial amputees: vibrotactile versus mechanotactile sensory feedback.

PubMed

Antfolk, Christian; D'Alonzo, Marco; Controzzi, Marco; Lundborg, Göran; Rosén, Birgitta; Sebelius, Fredrik; Cipriani, Christian

2013-01-01

This work assesses the ability of transradial amputees to discriminate multi-site tactile stimuli in sensory discrimination tasks. It compares different sensory feedback modalities using an artificial hand prosthesis in: 1) a modality matched paradigm where pressure recorded on the five fingertips of the hand was fed back as pressure stimulation on five target points on the residual limb; and 2) a modality mismatched paradigm where the pressures were transformed into mechanical vibrations and fed back. Eight transradial amputees took part in the study and were divided in two groups based on the integrity of their phantom map; group A had a complete phantom map on the residual limb whereas group B had an incomplete or nonexisting map. The ability in localizing stimuli was compared with that of 10 healthy subjects using the vibration feedback and 11 healthy subjects using the pressure feedback (in a previous study), on their forearms, in similar experiments. Results demonstrate that pressure stimulation surpassed vibrotactile stimulation in multi-site sensory feedback discrimination. Furthermore, we demonstrate that subjects with a detailed phantom map had the best discrimination performance and even surpassed healthy participants for both feedback paradigms whereas group B had the worst performance overall. Finally, we show that placement of feedback devices on a complete phantom map improves multi-site sensory feedback discrimination, independently of the feedback modality.

Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees.

PubMed

Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

2017-08-01

This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

The effect of segmental weight of prosthesis on hemodynamic responses and energy expenditure of lower extremity amputees

PubMed Central

Mutlu, Akmer; Kharooty, Mohammad Dawood; Yakut, Yavuz

2017-01-01

[Purpose] The aim of this study was to investigate the effect of segmental weight of the prosthesis on hemodynamic responses and energy expenditure in lower extremity amputees. [Subjects and Methods] Thirteen patients with a mean age of 44 ± 15.84 years and with unilateral transtibial, transfemoral and Syme’s amputation were included to the study. The difference between the lightest and the heaviest prosthesis, 250 g used as the weight. All the patients completed the measurements first without weight and then with 250 g weight on the ankle joint. The blood pressure and heart rate of the patients were recorded before and after Six Minute Walk Test (6MWT) and 10 stairs up & down stairs test. Physiological Cost Index was used to calculate the energy expenditure. [Results] Heart rate and energy expenditure increased significantly when without weight and with weight results compared. [Conclusion] We conclude that the segmental weight of the prosthetic limb has a significant effect on the heart rate and energy expenditure but has no effect on the systolic and diastolic blood pressure of lower limb amputees. In order to generalize our results to lower limb amputees, more patients need to be included in future studies. PMID:28533599

[Comparative study of the volume difference vs. healthy limb, morphological and population description in transfemoral amputees].

PubMed

Mendoza-Cruz, Felipe; Rodríguez-Reyes, Gerardo; Galván Duque-Gastélum, Carlos; Alvarez-Camacho, Michelín

2014-07-01

Knowledge of the general characteristics and physical condition that keeps the transfemoral amputation stump to select and adapt appropriate type of prosthesis to restore a walking pattern amputee patient acceptable and useful design parameters set to propose new prosthetic systems. In this paper, the degree of difference between the volumes of the limb stump and healthy as well as morphological features occurred more frequently in the stumps of transfemoral amputees who were treated at the Laboratory of Orthotics and Prosthetics (LOP), Instituto Nacional de Rehabilitación (INR) in 2008. It captured all patients with unilateral transfemoral amputation left and right, over 18 years old, both sexes, use of hearing candidates were evaluated clinically and took three measurements of the circumferences at different wavelengths and the limb stump healthy, were calculated volumes of both sides using the mathematical model of the truncated cone and analyzed in three groups according to the level of amputation (proximal, middle and distal third). We obtained 49 patients, 39 men and 10 women, the difference stump volume compared to healthy limb volume per group were: 44.9% proximal third, middle third and distal 26.5%, 21.1%, the frequency of diagnostic data showed a stump right transfemoral amputees, due to metabolic, without use of prostheses, the most common morphological features indicate that the stump has a conical shape and size distal third, whose tissue is semi-flaccid consistency, the scar is not adhered to deep planes and shows a negative tinel, the mattress soft tissue is 2.15 ± 1.3 cm and physically presents a force level 4 in the clinical rating scale Daniels. The data are consistent with other studies comparing the percentage of the volume change with the percentages of reduced diameters transfemoral stump muscle, likewise agrees most amputees incidence of diabetes mellitus with other studies, cataloging it eat first cause amputation. The general description

Two-dimensional myoelectric control of a robotic arm for upper limb amputees

NASA Astrophysics Data System (ADS)

López Celani, Natalia M.; Soria, Carlos M.; Orosco, Eugenio C.; di Sciascio, Fernando A.; Valentinuzzi, Max E.

2007-11-01

Rehabilitation engineering and medicine have become integral and significant parts of health care services, particularly and unfortunately in the last three or four decades, because of wars, terrorism and large number of car accidents. Amputees show a high rate of rejection to wear prosthetic devices, often because of lack of an adequate period of adaptation. A robotic arm may appear as a good preliminary stage. To test the hypothesis, myoelectric signals from two upper limb amputees and from four normal volunteers were fed, via adequate electronic conditioning and using MATLAB, to an industrial robotic arm. Proportional strength control was used for two degrees of freedom (x-y plane) by means of eight signal features of control (four traditional statistics plus energy, integral of the absolute value, Willison's amplitude, waveform length and envelope) for comparison purposes, and selecting the best of them as final reference. Patients easily accepted the system and learned in short time how to operate it. Results were encouraging so that valuable training, before prosthesis is implanted, appears as good feedback; besides, these patients can be hired as specialized operators in semi-automatized industry.

Fractal and twin SVM-based handgrip recognition for healthy subjects and trans-radial amputees using myoelectric signal.

PubMed

Arjunan, Sridhar Poosapadi; Kumar, Dinesh Kant; Jayadeva J

2016-02-01

Identifying functional handgrip patterns using surface electromygram (sEMG) signal recorded from amputee residual muscle is required for controlling the myoelectric prosthetic hand. In this study, we have computed the signal fractal dimension (FD) and maximum fractal length (MFL) during different grip patterns performed by healthy and transradial amputee subjects. The FD and MFL of the sEMG, referred to as the fractal features, were classified using twin support vector machines (TSVM) to recognize the handgrips. TSVM requires fewer support vectors, is suitable for data sets with unbalanced distributions, and can simultaneously be trained for improving both sensitivity and specificity. When compared with other methods, this technique resulted in improved grip recognition accuracy, sensitivity, and specificity, and this improvement was significant (κ=0.91).

Variables Affecting the Amputees' Reactions Artificial Limbs in the Kingdom of Jordan

ERIC Educational Resources Information Center

Al-Adwan, Mezyed; Najjar, Yahya; Hdaib, Maha; Al-Khateeb, Monadel

2017-01-01

Amputee reaction to artificial limb is an important issue faces amputated individuals and the team who delivers services to these individuals. Although some individuals using artificial limb accept it, some others do not. There are several factors that may make it difficult to accept the artificial limb for a long time. The aim of this study is to…

Virtual Constraint Control of a Powered Prosthetic Leg: From Simulation to Experiments with Transfemoral Amputees.

PubMed

Gregg, Robert D; Lenzi, Tommaso; Hargrove, Levi J; Sensinger, Jonathon W

2014-12-01

Recent powered (or robotic) prosthetic legs independently control different joints and time periods of the gait cycle, resulting in control parameters and switching rules that can be difficult to tune by clinicians. This challenge might be addressed by a unifying control model used by recent bipedal robots, in which virtual constraints define joint patterns as functions of a monotonic variable that continuously represents the gait cycle phase. In the first application of virtual constraints to amputee locomotion, this paper derives exact and approximate control laws for a partial feedback linearization to enforce virtual constraints on a prosthetic leg. We then encode a human-inspired invariance property called effective shape into virtual constraints for the stance period. After simulating the robustness of the partial feedback linearization to clinically meaningful conditions, we experimentally implement this control strategy on a powered transfemoral leg. We report the results of three amputee subjects walking overground and at variable cadences on a treadmill, demonstrating the clinical viability of this novel control approach.

Return-to-duty rates among US military combat-related amputees in the global war on terror: job description matters.

PubMed

Belisle, Jeffery G; Wenke, Joseph C; Krueger, Chad A

2013-08-01

The purpose of this study was to identify the differences seen between military occupation services (MOS) in terms of amputation patterns, subsequent disabling conditions, and their ability to return to duty. A retrospective study of major extremity amputations sustained by US service members between October 1, 2001, and July 30, 2011, was performed. Data obtained from the amputation database, Joint Trauma Theater Database, and the Physical Evaluation Board Liaison Office included demographics, amputation location(s), Injury Severity Scores (ISSs), disabling conditions, disability ratings, and disposition status. There were 1,221 major extremity amputees identified during the specified time frame, of which 899 had data regarding disabling conditions, ratings, and disposition. All service branches were represented. Personnel from the US Army (USA) Infantry were significantly (p < 0.0001) more likely to sustain an amputation than other MOS. The USA Infantry, the US Marine Corps Infantry and the USA Armor represented the top three specialties and accounted for more than 57% of all amputees. Approximately 89% of all service members did not return to duty, and the mean combined for all amputees was 76. USA Special Forces (USA SF) operators were significantly more likely to return to duty (p = 0.0022) and be found fit for duty (p = 0.0015) than all other MOS despite having a mean ISS (20) that was no different from those of other service members. No USA SF personnel were found to have posttraumatic stress disorder as a disabling condition. All amputees, regardless of MOS, are not likely to return to active duty and especially unlikely to be found fit for duty, except for members of the USA SF. The reason(s) for the increased return to duty for USA SF personnel remains unknown but a lack of posttraumatic stress disorder may be a contributing factor.

Body image and self-esteem in lower-limb amputees.

PubMed

Holzer, Lukas A; Sevelda, Florian; Fraberger, Georg; Bluder, Olivia; Kickinger, Wolfgang; Holzer, Gerold

2014-01-01

Limb amputation is often an inevitable procedure in the advanced condition of various diseases and poses a dramatic impact on a patient's life. The aim of the present study is to analyze the impact of lower-limb amputations on aesthetic factors such as body image and self-esteem as well as quality of life (QoL). 298 patients (149 uni- or bilateral lower-limb amputees and 149 controls) were included in this cross-sectional study in three centers. Demographic data was collected and patients received a 118-item questionnaire including the Multidimensional Body-Self Relations Questionnaire (MBSRQ), the Rosenberg Self-esteem (RSE) scale and the SF-36 Health Survey (QoL). ANOVA and student's t-test were used for statistical analysis. Unilateral lower-limb amputees showed a significant lower MBSRQ score of 3.07±0.54 compared with 3.41±0.34 in controls (p<0.001) and a lower score in the RSE compared to controls (21.63±4.72 vs. 21.46±5.86). However, differences were not statistically significant (p = 0.36). Patients with phantom pain sensation had a significantly reduced RSE (p = 0.01). The SF-36 health survey was significantly lower in patients with lower-limb amputation compared to controls (42.17±14.47 vs. 64.05±12.39) (p<0.001). This study showed that lower-limb amputations significantly influence patients' body image and QoL. Self-esteem seems to be an independent aspect, which is not affected by lower-limb amputation. However, self-esteem is influenced significantly by phantom pain sensation.

Feasibility testing of smart tablet questionnaires compared to paper questionnaires in an amputee rehabilitation clinic.

PubMed

Payne, Michael; Janzen, Shannon; Earl, Eric; Deathe, Barry; Viana, Ricardo

2017-08-01

Capturing the variability that exists among patients attending an amputee clinic using standardized paper-based questionnaires is time-consuming and may not be practical for routine clinical use. Electronic questionnaires are a potential solution; however, the benefits are dependent on the feasibility and acceptance of this mode of data collection among patients. To determine the feasibility and patient preference/comfort in using a tablet-based questionnaire for data collection in an outpatient amputee rehabilitation clinic compared to a traditional paper-based questionnaire. Observational study. In all, 48 patients with major extremity amputations completed both tablet and paper questionnaires related to their amputation and prosthetic use. Both trials were timed; patients then completed a semi-structured questionnaire about their experience. In all, 20.5% of patients needed hands-on assistance completing the paper questionnaire compared to 20.8% for the tablet. The majority of participants (52.1%) indicated a preference for the tablet questionnaire; 64.6% of patients felt the tablet collected a more complete and accurate representation of their status and needs. In all, 70.8% of participants described themselves as comfortable using the tablet. Despite comorbidities, patients with amputations demonstrated excellent acceptance of the electronic tablet-based questionnaire. Tablet questionnaires have significant potential advantages over paper questionnaires and should be further explored. Clinical relevance A custom electronic questionnaire was found to be beneficial for routine clinic use and was well received by patients in an amputee rehabilitation clinic. Development of such questionnaires can provide an efficient mechanism to collect meaningful data that can be used for individual patient care and program quality improvement initiatives.

Selectivity in the Reinnervation of the Lateral Gastrocnemius Muscle after Nerve Repair with Ethyl Cyanoacrylate in the Rat

PubMed Central

Landegren, Thomas; Risling, Mårten; Hammarberg, Henrik; Persson, Jonas K. E.

2011-01-01

There is a need for complementary surgical techniques that enable rapid and reliable primary repair of transected nerves. Previous studies after peripheral nerve transection and repair with synthetic adhesives have demonstrated regeneration to an extent comparable to that of conventional techniques. The aim of this study was to compare two different repair techniques on the selectivity of muscle reinnervation after repair and completed regeneration. We used the cholera toxin B technique of retrograde axonal tracing to evaluate the morphology, the number, and the three-dimensional location of α-motoneurons innervating the lateral gastrocnemius muscle and compared the results after repair with either ethyl cyanoacrylate (ECA) or epineural sutures of the transected parent sciatic nerve. In addition, we recorded the wet weight of the muscle. Six months after transection and repair of the sciatic nerve, the redistribution of the motoneuron pool was markedly disorganized, the motoneurons had apparently increased in number, and they were scattered throughout a larger volume of the spinal cord gray matter with a decrease in the synaptic coverage compared to controls. A reduction in muscle weight was observed as well. No difference in morphometric variables or muscle weight between the two repair methods could be detected. We conclude that the selectivity of motor reinnervation following sciatic nerve transection and subsequent repair with ECA is comparable to that following conventional micro suturing. PMID:21577248

Laryngeal reinnervation featuring refined nerve-muscle pedicle implantation evaluated via electromyography and use of coronal images.

PubMed

Sanuki, Tetsuji; Yumoto, Eiji; Nishimoto, Kohei; Kodama, Narihiro; Kodama, Haruka; Minoda, Ryosei

2015-04-01

To evaluate the long-term efficacy of laryngeal reinnervation via refined nerve-muscle pedicle (NMP) flap implantation combined with arytenoid adduction to treat unilateral vocal fold paralysis (UVFP), employing laryngeal electromyography (LEMG), coronal imaging, and phonatory function assessment. Case series with chart review. University hospital. We retrospectively reviewed 12 UVFP patients who underwent refined NMP implantation with arytenoid adduction. Videostroboscopy, phonatory functional analysis, LEMG, and coronal imaging were performed before and 2 years after surgery. In LEMG analysis, a 4-point scale was employed to grade motor unit (MU) recruitment: 4+ reflected no recruitment, 3+ greatly decreased recruitment, 2+ moderately decreased recruitment, and 1+ mildly decreased activity, associated with less than the full interference pattern. Coronal images were assessed in terms of differences in thickness and the vertical positions of the vocal folds. Phonatory function improved significantly after operation in all patients. In terms of LEMG findings, the preoperative MU recruitment scores were 1+ in no patients, 2+ in 4 patients, 3+ in 1 patient, and 4+ in 7 patients. Postoperative MU recruitment results were 1+ in 6 patients, 2+ in 5 patients, 3+ in 1 patient, and 4+ in no patients. Thinning of the affected fold during phonation was evident preoperatively in 9 of 10 patients. The affected and healthy folds were equal in volume in 4 of 9 patients postoperatively. The LEMG findings and coronal imaging suggest that NMP implantation may have enabled successful reinnervation of the laryngeal muscles of UVFP patients. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Assessment of transfemoral amputees using a passive microprocessor-controlled knee versus an active powered microprocessor-controlled knee for level walking.

PubMed

Creylman, Veerle; Knippels, Ingrid; Janssen, Paul; Biesbrouck, Evelyne; Lechler, Knut; Peeraer, Louis

2016-12-19

In transfemoral (TF) amputees, the forward propulsion of the prosthetic leg in swing has to be mainly carried out by hip muscles. With hip strength being the strongest predictor to ambulation ability, an active powered knee joint could have a positive influence, lowering hip loading and contributing to ambulation mobility. To assess this, gait of four TF amputees was measured for level walking, first while using a passive microprocessor-controlled prosthetic knee (P-MPK), subsequently while using an active powered microprocessor-controlled prosthetic knee (A-MPK). Furthermore, to assess long-term effects of the use of an A-MPK, a 4-weeks follow-up case study was performed. The kinetics and kinematics of the gait of four TF amputees were assessed while walking with subsequently the P-MPK and the A-MPK. For one amputee, a follow-up study was performed: he used the A-MPK for 4 weeks, his gait was measured weekly. The range of motion of the knee was higher on both the prosthetic and the sound leg in the A-MPK compared to the P-MPK. Maximum hip torque (HT) during early stance increased for the prosthetic leg and decreased for the sound leg with the A-MPK compared to the P-MPK. During late stance, the maximum HT decreased for the prosthetic leg. The difference between prosthetic and sound leg for HT disappeared when using the A-MPK. Also, an increase in stance phase duration was observed. The follow-up study showed an increase in confidence with the A-MPK over time. Results suggested that, partially due to an induced knee flexion during stance, HT can be diminished when walking with the A-MPK compared to the P-MPK. The single case follow-up study showed positive trends indicating that an adaptation time is beneficial for the A-MPK.

Effects of ladder parameters on asymmetric patterns of force exertion during below-knee amputees climbing ladders.

PubMed

Li, Weidong; Li, Shiqi; Fu, Yan; Chen, Jacon

2017-03-01

Different from walking, ladder climbing requires four-limb coordination and more energy exertion for below-knee amputees (BKAs). We hypothesized that functional deficiency of a disabled limb shall be compensated by the other three intact limbs, showing an asymmetry pattern among limbs. Hand and foot forces of six below-knee amputees and six able-bodied people were collected. Hand, foot and hand/foot sum force variances between groups (non-BKA, intact side and prosthetic side) were carefully examined. Our hypothesis was validated that there is asymmetry between prosthetic and intact side. Results further showed that the ipsilateral hand of the prosthetic leg is stronger than the hand on the intact side, compensating weakness of the prosthetic leg. Effects of ladder rung separations and ladder slant on asymmetric force distribution of BKAs were evaluated, indicating that rung separation has a more significant interactive effect on hand/foot force of BKAs than ladder slant.

Virtual Constraint Control of a Powered Prosthetic Leg: From Simulation to Experiments with Transfemoral Amputees

PubMed Central

Lenzi, Tommaso; Hargrove, Levi J.; Sensinger, Jonathon W.

2014-01-01

Recent powered (or robotic) prosthetic legs independently control different joints and time periods of the gait cycle, resulting in control parameters and switching rules that can be difficult to tune by clinicians. This challenge might be addressed by a unifying control model used by recent bipedal robots, in which virtual constraints define joint patterns as functions of a monotonic variable that continuously represents the gait cycle phase. In the first application of virtual constraints to amputee locomotion, this paper derives exact and approximate control laws for a partial feedback linearization to enforce virtual constraints on a prosthetic leg. We then encode a human-inspired invariance property called effective shape into virtual constraints for the stance period. After simulating the robustness of the partial feedback linearization to clinically meaningful conditions, we experimentally implement this control strategy on a powered transfemoral leg. We report the results of three amputee subjects walking overground and at variable cadences on a treadmill, demonstrating the clinical viability of this novel control approach. PMID:25558185

Cross-cultural validation of the Prosthesis Evaluation Questionnaire in vascular amputees fitted with prostheses in Spain.

PubMed

Benavent, Jose Vicente; Igual, Celedonia; Mora, Enrique; Antonio, Rosa; Tenias, Jose Maria

2016-12-01

The lack of specific prosthetic-related outcome instruments for Spanish amputees must be addressed. To elaborate a culturally equivalent version of the Prosthesis Evaluation Questionnaire in the Spanish language. Cross-cultural questionnaire validation. Two-step process for cultural adaptation: forward and backward translations of English original and Spanish translated versions; assessment of both construct and criterion validity and reliability in a group of vascular amputees. A total of 61 patients were recruited, 44 men (72.1%) and 17 women (27.9%), with a median age of 71.1 years (standard deviation: 7.7 years; range: 51-87 years). In the Prosthesis Evaluation Questionnaire-Spanish, the lowest scores were for gait and frustration, and the highest scores were for noise and stump health. Internal consistency of the questionnaire was acceptable (>0.70) for four of the scales used in the Prosthesis Evaluation Questionnaire but poor (<0.50) for the scales relating to appearance and stump health. Correlations with the quality-of-life levels as measured by the Short Form-36 were positive and mostly significant. Prosthesis Evaluation Questionnaire-Spanish could assess the quality of life in patients who have undergone vascular amputations and then been fitted with a prosthetic limb. The questionnaire shows adequate criteria validity when compared with other instruments for measuring quality of life. The Prosthesis Evaluation Questionnaire-Spanish could be a valid and reliable instrument for assessing adaptation to prostheses in vascular amputees. The questionnaire adds information relevant to the patient and the physician and may identify cases with poor expected adaptation to the prosthesis. © The International Society for Prosthetics and Orthotics 2015.

Safety and function of a prototype microprocessor-controlled knee prosthesis for low active transfemoral amputees switching from a mechanic knee prosthesis: a pilot study.

PubMed

Hasenoehrl, Timothy; Schmalz, Thomas; Windhager, Reinhard; Domayer, Stephan; Dana, Sara; Ambrozy, Clemens; Palma, Stefano; Crevenna, Richard

2018-02-01

Aim of this pilot study was to assess safety and functioning of a microprocessor-controlled knee prosthesis (MPK) after a short familiarization time and no structured physical therapy. Five elderly, low-active transfemoral amputees who were fitted with a standard non-microprocessor controlled knee prosthesis (NMPK) performed a baseline measurement consisting of a 3 D gait analysis, functional tests and questionnaires. The first follow-up consisted of the same test procedure and was performed with the MPK after 4 to 6 weeks of familiarization. After being refitted to their standard NMPK again, the subjects undertook the second follow-up which consisted of solely questionnaires 4 weeks later. Questionnaires and functional tests showed an increase in the perception of safety. Moreover, gait analysis revealed more physiologic knee and hip extension/flexion patterns when using the MPK. Our results showed that although the Genium with Cenior-Leg ruleset-MPK (GCL-MPK) might help to improve several safety-related outcomes as well as gait biomechanics the functional potential of the GCL-MPK may have been limited without specific training and a sufficient acclimation period. Implications for Rehabilitation Elderly transfemoral amputees are often limited in their activity by safety issues as well as insufficient functioning regarding the non microprocessor-controlled knee prostheses (NMPK), thing that could be eliminated with the use of suitable microprocessor-controlled prostheses (MPK). The safety and functioning of a prototype MPK (GCL-MPK) specifically designed for the needs of older and low-active transfemoral amputees was assessed in this pilot study. The GCL-MPK showed indicators of increased safety and more natural walking patterns in older and low-active transfemoral amputees in comparison to the standard NMPK already after a short acclimatisation time and no structured physical therapy. Regarding functional performance it seems as if providing older and low

Sports Adaptations for Unilateral and Bilateral Upper-Limb Amputees: Archery/Badminton/Baseball/Softball/Bowling/Golf/Table Tennis.

ERIC Educational Resources Information Center

Cowart, Jim

1979-01-01

The booklet discusses sports adaptations for unilateral and bilateral upper limb amputees. Designs for adapted equipment are illustrated and information on adaptations are described for archery (including an archery release aid and a stationary bow holder); badminton (serving tray); baseball/softball (adaptations for catching, throwing, and…

The African disability scooter: efficiency testing in paediatric amputees in Malawi

PubMed Central

Beckles, Verona; McCahill, Jennifer L.; Stebbins, Julie; Mkandawire, Nyengo; Church, John C. T.; Lavy, Chris

2016-01-01

Abstract Purpose: The African Disability Scooter (ADS) was developed for lower limb amputees, to improve mobility and provide access to different terrains. The aim of this study was to test the efficiency of the ADS in Africa over different terrains. Method: Eight subjects with a mean age of 12 years participated. Energy expenditure and speed were calculated over different terrains using the ADS, a prosthetic limb, and crutches. Repeated testing was completed on different days to assess learning effect. Results: Speed was significantly faster with the ADS on a level surface compared to crutch walking. This difference was maintained when using the scooter on rough terrain. Oxygen cost was halved with the scooter on level ground compared to crutch walking. There were no significant differences in oxygen consumption or heart rate. There were significant differences in oxygen cost and speed between days using the scooter over level ground, suggesting the presence of a learning effect. Conclusions: This study demonstrates that the ADS is faster and more energy efficient than crutch walking in young individuals with amputations, and should be considered as an alternative to a prosthesis where this is not available. The presence of a learning effect suggests supervision and training is required when the scooter is first issued.Implications for RehabilitationThe African Disability Scooter:is faster than crutch walking in amputees;is more energy efficient than walking with crutches;supervised use is needed when learning to use the device;is a good alternative/adjunct for mobility. PMID:25316033

The benefits of using a vacuum-assisted socket system to improve balance and gait in elderly transtibial amputees.

PubMed

Samitier, C Beatriz; Guirao, Lluis; Costea, Maria; Camós, Josep M; Pleguezuelos, Eulogio

2016-02-01

Lower limb amputation leads to impaired balance, ambulation, and transfers. Proper fit of the prosthesis is a determining factor for successful ambulation. Vacuum-assisted socket systems extract air from the socket, which decreases pistoning and probability of soft-tissue injuries and increases proprioception and socket comfort. To investigate the effect of vacuum-assisted socket system on transtibial amputees' performance-based and perceived balance, transfers, and gait. Quasi-experimental before-and-after study. Subjects were initially assessed using their prosthesis with the regular socket and re-evaluated 4 weeks after fitting including the vacuum-assisted socket system. We evaluated the mobility grade using Medicare Functional Classification Level, Berg Balance Scale, Four Square Step Test, Timed Up and Go Test, the 6-Min Walk Test, the Locomotor Capabilities Index, Satisfaction with Prosthesis (SAT-PRO questionnaire), and Houghton Scale. A total of 16 unilateral transtibial dysvascular amputees, mean age 65.12 (standard deviation = 10.15) years. Using the vacuum-assisted socket system, the patients significantly improved in balance, gait, and transfers: scores of the Berg Balance Scale increased from 45.75 (standard deviation = 6.91) to 49.06 (standard deviation = 5.62) (p < 0.01), Four Square Step Test decreased from 18.18 (standard deviation = 3.84) s to 14.97 (3.9) s (p < 0.01), Timed Up and Go Test decreased from 14.3 (standard deviation = 3.29) s to 11.56 (2.46) s (p < 0.01). The distance walked in the 6-Min Walk Test increased from 288.53 (standard deviation = 59.57) m to 321.38 (standard deviation = 72.81) m (p < 0.01). Vacuum-assisted socket systems are useful for improving balance, gait, and transfers in over-50-year-old dysvascular transtibial amputees. This study gives more insight into the use of vacuum-assisted socket systems to improve elderly transtibial dysvascular amputees

User intent prediction with a scaled conjugate gradient trained artificial neural network for lower limb amputees using a powered prosthesis.

PubMed

Woodward, Richard B; Spanias, John A; Hargrove, Levi J

2016-08-01

Powered lower limb prostheses have the ability to provide greater mobility for amputee patients. Such prostheses often have pre-programmed modes which can allow activities such as climbing stairs and descending ramps, something which many amputees struggle with when using non-powered limbs. Previous literature has shown how pattern classification can allow seamless transitions between modes with a high accuracy and without any user interaction. Although accurate, training and testing each subject with their own dependent data is time consuming. By using subject independent datasets, whereby a unique subject is tested against a pooled dataset of other subjects, we believe subject training time can be reduced while still achieving an accurate classification. We present here an intent recognition system using an artificial neural network (ANN) with a scaled conjugate gradient learning algorithm to classify gait intention with user-dependent and independent datasets for six unilateral lower limb amputees. We compare these results against a linear discriminant analysis (LDA) classifier. The ANN was found to have significantly lower classification error (P<;0.05) than LDA with all user-dependent step-types, as well as transitional steps for user-independent datasets. Both types of classifiers are capable of making fast decisions; 1.29 and 2.83 ms for the LDA and ANN respectively. These results suggest that ANNs can provide suitable and accurate offline classification in prosthesis gait prediction.

Gait termination on a declined surface in trans-femoral amputees: Impact of using microprocessor-controlled limb system.

PubMed

Abdulhasan, Zahraa M; Scally, Andy J; Buckley, John G

2018-05-30

Walking down ramps is a demanding task for transfemoral-amputees and terminating gait on ramps is even more challenging because of the requirement to maintain a stable limb so that it can do the necessary negative mechanical work on the centre-of-mass in order to arrest (dissipate) forward/downward velocity. We determined how the use of a microprocessor-controlled limb system (simultaneous control over hydraulic resistances at ankle and knee) affected the negative mechanical work done by each limb when transfemoral-amputees terminated gait during ramp descent. Eight transfemoral-amputees completed planned gait terminations (stopping on prosthesis) on a 5-degree ramp from slow and customary walking speeds, with the limb's microprocessor active or inactive. When active the limb operated in its 'ramp-descent' mode and when inactive the knee and ankle devices functioned at constant default levels. Negative limb work, determined as the integral of the negative mechanical (external) limb power during the braking phase, was compared across speeds and microprocessor conditions. Negative work done by each limb increased with speed (p < 0.001), and on the prosthetic limb it was greater when the microprocessor was active compared to inactive (p = 0.004). There was no change in work done across microprocessor conditions on the intact limb (p = 0.35). Greater involvement of the prosthetic limb when the limb system was active indicates its ramp-descent mode effectively altered the hydraulic resistances at the ankle and knee. Findings highlight participants became more assured using their prosthetic limb to arrest centre-of-mass velocity. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effectiveness of a back school program in lowerlimb amputees: a randomized controlled study.

PubMed

Anaforoğlu, Bahar; Erbahçeci, Fatih; Aksekili, Mehmet Atıf Erol

2016-06-23

A few studies have been carried out in lower limb amputees (LLAs) and they examined the incidence of and reasons for low back pain. The aim of this study was to assess the effectiveness of a back school program in LLAs with mechanical low back pain (MLBP). Forty male unilateral transfemoral amputees with MLBP were randomly allocated into two groups. A back school program was applied to Group 1 over 2 weeks. A booklet for home use was given to each participant in Group 2. Pain was assessed using a visual analogue scale. Spinal flexibility measurements were obtained. For the assessment of back pain-related disability, the Oswestry Disability Index was used. Patients were assessed at baseline, at month 1, and at month 3. At the month 1 assessment, a reduction in pain intensity and disability, and increase in spinal flexibility measurements were detected in Group 1 only (P < 0.05). At the month 3 assessment, there were improvements in all measured parameters in both groups(P < 0.05). Group 1 had better results in all parameters compared with Group 2. The back school program, combined with an exercise program, decreased pain and disability and improved the spinal flexibility significantly in LLAs with MLBP.

Energy expenditure and activity of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.

PubMed

Kaufman, Kenton R; Levine, James A; Brey, Robert H; McCrady, Shelly K; Padgett, Denny J; Joyner, Michael J

2008-07-01

To quantify the energy efficiency of locomotion and free-living physical activity energy expenditure of transfemoral amputees using a mechanical and microprocessor-controlled prosthetic knee. Repeated-measures design to evaluate comparative functional outcomes. Exercise physiology laboratory and community free-living environment. Subjects (N=15; 12 men, 3 women; age, 42+/-9 y; range, 26-57 y) with transfemoral amputation. Research participants were long-term users of a mechanical prosthesis (20+/-10 y as an amputee; range, 3-36 y). They were fitted with a microprocessor-controlled knee prosthesis and allowed to acclimate (mean time, 18+/-8 wk) before being retested. Objective measurements of energy efficiency and total daily energy expenditure were obtained. The Prosthetic Evaluation Questionnaire was used to gather subjective feedback from the participants. Subjects demonstrated significantly increased physical activity-related energy expenditure levels in the participant's free-living environment (P=.04) after wearing the microprocessor-controlled prosthetic knee joint. There was no significant difference in the energy efficiency of walking (P=.34). When using the microprocessor-controlled knee, the subjects expressed increased satisfaction in their daily lives (P=.02). People ambulating with a microprocessor-controlled knee significantly increased their physical activity during daily life, outside the laboratory setting, and expressed an increased quality of life.

Amputee socks: thickness of multiple socks.

PubMed

Cagle, John C; Yu, Alan J; Ciol, Marcia A; Sanders, Joan E

2014-10-01

It is unclear how total sock ply and thickness are related when more than one sock is worn. The objectives were to determine whether the thickness of one multi-ply amputee sock of ply P was the same as the thickness of a stack of reduced-ply socks of total ply P, and whether the thickness of N single socks stacked one on top of the other was equal to the sum (1 to N) of the single sock thicknesses. Using a custom instrument, compressive stresses were applied while sock thickness was measured. The thickness of one multi-ply sock of ply P was typically less than the thickness of a stack of reduced-ply socks of total ply P. The thickness of N single socks stacked one on top of the other was approximately equal to the sum (1 to N) of the single sock thicknesses. Our findings suggest three 1-ply socks to be 20% greater in thickness than one 3-ply sock, and one 3-ply + two 1-ply socks to be 30% greater in thickness than one 5-ply sock. © The International Society for Prosthetics and Orthotics 2013.

Amputee Socks: Thickness of Multiple Socks

PubMed Central

Cagle, John C; Yu, Alan J; Ciol, Marcia A; Sanders, JE

2015-01-01

Background and Aim It is unclear how total sock ply and thickness are related when more than one sock is worn. The objectives were to determine if the thickness of one multi-ply amputee sock of ply P was the same as the thickness of a stack of reduced-ply socks of total ply P; and if the thickness of N single socks stacked one on top of the other was equal to the sum (1 to N) of the single sock thicknesses. Technique Using a custom instrument, compressive stresses were applied while sock thickness was measured. Discussion The thickness of one multi-ply sock of ply P was typically less than the thickness of a stack of reduced-ply socks of total ply P. The thickness of N single socks stacked one on top of the other was approximately equal to the sum (1 to N) of the single sock thicknesses. Clinical Relevance Our findings suggest three 1-ply socks to be 20% greater in thickness than one 3-ply sock, and one 3-ply + two 1-ply socks to be 30% greater in thickness than one 5-ply sock. PMID:24240023

Classification of motor intent in transradial amputees using sonomyography and spatio-temporal image analysis

NASA Astrophysics Data System (ADS)

Hariharan, Harishwaran; Aklaghi, Nima; Baker, Clayton A.; Rangwala, Huzefa; Kosecka, Jana; Sikdar, Siddhartha

2016-04-01

In spite of major advances in biomechanical design of upper extremity prosthetics, these devices continue to lack intuitive control. Conventional myoelectric control strategies typically utilize electromyography (EMG) signal amplitude sensed from forearm muscles. EMG has limited specificity in resolving deep muscle activity and poor signal-to-noise ratio. We have been investigating alternative control strategies that rely on real-time ultrasound imaging that can overcome many of the limitations of EMG. In this work, we present an ultrasound image sequence classification method that utilizes spatiotemporal features to describe muscle activity and classify motor intent. Ultrasound images of the forearm muscles were obtained from able-bodied subjects and a trans-radial amputee while they attempted different hand movements. A grid-based approach is used to test the feasibility of using spatio-temporal features by classifying hand motions performed by the subjects. Using the leave-one-out cross validation on image sequences acquired from able-bodied subjects, we observe that the grid-based approach is able to discern four hand motions with 95.31% accuracy. In case of the trans-radial amputee, we are able to discern three hand motions with 80% accuracy. In a second set of experiments, we study classification accuracy by extracting spatio-temporal sub-sequences the depict activity due to the motion of local anatomical interfaces. Short time and space limited cuboidal sequences are initially extracted and assigned an optical flow behavior label, based on a response function. The image space is clustered based on the location of cuboids and features calculated from the cuboids in each cluster. Using sequences of known motions, we extract feature vectors that describe said motion. A K-nearest neighbor classifier is designed for classification experiments. Using the leave-one-out cross validation on image sequences for an amputee subject, we demonstrate that the classifier is

Can the Nerve Growth Factor promote the reinnervation of the transplanted heart?

PubMed

Galli, Alessio

2014-02-01

The activity of the heart is widely regulated by the autonomous nervous system. This important mechanism of control may be impaired in chronic diseases such as heart failure or lost in those patients who undergo heart transplantation, owing to the surgical interruption of cardiac nerves in the transplanted heart. It has been demonstrated that spontaneous reinnervation can occur in transplanted hearts and is associated with an improvement in cardiac function. However, this process may require many years and the restoration of a proper cardiac innervation and functioning during exercise is never complete. In this perspective, the Nerve Growth Factor (NGF) and other neurotrophic hormones might ameliorate cardiac innervation in the transplanted heart and should be tried in animal models. Endothelial cells engineered with a viral vector to overexpress the NGF might be engrafted in the heart and integrate into cardiac small vessels, thus providing a source of neurotrophic factors which might promote and direct regrowth and axonal sprouting of cardiac nerves. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analyzing at-home prosthesis use in unilateral upper-limb amputees to inform treatment & device design.

PubMed

Spiers, Adam J; Resnik, Linda; Dollar, Aaron M

2017-07-01

New upper limb prosthetic devices are continuously being developed by a variety of industrial, academic, and hobbyist groups. Yet, little research has evaluated the long term use of currently available prostheses in daily life activities, beyond laboratory or survey studies. We seek to objectively measure how experienced unilateral upper limb prosthesis-users employ their prosthetic devices and unaffected limb for manipulation during everyday activities. In particular, our goal is to create a method for evaluating all types of amputee manipulation, including non-prehensile actions beyond conventional grasp functions, as well as to examine the relative use of both limbs in unilateral and bilateral cases. This study employs a head-mounted video camera to record participant's hands and arms as they complete unstructured domestic tasks within their own homes. A new 'Unilateral Prosthesis-User Manipulation Taxonomy' is presented based observations from 10 hours of recorded videos. The taxonomy addresses manipulation actions of the intact hand, prostheses, bilateral activities, and environmental feature-use (aiïordances). Our preliminary results involved tagging 23 minute segments of the full videos from 3 amputee participants using the taxonomy. This resulted in over 2,300 tag instances. Observations included that non-prehensile interactions outnumbered prehensile interactions in the affected limb for users with more distal amputation that allowed arm mobility.

Energy Expenditure and Activity of Transfemoral Amputees Using Mechanical and Microprocessor-Controlled Prosthetic Knees

PubMed Central

Kaufman, Kenton R.; Levine, James A.; Brey, Robert H.; McCrady, Shelly K.; Padgett, Denny J.; Joyner, Michael J.

2009-01-01

Objective To quantify the energy efficiency of locomotion and free-living physical activity energy expenditure of transfemoral amputees using a mechanical and microprocessor-controlled prosthetic knee. Design Repeated-measures design to evaluate comparative functional outcomes. Setting Exercise physiology laboratory and community free-living environment. Participants Subjects (N=15; 12 men, 3 women; age, 42±9y; range, 26 –57y) with transfemoral amputation. Intervention Research participants were long-term users of a mechanical prosthesis (20±10y as an amputee; range, 3–36y). They were fitted with a microprocessor-controlled knee prosthesis and allowed to acclimate (mean time, 18±8wk) before being retested. Main Outcome Measures Objective measurements of energy efficiency and total daily energy expenditure were obtained. The Prosthetic Evaluation Questionnaire was used to gather subjective feedback from the participants. Results Subjects demonstrated significantly increased physical activity–related energy expenditure levels in the participant’s free-living environment (P=.04) after wearing the microprocessor-controlled prosthetic knee joint. There was no significant difference in the energy efficiency of walking (P=.34). When using the microprocessor-controlled knee, the subjects expressed increased satisfaction in their daily lives (P=.02). Conclusions People ambulating with a microprocessor-controlled knee significantly increased their physical activity during daily life, outside the laboratory setting, and expressed an increased quality of life. PMID:18586142

Plasticity of the transverse tubules following denervation and subsequent reinnervation in rat slow and fast muscle fibres.

PubMed

Takekura, Hiroaki; Tamaki, Hiroyuki; Nishizawa, Tomie; Kasuga, Norikatsu

2003-01-01

We have studied the effects of short term denervation followed by reinnervation on the ultrastructure of the membrane systems and on the content of and distribution of key proteins involved in calcium regulation of fast-twitch (FT) extensor digitorum longus (EDL) and slow-twitch (ST) soleus (SOL) muscle fibres. Ischiadic nerve freezing resulted in total lack of neuromuscular transmission for 3 days followed by a slow recovery, but no decline in twitch force elicited by direct stimulation. The latter measurements indicate no significant atrophy within this time frame. The membrane systems of skeletal muscle fibres were visualized using Ca92+)-K3Fe(CN)6-OsO4 techniques and observed using a high voltage electron microscope. [3H]nitrendipine binding was used to detect levels of dihydropyridine receptor (DHPR) expression. The Ca2+ pumping free sarcoplasmic reticulum domains were not affected by the denervation, but the Ca2+ release domains were dramatically increased, particularly in the FT-EDL muscle fibres. The increase is evidenced by a doubling up of the areas of contacts between SR and transverse (t-) tubules, so that in place of the normal triadic arrangement, pentadic and heptadic junctions, formed by multiple interacting layers of ST and t-tubules are seen. Frequency of pentads and heptads increases and declines in parallel to the denervation and reinnervation but with a delay. Immunofluorecence and electron microscopy observations show presence of DHPR and ryanodine receptor clusters at pentads and heptads junctions. A significant (P < 0.01) positive correlation between the level of [3H]nitrendipine binding component and the frequency pentads and heptads was observed in both the FT-EDL and ST-SOL muscle fibres indicating that overexpression of DHPRs accompanies the build up extra junctional contacts. The results indicate that denervation reversibly affects the domains of the membrane systems involved in excitation-contraction coupling.

A combined kinematic and kinetic analysis at the residuum/socket interface of a knee-disarticulation amputee.

PubMed

Tang, Jinghua; McGrath, Michael; Hale, Nick; Jiang, Liudi; Bader, Dan; Laszczak, Piotr; Moser, David; Zahedi, Saeed

2017-11-01

The bespoke interface between a lower limb residuum and a prosthetic socket is critical for an amputee's comfort and overall rehabilitation outcomes. Analysis of interface kinematics and kinetics is important to gain full understanding of the interface biomechanics, which could aid clinical socket fit, rehabilitation and amputee care. This pilot study aims to investigate the dynamic correlation between kinematic movement and kinetic stresses at the interface during walking tests on different terrains. One male, knee disarticulation amputee participated in the study. He was asked to walk on both a level surface and a 5° ramped surface. The movement between the residuum and the socket was evaluated by the angular and axial couplings, based on the outputs from a 3D motion capture system. The corresponding kinetic stresses at anterior-proximal (AP), posterior-proximal (PP) and anterior-distal (AD) locations of the residuum were measured, using individual stress sensors. Approximately 8° of angular coupling and up to 32 mm of axial coupling were measured when walking on different terrains. The direction of the angular coupling shows strong correlation with the pressure difference between the PP and AP sensors. Higher pressure was obtained at the PP location than the AP location during stance phase, associated with the direction of the angular coupling. A strong correlation between axial coupling length, L, and longitudinal shear was also evident at the PP and AD locations i.e. the shortening of L corresponds to the increase of shear in the proximal direction. Although different terrains did not affect these correlations in principle, interface kinematic and kinetic values suggested that gait changes can induce modifications to the interface biomechanics. It is envisaged that the reported techniques could be potentially used to provide combined kinematics and kinetics for the understanding of biomechanics at the residuum/socket interface, which may play an important

Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis

PubMed Central

Simon, Ann M.; Hargrove, Levi J.

2016-01-01

Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions) and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed. PMID:26807889

The Effect of Prosthetic Foot Push-off on Mechanical Loading Associated with Knee Osteoarthritis in Lower Extremity Amputees

PubMed Central

Morgenroth, David C.; Segal, Ava D.; Zelik, Karl E.; Czerniecki, Joseph M.; Klute, Glenn K.; Adamczyk, Peter G.; Orendurff, Michael S.; Hahn, Michael E.; Collins, Steven H.; Kuo, Art D.

2011-01-01

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope = −0.72 +/− 0.22; p=0.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope = −0.34 +/− 0.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. PMID:21803584

The effect of prosthetic foot push-off on mechanical loading associated with knee osteoarthritis in lower extremity amputees.

PubMed

Morgenroth, David C; Segal, Ava D; Zelik, Karl E; Czerniecki, Joseph M; Klute, Glenn K; Adamczyk, Peter G; Orendurff, Michael S; Hahn, Michael E; Collins, Steven H; Kuo, Art D

2011-10-01

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope=-.72±.22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope=-.34±.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. Published by Elsevier B.V.

An instrument for monitoring stump oedema and shrinkage in amputees.

PubMed

Fernie, G R; Holliday, P J; Lobb, R J

1978-08-01

A new system for measuring the cross-sectional area profiles of amputation stumps and whole limbs has been designed at the Amputee Research Centre. The instrument consists of a cylindrical tank supported on an elevator. The tank is raised to the height of the amputation stump and filled with water. A graph of the cross-sectional area profile of the amputation stump is generated by a mini-computer as the elevator descends. The cross-sectional area (A) is calculated from the expression: formula: (see text) where Hw = height of water in the tank He = height of the elevator Ac = a constant, related to the size of the measuring tank. This paper describes the instrument, which may find application in many other areas where there is a need to study shape.

Double nerve intraneural interface implant on a human amputee for robotic hand control.

PubMed

Rossini, Paolo M; Micera, Silvestro; Benvenuto, Antonella; Carpaneto, Jacopo; Cavallo, Giuseppe; Citi, Luca; Cipriani, Christian; Denaro, Luca; Denaro, Vincenzo; Di Pino, Giovanni; Ferreri, Florinda; Guglielmelli, Eugenio; Hoffmann, Klaus-Peter; Raspopovic, Stanisa; Rigosa, Jacopo; Rossini, Luca; Tombini, Mario; Dario, Paolo

2010-05-01

The principle underlying this project is that, despite nervous reorganization following upper limb amputation, original pathways and CNS relays partially maintain their function and can be exploited for interfacing prostheses. Aim of this study is to evaluate a novel peripheral intraneural multielectrode for multi-movement prosthesis control and for sensory feed-back, while assessing cortical reorganization following the re-acquired stream of data. Four intrafascicular longitudinal flexible multielectrodes (tf-LIFE4) were implanted in the median and ulnar nerves of an amputee; they reliably recorded output signals for 4 weeks. Artificial intelligence classifiers were used off-line to analyse LIFE signals recorded during three distinct hand movements under voluntary order. Real-time control of motor output was achieved for the three actions. When applied off-line artificial intelligence reached >85% real-time correct classification of trials. Moreover, different types of current stimulation were determined to allow reproducible and localized hand/fingers sensations. Cortical organization was observed via TMS in parallel with partial resolution of symptoms due to the phantom-limb syndrome (PLS). tf-LIFE4s recorded output signals in human nerves for 4 weeks, though the efficacy of sensory stimulation decayed after 10 days. Recording from a number of fibres permitted a high percentage of distinct actions to be classified correctly. Reversal of plastic changes and alleviation of PLS represent corollary findings of potential therapeutic benefit. This study represents a breakthrough in robotic hand use in amputees. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Assessing physical function in adult acquired major upper-limb amputees by combining the Disabilities of the Arm, Shoulder and Hand (DASH) Outcome Questionnaire and clinical examination.

PubMed

Ostlie, Kristin; Franklin, Rosemary J; Skjeldal, Ola H; Skrondal, Anders; Magnus, Per

2011-10-01

To describe physical function in adult acquired major upper-limb amputees (ULAs) by combining self-assessed arm function and physical measures obtained by clinical examinations; to estimate associations between background factors and self-assessed arm function in ULAs; and to assess whether clinical examination findings may be used to detect reduced arm function in unilateral ULAs. postal questionnaires and clinical examinations. Norwegian ULA population. Clinical examinations performed at 3 clinics. Questionnaires: population-based sample (n=224; 57.4% response rate). Clinical examinations: combined referred sample and convenience sample of questionnaire responders (n=70; 83.3% of those invited). SURVEY inclusion criteria: adult acquired major upper-limb amputation, resident in Norway, mastering of spoken and written Norwegian. Not applicable. The Disabilities of the Arm, Shoulder and Hand (DASH) Outcome Questionnaire, and clinical examination of joint motion and muscle strength with and without prostheses. Mean DASH score was 22.7 (95% confidence interval [CI], 20.3-25.0); in bilateral amputees, 35.7 (95% CI, 23.0-48.4); and in unilateral amputees, 22.1 (95% CI, 19.8-24.5). A lower unilateral DASH score (better function) was associated with paid employment (vs not in paid employment: adjusted regression coefficient [aB]=-5.40, P=.033; vs students: aB=-13.88, P=.022), increasing postamputation time (aB=-.27, P=.001), and Norwegian ethnicity (aB=-14.45, P<.001). At clinical examination, we found a high frequency of impaired neck mobility and varying frequencies of impaired joint motion and strength at the shoulder, elbow, and forearm level. Prosthesis wear was associated with impaired joint motion in all upper-limb joints (P<.006) and with reduced shoulder abduction strength (P=.002). Impaired without-prosthesis joint motion in shoulder flexion (ipsilateral: aB=12.19, P=.001) and shoulder abduction (ipsilateral: aB=12.01, P=.005; contralateral: aB=28.82, P=.004

Effects of sensory augmentation on postural control and gait symmetry of transfemoral amputees: a case description.

PubMed

Pagel, Anna; Arieta, Alejandro Hernandez; Riener, Robert; Vallery, Heike

2016-10-01

Despite recent advances in leg prosthetics, transfemoral amputees still experience limitations in postural control and gait symmetry. It has been hypothesized that artificial sensory information might improve the integration of the prosthesis into the human sensory-motor control loops and, thus, reduce these limitations. In three transfemoral amputees, we investigated the effect of Electrotactile Moving Sensation for Sensory Augmentation (EMSSA) without training and present preliminary findings. Experimental conditions included standing with open/closed eyes on stable/unstable ground as well as treadmill walking. For standing conditions, spatiotemporal posturographic measures and sample entropy were derived from the center of pressure. For walking conditions, step length and stance duration were calculated. Conditions without feedback showed effects congruent with findings in the literature, e.g., asymmetric weight bearing and step length, and validated the collected data. During standing, with EMSSA a tendency to influence postural control in a negative way was found: Postural control was less effective and less efficient and the prosthetic leg was less involved. Sample entropy tended to decrease, suggesting that EMSSA demanded increased attention. During walking, with EMSSA no persistent positive effect was found. This contrasts the positive subjective assessment and the positive effect on one subject's step length.

Clinical field follow-up of high density polyethylene (HDPE)-Jaipur prosthetic technology for trans-femoral amputees.

PubMed

Jensen, J S; Craig, J G; Mtalo, L B; Zelaya, C M

2004-08-01

The purpose of this study was to examine the outcome of the application of the high density polyethylene (HDPE)-Jaipur prosthetic construction in fitting trans-femoral amputees in a number of projects throughout the developing world. Projects in Honduras, Uganda and India were included. One hundred and fifty eight (158) patients had been provided with the HDPE-Jaipur prosthesis and of these 72 were seen for a clinical and technical follow-up after a median of 32 months. More than half the amputees seen had amputation due to trauma and the remainder due to disease. Fabrication and fitting in the three projects was carried out by individuals who had undertaken a three week training course provided by Bhagwan Mahaveer Viklang Sahayata Samiti limb centre in Jaipur. The individuals involved had limited background training in prosthetics. Craftsmanship and fit were assessed as being poor in 86% of cases. Failure requiring replacement of components was observed in 50% of cases. There was low patient satisfaction (58%) and patient compliance (65%). The outcome was considered unsatisfactory both technically and clinically. This was a reflection of the inadequacies of the prosthetic construction, particularly the knee joint, and the inadequate training of those involved in fitting and fabrication of the devices.

Influence of malalignment on socket reaction moments during gait in amputees with transtibial prostheses.

PubMed

Boone, David A; Kobayashi, Toshiki; Chou, Teri G; Arabian, Adam K; Coleman, Kim L; Orendurff, Michael S; Zhang, Ming

2013-04-01

Alignment - the process and measured orientation of the prosthetic socket relative to the foot - is important for proper function of a transtibial prosthesis. Prosthetic alignment is performed by prosthetists using visual gait observation and amputees' feedback. The aim of this study was to investigate the effect of transtibial prosthesis malalignment on the moments measured at the base of the socket: the socket reaction moments. Eleven subjects with transtibial amputation were recruited from the community. An instrumented prosthesis alignment component was used to measure socket reaction moments during ambulation under 17 alignment conditions, including nominally aligned using conventional clinical methods, and angle perturbations of 3° and 6° (flexion, extension, abduction, and adduction) and translation perturbations of 5mm and 10mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. Coronal alignment perturbations caused systematic changes in the coronal socket reaction moments. All angle and translation perturbations revealed statistically significant differences on coronal socket reaction moments compared to the nominal alignment at 30% and 75% of stance phase (P<0.05). The effect of sagittal alignment perturbations on sagittal socket reaction moments was not as responsive as that of the coronal perturbations. The sagittal angle and translation perturbations of the socket led to statistically significant changes in minimum moment, maximum moment, and moments at 45% of stance phase in the sagittal plane. Therefore, malalignment affected the socket reaction moments in amputees with transtibial prostheses. Copyright © 2012 Elsevier B.V. All rights reserved.

Prosthesis use in adult acquired major upper-limb amputees: patterns of wear, prosthetic skills and the actual use of prostheses in activities of daily life.

PubMed

Østlie, Kristin; Lesjø, Ingrid Marie; Franklin, Rosemary Joy; Garfelt, Beate; Skjeldal, Ola Hunsbeth; Magnus, Per

2012-11-01

To describe patterns of prosthesis wear and perceived prosthetic usefulness in adult acquired upper-limb amputees (ULAs). To describe prosthetic skills in activities of daily life (ADL) and the actual use of prostheses in the performance of ADL tasks. To estimate the influence of prosthetic skills on actual prosthesis use and the influence of background factors on prosthetic skills and actual prosthesis use. Cross-sectional study analysing population-based questionnaire data (n = 224) and data from interviews and clinical testing in a referred/convenience sample of prosthesis-wearing ULAs (n = 50). Effects were analysed using linear regression. 80.8% wore prostheses. 90.3% reported their most worn prosthesis as useful. Prosthetic usefulness profiles varied with prosthetic type. Despite demonstrating good prosthetic skills, the amputees reported actual prosthesis use in only about half of the ADL tasks performed in everyday life. In unilateral amputees, increased actual use was associated with sufficient prosthetic training and with the use of myoelectric vs cosmetic prostheses, regardless of amputation level. Prosthetic skills did not affect actual prosthesis use. No background factors showed significant effect on prosthetic skills. Most major ULAs wear prostheses. Individualised prosthetic training and fitting of myoelectric rather than passive prostheses may increase actual prosthesis use in ADL.

The effects of prosthetic foot type and visual alteration on postural steadiness in below-knee amputees

PubMed Central

2014-01-01

Background Achieving independent upright posture has known to be one of the main goals in rehabilitation following lower limb amputation. The purpose of this study was to compare postural steadiness of below knee amputees with visual alterations while wearing three different prosthetic feet. Methods Ten male below-knee amputees were instructed to stand quietly on the Biodex® balance platform while wearing solid ankle cushion heel (SACH), single axis (SA) and energy storage and release (ESAR) prosthetic foot under different visual input conditions (eyes-opened and eyes-closed). The overall stability index (OSI), anterior- posterior stability index (APSI), and medial-lateral stability index (MLSI) were computed. Perceived balance assessment of each foot was evaluated using Activities-specific Balance Confidence (ABC) score. Results The findings highlights that SACH showed lowest overall stability index (indicating less body sway) during eyes-opened (OSI: SACH = 1.09, SA = 1.58, ESAR = 1.59) and SA showed lowest overall stability index during eyes-closed (OSI: SACH = 2.52, SA = 2.30, ESAR = 2.76) condition. However, overall stability indexes between foot types did not differ significantly during eyes-opened or eyes-closed (p = 0.651). There was a trend of instability which occurred more in medial-lateral compared to anterior-posterior direction for all foot types, with significant result in ESAR foot(eyes-opened: MLSI = 1.59, APSI = 0.65, p = 0.034; eyes-closed: MLSI = 2.76, APSI = 1.80, p = 0.017, respectively). When comparing between visual conditions, stability score was significantly higher during eyes-closed compared to eyes-opened situations for SACH and ESAR foot (eyes-closed vs opened; SACH OSI: 3.43 vs 1.71, p = 0.018 and MLSI: 3.43 vs 1.71, p = 0.018; ESAR OSI: 3.58 vs 1.86, p = 0.043 and APSI: 1.80 vs 0.65, p = 0.027). Conclusions The results of this study suggested postural steadiness in

The Effect of a Microprocessor Prosthetic Foot on Function and Quality of Life in Transtibial Amputees Who Are Limited Community Ambulators

DTIC Science & Technology

with greater range of motion and active power, will translate into improved functional performance, ambulatory safety (risk of falls) and quality of... life in trans-tibial amputees (TTA) who function as limited community ambulators. We will assess these outcomes in 54 veterans with TTA by randomizing

The Role of the Environment in Eliciting Phantom-Like Sensations in Non-Amputees

PubMed Central

Lewis, Elizabeth; Lloyd, Donna M.; Farrell, Martin J.

2013-01-01

Following the amputation of a limb, many amputees report that they can still vividly perceive its presence despite conscious knowledge that it is not physically there. However, our ability to probe the mental representation of this experience is limited by the intractable and often distressing pain associated with amputation. Here, we present a method for eliciting phantom-like experiences in non-amputees using a variation of the rubber hand illusion in which a finger has been removed from the rubber hand. An interpretative phenomenological analysis revealed that the structure of this experience shares a wide range of sensory attributes with subjective reports of phantom limb experience. For example, when the space where the ring finger should have been on the rubber hand was stroked, 93% of participants (i.e., 28/30) reported the vivid presence of a finger that they could not see and a total of 57% (16/28) of participants who felt that the finger was present reported one or more additional sensory qualities such as tingling or numbness (25%; 7/28) and alteration in the perceived size of the finger (50%; 14/28). These experiences indicate the adaptability of body experience and share some characteristics of the way that phantom limbs are described. Participants attributed changes to the shape and size of their “missing” finger to the way in which the experimenter mimed stroking in the area occupied by the missing finger. This alteration of body perception is similar to the phenomenon of telescoping experienced by people with phantom limbs and suggests that our sense of embodiment not only depends on internal body representations but on perceptual information coming from peripersonal space. PMID:23355829

Thorax, pelvis and hip pattern in the frontal plane during walking in unilateral transtibial amputees: biomechanical analysis

PubMed Central

Molina-Rueda, Francisco; Alguacil-Diego, Isabel M.; Cuesta-Gómez, Alicia; Iglesias-Giménez, Javier; Martín-Vivaldi, Andrés; Miangolarra-Page, Juan C.

2014-01-01

Background: Lower limb amputees exhibit postural control deficits during standing which can affect their walking ability. Objectives: The primary purpose of the present study was to analyze the thorax, pelvis, and hip kinematics and the hip internal moment in the frontal plane during gait in subjects with Unilateral Transtibial Amputation (UTA). Method: The participants included 25 people with UTA and 25 non-amputees as control subjects. Gait analysis was performed using the Vicon(r) Motion System. We analyzed the motion of the thorax, pelvis, and hip (kinematics) as well as the hip internal moment in the frontal plane. Results: The second peak of the hip abductor moment was significantly lower on the prosthetic side than on the sound side (p=.01) and the control side (right: p=.01; left: p=.01). During middle stance, the opposite side of the pelvis was higher on the prosthetic side compared to the control side (right: p=.01: left: p=.01). Conclusions: The joint internal moment at the hip in the frontal plane was lower on the prosthetic side than on the sound side or the control side. Thorax and pelvis kinematics were altered during the stance phase on the prosthetic side, presumably because there are mechanisms which affect postural control during walking. PMID:25003278

Real-time, ultrasound-based control of a virtual hand by a trans-radial amputee.

PubMed

Baker, Clayton A; Akhlaghi, Nima; Rangwala, Huzefa; Kosecka, Jana; Sikdar, Siddhartha

2016-08-01

Advancements in multiarticulate upper-limb prosthetics have outpaced the development of intuitive, non-invasive control mechanisms for implementing them. Surface electromyography is currently the most popular non-invasive control method, but presents a number of drawbacks including poor deep-muscle specificity. Previous research established the viability of ultrasound imaging as an alternative means of decoding movement intent, and demonstrated the ability to distinguish between complex grasps in able-bodied subjects via imaging of the anterior forearm musculature. In order to translate this work to clinical viability, able-bodied testing is insufficient. Amputation-induced changes in muscular geometry, dynamics, and imaging characteristics are all likely to influence the effectiveness of our existing techniques. In this work, we conducted preliminary trials with a transradial amputee participant to assess these effects, and potentially elucidate necessary refinements to our approach. Two trials were performed, the first using a set of three motion types, and the second using four. After a brief training period in each trial, the participant was able to control a virtual prosthetic hand in real-time; attempted grasps were successfully classified with a rate of 77% in trial 1, and 71% in trial 2. While the results are sub-optimal compared to our previous able-bodied testing, they are a promising step forward. More importantly, the data collected during these trials can provide valuable information for refining our image processing methods, especially via comparison to previously acquired data from able-bodied individuals. Ultimately, further work with amputees is a necessity for translation towards clinical application.

A motion-classification strategy based on sEMG-EEG signal combination for upper-limb amputees.

PubMed

Li, Xiangxin; Samuel, Oluwarotimi Williams; Zhang, Xu; Wang, Hui; Fang, Peng; Li, Guanglin

2017-01-07

Most of the modern motorized prostheses are controlled with the surface electromyography (sEMG) recorded on the residual muscles of amputated limbs. However, the residual muscles are usually limited, especially after above-elbow amputations, which would not provide enough sEMG for the control of prostheses with multiple degrees of freedom. Signal fusion is a possible approach to solve the problem of insufficient control commands, where some non-EMG signals are combined with sEMG signals to provide sufficient information for motion intension decoding. In this study, a motion-classification method that combines sEMG and electroencephalography (EEG) signals were proposed and investigated, in order to improve the control performance of upper-limb prostheses. Four transhumeral amputees without any form of neurological disease were recruited in the experiments. Five motion classes including hand-open, hand-close, wrist-pronation, wrist-supination, and no-movement were specified. During the motion performances, sEMG and EEG signals were simultaneously acquired from the skin surface and scalp of the amputees, respectively. The two types of signals were independently preprocessed and then combined as a parallel control input. Four time-domain features were extracted and fed into a classifier trained by the Linear Discriminant Analysis (LDA) algorithm for motion recognition. In addition, channel selections were performed by using the Sequential Forward Selection (SFS) algorithm to optimize the performance of the proposed method. The classification performance achieved by the fusion of sEMG and EEG signals was significantly better than that obtained by single signal source of either sEMG or EEG. An increment of more than 14% in classification accuracy was achieved when using a combination of 32-channel sEMG and 64-channel EEG. Furthermore, based on the SFS algorithm, two optimized electrode arrangements (10-channel sEMG + 10-channel EEG, 10-channel sEMG + 20-channel

Improving the Robustness of Real-Time Myoelectric Pattern Recognition against Arm Position Changes in Transradial Amputees

PubMed Central

Geng, Yanjuan; Wei, Yue

2017-01-01

Previous studies have showed that arm position variations would significantly degrade the classification performance of myoelectric pattern-recognition-based prosthetic control, and the cascade classifier (CC) and multiposition classifier (MPC) have been proposed to minimize such degradation in offline scenarios. However, it remains unknown whether these proposed approaches could also perform well in the clinical use of a multifunctional prosthesis control. In this study, the online effect of arm position variation on motion identification was evaluated by using a motion-test environment (MTE) developed to mimic the real-time control of myoelectric prostheses. The performance of different classifier configurations in reducing the impact of arm position variation was investigated using four real-time metrics based on dataset obtained from transradial amputees. The results of this study showed that, compared to the commonly used motion classification method, the CC and MPC configurations improved the real-time performance across seven classes of movements in five different arm positions (8.7% and 12.7% increments of motion completion rate, resp.). The results also indicated that high offline classification accuracy might not ensure good real-time performance under variable arm positions, which necessitated the investigation of the real-time control performance to gain proper insight on the clinical implementation of EMG-pattern-recognition-based controllers for limb amputees. PMID:28523276

Short- and Long-Term Learning of Feedforward Control of a Myoelectric Prosthesis with Sensory Feedback by Amputees.

PubMed

Strbac, Matija; Isakovic, Milica; Belic, Minja; Popovic, Igor; Simanic, Igor; Farina, Dario; Keller, Thierry; Dosen, Strahinja

2017-11-01

Human motor control relies on a combination of feedback and feedforward strategies. The aim of this study was to longitudinally investigate artificial somatosensory feedback and feedforward control in the context of grasping with myoelectric prosthesis. Nine amputee subjects performed routine grasping trials, with the aim to produce four levels of force during four blocks of 60 trials across five days. The electrotactile force feedback was provided in the second and third block using multipad electrode and spatial coding. The first baseline and last validation block (open-loop control) evaluated the effects of long- (across sessions) and short-term (within session) learning, respectively. The outcome measures were the absolute error between the generated and target force, and the number of force saturations. The results demonstrated that the electrotactile feedback improved the performance both within and across sessions. In the validation block, the performance did not significantly decrease and the quality of open-loop control (baseline) improved across days, converging to the performance characterizing closed-loop control. This paper provides important insights into the feedback and feedforward processes in prosthesis control, contributing to the better understanding of the role and design of feedback in prosthetic systems.

Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee.

PubMed

Hafner, Brian J; Willingham, Laura L; Buell, Noelle C; Allyn, Katheryn J; Smith, Douglas G

2007-02-01

To evaluate differences in function, performance, and preference between mechanical and microprocessor prosthetic knee control technologies. A-B-A-B reversal design. Home, community, and laboratory environments. Twenty-one unilateral, transfemoral amputees. Mechanical control prosthetic knee versus microprocessor control prosthetic knee (Otto Bock C-Leg). Stair rating, hill rating and time, obstacle course time, divided attention task accuracy and time, Amputee Mobility Predictor score, step activity, Prosthesis Evaluation Questionnaire score, Medical Outcomes Study 36-Item Short-Form Health Survey score, self-reported frequency of stumbles and falls, and self-reported concentration required for ambulation. Stair descent score, hill descent time, and hill sound-side step length showed significant (P<.01) improvement with the C-Leg. Users reported a significant (P<.05) decrease in frequency of stumbles and falls, frustration with falling, and difficulty in multitasking while using the microprocessor knee. Subject satisfaction with the C-Leg was significantly (P<.001) greater than the mechanical control prosthesis. The study population showed improved performance when negotiating stairs and hills, reduced frequency of stumbling and falling, and a preference for the microprocessor control C-Leg as compared with the mechanical control prosthetic knee.

Electrical stimulation of paralyzed vibrissal muscles reduces endplate reinnervation and does not promote motor recovery after facial nerve repair in rats.

PubMed

Sinis, Nektarios; Horn, Frauke; Genchev, Borislav; Skouras, Emmanouil; Merkel, Daniel; Angelova, Srebrina K; Kaidoglou, Katerina; Michael, Joern; Pavlov, Stoyan; Igelmund, Peter; Schaller, Hans-Eberhard; Irintchev, Andrey; Dunlop, Sarah A; Angelov, Doychin N

2009-10-01

The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.

A new method to quantify liner deformation within a prosthetic socket for below knee amputees.

PubMed

Lenz, Amy L; Johnson, Katie A; Bush, Tamara Reid

2018-06-06

Many amputees who wear a leg prosthesis develop significant skin wounds on their residual limb. The exact cause of these wounds is unclear as little work has studied the interface between the prosthetic device and user. Our research objective was to develop a quantitative method for assessing displacement patterns of the gel liner during walking for patients with transtibial amputation. Using a reflective marker system and a custom clear socket, evaluations were conducted with a clear transparent test socket mounted over a plaster limb model and a deformable limb model. Distances between markers placed on the limb were measured with a digital caliper and then compared with data from the motion capture system. Additionally, the rigid plaster set-up was moved in the capture volume to simulate walking and evaluate if inter-marker distances changed in comparison to static data. Dynamic displacement trials were then collected to measure changes in inter-marker distance due to vertical elongation of the gel liner. Static and dynamic inter-marker distances within day and across days confirmed the ability to accurately capture displacements using this new approach. These results encourage this novel method to be applied to a sample of amputee patients during walking to assess displacements and the distribution of the liner deformation within the socket. The ability to capture changes in deformation of the gel liner will provide new data that will enable clinicians and researchers to improve design and fit of the prosthesis so the incidence of pressure ulcers can be reduced. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Randomized, Controlled Trial of Mirror Therapy for Upper Extremity Phantom Limb Pain in Male Amputees.

PubMed

Finn, Sacha B; Perry, Briana N; Clasing, Jay E; Walters, Lisa S; Jarzombek, Sandra L; Curran, Sean; Rouhanian, Minoo; Keszler, Mary S; Hussey-Andersen, Lindsay K; Weeks, Sharon R; Pasquina, Paul F; Tsao, Jack W

2017-01-01

Phantom limb pain (PLP) is prevalent in patients post-amputation and is difficult to treat. We assessed the efficacy of mirror therapy in relieving PLP in unilateral, upper extremity male amputees. Fifteen participants from Walter Reed and Brooke Army Medical Centers were randomly assigned to one of two groups: mirror therapy ( n  = 9) or control ( n  = 6, covered mirror or mental visualization therapy). Participants were asked to perform 15 min of their assigned therapy daily for 5 days/week for 4 weeks. The primary outcome was pain as measured using a 100-mm Visual Analog Scale. Subjects in the mirror therapy group had a significant decrease in pain scores, from a mean of 44.1 (SD = 17.0) to 27.5 (SD = 17.2) mm ( p  = 0.002). In addition, there was a significant decrease in daily time experiencing pain, from a mean of 1,022 (SD = 673) to 448 (SD = 565) minutes ( p  = 0.003). By contrast, the control group had neither diminished pain ( p  = 0.65) nor decreased overall time experiencing pain ( p  = 0.49). A pain decrement response seen by the 10th treatment session was predictive of final efficacy. These results confirm that mirror therapy is an effective therapy for PLP in unilateral, upper extremity male amputees, reducing both severity and duration of daily episodes. NCT0030144 ClinicalTrials.gov.

Neo-phalloplasty with re-innervated latissimus dorsi free flap: a functional study of a novel technique.

PubMed

Ranno, R; Veselý, J; Hýza, P; Stupka, I; Justan, I; Dvorák, Z; Monni, N; Novák, P; Ranno, S

2007-01-01

Twenty two patients with gender dysphoria underwent neo-phalloplasties using a novel technique. Latissimus dorsi musculocutaneus re-innervated free flap was used to allow voluntary rigidity of the neo-penis. From the first 22 patients, 18 have obtained motoric function of reconstructed penis; the "paradox erection" was obtained. 14 patients came for examination after a follow-up period of mean 26.4 months. We evaluated the motility and shape changes of neo-phallus measuring its different size and dimension during relax and muscle contraction. The range of neo-phallus length in relaxed position was between 7 and 17 cm (mean 12.2 cm), its circumference in the same position had a range between 13 and 20 cm (mean 13.7 cm). All patients were able to contract the muscle with an average length reduction of 3.08 cm and an average circumference enlargement of 4 cm. In this study, the dimensions and motility were quantified demonstrating the neo-phallus function and size changes during sexual intercourse.

Diaphragmatic reinnervation in ventilator-dependent patients with cervical spinal cord injury and concomitant phrenic nerve lesions using simultaneous nerve transfers and implantable neurostimulators.

PubMed

Kaufman, Matthew R; Elkwood, Andrew I; Aboharb, Farid; Cece, John; Brown, David; Rezzadeh, Kameron; Jarrahy, Reza

2015-06-01

Patients who are ventilator dependent as a result of combined cervical spinal cord injury and phrenic nerve lesions are generally considered to be unsuitable candidates for diaphragmatic pacing due to loss of phrenic nerve integrity and denervation of the diaphragm. There is limited data regarding efficacy of simultaneous nerve transfers and diaphragmatic pacemakers in the treatment of this patient population. A retrospective review was conducted of 14 consecutive patients with combined lesions of the cervical spinal cord and phrenic nerves, and with complete ventilator dependence, who were treated with simultaneous microsurgical nerve transfer and implantation of diaphragmatic pacemakers. Parameters of interest included time to recovery of diaphragm electromyographic activity, average time pacing without the ventilator, and percent reduction in ventilator dependence. Recovery of diaphragm electromyographic activity was demonstrated in 13 of 14 (93%) patients. Eight of these 13 (62%) patients achieved sustainable periods (> 1 h/d) of ventilator weaning (mean = 10 h/d [n = 8]). Two patients recovered voluntary control of diaphragmatic activity and regained the capacity for spontaneous respiration. The one patient who did not exhibit diaphragmatic reinnervation remains within 12 months of initial treatment. Surgical intervention resulted in a 25% reduction (p < 0.05) in ventilator dependency. We have demonstrated that simultaneous nerve transfers and pacemaker implantation can result in reinnervation of the diaphragm and lead to successful ventilator weaning. Our favorable outcomes support consideration of this surgical method for appropriate patients who would otherwise have no alternative therapy to achieve sustained periods of ventilator independence. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Impact on the biomechanics of overground gait of using an 'Echelon' hydraulic ankle-foot device in unilateral trans-tibial and trans-femoral amputees.

PubMed

De Asha, Alan R; Munjal, Ramesh; Kulkarni, Jai; Buckley, John G

2014-08-01

If a prosthetic foot creates resistance to forwards shank rotation as it deforms during loading, it will exert a braking effect on centre of mass progression. The present study determines whether the centre of mass braking effect exerted by an amputee's habitual rigid 'ankle' foot was reduced when they switched to using an 'Echelon' hydraulic ankle-foot device. Nineteen lower limb amputees (eight trans-femoral, eleven trans-tibial) walked overground using their habitual dynamic-response foot with rigid 'ankle' or 'Echelon' hydraulic ankle-foot device. Analysis determined changes in how the centre of mass was transferred onto and above the prosthetic-foot, freely chosen walking speed, and spatio-temporal parameters of gait. When using the hydraulic device both groups had a smoother/more rapid progression of the centre of pressure beneath the prosthetic hindfoot (p≤0.001), and a smaller reduction in centre of mass velocity during prosthetic-stance (p<0.001). As a result freely chosen walking speed was higher in both groups when using the device (p≤0.005). In both groups stance and swing times and cadence were unaffected by foot condition whereas step length tended (p<0.07) to increase bilaterally when using the hydraulic device. Effect size differences between foot types were comparable across groups. Use of a hydraulic ankle-foot device reduced the foot's braking effect for both amputee groups. Findings suggest that attenuation of the braking effect from the foot in early stance may be more important to prosthetic-foot function than its ability to return energy in late stance. Copyright © 2014. Published by Elsevier Ltd.

A comparison of upper limb amputees and patients with upper limb injuries using the Disability of the Arm, Shoulder and Hand (DASH).

PubMed

Davidson, Judith

To use the Disability of the Arm Shoulder and Hand (DASH) scale to measure the disability of patients with upper limb amputation(s) and to compare these to other upper limb injuries. All 274 patients over the age of 18 years presenting to Prince Henry Hospital in Sydney over a 4-year time frame were given the DASH assessment tool and asked to complete it under supervision of the Occupational Therapist. Patients with brachial plexus injuries, Complex Regional Pain Syndrome and bilateral upper limb amputations demonstrated significantly higher levels of disability to patients with unilateral upper limb amputations. Partial hand amputees reported a higher level of disability than major unilateral upper limb amputees. For the 48 patients who completed pre- and post-treatment assessments, there was a significant improvement in their health status. Further research is required to understand the factors that affect a patient's perceptions of their disability. Perhaps the definitive nature of an amputation and the immediate involvement of highly skilled health professionals serve to assist patients to accept their injury and therefore minimizes the level of disability.

Reinnervating the penis in spina bifida patients in the United States: ilioinguinal-to-dorsal-penile neurorrhaphy in two cases.

PubMed

Jacobs, Micah A; Avellino, Anthony M; Shurtleff, David; Lendvay, Thomas S

2013-10-01

Penile sensation is absent in some patients with myelomeningocele owing to the dysfunction of the pudendal nerve. Here, we describe the introduction of penile sensation via ilioinguinal-to-dorsal-penile neurorrhaphy in two patients with penile anesthesia due to neural tube defects. To establish penile sensation via ilioinguinal-to-dorsal-penile-nerve neurorrhaphy. A 20-year-old and a 35-year-old male with L5/S1 myelomeningocele were both highly functioning and ambulatory, with intact ilioinguinal nerve distribution sensation but anesthesia of the penis and glans. They were sexually active and able to ejaculate antegrade. Both had high International Index of Erectile Function scores for confidence to achieve erection sufficient for intercourse. An incision was made from anterior superior iliac crest to the glans penis to expose the inguinal canal and ilioinguinal nerve. The ilioinguinal and dorsal penile nerve were transected and anastomosed. The anastomotic site was then wrapped in a hemostatic agent and a drain was left in place. For penile rehabilitation, both patients were instructed to stimulate the penis while looking at the genitalia to encourage redistribution of perceived sensation. Presence of erogenous penile sensation was tested by neurologic examination and patient feedback, and patients completed sexual health questionnaires. Both patients reported paresthesias of the groin with penile stimulation 1 month after surgery. Both patients are now 24 months postoperative and have erogenous sensation on the ipsilateral glans and shaft during intercourse. Neither patient has difficulty achieving or maintaining erections. We present two patients with dorsal penile reinnervation via the ilioinguinal nerve. Although nerve reinnervation has been used in urological procedures, this is the first description of an attempt to resupply penile sensation via the dorsal penile nerve in the United States with a minimum of 18 months follow-up. Early follow-up suggests

Elite long jumpers with below the knee prostheses approach the board slower, but take-off more effectively than non-amputee athletes.

PubMed

Willwacher, Steffen; Funken, Johannes; Heinrich, Kai; Müller, Ralf; Hobara, Hiroaki; Grabowski, Alena M; Brüggemann, Gert-Peter; Potthast, Wolfgang

2017-11-22

The use of technological aids to improve sport performance ('techno doping') and inclusion of Paralympic athletes in Olympic events are matters of ongoing debate. Recently, a long jumper with a below the knee amputation (BKA) achieved jump distances similar to world-class athletes without amputations, using a carbon fibre running-specific prosthesis (RSP). We show that athletes with BKA utilize a different, more effective take-off technique in the long jump, which provided the best athlete with BKA a performance advantage of at least 0.13 m compared to non-amputee athletes. A maximum speed constraint imposed by the use of RSPs would indicate a performance disadvantage for the long jump. We found slower maximum sprinting speeds in athletes with BKA, but did not find a difference in the overall vertical force from both legs of athletes with BKA compared to non-amputees. Slower speeds might originate from intrinsically lower sprinting abilities of athletes with BKA or from more complex adaptions in sprinting mechanics due to the biomechanical and morphological differences induced by RSPs. Our results suggest that due to different movement strategies, athletes with and without BKA should likely compete in separate categories for the long jump.

Recommended number of strides for automatic assessment of gait symmetry and regularity in above-knee amputees by means of accelerometry and autocorrelation analysis

PubMed Central

2012-01-01

Background Symmetry and regularity of gait are essential outcomes of gait retraining programs, especially in lower-limb amputees. This study aims presenting an algorithm to automatically compute symmetry and regularity indices, and assessing the minimum number of strides for appropriate evaluation of gait symmetry and regularity through autocorrelation of acceleration signals. Methods Ten transfemoral amputees (AMP) and ten control subjects (CTRL) were studied. Subjects wore an accelerometer and were asked to walk for 70 m at their natural speed (twice). Reference values of step and stride regularity indices (Ad1 and Ad2) were obtained by autocorrelation analysis of the vertical and antero-posterior acceleration signals, excluding initial and final strides. The Ad1 and Ad2 coefficients were then computed at different stages by analyzing increasing portions of the signals (considering both the signals cleaned by initial and final strides, and the whole signals). At each stage, the difference between Ad1 and Ad2 values and the corresponding reference values were compared with the minimum detectable difference, MDD, of the index. If that difference was less than MDD, it was assumed that the portion of signal used in the analysis was of sufficient length to allow reliable estimation of the autocorrelation coefficient. Results All Ad1 and Ad2 indices were lower in AMP than in CTRL (P < 0.0001). Excluding initial and final strides from the analysis, the minimum number of strides needed for reliable computation of step symmetry and stride regularity was about 2.2 and 3.5, respectively. Analyzing the whole signals, the minimum number of strides increased to about 15 and 20, respectively. Conclusions Without the need to identify and eliminate the phases of gait initiation and termination, twenty strides can provide a reasonable amount of information to reliably estimate gait regularity in transfemoral amputees. PMID:22316184

Recurrent laryngeal nerve reinnervation in children: Acoustic and endoscopic characteristics pre-intervention and post-intervention. A comparison of treatment options.

PubMed

Zur, Karen B; Carroll, Linda M

2015-12-01

To establish the benefit of ansa cervicalis-recurrent laryngeal nerve reinnervation (ANSA-RLN) for the management of dysphonia secondary to unilateral vocal cord paralysis (UVCP) in children. Children treated with ANSA-RLN for the management of dysphonia secondary to unilateral vocal fold immobility will have superior acoustic, perceptual, and stroboscopic outcomes compared to injection laryngoplasty and observation. Retrospective case-series chart review. Laryngeal, perceptual, and acoustic analysis of dysphonia was performed in 33 children (age 2-16 years) diagnosed with UVCP. Comparison of pre-post function for treatment groups (no treatment, injection laryngoplasty, ANSA-RLN) with additional comparison between gestational ages, age at initial evaluation, and gender were examined. Perceptual measures included Pediatric Voice Handicap Index (pVHI) and Grade, Roughness, Breathiness, Asthenia, Strain (GBRAS) perceptual rating. Objective measures included semitone (ST) range, jitter%, shimmer%, noise-to-harmonic ratio, voicing, and maximum phonation time. Post-treatment, pVHI, jitter%, and ST were significantly improved for ANSA-RLN subjects compared to injection subjects. Improved function (laryngeal diadochokinesis, pVHI, GRBAS, and/or acoustic) was observed in all ANSA-RLN subjects who had vocal fold paralysis as the only laryngeal diagnosis. This study presents one of the largest studies of pediatric vocal fold paralysis diagnosis and treatment. The study looks at the spectrum of function in patients with UVCP and looks at the outcomes of options: no treatment, injection laryngoplasty, and ANSA-RLN. Although surgical outcomes vary, both injection laryngoplasty and ANSA-RLN show benefit in laryngeal function, voice stability, voice capacity, perceptual rating, and pVHI scores. Both injection laryngoplasty and ANSA-RLN showed improvements post-treatment, and should be considered for management of pediatric UVCP. However, the ANSA-RLN group showed better and longer

Multisession, noninvasive closed-loop neuroprosthetic control of grasping by upper limb amputees.

PubMed

Agashe, H A; Paek, A Y; Contreras-Vidal, J L

2016-01-01

Upper limb amputation results in a severe reduction in the quality of life of affected individuals due to their inability to easily perform activities of daily living. Brain-machine interfaces (BMIs) that translate grasping intent from the brain's neural activity into prosthetic control may increase the level of natural control currently available in myoelectric prostheses. Current BMI techniques demonstrate accurate arm position and single degree-of-freedom grasp control but are invasive and require daily recalibration. In this study we tested if transradial amputees (A1 and A2) could control grasp preshaping in a prosthetic device using a noninvasive electroencephalography (EEG)-based closed-loop BMI system. Participants attempted to grasp presented objects by controlling two grasping synergies, in 12 sessions performed over 5 weeks. Prior to closed-loop control, the first six sessions included a decoder calibration phase using action observation by the participants; thereafter, the decoder was fixed to examine neuroprosthetic performance in the absence of decoder recalibration. Ability of participants to control the prosthetic was measured by the success rate of grasping; ie, the percentage of trials within a session in which presented objects were successfully grasped. Participant A1 maintained a steady success rate (63±3%) across sessions (significantly above chance [41±5%] for 11 sessions). Participant A2, who was under the influence of pharmacological treatment for depression, hormone imbalance, pain management (for phantom pain as well as shoulder joint inflammation), and drug dependence, achieved a success rate of 32±2% across sessions (significantly above chance [27±5%] in only two sessions). EEG signal quality was stable across sessions, but the decoders created during the first six sessions showed variation, indicating EEG features relevant to decoding at a smaller timescale (100ms) may not be stable. Overall, our results show that (a) an EEG

Erotic target location errors: an underappreciated paraphilic dimension.

PubMed

Lawrence, Anne A

2009-01-01

Based on studies of heterosexual male fetishists, transvestites, and transsexuals, Blanchard (1991) proposed the existence of a hitherto unrecognized paraphilic dimension, erotic target location errors (ETLEs), involving the erroneous location of erotic targets in the environment. ETLEs can involve preferential attention to a peripheral or inessential part of an erotic target, manifesting as fetishism, or mislocation of an erotic target in one's own body, manifesting as the desire to impersonate or become a facsimile of the erotic target (e.g., transvestism or transsexualism). Despite its potential clinical and heuristic value, the concept that ETLEs define a paraphilic dimension is underappreciated. This review summarizes the studies leading to the concept of ETLEs and describes how ETLEs are believed to manifest in men whose preferred erotic targets are women, children, men, amputees, plush animals, and real animals. This review also describes ETLEs in women; discusses possible etiologies of ETLEs; considers the implications of the ETLE concept for psychoanalytic theories of transvestism and male-to-female transsexualism, as well as for the forthcoming revision of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; suggests reasons why the concept of ETLEs has been underappreciated; and describes what might result if the concept were more widely appreciated.

A comprehensive musculoskeletal and peripheral nervous system assessment of war-related bilateral upper extremity amputees.

PubMed

Allami, Mostafa; Mousavi, Batool; Masoumi, Mehdi; Modirian, Ehsan; Shojaei, Hadi; Mirsalimi, Fatemeh; Hosseini, Maryam; Pirouzi, Pirouz

2016-01-01

Upper limb amputations are one of the unpleasant war injuries that armed forces are exposed to frequently. The present study aimed to assess the musculoskeletal and peripheral nervous systems in Iraq-Iran war veterans with bilateral upper extremity amputation. The study consisted of taking a history and clinical examinations including demographic data, presence and location of pain, level of amputation, passive and active ranges of movement of the joints across the upper and lower extremities and spine, manual palpation, neurological examination, blood circulation pulses and issues related to a prosthetic limb. In this study, 103 Iranian bilateral upper extremity amputees (206 amputations) from the Iran-Iraq war were evaluated, and a detailed questionnaire was also administered. The most common level of amputation was the finger or wrist level (108, 52.4 %). Based on clinical examination, we found high frequencies of limited active and passive joint range of movement across the scapula, shoulder, elbow, wrist and metacarpophalangeal, interphalangeal and thumb joints. Based on muscle strength testing, we found varying degrees of weakness across the upper limbs. Musculoskeletal disorders included epicondylitis (65, 31.6 %), rotator cuff injury (24, 11.7 %), bicipital tendonitis (69, 33.5 %), shoulder drop (42, 20.4 %) and muscle atrophy (19, 9.2 %). Peripheral nerve disorders included carpal tunnel syndrome in 13 (6.3 %) and unilateral brachial plexus injury in 1 (1 %). Fifty-three (51.5 %) were diagnosed with facet joint syndrome at the level of the cervical spine (the most frequent site). Using a prosthesis was reported by 65 (63.1 %), both left and right sides. The back was the most common site of pain (71.8 %). The high prevalence of neuro-musculoskeletal disorders among bilateral upper extremity amputees indicates that they need regular rehabilitation care.

Post-amputation pain is associated with the recall of an impaired body representation in dreams-results from a nation-wide survey on limb amputees.

PubMed

Bekrater-Bodmann, Robin; Schredl, Michael; Diers, Martin; Reinhard, Iris; Foell, Jens; Trojan, Jörg; Fuchs, Xaver; Flor, Herta

2015-01-01

The experience of post-amputation pain such as phantom limb pain (PLP) and residual limb pain (RLP), is a common consequence of limb amputation, and its presence has negative effects on a person's well-being. The continuity hypothesis of dreams suggests that the presence of such aversive experiences in the waking state should be reflected in dream content, with the recalled body representation reflecting a cognitive proxy of negative impact. In the present study, we epidemiologically assessed the presence of post-amputation pain and other amputation-related information as well as recalled body representation in dreams in a sample of 3,234 unilateral limb amputees. Data on the site and time of amputation, residual limb length, prosthesis use, lifetime prevalence of mental disorders, presence of post-amputation pain, and presence of non-painful phantom phenomena were included in logistic regression analyses using recalled body representation in dreams (impaired, intact, no memory) as dependent variable. The effects of age, sex, and frequency of dream recall were controlled for. About 22% of the subjects indicated that they were not able to remember their body representation in dreams, another 24% of the amputees recalled themselves as always intact, and only a minority of less than 3% recalled themselves as always impaired. Almost 35% of the amputees dreamed of themselves in a mixed fashion. We found that lower-limb amputation as well as the presence of PLP and RLP was positively associated with the recall of an impaired body representation in dreams. The presence of non-painful phantom phenomena, however, had no influence. These results complement previous findings and indicate complex interactions of physical body appearance and mental body representation, probably modulated by distress in the waking state. The findings are discussed against the background of alterations in cognitive processes after amputation and hypotheses suggesting an innate body model.

Post-Amputation Pain Is Associated with the Recall of an Impaired Body Representation in Dreams—Results from a Nation-Wide Survey on Limb Amputees

PubMed Central

Bekrater-Bodmann, Robin; Schredl, Michael; Diers, Martin; Reinhard, Iris; Foell, Jens; Trojan, Jörg; Fuchs, Xaver; Flor, Herta

2015-01-01

The experience of post-amputation pain such as phantom limb pain (PLP) and residual limb pain (RLP), is a common consequence of limb amputation, and its presence has negative effects on a person’s well-being. The continuity hypothesis of dreams suggests that the presence of such aversive experiences in the waking state should be reflected in dream content, with the recalled body representation reflecting a cognitive proxy of negative impact. In the present study, we epidemiologically assessed the presence of post-amputation pain and other amputation-related information as well as recalled body representation in dreams in a sample of 3,234 unilateral limb amputees. Data on the site and time of amputation, residual limb length, prosthesis use, lifetime prevalence of mental disorders, presence of post-amputation pain, and presence of non-painful phantom phenomena were included in logistic regression analyses using recalled body representation in dreams (impaired, intact, no memory) as dependent variable. The effects of age, sex, and frequency of dream recall were controlled for. About 22% of the subjects indicated that they were not able to remember their body representation in dreams, another 24% of the amputees recalled themselves as always intact, and only a minority of less than 3% recalled themselves as always impaired. Almost 35% of the amputees dreamed of themselves in a mixed fashion. We found that lower-limb amputation as well as the presence of PLP and RLP was positively associated with the recall of an impaired body representation in dreams. The presence of non-painful phantom phenomena, however, had no influence. These results complement previous findings and indicate complex interactions of physical body appearance and mental body representation, probably modulated by distress in the waking state. The findings are discussed against the background of alterations in cognitive processes after amputation and hypotheses suggesting an innate body model. PMID

The effects of prosthetic foot stiffness on transtibial amputee walking mechanics and balance control during turning.

PubMed

Shell, Courtney E; Segal, Ava D; Klute, Glenn K; Neptune, Richard R

2017-11-01

Little evidence exists regarding how prosthesis design characteristics affect performance in tasks that challenge mediolateral balance such as turning. This study assesses the influence of prosthetic foot stiffness on amputee walking mechanics and balance control during a continuous turning task. Three-dimensional kinematic and kinetic data were collected from eight unilateral transtibial amputees as they walked overground at self-selected speed clockwise and counterclockwise around a 1-meter circle and along a straight line. Subjects performed the walking tasks wearing three different ankle-foot prostheses that spanned a range of sagittal- and coronal-plane stiffness levels. A decrease in stiffness increased residual ankle dorsiflexion (10-13°), caused smaller adaptations (<5°) in proximal joint angles, decreased residual and increased intact limb body support, increased residual limb propulsion and increased intact limb braking for all tasks. While changes in sagittal-plane joint work due to decreased stiffness were generally consistent across tasks, effects on coronal-plane hip work were task-dependent. When the residual limb was on the inside of the turn and during straight-line walking, coronal-plane hip work increased and coronal-plane peak-to-peak range of whole-body angular momentum decreased with decreased stiffness. Changes in sagittal-plane kinematics and kinetics were similar to those previously observed in straight-line walking. Mediolateral balance improved with decreased stiffness, but adaptations in coronal-plane angles, work and ground reaction force impulses were less systematic than those in sagittal-plane measures. Effects of stiffness varied with the residual limb inside versus outside the turn, which suggests that actively adjusting stiffness to turn direction may be beneficial. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prosthesis Control with an Implantable Multichannel Wireless Electromyography System for High-Level Amputees: A Large-Animal Study.

PubMed

Bergmeister, Konstantin D; Hader, Marie; Lewis, Soeren; Russold, Michael-Friedrich; Schiestl, Martina; Manzano-Szalai, Krisztina; Roche, Aidan D; Salminger, Stefan; Dietl, Hans; Aszmann, Oskar C

2016-01-01

Myoelectric prostheses lack a strong human-machine interface, leading to high abandonment rates in upper limb amputees. Implantable wireless electromyography systems improve control by recording signals directly from muscle, compared with surface electromyography. These devices do not exist for high amputation levels. In this article, the authors present an implantable wireless electromyography system for these scenarios tested in Merino sheep for 4 months. In a pilot trial, the electrodes were implanted in the hind limbs of 24 Sprague-Dawley rats. After 8 or 12 weeks, impedance and histocompatibility were assessed. In the main trial, the system was tested in four Merino sheep for 4 months. Impedance of the electrodes was analyzed in two animals. Electromyographic data were analyzed in two freely moving animals repeatedly during forward and backward gait. Device implantation was successful in all 28 animals. Histologic evaluation showed a tight encapsulation after 8 weeks of 78.2 ± 26.5 µm subcutaneously and 92.9 ± 31.3 µm on the muscular side. Electromyographic recordings show a distinct activation pattern of the triceps, brachialis, and latissimus dorsi muscles, with a low signal-to-noise ratio, representing specific patterns of agonist and antagonist activation. Average electrode impedance decreased over the whole frequency range, indicating an improved electrode-tissue interface during the implantation. All measurements taken over the 4 months of observation used identical settings and showed similar recordings despite changing environmental factors. This study shows the implantation of this electromyography device as a promising alternative to surface electromyography, providing a potentially powerful wireless interface for high-level amputees.

Long-term follow-up of unilateral transfemoral amputees from the Vietnam war.

PubMed

Dougherty, Paul J

2003-04-01

Despite their frequency, few reports exist concerning the initial and long-term consequences of battle-incurred unilateral transfemoral amputations. A retrospective cohort design was used to measure the long-term health of transfemoral battle amputees treated at a single hospital during the Vietnam War. Data collection consisted of medical record abstraction and a follow-up questionnaire that included the SF-36 Health Survey. Forty-six patients responded to the survey an average of 28 years after injury. Compared with the controls, patient responses to the SF-36 were significantly (p < 0.01) less in all categories except Mental Health and Vitality. Forty-three (93.5%) are or have been married. Forty-one (89.1%) are or have been employed an average of 20.1 years. Forty patients (87%) wore a prosthesis an average of 13.5 h/day. Although the patients do relatively well with employment and marriage stability, the low SF-36 scores suggest a significant disability.

The effects of graded motor imagery and its components on phantom limb pain and disability in upper and lower limb amputees: a systematic review protocol.

PubMed

Limakatso, Katleho; Corten, Lieselotte; Parker, Romy

2016-09-01

Phantom limb pain (PLP) is characterized by the anatomical shifting of neighbouring somatosensory and motor areas into a deafferented cortical area of the brain contralateral to the amputated limb. It has been shown that maladaptive neuroplasticity is positively correlated to the perception of PLP in amputees. Recent studies support the use of graded motor imagery (GMI) and its component to alleviate the severity of PLP and disability. However, there is insufficient collective empirical evidence exploring the effectiveness of these treatment modalities in amputees with PLP. This systematic review will therefore explore the effects of GMI and its individual components on PLP and disability in upper and lower limb amputees. We will utilize a customized search strategy to search PubMed, Cochrane Central register of Controlled Trials, MEDLINE, Embase, PsycINFO, PEDro, Scopus, CINAHL, LILACS, DARE, Africa-Wide Information and Web of Science. We will also look at clinicaltrials.gov ( http://www.clinicaltrials.gov/ ), Pactr.gov ( http://www.pactr.org/ ) and EU Clinical trials register ( https://www.clinicaltrialsregister.eu/ ) for ongoing research. Two independent reviewers will screen articles for methodological validity. Thereafter, data from included studies will be extracted by two independent reviewers through a customized pre-set data extraction sheet. Studies with a comparable intervention and outcome measure will be pooled for meta-analysis. Studies with high heterogeneity will be analysed through random effects model. A narrative data analysis will be considered where there is insufficient data to perform a meta-analysis. Several studies investigating the effectiveness of GMI and its different components on PLP have drawn contrasting conclusions regarding the efficacy and applicability of GMI in clinical practice. This systematic review will therefore gather and critically appraise all relevant data, to generate a substantial conclusion and recommendations for

Estimation of distal arm joint angles from EMG and shoulder orientation for transhumeral prostheses.

PubMed

Akhtar, Aadeel; Aghasadeghi, Navid; Hargrove, Levi; Bretl, Timothy

2017-08-01

In this paper, we quantify the extent to which shoulder orientation, upper-arm electromyography (EMG), and forearm EMG are predictors of distal arm joint angles during reaching in eight subjects without disability as well as three subjects with a unilateral transhumeral amputation and targeted reinnervation. Prior studies have shown that shoulder orientation and upper-arm EMG, taken separately, are predictors of both elbow flexion/extension and forearm pronation/supination. We show that, for eight subjects without disability, shoulder orientation and upper-arm EMG together are a significantly better predictor of both elbow flexion/extension during unilateral (R 2 =0.72) and mirrored bilateral (R 2 =0.72) reaches and of forearm pronation/supination during unilateral (R 2 =0.77) and mirrored bilateral (R 2 =0.70) reaches. We also show that adding forearm EMG further improves the prediction of forearm pronation/supination during unilateral (R 2 =0.82) and mirrored bilateral (R 2 =0.75) reaches. In principle, these results provide the basis for choosing inputs for control of transhumeral prostheses, both by subjects with targeted motor reinnervation (when forearm EMG is available) and by subjects without target motor reinnervation (when forearm EMG is not available). In particular, we confirm that shoulder orientation and upper-arm EMG together best predict elbow flexion/extension (R 2 =0.72) for three subjects with unilateral transhumeral amputations and targeted motor reinnervation. However, shoulder orientation alone best predicts forearm pronation/supination (R 2 =0.88) for these subjects, a contradictory result that merits further study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Providing time-discrete gait information by wearable feedback apparatus for lower-limb amputees: usability and functional validation.

PubMed

Crea, Simona; Cipriani, Christian; Donati, Marco; Carrozza, Maria Chiara; Vitiello, Nicola

2015-03-01

Here we describe a novel wearable feedback apparatus for lower-limb amputees. The system is based on three modules: a pressure-sensitive insole for the measurement of the plantar pressure distribution under the prosthetic foot during gait, a computing unit for data processing and gait segmentation, and a set of vibrating elements placed on the thigh skin. The feedback strategy relies on the detection of specific gait-phase transitions of the amputated leg. Vibrating elements are activated in a time-discrete manner, simultaneously with the occurrence of the detected gait-phase transitions. Usability and effectiveness of the apparatus were successfully assessed through an experimental validation involving ten healthy volunteers.

Modulation of the Neuregulin 1/ErbB system after skeletal muscle denervation and reinnervation.

PubMed

Morano, Michela; Ronchi, Giulia; Nicolò, Valentina; Fornasari, Benedetta Elena; Crosio, Alessandro; Perroteau, Isabelle; Geuna, Stefano; Gambarotta, Giovanna; Raimondo, Stefania

2018-03-22

Neuregulin 1 (NRG1) is a growth factor produced by both peripheral nerves and skeletal muscle. In muscle, it regulates neuromuscular junction gene expression, acetylcholine receptor number, muscle homeostasis and satellite cell survival. NRG1 signalling is mediated by the tyrosine kinase receptors ErbB3 and ErbB4 and their co-receptors ErbB1 and ErbB2. The NRG1/ErbB system is well studied in nerve tissue after injury, but little is known about this system in skeletal muscle after denervation/reinnervation processes. Here, we performed a detailed time-course expression analysis of several NRG1 isoforms and ErbB receptors in the rat superficial digitorum flexor muscle after three types of median nerve injuries of different severities. We found that ErbB receptor expression was correlated with the innervated state of the muscle, with upregulation of ErbB2 clearly associated with the denervation state. Interestingly, the NRG1 isoforms were differently regulated depending on the nerve injury type, leading to the hypothesis that both the NRG1α and NRG1β isoforms play a key role in the muscle reaction to injury. Indeed, in vitro experiments with C2C12 atrophic myotubes revealed that both NRG1α and NRG1β treatment influences the best-known atrophic pathways, suggesting that NRG1 might play an anti-atrophic role.

Comparison of Rectified and Unrectified Sockets for Transtibial Amputees.

PubMed

Engsberg, Jack R; Sprouse, S Wayne; Uhrich, Mary L; Ziegler, Barbara R; Luitjohan, F Daniel

2008-01-01

The current method for fabricating prosthetic sockets is to modify a positive mold to account for the non-homogeneity of the residual limb to tolerate load (i.e., rectified socket). We tested unrectified sockets by retaining the shape of the residual limb, except for a distal end pad, using an alginate gel process instead of casting. This investigation compared rectified and unrectified sockets. Forty-three adults with unilateral transtibial amputations were tested after randomly wearing both rectified and unrectified sockets for at least 4 weeks. Testing included a gait analysis, energy expenditure and Prosthesis Evaluation Questionnaire (PEQ). Results indicated no differences between sockets for gait speed and timing, gait kinematics and kinetics, and gait energy expenditure. There were also no differences in the Prosthetic Evaluation Questionnaire and 16 subjects selected the rectified socket, 25 selected the unrectified socket, and 2 subjects selected to use both sockets as their exit socket. Results seemed to indicate that more than one paradigm exists for shaping prosthetic sockets, and this paradigm may be helpful in understanding the mechanisms of socket fit. The alginate gel fabrication method was simpler than the traditional method. The method could be helpful in other countries where prosthetic care is lacking, may be helpful with new amputees, and may be helpful in typical clinics to reduce costs and free the prosthetist to focus more time on patient needs.

Comparison of Rectified and Unrectified Sockets for Transtibial Amputees

PubMed Central

Engsberg, Jack R.; Sprouse, S. Wayne; Uhrich, Mary L.; Ziegler, Barbara R.; Luitjohan, F. Daniel

2008-01-01

The current method for fabricating prosthetic sockets is to modify a positive mold to account for the non-homogeneity of the residual limb to tolerate load (i.e., rectified socket). We tested unrectified sockets by retaining the shape of the residual limb, except for a distal end pad, using an alginate gel process instead of casting. This investigation compared rectified and unrectified sockets. Forty-three adults with unilateral transtibial amputations were tested after randomly wearing both rectified and unrectified sockets for at least 4 weeks. Testing included a gait analysis, energy expenditure and Prosthesis Evaluation Questionnaire (PEQ). Results indicated no differences between sockets for gait speed and timing, gait kinematics and kinetics, and gait energy expenditure. There were also no differences in the Prosthetic Evaluation Questionnaire and 16 subjects selected the rectified socket, 25 selected the unrectified socket, and 2 subjects selected to use both sockets as their exit socket. Results seemed to indicate that more than one paradigm exists for shaping prosthetic sockets, and this paradigm may be helpful in understanding the mechanisms of socket fit. The alginate gel fabrication method was simpler than the traditional method. The method could be helpful in other countries where prosthetic care is lacking, may be helpful with new amputees, and may be helpful in typical clinics to reduce costs and free the prosthetist to focus more time on patient needs. PMID:18776945

Toward attenuating the impact of arm positions on electromyography pattern-recognition based motion classification in transradial amputees

PubMed Central

2012-01-01

Background Electromyography (EMG) pattern-recognition based control strategies for multifunctional myoelectric prosthesis systems have been studied commonly in a controlled laboratory setting. Before these myoelectric prosthesis systems are clinically viable, it will be necessary to assess the effect of some disparities between the ideal laboratory setting and practical use on the control performance. One important obstacle is the impact of arm position variation that causes the changes of EMG pattern when performing identical motions in different arm positions. This study aimed to investigate the impacts of arm position variation on EMG pattern-recognition based motion classification in upper-limb amputees and the solutions for reducing these impacts. Methods With five unilateral transradial (TR) amputees, the EMG signals and tri-axial accelerometer mechanomyography (ACC-MMG) signals were simultaneously collected from both amputated and intact arms when performing six classes of arm and hand movements in each of five arm positions that were considered in the study. The effect of the arm position changes was estimated in terms of motion classification error and compared between amputated and intact arms. Then the performance of three proposed methods in attenuating the impact of arm positions was evaluated. Results With EMG signals, the average intra-position and inter-position classification errors across all five arm positions and five subjects were around 7.3% and 29.9% from amputated arms, respectively, about 1.0% and 10% low in comparison with those from intact arms. While ACC-MMG signals could yield a similar intra-position classification error (9.9%) as EMG, they had much higher inter-position classification error with an average value of 81.1% over the arm positions and the subjects. When the EMG data from all five arm positions were involved in the training set, the average classification error reached a value of around 10.8% for amputated arms. Using a

The influence of lower limb amputation level on the approach in the amputee long jump.

PubMed

Nolan, Lee; Lees, Adrian

2007-02-15

In this study, we investigated the adjustments to posture, kinematic and temporal characteristics of performance made by lower limb amputees during the last few strides in preparation for long jump take-off. Six male unilateral trans-femoral and seven male unilateral trans-tibial amputees competing in a World Championships final were filmed in the sagittal plane using a 100-Hz digital video camera positioned so that the last three strides to take-off were visible. After digitizing using a nine-segment model, a range of kinematic variables were computed to define technique characteristics. Both the trans-femoral and trans-tibial athletes appeared to achieve their reduction in centre of mass during the flight phase between strides, and did so mainly by extending the flight time by increasing stride length, achieved by a greater flexion of the hip joint of the touch-down leg. The trans-tibial athletes appeared to adopt a technique similar to that previously reported for able-bodied athletes. They lowered their centre of mass most on their second last stride (-1.6% of body height compared with -1.4% on the last stride) and used a flexed knee at take-off on the last stride, but they were less able to control their downward velocity at touch-down (-0.4 m x s(-1)). Both this and their restricted approach speed (8.9 m x s(-1) at touch-down), rather than technique limitations, influenced their jump performance. The trans-femoral athletes lowered their centre of mass most on the last stride (-2.3% of body height compared with -1.6% on the second last stride) and, as they were unable to flex their prosthetic knee sufficiently, achieved this by abducting their prosthetic leg during the support phase, which led to a large downward velocity at touch-down (-0.6 m x s(-1)). This, combined with their slower approach velocity (7.1 m x s(-1) at touch-down), restricted their performance.

Long-term follow-up study of bilateral above-the-knee amputees from the Vietnam War.

PubMed

Dougherty, P J

1999-10-01

Because caring for patients who have combat-related amputations is a discontinuous practice, military surgeons must relearn treatment techniques during each conflict. The purpose of the present long-term study (average duration of follow-up, 27.5 years) was to document the status of patients who had sustained a bilateral above-the-knee amputation in Vietnam and had been managed by the only separate amputee service in the United States Army. A review of the records of 484 battle amputees identified thirty individuals (6 percent) who had a bilateral above-the-knee amputation. Twenty-six (87 percent) of the thirty patients had been injured by a land mine or a booby trap. Fifty-three (88 percent) of the sixty limbs were amputated because of trauma, and the other seven (12 percent) were amputated secondarily because of infection. Data regarding education, employment, marriage and family life, prosthetic use, and psychological care were collected by mail or telephone for twenty-three (85 percent) of the twenty-seven surviving patients. Respondents also completed the Short Form-36 (SF-36) Health Survey. At the time of the study, five (22 percent) of the twenty-three respondents used prostheses for walking; the devices were used for an average of 7.7 hours per day. Sixteen respondents (70 percent) were or had been employed outside of the home since the time of discharge. The physical functioning score on the SF-36 questionnaire was significantly lower for the study group than it was for a group of age and gender-matched controls (p < 0.001; Student two-tailed t test). With the numbers available, no significant differences could be detected between the groups with regard to physical role functioning (p = 0.377), bodily pain (p = 0.603), general health (p = 0.407), vitality (p = 0.949), social functioning (p = 0.460), emotional role functioning (p = 0.029), or mental health (p = 0.102). The patients in the present study have led relatively normal, productive lives within the

A questionnaire survey of the effect of different interface types on patient satisfaction and perceived problems among trans-tibial amputees.

PubMed

Van de Weg, F B; Van der Windt, D A W M

2005-12-01

The objectives were to investigate the effect of three different interface types on consumer satisfaction and perceived problems among trans-tibial amputees in the Netherlands. A postal questionnaire (based on the Prosthesis Evaluation Questionnaire) was sent to 353 patients. Responders were classified in three groups of interface types: polyethylene foam (PEF) inserts, silicone liners (SIL), and polyurethane liners (PUL). Differences concerning satisfaction and problems between interface types were computed and adjusted for potential confounding by age, gender, reason for amputation and time since first prosthesis. A total of 220 patients responded (62%). Patients wearing liners reported a significantly poorer durability and higher maintenance time compared with patients using PEF inserts. Sum-scores for satisfaction or problems did not show any significant differences between groups. Analysis of individual items showed a significant difference only for satisfaction with sitting and with walking on uneven terrain in favour of PEF inserts. In contrast to most studies, interface type was included as a possible determinant of customer use, satisfaction, and perceived problems. The perceived differences between the three suspension types are to a large extent small and non-significant. The findings do not support liner prescription as a matter of course for all trans-tibial amputees. A careful analysis of patients' preferences should be made to determine the best course of action. Further studies, preferably prospective, need to be conducted to determine which systems are most comfortable and offer least complaints.

Performance enhancement of epoxy based sandwich composites using multiwalled carbon nanotubes for the application of sockets in trans-femoral amputees.

PubMed

Arun, S; Kanagaraj, S

2016-06-01

A socket plays a vital role in giving the comfort to the amputees. However, the accumulation of heat inside the socket and its weight led to increase their metabolic cost. Hence, an attempt was made to increase the performance of the epoxy based sandwich composites to be used for the socket by reinforcing multiwalled carbon nanotubes (MWCNT), which was varied from 0.1 to 0.5wt%. It was homogeneously dispersed in epoxy to obtain the desired properties, where the enhancement of thermal conductivity, compressive strength and modulus of epoxy was observed to be 76.7%, 62.6% and 20.2%, respectively at 0.3wt% of MWCNT concentration beyond which the mechanical properties were found to be decreased. Hence, the epoxy, E-glass plain fabric, 2-10 layers of stockinet and 0.3wt% of MWCNT were used to prepare the sandwich composites. The flexural strength and thermal conductivity of 0.3wt% of MWCNT reinforced sandwich composites were found to be improved by 11.38±1.5% and 29.8±1.3% for the 4-10 layers and up to 10 layers of stockinet, respectively compared to unreinforced sandwich composites, which helped to reduce the weight of the socket and decrease the heat accumulation inside the socket. Thus, it is suggested to be explored for the application of socket in trans-femoral amputees to increase their comfort level by decreasing the metabolic cost. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees.

PubMed

Theeven, Patrick; Hemmen, Bea; Rings, Frans; Meys, Guido; Brink, Peter; Smeets, Rob; Seelen, Henk

2011-10-01

To assess the effects of using a microprocessor-controlled prosthetic knee joint on the functional performance of activities of daily living in persons with an above-knee leg amputation. To assess the effects of using a microprocessor-controlled prosthetic knee joint on the functional performance of activities of daily living in persons with an above-knee leg amputation. Randomised cross-over trial. Forty-one persons with unilateral above-knee or knee disarticulation limb loss, classified as Medicare Functional Classification Level-2 (MFCL-2). Participants were measured in 3 conditions, i.e. using a mechanically controlled knee joint and two types of microprocessor-controlled prosthetic knee joints. Functional performance level was assessed using a test in which participants performed 17 simulated activities of daily living (Assessment of Daily Activity Performance in Transfemoral amputees test). Performance time was measured and self-perceived level of difficulty was scored on a visual analogue scale for each activity. High levels of within-group variability in functional performance obscured detection of any effects of using a microprocessor-controlled prosthetic knee joint. Data analysis after stratification of the participants into 3 subgroups, i.e. participants with a "low", "intermediate" and "high" functional mobility level, showed that the two higher functional subgroups performed significantly faster using microprocessor-controlled prosthetic knee joints. MFCL-2 amputees constitute a heterogeneous patient group with large variation in functional performance levels. A substantial part of this group seems to benefit from using a microprocessor-controlled prosthetic knee joint when performing activities of daily living.

Brief post-surgical electrical stimulation accelerates axon regeneration and muscle reinnervation without affecting the functional measures in carpal tunnel syndrome patients.

PubMed

Gordon, Tessa; Amirjani, Nasim; Edwards, David C; Chan, K Ming

2010-05-01

Electrical stimulation (ES) of injured peripheral nerves accelerates axonal regeneration in laboratory animals. However, clinical applicability of this intervention has never been investigated in human subjects. The aim of this pilot study was to determine the effect of ES on axonal regeneration after surgery in patients with median nerve compression in the carpal tunnel causing marked motor axonal loss. A randomized control trial was conducted to provide proof of principle for ES-induced acceleration of axon regeneration in human patients. Carpel tunnel release surgery (CTRS) was performed and in the stimulation group of patients, stainless steel electrode wires placed alongside the median nerve proximal to the surgical decompression site for immediate 1 h 20 Hz bipolar ES. Subjects were followed for a year at regular intervals. Axonal regeneration was quantified using motor unit number estimation (MUNE) and sensory and motor nerve conduction studies. Purdue Pegboard Test, Semmes Weinstein Monofilaments, and Levine's Self-Assessment Questionnaire were used to assess functional recovery. The stimulation group had significant axonal regeneration 6-8 months after the CTRS when the MUNE increased to 290+/-140 (mean+/-SD) motor units (MU) from 150+/-62 MU at baseline (p<0.05). In comparison, MUNE did not significantly improve in the control group (p>0.2). Terminal motor latency significantly accelerated in the stimulation group but not the control group (p>0.1). Sensory nerve conduction values significantly improved in the stimulation group earlier than the controls. Other outcome measures showed a significant improvement in both patient groups. We conclude that brief low frequency ES accelerates axonal regeneration and target reinnervation in humans. Copyright 2009 Elsevier Inc. All rights reserved.

Use of prostheses and footwear in 110 inner-city partial-foot amputees.

PubMed

Sobel, E; Japour, C J; Giorgini, R J; Levitz, S J; Richardson, H L

2001-01-01

The number of partial-foot amputations performed is increasing, and many recommendations have been made regarding the use of prostheses and footwear designed to prevent higher-level amputations in this population. The present study investigated the use of prostheses and shoe inserts and the types of footwear worn by partial-foot amputees in the inner city to determine whether previous recommendations are being followed as well as whether new prosthetic styles are being used. The study surveyed 110 patients (73 men and 37 women) with a mean age of 58.6 years (range, 21 to 86 years) with partial-foot amputations of all levels. The results showed that about one-half of all patients wore a shoe-insert orthosis. Although 54% wore some form of special footwear to accommodate and protect the residual foot, no patient in this study wore a shoe with a rocker-bottom sole. Only one patient with a transmetatarsal amputation used a brace and only one patient in the entire study wore a modern cosmetic foot prosthesis.

Microarray Analysis Gene Expression Profiles in Laryngeal Muscle After Recurrent Laryngeal Nerve Injury.

PubMed

Bijangi-Vishehsaraei, Khadijeh; Blum, Kevin; Zhang, Hongji; Safa, Ahmad R; Halum, Stacey L

2016-03-01

The pathophysiology of recurrent laryngeal nerve (RLN) transection injury is rare in that it is characteristically followed by a high degree of spontaneous reinnervation, with reinnervation of the laryngeal adductor complex (AC) preceding that of the abducting posterior cricoarytenoid (PCA) muscle. Here, we aim to elucidate the differentially expressed myogenic factors following RLN injury that may be at least partially responsible for the spontaneous reinnervation. F344 male rats underwent RLN injury (n = 12) or sham surgery (n = 12). One week after RLN injury, larynges were harvested following euthanasia. The mRNA was extracted from PCA and AC muscles bilaterally, and microarray analysis was performed using a full rat genome array. Microarray analysis of denervated AC and PCA muscles demonstrated dramatic differences in gene expression profiles, with 205 individual probes that were differentially expressed between the denervated AC and PCA muscles and only 14 genes with similar expression patterns. The differential expression patterns of the AC and PCA suggest different mechanisms of reinnervation. The PCA showed the gene patterns of Wallerian degeneration, while the AC expressed the gene patterns of reinnervation by adjacent axonal sprouting. This finding may reveal important therapeutic targets applicable to RLN and other peripheral nerve injuries. © The Author(s) 2015.

Exercise intervention for unilateral amputees with low back pain: study protocol for a randomised, controlled trial.

PubMed

Wasser, Joseph G; Herman, Daniel C; Horodyski, MaryBeth; Zaremski, Jason L; Tripp, Brady; Page, Phillip; Vincent, Kevin R; Vincent, Heather K

2017-12-29

Atraumatic lower limb amputation is a life-changing event for approximately 185,000 persons in the United States each year. A unilateral amputation is associated with rapid changes to the musculoskeletal system including leg and back muscle atrophy, strength loss, gait asymmetries, differential mechanical joint loading and leg length discrepancies. Even with high-quality medical care and prostheses, amputees still develop secondary musculoskeletal conditions such as chronic low back pain (LBP). Resistance training interventions that focus on core stabilization, lumbar strength and dynamic stability during loading have strong potential to reduce LBP and address amputation-related changes to the musculoskeletal system. Home-based resistance exercise programs may be attractive to patients to minimize travel and financial burdens. This study will be a single-assessor-blinded, pre-post-test randomised controlled trial involving 40 men and women aged 18-60 years with traumatic, unilateral transtibial amputation. Participants will be randomised to a home-based, resistance exercise group (HBRX) or a wait-list control group (CON). The HBRX will consist of 12 weeks of elastic resistance band and bodyweight training to improve core and lumbopelvic strength. Participants will be monitored via Skype or Facetime on a weekly basis. The primary outcome will be pain severity (11-point Numerical Pain Rating Scale; NRS pain ). Secondary outcomes will include pain impact on quality of life (Medical Outcomes Short Form 36, Oswestry Disability Index and Roland Morris Disability Questionnaire), kinematics and kinetics of walking gait on an instrumented treadmill, muscle morphology (muscle thickness of multifidus, transversus abdominis, internal oblique), maximal muscle strength of key lumbar and core muscles, and daily step count. The study findings will determine whether a HBRX program can decrease pain severity and positively impact several physiological and mechanical factors that

Upper-arm anthropometry: an alternative indicator of nutritional health to body mass index in unilateral lower-extremity amputees?

PubMed

Miller, Michelle; Wong, Wing Ki; Wu, Jing; Cavenett, Sally; Daniels, Lynne; Crotty, Maria

2008-10-01

To evaluate the utility of body mass index (BMI) and corrected-arm-muscle area (CAMA) as measures of nutritional health for lower-limb amputees attending prosthetics clinics. Cross-sectional study. Prosthetics clinic in Australia. Unilateral lower-extremity amputees (N=58; age range, 21-91y; 37 transtibial, 21 transfemoral) attending a regional prosthetics clinic between May and November 2003. Not applicable. Weight (without prosthesis), corrected and uncorrected for the amputated limb was used with height estimated from knee height to calculate corrected BMI (cBMI) and uncorrected BMI (uBMI). CAMA was calculated using the mean of triplicate mid-upper-arm circumference (MUAC) and triceps skinfold thickness (TST) measurements. The Mini Nutritional Assessment (MNA) and Assessment of Quality of Life were administered according to recommended protocols. The Pearson correlation was used to determine the strength and significance of associations between variables, and bivariate regression analyses were performed to determine whether an association existed between the nutritional variables (BMI, CAMA, MNA) and quality of life (QOL). There were no statistically significant differences in the measures of nutritional health according to site (transtibial, transfemoral) of amputation. MUAC, TST, and CAMA all showed moderate to high positive correlations (r range, .541-.782) with both cBMI and uBMI. The strength of the relationship between the MNA and cBMI/uBMI was weaker (r=.383, r=.380, respectively) but remained positive and statistically significant (P=.003). QOL was not associated with cBMI or uBMI but was related to CAMA (beta=-.132; P=.030) and MNA (beta=-.561; P=.017). For persons with unilateral lower-extremity amputation, measurement of upper-arm anthropometry may be a more useful indicator of nutritional health and its consequences than BMI.

The effect of aging on efferent nerve fibers regeneration in mice.

PubMed

Verdú, E; Butí, M; Navarro, X

1995-10-23

This study evaluates the influence of aging on nerve regeneration and reinnervation of target organs in mice aged 2, 6, 9, 12, 18 and 24 months. In animals of each age group the sciatic nerve was subjected to crush, section or section and suture. Reinnervation of plantar muscles and sweat glands (SG) was evaluated over three months after operation by functional methods. Reappearance of SG secretion and motor responses occurred slightly earlier in young than older mice. The degree of motor and sudomotor reinnervation, with respect to preoperative control values, was also significantly higher in young than old animals. The differences were more pronounced after 12 months of age. The degree of recovery progressively decreased with the severity of the lesion, differences being more marked in older mice. Neurorraphy improved recovery, comparatively more in older than in young mice. These results indicate that, after injuries of peripheral nerves, axonal regeneration and reinnervation are maintained throughout life, but tend to be more delayed and slightly less effective with aging.

Problems with Excessive Residual Lower Leg Length in Pediatric Amputees

PubMed Central

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

2001-01-01

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

Gait and balance of transfemoral amputees using passive mechanical and microprocessor-controlled prosthetic knees.

PubMed

Kaufman, K R; Levine, J A; Brey, R H; Iverson, B K; McCrady, S K; Padgett, D J; Joyner, M J

2007-10-01

Microprocessor-controlled knee joints appeared on the market a decade ago. These joints are more sophisticated and more expensive than mechanical ones. The literature is contradictory regarding changes in gait and balance when using these sophisticated devices. This study employed a crossover design to assess the comparative performance of a passive mechanical knee prosthesis compared to a microprocessor-controlled knee joint in 15 subjects with an above-knee amputation. Objective measurements of gait and balance were obtained. Subjects demonstrated significantly improved gait characteristics after receiving the microprocessor-controlled prosthetic knee joint (p<0.01). Improvements in gait were a transition from a hyperextended knee to a flexed knee during loading response which resulted in a change from an internal knee flexor moment to a knee extensor moment. The participants' balance also improved (p<0.01). All conditions of the Sensory Organization Test (SOT) demonstrated improvements in equilibrium score. The composite score also increased. Transfemoral amputees using a microprocessor-controlled knee have significant improvements in gait and balance.

Walking speed related joint kinetic alterations in trans-tibial amputees: impact of hydraulic 'ankle' damping.

PubMed

De Asha, Alan R; Munjal, Ramesh; Kulkarni, Jai; Buckley, John G

2013-10-17

Passive prosthetic devices are set up to provide optimal function at customary walking speed and thus may function less effectively at other speeds. This partly explains why joint kinetic adaptations become more apparent in lower-limb amputees when walking at speeds other than customary. The present study determined whether a trans-tibial prosthesis incorporating a dynamic-response foot that was attached to the shank via an articulating hydraulic device (hyA-F) lessened speed-related adaptations in joint kinetics compared to when the foot was attached via a rigid, non-articulating attachment (rigF). Eight active unilateral trans-tibial amputees completed walking trials at their customary walking speed, and at speeds they deemed to be slow-comfortable and fast-comfortable whilst using each type of foot attachment. Moments and powers at the distal end of the prosthetic shank and at the intact joints of both limbs were compared between attachment conditions. There was no change in the amount of intact-limb ankle work across speed or attachment conditions. As speed level increased there was an increase on both limbs in the amount of hip and knee joint work done, and increases on the prosthetic side were greater when using the hyA-F. However, because all walking speed levels were higher when using the hyA-F, the intact-limb ankle and combined joints work per meter travelled were significantly lower; particularly so at the customary speed level. This was the case despite the hyA-F dissipating more energy during stance. In addition, the amount of eccentric work done per meter travelled became increased at the residual knee when using the hyA-F, with increases again greatest at customary speed. Findings indicate that a trans-tibial prosthesis incorporating a dynamic-response foot reduced speed-related changes in compensatory intact-limb joint kinetics when the foot was attached via an articulating hydraulic device compared to rigid attachment. As differences between

Impact of pain in vertebral column on activities of daily living in the Iranian amputees with bilateral lower limb amputation.

PubMed

Ashraf, Alireza; Shojaee, Hadi; Mousavi, Batool; Masoumi, Mehdi; Rezaei, Noushin; Azema, Hasan; Soroush, Mohammadreza

2012-01-01

To determine the impact of pain in the vertebral column on the activities of daily living (ADL) level of war victims with bilateral lower limb amputation. All the war-related bilateral lower limb amputees were invited. More than half of them (n = 335) participated and underwent a thorough assessment after giving informed consent. The majority of the participants were male (97.6%). Their mean age was 42 years and 97.6% of them were married. The most common causes of injury leading to amputation were shells of artillery and mortar (56.7%). The most common level of amputation was bilateral transtibial (37.6%) and 64% were wearing the prosthesis of both sides. The most ADL dependency were transfer activities (27.8%) and bathing (23.3%) and the most independent functioning was eating (97.6%). Upper cervical vertebral pain was associated with dependency in the bowel and bladder management and dressing (p < 0.03 and p < 0.04, respectively). Pain in the lower cervical vertebrae was associated with dependency in toileting and dressing (p < 0.01 and p < 0.01, respectively). There were significant relationships between pain in the thoracic vertebrae and dependency in bathing, transfer activities and toileting (p < 0.02, p < 0.003 and p < 0.03, respectively). Pain in the lumbosacral region had a relationship with the level of amputation, transfer activities and toileting (p < 0.006, p < 0.03 and p < 0.05, respectively). Vertebral pain in bilateral lower limb amputees, especially lumbosacral pain, was accompanied with higher dependency in ADL. Therefore, a multidisciplinary approach to the management of pain is required to minimize disability and maximize functioning.

Biomechanics of ramp descent in unilateral trans-tibial amputees: Comparison of a microprocessor controlled foot with conventional ankle-foot mechanisms.

PubMed

Struchkov, Vasily; Buckley, John G

2016-02-01

Walking down slopes and/or over uneven terrain is problematic for unilateral trans-tibial amputees. Accordingly, 'ankle' devices have been added to some dynamic-response feet. This study determined whether use of a microprocessor controlled passive-articulating hydraulic ankle-foot device improved the gait biomechanics of ramp descent in comparison to conventional ankle-foot mechanisms. Nine active unilateral trans-tibial amputees repeatedly walked down a 5° ramp, using a hydraulic ankle-foot with microprocessor active or inactive or using a comparable foot with rubber ball-joint (elastic) 'ankle' device. When inactive the hydraulic unit's resistances were those deemed to be optimum for level-ground walking, and when active, the plantar- and dorsi-flexion resistances switched to a ramp-descent mode. Residual limb kinematics, joints moments/powers and prosthetic foot power absorption/return were compared across ankle types using ANOVA. Foot-flat was attained fastest with the elastic foot and second fastest with the active hydraulic foot (P<0.001). Prosthetic shank single-support mean rotation velocity (p =0.006), and the flexion (P<0.001) and negative work done at the residual knee (P=0.08) were reduced, and negative work done by the ankle-foot increased (P<0.001) when using the active hydraulic compared to the other two ankle types. The greater negative 'ankle' work done when using the active hydraulic compared to other two ankle types, explains why there was a corresponding reduction in flexion and negative work at the residual knee. These findings suggest that use of a microprocessor controlled hydraulic foot will reduce the biomechanical compensations used to walk down slopes. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Intraneural stimulation elicits discrimination of textural features by artificial fingertip in intact and amputee humans.

PubMed

Oddo, Calogero Maria; Raspopovic, Stanisa; Artoni, Fiorenzo; Mazzoni, Alberto; Spigler, Giacomo; Petrini, Francesco; Giambattistelli, Federica; Vecchio, Fabrizio; Miraglia, Francesca; Zollo, Loredana; Di Pino, Giovanni; Camboni, Domenico; Carrozza, Maria Chiara; Guglielmelli, Eugenio; Rossini, Paolo Maria; Faraguna, Ugo; Micera, Silvestro

2016-03-08

Restoration of touch after hand amputation is a desirable feature of ideal prostheses. Here, we show that texture discrimination can be artificially provided in human subjects by implementing a neuromorphic real-time mechano-neuro-transduction (MNT), which emulates to some extent the firing dynamics of SA1 cutaneous afferents. The MNT process was used to modulate the temporal pattern of electrical spikes delivered to the human median nerve via percutaneous microstimulation in four intact subjects and via implanted intrafascicular stimulation in one transradial amputee. Both approaches allowed the subjects to reliably discriminate spatial coarseness of surfaces as confirmed also by a hybrid neural model of the median nerve. Moreover, MNT-evoked EEG activity showed physiologically plausible responses that were superimposable in time and topography to the ones elicited by a natural mechanical tactile stimulation. These findings can open up novel opportunities for sensory restoration in the next generation of neuro-prosthetic hands.

Upper limb amputees can be induced to experience a rubber hand as their own

PubMed Central

Rosén, Birgitta; Stockselius, Anita; Ragnö, Christina; Köhler, Peter; Lundborg, Göran

2008-01-01

We describe how upper limb amputees can be made to experience a rubber hand as part of their own body. This was accomplished by applying synchronous touches to the stump, which was out of view, and to the index finger of a rubber hand, placed in full view (26 cm medial to the stump). This elicited an illusion of sensing touch on the artificial hand, rather than on the stump and a feeling of ownership of the rubber hand developed. This effect was supported by quantitative subjective reports in the form of questionnaires, behavioural data in the form of misreaching in a pointing task when asked to localize the position of the touch, and physiological evidence obtained by skin conductance responses when threatening the hand prosthesis. Our findings outline a simple method for transferring tactile sensations from the stump to a prosthetic limb by tricking the brain, thereby making an important contribution to the field of neuroprosthetics where a major goal is to develop artificial limbs that feel like a real parts of the body. PMID:19074189

The comparison of transfemoral amputees using mechanical and microprocessor- controlled prosthetic knee under different walking speeds: A randomized cross-over trial.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Meng, Qiaoling; Chen, Wenming

2018-04-20

The microprocessor-controlled prosthetic knees have been introduced to transfemoral amputees due to advances in biomedical engineering. A body of scientific literature has shown that the microprocessor-controlled prosthetic knees improve the gait and functional abilities of persons with transfemoral amputation. The aim of this study was to propose a new microprocessor-controlled prosthetic knee (MPK) and compare it with non-microprocessor-controlled prosthetic knees (NMPKs) under different walking speeds. The microprocessor-controlled prosthetic knee (i-KNEE) with hydraulic damper was developed. The comfortable self-selected walking speeds of 12 subjects with i-KNEE and NMPK were obtained. The maximum swing flexion knee angle and gait symmetry were compared in i-KNEE and NMPK condition. The comfortable self-selected walking speeds of some subjects were higher with i-KNEE while some were not. There was no significant difference in comfortable self-selected walking speed between the i-KNEE and the NMPK condition (P= 0.138). The peak prosthetic knee flexion during swing in the i-KNEE condition was between sixty and seventy degree under any walking speed. In the NMPK condition, the maximum swing flexion knee angle changed significantly. And it increased with walking speed. There is no significant difference in knee kinematic symmetry when the subjects wear the i-KNEE or NMPK. The results of this study indicated that the new microprocessor-controlled prosthetic knee was suitable for transfemoral amputees. The maximum swing flexion knee angle under different walking speeds showed different properties in the NMPK and i-KNEE condition. The i-KNEE was more adaptive to speed changes. There was little difference of comfortable self-selected walking speed between i-KNEE and NMPK condition.

Prosthesis rejection in acquired major upper-limb amputees: a population-based survey.

PubMed

Østlie, Kristin; Lesjø, Ingrid Marie; Franklin, Rosemary Joy; Garfelt, Beate; Skjeldal, Ola Hunsbeth; Magnus, Per

2012-07-01

To estimate the rates of primary and secondary prosthesis rejection in acquired major upper-limb amputees (ULAs), to describe the most frequently reported reasons for rejection and to estimate the influence of background factors on the risk of rejection. Cross-sectional study analysing population-based questionnaire data (n = 224). Effects were analysed by logistic regression analyses and Cox regression analyses. Primary prosthesis rejection was found in 4.5% whereas 13.4% had discontinued prosthesis use. The main reasons reported for primary non-wear were a perceived lack of need and discrepancies between perceived need and the prostheses available. The main reasons reported for secondary prosthesis rejection were dissatisfaction with prosthetic comfort, function and control. Primary prosthesis rejection was more likely in ULAs amputated at high age and in ULAs with proximal amputations. Secondary prosthesis rejection was more likely in proximal ULAs and in women. Clinicians should be aware of the increased risk of rejection in proximal ULAs, elderly ULAs and in women. Emphasising individual needs will probably facilitate successful prosthetic fitting. Improved prosthesis quality and individualised prosthetic training may increase long-term prosthesis use. Further studies of the effect of prosthetic training and of the reasons for rejection of different prosthetic types are suggested.

A Multi-Class Proportional Myocontrol Algorithm for Upper Limb Prosthesis Control: Validation in Real-Life Scenarios on Amputees.

PubMed

Amsuess, Sebastian; Goebel, Peter; Graimann, Bernhard; Farina, Dario

2015-09-01

Functional replacement of upper limbs by means of dexterous prosthetic devices remains a technological challenge. While the mechanical design of prosthetic hands has advanced rapidly, the human-machine interfacing and the control strategies needed for the activation of multiple degrees of freedom are not reliable enough for restoring hand function successfully. Machine learning methods capable of inferring the user intent from EMG signals generated by the activation of the remnant muscles are regarded as a promising solution to this problem. However, the lack of robustness of the current methods impedes their routine clinical application. In this study, we propose a novel algorithm for controlling multiple degrees of freedom sequentially, inherently proportionally and with high robustness, allowing a good level of prosthetic hand function. The control algorithm is based on the spatial linear combinations of amplitude-related EMG signal features. The weighting coefficients in this combination are derived from the optimization criterion of the common spatial patterns filters which allow for maximal discriminability between movements. An important component of the study is the validation of the method which was performed on both able-bodied and amputee subjects who used physical prostheses with customized sockets and performed three standardized functional tests mimicking daily-life activities of varying difficulty. Moreover, the new method was compared in the same conditions with one clinical/industrial and one academic state-of-the-art method. The novel algorithm outperformed significantly the state-of-the-art techniques in both subject groups for tests that required the activation of more than one degree of freedom. Because of the evaluation in real time control on both able-bodied subjects and final users (amputees) wearing physical prostheses, the results obtained allow for the direct extrapolation of the benefits of the proposed method for the end users. In

Misdirection of Regenerating Axons and Functional Recovery Following Sciatic Nerve Injury in Rats

PubMed Central

Hamilton, Shirley K.; Hinkle, Marcus L.; Nicolini, Jennifer; Rambo, Lindsay N.; Rexwinkle, April M.; Rose, Sam J.; Sabatier, Manning J.; Backus, Deborah; English, Arthur W.

2013-01-01

Poor functional recovery found after peripheral nerve injury has been attributed to the misdirection of regenerating axons to reinnervate functionally inappropriate muscles. We applied brief electrical stimulation (ES) to the common fibular (CF) but not the tibial (Tib) nerve just prior to transection and repair of the entire rat sciatic nerve, to attempt to influence the misdirection of its regenerating axons. The specificity with which regenerating axons reinnervated appropriate targets was evaluated physiologically using compound muscle action potentials (M responses) evoked from stimulation of the two nerve branches above the injury site. Functional recovery was assayed using the timing of electromyography (EMG) activity recorded from the tibialis anterior (TA) and soleus (Sol) muscles during treadmill locomotion and kinematic analysis of hindlimb locomotor movements. Selective ES of the CF nerve resulted in restored M-responses at earlier times than in unstimulated controls in both TA and Sol muscles. Stimulated CF axons reinnervated inappropriate targets to a greater extent than unstimulated Tib axons. During locomotion, functional antagonist muscles, TA and Sol, were coactivated both in stimulated rats and in unstimulated but injured rats. Hindlimb kinematics in stimulated rats were comparable to untreated rats, but significantly different from intact controls. Selective ES promotes enhanced axon regeneration but does so with decreased fidelity of muscle reinnervation. Functional recovery is neither improved nor degraded, suggesting that compensatory changes in the outputs of the spinal circuits driving locomotion may occur irrespective of the extent of misdirection of regenerating axons in the periphery. PMID:21120925

Does laryngeal reinnervation or type I thyroplasty give better voice results for patients with unilateral vocal fold paralysis (VOCALIST): study protocol for a feasibility randomised controlled trial.

PubMed

Blackshaw, Helen; Carding, Paul; Jepson, Marcus; Mat Baki, Marina; Ambler, Gareth; Schilder, Anne; Morris, Stephen; Degun, Aneeka; Yu, Rosamund; Husbands, Samantha; Knowles, Helen; Walton, Chloe; Karagama, Yakubu; Heathcote, Kate; Birchall, Martin

2017-09-29

A functioning voice is essential for normal human communication. A good voice requires two moving vocal folds; if one fold is paralysed (unilateral vocal fold paralysis (UVFP)) people suffer from a breathy, weak voice that tires easily and is unable to function normally. UVFP can also result in choking and breathlessness. Current treatment for adults with UVFP is speech therapy to stimulate recovery of vocal fold (VF) motion or function and/or injection of the paralysed VF with a material to move it into a more favourable position for the functioning VF to close against. When these therapies are unsuccessful, or only provide temporary relief, surgery is offered. Two available surgical techniques are: (1) surgical medialisation; placing an implant near the paralysed VF to move it to the middle (thyroplasty) and/or repositioning the cartilage (arytenoid adduction) or (2) restoring the nerve supply to the VF (laryngeal reinnervation). Currently there is limited evidence to determine which surgery should be offered to adults with UVFP. A feasibility study to test the practicality of running a multicentre, randomised clinical trial of surgery for UVFP, including: (1) a qualitative study to understand the recruitment process and how it operates in clinical centres and (2) a small randomised trial of 30 participants recruited at 3 UK sites comparing non-selective laryngeal reinnervation to type I thyroplasty. Participants will be followed up for 12 months. The primary outcome focuses on recruitment and retention, with secondary outcomes covering voice, swallowing and quality of life. Ethical approval was received from National Research Ethics Service-Committee Bromley (reference 11/LO/0583). In addition to dissemination of results through presentation and publication of peer-reviewed articles, results will be shared with key clinician and patient groups required to develop the future large-scale randomised controlled trial. ISRCTN90201732; 16 December 2015. © Article

Does laryngeal reinnervation or type I thyroplasty give better voice results for patients with unilateral vocal fold paralysis (VOCALIST): study protocol for a feasibility randomised controlled trial

PubMed Central

Blackshaw, Helen; Carding, Paul; Jepson, Marcus; Mat Baki, Marina; Ambler, Gareth; Schilder, Anne; Morris, Stephen; Degun, Aneeka; Yu, Rosamund; Husbands, Samantha; Knowles, Helen; Walton, Chloe; Karagama, Yakubu; Heathcote, Kate; Birchall, Martin

2017-01-01

Introduction A functioning voice is essential for normal human communication. A good voice requires two moving vocal folds; if one fold is paralysed (unilateral vocal fold paralysis (UVFP)) people suffer from a breathy, weak voice that tires easily and is unable to function normally. UVFP can also result in choking and breathlessness. Current treatment for adults with UVFP is speech therapy to stimulate recovery of vocal fold (VF) motion or function and/or injection of the paralysed VF with a material to move it into a more favourable position for the functioning VF to close against. When these therapies are unsuccessful, or only provide temporary relief, surgery is offered. Two available surgical techniques are: (1) surgical medialisation; placing an implant near the paralysed VF to move it to the middle (thyroplasty) and/or repositioning the cartilage (arytenoid adduction) or (2) restoring the nerve supply to the VF (laryngeal reinnervation). Currently there is limited evidence to determine which surgery should be offered to adults with UVFP. Methods and analysis A feasibility study to test the practicality of running a multicentre, randomised clinical trial of surgery for UVFP, including: (1) a qualitative study to understand the recruitment process and how it operates in clinical centres and (2) a small randomised trial of 30 participants recruited at 3 UK sites comparing non-selective laryngeal reinnervation to type I thyroplasty. Participants will be followed up for 12 months. The primary outcome focuses on recruitment and retention, with secondary outcomes covering voice, swallowing and quality of life. Ethics and dissemination Ethical approval was received from National Research Ethics Service—Committee Bromley (reference 11/LO/0583). In addition to dissemination of results through presentation and publication of peer-reviewed articles, results will be shared with key clinician and patient groups required to develop the future large-scale randomised

Prosthetic ankle push-off work reduces metabolic rate but not collision work in non-amputee walking.

PubMed

Caputo, Joshua M; Collins, Steven H

2014-12-03

Individuals with unilateral below-knee amputation expend more energy than non-amputees during walking and exhibit reduced push-off work and increased hip work in the affected limb. Simple dynamic models of walking suggest a possible solution, predicting that increasing prosthetic ankle push-off should decrease leading limb collision, thereby reducing overall energy requirements. We conducted a rigorous experimental test of this idea wherein ankle-foot prosthesis push-off work was incrementally varied in isolation from one-half to two-times normal levels while subjects with simulated amputation walked on a treadmill at 1.25 m · s(-1). Increased prosthesis push-off significantly reduced metabolic energy expenditure, with a 14% reduction at maximum prosthesis work. In contrast to model predictions, however, collision losses were unchanged, while hip work during swing initiation was decreased. This suggests that powered ankle push-off reduces walking effort primarily through other mechanisms, such as assisting leg swing, which would be better understood using more complete neuromuscular models.

Prosthetic ankle push-off work reduces metabolic rate but not collision work in non-amputee walking

NASA Astrophysics Data System (ADS)

Caputo, Joshua M.; Collins, Steven H.

2014-12-01

Individuals with unilateral below-knee amputation expend more energy than non-amputees during walking and exhibit reduced push-off work and increased hip work in the affected limb. Simple dynamic models of walking suggest a possible solution, predicting that increasing prosthetic ankle push-off should decrease leading limb collision, thereby reducing overall energy requirements. We conducted a rigorous experimental test of this idea wherein ankle-foot prosthesis push-off work was incrementally varied in isolation from one-half to two-times normal levels while subjects with simulated amputation walked on a treadmill at 1.25 m.s-1. Increased prosthesis push-off significantly reduced metabolic energy expenditure, with a 14% reduction at maximum prosthesis work. In contrast to model predictions, however, collision losses were unchanged, while hip work during swing initiation was decreased. This suggests that powered ankle push-off reduces walking effort primarily through other mechanisms, such as assisting leg swing, which would be better understood using more complete neuromuscular models.

Prosthetic ankle push-off work reduces metabolic rate but not collision work in non-amputee walking

PubMed Central

Caputo, Joshua M.; Collins, Steven H.

2014-01-01

Individuals with unilateral below-knee amputation expend more energy than non-amputees during walking and exhibit reduced push-off work and increased hip work in the affected limb. Simple dynamic models of walking suggest a possible solution, predicting that increasing prosthetic ankle push-off should decrease leading limb collision, thereby reducing overall energy requirements. We conducted a rigorous experimental test of this idea wherein ankle-foot prosthesis push-off work was incrementally varied in isolation from one-half to two-times normal levels while subjects with simulated amputation walked on a treadmill at 1.25 m·s−1. Increased prosthesis push-off significantly reduced metabolic energy expenditure, with a 14% reduction at maximum prosthesis work. In contrast to model predictions, however, collision losses were unchanged, while hip work during swing initiation was decreased. This suggests that powered ankle push-off reduces walking effort primarily through other mechanisms, such as assisting leg swing, which would be better understood using more complete neuromuscular models. PMID:25467389

Skin problems of the stump in lower-limb amputees: 2. Influence on functioning in daily life.

PubMed

Meulenbelt, Henk E J; Geertzen, Jan H B; Jonkman, Marcel F; Dijkstra, Pieter U

2011-03-01

The aim of this study was to analyse the influence of stump skin problems on functioning in daily life in lower-limb amputees. A cross-sectional study was performed by means of a questionnaire containing 9 questions assessing functioning in daily life. Question scores were added to give a total score (range 0 (no influence) to 27 (maximum negative influence)). Two thousand and thirty-nine people were invited to participate, with 805 participants completing a questionnaire. Of these, 507 reported one or more skin problems. Skin problems had a negative influence on ability to perform household tasks, prosthesis use, social functioning, and participation in sports. The mean total score was 5.5 ± 4.1. This correlated significantly with the number of skin complaints (r = 0.483; p = 0.01). In linear regression analyses, gender (β = -0.15) and number of skin problems (β = 0.25) accounted for 23% of the total score. This study confirms the influence of skin problems on functioning in daily life.

[Peripheral nerve repair: 30 centuries of scientific research].

PubMed

Desouches, C; Alluin, O; Mutaftschiev, N; Dousset, E; Magalon, G; Boucraut, J; Feron, F; Decherchi, P

2005-11-01

Nerve injury compromises sensory and motor functions. Techniques of peripheral nerve repair are based on our knowledge regarding regeneration. Microsurgical techniques introduced in the late 1950s and widely developed for the past 20 years have improved repairs. However, functional recovery following a peripheral mixed nerve injury is still incomplete. Good motor and sensory function after nerve injury depends on the reinnervation of the motor end plates and sensory receptors. Nerve regeneration does not begin if the cell body has not survived the initial injury or if it is unable to initiate regeneration. The regenerated axons must reach and reinnervate the appropriate target end-organs in a timely fashion. Recovery of motor function requires a critical number of motor axons reinnervating the muscle fibers. Sensory recovery is possible if the delay in reinnervation is short. Many additional factors influence the success of nerve repair or reconstruction. The timing of the repair, the level of injury, the extent of the zone of injury, the technical skill of the surgeon, and the method of repair and reconstruction contribute to the functional outcome after nerve injury. This review presents the recent advances in understanding of neural regeneration and their application to the management of primary repairs and nerve gaps.

Changes in nerve conduction and Pi/PCr ratio during denervation-reinnervation of the gastrocsoleus muscles of rats

NASA Technical Reports Server (NTRS)

Lai, K. S.; Jaweed, M. M.; Seestead, R.; Herbison, G. J.; Ditunno, J. F. Jr; McCully, K.; Chance, B.

1992-01-01

The purpose of this investigation was to study the changes in nerve conduction and phosphate metabolites of the gastrocsoleus muscles of rats during denervation-reinnervation. Sixteen male Sprague-Dawley rats underwent unilateral crush-denervation of the left sciatic nerves at the sciatic notch. Six rats were used for measurement of motor conduction latency and action potential amplitude of the gastrocsoleus muscle by stimulating the sciatic nerve at one, two and eight weeks after nerve crush. The other ten rats were designated for evaluation of the ratio of inorganic phosphorous (Pi) to phosphocreatine (PCr) by a 31P-phosphoenergetic spectrometer at two weeks and eight weeks after nerve crush. None of the sciatic nerves showed conduction to the gastrocsoleus at one or two weeks after nerve crush. At eight weeks postcrush, the motor conduction latency returned to within normal limits, whereas the action potential amplitude was only 55% of the normal. For the eight-week period of study, the Pi/PCr ratio of the normal control muscles ranged between 0.09 +/- 0.02 and 0.11 +/- 0.02 (mean +/- SD). The denervated muscles showed an increase of Pi/PCr ratio by 54% at two weeks postcrush, compared to the respective contralateral control sides. The ratios returned to the normal value by eight weeks postcrush. In summary, these data suggested that the metabolic recovery of the crush-denervated muscle followed the same pattern as the parameters of nerve conduction.

Preferential Enhancement of Sensory and Motor Axon Regeneration by Combining Extracellular Matrix Components with Neurotrophic Factors

PubMed Central

Santos, Daniel; González-Pérez, Francisco; Giudetti, Guido; Micera, Silvestro; Udina, Esther; Del Valle, Jaume; Navarro, Xavier

2016-01-01

After peripheral nerve injury, motor and sensory axons are able to regenerate but inaccuracy of target reinnervation leads to poor functional recovery. Extracellular matrix (ECM) components and neurotrophic factors (NTFs) exert their effect on different neuronal populations creating a suitable environment to promote axonal growth. Here, we assessed in vitro and in vivo the selective effects of combining different ECM components with NTFs on motor and sensory axons regeneration and target reinnervation. Organotypic cultures with collagen, laminin and nerve growth factor (NGF)/neurotrophin-3 (NT3) or collagen, fibronectin and brain-derived neurotrophic factor (BDNF) selectively enhanced sensory neurite outgrowth of DRG neurons and motor neurite outgrowth from spinal cord slices respectively. For in vivo studies, the rat sciatic nerve was transected and repaired with a silicone tube filled with a collagen and laminin matrix with NGF/NT3 encapsulated in poly(lactic-co-glycolic acid) (PLGA) microspheres (MP) (LM + MP.NGF/NT3), or a collagen and fibronectin matrix with BDNF in PLGA MPs (FN + MP.BDNF). Retrograde labeling and functional tests showed that LM + MP.NGF/NT3 increased the number of regenerated sensory neurons and improved sensory functional recovery, whereas FN + MP.BDNF preferentially increased regenerated motoneurons and enhanced motor functional recovery. Therefore, combination of ECM molecules with NTFs may be a good approach to selectively enhance motor and sensory axons regeneration and promote appropriate target reinnervation. PMID:28036084

Gait Training Interventions for Lower Extremity Amputees: A Systematic Literature Review

PubMed Central

Highsmith, M. Jason; Andrews, Casey R.; Millman, Claire; Fuller, Ashley; Kahle, Jason T.; Klenow, Tyler D.; Lewis, Katherine L.; Bradley, Rachel C.; Orriola, John J.

2016-01-01

Lower extremity (LE) amputation patients who use prostheses have gait asymmetries and altered limb loading and movement strategies when ambulating. Subsequent secondary conditions are believed to be associated with gait deviations and lead to long-term complications that impact function and quality of life as a result. The purpose of this study was to systematically review the literature to determine the strength of evidence supporting gait training interventions and to formulate evidence statements to guide practice and research related to therapeutic gait training for lower extremity amputees. A systematic review of three databases was conducted followed by evaluation of evidence and synthesis of empirical evidence statements (EES). Eighteen manuscripts were included in the review, which covered two areas of gait training interventions: 1) overground and 2) treadmill-based. Eight EESs were synthesized. Four addressed overground gait training, one covered treadmill training, and three statements addressed both forms of therapy. Due to the gait asymmetries, altered biomechanics, and related secondary consequences associated with LE amputation, gait training interventions are needed along with study of their efficacy. Overground training with verbal or other auditory, manual, and psychological awareness interventions was found to be effective at improving gait. Similarly, treadmill-based training was found to be effective: 1) as a supplement to overground training; 2) independently when augmented with visual feedback and/or body weight support; or 3) as part of a home exercise plan. Gait training approaches studied improved multiple areas of gait, including sagittal and coronal biomechanics, spatiotemporal measures, and distance walked. PMID:28066520

Amputation effects on the underlying complexity within transtibial amputee ankle motion

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

Wurdeman, Shane R., E-mail: shanewurdeman@gmail.com; Advanced Prosthetics Center, Omaha, Nebraska 68134; Myers, Sara A.

2014-03-15

The presence of chaos in walking is considered to provide a stable, yet adaptable means for locomotion. This study examined whether lower limb amputation and subsequent prosthetic rehabilitation resulted in a loss of complexity in amputee gait. Twenty-eight individuals with transtibial amputation participated in a 6 week, randomized cross-over design study in which they underwent a 3 week adaptation period to two separate prostheses. One prosthesis was deemed “more appropriate” and the other “less appropriate” based on matching/mismatching activity levels of the person and the prosthesis. Subjects performed a treadmill walking trial at self-selected walking speed at multiple points ofmore » the adaptation period, while kinematics of the ankle were recorded. Bilateral sagittal plane ankle motion was analyzed for underlying complexity through the pseudoperiodic surrogation analysis technique. Results revealed the presence of underlying deterministic structure in both prostheses and both the prosthetic and sound leg ankle (discriminant measure largest Lyapunov exponent). Results also revealed that the prosthetic ankle may be more likely to suffer loss of complexity than the sound ankle, and a “more appropriate” prosthesis may be better suited to help restore a healthy complexity of movement within the prosthetic ankle motion compared to a “less appropriate” prosthesis (discriminant measure sample entropy). Results from sample entropy results are less likely to be affected by the intracycle periodic dynamics as compared to the largest Lyapunov exponent. Adaptation does not seem to influence complexity in the system for experienced prosthesis users.« less

Neuromechanical sensor fusion yields highest accuracies in predicting ambulation mode transitions for trans-tibial amputees.

PubMed

Tkach, D C; Hargrove, L J

2013-01-01

Advances in battery and actuator technology have enabled clinical use of powered lower limb prostheses such as the BiOM Powered Ankle. To allow ambulation over various types of terrains, such devices rely on built-in mechanical sensors or manual actuation by the amputee to transition into an operational mode that is suitable for a given terrain. It is unclear if mechanical sensors alone can accurately modulate operational modes while voluntary actuation prevents seamless, naturalistic gait. Ensuring that the prosthesis is ready to accommodate new terrain types at first step is critical for user safety. EMG signals from patient's residual leg muscles may provide additional information to accurately choose the proper mode of prosthesis operation. Using a pattern recognition classifier we compared the accuracy of predicting 8 different mode transitions based on (1) prosthesis mechanical sensor output (2) EMG recorded from residual limb and (3) fusion of EMG and mechanical sensor data. Our findings indicate that the neuromechanical sensor fusion significantly decreases errors in predicting 10 mode transitions as compared to using either mechanical sensors or EMG alone (2.3±0.7% vs. 7.8±0.9% and 20.2±2.0% respectively).

Target of physiological gait: Realization of speed adaptive control for a prosthetic knee during swing flexion.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Li, Jin; Wei, Xiaodong

2018-01-01

Prosthetic knee is the most important component of lower limb prosthesis. Speed adaptive for prosthetic knee during swing flexion is the key method to realize physiological gait. This study aims to discuss the target of physiological gait, propose a speed adaptive control method during swing flexion and research the damping adjustment law of intelligent hydraulic prosthetic knee. According to the physiological gait trials of healthy people, the control target during swing flexion is defined. A new prosthetic knee with fuzzy logical control during swing flexion is designed to realize the damping adjustment automatically. The function simulation and evaluation system of intelligent knee prosthesis is provided. Speed adaptive control test of the intelligent prosthetic knee in different velocities are researched. The maximum swing flexion of the knee angle is set between sixty degree and seventy degree as the target of physiological gait. Preliminary experimental results demonstrate that the prosthetic knee with fuzzy logical control is able to realize physiological gait under different speeds. The faster the walking, the bigger the valve closure percentage of the hydraulic prosthetic knee. The proposed fuzzy logical control strategy and intelligent hydraulic prosthetic knee are effective for the amputee to achieve physiological gait.

Mobility and satisfaction with a microprocessor-controlled knee in moderately active amputees: A multi-centric randomized crossover trial.

PubMed

Lansade, Céline; Vicaut, Eric; Paysant, Jean; Ménager, Doménico; Cristina, Marie-Christine; Braatz, Frank; Domayer, Stephan; Pérennou, Dominic; Chiesa, Gérard

2018-05-14

Microprocessor-controlled knees are generally prescribed and reimbursed for active amputees. Recent studies suggested that this technology could be useful for amputees with moderate activity level. We compared the efficiency of a microprocessor-controlled knee (MPK, Kenevo, Otto Bock) and non-MPKs (NMPKs) in these indications. A multi-centric randomized crossover trial was conducted in 16 hospitals from 3 European countries. Participants were randomized to an MPK-NMPK sequence, testing the MPK for 3 months and the NMPK for 1 month, or to an NMPK-MPK sequence, testing the NMPK for 1 month and the MPK for 3 months. Dynamic balance, the main criteria, was assessed with the Timed-Up and Go test (TUG), functional mobility with the Locomotor Capability Index (LCI-5), quality of life with the Medical Outcomes Study Short Form 36 v2 (SF-36v2) and satisfaction with the Quebec User Evaluation of Satisfaction with Assistive Technology 2.0. The occurrence of falls was monitored during the last month of trial. Analysis was by intent-to-treat and per-protocol (PP). We recruited 35 individuals with transfemoral amputation or knee disarticulation (27 males; mean age 65.6years [SD 10.1]). On PP analysis, dynamic balance and functional mobility were improved with the MPK, as shown by a reduced median TUG time (from 21.4s [Q1-Q3 19.3-26.6] to 17.9s [15.4-22.7], P=0.001) and higher mean global LCI-5 (from 40.4 [SD 7.6] to 42.8 [6.2], P=0.02). Median global satisfaction score increased (from 3.9 [Q1-Q3 3.8-4.4] to 4.7 [4.1-4.9], P=0.001) and quality of life was improved for the mental component summary of the SF-36v2 (median score from 53.3 [Q1-Q3 47.8-60.7] to 60.2 [51.6-62.6], P=0.03) and physical component summary but not significantly (mean score from 44.1 [SD 6.3] to 46.3 [7.0], P=0.08). Monitoring of adverse events including falls revealed no differences between both assessed devices. This study enhances the level of evidence to argue equal opportunity for all individuals with

ECONOMIC EVALUATIONS OF INTERVENTIONS FOR TRANSTIBIAL AMPUTEES: A SCOPING REVIEW OF COMPARATIVE STUDIES.

PubMed

Highsmith, M Jason; Kahle, Jason T; Lewandowski, Amanda; Klenow, Tyler D; Orriola, John J; Miro, Rebecca M; Hill, Owen T; Raschke, Sylvia Ursula; Orendurff, Michael S; Highsmith, James T; Sutton, Bryce S

2016-09-01

Transtibial amputation (TTA) is life-altering emotionally, functionally, and economically. The economic impact to all stakeholders is largely unknown, as is the cost-effectiveness of prosthetic intervention. This scoping report's purpose was to determine if there is sufficient evidence to conduct a formal systematic review or meta-analysis in any particular prosthetic intervention area and to determine if any evidence statements could be synthesized relative to economic evaluation of interventions provided to patients with TTA. The scoping review revealed six articles representing three topical areas of transtibial care: Care Models, Prosthetic Treatment, and Prosthetic Sockets. All six articles were cost-identification or cost-consequence design and included a total of 704 subjects. Presently, it can be concluded with moderate confidence that specific weight-bearing and total-contact sockets for transtibial amputees are functionally and economically equivalent in the short term when costs, delivery time, and all stakeholder perspectives are considered. Long-term socket outcomes are relatively unexplored. Further primary research is needed beyond this to determine cost-effectiveness for other areas of transtibial prosthetic care although clinical outcomes are somewhat established through systematic review and meta-analysis in other areas of care. Conversely, evaluation of narrative economic reports relative to transtibial care may be sufficient to warrant further analysis. Guidance from the profession may also be useful in devising a strategy for how to assure economic analyses are a routine element of future prosthetic science.

Modeling the interactions between a prosthetic socket, polyurethane liners and the residual limb in transtibial amputees using non-linear finite element analysis.

PubMed

Simpson, G; Fisher, C; Wright, D K

2001-01-01

Continuing earlier studies into the relationship between the residual limb, liner and socket in transtibial amputees, we describe a geometrically accurate non-linear model simulating the donning of a liner and then a socket. The socket is rigid and rectified and the liner is a polyurethane geltype which is accurately described using non-linear (Mooney-Rivlin) material properties. The soft tissue of the residual limb is modelled as homogeneous, non-linear and hyperelastic and the bone structure within the residual limb is taken as rigid. The work gives an indication of how the stress induced by the process of donning the rigid socket is redistributed by the liner. Ultimately we hope to understand how the liner design might be modified to reduce discomfort. The ANSYS finite element code, version 5.6 is used.

Evaluation of a new geriatric foot versus the Solid Ankle Cushion Heel foot for low-activity amputees.

PubMed

Bonnet, Xavier; Adde, Jean N; Blanchard, François; Gedouin-Toquet, Annick; Eveno, Dominique

2015-04-01

It is always a challenge to rehabilitate geriatric amputees to perform self-care skills at home with limited ambulation. A new geriatric foot (with a lower effective foot length) has been specifically designed to reduce residual limb stress and to ease the step completion. The aim of this study is to evaluate the benefit of a new geriatric foot versus a Solid Ankle Cushion Heel foot for low-activity persons with transtibial amputation. Crossover study. A total of 12 patients were included in this study. 2-min walking test, Quebec User Evaluation of Satisfaction with Assistive Technology 2.0 questionnaire and pressure socket measurements. The geriatric foot allows for greater patient satisfaction. The maximal pressure was significantly lower in the proximal anterior stump area. No statistical differences were obtained from the 2-min walking test. A geriatric foot designed with a low effective foot length improves the satisfaction and reduces proximal anterior socket pressures for poor-performing persons with transtibial amputation. The development and evaluation of feet specifically designed for geriatric persons with transtibial amputation could improve their specific requirements and satisfaction. © The International Society for Prosthetics and Orthotics 2014.

The biomechanics of one-footed vertical jump performance in unilateral trans-tibial amputees.

PubMed

Strike, S C; Diss, C

2005-04-01

This study investigated vertical jumps from single support for two trans-tibial amputees from a standing position. The mechanisms used to achieve flight and the compensatory mechanisms used in the production of force in the absence of plantarflexors are detailed. Two participants completed countermovement maximum vertical jumps from the prosthetic and the sound limbs. The jumps were recorded by a 7-camera 512 VICON motion analysis system integrated with a Kistler forceplate. Flight height was 5 cm jumping from the prosthetic side and 18-19 cm from the sound side. The countermovement was shallower and its duration was less on the prosthetic side compared to the sound side. The reduced and passive range of motion at the prosthesis resulted in an asymmetrical countermovement for both participants with the knee and ankle joints most affected. The duration of the push-off phase was not consistently affected. At take-off the joints on the sound side reached close to full extension while on the prosthetic side they remained more flexed. Joint extension velocity in the push-off phase was similar for both participants on the sound side, though the timing for participant 2 illustrated earlier peaks. The pattern of joint extension velocity was not a smooth proximal to distal sequence on the prosthetic side. The magnitude and timing of the inter-segment extensor moments were asymmetrical for both subjects. The power pattern was asymmetrical in both the countermovement and push-off phases; the lack of power generation at the ankle affected that produced at the remaining joints.

Confocal Comparison of Corneal Reinnervation after Small Incision Lenticule Extraction (SMILE) and Femtosecond Laser In Situ Keratomileusis (FS-LASIK)

PubMed Central

Qin, Bing; Zhou, Zimei; Ni, Katherine; Le, Qihua; Xiang, Jun; Wei, Anji; Ma, Weiping; Zhou, Xingtao

2013-01-01

Purpose To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK). Methods In this prospective, non-randomized observational study, 18 patients (32 eyes) received SMILE surgery, and 22 patients (42 eyes) received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. Results The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147), 1 month (P = 0.0243), and 3 months (P = 0.0498), but no difference was detected at the 6-month visit (P = 0.5277). The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively). The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005). Conclusions The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity. PMID:24349069

Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).

PubMed

Li, Meiyan; Niu, Lingling; Qin, Bing; Zhou, Zimei; Ni, Katherine; Le, Qihua; Xiang, Jun; Wei, Anji; Ma, Weiping; Zhou, Xingtao

2013-01-01

To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK). In this prospective, non-randomized observational study, 18 patients (32 eyes) received SMILE surgery, and 22 patients (42 eyes) received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147), 1 month (P = 0.0243), and 3 months (P = 0.0498), but no difference was detected at the 6-month visit (P = 0.5277). The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively). The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005). The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.

Hands-Off and Hands-On Casting Consistency of Amputee below Knee Sockets Using Magnetic Resonance Imaging

PubMed Central

Rowe, Philip

2013-01-01

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit. PMID:24348164

Clinical field follow-up of high density polyethylene (HDPE)-Jaipur prosthetic technology for trans-tibial amputees.

PubMed

Jensen, J S; Craig, J G; Mtalo, L B; Zelaya, C M

2004-12-01

The purpose of this study was to examine the outcome of the application of the High Density Polyethylene (HDPE)-Jaipur prosthetic construction in fitting trans-tibial amputees in a number of projects in the developing world. Projects in Honduras, Uganda and India were visited. Three hundred and twenty (320) patients had been provided with a HDPE-Jaipur prosthesis and of these 172 were seen for a technical and clinical follow-up after a median of 35 months. More than half the amputations were due to trauma, the remainder to disease. Fabrication and fitting in the three projects was carried out by individuals who had undertaken a twice week training course provided by Bhagwan Mahaveer Viklang Sahayata Samiti limb centre in Jaipur. The individuals involved had limited background training in prosthetics. Craftsmanship and fit were assessed as being poor in 56% of cases. The technical quality of the Jaipur foot was considered acceptable as its performance was better than previously observed results. Although there was patient satisfaction of 85% and compliance of 94% the HDPE-Jaipur trans-tibial system was not considered acceptable as 49% reported walking distances less than 1km and 36% discomfort. The major inadequacy in outcome relates to the use for fabrication and fitting of individuals with inadequate education and training.

Hands-off and hands-on casting consistency of amputee below knee sockets using magnetic resonance imaging.

PubMed

Safari, Mohammad Reza; Rowe, Philip; McFadyen, Angus; Buis, Arjan

2013-01-01

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit.

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

PubMed

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

2016-11-01

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

Sensory Feedback for Lower Extremity Prostheses Incorporating Targeted Muscle Reinnervation (TMR)

DTIC Science & Technology

2016-10-01

amputation to establish baselines and guide development. The second technique makes use of Virtual Reality ( VR ) to provide visual and tactile...of view in VR (left) and real world (right) Figure 6: Confidence for offsets presented to Site 1 (closest to the knee) on the right in blue, and...presentations Three presentations were given at the Northwest Biomechanics Symposium 2016 Technologies or techniques We have pioneered a VR

Clinical and theoretical parallels between desire for limb amputation and gender identity disorder.

PubMed

Lawrence, Anne A

2006-06-01

Desire for amputation of a healthy limb has usually been regarded as a paraphilia (apotemnophilia), but some researchers propose that it may be a disorder of identity, similar to Gender Identity Disorder (GID) or transsexualism. Similarities between the desire for limb amputation and nonhomosexual male-to-female (MtF) transsexualism include profound dissatisfaction with embodiment, related paraphilias from which the conditions plausibly derive (apotemnophilia and autogynephilia), sexual arousal from simulation of the sought-after status (pretending to be an amputee and transvestism), attraction to persons with the same body type one wants to acquire, and an elevated prevalence of other paraphilic interests. K. Freund and R. Blanchard (1993) proposed that nonhomosexual MtF transsexualism represents an erotic target location error, in which men whose preferred erotic targets are women also eroticize their own feminized bodies. Desire for limb amputation may also reflect an erotic target location error, occurring in combination with an unusual erotic target preference for amputees. This model predicts that persons who desire limb amputation would almost always be attracted to amputees and would display an increased prevalence of gender identity problems, both of which have been observed. Persons who desire limb amputation and nonhomosexual MtF transsexuals often assert that their motives for wanting to change their bodies reflect issues of identity rather than sexuality, but because erotic/romantic orientations contribute significantly to identity, such distinctions may not be meaningful. Experience with nonhomosexual MtF transsexualism suggests possible directions for research and treatment for persons who desire limb amputation.

Designing for scale: development of the ReMotion Knee for global emerging markets.

PubMed

Hamner, Samuel R; Narayan, Vinesh G; Donaldson, Krista M

2013-09-01

Amputees living in developing countries have a profound need for affordable and reliable lower limb prosthetic devices. The World Health Organization estimates there are approximately 30 million amputees living in low-income countries, with up to 95% lacking access to prosthetic devices. Effective prosthetics can significantly affect the lives of these amputees by increasing opportunity for employment and providing improvements to long-term health and well-being. However, current solutions are inadequate: state-of-the-art solutions from the US and Europe are cost-prohibitive, while low-cost devices have been challenged by poor quality and/or unreliable performance, and have yet to achieve large scale impact. The introduction of new devices is hampered by the lack of a cohesive prosthetics industry in low-income areas; the current network of low-cost prosthetic clinics is informal and loosely organized with significant disparities in geography, patient volume and demographics, device procurement, clinical and logistical infrastructure, and funding. At D-Rev (Design Revolution) we are creating the ReMotion Knee, which is an affordable polycentric prosthetic knee joint that performs on par with devices in more industrialized regions, like the US and Europe. As of September 2012, over 4200 amputees have been fitted with the initial version of the ReMotion Knee through a partnership with the JaipurFoot Organization, with an 79% compliance rate after 2 years. We are currently scaling production of the ReMotion Knee using centralized manufacturing and distribution to serve the existing clinics in low-income countries and increase the availability of devices for amputees without access to appropriate care. At D-Rev, we develop products that target these customers through economically-sustainable models and provide a measurable impact in the lives of the world's amputees.

BIOENERGETIC DIFFERENCES DURING WALKING AND RUNNING IN TRANSFEMORAL AMPUTEE RUNNERS USING ARTICULATING AND NON-ARTICULATING KNEE PROSTHESES

PubMed Central

Highsmith, M. Jason; Kahle, Jason T.; Miro, Rebecca M.; Mengelkoch, Larry J.

2016-01-01

Transfemoral amputation (TFA) patients require considerably more energy to walk and run than non-amputees. The purpose of this study was to examine potential bioenergetic differences (oxygen uptake (VO2), heart rate (HR), and ratings of perceived exertion (RPE)) for TFA patients utilizing a conventional running prosthesis with an articulating knee mechanism versus a running prosthesis with a non-articulating knee joint. Four trained TFA runners (n = 4) were accommodated to and tested with both conditions. VO2 and HR were significantly lower (p ≤ 0.05) in five of eight fixed walking and running speeds for the prosthesis with an articulating knee mechanism. TFA demonstrated a trend for lower RPE at six of eight walking speeds using the prosthesis with the articulated knee condition. A trend was observed for self-selected walking speed, self-selected running speed, and maximal speed to be faster for TFA subjects using the prosthesis with the articulated knee condition. Finally, all four TFA participants subjectively preferred running with the prosthesis with the articulated knee condition. These findings suggest that, for trained TFA runners, a running prosthesis with an articulating knee prosthesis reduces ambulatory energy costs and enhances subjective perceptive measures compared to using a non-articulating knee prosthesis. PMID:28066524

Motor unit and muscle fiber type grouping after peripheral nerve injury in the rat.

PubMed

Gordon, Tessa; de Zepetnek, Joanne E Totosy

2016-11-01

Muscle unit (MU) fibers innervated by one motoneuron and corresponding muscle fiber types are normally distributed in a mosaic. We asked whether, 4-8months after common peroneal nerve transection and random surgical alignment of nerve stumps in rat tibialis anterior muscles 1) reinnervated MU muscle and muscle fiber type clumping is invariant and 2) slow and fast motoneurons regenerate their nerve fibers within original endoneurial pathways. MU contractile forces were recorded in vivo, the MUs classified into types according to their contractile speed and fatigability, and one MU subjected to alternate exhaustive stimulation-recovery cycles to deplete glycogen for histochemical MU fiber recognition and enumeration, and muscle fiber typing. MU muscle fibers occupied defined territories whose size increased with MU force and muscle fiber numbers in normal and reinnervated muscles. The reinnervated MU muscle fiber territories were significantly smaller, the fibers clumped within 1-3 groups in 90% of the MUs, and each fiber lying adjacent to another significantly more frequently. Most reinnervated slow muscle fibers were normally located in the deep muscle compartment but substantial numbers were located abnormally in the superficial compartment. Our findings that well reinnervated muscle fibers clump in small muscles contrast with our earlier findings of clumping in large muscles only when reinnervated MU numbers were significantly reduced. We conclude that fiber type clumping is predictive of muscle reinnervation in small but not large muscles. In the latter muscles, clumping is more indicative of sprouting after partial nerve injuries than of muscle reinnervation after complete nerve injuries. Copyright © 2016 Elsevier Inc. All rights reserved.

The biomechanical effect of arm mass on long jump performance: A case study of a paralympic upper limb amputee.

PubMed

Pradon, Didier; Mazure-Bonnefoy, Alice; Rabita, Giuseppe; Hutin, Emilie; Zory, Raphael; Slawinski, Jean

2014-06-01

The role of arm motion during the long jump has been well studied. The aim of this study was to quantify the effect of forearm mass on impulse and the kinematics of the flight phase in an upper limb amputee. A world-record paralympic long jumper carried out jumps in three conditions: wearing his usual forearm prosthesis and with 0.3 and 0.4 kg added mass. A motion capture system including force plates was used to record the jump. At take-off, the addition of 0.4 kg to the prosthesis decreased the vertical velocity of the centre of mass but increased horizontal velocity. These modifications were associated with an increase in landing distance and an improvement of the synchronization between arms. Increasing forearm mass appears to improve long jump performance. Further studies need to evaluate the optimal prosthetic mass for both training and competition. This biomechanical analysis of the long jump highlighted the effects of changing prosthesis mass on performance. This methodological approach may be useful in the context of sport and performance research. © The International Society for Prosthetics and Orthotics 2013.

Comparison of different microprocessor controlled knee joints on the energy consumption during walking in trans-femoral amputees: intelligent knee prosthesis (IP) versus C-leg.

PubMed

Chin, Takaaki; Machida, Katsuhiro; Sawamura, Seishi; Shiba, Ryouichi; Oyabu, Hiroko; Nagakura, Yuji; Takase, Izumi; Nakagawa, Akio

2006-04-01

The purpose of this study was to investigate the characteristic differences between the IP and C-Leg by making a comparative study of energy consumption and walking speeds in trans-femoral amputees. The subjects consisted of four persons with traumatic trans-femoral amputations aged 17 - 33 years who had been using the IP and were active in society. Fourteen able-bodied persons served as controls. First the energy consumption at walking speeds of 30, 50, 70, and 90 m/min was measured when using the IP. Then the knee joint was switched to the C-Leg. The same energy consumption measurement was taken once the subjects were accustomed to using the C-Leg. The most metabolically efficient walking speed was also determined. At a walking speed of 30 m/min using the IP and C-Leg, the oxygen rate (ml/kg/ min) was, on average, 42.5% and 33.3% higher (P< 0.05) than for the able-bodied group. At 50 m/min, the equivalent figures were 56.6% and 49.5% (P< 0.05), while at 70 m/min the figures were 57.8% and 51.2% (P<0.05), and at 90m/min the figures were 61.9% and 55.2% (P<0.05%). Comparing the oxygen rates for the subjects using the IP and C-Leg at walking speeds of 30 m/min and 90 m/min it was found that subjects who used C-Leg walked somewhat more efficiently than those who used IP. However, there was no significant difference between the two types at each walking speed. It was also determined that the most energy-efficient walking speed for subjects using the IP and C-Leg was the same as for the controls. Although the subjects in this study walked with comparable speed and efficiency whether they used the IP or C-Leg, the subjects' energy consumption while walking with the IP and C-Leg at normal speeds were much lower than previously reported. This study suggested that the microprocessor controlled knee joints appeared to be valid alternative for improving walking performance of trans-femoral amputees.

Sport prostheses and prosthetic adaptations for the upper and lower limb amputees: an overview of peer reviewed literature.

PubMed

Bragaru, Mihai; Dekker, Rienk; Geertzen, Jan H B

2012-09-01

Sport prostheses are used by both upper- and lower-limb amputees while participating in sports and other physical activities. Although the number of these devices has increased over the past decade, no overview of the peer reviewed literature describing them has been published previously. Such an overview will allow specialists to choose appropriate prostheses based on available scientific evidence rather than on personal experience or preference. To provide an overview of the sport prostheses as they are described by the papers published in peer reviewed literature. Literature review. Four electronic databases were searched using free text and Medical Subject Headings (MESH) terms. Papers were included if they concerned a prosthesis or a prosthetic adaptation used in sports. Papers were excluded if they did not originate from peer reviewed sources, if they concerned prostheses for body parts other than the upper or lower limbs, if they concerned amputations distal to the wrist or ankle, or if they were written in a language other than English. Twenty-four papers were included in this study. The vast majority contained descriptive data and consisted of expert opinions and technical notes. Data concerning the energy efficiency, technical characteristics and special mechanical properties of prostheses or prosthetic adaptations for sports, other than running, are scarce.

A quasi-dynamic nonlinear finite element model to investigate prosthetic interface stresses during walking for trans-tibial amputees.

PubMed

Jia, Xiaohong; Zhang, Ming; Li, Xiaobing; Lee, Winson C C

2005-07-01

To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. Interface pressure distribution was found to have the same profile during walking. The high pressures fall over popliteal depression, middle patella tendon, lateral tibia and medial tibia regions. Interface pressure predicted by static or quasi-dynamic analysis had the similar double-peaked waveform shape in stance phase. The consideration of inertial effects and motion of knee joint cause 210% average variation of the area between the pressure curve and the horizontal line of pressure threshold between two cases, even though there is only a small change in the peak pressure. The findings in this paper show that the coupling dynamic effects of inertial loads and knee flexion must be considered to study interface pressure between residual limb and prosthetic socket during walking.

Effect of prosthetic alignment changes on socket reaction moment impulse during walking in transtibial amputees

PubMed Central

Kobayashi, Toshiki; Orendurff, Michael S.; Arabian, Adam K.; Rosenbaum-Chou, Teri G.; Boone, David A.

2014-01-01

The alignment of a lower limb prosthesis affects the way load is transferred to the residual limb through the socket, and this load is critically important for the comfort and function of the prosthesis. Both magnitude and duration of the moment are important factors that may affect the residual limb health. Moment impulse is a well-accepted measurement that incorporates both factors via moment–time integrals. The aim of this study was to investigate the effect of alignment changes on the socket reaction moment impulse in transtibial prostheses. Ten amputees with transtibial prostheses participated in this study. The socket reaction moment impulse was measured at a self-selected walking speed using a Smart Pyramid™ in 25 alignment conditions, including a nominal alignment (clinically aligned by a prosthetist), as well as angle malalignments of 2°, 4° and 6° (abduction, adduction, extension and flexion) and translation malalignments of 5 mm, 10 mm and 15 mm (lateral, medial, anterior and posterior). The socket reaction moment impulse of the nominal alignment was compared for each condition. The relationship between the alignment and the socket reaction moment impulse was clearly observed in the coronal angle, coronal translation and sagittal translation alignment changes. However, this relationship was not evident in the sagittal angle alignment changes. The results of this study suggested that the socket reaction moment impulse could potentially serve as a valuable parameter to assist the alignment tuning process for transtibial prostheses. Further study is needed to investigate the influence of the socket reaction moment impulse on the residual limb health. PMID:24612718

Techniques for Interface Stress Measurements within Prosthetic Sockets of Transtibial Amputees: A Review of the Past 50 Years of Research.

PubMed

Al-Fakih, Ebrahim A; Abu Osman, Noor Azuan; Mahmad Adikan, Faisal Rafiq

2016-07-20

The distribution of interface stresses between the residual limb and prosthetic socket of a transtibial amputee has been considered as a direct indicator of the socket quality fit and comfort. Therefore, researchers have been very interested in quantifying these interface stresses in order to evaluate the extent of any potential damage caused by the socket to the residual limb tissues. During the past 50 years a variety of measurement techniques have been employed in an effort to identify sites of excessive stresses which may lead to skin breakdown, compare stress distributions in various socket designs, and evaluate interface cushioning and suspension systems, among others. The outcomes of such measurement techniques have contributed to improving the design and fitting of transtibial sockets. This article aims to review the operating principles, advantages, and disadvantages of conventional and emerging techniques used for interface stress measurements inside transtibial sockets. It also reviews and discusses the evolution of different socket concepts and interface stress investigations conducted in the past five decades, providing valuable insights into the latest trends in socket designs and the crucial considerations for effective stress measurement tools that lead to a functional prosthetic socket.

Techniques for Interface Stress Measurements within Prosthetic Sockets of Transtibial Amputees: A Review of the Past 50 Years of Research

PubMed Central

Al-Fakih, Ebrahim A.; Abu Osman, Noor Azuan; Mahmad Adikan, Faisal Rafiq

2016-01-01

The distribution of interface stresses between the residual limb and prosthetic socket of a transtibial amputee has been considered as a direct indicator of the socket quality fit and comfort. Therefore, researchers have been very interested in quantifying these interface stresses in order to evaluate the extent of any potential damage caused by the socket to the residual limb tissues. During the past 50 years a variety of measurement techniques have been employed in an effort to identify sites of excessive stresses which may lead to skin breakdown, compare stress distributions in various socket designs, and evaluate interface cushioning and suspension systems, among others. The outcomes of such measurement techniques have contributed to improving the design and fitting of transtibial sockets. This article aims to review the operating principles, advantages, and disadvantages of conventional and emerging techniques used for interface stress measurements inside transtibial sockets. It also reviews and discusses the evolution of different socket concepts and interface stress investigations conducted in the past five decades, providing valuable insights into the latest trends in socket designs and the crucial considerations for effective stress measurement tools that lead to a functional prosthetic socket. PMID:27447646

Corneal Re-innervation and Sensation Recovery in Patients with Herpes Zoster Ophthalmicus: An In Vivo and Ex Vivo Study of Corneal Nerves

PubMed Central

Cruzat, Andrea; Hamrah, Pedram; Cavalcanti, Bernardo M.; Zheng, Lixin; Colby, Kathryn; Pavan-Langston, Deborah

2016-01-01

Purpose To study corneal reinnervation and sensation recovery in Herpes zoster Ophthalmicus (HZO). Methods Two patients with HZO were studied over time with serial corneal esthesiometry and laser in vivo confocal microscopy (IVCM). A Boston keratoprosthesis (B-KPro) type 1 was implanted and the explanted corneal tissues were examined by immunofluorescence histochemistry for βIII-tubulin to stain for corneal nerves. Results The initial central corneal IVCM performed in each patient, showed a complete lack of the subbasal nerve plexus, which was in accordance with severe loss of sensation (0 of 6 cm) measured by esthesiometry. When IVCM was repeated 2 years later prior to undergoing surgery, Case 1 showed a persistent lack of central subbasal nerves and sensation (0 of 6). In contrast, Case 2 showed regeneration of the central subbasal nerves (4,786 µm/mm2) with partial recovery of corneal sensation (2.5 of 6 cm). Immunostaining of the explanted corneal button in Case 1 showed no corneal nerves while Case 2, showed central and peripheral corneal nerves. Eight months after surgery, IVCM was again repeated in the donor tissue around the B-KPro in both patients, to study innervation of the corneal transplant. Case 1 showed no nerves, while Case 2 showed new nerves growing from the periphery into the corneal graft. Conclusions We demonstrate that regaining corneal innervation and function is possible in patients with HZO as shown by corneal sensation, IVCM, and ex-vivo immunostaining, indicating zoster neural damage is not always permanent and it may recover over an extended period of time. PMID:26989956

Changes in crossed spinal reflexes after peripheral nerve injury and repair.

PubMed

Valero-Cabré, Antoni; Navarro, Xavier

2002-04-01

We investigated the changes induced in crossed extensor reflex responses after peripheral nerve injury and repair in the rat. Adults rats were submitted to non repaired sciatic nerve crush (CRH, n = 9), section repaired by either aligned epineurial suture (CS, n = 11) or silicone tube (SIL4, n = 13), and 8 mm resection repaired by tubulization (SIL8, n = 12). To assess reinnervation, the sciatic nerve was stimulated proximal to the injury site, and the evoked compound muscle action potential (M and H waves) from tibialis anterior and plantar muscles and nerve action potential (CNAP) from the tibial nerve and the 4th digital nerve were recorded at monthly intervals for 3 mo postoperation. Nociceptive reinnervation to the hindpaw was also assessed by plantar algesimetry. Crossed extensor reflexes were evoked by stimulation of the tibial nerve at the ankle and recorded from the contralateral tibialis anterior muscle. Reinnervation of the hindpaw increased progressively with time during the 3 mo after lesion. The degree of muscle and sensory target reinnervation was dependent on the severity of the injury and the nerve gap created. The crossed extensor reflex consisted of three bursts of activity (C1, C2, and C3) of gradually longer latency, lower amplitude, and higher threshold in control rats. During follow-up after sciatic nerve injury, all animals in the operated groups showed recovery of components C1 and C2 and of the reflex H wave, whereas component C3 was detected in a significantly lower proportion of animals in groups with tube repair. The maximal amplitude of components C1 and C2 recovered to values higher than preoperative values, reaching final levels between 150 and 245% at the end of the follow-up in groups CRH, CS, and SIL4. When reflex amplitude was normalized by the CNAP amplitude of the regenerated tibial nerve, components C1 (300-400%) and C2 (150-350%) showed highly increased responses, while C3 was similar to baseline levels. In conclusion

[Study of bone mass with dual energy x-ray absorptiometry in a population of 99 lower limb amputees].

PubMed

Leclercq, M M; Bonidan, O; Haaby, E; Pierrejean, C; Sengler, J

2003-02-01

Osteopenia in lower extremity amputation is described with an increased risk of fracture and it seems to be interesting to study bone mass in a population of 99 amputees of limb. We studied the bone mass with Dual Energy Xray Absorptiometry in patients with limb amputation, above and under knee and who have been treated in the rehabilitation department of Mulhouse's hospital and more specifically the percentage of the difference of the mesure between amputed and non amputed side and the influence on this mesure of several factors like sexe; age; diabetes mellitus; delay of amputation; aetiology and use of prosthesis. For all the population, we find lower values of BMD (Bone mineral density) for femoral neck -10.4% +/- 12.2 (P < 0,001) and trochanter -14.9% +/- 14.5 (P < 0,001) between amputated and non amputated side, and also comparing with normal population -19.9% +/- 18.8 (P < 0,001) for femoral neck and -8.8% +/- 22 (P < 0,001) for trochanter.There is no influence of sexe, age, and time since amputation on BMD. The study of sub-groupes shows that the loss of bone mass is depending on traumatic amputation, the level of amputation (above knee) and when prothetis doesn't fit. Arteritis or diabetis are not pejoratif factors. This work confirms the mechanical factors as an important parameter of bone loss in the limb amputation.

Strategies for providing upper extremity amputees with tactile and hand position feedback--moving closer to the bionic arm.

PubMed

Riso, R R

1999-01-01

A continuing challenge for prostheses developers is to replace the sensory function of the hand. This includes tactile sensitivity such as finger contact, grip force, object slippage, surface texture and temperature, as well as proprioceptive sense. One approach is sensory substitution whereby an intact sensory system such as vision, hearing or cutaneous sensation elsewhere on the body is used as an input channel for information related to the prosthesis. A second technique involves using electrical stimulation to deliver sensor derived information directly to the peripheral afferent nerves within the residual limb. Stimulation of the relevant afferent nerves can ultimately come closest to restoring the original sensory perceptions of the hand, and to this end, researchers have already demonstrated some degree of functionality of the transected sensory nerves in studies with amputee subjects. This paper provides an overview of different types of nerve interface components and the advantages and disadvantages of employing each of them in sensory feedback systems. Issues of sensory perception, neurophysiology and anatomy relevant to hand sensation and function are discussed with respect to the selection of the different types of nerve interfaces. The goal of this paper is to outline what can be accomplished for implementing sensation into artificial arms in the near term by applying what is present or presently attainable technology.

Effect of prosthetic alignment changes on socket reaction moment impulse during walking in transtibial amputees.

PubMed

Kobayashi, Toshiki; Orendurff, Michael S; Arabian, Adam K; Rosenbaum-Chou, Teri G; Boone, David A

2014-04-11

The alignment of a lower limb prosthesis affects the way load is transferred to the residual limb through the socket, and this load is critically important for the comfort and function of the prosthesis. Both magnitude and duration of the moment are important factors that may affect the residual limb health. Moment impulse is a well-accepted measurement that incorporates both factors via moment-time integrals. The aim of this study was to investigate the effect of alignment changes on the socket reaction moment impulse in transtibial prostheses. Ten amputees with transtibial prostheses participated in this study. The socket reaction moment impulse was measured at a self-selected walking speed using a Smart Pyramid in 25 alignment conditions, including a nominal alignment (clinically aligned by a prosthetist), as well as angle malalignments of 2°, 4° and 6° (abduction, adduction, extension and flexion) and translation malalignments of 5 mm, 10 mm and 15 mm (lateral, medial, anterior and posterior). The socket reaction moment impulse of the nominal alignment was compared for each condition. The relationship between the alignment and the socket reaction moment impulse was clearly observed in the coronal angle, coronal translation and sagittal translation alignment changes. However, this relationship was not evident in the sagittal angle alignment changes. The results of this study suggested that the socket reaction moment impulse could potentially serve as a valuable parameter to assist the alignment tuning process for transtibial prostheses. Further study is needed to investigate the influence of the socket reaction moment impulse on the residual limb health. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of a prosthesis shoulder mechanism for upper limb amputees: application of an original design methodology to optimize functionality and wearability.

PubMed

Troncossi, Marco; Borghi, Corrado; Chiossi, Marco; Davalli, Angelo; Parenti-Castelli, Vincenzo

2009-05-01

The application of a design methodology for the determination of the optimal prosthesis architecture for a given upper limb amputee is presented in this paper along with the discussion of its results. In particular, a novel procedure was used to provide the main guidelines for the design of an actuated shoulder articulation for externally powered prostheses. The topology and the geometry of the new articulation were determined as the optimal compromise between wearability (for the ease of use and the patient's comfort) and functionality of the device (in terms of mobility, velocity, payload, etc.). This choice was based on kinematic and kinetostatic analyses of different upper limb prosthesis models and on purpose-built indices that were set up to evaluate the models from different viewpoints. Only 12 of the 31 simulated prostheses proved a sufficient level of functionality: among these, the optimal solution was an articulation having two actuated revolute joints with orthogonal axes for the elevation of the upper arm in any vertical plane and a frictional joint for the passive adjustment of the humeral intra-extra rotation. A prototype of the mechanism is at the clinical test stage.

Socket Interface Pressure and Amputee Reported Outcomes for Comfortable and Uncomfortable Conditions of Patellar Tendon Bearing Socket: A Pilot Study.

PubMed

Safari, Mohammad Reza; Tafti, Nahid; Aminian, Gholamreza

2015-01-01

The objectives of the current study were to compare intra-socket pressure differences between comfortable and uncomfortable socket conditions, and the usefulness of subject perception of satisfaction, activity limitations, and socket comfort in distinguishing between these two socket conditions. Five unilateral trans-tibial amputees took part in the study. They answered the Socket Comfort Score (SCS) and Trinity Amputation and Prosthetic Experience Scale (TAPES) questionnaires before the interface pressure (in standing and walking) was measured for the uncomfortable socket condition at five regions of the residual limb. Participants were then provided with a comfortable socket and wore it for two weeks. Participants who were satisfied with the socket fit after two weeks repeated the SCS and TAPES questionnaires and interface pressure measurements. The differences between the test results of the two conditions were not statistically significant, except for the interface pressure at the popliteal region during the early stance phase, TAPES socket fit subscale, and the SCS. Due to large variability of the data and the lack of statistical significance, no firm conclusion can be made on the possible relationship between the interface pressure values and the patient-reported outcomes of the two socket conditions. A larger sample size and longer acclimation period are required to locate significant differences.

Structural and functional changes in corneal innervation after laser in situ keratomileusis and their relationship with dry eye.

PubMed

Chao, Cecilia; Stapleton, Fiona; Zhou, Xiangtian; Chen, Shihao; Zhou, Shi; Golebiowski, Blanka

2015-11-01

The most likely etiology of post-LASIK dry eye is corneal nerve damage; however, no direct relationship between post-LASIK dry eye symptoms and nerve damage has been established, and limited information is available about the relationship between dry eye signs and corneal reinnervation after LASIK. Tear neuropeptides (SP and CGRP) are important in the maintenance of corneal nerve health, but the impact of LASIK has not yet been studied. This study evaluated changes in nerve morphology, tear neuropeptide, and dry eye, so as to establish the relationship between reinnervation and dry eye and to assess the role of tear neuropeptides in reinnervation post-LASIK. Twenty non-dry eye volunteers who had undergone bilateral myopic-LASIK completed this study. Corneal nerve morphology (density, width, interconnections, and tortuosity), SP and CGRP concentration, and dry eye were monitored over time prior to, 1 day, 1 week, 1, 3, and 6 months post-LASIK. Dry eye symptoms and tear function, except for osmolarity (P = 0.003), remained unchanged post-LASIK. Corneal nerve morphology decreased immediately, and did not return to preoperative levels by 6 months post-LASIK (P < 0.001). Increased tear SP concentration was observed 3 months post-LASIK (P < 0.001). Associations between reinnervation as measured by increased density and lower tear SP (P = 0.03), and between increased density and decreased dry eye symptoms (P = 0.01) were found post-LASIK. An inverse relationship between reinnervation post-LASIK and dry eye symptoms was found, confirming that post-LASIK dry eye is a neuropathic disease. This study is the first to demonstrate an association between tear SP and post-LASIK reinnervation, suggesting that strategies for manipulating neuropeptide concentration to improve reinnervation may improve ocular comfort post-LASIK.

Effects of electrode size and spacing on sensory modalities in the phantom thumb perception area for the forearm amputees.

PubMed

Li, P; Chai, G H; Zhu, K H; Lan, N; Sui, X H

2015-01-01

Tactile sensory feedback plays a key role in accomplishing the dexterous manipulation of prosthetic hands for the amputees, and the non-invasive transcutaneous electrical nerve stimulation (TENS) of the phantom finger perception (PFP) area would be an effective way to realize sensory feedback clinically. In order to realize the high-spatial-resolution tactile sensory feedback in the PFP region, we investigated the effects of electrode size and spacing on the tactile sensations for potentially optimizing the surface electrode array configuration. Six forearm-amputated subjects were recruited in the psychophysical studies. With the diameter of the circular electrode increasing from 3 mm to 12 mm, the threshold current intensity was enhanced correspondingly under different sensory modalities. The smaller electrode could potentially lead to high sensation spatial resolution. Whereas, the smaller the electrode, the less the number of sensory modalities. For an Φ-3 mm electrode, it is even hard for the subject to perceive any perception modalities under normal stimulating current. In addition, the two-electrode discrimination distance (TEDD) in the phantom thumb perception area decreased with electrode size decreasing in two directions of parallel or perpendicular to the forearm. No significant difference of TEDD existed along the two directions. Studies in this paper would guide the configuration optimization of the TENS electrode array for potential high spatial-resolution sensory feedback.

Regulation of step frequency in transtibial amputee endurance athletes using a running-specific prosthesis.

PubMed

Oudenhoven, Laura M; Boes, Judith M; Hak, Laura; Faber, Gert S; Houdijk, Han

2017-01-25

Running specific prostheses (RSP) are designed to replicate the spring-like behaviour of the human leg during running, by incorporating a real physical spring in the prosthesis. Leg stiffness is an important parameter in running as it is strongly related to step frequency and running economy. To be able to select a prosthesis that contributes to the required leg stiffness of the athlete, it needs to be known to what extent the behaviour of the prosthetic leg during running is dominated by the stiffness of the prosthesis or whether it can be regulated by adaptations of the residual joints. The aim of this study was to investigate whether and how athletes with an RSP could regulate leg stiffness during distance running at different step frequencies. Seven endurance runners with an unilateral transtibial amputation performed five running trials on a treadmill at a fixed speed, while different step frequencies were imposed (preferred step frequency (PSF) and -15%, -7.5%, +7.5% and +15% of PSF). Among others, step time, ground contact time, flight time, leg stiffness and joint kinetics were measured for both legs. In the intact leg, increasing step frequency was accompanied by a decrease in both contact and flight time, while in the prosthetic leg contact time remained constant and only flight time decreased. In accordance, leg stiffness increased in the intact leg, but not in the prosthetic leg. Although a substantial contribution of the residual leg to total leg stiffness was observed, this contribution did not change considerably with changing step frequency. Amputee athletes do not seem to be able to alter prosthetic leg stiffness to regulate step frequency during running. This invariant behaviour indicates that RSP stiffness has a large effect on total leg stiffness and therefore can have an important influence on running performance. Nevertheless, since prosthetic leg stiffness was considerably lower than stiffness of the RSP, compliance of the residual leg should

Recovery of C-fiber-induced extravasation following peripheral nerve injury in the rat.

PubMed

Bester, H; Allchorne, A J; Woolf, C J

1998-12-01

Peripheral nerve injury leads to substantial alterations in injured sensory neurons. These include cell death, phenotypic modifications, and regeneration. Primary sensory neurons have recently been shown not to die until a time beyond 4 months following a nerve crush or ligation and this loss is, moreover, limited to cells with unmyelinated axons, the C-fibers. The late loss of C-fibers may be due to a lack of target reinnervation during the regenerative phase. In order to investigate this, we have used a particular peripheral function, unique to C-fibers, as a measure of peripheral reinnervation: an increase in capillary permeability on antidromic activation of C-fibers, i.e., neurogenic extravasation. This was investigated in rats that had received a nerve crush injury 1 to 50 weeks earlier. Some recovery of the capacity of C-fibers to generate extravasation was detected at 8-10 weeks, which increased further at 12-14 weeks, and then plateaued at this level with no further recovery at 30 or 50 weeks. In intact and damaged sciatic nerves, A beta-fibers never induced extravasation. These findings are compatible with the hypothesis that those C-fibers which make it back to their peripheral targets do not subsequently die and those that do not, may die. Copyright 1998 Academic Press.

Motor nerve transplantation.

PubMed

Gray, W P; Keohane, C; Kirwan, W O

1997-10-01

The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 microsec preoperatively, and 26 microsec at 2 months, 29.5 microsec at 4 months, and 14 microsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.

The quality of life analysis of knee prosthesis with complete microprocessor control in trans-femoral amputees.

PubMed

Saglam, Yavuz; Gulenc, Baris; Birisik, Fevzi; Ersen, Ali; Yilmaz Yalcinkaya, Ebru; Yazicioglu, Onder

2017-12-01

The aim of this study was to analyze the patient demographics, etiology of limb loss as well as reporting SF-36 scores for microprocessor prosthesis users in Turkish population. We reviewed 72 patients (61 male and 11 female; mean age: 37.7 ± 10.7) with uni-lateral, above knee amputation and a history of regular and microprocessor prosthesis use. All patients were called back for a last follow-up and they were asked to fill a self-administered general health status questionnaire (SF-36). According to the SF-36 results; physical component score (PCS) score was 46 ± 7.3 and mental components summary (MCS) score was 46.5 ± 9.1. These scores have statistical similarity with Turkish healthy controls, except SF (social functioning) sub-dimension. PCS score for women microprocessor users were significantly lower than men (43.3 vs. 48.7, p = 0.03), but MCS scores were similar in between genders (46 vs. 48.2, p = 0.13). Conventional prostheses usage time was positively correlated with physical function (PF) scores (r = 0.322, p = 0.010). Microprocessor prosthesis usage time was negatively correlated with role limitations due to emotional problem (RE) scores (r = -0,313, p = 0.009). The quality of life surveys were showed that the loss of an extremity have higher physical and psychological impact on women's physical scores. Overall, SF-36 results were similar in microprocessor using amputee's and Turkish normal controls. Level IV, therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

The effects of mirror therapy on pain and motor control of phantom limb in amputees: A systematic review.

PubMed

Barbin, J; Seetha, V; Casillas, J M; Paysant, J; Pérennou, D

2016-09-01

Phantom limb pain (PLP) is a major problem after limb amputation. Mirror therapy (MT) is a non-pharmacological treatment using representations of movement, the efficacy of which in reducing PLP remains to be clarified. Here, we present the first systematic review on MT efficacy in PLP and phantom limb movement (PLM) in amputees (lower or upper limb). A search on Medline, Cochrane Database and Embase, crossing the keywords "Phantom Limb" and "Mirror Therapy" found studies which were read and analyzed according the PRISMA statement. Twenty studies were selected, 12 on the subject of MT and PLP, 3 on MT and PLM, 5 on MT and both (PLP and PLM). Among these 20 studies, 5 were randomized controlled trials (163 patients), 6 prospective studies (55 patients), 9 case studies (40 patients) and methodologies were heterogeneous. Seventeen of the 18 studies reported the efficacy of MT on PLP, but with low levels of evidence. One randomized controlled trial did not show any significant effect of MT. As to the effect of MT on PLM, the 8 studies concerned reported effectiveness of MT: 4 with a low level of evidence and 4 with a high level of evidence. An alternative to visual illusion seems to be tactile or auditory stimulation. We cannot recommend MT as a first intention treatment in PLP. The level of evidence is insufficient. Further research is needed to assess the effect of MT on pain, prosthesis use, and body representation, and to standardize protocols. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

What does low-intensity rTMS do to the cerebellum?

PubMed

Morellini, N; Grehl, S; Tang, A; Rodger, J; Mariani, J; Lohof, A M; Sherrard, R M

2015-02-01

Non-invasive stimulation of the human cerebellum, such as by transcranial magnetic stimulation (TMS), is increasingly used to investigate cerebellar function and identify potential treatment for cerebellar dysfunction. However, the effects of TMS on cerebellar neurons remain poorly defined. We applied low-intensity repetitive TMS (LI-rTMS) to the mouse cerebellum in vivo and in vitro and examined the cellular and molecular sequelae. In normal C57/Bl6 mice, 4 weeks of LI-rTMS using a complex biomimetic high-frequency stimulation (BHFS) alters Purkinje cell (PC) dendritic and spine morphology; the effects persist 4 weeks after the end of stimulation. We then evaluated whether LI-rTMS could induce climbing fibre (CF) reinnervation to denervated PCs. After unilateral pedunculotomy in adult mice and 2 weeks sham or BHFS stimulation, VGLUT2 immunohistochemistry was used to quantify CF reinnervation. In contrast to sham, LI-rTMS induced CF reinnervation to the denervated hemicerebellum. To examine potential mechanisms underlying the LI-rTMS effect, we verified that BHFS could induce CF reinnervation using our in vitro olivocerebellar explants in which denervated cerebellar tissue is co-cultured adjacent to intact cerebella and treated with brain-derived neurotrophic factor (BDNF) (as a positive control), sham or LI-rTMS for 2 weeks. Compared with sham, BDNF and BHFS LI-rTMS significantly increased CF reinnervation, without additive effect. To identify potential underlying mechanisms, we examined intracellular calcium flux during the 10-min stimulation. Complex high-frequency stimulation increased intracellular calcium by release from intracellular stores. Thus, even at low intensity, rTMS modifies PC structure and induces CF reinnervation.

Long-term outcomes of unilateral transtibial amputations.

PubMed

Ebrahimzadeh, Mohamad H; Hariri, Sanaz

2009-06-01

the long-term outcomes of wartime transtibial amputations have not been well documented. The purpose of this case series is to present the long-term functional, social, and psychological outcomes of modern-day military unilateral transtibial amputees. the Iranian Veterans Administration of the Khorasan province invited their Iranian military amputees from the Iran-Iraq War (1980-1988) to its medical center for evaluation. The patients filled out a detailed questionnaire and were interviewed and examined by each team member. two hundred (77%) of the 260 invited amputees were willing and able to come back for follow-up. Ninety-six of these patients (48%) were unilateral transtibial amputation. The average follow-up was 17.4 years (range 15-22 years). Land mines were the leading cause of war injury necessitating a transtibial amputation (68%). The most common symptoms about their amputated limbs were phantom sensations (54%), phantom pain (17%), and stump pain (42%). Lower back pain, contralateral (nonamputated limb) knee pain, and ipsilateral (amputated limb) knee pain were reported by 44%, 38%, and 13% of subjects, respectively. Sixty-five percent of patients were employed or had been employed for multiple years after their war injury. All patients were married, and 97% had children. Fifty-four percent of amputees reported psychological problems; 26% were currently utilizing psychological support services. at long-term follow-up, most military transtibial amputees experienced phantom sensation or some type of stump pain. More than half had persistent psychiatric problems, but only about half of these patients were receiving psychological treatment. Although this case series reports the status of these amputees, the next step would be to prospectively follow modern wartime amputees using standardized, validated outcome measures. With the goal of optimizing long-term amputee outcomes, researchers should correlate outcomes with demographics, injury characteristics, and

Robotic lower limb prosthesis design through simultaneous computer optimizations of human and prosthesis costs

NASA Astrophysics Data System (ADS)

Handford, Matthew L.; Srinivasan, Manoj

2016-02-01

Robotic lower limb prostheses can improve the quality of life for amputees. Development of such devices, currently dominated by long prototyping periods, could be sped up by predictive simulations. In contrast to some amputee simulations which track experimentally determined non-amputee walking kinematics, here, we explicitly model the human-prosthesis interaction to produce a prediction of the user’s walking kinematics. We obtain simulations of an amputee using an ankle-foot prosthesis by simultaneously optimizing human movements and prosthesis actuation, minimizing a weighted sum of human metabolic and prosthesis costs. The resulting Pareto optimal solutions predict that increasing prosthesis energy cost, decreasing prosthesis mass, and allowing asymmetric gaits all decrease human metabolic rate for a given speed and alter human kinematics. The metabolic rates increase monotonically with speed. Remarkably, by performing an analogous optimization for a non-amputee human, we predict that an amputee walking with an appropriately optimized robotic prosthesis can have a lower metabolic cost - even lower than assuming that the non-amputee’s ankle torques are cost-free.

Upslope treadmill exercise enhances motor axon regeneration but not functional recovery following peripheral nerve injury

PubMed Central

Cannoy, Jill; Crowley, Sam; Jarratt, Allen; Werts, Kelly LeFevere; Osborne, Krista; Park, Sohee

2016-01-01

Following peripheral nerve injury, moderate daily exercise conducted on a level treadmill results in enhanced axon regeneration and modest improvements in functional recovery. If the exercise is conducted on an upwardly inclined treadmill, even more motor axons regenerate successfully and reinnervate muscle targets. Whether this increased motor axon regeneration also results in greater improvement in functional recovery from sciatic nerve injury was studied. Axon regeneration and muscle reinnervation were studied in Lewis rats over an 11 wk postinjury period using stimulus evoked electromyographic (EMG) responses in the soleus muscle of awake animals. Motor axon regeneration and muscle reinnervation were enhanced in slope-trained rats. Direct muscle (M) responses reappeared faster in slope-trained animals than in other groups and ultimately were larger than untreated animals. The amplitude of monosynaptic H reflexes recorded from slope-trained rats remained significantly smaller than all other groups of animals for the duration of the study. The restoration of the amplitude and pattern of locomotor EMG activity in soleus and tibialis anterior and of hindblimb kinematics was studied during treadmill walking on different slopes. Slope-trained rats did not recover the ability to modulate the intensity of locomotor EMG activity with slope. Patterned EMG activity in flexor and extensor muscles was not noted in slope-trained rats. Neither hindblimb length nor limb orientation during level, upslope, or downslope walking was restored in slope-trained rats. Slope training enhanced motor axon regeneration but did not improve functional recovery following sciatic nerve transection and repair. PMID:27466130

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

PubMed

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

2017-10-23

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

Modified first or second cervical nerve transplantation technique for the treatment of recurrent laryngeal neuropathy in horses.

PubMed

Rossignol, F; Brandenberger, O; Perkins, J D; Marie, J-P; Mespoulhès-Rivière, C; Ducharme, N G

2018-07-01

In horses, the only established method for reinnervation of the larynx is the nerve-muscle pedicle implantation, whereas in human medicine, direct nerve implantation is a standard surgical technique for selective laryngeal reinnervation in human patients suffering from bilateral vocal fold paralysis. (1) To describe a modified first or second cervical nerve transplantation technique for the treatment of recurrent laryngeal neuropathy (RLN) in horses and (2) evaluate the outcomes of reinnervation using direct nerve needle-stimulation of the first cervical nerve and exercising endoscopy before and after surgery. Case series. Nerve transplantation surgery, in which the first or second cervical nerve is tunnelled through the atrophied left cricoarytenoideus dorsalis muscle, was performed in combination with ipsilateral laser ventriculocordectomy. Ultrasound-guided stimulation of the first cervical nerve at the level of the alar foramen was used to confirm successful reinnervation post-operatively. Exercising endoscopy was performed before and after surgery. The exercising RLN grade of the left arytenoid was blindly determined at the highest stride frequency for each examination. Surgery was performed in 17 client-owned animals with RLN. Reinnervation was confirmed by nerve stimulation and subsequent arytenoid abduction observed in 11 out of 12 cases between 4 and 12 months post-operatively. Fourteen horses had exercising endoscopy before and after surgery. Nine horses had an improved exercising RLN grade, four horses had the same exercising grade and one horse had a worse exercising grade after surgery. A sham-operated control group was not included and follow-up beyond 12 months and objective performance data were not obtained. The modified first or second cervical nerve transplantation technique, using tunnelling and direct implantation of the donor nerve into the cricoarytenoideus dorsalis muscle, resulted in reinnervation in 11 out of 12 cases and improved

Progressive upper limb prosthetics.

PubMed

Lake, Chris; Dodson, Robert

2006-02-01

The field of upper extremity prosthetics is a constantly changing arena as researchers and prosthetists strive to bridge the gap between prosthetic reality and upper limb physiology. With the further development of implantable neurologic sensing devices and targeted muscle innervation (discussed elsewhere in this issue), the challenge of limited input to control vast outputs promises to become a historical footnote in the future annals of upper limb prosthetics. Soon multidextrous terminal devices, such as that found in the iLimb system(Touch EMAS, Inc., Edinburgh, UK), will be a clinical reality (Fig. 22). Successful prosthetic care depends on good communication and cooperation among the surgeon, the amputee, the rehabilitation team, and the scientists harnessing the power of technology to solve real-life challenges. If the progress to date is any indication, amputees of the future will find their dreams limited only by their imagination.

Engagement in activities revealing the body and psychosocial adjustment in adults with a trans-tibial prosthesis.

PubMed

Donovan-Hall, M K; Yardley, L; Watts, R J

2002-04-01

The purpose of this study was to examine the effects of the appearance of a prosthesis on social behaviour, social discomfort and psychological well-being in eleven amputees taking delivery of a prosthesis with a silicone cover. Two new scales were developed: the 'Engagement in everyday activities involving revealing the body' (EEARB); and the 'Discomfort-Engagement in everyday activities involving revealing the body' (Discomfort-EEARB) scales. The psychometric properties of these scales were determined using a sample of 101 able-bodied adults. The Hospital Anxiety and Depression Scale and the Rosenberg Self-Esteem Scale were also used to measure psychological well-being in the amputee sample. The EEARB and Discomfort-EEARB proved to have good reliability and validity. Comparison of amputees' scores prior to receiving the silicone cosmesis with those of the able-bodied adults revealed significant behavioural limitations and social discomfort, associated with low self-esteem, anxiety and depression. There was a significant increase in amputees' scores three months afier taking delivery of their prosthesis, indicating that amputees reported engaging in more activities which involved revealing their body, and that they would feel more comfortable in situations which involved revealing the body. As the amputee sample available was small and self-selected, it is not possible to generalise these findings to the amputee population as a whole. However, since there is little previous research investigating the effects of the appearance of the prosthesis, these findings demonstrate the need for further research in this area.

Electro-cutaneous stimulation on the palm elicits referred sensations on intact but not on amputated digits

NASA Astrophysics Data System (ADS)

D'Alonzo, M.; Engels, L. F.; Controzzi, M.; Cipriani, C.

2018-02-01

Objective. Grasping and manipulation control critically depends on tactile feedback. Without this feedback, the ability for fine control of a prosthesis is limited in upper limb amputees. Early studies have shown that non-invasive electro-cutaneous stimulation (ES) can induce referred sensations that are spread to a wider and/or more distant area, with respect to the electrodes. Building on this, we sought to exploit this effect to provide somatotopically matched sensory feedback to people with partial hand (digital) amputations. Approach. For the first time, this work investigated the possibility of inducing referred sensations in the digits by activating the palmar nerves. Specifically, we electrically stimulated 18 sites on the palm of non-amputees to evaluate the effects of sites and stimulation parameters on modality, magnitude, and location of the evoked sensations. We performed similar tests with partial hand amputees by testing those sites that had most consistently elicited referred sensations in non-amputees. Main results. We demonstrated referred sensations in non-amputees from all stimulation sites in one form or another. Specifically, the stimulation of 16 of the 18 sites gave rise to reliable referred sensations. Amputees experienced referred sensations to unimpaired digits, just like non-amputees, but we were unable to evoke referred sensations in their missing digits: none of them reported sensations that extended beyond the tip of the stump. Significance. The possibility of eliciting referred sensations on the digits may be exploited in haptic systems for providing touch sensations without obstructing the fingertips or their movements. The study also suggests that the phenomenon of referred sensations through ES may not be exploited for partial hand prostheses, and it invites researchers to explore alternative approaches. Finally, the results seem to confirm previous studies suggesting that the stumps in partial hand amputees partially acquire the

Partial Denervation of Subbasal Axons Persists Following Debridement Wounds to the Mouse Cornea

PubMed Central

Pajoohesh-Ganji, Ahdeah; Pal-Ghosh, Sonali; Tadvalkar, Gauri; Kyne, Briana M.; Saban, Daniel R.; Stepp, Mary Ann

2015-01-01

Although sensory reinnervation occurs after injury in the PNS, poor reinnervation in the elderly and those with diabetes often leads to pathology. Here we quantify subbasal axon density in the central and peripheral mouse cornea over time after three different types of injury. The mouse cornea is highly innervated with a dense array of subbasal nerves that form a spiral called the vortex at the corneal center or apex; these nerves are readily detected within flat mounted corneas. After anesthesia, corneal epithelial cells were removed using either a dulled blade or a rotating burr within an area demarcated centrally with a 1.5 mm trephine. A third wound type, superficial trephination, involved demarcating the area with the 1.5 mm trephine but not removing cells. By 7d after superficial trephination, subbasal axon density returns to control levels; by 28d the vortex reforms. Although axon density is similar to control 14d after dulled blade and rotating burr wounding, defects in axon morphology at the corneal apex remain. After 14d, axons retract from the center leaving the subbasal axon density reduced by 37.2% and 36.8% at 28d after dulled blade and rotating burr wounding, respectively, compared to control. Assessment of inflammation using flow cytometry shows that persistent inflammation is not a factor in the incomplete reinnervation. Expression of mRNAs encoding 22 regeneration associated genes (RAGs) involved in axon targeting assessed by QPCR reveals that netrin-1 and ephrin signaling are altered after wounding. Subpopulations of corneal epithelial basal cells at the corneal apex stop expressing ki67 as early as 7d after injury and by 14d and 28d after wounding, many of these basal cells undergo apoptosis and die. While subbasal axons are restored to their normal density and morphology after superficial trephination, subbasal axon recovery is partial after debridement wounds. The increase in corneal epithelial basal cell apoptosis at the apex observed at 14d

Partial denervation of sub-basal axons persists following debridement wounds to the mouse cornea.

PubMed

Pajoohesh-Ganji, Ahdeah; Pal-Ghosh, Sonali; Tadvalkar, Gauri; Kyne, Briana M; Saban, Daniel R; Stepp, Mary Ann

2015-11-01

Although sensory reinnervation occurs after injury in the peripheral nervous system, poor reinnervation in the elderly and those with diabetes often leads to pathology. Here we quantify sub-basal axon density in the central and peripheral mouse cornea over time after three different types of injury. The mouse cornea is highly innervated with a dense array of sub-basal nerves that form a spiral called the vortex at the corneal center or apex; these nerves are readily detected within flat mounted corneas. After anesthesia, corneal epithelial cells were removed using either a dulled blade or a rotating burr within an area demarcated centrally with a 1.5 mm trephine. A third wound type, superficial trephination, involved demarcating the area with the 1.5 mm trephine but not removing cells. By 7 days after superficial trephination, sub-basal axon density returns to control levels; by 28 days the vortex reforms. Although axon density is similar to control 14 days after dulled blade and rotating burr wounding, defects in axon morphology at the corneal apex remain. After 14 days, axons retract from the center leaving the sub-basal axon density reduced by 37.2 and 36.8% at 28 days after dulled blade and rotating burr wounding, respectively, compared with control. Assessment of inflammation using flow cytometry shows that persistent inflammation is not a factor in the incomplete reinnervation. Expression of mRNAs encoding 22 regeneration-associated genes involved in axon targeting assessed by QPCR reveals that netrin-1 and ephrin signaling are altered after wounding. Subpopulations of corneal epithelial basal cells at the corneal apex stop expressing ki67 as early as 7 days after injury and by 14 and 28 days after wounding, many of these basal cells undergo apoptosis and die. Although sub-basal axons are restored to their normal density and morphology after superficial trephination, sub-basal axon recovery is partial after debridement wounds. The increase in corneal

An Analysis of Intrinsic and Extrinsic Hand Muscle EMG for Improved Pattern Recognition Control.

PubMed

Adewuyi, Adenike A; Hargrove, Levi J; Kuiken, Todd A

2016-04-01

Pattern recognition control combined with surface electromyography (EMG) from the extrinsic hand muscles has shown great promise for control of multiple prosthetic functions for transradial amputees. There is, however, a need to adapt this control method when implemented for partial-hand amputees, who possess both a functional wrist and information-rich residual intrinsic hand muscles. We demonstrate that combining EMG data from both intrinsic and extrinsic hand muscles to classify hand grasps and finger motions allows up to 19 classes of hand grasps and individual finger motions to be decoded, with an accuracy of 96% for non-amputees and 85% for partial-hand amputees. We evaluated real-time pattern recognition control of three hand motions in seven different wrist positions. We found that a system trained with both intrinsic and extrinsic muscle EMG data, collected while statically and dynamically varying wrist position increased completion rates from 73% to 96% for partial-hand amputees and from 88% to 100% for non-amputees when compared to a system trained with only extrinsic muscle EMG data collected in a neutral wrist position. Our study shows that incorporating intrinsic muscle EMG data and wrist motion can significantly improve the robustness of pattern recognition control for application to partial-hand prosthetic control.

An Analysis of Intrinsic and Extrinsic Hand Muscle EMG for Improved Pattern Recognition Control

PubMed Central

Adewuyi, Adenike A.; Hargrove, Levi J.; Kuiken, Todd A.

2015-01-01

Pattern recognition control combined with surface electromyography (EMG) from the extrinsic hand muscles has shown great promise for control of multiple prosthetic functions for transradial amputees. There is, however, a need to adapt this control method when implemented for partial-hand amputees, who possess both a functional wrist and information-rich residual intrinsic hand muscles. We demonstrate that combining EMG data from both intrinsic and extrinsic hand muscles to classify hand grasps and finger motions allows up to 19 classes of hand grasps and individual finger motions to be decoded, with an accuracy of 96% for non-amputees and 85% for partial-hand amputees. We evaluated real-time pattern recognition control of three hand motions in seven different wrist positions. We found that a system trained with both intrinsic and extrinsic muscle EMG data, collected while statically and dynamically varying wrist position increased completion rates from 73% to 96% for partial-hand amputees and from 88% to 100% for non-amputees when compared to a system trained with only extrinsic muscle EMG data collected in a neutral wrist position. Our study shows that incorporating intrinsic muscle EMG data and wrist motion can significantly improve the robustness of pattern recognition control for partial-hand applications. PMID:25955989

Bipolar electrocautery: A rodent model of Sunderland third-degree nerve injury.

PubMed

Moradzadeh, Arash; Brenner, Michael J; Whitlock, Elizabeth L; Tong, Alice Y; Luciano, Janina P; Hunter, Daniel A; Myckatyn, Terence M; Mackinnon, Susan E

2010-01-01

To determine the Sunderland classification of a bipolar electrocautery injury. Twenty-two rats received crush (a reproducible Sunderland second-degree injury) or bipolar electrocautery injury and were evaluated for functional, histomorphometric, and immunohistochemical recovery at 21 or 42 days. Animal experiments were performed between July 3 and December 12, 2007. Axonal regeneration and end plate reinnervation were evaluated in double transgenic cyan fluorescent protein-conjugated Thy1 and green fluorescent protein-conjugated S100 mice. Compared with crush injury, bipolar electrocautery injury caused greater disruption of myelin and neurofilament architecture at the injury site and decreased nerve fiber counts and percentage of neural tissue distal to the injury (P =.007). Complete functional recovery was seen after crush but not bipolar electrocautery injury. Serial live imaging demonstrated axonal regeneration at week 1 after crush and at week 3 after bipolar electrocautery injury. Qualitative assessment of motor end plate reinnervation at 42 days demonstrated complete neuromuscular end plate reinnervation in the crush group and only limited reinnervation in the bipolar electrocautery group. Bipolar electrocautery injury in a rodent model resulted in a Sunderland third-degree injury, characterized by gradual, incomplete recovery without intervention.

Systematic variation of prosthetic foot spring affects center-of-mass mechanics and metabolic cost during walking.

PubMed

Zelik, Karl E; Collins, Steven H; Adamczyk, Peter G; Segal, Ava D; Klute, Glenn K; Morgenroth, David C; Hahn, Michael E; Orendurff, Michael S; Czerniecki, Joseph M; Kuo, Arthur D

2011-08-01

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the controlled energy storage and return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return, and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy. © 2011 IEEE

Systematic variation of prosthetic foot spring affects center-of-mass mechanics and metabolic cost during walking

PubMed Central

Zelik, Karl E.; Collins, Steven H.; Adamczyk, Peter G.; Segal, Ava D.; Klute, Glenn K.; Morgenroth, David C.; Hahn, Michael E.; Orendurff, Michael S.; Czerniecki, Joseph M.; Kuo, Arthur D.

2014-01-01

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the Controlled Energy Storage and Return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy. PMID:21708509

Electrical stimulation of transplanted motoneurons improves motor unit formation

PubMed Central

Liu, Yang; Grumbles, Robert M.

2014-01-01

Motoneurons die following spinal cord trauma and with neurological disease. Intact axons reinnervate nearby muscle fibers to compensate for the death of motoneurons, but when an entire motoneuron pool dies, there is complete denervation. To reduce denervation atrophy, we have reinnervated muscles in Fisher rats from local transplants of embryonic motoneurons in peripheral nerve. Since growth of axons from embryonic neurons is activity dependent, our aim was to test whether brief electrical stimulation of the neurons immediately after transplantation altered motor unit numbers and muscle properties 10 wk later. All surgical procedures and recordings were done in anesthetized animals. The muscle consequences of motoneuron death were mimicked by unilateral sciatic nerve section. One week later, 200,000 embryonic day 14 and 15 ventral spinal cord cells, purified for motoneurons, were injected into the tibial nerve 10–15 mm from the gastrocnemii muscles as the only neuron source for muscle reinnervation. The cells were stimulated immediately after transplantation for up to 1 h using protocols designed to examine differential effects due to pulse number, stimulation frequency, pattern, and duration. Electrical stimulation that included short rests and lasted for 1 h resulted in higher motor unit counts. Muscles with higher motor unit counts had more reinnervated fibers and were stronger. Denervated muscles had to be stimulated directly to evoke contractions. These results show that brief electrical stimulation of embryonic neurons, in vivo, has long-term effects on motor unit formation and muscle force. This muscle reinnervation provides the opportunity to use patterned electrical stimulation to produce functional movements. PMID:24848463

Visualization of Heart Rate Variability of Long-Term Heart Transplant Patient by Transition Networks: A Case Report.

PubMed

Wdowczyk, Joanna; Makowiec, Danuta; Dorniak, Karolina; Gruchała, Marcin

2016-01-01

We present a heart transplant patient at his 17th year of uncomplicated follow-up. Within a frame of routine check out several tests were performed. With such a long and uneventful follow-up some degree of graft reinnervation could be anticipated. However, the patient's electrocardiogram and exercise parameters seemed largely inconclusive in this regard. The exercise heart rate dynamics were suggestive of only mild, if any parasympathetic reinnervation of the graft with persisting sympathetic activation. On the other hand, traditional heart rate variability (HRV) indices were inadequately high, due to erratic rhythm resulting from interference of the persisting recipient sinus node or non-conducted atrial parasystole. New tools, originated from network representation of time series, by visualization short-term dynamical patterns, provided a method to discern HRV increase due to reinnervation from other reasons.

Application of real-time machine learning to myoelectric prosthesis control: A case series in adaptive switching.

PubMed

Edwards, Ann L; Dawson, Michael R; Hebert, Jacqueline S; Sherstan, Craig; Sutton, Richard S; Chan, K Ming; Pilarski, Patrick M

2016-10-01

Myoelectric prostheses currently used by amputees can be difficult to control. Machine learning, and in particular learned predictions about user intent, could help to reduce the time and cognitive load required by amputees while operating their prosthetic device. The goal of this study was to compare two switching-based methods of controlling a myoelectric arm: non-adaptive (or conventional) control and adaptive control (involving real-time prediction learning). Case series study. We compared non-adaptive and adaptive control in two different experiments. In the first, one amputee and one non-amputee subject controlled a robotic arm to perform a simple task; in the second, three able-bodied subjects controlled a robotic arm to perform a more complex task. For both tasks, we calculated the mean time and total number of switches between robotic arm functions over three trials. Adaptive control significantly decreased the number of switches and total switching time for both tasks compared with the conventional control method. Real-time prediction learning was successfully used to improve the control interface of a myoelectric robotic arm during uninterrupted use by an amputee subject and able-bodied subjects. Adaptive control using real-time prediction learning has the potential to help decrease both the time and the cognitive load required by amputees in real-world functional situations when using myoelectric prostheses. © The International Society for Prosthetics and Orthotics 2015.

A descriptive study of traumatic lower limb amputees from the Hospital Hel Trabajador: clinical evolution from the accident until rehabilitation discharge.

PubMed

Rotter, Karin; Sanhueza, Roberto; Robles, Karina; Godoy, Marcela

2006-04-01

The purpose of the study was to describe the demographics, the causes of amputations, the amputation levels, the clinical outcomes, the durability of prostheses in unilateral lower limb amputee among workers entitled to non-state related work insurance, the ACHS, Chile, between 1974 and 2001. It was a retrospective descriptive study based on selected clinical files. One hundred files, with the minimal data required, were selected with a diagnosis of traumatic lower limb amputation, the levels ranging from Boyd's foot amputation to hip disarticulation, as defined by the Occupational Accidents Act from 1974 to December 2001. The mean age was 35.5 years, 96% were males, with an average follow-up of 7.7 years. In 50% of the cases the education level did not exceed elementary school. Ninety-eight percent were blue collar workers. The traumatic injury resulting in amputation took place during work in 89% of the cases the main causes being crushing injury (50%), traffic accident (19%), run over by car (14%) and burns (6%). The most common amputation levels were trans-femoral (40%) and trans-tibial (47%). Amputations were performed within the first 24 h in 49% of the cases. The hospitalization stay reached 8 weeks in 56.7%. Early complications were dehiscence (9.4%), superficial infection, (14.6%) and deep infection (26%). Late complications detected were soft tissue lesions (34.1%), exostosis (3.6%), painful neuroma (12.5%) and phantom limb pain (12.5%). Prostheses durability was on average 3 years. The average period to resume work was 1 year for 60% of the cases.

Administration for Community Living

MedlinePlus

... has been awarded under the… read more New robotic hand named after Luke Skywalker helps amputee touch ... November 15, 2017 Washington Post (November 15) New robotic hand named after Luke Skywalker helps amputee touch ...

Prosthetic Engineering

MedlinePlus

... torque adapter in the pylons of transtibial amputees. Energy Storage & Release Many ambulatory lower limb amputees exhibit ... Future Directions Current Project Summaries Development of Controlled Energy Storage and Release Prosthetic Foot Development of Inverting- ...

Cortical Reorganization in Dual Innervation by Single Peripheral Nerve.

PubMed

Zheng, Mou-Xiong; Shen, Yun-Dong; Hua, Xu-Yun; Hou, Ao-Lin; Zhu, Yi; Xu, Wen-Dong

2017-09-21

Functional recovery after peripheral nerve injury and repair is related with cortical reorganization. However, the mechanism of innervating dual targets by 1 donor nerve is largely unknown. To investigate the cortical reorganization when the phrenic nerve simultaneously innervates the diaphragm and biceps. Total brachial plexus (C5-T1) injury rats were repaired by phrenic nerve-musculocutaneous nerve transfer with end-to-side (n = 15) or end-to-end (n = 15) neurorrhaphy. Brachial plexus avulsion (n = 5) and sham surgery (n = 5) rats were included for control. Behavioral observation, electromyography, and histologic studies were used for confirming peripheral nerve reinnervation. Cortical representations of the diaphragm and reinnervated biceps were studied by intracortical microstimulation techniques before and at months 0.5, 3, 5, 7, and 10 after surgery. At month 0.5 after complete brachial plexus injury, the motor representation of the injured forelimb disappeared. The diaphragm representation was preserved in the "end-to-side" group but absent in the "end-to-end" group. Rhythmic contraction of biceps appeared in "end-to-end" and "end-to-side" groups, and the biceps representation reappeared in the original biceps and diaphragm areas at months 3 and 5. At month 10, it was completely located in the original biceps area in the "end-to-end" group. Part of the biceps representation remained in the original diaphragm area in the "end-to-side" group. Destroying the contralateral motor cortex did not eliminate respiration-related contraction of biceps. The brain tends to resume biceps representation from the original diaphragm area to the original biceps area following phrenic nerve transfer. The original diaphragm area partly preserves reinnervated biceps representation after end-to-side transfer. Copyright © 2017 by the Congress of Neurological Surgeons

Intention detection of gait initiation using EMG and kinematic data.

PubMed

Wentink, E C; Beijen, S I; Hermens, H J; Rietman, J S; Veltink, P H

2013-02-01

Gait initiation in transfemoral amputees (TFA) is different from non-amputees. This is mainly caused by the lack of stability and push-off from the prosthetic leg. Adding control and artificial push-off to the prosthesis may therefore be beneficial to TFA. In this study the feasibility of real-time intention detection of gait initiation was determined by mimicking the TFA situation in non-amputees. EMG and inertial sensor data was measured in 10 non-amputees. Only data available in TFA was used to determine if gait initiation can be predicted in time to control a transfemoral prosthesis to generate push-off and stability. Toe-off and heel-strike of the leading limb are important parameters to be detected, to control a prosthesis and to time push-off. The results show that toe-off and heel-strike of the leading limb can be detected using EMG and kinematic data in non-amputees 130-260 ms in advance. This leaves enough time to control a prosthesis. Based on these results we hypothesize that similar results can be found in TFA, allowing for adequate control of a prosthesis during gait initiation. Copyright © 2012 Elsevier B.V. All rights reserved.

Kinematics in the terminal swing phase of unilateral transfemoral amputees: microprocessor-controlled versus swing-phase control prosthetic knees.

PubMed

Mâaref, Khaled; Martinet, Noël; Grumillier, Constance; Ghannouchi, Slaheddine; André, Jean Marie; Paysant, Jean

2010-06-01

To analyze the spatiotemporal parameters in the terminal swing phase of the prosthetic limb in unilateral transfemoral amputees (TFAs) compared with a group of asymptomatic subjects, and to identify a latency period (LP) in the TFA between the full extension of the prosthetic knee and the initial ground contact of the ipsilateral foot. To study the correlation between the LP and the duration of the swing phase. To evaluate the influence of the type of knee, the time since amputation, and the amputation level on the latency period. Three-dimensional gait analysis with an optoelectronic device. Gait analysis laboratory of a re-education and functional rehabilitation service. TFA (n=29) and able-bodied (n=15) subjects. Not applicable. Spatiotemporal and kinematics gait parameters. The swing phase and the LP of the prosthetic limb, associated with a consequently longer single-limb stance phase in the intact limb, were significantly longer than those measured in the intact limbs of these subjects, as well as those measured on both lower limbs of the able-bodied subjects (P<.05). There is a positive correlation (P<.05; r(2)=.58 between the LP and the swing phase on the TFA's prosthetic side. The LP measured in the prosthetic limb of TFA with a swing-phase control prosthetic knee is significantly greater than in those using the microprocessor-controlled prosthetic knee (P<.05). Of negligible duration in able-bodied subjects and in the intact limb of TFA, the LP is significantly greater in the prosthetic limb. It can explain the lengthened swing phase on the prosthetic side of those subjects. The use of a microprocessor-controlled prosthetic knee allows the LP to be reduced. This LP appears to be necessary to insure the stability of the prosthetic knee. We suggest calling this time "confidence time." Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Nerve-dependent changes in skeletal muscle myosin heavy chain after experimental denervation and cross-reinnervation and in a demyelinating mouse model of Charcot-Marie-Tooth disease type 1A.

PubMed

Maggs, Alison M; Huxley, Clare; Hughes, Simon M

2008-12-01

Innervation regulates the contractile properties of vertebrate muscle fibers, in part through the effect of electrical activity on expression of distinct myosins. Herein we analyze the role of innervation in regulating the accumulation of the general, maturational, and adult forms of rodent slow myosin heavy chain (MyHC) that are defined by the presence of distinct antigenic epitopes. Denervation increases the number of fibers that express general slow MyHC, but it decreases the adult slow MyHC epitope. Cross-reinnervation of slow muscle by a fast nerve leads to an increase in the number of fibers that express fast MyHC. In both cases, there is an increase in the number of fibers that express slow and fast IIA MyHCs, but without the adult slow MyHC epitope. The data suggest that innervation is required for maturation and maintenance of diversity of both slow and fast fibers. The sequence of slow MyHC epitope transitions is a useful biomarker, and it may play a significant role during nerve-dependent changes in muscle fiber function. We applied this detailed muscle analysis to a transgenic mouse model of human motor and sensory neuropathy IA, also known as Charcot-Marie-Tooth disease type 1A (CMT1A), in which electrical conduction in some motor nerves is poor due to demyelination. The mice display atrophy of some muscle fibers and changes in slow and fast MyHC epitope expression, suggestive of a progressive increase in innervation of muscle fibers by fast motor neurons, even at early stages. The potential role of these early changes in disease pathogenesis is assessed.

Remodeling of motor units after nerve regeneration studied by quantitative electromyography.

PubMed

Krarup, Christian; Boeckstyns, Michel; Ibsen, Allan; Moldovan, Mihai; Archibald, Simon

2016-02-01

Peripheral nerve has the capacity to regenerate after nerve lesions; during reinnervation of muscle motor units are gradually reestablished. The aim of this study was to follow the time course of reestablishing and remodeling of motor units in relation to recovery of force after different types of nerve repair. Reinnervation of muscle was compared clinically and electrophysiologically in complete median or ulnar nerve lesions with short gap lengths in the distal forearm repaired with a collagen nerve conduit (11 nerves) or nerve suture (10 nerves). Reestablishment of motor units was studied by quantitative EMG and recording of evoked compound muscle action potential (CMAP) during a 24-month observation period after nerve repair. Force recovered partially to about 80% of normal. Denervation activity gradually decreased during reinnervation though it was still increased at 24 months. Nascent motor unit potentials (MUPs) at early reinnervation were prolonged and polyphasic. During longitudinal studies, MUPs remained prolonged and their amplitudes gradually increased markedly. Firing of MUPs was unstable throughout the study. CMAPs gradually increased and the number of motor units recovered to approximately 20% of normal. There was weak evidence of CMAP amplitude recovery after suture ahead of conduit repair but without treatment related differences at 2 years. Surgical repair of nerve lesions with a nerve conduit or suture supported recovery of force and of motor unit reinnervation to the same extent. Changes occurred at a higher rate during early regeneration and slower after 12 months but should be followed for at least 2 years to assess outcome. EMG changes reflected extensive remodeling of motor units from early nascent units to a mature state with greatly enlarged units due to axonal regeneration and collateral sprouting and maturation of regenerated nerve and reinnervated muscle fibers after both types of repair. Remodeling of motor units after peripheral nerve

Phantom radiculitis effectively treated by fluoroscopically guided transforaminal epidural steroid injections.

PubMed

DeGregoris, Gerard; Diwan, Sudhir

2010-01-01

Lower back and extremity pain in the amputee patient can be challenging to classify and treat. Radicular compression in a patient with lower limb amputation may present as or be superimposed upon phantom limb pain, creating diagnostic difficulties. Both patients and physicians classically find it difficult to discern phantom sensation from phantom limb pain and stump pain; radicular compression is often not considered. Many studies have shown back pain to be a significant cause of pain in lower limb amputees, but sciatica has been rarely reported in amputees. We present a case of L4/5 radiculitis in an above-knee amputee presenting as phantom radiculitis. Our patient is a 67 year old gentleman with new onset 10/10 pain in a phantom extremity superimposed upon a 40 year history of previously stable phantom limb pain. MRI showed a central disc herniation at L4/5 with compression of the traversing left L4 nerve root. Two fluoroscopically guided left transforaminal epidural steroid injections at the level of the L4 and L5 spinal nerve roots totally alleviated his new onset pain. At one year post injection, his phantom radiculitis pain was completely gone, though his underlying phantom limb pain remained. Lumbar radiculitis in lower extremity amputee patients may be difficult to differentiate from baseline phantom limb pain. When conservative techniques fail, fluoroscopically guided spinal nerve injection may be valuable in determining the etiology of lower extremity pain. Our experience supports the notion that epidural steroid injections can effectively treat phantom lumbar radiculitis in lower extremity amputees.

Surveying the interest of individuals with upper limb loss in novel prosthetic control techniques.

PubMed

Engdahl, Susannah M; Christie, Breanne P; Kelly, Brian; Davis, Alicia; Chestek, Cynthia A; Gates, Deanna H

2015-06-13

Novel techniques for the control of upper limb prostheses may allow users to operate more complex prostheses than those that are currently available. Because many of these techniques are surgically invasive, it is important to understand whether individuals with upper limb loss would accept the associated risks in order to use a prosthesis. An online survey of individuals with upper limb loss was conducted. Participants read descriptions of four prosthetic control techniques. One technique was noninvasive (myoelectric) and three were invasive (targeted muscle reinnervation, peripheral nerve interfaces, cortical interfaces). Participants rated how likely they were to try each technique if it offered each of six different functional features. They also rated their general interest in each of the six features. A two-way repeated measures analysis of variance with Greenhouse-Geisser corrections was used to examine the effect of the technique type and feature on participants' interest in each technique. Responses from 104 individuals were analyzed. Many participants were interested in trying the techniques - 83 % responded positively toward myoelectric control, 63 % toward targeted muscle reinnervation, 68 % toward peripheral nerve interfaces, and 39 % toward cortical interfaces. Common concerns about myoelectric control were weight, cost, durability, and difficulty of use, while the most common concern about the invasive techniques was surgical risk. Participants expressed greatest interest in basic prosthesis features (e.g., opening and closing the hand slowly), as opposed to advanced features like fine motor control and touch sensation. The results of these investigations may be used to inform the development of future prosthetic technologies that are appealing to individuals with upper limb loss.

Deficient functional recovery after facial nerve crush in rats is associated with restricted rearrangements of synaptic terminals in the facial nucleus.

PubMed

Hundeshagen, G; Szameit, K; Thieme, H; Finkensieper, M; Angelov, D N; Guntinas-Lichius, O; Irintchev, A

2013-09-17

Crush injuries of peripheral nerves typically lead to axonotmesis, axonal damage without disruption of connective tissue sheaths. Generally, human patients and experimental animals recover well after axonotmesis and the favorable outcome has been attributed to precise axonal reinnervation of the original peripheral targets. Here we assessed functionally and morphologically the long-term consequences of facial nerve axonotmesis in rats. Expectedly, we found that 5 months after crush or cryogenic nerve lesion, the numbers of motoneurons with regenerated axons and their projection pattern into the main branches of the facial nerve were similar to those in control animals suggesting precise target reinnervation. Unexpectedly, however, we found that functional recovery, estimated by vibrissal motion analysis, was incomplete at 2 months after injury and did not improve thereafter. The maximum amplitude of whisking remained substantially, by more than 30% lower than control values even 5 months after axonotmesis. Morphological analyses showed that the facial motoneurons ipsilateral to injury were innervated by lower numbers of glutamatergic terminals (-15%) and cholinergic perisomatic boutons (-26%) compared with the contralateral non-injured motoneurons. The structural deficits were correlated with functional performance of individual animals and associated with microgliosis in the facial nucleus but not with polyinnervation of muscle fibers. These results support the idea that restricted CNS plasticity and insufficient afferent inputs to motoneurons may substantially contribute to functional deficits after facial nerve injuries, possibly including pathologic conditions in humans like axonotmesis in idiopathic facial nerve (Bell's) palsy. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Using virtual reality environment to facilitate training with advanced upper-limb prosthesis.

PubMed

Resnik, Linda; Etter, Katherine; Klinger, Shana Lieberman; Kambe, Charles

2011-01-01

Technological advances in upper-limb prosthetic design offer dramatically increased possibilities for powered movement. The DEKA Arm system allows users 10 powered degrees of movement. Learning to control these movements by utilizing a set of motions that, in most instances, differ from those used to obtain the desired action prior to amputation is a challenge for users. In the Department of Veterans Affairs "Study to Optimize the DEKA Arm," we attempted to facilitate motor learning by using a virtual reality environment (VRE) program. This VRE program allows users to practice controlling an avatar using the controls designed to operate the DEKA Arm in the real world. In this article, we provide highlights from our experiences implementing VRE in training amputees to use the full DEKA Arm. This article discusses the use of VRE in amputee rehabilitation, describes the VRE system used with the DEKA Arm, describes VRE training, provides qualitative data from a case study of a subject, and provides recommendations for future research and implementation of VRE in amputee rehabilitation. Our experience has led us to believe that training with VRE is particularly valuable for upper-limb amputees who must master a large number of controls and for those amputees who need a structured learning environment because of cognitive deficits.

Long-term recovery of muscle strength after denervation in the fibular division of the sciatic nerve.

PubMed

Stefancic, Martin; Vidmar, Gaj; Blagus, Rok

2016-10-01

The probability and degree of muscle recovery after lesions of long peripheral nerves have not been assessed quantitatively. Twelve adults with closed injuries of the fibular division of the sciatic nerve with complete denervation of associated muscles were followed-up for 2-10 years. The onset of reinnervation was detected electromyographically. Calf circumference and maximum voluntary isometric contraction (MVIC) of foot dorsiflexion were measured on both sides during 2-4 visits. Reinnervation occurred in 11 patients after an average of 13 months. MVIC on the affected side was 2%-27% of that on the unaffected side (average 11%) and remained stable for the following 2-3 years. Correlations and mixed-model regressions confirmed that the degree of recovery was negatively associated with duration of denervation. Reinnervation occurs in about 90% of patients within about 1 year. About 10% of baseline dorsiflexion strength is permanently recovered, which is functionally relevant. Muscle Nerve, 2016 Muscle Nerve 54: -, 2016 Muscle Nerve 54: 702-708, 2016. © 2016 Wiley Periodicals, Inc.

From research to self-reflection: learning about ourselves as academics through a support group's resistance to our intervention.

PubMed

Scherr, Courtney Lynam; Mattson, Marifran

2012-01-01

Purdue University's Center for Healthcare Engineering developed a computer-assisted technology hub (CATHUB) designed to aid individuals with disabilities. Upon realizing the lack of input from the very individuals they were trying to help, Marifran approached the developers of CATHUB and offered to engage a group of amputees to aid in the design and implementation of the hub. In this essay, Courtney and Marifran recount, each from their own perspective, their experiences working with Amputees in Action as participants in their research project. Ultimately the researchers discovered their research agenda was not compatible with the amputees' needs, resulting in enlightened self-reflection by the researchers and abandonment of the research project.

Alterations in the Local Axonal Environment Influence Target Reinnervation and Neuronal Survival After PostnataI Axotomy

DTIC Science & Technology

2000-06-21

2000 Dissertation directed by: Rosemary C. Borke, Ph.D. Professor Department of Anatomy and Cell Biology Following peripheral nerve injury in adult...augmented at the injury site and the neuromuscular junction (NMJ) following sciatic nerve axotomy. The current work determined that SC apoptosis occurs in...related and location-specific response to peripheral nerve injury . Apoptotic SC were found in two strategic locations for guiding axonal outgrowth during

[Apoptosis and expression of apoptosis-related proteins in experimental different denervated guinea-pig facial muscle].

PubMed

Hui, Lian; Wei, Hong-Quan; Li, Xiao-Tian; Guan, Chao; Ren, Zhong

2005-02-01

To study apoptosis and expression of apoptosis-related proteins in experimental different denervated guinea-pig facial muscle. An experimental model was established with guinea pigs by compressing the facial nerve 30 second (reinnervated group) and resecting the facial nerve (denervated group). TUNEL method and immunohistochemical technique (SABC) were applied to detect the apoptosis and expression of apoptosis-related proteins bcl-2 and bax from 1st to 8th week after operation. Experimentally denervated facial muscle revealed consistently increase of DNA fragmentation, average from(34.4 +/- 4.6)% to (38.2 +/- 10.6)%, from 1st week to 8th week after operation; Reinnervated facial muscle showed a temporal increase of DNA fragmentation, and then the muscle fiber nuclei revealed decreased DNA fragmentation along with the function of facial nerve recovered, latterly normal, average from (32.0 +/- 8.03)% to (5.6 +/- 3.5)%, from 1st week to 8th week after operation. In denervated group, bcl-2 and bax were expressed strongly; in reinnervated group, bcl-2 expressed consistently, but bax disappeared latterly along with the function of facial nerve recovered. Expression of DNA fragmentation and apoptosis-related proteins in denervated muscle are general reaction to denervation. bcl-2 can prevent early apoptotic muscle fiber to survival until reinnervation. It is concluded that proteins control apoptosis may give information for possible therapeutic interventions to reduce the rate of muscle fiber death in denervated atrophy in absence of effective primary treatment.

The masseteric nerve: a versatile power source in facial animation techniques.

PubMed

Bianchi, B; Ferri, A; Ferrari, S; Copelli, C; Salvagni, L; Sesenna, E

2014-03-01

The masseteric nerve has many advantages including low morbidity, its proximity to the facial nerve, the strong motor impulse, its reliability, and the fast reinnervation that is achievable in most patients. Reinnervation of a neuromuscular transplant is the main indication for its use, but it has been used for the treatment of recent facial palsies with satisfactory results. We have retrospectively evaluated 60 patients who had facial animation procedures using the masseteric nerve during the last 10 years. The patients included those with recent, and established or congenital, unilateral and bilateral palsies. The masseteric nerve was used for coaptation of the facial nerve either alone or in association with crossfacial nerve grafting, or for the reinnervation of gracilis neuromuscular transplants. Reinnervation was successful in all cases, the mean (range) time being 4 (2-5) months for facial nerve coaptation and 4 (3-7) months for neuromuscular transplants. Cosmesis was evaluated (moderate, n=10, good, n=30, and excellent, n=20) as was functional outcome (no case of impairment of masticatory function, all patients able to smile, and achievement of a smile independent from biting). The masseteric nerve has many uses, including in both recent, and established or congenital, cases. In some conditions it is the first line of treatment. The combination of combined techniques gives excellent results in unilateral palsies and should therefore be considered a valid option. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Development of Subischial Prosthetic Sockets with Vacuum-Assisted Suspension for Highly Active Persons with Transfemoral Amputations

DTIC Science & Technology

2015-10-01

2011;92:1570– 1575 . 12. Ferraro C. Outcomes study of transtibial amputees using elevated vacuum suspension in comparison with pin suspension. J Prosthet...Amputees: Effect on Fit, Activity, and Limb Volume,” Arch. Phys. Med. Rehabil., 92(10), pp. 1570– 1575 . [6] Hoskins, R. D., Sutton, E. E., Kinor, D

Selective Radiofrequency Stimulation of the Dorsal Root Ganglion (DRG) as a Method for Predicting Targets for Neuromodulation in Patients With Post Amputation Pain: A Case Series.

PubMed

Hunter, Corey W; Yang, Ajax; Davis, Tim

2017-10-01

While spinal cord stimulation (SCS) has established itself as an accepted and validated treatment for neuropathic pain, there are a number of conditions where it has experienced less, long-term success: post amputee pain (PAP) being one of them. Dorsal root ganglion (DRG) stimulation has shown great promise, particularly in conditions where traditional SCS has fallen short. One major difference between DRG stimulation and traditional SCS is the ability to provide focal stimulation over targeted areas. While this may be a contributing factor to its superiority, it can also be a limitation insofar stimulating the wrong DRG(s) can lead to failure. This is particularly relevant in conditions like PAP where neuroplastic maladaptation occurs causing the pain to deviate from expected patterns, thus creating uncertainty and variability in predicting targets for stimulation. We propose selective radiofrequency (RF) stimulation of the DRG as a method for preoperatively predicting targets for neuromodulation in patients with PAP. We present four patients with PAP of the lower extremities. RF stimulation was used to selectively stimulate individual DRG's, creating areas of paresthesias to see which most closely correlated/overlapped with the painful area(s). RF stimulation to the DRG's that resulted in the desirable paresthesia coverage in the residual or the missing limb(s) was recorded as "positive." Trial DRG leads were placed based on the positive RF stimulation findings. In each patient, stimulating one or more DRG(s) produced paresthesias patterns that were contradictory to know dermatomal patterns. Upon completion of a one-week trial all four patients reported 60-90% pain relief, with coverage over the painful areas, and opted for permanent implant. Mapping the DRG via RF stimulation appears to provide improved accuracy for determining lead placement in the setting of PAP where pain patterns are known to deviate from conventional dermatomal mapping. © 2017

Time course of functional recovery during the first 3 mo after surgical transection and repair of nerves to the feline soleus and lateral gastrocnemius muscles.

PubMed

Gregor, Robert J; Maas, Huub; Bulgakova, Margarita A; Oliver, Alanna; English, Arthur W; Prilutsky, Boris I

2018-03-01

Locomotion outcomes after peripheral nerve injury and repair in cats have been described in the literature for the period immediately following the injury (muscle denervation period) and then again for an ensuing period of long-term recovery (at 3 mo and longer) resulting in muscle self-reinnervation. Little is known about the changes in muscle activity and walking mechanics during midrecovery, i.e., the early reinnervation period that takes place between 5 and 10 wk of recovery. Here, we investigated hindlimb mechanics and electromyogram (EMG) activity of ankle extensors in six cats during level and slope walking before and every 2 wk thereafter in a 14-wk period of recovery after the soleus (SO) and lateral gastrocnemius (LG) muscle nerves in one hindlimb were surgically transected and repaired. We found that the continued increase in SO and LG EMG magnitudes and corresponding changes in hindlimb mechanics coincided with the formation of neuromuscular synapses revealed in muscle biopsies. Throughout the recovery period, EMG magnitude of SO and LG during the stance phase and the duration of the stance-related activity were load dependent, similar to those in the intact synergistic medial gastrocnemius and plantaris. These results and the fact that EMG activity of ankle extensors and locomotor mechanics during level and upslope walking recovered 14 wk after nerve transection and repair suggest that loss of the stretch reflex in self-reinnervated muscles may be compensated by the recovered force-dependent feedback in self-reinnervated muscles, by increased central drive, and by increased gain in intermuscular motion-dependent pathways from intact ankle extensors. NEW & NOTEWORTHY This study provides new evidence that the timeline for functional recovery of gait after peripheral nerve injury and repair is consistent with the time required for neuromuscular junctions to form and muscles to reach preoperative tensions. Our findings suggest that a permanent loss of

Scapular resting position, shoulder pain and function in disabled athletes.

PubMed

Aytar, Aydan; Zeybek, Aslican; Pekyavas, Nihan Ozunlu; Tigli, Ayca Aytar; Ergun, Nevin

2015-10-01

Despite the fact that the number of disabled individuals participating in sports is increasing, there are only sparse reports in the literature concerning overuse injuries. The purpose of this study was to compare scapular resting position, shoulder pain, and function in wheelchair basketball, amputee soccer, and disabled table tennis players. Descriptive study. A total of 63 disabled players from amputee soccer, wheelchair basketball, and disabled table tennis participated in our study. Scapular resting position was taken as primary outcome; pain and function were taken as secondary outcome measurements. Scapular resting position was evaluated with Lateral Scapular Slide Test. Visual Analog Scale was used for evaluating shoulder pain intensity. Quick disabilities of the arm, shoulder, and hand questionnaire were used to assess upper extremity function. There was a significant difference in shoulder pain, function, and scapular resting position in all groups (p < 0.05). Paired comparisons between amputee soccer and wheelchair basketball players and also amputee soccer and disabled table tennis showed difference for all measurement parameters (p < 0.05). When the results are evaluated, it may be stated that amputee soccer players have better scapular resting position than other sports. Crutch usage may not negatively affect scapular resting position and perceived function as much as wheelchair usage. Exercise techniques for shoulder and resting position could be included in training programs of disabled athletes. Wheelchair/crutch usage is a risk, and special exercise techniques for shoulder and dyskinesis could be included in training programs to prevent injury. However, it may not just be important for wheelchair athletes, it may also be important for amputee soccer players. In particular, total upper extremity evaluations and exercises could be added within exercise programs. © The International Society for Prosthetics and Orthotics 2014.

Amputations in the burn unit: A retrospective analysis of 82 patients across 12 years.

PubMed

Li, Quan; Wang, Ling-Feng; Chen, Qiang; Wang, Shu-Jie; Li, Fang; Ba, Te

2017-11-01

The aim of this study is to analyze the data of amputees in the burn center of the Inner Mongolia region and to provide instructive suggestions for a preventative reduction of the amputation rate. Between 2004 and 2016, all patient medical profiles were reviewed to extract data of patients with major amputation. Demographic data, mechanism of injury, location and level of amputation were recorded. The healing condition of the residual limb was noted. In addition, we performed comparisons of amputees whose injuries were caused by electricity and those whose injuries were related to other mechanisms. Among the 82 amputees in our study, about 89% of amputees were male patients and the predominant age-group was 20-29 years (26.8%). The injuries occurred most commonly at the work place (62.2%) with laborers (40.2%) being the most commonly affected. The most common mechanisms of injury were electricity (51.2%) and hot crush (14.6%), followed by frostbite (13.4%). The most common level of amputation was the right wrist joint (n=16). About 60.4% of the amputation sites were by primary healing. The rate of escharotomy in electrical burn amputees (n=27, 62.3%) was significantly higher than the other groups (n=16, 40.0%, p<0.05). The first amputation in electrical burn group (7.2±5.6) was significantly earlier than the other etiology group (17.9±13.7, p<0.05). Electrical burns were the major mechanism of injury among amputees. Effective safety measures, factory modifications, and adequate instructions should be implemented to protect laborers. Urgent interdisciplinary communication should be taken into account for the prevention reduction of the amputation rate in our region. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Prosthetic helping hand

NASA Technical Reports Server (NTRS)

Vest, Thomas W. (Inventor); Carden, James R. (Inventor); Norton, William E. (Inventor); Belcher, Jewell G. (Inventor)

1992-01-01

A prosthetic device for below-the-elbow amputees, having a C-shaped clamping mechanism for grasping cylindrical objects, is described. The clamping mechanism is pivotally mounted to a cuff that fits on the amputee's lower arm. The present invention is utilized by placing an arm that has been amputated below the elbow into the cuff. The clamping mechanism then serves as a hand whenever it becomes necessary for the amputee to grasp a cylindrical object such as a handle, a bar, a rod, etc. To grasp the cylindrical object, the object is jammed against the opening in the C-shaped spring, causing the spring to open, the object to pass to the center of the spring, and the spring to snap shut behind the object. Various sizes of clamping mechanisms can be provided and easily interchanged to accommodate a variety of diameters. With the extension that pivots and rotates, the clamping mechanism can be used in a variety of orientations. Thus, this invention provides the amputee with a clamping mechanism that can be used to perform a number of tasks.

Individual responses to alignment perturbations in socket reaction moments while walking in transtibial prostheses.

PubMed

Kobayashi, Toshiki; Orendurff, Michael S; Zhang, Ming; Boone, David A

2014-05-01

The alignment of transtibial prostheses has a systematic effect on the mean socket reaction moments in amputees. However, understanding their individual differences in response to alignment perturbations is also important for prosthetists to fully utilize the socket reaction moments for dynamic alignment in each unique patient. The aim of this study was to investigate individual responses to alignment perturbations in transtibial prostheses with solid-ankle-cushion-heel feet. A custom instrumented prosthesis alignment component was used to measure the socket reaction moments while walking in 11 amputees with transtibial prostheses under 17 alignment conditions, including 3° and 6° of flexion, extension, abduction, and adduction of the socket, 5mm and 10mm of anterior, posterior, lateral, and medial translation of the socket, and an initial baseline alignment. Coronal moments at 30% of stance and maximum sagittal moments were extracted for comparisons from each amputee. In the coronal plane, varus moment at 30% of stance was generally reduced by adduction or medial translation of the socket in all the amputees. In the sagittal plane, extension moment was generally increased by posterior translation or flexion of the socket; however, this was not necessarily the case for all the amputees. Individual responses to alignment perturbations are not always consistent, and prosthetists would need to be aware of this variance when addressing individual socket reaction moments during dynamic alignment in clinical setting. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exploring ethical justification for self-demand amputation.

PubMed

Tomasini, Floris

2006-01-01

Self-demand amputees are persons who need to have one or more healthy limbs or digits amputated to fit the way they see themselves. They want to rid themselves of a limb that they believe does not belong to their body-identity. The obsessive desire to have appendages surgically removed to fit an alternative body-image is medically and ethically controversial. My purpose in this paper is to provide a number of normative and professional ethical perspectives on whether or not it is possible to justify surgery for self-demand amputees. In doing so I proceed dialogically, moving between empirical context and normative theory, revealing the taken for granted normative assumptions (what I call the natural attitude--a technical term borrowed from phenomenology) that provide ethical limits to justifying the treatment of self-demand amputees. While I critically examine both Kantian responses against as well as Utilitarian responses for amputation on demand, I conclude that neither normative tradition can fully incorporate an understanding of what it is like to be a self-demand amputee. Since neither theory can justify the apparent non-rational desire of amputation on demand, ethical justification, I argue, falls short of the recognition that there may be a problem. To end, I introduce a meta-ethical idea, "the struggle for recognition," opening up the theoretical possibility of a hermeneutics of recognition before ethical justification that may be more sensitive to the problem of radical embodied difference exemplified by self-demand amputees.

Motor Cortex Stimulation Regenerative Effects in Peripheral Nerve Injury: An Experimental Rat Model.

PubMed

Nicolas, Nicolas; Kobaiter-Maarrawi, Sandra; Georges, Samuel; Abadjian, Gerard; Maarrawi, Joseph

2018-06-01

Immediate microsurgical nerve suture remains the gold standard after peripheral nerve injuries. However, functional recovery is delayed, and it is satisfactory in only 2/3 of cases. Peripheral electrical nerve stimulation proximal to the lesion enhances nerve regeneration and muscle reinnervation. This study aims to evaluate the effects of the motor cortex electrical stimulation on peripheral nerve regeneration after injury. Eighty rats underwent right sciatic nerve section, followed by immediate microsurgical epineural sutures. Rats were divided into 4 groups: Group 1 (control, n = 20): no electrical stimulation; group 2 (n = 20): immediate stimulation of the sciatic nerve just proximal to the lesion; Group 3 (n = 20): motor cortex stimulation (MCS) for 15 minutes after nerve section and suture (MCSa); group 4 (n = 20): MCS performed over the course of two weeks after nerve suture (MCSc). Assessment included electrophysiology and motor functional score at day 0 (baseline value before nerve section), and at weeks 4, 8, and 12. Rats were euthanized for histological study at week 12. Our results showed that MCS enhances functional recovery, nerve regeneration, and muscle reinnervation starting week 4 compared with the control group (P < 0.05). The MCS induces higher reinnervation rates even compared with peripheral stimulation, with better results in the MCSa group (P < 0.05), especially in terms of functional recovery. MCS seems to have a beneficial effect after peripheral nerve injury and repair in terms of nerve regeneration and muscle reinnervation, especially when acute mode is used. Copyright © 2018 Elsevier Inc. All rights reserved.

Mirror Therapy and Transcutaneous Electrical Nerve Stimulation for Management of Phantom Limb Pain in Amputees - A Single Blinded Randomized Controlled Trial.

PubMed

Tilak, Merlyn; Isaac, Serin Anna; Fletcher, Jebaraj; Vasanthan, Lenny Thinagaran; Subbaiah, Rajalakshmi Sankaran; Babu, Andrew; Bhide, Rohit; Tharion, George

2016-06-01

Phantom limb pain (PLP) can be disabling for nearly two thirds of amputees. Hence, there is a need to find an effective and inexpensive treatment that can be self administered. Among the non-pharmacological treatment for PLP, transcutaneous electrical nerve stimulation (TENS) applied to the contralateral extremity and mirror therapy are two promising options. However, there are no studies to compare the two treatments. The purpose of this study is to evaluate and compare mirror therapy and TENS in the management of PLP in subjects with amputation. The study was an assessor blinded randomized controlled trial conducted at Physiotherapy Gymnasium of Physical Medicine and Rehabilitation Department, Christian Medical College, Vellore. Twenty-six subjects with PLP consented to participate. An initial assessment of pain using visual analogue scale (VAS) and universal pain score (UPS) was performed by a therapist blinded to the treatment given. Random allocation into Group I-mirror therapy and Group II-TENS was carried out. After 4 days of treatment, pain was re-assessed by the same therapist. The mean difference in Pre and Post values were compared among the groups. The change in pre-post score was analyzed using the paired t test. Participants of Group I had significant decrease in pain [VAS ( p = 0.003) and UPS ( p = 0.001)]. Group II also showed a significant reduction in pain [VAS ( p = 0.003) and UPS ( p = 0.002)]. However, no difference was observed between the two groups [VAS ( p = 0.223 and UPS ( p = 0.956)]. Both Mirror Therapy and TENS were found to be effective in pain reduction on a short-term basis. However, no difference between the two groups was found. Substantiation with long-term follow-up is essential to find its long-term effectiveness. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Heterotopic ossification in civilians with lower limb amputations.

PubMed

Matsumoto, Mary E; Khan, Mohammed; Jayabalan, Prakash; Ziebarth, Jessica; Munin, Michael C

2014-09-01

To report the incidence of symptomatic heterotopic ossification (HO) in a defined civilian amputee population, describe its characteristics, and compare these findings to published data in military amputees. Retrospective chart analysis from July 1998 to July 2009. Ambulatory amputee clinic within a large university medical center. Adults with lower limb amputation (N=158). Not applicable. Patients with symptomatic HO confirmed by radiographs. A total of 261 patients were evaluated; 158 met inclusion criteria, with 59% having traumatic etiology, 18% vascular etiology, 22% infection, and 1% tumor. Symptomatic HO was diagnosed in 36 (22.8%) patients, and 94% patients had mild HO on radiographic scoring. Rate of HO in amputations related to trauma was not increased compared with those of other etiologies. Surgical resection of the ectopic bone was required in 4 (11%) patients. HO is seen commonly after civilian lower limb amputation regardless of etiology. The prevalence was less than that observed in previous reports from military populations. This is the first report estimating the prevalence of HO in adult civilian amputees. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Toward Balance Recovery With Leg Prostheses Using Neuromuscular Model Control

PubMed Central

Geyer, Hartmut

2016-01-01

Objective Lower limb amputees are at high risk of falling as current prosthetic legs provide only limited functionality for recovering balance after unexpected disturbances. For instance, the most established control method used on powered leg prostheses tracks local joint impedance functions without taking the global function of the leg in balance recovery into account. Here we explore an alternative control policy for powered transfemoral prostheses that considers the global leg function and is based on a neuromuscular model of human locomotion. Methods We adapt this model to describe and simulate an amputee walking with a powered prosthesis using the proposed control, and evaluate the gait robustness when confronted with rough ground and swing leg disturbances. We then implement and partially evaluate the resulting controller on a leg prosthesis prototype worn by a non-amputee user. Results In simulation, the proposed prosthesis control leads to gaits that are more robust than those obtained by the impedance control method. The initial hardware experiments with the prosthesis prototype show that the proposed control reproduces normal walking patterns qualitatively and effectively responds to disturbances in early and late swing. However, the response to mid-swing disturbances neither replicates human responses nor averts falls. Conclusions The neuromuscular model control is a promising alternative to existing prosthesis controls, although further research will need to improve on the initial implementation and determine how well these results transfer to amputee gait. Significance This work provides a potential avenue for future development of control policies that help improve amputee balance recovery. PMID:26315935

Transtibial prosthesis suspension systems: systematic review of literature.

PubMed

Gholizadeh, H; Abu Osman, N A; Eshraghi, A; Ali, S; Razak, N A

2014-01-01

Today a number of prosthetic suspension systems are available for transtibial amputees. Consideration of an appropriate suspension system can ensure that amputee's functional needs are satisfied. The higher the insight to suspension systems, the easier would be the selection for prosthetists. This review attempted to find scientific evidence pertaining to various transtibial suspension systems to provide selection criteria for clinicians. Databases of PubMed, Web of Science, and ScienceDirect were explored to find related articles. Search terms were as follows: "Transtibial prosthesis (32), prosthetic suspension (48), lower limb prosthesis (54), below-knee prosthesis (58), prosthetic liner (20), transtibial (193), and prosthetic socket (111)". Two reviewers separately examined the papers. Study design (case series of five or more subjects, retrospective or prospective), research instrument, sampling method, outcome measures and protocols were reviewed. Based on the selection criteria, 22 articles (15 prospective studies, and 7 surveys) remained. Sweat control was found to be a major concern with the available suspension liners. Donning and doffing procedures for soft liners are also problematic for some users, particularly those with upper limb weakness. Moreover, the total surface bearing (TSB) socket with pin/lock system is favored by the majority of amputees. In summary, no clinical evidence is available to suggest what kind of suspension system could have an influential effect as a "standard" system for all transtibial amputees. However, among various suspension systems for transtibial amputees, the Iceross system was favored by the majority of users in terms of function and comfort. © 2013. Published by Elsevier Ltd. All rights reserved.

Role of development in reorganization of the SI forelimb-stump representation in fetally, neonatally, and adult amputated rats.

PubMed

Pluto, Charles P; Lane, Richard D; Chiaia, Nicolas L; Stojic, Andrey S; Rhoades, Robert W

2003-09-01

Rats that sustain forelimb removal on postnatal day (P) 0 exhibit numerous multi-unit recording sites in the forelimb-stump representation of primary somatosensory cortex (SI) that also respond to hindlimb stimulation when cortical GABAA+B receptors are blocked. Most of these hindlimb inputs originate in the medial SI hindlimb representation. Although many forelimb-stump sites in these animals respond to hindlimb stimulation, very few respond to stimulation of the face (vibrissae or lower jaw), which is represented in SI just lateral to the forelimb. The lateral to medial development of SI may influence the capacity of hindlimb (but not face) inputs to "invade" the forelimb-stump region in neonatal amputees. The SI forelimb-stump was mapped in adult (>60 days) rats that had sustained amputation on embryonic day (E) 16, on P0, or during adulthood. GABA receptors were blocked and subsequent mapping revealed increases in nonstump inputs in E16 and P0 amputees: fetal amputees exhibited forelimb-stump sites responsive to face (34%), hindlimb (10%), and both (22%); neonatal amputees exhibited 10% face, 39% hindlimb, and 5% both; adult amputees exhibited 10% face, 5% hindlimb, and 0% both, with approximately 80% stump-only sites. These results indicate age-dependent differences in receptive-field reorganization of the forelimb-stump representation, which may reflect the spatiotemporal development of SI. Results from cobalt chloride inactivation of the SI vibrissae region and electrolesioning of the dysgranular cortex suggest that normally suppressed vibrissae inputs to the SI forelimb-stump area originate in the SI vibrissae region and synapse in the dysgranular cortex.

The recovery of damaged paraspinal muscles by posterior surgical treatment for patients with lumbar degenerative diseases and its clinical consequence.

PubMed

Cha, Jae-Ryong; Kim, Yong-Chan; Yoon, Wan-Keun; Lee, Won-Gyu; Kim, Tae-Hwan; Oh, Jae-Keun; Kim, Seok-Woo; Ohn, Suk Hoon; Cui, Ji Hao

2017-01-01

Posterior lumbar surgery can lead to damage on paraspinal muscles. Our study aimed to examine the recovery in the denervated paraspinal muscles by posterior lumbar surgery and to determine that of improvement in the lower back pain (LBP). Depending on surgical treatments, the patients were divided into two groups: The group I (interspinous implantation with decompression) and II (posterior lumbar interbody fusion with decompression). The paraspinal mapping score was recorded for individual muscle. In the group I, there was reinnervation in the denervated multifidus and erector spinae at the upper, surgical and lower levels at 12 months. In the group II, there was reinnervation in the denervated erector spinae at the upper, surgical and lower levels at 12 months. There was significant aggravation in the LBP in both groups at immediate postoperative. But there was significant improvement in it at 6 months in the group I and at 12 months in the group II. There was reinnervation in not only denervated multifidus and erector spinae at 12 months following interspinous ligament stabilization but also in denervated erector spinae at 12 months following pedicle screw fixation with fusion.

Building a successful support group for post-amputation patients.

PubMed

Marzen-Groller, Karen; Bartman, Kimberly

2005-06-01

The purpose of this article is to identify five steps to attain a successful amputee support group and share the process for establishing and maintaining a peer visitation program for in-patient amputees. Whatever the cause, losing a limb is a life-changing event that one should not go through alone. Support groups can assist patients and their families through this transition in a positive and healthy way.

Stair ascent with an innovative microprocessor-controlled exoprosthetic knee joint.

PubMed

Bellmann, Malte; Schmalz, Thomas; Ludwigs, Eva; Blumentritt, Siegmar

2012-12-01

Climbing stairs can pose a major challenge for above-knee amputees as a result of compromised motor performance and limitations to prosthetic design. A new, innovative microprocessor-controlled prosthetic knee joint, the Genium, incorporates a function that allows an above-knee amputee to climb stairs step over step. To execute this function, a number of different sensors and complex switching algorithms were integrated into the prosthetic knee joint. The function is intuitive for the user. A biomechanical study was conducted to assess objective gait measurements and calculate joint kinematics and kinetics as subjects ascended stairs. Results demonstrated that climbing stairs step over step is more biomechanically efficient for an amputee using the Genium prosthetic knee than the previously possible conventional method where the extended prosthesis is trailed as the amputee executes one or two steps at a time. There is a natural amount of stress on the residual musculoskeletal system, and it has been shown that the healthy contralateral side supports the movements of the amputated side. The mechanical power that the healthy contralateral knee joint needs to generate during the extension phase is also reduced. Similarly, there is near normal loading of the hip joint on the amputated side.

Surgical Interventions for Pediatric Unilateral Vocal Cord Paralysis: A Systematic Review.

PubMed

Butskiy, Oleksandr; Mistry, Bhavik; Chadha, Neil K

2015-07-01

The most widely used surgical interventions for pediatric unilateral vocal cord paralysis include injection laryngoplasty, thyroplasty, and laryngeal reinnervation. Despite increasing interest in surgical interventions for unilateral vocal cord paralysis in children, the surgical outcomes data in children are scarce. To appraise and summarize the available evidence for pediatric unilateral vocal cord paralysis surgical strategies. MEDLINE (1946-2014) and EMBASE (1980-2014) were searched for publications that described the results of laryngoplasty, thyroplasty, or laryngeal reinnervation for pediatric unilateral vocal cord paralysis. Further studies were identified from bibliographies of relevant studies, gray literature, and annual scientific assemblies. Two reviewers independently appraised the selected studies for quality, level of evidence, and risk of bias as well as extracted data, including unilateral vocal cord paralysis origin, voice outcomes, swallowing outcomes, and adverse events. Of 366 identified studies, the inclusion criteria were met by 15 studies: 6 observational studies, 6 case series, and 3 case reports. All 36 children undergoing laryngeal reinnervation (8 studies) had improvement or resolution of dysphonia. Of 31 children receiving injection laryngoplasty (6 studies), most experienced improvement in voice quality, speech, swallowing, aspiration, and glottic closure. Of 12 children treated by thyroplasty (5 studies), 2 experienced resolution of dysphonia, 4 had some improvement, and 4 had no improvement (2 patients had undocumented outcomes). Thyroplasty resolved or improved aspiration in 7 of 8 patients. Published studies suggest that reinnervation may be the most effective surgical intervention for children with dysphonia; however, long-term follow-up data are lacking. With the exception of polytetrafluoroethylene injections, injection laryngoplasty was reported to be a relatively safe, nonpermanent, and effective option for most children with

A real-time comparison between direct control, sequential pattern recognition control and simultaneous pattern recognition control using a Fitts’ law style assessment procedure

PubMed Central

2014-01-01

Background Pattern recognition (PR) based strategies for the control of myoelectric upper limb prostheses are generally evaluated through offline classification accuracy, which is an admittedly useful metric, but insufficient to discuss functional performance in real time. Existing functional tests are extensive to set up and most fail to provide a challenging, objective framework to assess the strategy performance in real time. Methods Nine able-bodied and two amputee subjects gave informed consent and participated in the local Institutional Review Board approved study. We designed a two-dimensional target acquisition task, based on the principles of Fitts’ law for human motor control. Subjects were prompted to steer a cursor from the screen center of into a series of subsequently appearing targets of different difficulties. Three cursor control systems were tested, corresponding to three electromyography-based prosthetic control strategies: 1) amplitude-based direct control (the clinical standard of care), 2) sequential PR control, and 3) simultaneous PR control, allowing for a concurrent activation of two degrees of freedom (DOF). We computed throughput (bits/second), path efficiency (%), reaction time (second), and overshoot (%)) and used general linear models to assess significant differences between the strategies for each metric. Results We validated the proposed methodology by achieving very high coefficients of determination for Fitts’ law. Both PR strategies significantly outperformed direct control in two-DOF targets and were more intuitive to operate. In one-DOF targets, the simultaneous approach was the least precise. The direct control was efficient in one-DOF targets but cumbersome to operate in two-DOF targets through a switch-depended sequential cursor control. Conclusions We designed a test, capable of comprehensively describing prosthetic control strategies in real time. When implemented on control subjects, the test was able to capture

A real-time comparison between direct control, sequential pattern recognition control and simultaneous pattern recognition control using a Fitts' law style assessment procedure.

PubMed

Wurth, Sophie M; Hargrove, Levi J

2014-05-30

Pattern recognition (PR) based strategies for the control of myoelectric upper limb prostheses are generally evaluated through offline classification accuracy, which is an admittedly useful metric, but insufficient to discuss functional performance in real time. Existing functional tests are extensive to set up and most fail to provide a challenging, objective framework to assess the strategy performance in real time. Nine able-bodied and two amputee subjects gave informed consent and participated in the local Institutional Review Board approved study. We designed a two-dimensional target acquisition task, based on the principles of Fitts' law for human motor control. Subjects were prompted to steer a cursor from the screen center of into a series of subsequently appearing targets of different difficulties. Three cursor control systems were tested, corresponding to three electromyography-based prosthetic control strategies: 1) amplitude-based direct control (the clinical standard of care), 2) sequential PR control, and 3) simultaneous PR control, allowing for a concurrent activation of two degrees of freedom (DOF). We computed throughput (bits/second), path efficiency (%), reaction time (second), and overshoot (%)) and used general linear models to assess significant differences between the strategies for each metric. We validated the proposed methodology by achieving very high coefficients of determination for Fitts' law. Both PR strategies significantly outperformed direct control in two-DOF targets and were more intuitive to operate. In one-DOF targets, the simultaneous approach was the least precise. The direct control was efficient in one-DOF targets but cumbersome to operate in two-DOF targets through a switch-depended sequential cursor control. We designed a test, capable of comprehensively describing prosthetic control strategies in real time. When implemented on control subjects, the test was able to capture statistically significant differences (p < 0

Expert opinions on success factors for upper-limb prostheses.

PubMed

Schultz, Aimee E; Baade, Susan P; Kuiken, Todd A

2007-01-01

The goal of this study was to gather the opinions of prosthetics experts on the most important factors for the successful use of upper-limb (UL) prostheses, compare them with those of prosthesis users, and ultimately direct research efforts in this field. UL prosthetics experts were asked to compare the importance of the comfort, function, and cosmesis of a prosthetic device for a transhumeral amputee. Categories were subdivided into weight, socket-interface comfort, power, agility, color, and shape. The majority of those who responded viewed comfort as the most important factor for a unilateral amputee and considered socket-interface comfort to be more important than weight. Function was considered to be the most important factor for a bilateral amputee, with agility considered more important than power. Cosmesis was consistently reported as being less important than comfort and function, and shape was considered more important than color.

Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits.

PubMed

Au, Samuel; Berniker, Max; Herr, Hugh

2008-05-01

The human ankle varies impedance and delivers net positive work during the stance period of walking. In contrast, commercially available ankle-foot prostheses are passive during stance, causing many clinical problems for transtibial amputees, including non-symmetric gait patterns, higher gait metabolism, and poorer shock absorption. In this investigation, we develop and evaluate a myoelectric-driven, finite state controller for a powered ankle-foot prosthesis that modulates both impedance and power output during stance. The system employs both sensory inputs measured local to the external prosthesis, and myoelectric inputs measured from residual limb muscles. Using local prosthetic sensing, we first develop two finite state controllers to produce biomimetic movement patterns for level-ground and stair-descent gaits. We then employ myoelectric signals as control commands to manage the transition between these finite state controllers. To transition from level-ground to stairs, the amputee flexes the gastrocnemius muscle, triggering the prosthetic ankle to plantar flex at terminal swing, and initiating the stair-descent state machine algorithm. To transition back to level-ground walking, the amputee flexes the tibialis anterior muscle, triggering the ankle to remain dorsiflexed at terminal swing, and initiating the level-ground state machine algorithm. As a preliminary evaluation of clinical efficacy, we test the device on a transtibial amputee with both the proposed controller and a conventional passive-elastic control. We find that the amputee can robustly transition between the finite state controllers through direct muscle activation, allowing rapid transitioning from level-ground to stair walking patterns. Additionally, we find that the proposed finite state controllers result in a more biomimetic ankle response, producing net propulsive work during level-ground walking and greater shock absorption during stair descent. The results of this study highlight the

A pressure and shear sensor system for stress measurement at lower limb residuum/socket interface.

PubMed

Laszczak, P; McGrath, M; Tang, J; Gao, J; Jiang, L; Bader, D L; Moser, D; Zahedi, S

2016-07-01

A sensor system for measurement of pressure and shear at the lower limb residuum/socket interface is described. The system comprises of a flexible sensor unit and a data acquisition unit with wireless data transmission capability. Static and dynamic performance of the sensor system was characterised using a mechanical test machine. The static calibration results suggest that the developed sensor system presents high linearity (linearity error ≤ 3.8%) and resolution (0.9 kPa for pressure and 0.2 kPa for shear). Dynamic characterisation of the sensor system shows hysteresis error of approximately 15% for pressure and 8% for shear. Subsequently, a pilot amputee walking test was conducted. Three sensors were placed at the residuum/socket interface of a knee disarticulation amputee and simultaneous measurements were obtained during pilot amputee walking test. The pressure and shear peak values as well as their temporal profiles are presented and discussed. In particular, peak pressure and shear of approximately 58 kPa and 27 kPa, respectively, were recorded. Their temporal profiles also provide dynamic coupling information at this critical residuum/socket interface. These preliminary amputee test results suggest strong potential of the developed sensor system for exploitation as an assistive technology to facilitate socket design, socket fit and effective monitoring of lower limb residuum health. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Mini Review: Biomaterials for Enhancing Neuronal Repair

NASA Astrophysics Data System (ADS)

Cangellaris, Olivia V.; Gillette, Martha U.

2018-04-01

As they differentiate from neuroblasts, nascent neurons become highly polarized and elongate. Neurons extend and elaborate fine and fragile cellular extensions that form circuits enabling long-distance communication and signal integration within the body. While other organ systems are developing, projections of differentiating neurons find paths to distant targets. Subsequent post-developmental neuronal damage is catastrophic because the cues for reinnervation are no longer active. Advances in biomaterials are enabling fabrication of micro-environments that encourage neuronal regrowth and restoration of function by recreating these developmental cues. This mini-review considers new materials that employ topographical, chemical, electrical, and/or mechanical cues for use in neuronal repair. Manipulating and integrating these elements in different combinations will generate new technologies to enhance neural repair.

Daily Electrical Muscle Stimulation Enhances Functional Recovery Following Nerve Transection and Repair in Rats.

PubMed

Willand, Michael P; Chiang, Cameron D; Zhang, Jennifer J; Kemp, Stephen W P; Borschel, Gregory H; Gordon, Tessa

2015-08-01

Incomplete recovery following surgical reconstruction of damaged peripheral nerves is common. Electrical muscle stimulation (EMS) to improve functional outcomes has not been effective in previous studies. To evaluate the efficacy of a new, clinically translatable EMS paradigm over a 3-month period following nerve transection and immediate repair. Rats were divided into 6 groups based on treatment (EMS or no treatment) and duration (1, 2, or 3 months). A tibial nerve transection injury was immediately repaired with 2 epineurial sutures. The right gastrocnemius muscle in all rats was implanted with intramuscular electrodes. In the EMS group, the muscle was electrically stimulated with 600 contractions per day, 5 days a week. Terminal measurements were made after 1, 2, or 3 months. Rats in the 3-month group were assessed weekly using skilled and overground locomotion tests. Neuromuscular junction reinnervation patterns were also examined. Muscles that received daily EMS had significantly greater numbers of reinnervated motor units with smaller average motor unit sizes. The majority of muscle endplates were reinnervated by a single axon arising from a nerve trunk with significantly fewer numbers of terminal sprouts in the EMS group, the numbers being small. Muscle mass and force were unchanged but EMS improved behavioral outcomes. Our results demonstrated that EMS using a moderate stimulation paradigm immediately following nerve transection and repair enhances electrophysiological and behavioral recovery. © The Author(s) 2014.

BDNF is required for taste axon regeneration following unilateral chorda tympani nerve section.

PubMed

Meng, Lingbin; Huang, Tao; Sun, Chengsan; Hill, David L; Krimm, Robin

2017-07-01

Taste nerves readily regenerate to reinnervate denervated taste buds; however, factors required for regeneration have not yet been identified. When the chorda tympani nerve is sectioned, expression of brain-derived neurotrophic factor (BDNF) remains high in the geniculate ganglion and lingual epithelium, despite the loss of taste buds. These observations suggest that BDNF is present in the taste system after nerve section and may support taste nerve regeneration. To test this hypothesis, we inducibly deleted Bdnf during adulthood in mice. Shortly after Bdnf gene recombination, the chorda tympani nerve was unilaterally sectioned causing a loss of both taste buds and neurons, irrespective of BDNF levels. Eight weeks after nerve section, however, regeneration was differentially affected by Bdnf deletion. In control mice, there was regeneration of the chorda tympani nerve and taste buds reappeared with innervation. In contrast, few taste buds were reinnervated in mice lacking normal Bdnf expression such that taste bud number remained low. In all genotypes, taste buds that were reinnervated were normal-sized, but non-innervated taste buds remained small and atrophic. On the side of the tongue contralateral to the nerve section, taste buds for some genotypes became larger and all taste buds remained innervated. Our findings suggest that BDNF is required for nerve regeneration following gustatory nerve section. Copyright © 2017 Elsevier Inc. All rights reserved.

Ansa to recurrent laryngeal neurorrhaphy in the setting of laryngeal nerve sacrifice: a cadaveric study to evaluate a reconstructive option.

PubMed

Scharpf, Joseph; Haffey, Timothy; Rajasekaran, Karthik; Lorenz, Robert; McBride, Jennifer

2015-01-01

In certain cases, the recurrent laryngeal nerve (RLN) has to be sacrificed. This often results in an inadequate length of residual RLN to be used in a reinnervation procedure. We investigated the length of the distal stump of the RLN from the inferior border of the inferior pharyngeal constrictor muscle (IPCM), where it is frequently compromised, to its entrance into the larynx. Our objective was to determine whether this residual nerve stock was sufficient for margin clearance and neurorrhaphy. Cadaveric study Recurrent laryngeal nerves were identified in fresh frozen cadavers. The IPCM was divided, revealing the distal stump of the RLN, which was measured. Dissection was performed in 20 cadavers (40 nerves). The average length of the right RLN and the left RLN from the IPCM until it entered the larynx was 15mm and 14mm, respectively. All residual RLN remnants were of sufficient length for neurorrhaphy. Concomitant RLN reinnervation procedures in the setting of nerve sacrifice are not well described. A barrier to reinnervation in this setting may be insufficient residual nerve length for a neurorrhaphy. Often, when the RLN is sacrificed intraoperatively either iatrogenically or due to tumor invasion, it is close to the cricoarytenoid joint, at the inferior border of the IPCM. This study demonstrates that by splitting the IPCM, sufficient length can be obtained for neurorrhaphy. Copyright © 2015 Elsevier Inc. All rights reserved.

[Target volume margins for lung cancer: internal target volume/clinical target volume].

PubMed

Jouin, A; Pourel, N

2013-10-01

The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

Long-term follow-up of treatment of erectile dysfunction after radical prostatectomy using nerve grafts and end-to-side somatic-autonomic neurorraphy: a new technique.

PubMed

Souza Trindade, José Carlos; Viterbo, Fausto; Petean Trindade, André; Fávaro, Wagner José; Trindade-Filho, José Carlos Souza

2017-06-01

To study a novel penile reinnervation technique using four sural nerve grafts and end-to-side neurorraphies connecting bilaterally the femoral nerve and the cavernous corpus and the femoral nerve and the dorsal penile nerves. Ten patients (mean [± sd; range] age 60.3 [± 4.8; 54-68] years), who had undergone radical prostatectomy (RP) at least 2 years previously, underwent penile reinnervation in the present study. Four patients had undergone radiotherapy after RP. All patients reported satisfactory sexual activity prior to RP. The surgery involved bridging of the femoral nerve to the dorsal nerve of the penis and the inner part of the corpus cavernosum with sural nerve grafts and end-to-side neurorraphies. Patients were evaluated using the International Index of Erectile Function (IIEF) questionnaire and pharmaco-penile Doppler ultrasonography (PPDU) preoperatively and at 6, 12 and 18 months postoperatively, and using a Clinical Evolution of Erectile Function (CEEF) questionnaire, administered after 36 months. The IIEF scores showed improvements with regard to erectile dysfunction (ED), satisfaction with intercourse and general satisfaction. Evaluation of PPDU velocities did not reveal any difference between the right and left sides or among the different time points. The introduction of nerve grafts neither caused fibrosis of the corpus cavernosum, nor reduced penile vascular flow. CEEF results showed that sexual intercourse began after a mean of 13.7 months with frequency of sexual intercourse varying from once daily to once monthly. Acute complications were minimal. The study was limited by the small number of cases. A total of 60% of patients were able to achieve full penetration, on average, 13 months after reinnervation surgery. Patients previously submitted to radiotherapy had slower return of erectile function. We conclude that penile reinnervation surgery is a viable technique, with effective results, and could offer a new treatment method for ED after

Characterization of disability following traumatic through knee and transfemoral amputations.

PubMed

Tennent, David J; Polfer, Elizabeth M; Sgromolo, Nicole M; Krueger, Chad A; Potter, Benjamin K

2018-06-01

The purpose of this study is to characterize through knee and transfemoral amputations following severe traumatic injuries. A retrospective review of all transfemoral and through knee amputations sustained by United States military service members from 1 October 2001 to 30 July 2011 was conducted. Data from the Department of Defense Trauma Registry, the Armed Forces Health Longitudinal Technology Application, inpatient medical records and the Physical Evaluation Board Liaison Offices were queried in order to obtain characteristics related to injury sustained, demographics, treatment, and disability/mental health outcome data. A total of 1631 amputations in 1315 patients were identified. Of these there were 37 through knee and 296 were transfemoral amputations. Adequate records for detailed analysis were available on 140 and 25 transfemoral and through knee amputations respectively. There were no significant differences in demographic information, injury mechanism, initial injury severity score, or associated injuries, to include contralateral amputations. There was no significant difference in average disability rating (67.9% vs 78.3%, p = 0.46) or number of service members determined to be fully disabled (42.2% vs 28.6% p = 0.33) between the transfemoral and through knee amputation groups. Whereas there was no difference between groups preoperatively, the knee disarticulation group displayed a higher rate of mental health diagnoses post-amputation (96% vs 72%, p < 0.001) and a higher preponderance of anxiety related disorders than the transfemoral amputees (26.92% vs 12.96%, p = 0.0129). Among this military amputee through knee and transfemoral amputees displayed similar physical disability profiles. However, the through knee amputees displayed a higher level of anxiety related disorders and mental health diagnosis overall. While we don't believe this relationship to be causal in nature, this finding reflects the importance of paying particular

Referral of sensation to an advanced humanoid robotic hand prosthesis.

PubMed

Rosén, Birgitta; Ehrsson, H Henrik; Antfolk, Christian; Cipriani, Christian; Sebelius, Fredrik; Lundborg, Göran

2009-01-01

Hand prostheses that are currently available on the market are used by amputees to only a limited extent, partly because of lack of sensory feedback from the artificial hand. We report a pilot study that showed how amputees can experience a robot-like advanced hand prosthesis as part of their own body. We induced a perceptual illusion by which touch applied to the stump of the arm was experienced from the artificial hand. This illusion was elicited by applying synchronous tactile stimulation to the hidden amputation stump and the robotic hand prosthesis in full view. In five people who had had upper limb amputations this stimulation caused referral touch sensation from the stump to the artificial hand, and the prosthesis was experienced more like a real hand. We also showed that this illusion can work when the amputee controls the movements of the artificial hand by recordings of the arm muscle activity with electromyograms. These observations indicate that the previously described "rubber hand illusion" is also valid for an advanced hand prosthesis, even when it has a robotic-like appearance.

Limb Position Tolerant Pattern Recognition for Myoelectric Prosthesis Control with Adaptive Sparse Representations From Extreme Learning.

PubMed

Betthauser, Joseph L; Hunt, Christopher L; Osborn, Luke E; Masters, Matthew R; Levay, Gyorgy; Kaliki, Rahul R; Thakor, Nitish V

2018-04-01

Myoelectric signals can be used to predict the intended movements of an amputee for prosthesis control. However, untrained effects like limb position changes influence myoelectric signal characteristics, hindering the ability of pattern recognition algorithms to discriminate among motion classes. Despite frequent and long training sessions, these deleterious conditional influences may result in poor performance and device abandonment. We present a robust sparsity-based adaptive classification method that is significantly less sensitive to signal deviations resulting from untrained conditions. We compare this approach in the offline and online contexts of untrained upper-limb positions for amputee and able-bodied subjects to demonstrate its robustness compared against other myoelectric classification methods. We report significant performance improvements () in untrained limb positions across all subject groups. The robustness of our suggested approach helps to ensure better untrained condition performance from fewer training conditions. This method of prosthesis control has the potential to deliver real-world clinical benefits to amputees: better condition-tolerant performance, reduced training burden in terms of frequency and duration, and increased adoption of myoelectric prostheses.

Quantifying prosthetic gait deviation using simple outcome measures

PubMed Central

Kark, Lauren; Odell, Ross; McIntosh, Andrew S; Simmons, Anne

2016-01-01

AIM: To develop a subset of simple outcome measures to quantify prosthetic gait deviation without needing three-dimensional gait analysis (3DGA). METHODS: Eight unilateral, transfemoral amputees and 12 unilateral, transtibial amputees were recruited. Twenty-eight able-bodied controls were recruited. All participants underwent 3DGA, the timed-up-and-go test and the six-minute walk test (6MWT). The lower-limb amputees also completed the Prosthesis Evaluation Questionnaire. Results from 3DGA were summarised using the gait deviation index (GDI), which was subsequently regressed, using stepwise regression, against the other measures. RESULTS: Step-length (SL), self-selected walking speed (SSWS) and the distance walked during the 6MWT (6MWD) were significantly correlated with GDI. The 6MWD was the strongest, single predictor of the GDI, followed by SL and SSWS. The predictive ability of the regression equations were improved following inclusion of self-report data related to mobility and prosthetic utility. CONCLUSION: This study offers a practicable alternative to quantifying kinematic deviation without the need to conduct complete 3DGA. PMID:27335814

Developing Non-Somatotopic Phantom Finger Sensation to Comparable Levels of Somatotopic Sensation through User Training With Electrotactile Stimulation.

PubMed

Chai, Guohong; Zhang, Dingguo; Zhu, Xiangyang

2017-05-01

Cutaneous electrical stimulation can provide tactile feedback for upper-limb amputees through somatotopic feedback (SF) or non-somatotopic feedback (NF). The SF delivers electrotactile stimulus to projection finger maps (PFMs) on the stumps of amputees, which outperforms NF that transfers stimulus to other human intact skin areas in general. However, the SF areas on stumps are very limited and often occupied by electromyography (EMG) sensors in application of myoelectric prosthesis. This work aims at improving NF performance on human upper arms through user training with electrotactile stimulation. The experiments were conducted over seven consecutive days on nine able-bodied subjects and two forearm amputees. The performance measures of NF/SF included the correct identification rates (CIR s ), the response time and the NASA-TLX questionnaire. The between-day CIR s on NF sites increased logarithmically with a mean course of 3-day rapid-improving phase and plateaued in the relative-steady phase. The response time and NASA-TLX scores could also rapidly reduce to the comparable levels of the SF areas during the same mean period of 3-day rapid-improving phase, respectively. These results indicated that the performance of NF could be highly improved to the equivalent level as that of SF through 3-day electrotactile training, which we named as "3-day effect". It provides important insights that intact skin areas without phantom sensations can effectively replace SF sites to transfer tactile feedback after continuous user training, which validates effectiveness of non-invasive interfaces of tactile feedback for upper-limb amputees in practice.

Functional Assessment of the Vanderbilt Multigrasp Myoelectric Hand: A Continuing Case Study

PubMed Central

Dalley, Skyler A.; Bennett, Daniel A.; Goldfarb, Michael

2015-01-01

This paper presents a case study involving the functional assessment of the Vanderbilt Multigrasp (VMG) hand prosthesis on a single transradial amputee subject. In particular, a transradial amputee subject performed the Southampton Hand Assessment Procedure (SHAP) using the hand prosthesis and multigrasp myoelectric controller in a series of experimental sessions occurring over a multi-week time span. The subject’s index of function (IoF) improved with each session, although essentially plateaued after the fourth session, resulting in a IoF score of 87, which compares favorably to SHAP scores published in previous studies. PMID:25571412

Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

PubMed Central

2015-01-01

There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

Neurotrophin expression and laryngeal muscle pathophysiology following recurrent laryngeal nerve transection

PubMed Central

WANG, BAOXIN; YUAN, JUNJIE; XU, JIAFENG; XIE, JIN; WANG, GUOLIANG; DONG, PIN

2016-01-01

Laryngeal palsy often occurs as a result of recurrent laryngeal or vagal nerve injury during oncological surgery of the head and neck, affecting quality of life and increasing economic burden. Reinnervation following recurrent laryngeal nerve (RLN) injury is difficult despite development of techniques, such as neural anastomosis, nerve grafting and creation of a laryngeal muscle pedicle. In the present study, due to the limited availability of human nerve tissue for research, a rat model was used to investigate neurotrophin expression and laryngeal muscle pathophysiology in RLN injury. Twenty-five male Sprague-Dawley rats underwent right RLN transection with the excision of a 5-mm segment. Vocal fold movements, vocalization, histology and immunostaining were evaluated at different time-points (3, 6, 10 and 16 weeks). Although vocalization was restored, movement of the vocal fold failed to return to normal levels following RLN injury. The expression of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor differed in the thyroarytenoid (TA) and posterior cricoarytenoid muscles. The number of axons did not increase to baseline levels over time. Furthermore, normal muscle function was unlikely with spontaneous reinnervation. During regeneration following RLN injury, differences in the expression levels of neurotrophic factors may have resulted in preferential reinnervation of the TA muscles. Data from the present study indicated that neurotrophic factors may be applied for restoring the function of the laryngeal nerve following recurrent injury. PMID:26677138

Neurotrophin expression and laryngeal muscle pathophysiology following recurrent laryngeal nerve transection.

PubMed

Wang, Baoxin; Yuan, Junjie; Xu, Jiafeng; Xie, Jin; Wang, Guoliang; Dong, Pin

2016-02-01

Laryngeal palsy often occurs as a result of recurrent laryngeal or vagal nerve injury during oncological surgery of the head and neck, affecting quality of life and increasing economic burden. Reinnervation following recurrent laryngeal nerve (RLN) injury is difficult despite development of techniques, such as neural anastomosis, nerve grafting and creation of a laryngeal muscle pedicle. In the present study, due to the limited availability of human nerve tissue for research, a rat model was used to investigate neurotrophin expression and laryngeal muscle pathophysiology in RLN injury. Twenty-five male Sprague-Dawley rats underwent right RLN transection with the excision of a 5-mm segment. Vocal fold movements, vocalization, histology and immunostaining were evaluated at different time-points (3, 6, 10 and 16 weeks). Although vocalization was restored, movement of the vocal fold failed to return to normal levels following RLN injury. The expression of brain‑derived neurotrophic factor and glial cell line-derived neurotrophic factor differed in the thyroarytenoid (TA) and posterior cricoarytenoid muscles. The number of axons did not increase to baseline levels over time. Furthermore, normal muscle function was unlikely with spontaneous reinnervation. During regeneration following RLN injury, differences in the expression levels of neurotrophic factors may have resulted in preferential reinnervation of the TA muscles. Data from the present study indicated that neurotrophic factors may be applied for restoring the function of the laryngeal nerve following recurrent injury.

The anabolic steroid nandrolone enhances motor and sensory functional recovery in rat median nerve repair with long interpositional nerve grafts.

PubMed

Ghizoni, Marcos Flávio; Bertelli, Jayme Augusto; Grala, Carolina Giesel; da Silva, Rosemeri Maurici

2013-01-01

Recovery from peripheral nerve repair is frequently incomplete. Hence drugs that enhance nerve regeneration are needed clinically. To study the effects of nandrolone decanoate in a model of deficient reinnervation in the rat. In 40 rats, a 40-mm segment of the left median nerve was removed and interposed between the stumps of a sectioned right median nerve. Starting 7 days after nerve grafting and continuing over a 6-month period, we administered nandrolone at a dose of 5 mg/kg/wk to half the rats (n = 20). All rats were assessed behaviorally for grasp function and nociceptive recovery for up to 6 months. At final assessment, reinnervated muscles were tested electrophysiologically and weighed. Results were compared between rats that had received versus not received nandrolone and versus 20 nongrafted controls. Rats in the nandrolone group recovered finger flexion faster. At 90 days postsurgery, they had recovered 42% of normal grasp strength versus just 11% in rats grafted but not treated with nandrolone. At 180 days, the average values for grasp strength recovery in the nandrolone and no-nandrolone groups were 40% and 33% of normal values for controls, respectively. At 180 days, finger flexor muscle twitch strength was 16% higher in treated versus nontreated rats. Thresholds for nociception were not detected in either group 90 days after nerve grafting. At 180 days, nociceptive thresholds were significantly lower in the nandrolone group. Nandrolone decanoate improved functional recovery in a model of deficient reinnervation.

Muscle fiber types composition and type identified endplate morphology of forepaw intrinsic muscles in the rat.

PubMed

Pan, Feng; Mi, Jing-Yi; Zhang, Yan; Pan, Xiao-Yun; Rui, Yong-Jun

2016-06-01

The failure to accept reinnervation is considered to be one of the reasons for the poor motor functional recovery of intrinsic hand muscles (IHMs) after nerve injury. Rat could be a suitable model to be used in simulating motor function recovery of the IHMs after nerve injury as to the similarities in function and anatomy of the muscles between human and rat. However, few studies have reported the muscle fiber types composition and endplate morphologic characteristics of intrinsic forepaw muscles (IFMs) in the rat. In this study, the myosin heavy chain isoforms and acetylcholine receptors were stained by immunofluorescence to show the muscle fiber types composition and endplates on type-identified fibers of the lumbrical muscles (LMs), interosseus muscles (IMs), abductor digiti minimi (AM) and flexor pollicis brevis (FM) in rat forepaw. The majority of IFMs fibers were labeled positively for fast-switch fiber. However, the IMs were composed of only slow-switch fiber. With the exception of the IMs, the other IFMs had a part of hybrid fibers. Two-dimensional morphological characteristics of endplates on I and IIa muscle fiber had no significant differences among the IFMs. The LMs is the most suitable IFMs of rat to stimulate reinnervation of the IHMs after nerve injury. Gaining greater insight into the muscle fiber types composition and endplate morphology in the IFMs of rat may help understand the pathological and functional changes of IFMs in rat model stimulating reinnervation of IHMs after peripheral nerve injury.

Fall Detection in Individuals With Lower Limb Amputations Using Mobile Phones: Machine Learning Enhances Robustness for Real-World Applications.

PubMed

Shawen, Nicholas; Lonini, Luca; Mummidisetty, Chaithanya Krishna; Shparii, Ilona; Albert, Mark V; Kording, Konrad; Jayaraman, Arun

2017-10-11

Automatically detecting falls with mobile phones provides an opportunity for rapid response to injuries and better knowledge of what precipitated the fall and its consequences. This is beneficial for populations that are prone to falling, such as people with lower limb amputations. Prior studies have focused on fall detection in able-bodied individuals using data from a laboratory setting. Such approaches may provide a limited ability to detect falls in amputees and in real-world scenarios. The aim was to develop a classifier that uses data from able-bodied individuals to detect falls in individuals with a lower limb amputation, while they freely carry the mobile phone in different locations and during free-living. We obtained 861 simulated indoor and outdoor falls from 10 young control (non-amputee) individuals and 6 individuals with a lower limb amputation. In addition, we recorded a broad database of activities of daily living, including data from three participants' free-living routines. Sensor readings (accelerometer and gyroscope) from a mobile phone were recorded as participants freely carried it in three common locations-on the waist, in a pocket, and in the hand. A set of 40 features were computed from the sensors data and four classifiers were trained and combined through stacking to detect falls. We compared the performance of two population-specific models, trained and tested on either able-bodied or amputee participants, with that of a model trained on able-bodied participants and tested on amputees. A simple threshold-based classifier was used to benchmark our machine-learning classifier. The accuracy of fall detection in amputees for a model trained on control individuals (sensitivity: mean 0.989, 1.96*standard error of the mean [SEM] 0.017; specificity: mean 0.968, SEM 0.025) was not statistically different (P=.69) from that of a model trained on the amputee population (sensitivity: mean 0.984, SEM 0.016; specificity: mean 0.965, SEM 0

Association between amputation, arthritis and osteopenia in British male war veterans with major lower limb amputations.

PubMed

Kulkarni, J; Adams, J; Thomas, E; Silman, A

1998-08-01

To investigate the association between amputation, osteoarthritis and osteopenia in male war veterans with major lower limb amputations. Specific questions were to determine whether lower limb amputees following trauma are at subsequent risk of developing osteoarthritis (OA) and osteoporosis of the hip on both the amputated and nonamputated sides. Retrospective cohort study in British Male Second World War veterans with major unilateral lower limb amputations. Seventy-five male Second World War veterans with major lower limb amputations known to be alive were invited to participate from a subregional rehabilitation centre. After exclusions, 44 agreed to attend for examination and radiological screening. The presence of hip OA was determined from a single anterior posterior pelvic X-ray using two approaches: minimum joint space and the Kellgren and Lawrence (K&L) scoring system. Bone mineral density (BMD) was measured by a dual energy X-ray absorptiometry (DXA) scan and prosthetic rehabilitation outcome measures were recorded. Twenty-seven (61%) hips on the amputated side and 10 (23%) on the nonamputated side were positive for OA (based on Kellgren and Lawrence grade of >2). Using a minimum joint space threshold of below 2.5 mm, 24 (55%) hips on the amputation side and 8 (18%) on the nonamputated side were also positive for OA. There was a threefold increased risk of OA for those with above-knee compared to a below-knee amputation. By contrast, from published general population surveys only 4 (11%) cases of hip OA would have been expected on both the amputated and nonamputated hips. There was a significant decrease in femoral neck BMD in the amputated side (p <0.0001) and significantly lower BMD in above-knee amputees than in below-knee amputees (p = 0.0027) as compared to normal age- and sex-matched population. Male war veterans with unilateral major lower limb amputations develop significantly more osteoarthritis of the hip than expected on both ipsi- and

Determination of the effects of playing soccer on physical fitness in individuals with transtibial amputation.

PubMed

Guchan, Zehra; Bayramlar, Kezban; Ergun, Nevin

2017-06-01

The aim of this paper is to determine the effects of playing soccer on various components of physical performance such as body composition, muscular endurance, anaerobic power, flexibility, balance, and speed of individuals with transtibial amputation. Twelve amputee football players aged 26.67±7.76 years and twelve sedentary individuals aged 33±6.7 years were involved in this study. Body composition, and isotonic and isometric endurance of trunk muscles were assessed. Vertical jump test, sit-and-reach test, modified Thomas test, Berg Balance Scale, L test, and figure-of-eight walk (F8W) test were used to assess other physical fitness parameters. The Body Mass Index, waist circumference and body fat percentages of the amputee soccer players were significantly lower than the sedentary amputees (P<0.05). The endurance of back extensors was significantly higher in the soccer group (119.33±47.15 s) than the endurance in the control group (26.25±15.96 s) (P<0.001). Subjects belonging to the soccer group had significantly higher anaerobic power than those in the control group (P<0.05). Flexibility, as assessed by the sit-and-reach test was significantly higher for the soccer group (P=0.002), whereas the modified Thomas test, which is also used to measure flexibility, indicated no significant difference among both groups (P>0.05). Balance was higher in the soccer group (P=0.023). The completion period of the F8W test was significantly lower in the soccer group (4.54±0.9 s) than in the control group (7.71±2.25 s) (P<0.001). No significant difference was observed in the numbers of steps measured during the F8W test (P=0.231). This is the first study which investigates the effects of sports on the physical fitness of individuals with transtibial amputation with the inclusion of a control group. Overall findings present the benefits of participating in playing soccer on physical fitness parameters of amputees, but further studies with randomized controlled trials, with

Use of and confidence in administering outcome measures among clinical prosthetists: Results from a national survey and mixed-methods training program.

PubMed

Gaunaurd, Ignacio; Spaulding, Susan E; Amtmann, Dagmar; Salem, Rana; Gailey, Robert; Morgan, Sara J; Hafner, Brian J

2015-08-01

Outcome measures can be used in prosthetic practices to evaluate interventions, inform decision making, monitor progress, document outcomes, and justify services. Strategies to enhance prosthetists' ability to use outcome measures are needed to facilitate their adoption in routine practice. To assess prosthetists' use of outcome measures and evaluate the effects of training on their confidence in administering performance-based measures. Cross-sectional and single-group pretest-posttest survey. Seventy-nine certified prosthetists (mean of 16.0 years of clinical experience) were surveyed about their experiences with 20 standardized outcome measures. Prosthetists were formally trained by the investigators to administer the Timed Up and Go and Amputee Mobility Predictor. Prosthetists' confidence in administering the Timed Up and Go and Amputee Mobility Predictor was measured before and after training. The majority of prosthetists (62%) were classified as non-routine outcome measure users. Confidence administering the Timed Up and Go and Amputee Mobility Predictor prior to training was low-to-moderate across the study sample. Training significantly (p < 0.0001) improved prosthetists' confidence in administering both instruments. Prosthetists in this study reported limited use of and confidence with standardized outcome measures. Interactive training resulted in a statistically significant increase of prosthetists' confidence in administering the Timed Up and Go and Amputee Mobility Predictor and may facilitate use of outcome measures in clinical practice. Frequency of outcome measure use in the care of persons with limb loss has not been studied. Study results suggest that prosthetists may not regularly use standardized outcome measures and report limited confidence in administering them. Training enhances confidence and may encourage use of outcome measures in clinical practice. © The International Society for Prosthetics and Orthotics 2014.

Design of ligand-targeted nanoparticles for enhanced cancer targeting

NASA Astrophysics Data System (ADS)

Stefanick, Jared F.

Ligand-targeted nanoparticles are increasingly used as drug delivery vehicles for cancer therapy, yet have not consistently produced successful clinical outcomes. Although these inconsistencies may arise from differences in disease models and target receptors, nanoparticle design parameters can significantly influence therapeutic efficacy. By employing a multifaceted synthetic strategy to prepare peptide-targeted nanoparticles with high purity, reproducibility, and precisely controlled stoichiometry of functionalities, this work evaluates the roles of polyethylene glycol (PEG) coating, ethylene glycol (EG) peptide-linker length, peptide hydrophilicity, peptide density, and nanoparticle size on tumor targeting in a systematic manner. These parameters were analyzed in multiple disease models by targeting human epidermal growth factor receptor 2 (HER2) in breast cancer and very late antigen-4 (VLA-4) in multiple myeloma to demonstrate the widespread applicability of this approach. By increasing the hydrophilicity of the targeting peptide sequence and simultaneously optimizing the EG peptide-linker length, the in vitro cellular uptake of targeted liposomes was significantly enhanced. Specifically, including a short oligolysine chain adjacent to the targeting peptide sequence effectively increased cellular uptake ~80-fold using an EG6 peptide-linker compared to ~10-fold using an EG45 linker. In vivo, targeted liposomes prepared in a traditional manner lacking the oligolysine chain demonstrated similar biodistribution and tumor uptake to non-targeted liposomes. However, by including the oligolysine chain, targeted liposomes using an EG45 linker significantly improved tumor uptake ~8-fold over non-targeted liposomes, while the use of an EG6 linker decreased tumor accumulation and uptake, owing to differences in cellular uptake kinetics, clearance mechanisms, and binding site barrier effects. To further improve tumor targeting and enhance the selectivity of targeted

Innovations in prosthetic interfaces for the upper extremity.

PubMed

Kung, Theodore A; Bueno, Reuben A; Alkhalefah, Ghadah K; Langhals, Nicholas B; Urbanchek, Melanie G; Cederna, Paul S

2013-12-01

Advancements in modern robotic technology have led to the development of highly sophisticated upper extremity prosthetic limbs. High-fidelity volitional control of these devices is dependent on the critical interface between the patient and the mechanical prosthesis. Recent innovations in prosthetic interfaces have focused on several control strategies. Targeted muscle reinnervation is currently the most immediately applicable prosthetic control strategy and is particularly indicated in proximal upper extremity amputations. Investigation into various brain interfaces has allowed acquisition of neuroelectric signals directly or indirectly from the central nervous system for prosthetic control. Peripheral nerve interfaces permit signal transduction from both motor and sensory nerves with a higher degree of selectivity. This article reviews the current developments in each of these interface systems and discusses the potential of these approaches to facilitate motor control and sensory feedback in upper extremity neuroprosthetic devices.

SuperTarget goes quantitative: update on drug–target interactions

PubMed Central

Hecker, Nikolai; Ahmed, Jessica; von Eichborn, Joachim; Dunkel, Mathias; Macha, Karel; Eckert, Andreas; Gilson, Michael K.; Bourne, Philip E.; Preissner, Robert

2012-01-01

There are at least two good reasons for the on-going interest in drug–target interactions: first, drug-effects can only be fully understood by considering a complex network of interactions to multiple targets (so-called off-target effects) including metabolic and signaling pathways; second, it is crucial to consider drug-target-pathway relations for the identification of novel targets for drug development. To address this on-going need, we have developed a web-based data warehouse named SuperTarget, which integrates drug-related information associated with medical indications, adverse drug effects, drug metabolism, pathways and Gene Ontology (GO) terms for target proteins. At present, the updated database contains >6000 target proteins, which are annotated with >330 000 relations to 196 000 compounds (including approved drugs); the vast majority of interactions include binding affinities and pointers to the respective literature sources. The user interface provides tools for drug screening and target similarity inclusion. A query interface enables the user to pose complex queries, for example, to find drugs that target a certain pathway, interacting drugs that are metabolized by the same cytochrome P450 or drugs that target proteins within a certain affinity range. SuperTarget is available at http://bioinformatics.charite.de/supertarget. PMID:22067455

Development and preliminary evaluation of a new anatomically based prosthetic alignment method for below-knee prosthesis.

PubMed

Tafti, Nahid; Karimlou, Masoud; Mardani, Mohammad Ali; Jafarpisheh, Amir Salar; Aminian, Gholam Reza; Safari, Reza

2018-04-20

The objectives of current study were to a) assess similarities and relationships between anatomical landmark-based angles and distances of lower limbs in unilateral transtibial amputees and b) develop and evaluate a new anatomically based static prosthetic alignment method. First sub-study assessed the anthropometrical differences and relationships between the lower limbs in the photographs taken from amputees. Data were analysed via paired t-test and regression analysis. Results show no significant differences in frontal and transverse planes. In the sagittal plane, the anthropometric parameters of the amputated limb were significantly correlated to the corresponding variables of the sound limb. The results served as bases for the development of a new prosthetic alignment method. The method was evaluated on a single subject study. Prosthetic alignment carried out by an experienced prosthetist was compared with such alignment adjusted by an inexperienced prosthetist but with the use of the developed method. In sagittal and frontal planes, the socket angle was tuned with respect to the shin angle, and the position of the prosthetic foot was tuned in relation to the pelvic landmarks. Further study is needed to assess the proposed method on a larger sample of amputees and prosthetists.

Investigation of the syndrome of apotemnophilia and course of a cognitive-behavioural therapy.

PubMed

Braam, Arjan W; Visser, Sako; Cath, Daniëlle C; Hoogendijk, W J G

2006-01-01

The syndrome of apotemnophilia, body integrity or amputee identity disorder, is defined as the desire for amputation of a healthy limb, and may be accompanied by behaviour of pretending to be an amputee and sometimes, but not necessarily, by sexual arousal. A case history is presented of a 35-year-old man who was referred because of his desire for amputation of his left leg, without sexual connotations. The course of a combined cognitive behavioural psychotherapy with SSRI treatment is described. Symptoms showed considerable similarity with obsessive-compulsive disorder, and some similarity with body dysmorphic disorder according to DSM-IV, but the core symptom seemed to be strongly connected with a sense of identity. Treatment with a selective serotonin re-uptake inhibitor decreased levels of distress only. The effects of cognitive restructuring of the psychotherapy were limited, whereas the behavioural elements substantially reduced the behaviour of pretending to be an amputee. The rare syndrome of apotemnophilia raises unresolved questions of classification. Psychotic disorders should be ruled out carefully. The model designed in the current cognitive behavioural approach may serve as a starting point for further development of intervention protocols for this rare disorder.

[Treatment of bilateral vocal cord paralysis by hemi-phrenic nerve transfer].

PubMed

Song, W; Li, M; Zheng, H L; Sun, L; Chen, S C; Chen, D H; Liu, F; Zhu, M H; Zhang, C Y; Wang, W

2017-04-07

Objective: To investigate the surgical effect of reinnervation of bilateral posterior cricoarytenoid muscles(PCA) with left hemi-phrenic nerve and endoscopic laser arytenoid resection in bilateral vocal cord fold paralysis(BVFP) and to analyze the pros and cons of the two methods. Methods: One hundred and seventeen BVFP patients who underwent reinnervation of bilateral PCA using the left hemi-phrenic nerve approach (nerve group, n =52) or laser arytenoidectomy(laser group, n =65) were enrolled in this study from Jan.2009 to Dec.2015.Vocal perception evaluation, video stroboscopy, pulmonary function test and laryngeal electromyography were preformed in all patients both preoperatively and postoperative1y.Extubution rate was calculated postoperative1y. Results: Most of the vocal function parameters in nerve group were improved postoperatively compared with preoperative parameters, albeit without a significant difference( P >0.05), while laser group showed a significant deterioration in voice quality postoperative1y( P <0.05). The two groups showed significant difference in voice quality postoperative1y( P <0.05). Videostroboscopy showed that vocal fold on the operated side in both groups could abduct to various extent postoperatively, which showed significant difference when compared with preoperative abductive movements ( P <0.05). But the amplitude in nerve group was larger than that in laser group ( P <0.05). 89% of the patients in nerve group were inhale physiological vocal cord abductions. Postoperative glottal closure showed no significant difference in nerve group ( P >0.05), while showed various increment in laser group( P <0.05). Differences between the two groups were statistically significant( P <0.05). The pulmonary function in both groups was better after operation, reaching the reference value. Postoperative laryngeal electromyography confirmed successful reinnervation of the bilateral PCA muscles. The decannulation rate were 88.5% and 81.5% in nerve

Use it or Lose It: Tonic Activity of Slow Motoneurons Promotes Their Survival and Preferentially Increases Slow Fiber-Type Groupings in Muscles of Old Lifelong Recreational Sportsmen

PubMed Central

Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Zampieri, Sandra

2016-01-01

Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active

Use it or Lose It: Tonic Activity of Slow Motoneurons Promotes Their Survival and Preferentially Increases Slow Fiber-Type Groupings in Muscles of Old Lifelong Recreational Sportsmen.

PubMed

Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Zampieri, Sandra

2016-09-15

Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active

Attentional Control via Parallel Target-Templates in Dual-Target Search

PubMed Central

Barrett, Doug J. K.; Zobay, Oliver

2014-01-01

Simultaneous search for two targets has been shown to be slower and less accurate than independent searches for the same two targets. Recent research suggests this ‘dual-target cost’ may be attributable to a limit in the number of target-templates than can guide search at any one time. The current study investigated this possibility by comparing behavioural responses during single- and dual-target searches for targets defined by their orientation. The results revealed an increase in reaction times for dual- compared to single-target searches that was largely independent of the number of items in the display. Response accuracy also decreased on dual- compared to single-target searches: dual-target accuracy was higher than predicted by a model restricting search guidance to a single target-template and lower than predicted by a model simulating two independent single-target searches. These results are consistent with a parallel model of dual-target search in which attentional control is exerted by more than one target-template at a time. The requirement to maintain two target-templates simultaneously, however, appears to impose a reduction in the specificity of the memory representation that guides search for each target. PMID:24489793

[The path to customized prosthesis: role of the occupational therapist in the recovery of autonomy].

PubMed

Fogliaresi, Stefania; Mulè, Chiara; Borboni, Alberto; Taveggia, Giovanni

2015-01-01

The aim of the rehabilitative treatment of the amputee is to facilitate the reintegration of the patient into daily life: within social, family, and working contexts. Occupational therapy relates to 'doing', to everyday life. These are the activities carried out by individuals during daily life: catching the bus, driving a car, cooking a meal, playing cards or changing a light bulb. During the process of rehabilitation of the amputee the occupational therapist must evaluate the residual capacities of the patient, discover their needs and requirements so as to develop suitable rehabilitative strategiesfor retraining motor-skills, acceptance of the new living conditions, and social reintegration.

An analytical approach to test and design upper limb prosthesis.

PubMed

Veer, Karan

2015-01-01

In this work the signal acquiring technique, the analysis models and the design protocols of the prosthesis are discussed. The different methods to estimate the motion intended by the amputee from surface electromyogram (SEMG) signals based on time and frequency domain parameters are presented. The experiment proposed that the used techniques can help significantly in discriminating the amputee's motions among four independent activities using dual channel set-up. Further, based on experimental results, the design and working of an artificial arm have been covered under two constituents--the electronics design and the mechanical assembly. Finally, the developed hand prosthesis allows the amputated persons to perform daily routine activities easily.

Nerve injury affects the capillary supply in rat slow and fast muscles differently.

PubMed

Cebasek, Vita; Radochová, Barbora; Ribaric, Samo; Kubínová, Lucie; Erzen, Ida

2006-02-01

The goal of this study was to determine the acute effects of permanent denervation on the length density of the capillary network in rat slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles and the effect of short-lasting reinnervation in slow muscle only. Denervation was performed by cutting the sciatic nerve. Both muscles were excised 2 weeks later. Reinnervation was studied 4 weeks after nerve crush in SOL muscle only. Capillaries and muscle fibres were visualised by triple immunofluorescent staining with antibodies against CD31 and laminin and with fluorescein-labelled Griffonia (Bandeira) simplicifolia lectin. A recently developed stereological approach allowing the estimation of the length of capillaries adjacent to each individual fibre (Lcap/Lfib) was employed. Three-dimensional virtual test grids were applied to stacks of optical images captured with a confocal microscope and their intersections with capillaries and muscle fibres were counted. Interrelationships among capillaries and muscle fibres were demonstrated with maximum intensity projection of the acquired stacks of optical images. The course of capillaries in EDL seemed to be parallel to the fibre axes, whereas in SOL, their preferential direction deviated from the fibre axes and formed more cross-connections among neighbouring capillaries. Lcap/Lfib was clearly reduced in denervated SOL but remained unchanged in EDL, although the muscle fibres significantly atrophied in both muscle types. When soleus muscle was reinnervated, capillary length per unit fibre length was completely restored. The physiological background for the different responses of the capillary network in slow and fast muscle is discussed.

Hypoglossal-facial anastomosis (HFA) over a 10 mm gap bridged by a Y-tube-conduit enhances neurite regrowth and reduces collateral axonal branching at the lesion site.

PubMed

Ozsoy, Umut; Demirel, Bahadir Murat; Hizay, Arzu; Ozsoy, Ozlem; Ankerne, Janina; Angelova, Srebrina; Sarikcioglu, Levent; Ucar, Yasar; Angelov, Doychin N

2011-01-01

The outcome of severe peripheral nerve injuries requiring surgical repair (transection and suture) is usually poor. Recent work suggests that direct suture of nerves increases collagen production and provides unfavourable conditions for a proper axonal regrowth. We tested whether entubulation of the hypoglossal nerve into a Y-tube conduit connecting it with the zygomatic and buccal facial nerve branches would improve axonal pathfinding at the lesion site, quality of muscle reinnervation and recovery of vibrissal whisking. For hypoglossal-facial anastomosis (HFA) over a Y-tube (HFA-Y-tube) the proximal stump of the hypoglossal nerve was entubulated and sutured into the long arm of a Y-tube (isogeneic abdominal aorta with its bifurcation). The zygomatic and buccal facial branches were entubulated and sutured to the short arms of the Y-tube. Restoration of vibrissal motor performance, degree of collateral axonal branching at the lesion site and quality of neuro-muscular junction (NMJ) reinnervation were compared to animals receiving HFA-Coaptation (no entubulation) after 4 months. HFA-Y-tube reduced collateral axonal branching. However it failed to reduce the proportion of polyinnervated NMJ and did not improve functional outcome when compared to HFA-Coaptation. Elimination of compression by tightly opposed nerve fragments improved axonal pathfinding. However, biometric analysis of vibrissae movements did not show positive effects suggesting that polyneuronal reinnervation - rather than collateral branching - may be the critical limiting factor. Since polyinnervation of muscle fibers is activity-dependent and can be manipulated, the present findings raise hopes that clinically feasible and effective therapies after HFA could be soon designed and tested.

A sleeping phantom leg awakened following hemicolectomy, thrombosis, and chemotherapy: a case report.

PubMed

Giummarra, Melita J; Bradshaw, John L; Nicholls, Michael Er; Georgiou-Karistianis, Nellie; Gibson, Stephen J

2011-05-25

We describe the case of a patient who experienced phantom pain that began 42 years after right above-the-knee amputation. Immediately prior to phantom pain onset, this long-term amputee had experienced, in rapid succession, cancer, hemicolectomy, chemotherapy, and thrombotic occlusion. Very little has been published to date on the association between chemotherapy and exacerbation of neuropathic pain in amputees, let alone the phenomenon of bringing about pain in amputees who have been pain-free for many decades. While this patient presented with a unique profile following a rare sequence of medical events, his case should be recognized considering the frequent co-occurrence of osteomyelitis, chemotherapy, and amputation. A 68-year-old Australian Caucasian man presented 42 years after right above-the-knee amputation with phantom pain immediately following hemicolectomy, thrombotic occlusion in the amputated leg, and chemotherapy treatment with leucovorin and 5-fluorouracil. He exhibited probable hyperalgesia with a reduced pinprick threshold and increased stump sensitivity, indicating likely peripheral and central sensitization. Our patient, who had long-term nerve injury due to amputation, together with recent ischemic nerve and tissue injury due to thrombosis, exhibited likely chemotherapy-induced neuropathy. While he presented with unique treatment needs, cases such as this one may actually be quite common considering that osteosarcoma can frequently lead to amputation and be followed by chemotherapy. The increased susceptibility of amputees to developing potentially intractable chemotherapy-induced neuropathic pain should be taken into consideration throughout the course of chemotherapy treatment. Patients in whom chronic phantom pain then develops, perhaps together with mobility issues, inevitably place greater demands on healthcare service providers that require treatment by various clinical specialists, including oncologists, neurologists, prosthetists, and

Effect of Running Speed and Leg Prostheses on Mediolateral Foot Placement and Its Variability

PubMed Central

Arellano, Christopher J.; McDermott, William J.; Kram, Rodger; Grabowski, Alena M.

2015-01-01

This study examined the effects of speed and leg prostheses on mediolateral (ML) foot placement and its variability in sprinters with and without transtibial amputations. We hypothesized that ML foot placement variability would: 1. increase with running speed up to maximum speed and 2. be symmetrical between the legs of non-amputee sprinters but asymmetrically greater for the affected leg of sprinters with a unilateral transtibial amputation. We measured the midline of the body (kinematic data) and center of pressure (kinetic data) in the ML direction while 12 non-amputee sprinters and 7 Paralympic sprinters with transtibial amputations (6 unilateral, 1 bilateral) ran across a range of speeds up to maximum speed on a high-speed force measuring treadmill. We quantified ML foot placement relative to the body’s midline and its variability. We interpret our results with respect to a hypothesized relation between ML foot placement variability and lateral balance. We infer that greater ML foot placement variability indicates greater challenges with maintaining lateral balance. In non-amputee sprinters, ML foot placement variability for each leg increased substantially and symmetrically across speed. In sprinters with a unilateral amputation, ML foot placement variability for the affected and unaffected leg also increased substantially, but was asymmetric across speeds. In general, ML foot placement variability for sprinters with a unilateral amputation was within the range observed in non-amputee sprinters. For the sprinter with bilateral amputations, both affected legs exhibited the greatest increase in ML foot placement variability with speed. Overall, we find that maintaining lateral balance becomes increasingly challenging at faster speeds up to maximum speed but was equally challenging for sprinters with and without a unilateral transtibial amputation. Finally, when compared to all other sprinters in our subject pool, maintaining lateral balance appears to be the

Analysis of using EMG and mechanical sensors to enhance intent recognition in powered lower limb prostheses

NASA Astrophysics Data System (ADS)

Young, A. J.; Kuiken, T. A.; Hargrove, L. J.

2014-10-01

Objective. The purpose of this study was to determine the contribution of electromyography (EMG) data, in combination with a diverse array of mechanical sensors, to locomotion mode intent recognition in transfemoral amputees using powered prostheses. Additionally, we determined the effect of adding time history information using a dynamic Bayesian network (DBN) for both the mechanical and EMG sensors. Approach. EMG signals from the residual limbs of amputees have been proposed to enhance pattern recognition-based intent recognition systems for powered lower limb prostheses, but mechanical sensors on the prosthesis—such as inertial measurement units, position and velocity sensors, and load cells—may be just as useful. EMG and mechanical sensor data were collected from 8 transfemoral amputees using a powered knee/ankle prosthesis over basic locomotion modes such as walking, slopes and stairs. An offline study was conducted to determine the benefit of different sensor sets for predicting intent. Main results. EMG information was not as accurate alone as mechanical sensor information (p < 0.05) for any classification strategy. However, EMG in combination with the mechanical sensor data did significantly reduce intent recognition errors (p < 0.05) both for transitions between locomotion modes and steady-state locomotion. The sensor time history (DBN) classifier significantly reduced error rates compared to a linear discriminant classifier for steady-state steps, without increasing the transitional error, for both EMG and mechanical sensors. Combining EMG and mechanical sensor data with sensor time history reduced the average transitional error from 18.4% to 12.2% and the average steady-state error from 3.8% to 1.0% when classifying level-ground walking, ramps, and stairs in eight transfemoral amputee subjects. Significance. These results suggest that a neural interface in combination with time history methods for locomotion mode classification can enhance intent

Dating and intimate relationships of women with below-knee amputation: an exploratory study.

PubMed

Mathias, Zoë; Harcourt, Diana

2014-01-01

This study investigates experiences of dating and intimate relationships amongst women who use a below-knee prosthesis. Four women took part in semi-structured online interviews. Transcripts were subject to interpretative phenomenological analysis (IPA). Five themes were identified: Revealing and Exposing: Disclosing the Amputation and Prosthesis; Judging and Judged: Internal Fears and Self-Doubt; Trusting and Accepting: Good Guy/Bad Guy Elimination; Taking it Further: The Need for Depth; and Realisation: Accepting and Feeling Accepted. Participants described how, despite negative feelings towards their appearance and body image, they chose not to conceal their prosthesis when dating. Rather, it was used as a means of screening potential partners in their search for deep and meaningful relationships. Realising that others were not prejudiced towards people who use a prosthetic had helped them become more comfortable with their own prosthesis. These findings suggest that facilitating contact with other below-knee amputees and, in some cases specialist support, could help those who are struggling with the challenges they face regarding dating and intimate relationships. They also highlight the need for researchers and clinicians to give more attention to these important aspects of amputees' lives. Implications for Rehabilitation Amputation can have a significant psychosocial impact for those affected. The relative invisibility of below-knee amputation and prostheses can present particular challenges for amputees looking to establish romantic and intimate relationships, particularly around when and how to disclose the limb loss to potential partners. Developing a sense of resilience to the reactions of other people can help those who have undergone below-knee amputation. Support for people affected by below-knee amputation should routinely consider their needs and concerns in relation to new and established relationships, offer specialist psychosocial input when

Validation of the virtual elevation field test method when assessing the aerodynamics of para-cyclists with a uni-lateral trans-tibial amputation.

PubMed

Dyer, Bryce; Disley, B Xavier

2018-02-01

Lower-limb amputees typically require some form of prosthetic limb to ride a bicycle for recreation or when competing. At elite-level racing speeds, aerodynamic drag can represent the majority of the resistance acting against a cyclists' forward motion. As a result, the reduction of such resistance is beneficial to an amputee whereby the form and function of the prosthetic limb can be optimized through engineering. To measure the performance of such limbs, field testing provides a cost-effective and context-specific method of aerodynamic drag measurement. However, few methods have been formally validated and none have been applied to amputees with lower-limb amputations. In this paper, an elite level para-cyclist wore two different prosthetic limb designs and had their total aerodynamic drag of a wind tunnel reference method statistically correlated against a velodrome-based virtual elevation field test method. The calculated coefficient of variation was in the range of 0.7-0.9% for the wind tunnel method and 2-3% for the virtual elevation method. A 0.03 m 2 difference was identified in the absolute values recorded between the two methods. Ultimately, both methods exhibited high levels of precision, yet relative results to each other. The virtual elevation method is proposed as a suitable technique to assess the aerodynamic drag of amputee para-cyclists. Implications for rehabilitation This assessment method will provide practitioners a reliable means of assessing the impact of changes made to prosthetics design for cyclists with limb absence. The proposed method offers a low cost and geographically accessible solution compared to others proposed in the past. This assessment method has significant potential for impact among prosthetic limb users looking to improve their cycling performance whereas previous attention in this field has been extremely limited.

Open Targets: a platform for therapeutic target identification and validation

PubMed Central

Koscielny, Gautier; An, Peter; Carvalho-Silva, Denise; Cham, Jennifer A.; Fumis, Luca; Gasparyan, Rippa; Hasan, Samiul; Karamanis, Nikiforos; Maguire, Michael; Papa, Eliseo; Pierleoni, Andrea; Pignatelli, Miguel; Platt, Theo; Rowland, Francis; Wankar, Priyanka; Bento, A. Patrícia; Burdett, Tony; Fabregat, Antonio; Forbes, Simon; Gaulton, Anna; Gonzalez, Cristina Yenyxe; Hermjakob, Henning; Hersey, Anne; Jupe, Steven; Kafkas, Şenay; Keays, Maria; Leroy, Catherine; Lopez, Francisco-Javier; Magarinos, Maria Paula; Malone, James; McEntyre, Johanna; Munoz-Pomer Fuentes, Alfonso; O'Donovan, Claire; Papatheodorou, Irene; Parkinson, Helen; Palka, Barbara; Paschall, Justin; Petryszak, Robert; Pratanwanich, Naruemon; Sarntivijal, Sirarat; Saunders, Gary; Sidiropoulos, Konstantinos; Smith, Thomas; Sondka, Zbyslaw; Stegle, Oliver; Tang, Y. Amy; Turner, Edward; Vaughan, Brendan; Vrousgou, Olga; Watkins, Xavier; Martin, Maria-Jesus; Sanseau, Philippe; Vamathevan, Jessica; Birney, Ewan; Barrett, Jeffrey; Dunham, Ian

2017-01-01

We have designed and developed a data integration and visualization platform that provides evidence about the association of known and potential drug targets with diseases. The platform is designed to support identification and prioritization of biological targets for follow-up. Each drug target is linked to a disease using integrated genome-wide data from a broad range of data sources. The platform provides either a target-centric workflow to identify diseases that may be associated with a specific target, or a disease-centric workflow to identify targets that may be associated with a specific disease. Users can easily transition between these target- and disease-centric workflows. The Open Targets Validation Platform is accessible at https://www.targetvalidation.org. PMID:27899665

Combined mirror visual and auditory feedback therapy for upper limb phantom pain: a case report

PubMed Central

2011-01-01

Introduction Phantom limb sensation and phantom limb pain is a very common issue after amputations. In recent years there has been accumulating data implicating 'mirror visual feedback' or 'mirror therapy' as helpful in the treatment of phantom limb sensation and phantom limb pain. Case presentation We present the case of a 24-year-old Caucasian man, a left upper limb amputee, treated with mirror visual feedback combined with auditory feedback with improved pain relief. Conclusion This case may suggest that auditory feedback might enhance the effectiveness of mirror visual feedback and serve as a valuable addition to the complex multi-sensory processing of body perception in patients who are amputees. PMID:21272334

Hypoglossal-facial nerve anastomosis and rehabilitation in patients with complete facial palsy: cohort study of 30 patients followed up for three years

PubMed Central

Toffola, Elena Dalla; Pavese, Chiara; Cecini, Miriam; Petrucci, Lucia; Ricotti, Susanna; Bejor, Maurizio; Salimbeni, Grazia; Biglioli, Federico; Klersy, Catherine

2014-01-01

Summary Our study evaluates the grade and timing of recovery in 30 patients with complete facial paralysis (House-Brackmann grade VI) treated with hypoglossal-facial nerve (XII-VII) anastomosis and a long-term rehabilitation program, consisting of exercises in facial muscle activation mediated by tongue movement and synkinesis control with mirror feedback. Reinnervation after XII-VII anastomosis occurred in 29 patients, on average 5.4 months after surgery. Three years after the anastomosis, 23.3% of patients had grade II, 53.3% grade III, 20% grade IV and 3.3% grade VI ratings on the House-Brackmann scale. Time to reinnervation was associated with the final House-Brackmann grade. Our study demonstrates that patients undergoing XII-VII anastomosis and a long-term rehabilitation program display a significant recovery of facial symmetry and movement. The recovery continues for at least three years after the anastomosis, meaning that prolonged follow-up of these patients is advisable. PMID:25473738

Delivery of adipose-derived stem cells in poloxamer hydrogel improves peripheral nerve regeneration.

PubMed

Allbright, Kassandra O; Bliley, Jacqueline M; Havis, Emmanuelle; Kim, Deok-Yeol; Dibernardo, Gabriella A; Grybowski, Damian; Waldner, Matthias; James, Isaac B; Sivak, Wesley N; Rubin, J Peter; Marra, Kacey G

2018-02-06

Peripheral nerve damage is associated with high long-term morbidity. Because of beneficial secretome, immunomodulatory effects, and ease of clinical translation, transplantation with adipose-derived stem cells (ASC) represents a promising therapeutic modality. Effect of ASC delivery in poloxamer hydrogel was assessed in a rat sciatic nerve model of critical-sized (1.5 cm) peripheral nerve injury. Nerve/muscle unit regeneration was assessed via immunostaining explanted nerve, quantitative polymerase chain reaction (qPCR), and histological analysis of reinnervating gastrocnemius muscle. On the basis of viability data, 10% poloxamer hydrogel was selected for in vivo study. Six weeks after transection and repair, the group treated with poloxamer delivered ASCs demonstrated longest axonal regrowth. The qPCR results indicated that the inclusion of ASCs appeared to result in expression of factors that aid in reinnervating muscle tissue. Delivery of ASCs in poloxamer addresses multiple facets of the complexity of nerve/muscle unit regeneration, representing a promising avenue for further study. Muscle Nerve, 2018. © 2018 Wiley Periodicals, Inc.

Quantitative anal sphincter electromyography in primiparous women with anal incontinence

PubMed Central

Gregory, W. Thomas; Lou, Jau-Shin; Simmons, Kimberly; Clark, Amanda L.

2010-01-01

OBJECTIVE The purpose of this study was to determine whether evidence of denervation/reinnervation of the external anal sphincter is associated with anal incontinence symptoms immediately after delivery. STUDY DESIGN After a first vaginal delivery, 42 women completed an anal incontinence questionnaire. They also underwent concentric needle electromyography of the external anal sphincter. For each subject, motor unit action potential and interference pattern parameters were determined. RESULTS For the motor unit action potential, no difference was observed between patients with and without anal incontinence symptoms (t-test). For the interference pattern, the amplitude/turn was greater in subjects with fecal urgency (318 ± 48 [SD] μV) and fecal incontinence (332 ± 48 μV), compared with those without fecal urgency (282 ± 38 μV) and fecal incontinence (286 ± 41 μV; P = .02, t-test). CONCLUSION In this group of postpartum women with mild anal incontinence symptoms, interference pattern analysis shows evidence of denervation and subsequent reinnervation. PMID:18455531

Design and Development of a Novel Upper-Limb Cycling Prosthesis

PubMed Central

Soni-Sadar, Shivam; Rowbottom, Jack; Patel, Shilen; Mathewson, Edward; Pearson, Samuel; Hutchins, David; Head, John; Hutchins, Stephen

2017-01-01

The rise in popularity of the Paralympics in recent years has created a need for effective, low-cost sports-prosthetic devices for upper-limb amputees. There are various opportunities for lower-limb amputees to participate in cycling; however, there are only few options for those with upper-limb amputations. If the individual previously participated in cycling, a cycling-specific prosthesis could allow these activities to be integrated into rehabilitation methods. This article describes the processes involved with designing, developing and manufacturing such a prosthesis. The fundamental needs of people with upper-limb amputation were assessed and realised in the prototype of a transradial terminal device with two release mechanisms, including a sliding mechanism (for falls and minor collisions) and clamping mechanism (for head-on collisions). The sliding mechanism requires the rider to exert approximately 200 N, while the clamping mechanism requires about 700 N. The force ranges can be customised to match rider requirements. Experiments were conducted in a controlled environment to demonstrate stability of the device during normal cycling. Moreover, a volunteer test-rider was able to successfully activate the release mechanism during a simulated emergency scenario. The development of this prosthesis has the potential to enable traumatic upper-limb amputees to participate in cycling for rehabilitation or recreation. PMID:29144392

Self-Recalibrating Surface EMG Pattern Recognition for Neuroprosthesis Control Based on Convolutional Neural Network

PubMed Central

Zhai, Xiaolong; Jelfs, Beth; Chan, Rosa H. M.; Tin, Chung

2017-01-01

Hand movement classification based on surface electromyography (sEMG) pattern recognition is a promising approach for upper limb neuroprosthetic control. However, maintaining day-to-day performance is challenged by the non-stationary nature of sEMG in real-life operation. In this study, we propose a self-recalibrating classifier that can be automatically updated to maintain a stable performance over time without the need for user retraining. Our classifier is based on convolutional neural network (CNN) using short latency dimension-reduced sEMG spectrograms as inputs. The pretrained classifier is recalibrated routinely using a corrected version of the prediction results from recent testing sessions. Our proposed system was evaluated with the NinaPro database comprising of hand movement data of 40 intact and 11 amputee subjects. Our system was able to achieve ~10.18% (intact, 50 movement types) and ~2.99% (amputee, 10 movement types) increase in classification accuracy averaged over five testing sessions with respect to the unrecalibrated classifier. When compared with a support vector machine (SVM) classifier, our CNN-based system consistently showed higher absolute performance and larger improvement as well as more efficient training. These results suggest that the proposed system can be a useful tool to facilitate long-term adoption of prosthetics for amputees in real-life applications. PMID:28744189

Design and Development of a Novel Upper-Limb Cycling Prosthesis.

PubMed

Tiele, Akira; Soni-Sadar, Shivam; Rowbottom, Jack; Patel, Shilen; Mathewson, Edward; Pearson, Samuel; Hutchins, David; Head, John; Hutchins, Stephen

2017-11-16

The rise in popularity of the Paralympics in recent years has created a need for effective, low-cost sports-prosthetic devices for upper-limb amputees. There are various opportunities for lower-limb amputees to participate in cycling; however, there are only few options for those with upper-limb amputations. If the individual previously participated in cycling, a cycling-specific prosthesis could allow these activities to be integrated into rehabilitation methods. This article describes the processes involved with designing, developing and manufacturing such a prosthesis. The fundamental needs of people with upper-limb amputation were assessed and realised in the prototype of a transradial terminal device with two release mechanisms, including a sliding mechanism (for falls and minor collisions) and clamping mechanism (for head-on collisions). The sliding mechanism requires the rider to exert approximately 200 N, while the clamping mechanism requires about 700 N. The force ranges can be customised to match rider requirements. Experiments were conducted in a controlled environment to demonstrate stability of the device during normal cycling. Moreover, a volunteer test-rider was able to successfully activate the release mechanism during a simulated emergency scenario. The development of this prosthesis has the potential to enable traumatic upper-limb amputees to participate in cycling for rehabilitation or recreation.

Grasp specific and user friendly interface design for myoelectric hand prostheses.

PubMed

Mohammadi, Alireza; Lavranos, Jim; Howe, Rob; Choong, Peter; Oetomo, Denny

2017-07-01

This paper presents the design and characterisation of a hand prosthesis and its user interface, focusing on performing the most commonly used grasps in activities of daily living (ADLs). Since the operation of a multi-articulated powered hand prosthesis is difficult to learn and master, there is a significant rate of abandonment by amputees in preference for simpler devices. In choosing so, amputees chose to live with fewer features in their prosthesis that would more reliably perform the basic operations. In this paper, we look simultaneously at a hand prosthesis design method that aims for a small number of grasps, a low complexity user interface and an alternative method to the current use of EMG as a preshape selection method through the use of a simple button; to enable amputees to get to and execute the intended hand movements intuitively, quickly and reliably. An experiment is reported at the end of the paper comparing the speed and accuracy with which able-bodied naive subjects are able to select the intended preshapes through the use of a simplified EMG method and a simple button. It is shown that the button was significantly superior in the speed of successful task completion and marginally superior in accuracy (success of first attempt).

Perioperative and rehabilitation outcome after lower-limb amputation in elderly Chinese patients in Hong Kong.

PubMed

Leung, H B; Wong, W C; Wu, F C J; Guerin, J S

2004-06-01

Major amputation of the lower limb is considered the last resort when limb salvage is impossible. The aim of this study is to determine the morbidity, mortality, and rehabilitation outcome of patients that underwent a lower-limb amputation. A retrospective cohort study was conducted among 100 elderly patients who underwent a total of 120 lower-limb amputations in a regional hospital in Hong Kong from 1996 to 2001. The mean age of the amputees was 77.9 years; 58 were female. 95% of the amputations were performed because of infection with or without vascular compromise; 55 transfemoral and 60 transtibial amputations contributed 96% of the case mix. Some 43% of patients experienced early complications and 12% required re-amputation. The early (30-day) mortality rate was 15%. Only 55% of the amputees survived after 4 years. A 44% return-home rate was achieved. However, only 11% of the amputees could walk without help from other people. Although prostheses were issued to 42% of the survivors, compliance was only 53%; 24% of the survivors lost their remaining leg within 2 years. The outcome of major lower-extremity amputation remains poor. Efforts should be made to retain these limbs. When it is proven impossible, one should strive to preserve the knee joint whenever feasible.

Amputation rehabilitation and prosthetic restoration. From surgery to community reintegration.

PubMed

Esquenazi, Alberto

The purpose of this review is to summarize the literature related to the advances that have taken place in the management and rehabilitation care of limb amputation. Prostheses for the lower and upper limb amputee have changed greatly over the past several years, with advances in components, socket fabrication and fitting techniques, suspension systems and sources of power and electronic controls. Higher levels of limb amputation can now be fitted with functional prostheses, which allow more patients to achieve independent life styles. This is of particular importance for the multi-limb amputee. The rehabilitation of more traditional lower limb levels of amputation have also greatly benefited from the technological advances including energy storing feet, electronic control hydraulic knees, ankle rotators and shock absorbers to mention a few. For the upper limb amputee, myoelectric and proportional controlled terminal devices and elbow joints are now used routinely in some rehabilitation facilities. Experimental prosthetic fitting techniques and devices such as the use of osseo-implantation for suspension of the prosthesis, tension control hands or electromagnetic fluids for knee movement control will also be briefly discussed in this paper. It is possible to conclude from this review that many advances have occurred that have greatly impacted the functional outcomes of patients with limb amputation.

Self-Recalibrating Surface EMG Pattern Recognition for Neuroprosthesis Control Based on Convolutional Neural Network.

PubMed

Zhai, Xiaolong; Jelfs, Beth; Chan, Rosa H M; Tin, Chung

2017-01-01

Hand movement classification based on surface electromyography (sEMG) pattern recognition is a promising approach for upper limb neuroprosthetic control. However, maintaining day-to-day performance is challenged by the non-stationary nature of sEMG in real-life operation. In this study, we propose a self-recalibrating classifier that can be automatically updated to maintain a stable performance over time without the need for user retraining. Our classifier is based on convolutional neural network (CNN) using short latency dimension-reduced sEMG spectrograms as inputs. The pretrained classifier is recalibrated routinely using a corrected version of the prediction results from recent testing sessions. Our proposed system was evaluated with the NinaPro database comprising of hand movement data of 40 intact and 11 amputee subjects. Our system was able to achieve ~10.18% (intact, 50 movement types) and ~2.99% (amputee, 10 movement types) increase in classification accuracy averaged over five testing sessions with respect to the unrecalibrated classifier. When compared with a support vector machine (SVM) classifier, our CNN-based system consistently showed higher absolute performance and larger improvement as well as more efficient training. These results suggest that the proposed system can be a useful tool to facilitate long-term adoption of prosthetics for amputees in real-life applications.

Analysis of Interrelationships among Voluntary and Prosthetic Leg Joint Parameters Using Cyclograms.

PubMed

Jasni, Farahiyah; Hamzaid, Nur Azah; Mohd Syah, Nor Elleeiana; Chung, Tze Y; Abu Osman, Noor Azuan

2017-01-01

The walking mechanism of a prosthetic leg user is a tightly coordinated movement of several joints and limb segments. The interaction among the voluntary and mechanical joints and segments requires particular biomechanical insight. This study aims to analyze the inter-relationship between amputees' voluntary and mechanical coupled leg joints variables using cyclograms. From this analysis, the critical gait parameters in each gait phase were determined and analyzed if they contribute to a better powered prosthetic knee control design. To develop the cyclogram model, 20 healthy able-bodied subjects and 25 prosthesis and orthosis users (10 transtibial amputees, 5 transfemoral amputees, and 10 different pathological profiles of orthosis users) walked at their comfortable speed in a 3D motion analysis lab setting. The gait parameters (i.e., angle, moment and power for the ankle, knee and hip joints) were coupled to form 36 cyclograms relationship. The model was validated by quantifying the gait disparities of all the pathological walking by analyzing each cyclograms pairs using feed-forward neural network with backpropagation. Subsequently, the cyclogram pairs that contributed to the highest gait disparity of each gait phase were manipulated by replacing it with normal values and re-analyzed. The manipulated cyclograms relationship that showed highest improvement in terms of gait disparity calculation suggested that they are the most dominant parameters in powered-knee control. In case of transfemoral amputee walking, it was identified using this approach that at each gait sub-phase, the knee variables most responsible for closest to normal walking were: knee power during loading response and mid-stance, knee moment and knee angle during terminal stance phase, knee angle and knee power during pre-swing, knee angle at initial swing, and knee power at terminal swing. No variable was dominant during mid-swing phase implying natural pendulum effect of the lower limb between

Nuclease Target Site Selection for Maximizing On-target Activity and Minimizing Off-target Effects in Genome Editing

PubMed Central

Lee, Ciaran M; Cradick, Thomas J; Fine, Eli J; Bao, Gang

2016-01-01

The rapid advancement in targeted genome editing using engineered nucleases such as ZFNs, TALENs, and CRISPR/Cas9 systems has resulted in a suite of powerful methods that allows researchers to target any genomic locus of interest. A complementary set of design tools has been developed to aid researchers with nuclease design, target site selection, and experimental validation. Here, we review the various tools available for target selection in designing engineered nucleases, and for quantifying nuclease activity and specificity, including web-based search tools and experimental methods. We also elucidate challenges in target selection, especially in predicting off-target effects, and discuss future directions in precision genome editing and its applications. PMID:26750397

Reconstructive procedures for impaired upper airway function: laryngeal respiration

PubMed Central

Müller, Andreas

2005-01-01

The larynx is the "bottleneck" of the human airway. For this reason, the effects of stenosing laryngeal pathologies on the vital factor respiratory gas exchange are particularly critical. Internal stabilization is a prerequisite for recovery of the laryngeal respiratory function in severe forms of inspiratory collapse (laryngomalacia). Effective laser surgery techniques have been developed to this end in recent years. Glottis-dilating surgery in cases of bilateral vocal cord motion impairment is now moving in the direction of endoscopic laser cordotomy or cordectomy, whereas arytenoidectomy and open surgical procedures are now used only rarely due to higher secondary morbidity rates. In individual cases, in particular if functional recovery is expected, temporary laterofixation of a vocal cord using an endoscopic suturing technique can be a helpful approach. Extensive laryngeal defects can be covered by means of composite grafts with mucosal lining, a supporting skeleton and their own vascularization. Autologous transplantation of the larynx, with its complex surgical and immunological problems, has become a manageable procedure. The problems of post-transplantation reinnervation and risk assessment of immunosuppression-induced recurrence of the tumor are still under consideration. Reanimation of the bilaterally paralyzed larynx by means of neurorrhaphy (neurosuture), neural grafting and, more recently, functional electrostimulation (pacemaker) represents a challenge for the coming years. In most cases of paralysis of the recurrent laryngeal nerve, a part of the muscles is maintained by synkinetic reinnervation when therapy is carried out, which however also prevents effective vocal cord movement due to simultaneous activity of agonists and antagonists. Modulation of reinnervation by means of electrostimulation and modern genetic therapy approaches justify hopes of better outcomes in the future. PMID:22073057

Presynaptic NCAM Is Required for Motor Neurons to Functionally Expand Their Peripheral Field of Innervation in Partially Denervated Muscles

PubMed Central

Chipman, Peter H.; Schachner, Melitta

2014-01-01

The function of neural cell adhesion molecule (NCAM) expression in motor neurons during axonal sprouting and compensatory reinnervation was explored by partially denervating soleus muscles in mice lacking presynaptic NCAM (Hb9creNCAMflx). In agreement with previous studies, the contractile force of muscles in wild-type (NCAM+/+) mice recovered completely 2 weeks after 75% of the motor innervation was removed because motor unit size increased by 2.5 times. In contrast, similarly denervated muscles in Hb9creNCAMflx mice failed to recover the force lost due to the partial denervation because motor unit size did not change. Anatomical analysis indicated that 50% of soleus end plates were completely denervated 1–4 weeks post-partial denervation in Hb9creNCAMflx mice, while another 25% were partially reinnervated. Synaptic vesicles (SVs) remained at extrasynaptic regions in Hb9creNCAMflx mice rather than being distributed, as occurs normally, to newly reinnervated neuromuscular junctions (NMJs). Electrophysiological analysis revealed two populations of NMJs in partially denervated Hb9creNCAMflx soleus muscles, one with high (mature) quantal content, and another with low (immature) quantal content. Extrasynaptic SVs in Hb9creNCAMflx sprouts were associated with L-type voltage-dependent calcium channel (L-VDCC) immunoreactivity and maintained an immature, L-VDCC-dependent recycling phenotype. Moreover, acute nifedipine treatment potentiated neurotransmission at newly sprouted NMJs, while chronic intraperitoneal treatment with nifedipine during a period of synaptic consolidation enhanced functional motor unit expansion in the absence of presynaptic NCAM. We propose that presynaptic NCAM bridges a critical link between the SV cycle and the functional expansion of synaptic territory through the regulation of L-VDCCs. PMID:25100585

Literature evidence in open targets - a target validation platform.

PubMed

Kafkas, Şenay; Dunham, Ian; McEntyre, Johanna

2017-06-06

We present the Europe PMC literature component of Open Targets - a target validation platform that integrates various evidence to aid drug target identification and validation. The component identifies target-disease associations in documents and ranks the documents based on their confidence from the Europe PMC literature database, by using rules utilising expert-provided heuristic information. The confidence score of a given document represents how valuable the document is in the scope of target validation for a given target-disease association by taking into account the credibility of the association based on the properties of the text. The component serves the platform regularly with the up-to-date data since December, 2015. Currently, there are a total number of 1168365 distinct target-disease associations text mined from >26 million PubMed abstracts and >1.2 million Open Access full text articles. Our comparative analyses on the current available evidence data in the platform revealed that 850179 of these associations are exclusively identified by literature mining. This component helps the platform's users by providing the most relevant literature hits for a given target and disease. The text mining evidence along with the other types of evidence can be explored visually through https://www.targetvalidation.org and all the evidence data is available for download in json format from https://www.targetvalidation.org/downloads/data .

Study of target and non-target interplay in spatial attention task.

PubMed

Sweeti; Joshi, Deepak; Panigrahi, B K; Anand, Sneh; Santhosh, Jayasree

2018-02-01

Selective visual attention is the ability to selectively pay attention to the targets while inhibiting the distractors. This paper aims to study the targets and non-targets interplay in spatial attention task while subject attends to the target object present in one visual hemifield and ignores the distractor present in another visual hemifield. This paper performs the averaged evoked response potential (ERP) analysis and time-frequency analysis. ERP analysis agrees to the left hemisphere superiority over late potentials for the targets present in right visual hemifield. Time-frequency analysis performed suggests two parameters i.e. event-related spectral perturbation (ERSP) and inter-trial coherence (ITC). These parameters show the same properties for the target present in either of the visual hemifields but show the difference while comparing the activity corresponding to the targets and non-targets. In this way, this study helps to visualise the difference between targets present in the left and right visual hemifields and, also the targets and non-targets present in the left and right visual hemifields. These results could be utilised to monitor subjects' performance in brain-computer interface (BCI) and neurorehabilitation.

LIQUID TARGET

DOEpatents

Martin, M.D.; Salsig, W.W. Jr.

1959-01-13

A liquid handling apparatus is presented for a liquid material which is to be irradiated. The apparatus consists essentially of a reservoir for the liquid, a target element, a drain tank and a drain lock chamber. The target is in the form of a looped tube, the upper end of which is adapted to be disposed in a beam of atomic particles. The lower end of the target tube is in communication with the liquid in the reservoir and a means is provided to continuously circulate the liquid material to be irradiated through the target tube. Means to heat the reservoir tank is provided in the event that a metal is to be used as the target material. The apparatus is provided with suitable valves and shielding to provide maximum safety in operation.

Strategies to promote peripheral nerve regeneration: electrical stimulation and/or exercise

PubMed Central

Gordon, Tessa; English, Arthur W.

2015-01-01

Enhancing the regeneration of axons is often considered a therapeutic target for improving functional recovery after peripheral nerve injury. In this review, the evidence for the efficacy of electrical stimulation (ES), daily exercise, and their combination in promoting nerve regeneration after peripheral nerve injuries in both animal models and in human patients, is explored. The rationale, effectiveness, and molecular basis of ES and exercise in accelerating axon outgrowth are reviewed. In comparing the effects of ES and exercise in enhancing axon regeneration, increased neural activity, neurotrophins, and androgens are considered common requirements. Similar, gender-specific requirements are found for exercise to enhance axon regeneration in the periphery and for sustaining synaptic inputs onto injured motoneurons. ES promotes nerve regeneration after delayed nerve repair in humans and rats. The effectiveness of exercise is less clear. Although ES, but not exercise, results in a significant misdirection of regenerating motor axons to reinnervate different muscle targets, the loss of neuromuscular specificity encountered has only a very small impact on resulting functional recovery. Both ES and exercise are promising experimental treatments for peripheral nerve injury that seem ready to be translated to clinical use. PMID:26121368

Failure to expand the motor unit size to compensate for declining motor unit numbers distinguishes sarcopenic from non-sarcopenic older men.

PubMed

Piasecki, M; Ireland, A; Piasecki, J; Stashuk, D W; Swiecicka, A; Rutter, M K; Jones, D A; McPhee, J S

2018-05-01

The age-related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres. Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued. Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques. We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men. These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men. Sarcopenia results from the progressive loss of skeletal muscle mass and reduced function in older age. It is likely to be associated with the well-documented reduction of motor unit numbers innervating limb muscles and the increase in size of surviving motor units via reinnervation of denervated fibres. However, no evidence exists to confirm the extent of motor unit remodelling in sarcopenic individuals. The aim of the present study was to compare motor unit size and number between young (n = 48), non-sarcopenic old (n = 13), pre-sarcopenic (n = 53) and sarcopenic (n = 29) men. Motor unit potentials (MUPs) were isolated from intramuscular and surface EMG recordings. The motor unit numbers were reduced in all groups of old compared with young men (all P < 0.001). MUPs were higher in non-sarcopenic and pre-sarcopenic men compared with young men (P = 0.039 and 0.001 respectively), but not in the vastus lateralis of sarcopenic old (P = 0.485). The results suggest that extensive motor unit remodelling occurs relatively early during ageing, exceeds the loss of muscle mass and precedes sarcopenia. Reinnervation of denervated

SeedVicious: Analysis of microRNA target and near-target sites.

PubMed

Marco, Antonio

2018-01-01

Here I describe seedVicious, a versatile microRNA target site prediction software that can be easily fitted into annotation pipelines and run over custom datasets. SeedVicious finds microRNA canonical sites plus other, less efficient, target sites. Among other novel features, seedVicious can compute evolutionary gains/losses of target sites using maximum parsimony, and also detect near-target sites, which have one nucleotide different from a canonical site. Near-target sites are important to study population variation in microRNA regulation. Some analyses suggest that near-target sites may also be functional sites, although there is no conclusive evidence for that, and they may actually be target alleles segregating in a population. SeedVicious does not aim to outperform but to complement existing microRNA prediction tools. For instance, the precision of TargetScan is almost doubled (from 11% to ~20%) when we filter predictions by the distance between target sites using this program. Interestingly, two adjacent canonical target sites are more likely to be present in bona fide target transcripts than pairs of target sites at slightly longer distances. The software is written in Perl and runs on 64-bit Unix computers (Linux and MacOS X). Users with no computing experience can also run the program in a dedicated web-server by uploading custom data, or browse pre-computed predictions. SeedVicious and its associated web-server and database (SeedBank) are distributed under the GPL/GNU license.

The BADER Consortium

DTIC Science & Technology

2015-10-01

established use in  orthopedic /amputation  research  in amputee populations and have documented the relevant  research   on the psychometric properties and...established use in  orthopedic /amputation  research  in amputee populations have been identified.  The library has recently being updated  with recent...consult on the BIOM proposal and to review and discuss  research  agendas.    Core staff will schedule a meeting at WRNMMC to meet with  Orthopedic  and

Metabolics of stair ascent with a powered transfemoral prosthesis.

PubMed

Ledoux, E D; Lawson, B E; Shultz, A H; Bartlett, H L; Goldfarb, M

2015-01-01

This paper evaluates the effectiveness of a powered knee and ankle prosthesis for stair ascent through a metabolic assessment comparing energy expenditure of a single transfemoral amputee subject while ascending stairs with the powered prosthesis relative to his passive daily use device, as well as comparing the kinematics and kinetics obtained with the passive prosthesis to healthy biomechanics. The subject wore a portable system that measured pulmonary gaseous exchange rates of oxygen and carbon dioxide while he ascended stairs with each of the prostheses in alternating tests. The results indicated that the amputee's energy expenditure decreased by 32 percent while climbing with the powered prosthesis as compared to his passive one, and the kinematics and kinetics achieved were representative of healthy biomechanics.

Control of Prosthetic Hands via the Peripheral Nervous System

PubMed Central

Ciancio, Anna Lisa; Cordella, Francesca; Barone, Roberto; Romeo, Rocco Antonio; Bellingegni, Alberto Dellacasa; Sacchetti, Rinaldo; Davalli, Angelo; Di Pino, Giovanni; Ranieri, Federico; Di Lazzaro, Vincenzo; Guglielmelli, Eugenio; Zollo, Loredana

2016-01-01

This paper intends to provide a critical review of the literature on the technological issues on control and sensorization of hand prostheses interfacing with the Peripheral Nervous System (i.e., PNS), and their experimental validation on amputees. The study opens with an in-depth analysis of control solutions and sensorization features of research and commercially available prosthetic hands. Pros and cons of adopted technologies, signal processing techniques and motion control solutions are investigated. Special emphasis is then dedicated to the recent studies on the restoration of tactile perception in amputees through neural interfaces. The paper finally proposes a number of suggestions for designing the prosthetic system able to re-establish a bidirectional communication with the PNS and foster the prosthesis natural control. PMID:27092041

Electrically charged targets

DOEpatents

Goodman, Ronald K.; Hunt, Angus L.

1984-01-01

Electrically chargeable laser targets and method for forming such charged targets in order to improve their guidance along a predetermined desired trajectory. This is accomplished by the incorporation of a small amount of an additive to the target material which will increase the electrical conductivity thereof, and thereby enhance the charge placed upon the target material for guidance thereof by electrostatic or magnetic steering mechanisms, without adversely affecting the target when illuminated by laser energy.

The drug target genes show higher evolutionary conservation than non-target genes.

PubMed

Lv, Wenhua; Xu, Yongdeng; Guo, Yiying; Yu, Ziqi; Feng, Guanglong; Liu, Panpan; Luan, Meiwei; Zhu, Hongjie; Liu, Guiyou; Zhang, Mingming; Lv, Hongchao; Duan, Lian; Shang, Zhenwei; Li, Jin; Jiang, Yongshuai; Zhang, Ruijie

2016-01-26

Although evidence indicates that drug target genes share some common evolutionary features, there have been few studies analyzing evolutionary features of drug targets from an overall level. Therefore, we conducted an analysis which aimed to investigate the evolutionary characteristics of drug target genes. We compared the evolutionary conservation between human drug target genes and non-target genes by combining both the evolutionary features and network topological properties in human protein-protein interaction network. The evolution rate, conservation score and the percentage of orthologous genes of 21 species were included in our study. Meanwhile, four topological features including the average shortest path length, betweenness centrality, clustering coefficient and degree were considered for comparison analysis. Then we got four results as following: compared with non-drug target genes, 1) drug target genes had lower evolutionary rates; 2) drug target genes had higher conservation scores; 3) drug target genes had higher percentages of orthologous genes and 4) drug target genes had a tighter network structure including higher degrees, betweenness centrality, clustering coefficients and lower average shortest path lengths. These results demonstrate that drug target genes are more evolutionarily conserved than non-drug target genes. We hope that our study will provide valuable information for other researchers who are interested in evolutionary conservation of drug targets.

SECOND TARGET STATION MODERATOR PERFORMANCE WITH A ROTATING TARGET

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

Remec, Igor; Gallmeier, Franz X; Rennich, Mark J

2016-01-01

Oak Ridge National Laboratory manages and operates the Spallation Neutron Source and the High Flux Isotope Reactor, two of the world's most advanced neutron scattering facilities. Both facilities are funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science, and are available to researchers from all over the world. Delivering cutting edge science requires continuous improvements and development of the facilities and instruments. The SNS was designed from the outset to accommodate an additional target station, or Second Target Station (STS), and an upgraded accelerator feeding proton beams to STS and the existing First Targetmore » Station (FTS). Upgrade of the accelerator and the design and construction of STS are being proposed. The presently considered STS configuration is driven with short (<1 s) proton pulses at 10 Hz repetition rate and 467 kW proton beam power, and is optimized for high intensity and high resolution long wavelength neutron applications. STS will allow installation of 22 beamlines and will expand and complement the current national neutron scattering capabilities. In 2015 the STS studies were performed for a compact tungsten target; first a stationary tungsten plate target was analyzed to considerable details and then dropped in favor of a rotating target. For both target options the proton beam footprint as small as acceptable from mechanical and heat removal aspects is required to arrive at a compact-volume neutron production zone in the target, which is essential for tight coupling of target and moderators and for achieving high-intensity peak neutron fluxes. This paper will present recent STS work with the emphasis on neutronics and moderator performance.« less

Artificial limb representation in amputees

PubMed Central

van den Heiligenberg, Fiona M Z; Orlov, Tanya; Macdonald, Scott N; Duff, Eugene P; Henderson Slater, David; Beckmann, Christian F; Johansen-Berg, Heidi; Culham, Jody C; Makin, Tamar R

2018-01-01

Abstract The human brain contains multiple hand-selective areas, in both the sensorimotor and visual systems. Could our brain repurpose neural resources, originally developed for supporting hand function, to represent and control artificial limbs? We studied individuals with congenital or acquired hand-loss (hereafter one-handers) using functional MRI. We show that the more one-handers use an artificial limb (prosthesis) in their everyday life, the stronger visual hand-selective areas in the lateral occipitotemporal cortex respond to prosthesis images. This was found even when one-handers were presented with images of active prostheses that share the functionality of the hand but not necessarily its visual features (e.g. a ‘hook’ prosthesis). Further, we show that daily prosthesis usage determines large-scale inter-network communication across hand-selective areas. This was demonstrated by increased resting state functional connectivity between visual and sensorimotor hand-selective areas, proportional to the intensiveness of everyday prosthesis usage. Further analysis revealed a 3-fold coupling between prosthesis activity, visuomotor connectivity and usage, suggesting a possible role for the motor system in shaping use-dependent representation in visual hand-selective areas, and/or vice versa. Moreover, able-bodied control participants who routinely observe prosthesis usage (albeit less intensively than the prosthesis users) showed significantly weaker associations between degree of prosthesis observation and visual cortex activity or connectivity. Together, our findings suggest that altered daily motor behaviour facilitates prosthesis-related visual processing and shapes communication across hand-selective areas. This neurophysiological substrate for prosthesis embodiment may inspire rehabilitation approaches to improve usage of existing substitutionary devices and aid implementation of future assistive and augmentative technologies. PMID:29534154

Artificial limb representation in amputees.

PubMed

van den Heiligenberg, Fiona M Z; Orlov, Tanya; Macdonald, Scott N; Duff, Eugene P; Henderson Slater, David; Beckmann, Christian F; Johansen-Berg, Heidi; Culham, Jody C; Makin, Tamar R

2018-05-01

The human brain contains multiple hand-selective areas, in both the sensorimotor and visual systems. Could our brain repurpose neural resources, originally developed for supporting hand function, to represent and control artificial limbs? We studied individuals with congenital or acquired hand-loss (hereafter one-handers) using functional MRI. We show that the more one-handers use an artificial limb (prosthesis) in their everyday life, the stronger visual hand-selective areas in the lateral occipitotemporal cortex respond to prosthesis images. This was found even when one-handers were presented with images of active prostheses that share the functionality of the hand but not necessarily its visual features (e.g. a 'hook' prosthesis). Further, we show that daily prosthesis usage determines large-scale inter-network communication across hand-selective areas. This was demonstrated by increased resting state functional connectivity between visual and sensorimotor hand-selective areas, proportional to the intensiveness of everyday prosthesis usage. Further analysis revealed a 3-fold coupling between prosthesis activity, visuomotor connectivity and usage, suggesting a possible role for the motor system in shaping use-dependent representation in visual hand-selective areas, and/or vice versa. Moreover, able-bodied control participants who routinely observe prosthesis usage (albeit less intensively than the prosthesis users) showed significantly weaker associations between degree of prosthesis observation and visual cortex activity or connectivity. Together, our findings suggest that altered daily motor behaviour facilitates prosthesis-related visual processing and shapes communication across hand-selective areas. This neurophysiological substrate for prosthesis embodiment may inspire rehabilitation approaches to improve usage of existing substitutionary devices and aid implementation of future assistive and augmentative technologies.

Insurance Fairness for Amputees Act

THOMAS, 112th Congress

Sen. Snowe, Olympia J. [R-ME

2011-04-08

Senate - 04/08/2011 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Quality of life in survivors of a primary bone tumour: a systematic review.

PubMed

Eiser, C; Grimer, R J

1999-01-01

Purpose. We conducted a systematic search of published literature, to assess (i) quality of life (QoL) for survivors of a bone tumour compared with the normal population; (ii) QoL implications following amputation, successful or failed limb salvage; (iii) adaptation of young children to amputation compared with older children or adolescents.Methods. Electronic databases were searched including Medline, PsycLIT and Cinahl covering the years 1982- 1998.Results. We identified 11 studies. Regardless of treatment, physical functioning was poor compared with population norms or healthy siblings.There was less consistent evidence regarding emotional functioning. Seven studies compared functioning in amputees and limb salvage patients.Two reported advantages in physical function for the limb salvage group, one for the amputees and the rest no differences. Evidence about social functioning or marriage is inconclusive, but there are suggestions that amputees report more job discrimination.Discussion. The literature is inconclusive, largely because of methodological problems. These include small and non-representative samples, and lack of sensitive and appropriate measures. Specific gaps in the literature include very little work concerned with psychological outcomes for children, or for those experiencing failed limb salvage. More attention needs to be given to gender differences in emotional response to traumatic surgery.The implications of the results for helping families balance the merits of different treatments are discussed.

Memory for found targets interferes with subsequent performance in multiple-target visual search.

PubMed

Cain, Matthew S; Mitroff, Stephen R

2013-10-01

Multiple-target visual searches--when more than 1 target can appear in a given search display--are commonplace in radiology, airport security screening, and the military. Whereas 1 target is often found accurately, additional targets are more likely to be missed in multiple-target searches. To better understand this decrement in 2nd-target detection, here we examined 2 potential forms of interference that can arise from finding a 1st target: interference from the perceptual salience of the 1st target (a now highly relevant distractor in a known location) and interference from a newly created memory representation for the 1st target. Here, we found that removing found targets from the display or making them salient and easily segregated color singletons improved subsequent search accuracy. However, replacing found targets with random distractor items did not improve subsequent search accuracy. Removing and highlighting found targets likely reduced both a target's visual salience and its memory load, whereas replacing a target removed its visual salience but not its representation in memory. Collectively, the current experiments suggest that the working memory load of a found target has a larger effect on subsequent search accuracy than does its perceptual salience. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Internal Targeting and External Control: Phototriggered Targeting in Nanomedicine.

PubMed

Arrue, Lily; Ratjen, Lars

2017-12-07

The photochemical control of structure and reactivity bears great potential for chemistry, biology, and life sciences. A key feature of photochemistry is the spatiotemporal control over secondary events. Well-established applications of photochemistry in medicine are photodynamic therapy (PDT) and photopharmacology (PP). However, although both are highly localizable through the application of light, they lack cell- and tissue-specificity. The combination of nanomaterial-based drug delivery and targeting has the potential to overcome limitations for many established therapy concepts. Even more privileged seems the merger of nanomedicine and cell-specific targeting (internal targeting) controlled by light (external control), as it can potentially be applied to many different areas of medicine and pharmaceutical research, including the aforementioned PDT and PP. In this review a survey of the interface of photochemistry, medicine and targeted drug delivery is given, especially focusing on phototriggered targeting in nanomedicine. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design, in vitro and in vivo assessment of a multi-channel sieve electrode with integrated multiplexer.

PubMed

Ramachandran, Anup; Schuettler, Martin; Lago, Natalia; Doerge, Thomas; Koch, Klaus Peter; Navarro, Xavier; Hoffmann, Klaus-Peter; Stieglitz, Thomas

2006-06-01

This paper reports on the design, in vitro and in vivo investigation of a flexible, lightweight, polyimide based implantable sieve electrode with a hybrid assembly of multiplexers and polymer encapsulation. The integration of multiplexers enables us to connect a large number of electrodes on the sieve using few input connections. The implant assembly of the sieve electrode with the electronic circuitry was verified by impedance measurement. The 27 platinum electrodes of the sieve were coated with platinum black to reduce the electrode impedance. The impedance magnitude of the electrode sites on the sieve (geometric surface area 2,200 microm(2)) was |Z(f=1kHz)| = 5.7 kOmega. The sieve electrodes, encased in silicone, have been implanted in the transected sciatic nerve of rats. Initial experiments showed that axons regenerated through the holes of the sieve and reinnervated distal target organs. Nerve signals were recorded in preliminary tests after 3-7 months post-implantation.

Dual-targeting siRNAs

PubMed Central

Tiemann, Katrin; Höhn, Britta; Ehsani, Ali; Forman, Stephen J.; Rossi, John J.; Sætrom, Pål

2010-01-01

We have developed an algorithm for the prediction of dual-targeting short interfering RNAs (siRNAs) in which both strands are deliberately designed to separately target different mRNA transcripts with complete complementarity. An advantage of this approach versus the use of two separate duplexes is that only two strands, as opposed to four, are competing for entry into the RNA-induced silencing complex. We chose to design our dual-targeting siRNAs as Dicer substrate 25/27mer siRNAs, since design features resembling pre-microRNAs (miRNAs) can be introduced for Dicer processing. Seven different dual-targeting siRNAs targeting genes that are potential targets in cancer therapy have been developed including Bcl2, Stat3, CCND1, BIRC5, and MYC. The dual-targeting siRNAs have been characterized for dual target knockdown in three different cell lines (HEK293, HCT116, and PC3), where they were as effective as their corresponding single-targeting siRNAs in target knockdown. The algorithm developed in this study should prove to be useful for predicting dual-targeting siRNAs in a variety of different targets and is available from http://demo1.interagon.com/DualTargeting/. PMID:20410240

In vivo confocal microscopic investigation of the cornea after autologous implantation of lenticules obtained through small incision lenticule extraction for treatment of hyperopia.

PubMed

Li, Meiyan; Li, Meng; Sun, Ling; Han, Tian; Ding, Lan; Xiang, Jun; Zhou, Xingtao

2018-01-01

To investigate re-innervation in the implanted lenticule, as well as changes to the cornea, after correcting hyperopia with an autologous implantation of a lenticule obtained through small incision lenticule extraction (SMILE). This study retrospectively analysed re-innervation in the implanted lenticule, as well as microscopic morphological changes in the corneal architecture of the recipient cornea in five patients (with myopia in one eye and hyperopia in the contralateral eye) who received SMILE in the myopic eye and femtosecond laser in situ keratomileusis (FS-LASIK) combined with lenticule implantation in the contralateral hyperopic eye. Re-innervation in the implanted lenticule, as well as microscopic morphological changes in corneal architecture, were evaluated by in vivo confocal microscopy. One patient was examined at postoperative week six, two were examined at postoperative month two, one was examined at postoperative month nine, and one was examined at postoperative month 12. Partial subbasal nerve fibre regeneration was detected in two patients (Case 4 who was examined at postoperative month nine and Case 5 who was examined at postoperative month 12). Regenerated and branched nerve fibres were detected in the implanted lenticule in Case 5 who was examined at postoperative month 12. Both the anterior and posterior interfaces showed an absence or decrease of keratocytes and the presence of small particles of various brightnesses. Keratocytes in the implanted lenticule presented abnormal morphology in size and shape after surgery in all treated eyes, but showed partial morphological recovery in two patients (Case 4 who was examined at postoperative month nine and Case 5 who was examined at postoperative month 12). These preliminary findings suggest that nerve fibres will regenerate into the implanted lenticule after autologous lenticule implantation. Keratocytes in lenticules demonstrated a gradual return to a normal morphology. © 2017 Optometry

Permanent central synaptic disconnection of proprioceptors after nerve injury and regeneration. I. Loss of VGLUT1/IA synapses on motoneurons

PubMed Central

Titus-Mitchell, Haley E.; Bullinger, Katie L.; Kraszpulski, Michal; Nardelli, Paul; Cope, Timothy C.

2011-01-01

Motor and sensory proprioceptive axons reinnervate muscles after peripheral nerve transections followed by microsurgical reattachment; nevertheless, motor coordination remains abnormal and stretch reflexes absent. We analyzed the possibility that permanent losses of central IA afferent synapses, as a consequence of peripheral nerve injury, are responsible for this deficit. VGLUT1 was used as a marker of proprioceptive synapses on rat motoneurons. After nerve injuries synapses are stripped from motoneurons, but while other excitatory and inhibitory inputs eventually recover, VGLUT1 synapses are permanently lost on the cell body (75–95% synaptic losses) and on the proximal 100 μm of dendrite (50% loss). Lost VGLUT1 synapses did not recover, even many months after muscle reinnervation. Interestingly, VGLUT1 density in more distal dendrites did not change. To investigate whether losses are due to VGLUT1 downregulation in injured IA afferents or to complete synaptic disassembly and regression of IA ventral projections, we studied the central trajectories and synaptic varicosities of axon collaterals from control and regenerated afferents with IA-like responses to stretch that were intracellularly filled with neurobiotin. VGLUT1 was present in all synaptic varicosities, identified with the synaptic marker SV2, of control and regenerated afferents. However, regenerated afferents lacked axon collaterals and synapses in lamina IX. In conjunction with the companion electrophysiological study [Bullinger KL, Nardelli P, Pinter MJ, Alvarez FJ, Cope TC. J Neurophysiol (August 10, 2011). doi:10.1152/jn.01097.2010], we conclude that peripheral nerve injuries cause a permanent retraction of IA afferent synaptic varicosities from lamina IX and disconnection with motoneurons that is not recovered after peripheral regeneration and reinnervation of muscle by sensory and motor axons. PMID:21832035

Abdominal morbidity after single- versus double-pedicled deep inferior epigastric perforator flap use.

PubMed

Uda, Hirokazu; Tomioka, Yoko Katsuragi; Sarukawa, Syunji; Sunaga, Ataru; Kamochi, Hideaki; Sugawara, Yasusih; Yoshimura, Kotaro

2016-09-01

The reduced incidence of donor site morbidity after deep inferior epigastric perforator (DIEP) flap is because the rectus muscle and its fascia are preserved. However, no study has proved that trunk flexion recovers not by the compensatory effect of the contralateral rectus muscle but by reinnervation of the ipsilateral rectus muscle. We hypothesized that if sufficient reinnervation occurs, patients who undergo single-pedicled DIEP (S-DIEP) flap or double-pedicled DIEP (D-DIEP) flap breast reconstruction would have similar levels of preoperative trunk flexion. To determine this, we investigated perioperative changes in trunk flexor muscle ability quantitatively using an isokinetic dynamometer in patients who had received S-DIEP or D-DIEP. Patients who underwent breast reconstruction with S-DIEP (n = 37) and D-DIEP (n = 30) were included in this study. Pre- and postoperative trunk flexor muscle ability was measured prospectively by an isokinetic dynamometer in all patients. Postoperative abdominal pain and stiffness, patients' activity, and incidence of bulging were also investigated. Six months after surgery, the trunk flexor muscle ability recovered and did not significantly decrease subsequently in either group. This finding was consistent with the result that patients' activities and the incidence of bulging were similar between the two groups. Our results show that reinnervation of the rectus muscle can be confirmed at 6 months after DIEP flap elevation. Thus, we recommend D-DIEP flap without concern for abdominal wall weakness, especially in patients with multiple abdominal scars and who require breast tissue exceeding the amount of tissue that can be transferred with S-DIEP flap. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Quantitative facial electromyography monitoring after hypoglossal‐facial jump nerve suture

PubMed Central

Flasar, Jan; Volk, Gerd Fabian; Granitzka, Thordis; Geißler, Katharina; Irintchev, Andrey; Lehmann, Thomas

2017-01-01

Objectives/Hypothesis The time course of the reinnervation of the paralyzed face after hypoglossal‐facial jump nerve suture using electromyography (EMG) was assessed. The relation to the clinical outcome was analyzed. Study Design Retrospective single‐center cohort study Methods Reestablishment of motor units was studied by quantitative EMG and motor unit potential (MUP) analysis in 11 patients after hypoglossal‐facial jump nerve suture. Functional recovery was evaluated using the Stennert index (0 = normal; 10 = maximal palsy). Results Clinically, first movements were seen between 6 and >10 months after surgery in individual patients. Maximal improvement was achieved at 18 months. The Stennert index decreased from 7.9 ± 2.0 preoperatively to a final postoperative score of 5.8 ± 2.4. EMG monitoring performed for 2.8 to 60 months after surgery revealed that pathological spontaneous activity disappeared within 2 weeks. MUPs were first recorded after the 2nd month and present in all 11 patients 8–10 months post‐surgery. Polyphasic regeneration potentials first appeared at 4–10 months post‐surgery. The MUP amplitudes increased between the 3rd and 15th months after surgery to values of control muscles. The MUP duration was significantly increased above normal values between the 3rd and 24th months after surgery. Conclusion Reinnervation can be detected at least 2 months earlier by EMG than by clinical evaluation. Changes should be followed for at least 18 months to assess outcome. EMG changes reflected the remodeling of motor units due to axonal regeneration and collateral sprouting by hypoglossal nerve fibers into the reinnervated facial muscle fibers. Level of Evidence 3b. PMID:29094077

Development of a residuum/socket interface simulator for lower limb prosthetics.

PubMed

McGrath, Michael Paul; Gao, Jianliang; Tang, Jinghua; Laszczak, Piotr; Jiang, Liudi; Bader, Dan; Moser, David; Zahedi, Saeed

2017-03-01

Mechanical coupling at the interface between lower limb residua and prosthetic sockets plays an important role in assessing socket fitting and tissue health. However, most research lab-based lower limb prosthetic simulators to-date have implemented a rigid socket coupling. This study describes the fabrication and implementation of a lower limb residuum/socket interface simulator, designed to reproduce the forces and moments present during the key loading phases of amputee walking. An artificial residuum made with model bones encased in silicone was used, mimicking the compliant mechanical loading of a real residuum/socket interface. A 6-degree-of-freedom load cell measured the overall kinetics, having previously been incorporated into an amputee's prosthesis to collect reference data. The developed simulator was compared to a setup where a rigid pylon replaced the artificial residuum. A maximum uniaxial load of 850 N was applied, comparable to the peak vertical ground reaction force component during amputee walking. Load cell outputs from both pylon and residuum setups were compared. During weight acceptance, when including the artificial residuum, compression decreased by 10%, while during push off, sagittal bending and anterior-posterior shear showed a 25% increase and 34% decrease, respectively. Such notable difference by including a compliant residuum further highlighted the need for such an interface simulator. Subsequently, the simulator was adjusted to produce key load cell outputs briefly aligning with those from amputee walking. Force sensing resistors were deployed at load bearing anatomic locations on the residuum/socket interface to measure pressures and were compared to those cited in the literature for similar locations. The development of such a novel simulator provides an objective adjunct, using commonly available mechanical test machines. It could potentially be used to provide further insight into socket design, fit and the complex load

The SmartHand transradial prosthesis

PubMed Central

2011-01-01

Background Prosthetic components and control interfaces for upper limb amputees have barely changed in the past 40 years. Many transradial prostheses have been developed in the past, nonetheless most of them would be inappropriate if/when a large bandwidth human-machine interface for control and perception would be available, due to either their limited (or inexistent) sensorization or limited dexterity. SmartHand tackles this issue as is meant to be clinically experimented in amputees employing different neuro-interfaces, in order to investigate their effectiveness. This paper presents the design and on bench evaluation of the SmartHand. Methods SmartHand design was bio-inspired in terms of its physical appearance, kinematics, sensorization, and its multilevel control system. Underactuated fingers and differential mechanisms were designed and exploited in order to fit all mechatronic components in the size and weight of a natural human hand. Its sensory system was designed with the aim of delivering significant afferent information to the user through adequate interfaces. Results SmartHand is a five fingered self-contained robotic hand, with 16 degrees of freedom, actuated by 4 motors. It integrates a bio-inspired sensory system composed of 40 proprioceptive and exteroceptive sensors and a customized embedded controller both employed for implementing automatic grasp control and for potentially delivering sensory feedback to the amputee. It is able to perform everyday grasps, count and independently point the index. The weight (530 g) and speed (closing time: 1.5 seconds) are comparable to actual commercial prostheses. It is able to lift a 10 kg suitcase; slippage tests showed that within particular friction and geometric conditions the hand is able to stably grasp up to 3.6 kg cylindrical objects. Conclusions Due to its unique embedded features and human-size, the SmartHand holds the promise to be experimentally fitted on transradial amputees and employed as a bi

SuperTarget and Matador: resources for exploring drug-target relationships.

PubMed

Günther, Stefan; Kuhn, Michael; Dunkel, Mathias; Campillos, Monica; Senger, Christian; Petsalaki, Evangelia; Ahmed, Jessica; Urdiales, Eduardo Garcia; Gewiess, Andreas; Jensen, Lars Juhl; Schneider, Reinhard; Skoblo, Roman; Russell, Robert B; Bourne, Philip E; Bork, Peer; Preissner, Robert

2008-01-01

The molecular basis of drug action is often not well understood. This is partly because the very abundant and diverse information generated in the past decades on drugs is hidden in millions of medical articles or textbooks. Therefore, we developed a one-stop data warehouse, SuperTarget that integrates drug-related information about medical indication areas, adverse drug effects, drug metabolization, pathways and Gene Ontology terms of the target proteins. An easy-to-use query interface enables the user to pose complex queries, for example to find drugs that target a certain pathway, interacting drugs that are metabolized by the same cytochrome P450 or drugs that target the same protein but are metabolized by different enzymes. Furthermore, we provide tools for 2D drug screening and sequence comparison of the targets. The database contains more than 2500 target proteins, which are annotated with about 7300 relations to 1500 drugs; the vast majority of entries have pointers to the respective literature source. A subset of these drugs has been annotated with additional binding information and indirect interactions and is available as a separate resource called Matador. SuperTarget and Matador are available at http://insilico.charite.de/supertarget and http://matador.embl.de.

About miRNAs, miRNA seeds, target genes and target pathways.

PubMed

Kehl, Tim; Backes, Christina; Kern, Fabian; Fehlmann, Tobias; Ludwig, Nicole; Meese, Eckart; Lenhof, Hans-Peter; Keller, Andreas

2017-12-05

miRNAs are typically repressing gene expression by binding to the 3' UTR, leading to degradation of the mRNA. This process is dominated by the eight-base seed region of the miRNA. Further, miRNAs are known not only to target genes but also to target significant parts of pathways. A logical line of thoughts is: miRNAs with similar (seed) sequence target similar sets of genes and thus similar sets of pathways. By calculating similarity scores for all 3.25 million pairs of 2,550 human miRNAs, we found that this pattern frequently holds, while we also observed exceptions. Respective results were obtained for both, predicted target genes as well as experimentally validated targets. We note that miRNAs target gene set similarity follows a bimodal distribution, pointing at a set of 282 miRNAs that seems to target genes with very high specificity. Further, we discuss miRNAs with different (seed) sequences that nonetheless regulate similar gene sets or pathways. Most intriguingly, we found miRNA pairs that regulate different gene sets but similar pathways such as miR-6886-5p and miR-3529-5p. These are jointly targeting different parts of the MAPK signaling cascade. The main goal of this study is to provide a general overview on the results, to highlight a selection of relevant results on miRNAs, miRNA seeds, target genes and target pathways and to raise awareness for artifacts in respective comparisons. The full set of information that allows to infer detailed results on each miRNA has been included in miRPathDB, the miRNA target pathway database (https://mpd.bioinf.uni-sb.de).

Current Treatment Options for Bilateral Vocal Fold Paralysis: A State-of-the-Art Review

PubMed Central

Li, Yike; Garrett, Gaelyn; Zealear, David

2017-01-01

Vocal fold paralysis (VFP) refers to neurological causes of reduced or absent movement of one or both vocal folds. Bilateral VFP (BVFP) is characterized by inspiratory dyspnea due to narrowing of the airway at the glottic level with both vocal folds assuming a paramedian position. The primary objective of intervention for BVFP is to relieve patients’ dyspnea. Common clinical options for management include tracheostomy, arytenoidectomy and cordotomy. Other options that have been used with varying success include reinnervation techniques and botulinum toxin (Botox) injections into the vocal fold adductors. More recently, research has focused on neuromodulation, laryngeal pacing, gene therapy, and stem cell therapy. These newer approaches have the potential advantage of avoiding damage to the voicing mechanism of the larynx with an added goal of restoring some physiologic movement of the affected vocal folds. However, clinical data are scarce for these new treatment options (i.e., reinnervation and pacing), so more investigative work is needed. These areas of research are expected to provide dramatic improvements in the treatment of BVFP. PMID:28669149

Quantification and characterization of grouped type I myofibers in human aging.

PubMed

Kelly, Neil A; Hammond, Kelley G; Stec, Michael J; Bickel, C Scott; Windham, Samuel T; Tuggle, S Craig; Bamman, Marcas M

2018-01-01

Myofiber type grouping is a histological hallmark of age-related motor unit remodeling. Despite the accepted concept that denervation-reinnervation events lead to myofiber type grouping, the completeness of those conversions remains unknown. Type I myofiber grouping was assessed in vastus lateralis biopsies from Young (26 ± 4 years; n = 27) and Older (66 ± 4 years; n = 91) adults. Grouped and ungrouped type I myofibers were evaluated for phenotypic differences. Higher type I grouping in Older versus Young was driven by more myofibers per group (i.e., larger group size) (P < 0.05). In Older only, grouped type I myofibers displayed larger cross-sectional area, more myonuclei, lower capillary supply, and more sarco(endo)plasmic reticulum calcium ATPase I (SERCA I) expression (P < 0.05) than ungrouped type I myofibers. Grouped type I myofibers retain type II characteristics suggesting that conversion during denervation-reinnervation events is either progressive or incomplete. Muscle Nerve 57: E52-E59, 2018. © 2017 Wiley Periodicals, Inc.

Changing central nervous system control following intercostal nerve transfer.

PubMed

Malessy, M J; Thomeer, R T; van Dijk, J G

1998-10-01

The goal of this study was to find which central nervous system (CNS) pathways are involved in volitional control over reinnervated biceps or pectoral muscles. Intercostal nerves (ICNs) were coapted to the musculocutaneous nerve (MCN) or the medial pectoral nerve (MPN) in 23 patients with root avulsions of the brachial plexus to restore biceps or pectoral muscle function. The facilitatory effects of respiration and voluntary contraction on cortical motor-evoked potentials of biceps or pectoral muscles were used to study CNS control over the reinnervated muscles. The time course of the facilitatory effect of respiration and voluntary contraction differed significantly. In the end stage of nerve regeneration, the facilitatory effect of voluntary contraction was significantly larger than that of respiration, indicating that the CNS control network over the muscle comes to resemble that of the recipient nerve (MCN or MPN) rather than that of the donor nerve (ICN). The strengthening of previously subthreshold synaptic connections in a CNS network connecting ICN to MCN or MPN neurons may underlie changing excitability.

3D reconstruction and heat map of porcine recurrent laryngeal nerve anatomy: branching and spatial location.

PubMed

Mason, Nena Lundgreen; Christiansen, Marc; Wisco, Jonathan J

2015-01-01

Recurrent laryngeal nerve palsy is a common post-operative complication of many head and neck surgeries. Theoretically, the best treatment to restore partial function to a damaged recurrent laryngeal nerve would be reinnervation of the posterior cricoarytenoid muscle via anastomosis of the recurrent laryngeal and phrenic nerves. The pig is an excellent model of human laryngeal anatomy and physiology but a more thorough knowledge of porcine laryngeal anatomy is necessary before the pig can be used to improve existing surgical strategies, and develop new ones. This study first identifies the three most common recurrent laryngeal nerve branching patterns in the pig. Secondly, this study presents three-dimensional renderings of the porcine larynx onto which the recurrent laryngeal nerve patterns are accurately mapped. Lastly, heat maps are presented to display the spatial variability of recurrent laryngeal nerve trunks and primary branches on each side of 15 subjects (28 specimens). We intend for this study to be useful to groups using a porcine model to study posterior cricoarytenoid muscle reinnervation techniques.

A Prosthetic Hand Body Area Controller Based on Efficient Pattern Recognition Control Strategies.

PubMed

Benatti, Simone; Milosevic, Bojan; Farella, Elisabetta; Gruppioni, Emanuele; Benini, Luca

2017-04-15

Poliarticulated prosthetic hands represent a powerful tool to restore functionality and improve quality of life for upper limb amputees. Such devices offer, on the same wearable node, sensing and actuation capabilities, which are not equally supported by natural interaction and control strategies. The control in state-of-the-art solutions is still performed mainly through complex encoding of gestures in bursts of contractions of the residual forearm muscles, resulting in a non-intuitive Human-Machine Interface (HMI). Recent research efforts explore the use of myoelectric gesture recognition for innovative interaction solutions, however there persists a considerable gap between research evaluation and implementation into successful complete systems. In this paper, we present the design of a wearable prosthetic hand controller, based on intuitive gesture recognition and a custom control strategy. The wearable node directly actuates a poliarticulated hand and wirelessly interacts with a personal gateway (i.e., a smartphone) for the training and personalization of the recognition algorithm. Through the whole system development, we address the challenge of integrating an efficient embedded gesture classifier with a control strategy tailored for an intuitive interaction between the user and the prosthesis. We demonstrate that this combined approach outperforms systems based on mere pattern recognition, since they target the accuracy of a classification algorithm rather than the control of a gesture. The system was fully implemented, tested on healthy and amputee subjects and compared against benchmark repositories. The proposed approach achieves an error rate of 1.6% in the end-to-end real time control of commonly used hand gestures, while complying with the power and performance budget of a low-cost microcontroller.

A Prosthetic Hand Body Area Controller Based on Efficient Pattern Recognition Control Strategies

PubMed Central

Benatti, Simone; Milosevic, Bojan; Farella, Elisabetta; Gruppioni, Emanuele; Benini, Luca

2017-01-01

Poliarticulated prosthetic hands represent a powerful tool to restore functionality and improve quality of life for upper limb amputees. Such devices offer, on the same wearable node, sensing and actuation capabilities, which are not equally supported by natural interaction and control strategies. The control in state-of-the-art solutions is still performed mainly through complex encoding of gestures in bursts of contractions of the residual forearm muscles, resulting in a non-intuitive Human-Machine Interface (HMI). Recent research efforts explore the use of myoelectric gesture recognition for innovative interaction solutions, however there persists a considerable gap between research evaluation and implementation into successful complete systems. In this paper, we present the design of a wearable prosthetic hand controller, based on intuitive gesture recognition and a custom control strategy. The wearable node directly actuates a poliarticulated hand and wirelessly interacts with a personal gateway (i.e., a smartphone) for the training and personalization of the recognition algorithm. Through the whole system development, we address the challenge of integrating an efficient embedded gesture classifier with a control strategy tailored for an intuitive interaction between the user and the prosthesis. We demonstrate that this combined approach outperforms systems based on mere pattern recognition, since they target the accuracy of a classification algorithm rather than the control of a gesture. The system was fully implemented, tested on healthy and amputee subjects and compared against benchmark repositories. The proposed approach achieves an error rate of 1.6% in the end-to-end real time control of commonly used hand gestures, while complying with the power and performance budget of a low-cost microcontroller. PMID:28420135

The Human Kinome Targeted by FDA Approved Multi-Target Drugs and Combination Products: A Comparative Study from the Drug-Target Interaction Network Perspective.

PubMed

Li, Ying Hong; Wang, Pan Pan; Li, Xiao Xu; Yu, Chun Yan; Yang, Hong; Zhou, Jin; Xue, Wei Wei; Tan, Jun; Zhu, Feng

2016-01-01

The human kinome is one of the most productive classes of drug target, and there is emerging necessity for treating complex diseases by means of polypharmacology (multi-target drugs and combination products). However, the advantages of the multi-target drugs and the combination products are still under debate. A comparative analysis between FDA approved multi-target drugs and combination products, targeting the human kinome, was conducted by mapping targets onto the phylogenetic tree of the human kinome. The approach of network medicine illustrating the drug-target interactions was applied to identify popular targets of multi-target drugs and combination products. As identified, the multi-target drugs tended to inhibit target pairs in the human kinome, especially the receptor tyrosine kinase family, while the combination products were able to against targets of distant homology relationship. This finding asked for choosing the combination products as a better solution for designing drugs aiming at targets of distant homology relationship. Moreover, sub-networks of drug-target interactions in specific disease were generated, and mechanisms shared by multi-target drugs and combination products were identified. In conclusion, this study performed an analysis between approved multi-target drugs and combination products against the human kinome, which could assist the discovery of next generation polypharmacology.

Finite element analysis of the contact interface between trans-femoral stump and prosthetic socket.

PubMed

Zhang, Linlin; Zhu, Ming; Shen, Ling; Zheng, Feng

2013-01-01

Transfemoral amputees need prosthetic devices after amputation surgery, and the interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. The purpose of this study was to build a nonlinear finite element model to investigate the interface pressure between the above-knee residual limb and its prosthetic socket. The model was three-dimensional (3D) with consideration of nonlinear boundary conditions. Contact analysis was used to simulate the friction conditions between skin and the socket. The normal stresses up to 80.57 kPa at the distal end of the soft tissue. The longitudinal and circumferential shear stress distributions at the limb-socket interface were also simulated. This study explores the influences of load transfer between trans-femoral residual limb and its prosthetic socket.

Treatment for the service member: a description of innovative interventions.

PubMed

Yancosek, Katie; Daugherty, Stephanie E; Cancio, Leonard

2008-01-01

This article describes advances to the rehabilitation programs at major military medical centers since the onset of operations in Iraq and Afghanistan. The demands on military health care in times of war produce advances in the various rehabilitation professions. This article describes two programs that use new technologies for the care of military patients with devastating injuries to the upper extremity. One project relates to the application of voice-sensitive technology. The other project describes the utilization of virtual reality technology through a Firearm Training System. The article also explains an adaptive sports program and how recreation is part of a robust community reintegration program. Lastly, this article discusses the Center for the Intrepid, which is one of two new amputee care centers built to support the advanced rehabilitation of war-wounded amputees.

Revealing the neural fingerprints of a missing hand.

PubMed

Kikkert, Sanne; Kolasinski, James; Jbabdi, Saad; Tracey, Irene; Beckmann, Christian F; Johansen-Berg, Heidi; Makin, Tamar R

2016-08-23

The hand area of the primary somatosensory cortex contains detailed finger topography, thought to be shaped and maintained by daily life experience. Here we utilise phantom sensations and ultra high-field neuroimaging to uncover preserved, though latent, representation of amputees' missing hand. We show that representation of the missing hand's individual fingers persists in the primary somatosensory cortex even decades after arm amputation. By demonstrating stable topography despite amputation, our finding questions the extent to which continued sensory input is necessary to maintain organisation in sensory cortex, thereby reopening the question what happens to a cortical territory once its main input is lost. The discovery of persistent digit topography of amputees' missing hand could be exploited for the development of intuitive and fine-grained control of neuroprosthetics, requiring neural signals of individual digits.

Enantioselective Effects of Chiral Pesticides on their Primary Targets and Secondary Targets.

PubMed

Yang, Ye; Zhang, Jianyun; Yao, Yijun

2017-01-01

Enantioselectivity has been well recognized in the environmental fate and effects of chiral pesticides. Enantiospecific action of the optical enantiomers on the biological molecules establishes the mechanistic basis for the enantioselective toxicity of chiral pesticides to both target and non-target organisms. We undertook a structured search of bibliographic databases for research literature concerning the enantioselective effects of chiral pesticides, including insecticides, herbicides and fungicides, on biomolecules in various species by using some key words. The results of the relevant literatures were reviewed in the text and summarized in tables. Pesticides generally exert their activity on the target organisms via disrupting the primary target biomolecules. In non-target species, effects of pesticides on the secondary targets distinguished from the primary ones make great contribution to their toxicity. Recent investigations have provided convincing evidence of enantioselective toxicity of chiral pesticides to both target and non-target species which is recognized to result from their enantiospecific action on the primary or secondary targets in organisms. This review confirms that chiral pesticides have enantiospecific effects on both primary and secondary target biomolecules in organisms. Future studies regarding toxicological effects of chiral pesticides should focus on the relationship between the enantiomeric difference in the compound-biomolecules interaction and the enantioselectivity in their toxicity.

Eye tracking a self-moved target with complex hand-target dynamics

PubMed Central

Landelle, Caroline; Montagnini, Anna; Madelain, Laurent

2016-01-01

Previous work has shown that the ability to track with the eye a moving target is substantially improved when the target is self-moved by the subject's hand compared with when being externally moved. Here, we explored a situation in which the mapping between hand movement and target motion was perturbed by simulating an elastic relationship between the hand and target. Our objective was to determine whether the predictive mechanisms driving eye-hand coordination could be updated to accommodate this complex hand-target dynamics. To fully appreciate the behavioral effects of this perturbation, we compared eye tracking performance when self-moving a target with a rigid mapping (simple) and a spring mapping as well as when the subject tracked target trajectories that he/she had previously generated when using the rigid or spring mapping. Concerning the rigid mapping, our results confirmed that smooth pursuit was more accurate when the target was self-moved than externally moved. In contrast, with the spring mapping, eye tracking had initially similar low spatial accuracy (though shorter temporal lag) in the self versus externally moved conditions. However, within ∼5 min of practice, smooth pursuit improved in the self-moved spring condition, up to a level similar to the self-moved rigid condition. Subsequently, when the mapping unexpectedly switched from spring to rigid, the eye initially followed the expected target trajectory and not the real one, thereby suggesting that subjects used an internal representation of the new hand-target dynamics. Overall, these results emphasize the stunning adaptability of smooth pursuit when self-maneuvering objects with complex dynamics. PMID:27466129

Sputter target

DOEpatents

Gates, Willard G.; Hale, Gerald J.

1980-01-01

The disclosure relates to an improved sputter target for use in the deposition of hard coatings. An exemplary target is given wherein titanium diboride is brazed to a tantalum backing plate using a gold-palladium-nickel braze alloy.

Negotiating targets with patients: choice of target in relation to occupational state.

PubMed

Robinson, Sandra M; Walker, David J

2012-02-01

Following the recent National Institute for Health and Clinical Excellence guidance on the management of RA, we were interested to see if we could negotiate targets for treatment with patients in routine clinics, how they would express this and whether staying at work would be a target. One hundred RA patients were recruited. They were consecutive within clinics, but not all clinics were used. They were asked their understanding of the DAS score and a target for treatment negotiated. Any impact of the RA on their paid employment was then explored. Four participants were unable to specify a target for their RA. Negotiated targets were expressed as restricted activities and either as maintaining an activity (70) if the disease was stable, or regaining an activity (26) if the treatment was being increased. Targets were walking a distance for 50% of patients; leisure activities for 18%; domestic activities for 17%; work for 14% and personal care for 2%. For the 21 participants currently working, maintaining work was the target for 12, with 1 wishing to regain lost hours. No patient currently not working expressed returning to work as a target. There were some differences in targets between men and women. Patients are able to negotiate a target for their treatment, expressed as maintaining or regaining a physical activity. Work ceases to be a target once it is lost. Therefore, preventing loss of occupation is likely to be more effective than trying to regain it.

Targeted Nanomaterials for Phototherapy

PubMed Central

Chitgupi, Upendra; Qin, Yiru; Lovell, Jonathan F.

2017-01-01

Phototherapies involve the irradiation of target tissues with light. To further enhance selectivity and potency, numerous molecularly targeted photosensitizers and photoactive nanoparticles have been developed. Active targeting typically involves harnessing the affinity between a ligand and a cell surface receptor for improved accumulation in the targeted tissue. Targeting ligands including peptides, proteins, aptamers and small molecules have been explored for phototherapy. In this review, recent examples of targeted nanomaterials used in phototherapy are summarized. PMID:29071178

Polarized Solid State Target

NASA Astrophysics Data System (ADS)

Dutz, Hartmut; Goertz, Stefan; Meyer, Werner

2017-01-01

The polarized solid state target is an indispensable experimental tool to study single and double polarization observables at low intensity particle beams like tagged photons. It was one of the major components of the Crystal-Barrel experiment at ELSA. Besides the operation of the 'CB frozen spin target' within the experimental program of the Crystal-Barrel collaboration both collaborative groups of the D1 project, the polarized target group of the Ruhr Universität Bochum and the Bonn polarized target group, have made significant developments in the field of polarized targets within the CRC16. The Bonn polarized target group has focused its work on the development of technically challenging polarized solid target systems towards the so called '4π continuous mode polarized target' to operate them in combination with 4π-particle detection systems. In parallel, the Bochum group has developed various highly polarized deuterated target materials and high precision NMR-systems, in the meantime used for polarization experiments at CERN, JLAB and MAMI, too.

Post-targeting strategy for ready-to-use targeted nanodelivery post cargo loading.

PubMed

Zhu, J Y; Hu, J J; Zhang, M K; Yu, W Y; Zheng, D W; Wang, X Q; Feng, J; Zhang, X Z

2017-12-14

Based on boronate formation, this study reports a post-targeting methodology capable of readily installing versatile targeting modules onto a cargo-loaded nanoplatform in aqueous mediums. This permits the targeted nanodelivery of broad-spectrum therapeutics (drug/gene) in a ready-to-use manner while overcoming the PEGylation-dilemma that frequently occurs in conventional targeting approaches.

Magnetically attached sputter targets

DOEpatents

Makowiecki, Daniel M.; McKernan, Mark A.

1994-01-01

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly.

Glioma targeting and blood-brain barrier penetration by dual-targeting doxorubincin liposomes.

PubMed

Gao, Jian-Qing; Lv, Qing; Li, Li-Ming; Tang, Xin-Jiang; Li, Fan-Zhu; Hu, Yu-Lan; Han, Min

2013-07-01

Effective chemotherapy for glioblastoma requires a carrier that can penetrate the blood-brain barrier (BBB) and subsequently target the glioma cells. Dual-targeting doxorubincin (Dox) liposomes were produced by conjugating liposomes with both folate (F) and transferrin (Tf), which were proven effective in penetrating the BBB and targeting tumors, respectively. The liposome was characterized by particle size, Dox entrapment efficiency, and in vitro release profile. Drug accumulation in cells, P-glycoprotein (P-gp) expression, and drug transport across the BBB in the dual-targeting liposome group were examined by using bEnd3 BBB models. In vivo studies demonstrated that the dual-targeting Dox liposomes could transport across the BBB and mainly distribute in the brain glioma. The anti-tumor effect of the dual-targeting liposome was also demonstrated by the increased survival time, decreased tumor volume, and results of both hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling analysis. The dual-targeting Dox liposome could improve the therapeutic efficacy of brain glioma and were less toxic than the Dox solution, showing a dual-targeting effect. These results indicate that this dual-targeting liposome can be used as a potential carrier for glioma chemotherapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Polarized internal target apparatus

DOEpatents

Holt, Roy J.

1986-01-01

A polarized internal target apparatus with a polarized gas target of improved polarization and density achieved by mixing target gas atoms with a small amount of alkali metal gas atoms, and passing a high intensity polarized light source into the mixture to cause the alkali metal gas atoms to become polarized which interact in spin exchange collisions with target gas atoms yielding polarized target gas atoms.

Targeting an efficient target-to-target interval for P300 speller brain–computer interfaces

PubMed Central

Sellers, Eric W.; Wang, Xingyu

2013-01-01

Longer target-to-target intervals (TTI) produce greater P300 event-related potential amplitude, which can increase brain–computer interface (BCI) classification accuracy and decrease the number of flashes needed for accurate character classification. However, longer TTIs requires more time for each trial, which will decrease the information transfer rate of BCI. In this paper, a P300 BCI using a 7 × 12 matrix explored new flash patterns (16-, 18- and 21-flash pattern) with different TTIs to assess the effects of TTI on P300 BCI performance. The new flash patterns were designed to minimize TTI, decrease repetition blindness, and examine the temporal relationship between each flash of a given stimulus by placing a minimum of one (16-flash pattern), two (18-flash pattern), or three (21-flash pattern) non-target flashes between each target flashes. Online results showed that the 16-flash pattern yielded the lowest classification accuracy among the three patterns. The results also showed that the 18-flash pattern provides a significantly higher information transfer rate (ITR) than the 21-flash pattern; both patterns provide high ITR and high accuracy for all subjects. PMID:22350331

Polarized internal target apparatus

DOEpatents

Holt, R.J.

1984-10-10

A polarized internal target apparatus with a polarized gas target of improved polarization and density (achieved by mixing target gas atoms with a small amount of alkali metal gas atoms, and passing a high intensity polarized light source into the mixture to cause the alkali metal gas atoms to become polarized which interact in spin exchange collisions with target gas atoms yielding polarized target gas atoms) is described.

Integrin Targeted MR Imaging

PubMed Central

Tan, Mingqian; Lu, Zheng-Rong

2011-01-01

Magnetic resonance imaging (MRI) is a powerful medical diagnostic imaging modality for integrin targeted imaging, which uses the magnetic resonance of tissue water protons to display tissue anatomic structures with high spatial resolution. Contrast agents are often used in MRI to highlight specific regions of the body and make them easier to visualize. There are four main classes of MRI contrast agents based on their different contrast mechanisms, including T1, T2, chemical exchange saturation transfer (CEST) agents, and heteronuclear contrast agents. Integrins are an important family of heterodimeric transmembrane glycoproteins that function as mediators of cell-cell and cell-extracellular matrix interactions. The overexpressed integrins can be used as the molecular targets for designing suitable integrin targeted contrast agents for MR molecular imaging. Integrin targeted contrast agent includes a targeting agent specific to a target integrin, a paramagnetic agent and a linker connecting the targeting agent with the paramagnetic agent. Proper selection of targeting agents is critical for targeted MRI contrast agents to effectively bind to integrins for in vivo imaging. An ideal integrin targeted MR contrast agent should be non-toxic, provide strong contrast enhancement at the target sites and can be completely excreted from the body after MR imaging. An overview of integrin targeted MR contrast agents based on small molecular and macromolecular Gd(III) complexes, lipid nanoparticles and superparamagnetic nanoparticles is provided for MR molecular imaging. By using proper delivery systems for loading sufficient Gd(III) chelates or superparamagnetic nanoparticles, effective molecular imaging of integrins with MRI has been demonstrated in animal models. PMID:21547154

Magnetically attached sputter targets

DOEpatents

Makowiecki, D.M.; McKernan, M.A.

1994-02-15

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

Genomic Target Database (GTD): A database of potential targets in human pathogenic bacteria

PubMed Central

Barh, Debmalya; Kumar, Anil; Misra, Amarendra Narayana

2009-01-01

A Genomic Target Database (GTD) has been developed having putative genomic drug targets for human bacterial pathogens. The selected pathogens are either drug resistant or vaccines are yet to be developed against them. The drug targets have been identified using subtractive genomics approaches and these are subsequently classified into Drug targets in pathogen specific unique metabolic pathways,Drug targets in host-pathogen common metabolic pathways, andMembrane localized drug targets. HTML code is used to link each target to its various properties and other available public resources. Essential resources and tools for subtractive genomic analysis, sub-cellular localization, vaccine and drug designing are also mentioned. To the best of authors knowledge, no such database (DB) is presently available that has listed metabolic pathways and membrane specific genomic drug targets based on subtractive genomics. Listed targets in GTD are readily available resource in developing drug and vaccine against the respective pathogen, its subtypes, and other family members. Currently GTD contains 58 drug targets for four pathogens. Shortly, drug targets for six more pathogens will be listed. Availability GTD is available at IIOAB website http://www.iioab.webs.com/GTD.htm. It can also be accessed at http://www.iioabdgd.webs.com.GTD is free for academic research and non-commercial use only. Commercial use is strictly prohibited without prior permission from IIOAB. PMID:20011153

Pilots' Attention Distributions Between Chasing a Moving Target and a Stationary Target.

PubMed

Li, Wen-Chin; Yu, Chung-San; Braithwaite, Graham; Greaves, Matthew

2016-12-01

Attention plays a central role in cognitive processing; ineffective attention may induce accidents in flight operations. The objective of the current research was to examine military pilots' attention distributions between chasing a moving target and a stationary target. In the current research, 37 mission-ready F-16 pilots participated. Subjects' eye movements were collected by a portable head-mounted eye-tracker during tactical training in a flight simulator. The scenarios of chasing a moving target (air-to-air) and a stationary target (air-to-surface) consist of three operational phases: searching, aiming, and lock-on to the targets. The findings demonstrated significant differences in pilots' percentage of fixation during the searching phase between air-to-air (M = 37.57, SD = 5.72) and air-to-surface (M = 33.54, SD = 4.68). Fixation duration can indicate pilots' sustained attention to the trajectory of a dynamic target during air combat maneuvers. Aiming at the stationary target resulted in larger pupil size (M = 27,105, SD = 6565), reflecting higher cognitive loading than aiming at the dynamic target (M = 23,864, SD = 8762). Pilots' visual behavior is not only closely related to attention distribution, but also significantly associated with task characteristics. Military pilots demonstrated various visual scan patterns for searching and aiming at different types of targets based on the research settings of a flight simulator. The findings will facilitate system designers' understanding of military pilots' cognitive processes during tactical operations. They will assist human-centered interface design to improve pilots' situational awareness. The application of an eye-tracking device integrated with a flight simulator is a feasible and cost-effective intervention to improve the efficiency and safety of tactical training.Li W-C, Yu C-S, Braithwaite G, Greaves M. Pilots' attention distributions between chasing a moving target and a stationary target. Aerosp Med

TargetSpy: a supervised machine learning approach for microRNA target prediction.

PubMed

Sturm, Martin; Hackenberg, Michael; Langenberger, David; Frishman, Dmitrij

2010-05-28

Virtually all currently available microRNA target site prediction algorithms require the presence of a (conserved) seed match to the 5' end of the microRNA. Recently however, it has been shown that this requirement might be too stringent, leading to a substantial number of missed target sites. We developed TargetSpy, a novel computational approach for predicting target sites regardless of the presence of a seed match. It is based on machine learning and automatic feature selection using a wide spectrum of compositional, structural, and base pairing features covering current biological knowledge. Our model does not rely on evolutionary conservation, which allows the detection of species-specific interactions and makes TargetSpy suitable for analyzing unconserved genomic sequences.In order to allow for an unbiased comparison of TargetSpy to other methods, we classified all algorithms into three groups: I) no seed match requirement, II) seed match requirement, and III) conserved seed match requirement. TargetSpy predictions for classes II and III are generated by appropriate postfiltering. On a human dataset revealing fold-change in protein production for five selected microRNAs our method shows superior performance in all classes. In Drosophila melanogaster not only our class II and III predictions are on par with other algorithms, but notably the class I (no-seed) predictions are just marginally less accurate. We estimate that TargetSpy predicts between 26 and 112 functional target sites without a seed match per microRNA that are missed by all other currently available algorithms. Only a few algorithms can predict target sites without demanding a seed match and TargetSpy demonstrates a substantial improvement in prediction accuracy in that class. Furthermore, when conservation and the presence of a seed match are required, the performance is comparable with state-of-the-art algorithms. TargetSpy was trained on mouse and performs well in human and drosophila

TargetSpy: a supervised machine learning approach for microRNA target prediction

PubMed Central

2010-01-01

Background Virtually all currently available microRNA target site prediction algorithms require the presence of a (conserved) seed match to the 5' end of the microRNA. Recently however, it has been shown that this requirement might be too stringent, leading to a substantial number of missed target sites. Results We developed TargetSpy, a novel computational approach for predicting target sites regardless of the presence of a seed match. It is based on machine learning and automatic feature selection using a wide spectrum of compositional, structural, and base pairing features covering current biological knowledge. Our model does not rely on evolutionary conservation, which allows the detection of species-specific interactions and makes TargetSpy suitable for analyzing unconserved genomic sequences. In order to allow for an unbiased comparison of TargetSpy to other methods, we classified all algorithms into three groups: I) no seed match requirement, II) seed match requirement, and III) conserved seed match requirement. TargetSpy predictions for classes II and III are generated by appropriate postfiltering. On a human dataset revealing fold-change in protein production for five selected microRNAs our method shows superior performance in all classes. In Drosophila melanogaster not only our class II and III predictions are on par with other algorithms, but notably the class I (no-seed) predictions are just marginally less accurate. We estimate that TargetSpy predicts between 26 and 112 functional target sites without a seed match per microRNA that are missed by all other currently available algorithms. Conclusion Only a few algorithms can predict target sites without demanding a seed match and TargetSpy demonstrates a substantial improvement in prediction accuracy in that class. Furthermore, when conservation and the presence of a seed match are required, the performance is comparable with state-of-the-art algorithms. TargetSpy was trained on mouse and performs well

Human target acquisition performance

NASA Astrophysics Data System (ADS)

Teaney, Brian P.; Du Bosq, Todd W.; Reynolds, Joseph P.; Thompson, Roger; Aghera, Sameer; Moyer, Steven K.; Flug, Eric; Espinola, Richard; Hixson, Jonathan

2012-06-01

The battlefield has shifted from armored vehicles to armed insurgents. Target acquisition (identification, recognition, and detection) range performance involving humans as targets is vital for modern warfare. The acquisition and neutralization of armed insurgents while at the same time minimizing fratricide and civilian casualties is a mounting concern. U.S. Army RDECOM CERDEC NVESD has conducted many experiments involving human targets for infrared and reflective band sensors. The target sets include human activities, hand-held objects, uniforms & armament, and other tactically relevant targets. This paper will define a set of standard task difficulty values for identification and recognition associated with human target acquisition performance.

Patient-specific interface pressure case study at transradial prosthetic socket: comparison trials between ICRC polypropylene socket and air splint socket.

PubMed

Abd Razak, Nasrul A; Abu Osman, Noor A; Ali, Sadeeq A; Gholizadeh, Hossein

2016-01-15

While considering how important the interface between the amputees with the prostheses socket, we have carried out research to compare the gradient pressure occur at the interface socket that may lead to the discomforting effects to the user using common ICRC polypropylene socket and air splint socket. Not Applicable SETTING: Not Applicable POPULATION: The subject was a 23 year old who suffered a traumatic defect on the right arm caused by higher electrical volt. F-Socket sensors have been used to measure dynamic socket interface pressure for the transradial amputee wearer during static and dynamic movements. The printed circuit with a thickness of 0.18 mm is equipped between the socket and the surface of the residual limb. Two F-Socket sensor is required to cover the entire socket surface attached to the residual limb. The average of 10 trials made on prosthetic user using both type of sockets for static and dynamic movements was recorded. The pressure gradient shows that the circumference of the socket interface for the ICRC polypropylene socket gives the most pressure distributions to the amputees compared to the pressure gradient for the air splint socket. The pressure gradient for ICRC socket increased consistently when the user makes movements while for the air splint socket remain constantly. The specific interface pressure occur at the socket interface help in determine the comfort and pain of the socket design and improve the correlation between the user and the prosthesis.

Case study: survey of patient satisfaction with prosthesis quality and design among below-knee prosthetic leg socket users.

PubMed

Mohd Hawari, Nurhanisah; Jawaid, Mohammad; Md Tahir, Paridah; Azmeer, Raja Ahmad

2017-11-01

The aim of this case study was to explore patient satisfaction with the quality of prosthetic leg sockets intended for persons with lower limb amputations. A qualitative study based on in-depth interviews, preceded by a questionnaire session, was carried out with patients from the Rehabilitation Center and Hospital in Malaysia. Twelve out-patient and in-patient amputees with lower limb amputations, specifically below-knee amputations, were chosen randomly. The analysis of patients' narratives aimed to identify the functional and esthetic characteristics of currently used prosthetic leg sockets and any problems related to them. The obtained results indicated that out of the 12 participants, 41.7% and 25% were satisfied and somewhat satisfied with their current prosthetic sockets. Durability and comfort were rated by the participants as the most important characteristics of prosthetic sockets, with 83.3%. As regards the esthetic appearance of the socket, 66.7% of the respondents considered that the most important feature was the material from which the socket was fabricated. Thus, we conclude that current satisfaction levels with the quality of prosthetic sockets among amputees in Malaysia are suitable, prosthesis being preferred by many amputees. The results can be used to direct future research on cosmesis and functionality of prosthetic socket design. Implications for Rehabilitation Case study will help participants to get cost effective prosthetic leg socket. Develop prosthetic leg socket comfortable as comparative to existing one. Help Malaysian government to make policy to develop local prosthetic leg socket at affordable price.

Evaluation of transradial body-powered prostheses using a robotic simulator.

PubMed

Ayub, Rafi; Villarreal, Dario; Gregg, Robert D; Gao, Fan

2017-04-01

Transradial body-powered prostheses are extensively used by upper-limb amputees. This prosthesis requires large muscle forces and great concentration by the patient, often leading to discomfort, muscle fatigue, and skin breakdown, limiting the capacity of the amputee to conduct daily activities. Since body-powered prostheses are commonplace, understanding their optimal operation to mitigate these drawbacks would be clinically meaningful. To find the optimal operation of the prosthesis where the activation force is minimized and the grip force is maximized. Experimental design. A computer-controlled robotic amputee simulator capable of rapidly testing multiple elbow, shoulder, and scapular combinations of the residual human arm was constructed. It was fitted with a transradial prosthesis and used to systematically test multiple configurations. We found that increased shoulder flexion, scapular abduction, elbow extension, and the placement of the ring harness near the vertebra C7 correlate with higher gripper operation efficiency, defined as the ratio of grip force to cable tension. We conclude that force transmission efficiency is closely related to body posture configuration. These results could help guide practitioners in clinical practice as well as motivate future studies in optimizing the operation of a body-powered prosthesis. Clinical relevance The results from this study suggest that clinicians ought to place the ring harness inferior and to the sound side of the vertebra prominens in order to maximize grip efficiency. The results will also help clinicians better instruct patients in body posture during prosthesis operation to minimize strain.

Sport Opportunities for Athletes with Disabilities.

ERIC Educational Resources Information Center

Journal of Physical Education, Recreation & Dance, 1984

1984-01-01

This series outlines sport opportunities for athletes with disabilities. Included are articles discussing sports for athletes with cerebral palsy, deaf athletes, blind athletes, wheelchair bound athletes, amputee athletes, as well as a discussion of the Special Olympics. (JMK)

Functional recordings from awake, behaving rodents through a microchannel based regenerative neural interface

NASA Astrophysics Data System (ADS)

Gore, Russell K.; Choi, Yoonsu; Bellamkonda, Ravi; English, Arthur

2015-02-01

Objective. Neural interface technologies could provide controlling connections between the nervous system and external technologies, such as limb prosthetics. The recording of efferent, motor potentials is a critical requirement for a peripheral neural interface, as these signals represent the user-generated neural output intended to drive external devices. Our objective was to evaluate structural and functional neural regeneration through a microchannel neural interface and to characterize potentials recorded from electrodes placed within the microchannels in awake and behaving animals. Approach. Female rats were implanted with muscle EMG electrodes and, following unilateral sciatic nerve transection, the cut nerve was repaired either across a microchannel neural interface or with end-to-end surgical repair. During a 13 week recovery period, direct muscle responses to nerve stimulation proximal to the transection were monitored weekly. In two rats repaired with the neural interface, four wire electrodes were embedded in the microchannels and recordings were obtained within microchannels during proximal stimulation experiments and treadmill locomotion. Main results. In these proof-of-principle experiments, we found that axons from cut nerves were capable of functional reinnervation of distal muscle targets, whether regenerating through a microchannel device or after direct end-to-end repair. Discrete stimulation-evoked and volitional potentials were recorded within interface microchannels in a small group of awake and behaving animals and their firing patterns correlated directly with intramuscular recordings during locomotion. Of 38 potentials extracted, 19 were identified as motor axons reinnervating tibialis anterior or soleus muscles using spike triggered averaging. Significance. These results are evidence for motor axon regeneration through microchannels and are the first report of in vivo recordings from regenerated motor axons within microchannels in a small

Target-directed catalytic metallodrugs

PubMed Central

Joyner, J.C.; Cowan, J.A.

2013-01-01

Most drugs function by binding reversibly to specific biological targets, and therapeutic effects generally require saturation of these targets. One means of decreasing required drug concentrations is incorporation of reactive metal centers that elicit irreversible modification of targets. A common approach has been the design of artificial proteases/nucleases containing metal centers capable of hydrolyzing targeted proteins or nucleic acids. However, these hydrolytic catalysts typically provide relatively low rate constants for target inactivation. Recently, various catalysts were synthesized that use oxidative mechanisms to selectively cleave/inactivate therapeutic targets, including HIV RRE RNA or angiotensin converting enzyme (ACE). These oxidative mechanisms, which typically involve reactive oxygen species (ROS), provide access to comparatively high rate constants for target inactivation. Target-binding affinity, co-reactant selectivity, reduction potential, coordination unsaturation, ROS products (metal-associated vs metal-dissociated; hydroxyl vs superoxide), and multiple-turnover redox chemistry were studied for each catalyst, and these parameters were related to the efficiency, selectivity, and mechanism(s) of inactivation/cleavage of the corresponding target for each catalyst. Important factors for future oxidative catalyst development are 1) positioning of catalyst reduction potential and redox reactivity to match the physiological environment of use, 2) maintenance of catalyst stability by use of chelates with either high denticity or other means of stabilization, such as the square planar geometric stabilization of Ni- and Cu-ATCUN complexes, 3) optimal rate of inactivation of targets relative to the rate of generation of diffusible ROS, 4) targeting and linker domains that afford better control of catalyst orientation, and 5) general bio-availability and drug delivery requirements. PMID:23828584

Target attribute-based false alarm rejection in small infrared target detection

NASA Astrophysics Data System (ADS)

Kim, Sungho

2012-11-01

Infrared search and track is an important research area in military applications. Although there are a lot of works on small infrared target detection methods, we cannot apply them in real field due to high false alarm rate caused by clutters. This paper presents a novel target attribute extraction and machine learning-based target discrimination method. Eight kinds of target features are extracted and analyzed statistically. Learning-based classifiers such as SVM and Adaboost are developed and compared with conventional classifiers for real infrared images. In addition, the generalization capability is also inspected for various infrared clutters.

Nuclear Security: Target Analysis

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

Singh, Surinder Paul; Gibbs, Philip W.; Bultz, Garl A.

2014-03-01

This objectives of this session were to understand the basic steps of target identification; describe the SNRI targets in detail; characterize specific targets with more detail; prioritize targets based on guidance documents; understand the graded safeguards concept; identify roll up and understand why it is a concern; and recognize the category for different materials.

Rehand: Realistic electric prosthetic hand created with a 3D printer.

PubMed

Yoshikawa, Masahiro; Sato, Ryo; Higashihara, Takanori; Ogasawara, Tsukasa; Kawashima, Noritaka

2015-01-01

Myoelectric prosthetic hands provide an appearance with five fingers and a grasping function to forearm amputees. However, they have problems in weight, appearance, and cost. This paper reports on the Rehand, a realistic electric prosthetic hand created with a 3D printer. It provides a realistic appearance that is same as the cosmetic prosthetic hand and a grasping function. A simple link mechanism with one linear actuator for grasping and 3D printed parts achieve low cost, light weight, and ease of maintenance. An operating system based on a distance sensor provides a natural operability equivalent to the myoelectric control system. A supporter socket allows them to wear the prosthetic hand easily. An evaluation using the Southampton Hand Assessment Procedure (SHAP) demonstrated that an amputee was able to operate various objects and do everyday activities with the Rehand.