Chronic Exertional Compartment Syndrome Requiring Bilateral Fasciotomy: An Atypical Complication of Familial Stiff Skin Syndrome in a Father and Son.

ABSTRACT: Stiff skin syndrome (SSS) is a rare cutaneous disorder characterized by cutaneous fibrosis resulting in the early onset of thickened and indurated skin, joint mobility restrictions, and contractures. We describe a father and son with familial SSS who presented with bilateral exertional pain and a confirmed diagnosis of chronic exertional compartment syndrome on 4-compartment pressure testing. Patients experienced restored functionality with bilateral 4-compartment fasciotomy. Chronic exertional compartment syndrome should be considered in the differential diagnosis of patients with SSS and chronic pain of the lower limbs.

Upper limb prostheses: bridging the sensory gap.

Replacing human hand function with prostheses goes far beyond only recreating muscle movement with feedforward motor control. Natural sensory feedback is pivotal for fine dexterous control and finding both engineering and surgical solutions to replace this complex biological function is imperative to achieve prosthetic hand function that matches the human hand. This review outlines the nature of the problems underlying sensory restitution, the engineering methods that attempt to address this deficit and the surgical techniques that have been developed to integrate advanced neural interfaces with biological systems. Currently, there is no single solution to restore sensory feedback. Rather, encouraging animal models and early human studies have demonstrated that some elements of sensation can be restored to improve prosthetic control. However, these techniques are limited to highly specialized institutions and much further work is required to reproduce the results achieved, with the goal of increasing availability of advanced closed loop prostheses that allow sensory feedback to inform more precise feedforward control movements and increase functionality.

Biomechanical Analysis of Body Movements of Myoelectric Prosthesis Users During Standardized Clinical Tests.

OBJECTIVE: The objective clinical evaluation of user's capabilities to handle their prosthesis is done using various tests which primarily focus on the task completion speed and do not explicitly account for the potential presence of compensatory motions. Given that the excessive body compensation is a common indicator of inadequate prosthesis control, tests which include subjective observations on the quality of performed motions have been introduced. However, these metrics are then influenced by the examiner's opinions, skills, and training making them harder to standardize across patient pools and compare across different prosthetic technologies. Here we aim to objectively quantify the severity of body compensations present in myoelectric prosthetic hand users and evaluate the extent to which traditional objective clinical scores are still able to capture them. METHODS: We have instructed 9 below-elbow prosthesis users and 9 able-bodied participants to complete three established objective clinical tests: Box-and-Blocks-Test, Clothespin-Relocation-Test, and Southampton-Hand-Assessment-Procedure. During all tests, upper-body kinematics has been recorded. RESULTS: While the analysis showed that there are some correlations between the achieved clinical scores and the individual body segment travel distances and average speeds, there were only weak correlations between the clinical scores and the observed ranges of motion. At the same time, the compensations were observed in all prosthesis users and, for the most part, they were substantial across the tests. CONCLUSION: The sole reliance on the currently available objective clinical assessment methods seems inadequate as the compensatory movements are prominent in prosthesis users and yet not sufficiently accounted for.

A Haptic Sleeve as a Method of Mechanotactile Feedback Restoration for Myoelectric Hand Prosthesis Users.

Current myoelectric upper limb prostheses do not restore sensory feedback, impairing fine motor control. Mechanotactile feedback restoration with a haptic sleeve may rectify this problem. This randomised crossover within-participant controlled study aimed to assess a prototype haptic sleeve's effect on routine grasping tasks performed by eight able-bodied participants. Each participant completed 15 repetitions of the three tasks: Task 1-normal grasp, Task 2-strong grasp and Task 3-weak grasp, using visual, haptic, or combined feedback All data were collected in April 2021 in the Scottish Microelectronics Centre, Edinburgh, UK. Combined feedback correlated with significantly higher grasp success rates compared to the vision alone in Task 1 (p < 0.0001), Task 2 (p = 0.0057), and Task 3 (p = 0.0170). Similarly, haptic feedback was associated with significantly higher grasp success rates compared to vision in Task 1 (p < 0.0001) and Task 2 (p = 0.0015). Combined feedback correlated with significantly lower energy expenditure compared to visual feedback in Task 1 (p < 0.0001) and Task 3 (p = 0.0003). Likewise, haptic feedback was associated with significantly lower energy expenditure compared to the visual feedback in Task 1 (p < 0.0001), Task 2 (p < 0.0001), and Task 3 (p < 0.0001). These results suggest that mechanotactile feedback provided by the haptic sleeve effectively augments grasping and reduces its energy expenditure.

Personalised 3D printed respirators for healthcare workers during the COVID-19 pandemic.

Widespread issues in respirator availability and fit have been rendered acutely apparent by the COVID-19 pandemic. This study sought to determine whether personalized 3D printed respirators provide adequate filtration and function for healthcare workers through a Randomized Controlled Trial (RCT). Fifty healthcare workers recruited within NHS Lothian, Scotland, underwent 3D facial scanning or 3D photographic reconstruction to produce 3D printed personalized respirators. The primary outcome measure was quantitative fit-testing to FFP3 standard. Secondary measures included respirator comfort, wearing experience, and function instrument (R-COMFI) for tolerability, Modified Rhyme Test (MRT) for intelligibility, and viral decontamination on respirator material. Of the 50 participants, 44 passed the fit test with the customized respirator, not significantly different from the 38 with the control (p = 0.21). The customized respirator had significantly improved comfort over the control respirator in both simulated clinical conditions (p < 0.0001) and during longer wear (p < 0.0001). For speech intelligibility, both respirators performed equally. Standard NHS decontamination agents were able to eradicate 99.9% of viral infectivity from the 3D printed plastics tested. Personalized 3D printed respirators performed to the same level as control disposable FFP3 respirators, with clear communication and with increased comfort, wearing experience, and function. The materials used were easily decontaminated of viral infectivity and would be applicable for sustainable and reusable respirators.

Outcomes, Challenges, and Pitfalls after Targeted Muscle Reinnervation in High-Level Amputees: Is It Worth the Effort?

BACKGROUND: Although the distal targets have been lost in proximal upper limb amputees, the neural signals for intuitive hand and arm function are still available and thus can be incorporated into more useful prosthetic function using targeted muscle reinnervation technique. In this article, the authors present their outcomes and range of indications in addition to experiences and pitfalls after 30 targeted muscle reinnervation cases at above-elbow and shoulder disarticulation level of amputation. METHODS: Thirty patients with above-elbow or shoulder disarticulation amputations were enrolled between 2012 and 2017. Indications for targeted muscle reinnervation surgery differed between improvement of prosthetic function (n = 19) and/or pain (n = 11). Functional outcome was evaluated with the Action Research Arm Test, the Southampton Hand Assessment Procedure, and the Clothespin-Relocation Test. Functional evaluation was performed at least at 6 months after final prosthetic fitting. RESULTS: All nerve transfers were successful and provided independent myoelectric signals. The 10 patients available for final functional evaluation showed Action Research Arm Test scores of 20.4 ± 1.9 and Southampton Hand Assessment Procedure scores of 40.5 ± 8.1. The Clothespin-Relocation Test showed a mean time of 34.3 ± 14.4 seconds. CONCLUSIONS: Targeted muscle reinnervation has improved prosthetic control and revolutionized neuroma treatment in upper limb amputees. Still, the rate of abandonment even after targeted muscle reinnervation surgery has been shown high, and several advances within the biotechnological interface will be needed to improve prosthetic function and acceptance in these patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Functional Outcome Scores With Standard Myoelectric Prostheses in Below-Elbow Amputees.

OBJECTIVE: The aim of the study was to report normative outcome data of prosthetic hand function in below-elbow amputees using four different objective measurements closely related to activities of daily living. DESIGN: Seventeen patients who underwent prosthetic fitting after unilateral below-elbow amputation were enrolled in this study. Global upper extremity function was evaluated using the Action Research Arm Test, Southampton Hand Assessment Procedure, the Clothespin-Relocation Test, and the Box and Block Test, which monitor hand and extremity function. RESULTS: The patients achieved a mean ± SD Action Research Arm Test score of 35.06 ± 4.42 of 57. The mean ± SD Southampton Hand Assessment Procedure score was 65.12 ± 13.95 points. The mean ± SD time for the Clothespin-Relocation Test was 22.57 ± 7.50 secs, and the mean ± SD score in the Box and Block Test was 20.90 ± 5.74. CONCLUSIONS: In the current economic situation of health care systems, demonstrating the effectiveness and necessity of rehabilitation interventions is of major importance. This study reports outcome data of below-elbow amputees and provides a useful guide for expected prosthetic user performance.

Attachment of upper arm prostheses with a subcutaneous osseointegrated implant in transhumeral amputees.

BACKGROUND: The stump-socket interface is of utmost importance for prosthetic function in transhumeral amputees. Stability of this connection may be improved using a newly designed subcutaneous implant. OBJECTIVES: The purpose was to determine the effect of the implant together with customized socket designs on the range of motion of the shoulder and the prosthetic function compared to conventional fitting. STUDY DESIGN: Case series. METHODS: The range of motion was measured with scaled metrics and the prosthetic function evaluated with the Southampton Hand Assessment Procedure and the Box and Block Test. Maximal loading was measured in straight and 90° flexion of the elbow. RESULTS: The restriction of range of motion after conventional fitting was decreased from 42.55% ± 6.56% to 9.23% ± 14.89% in Patient I and from 62.18% ± 15.19% to 2.51% ± 2.49% in Patient II using the implant with customized sockets compared to range of motion without prosthesis. Both patients showed improved prosthetic function with the new system compared to conventional fitting. CONCLUSION: The presented subcutaneous humeral implant, together with customized socket designs without straps and harnesses to the contralateral shoulder, can maintain almost complete range of motion of the shoulder. This resulted in improved prosthetic function and comfort for the patient without constant risk of infection. Clinical relevance Discomfort and limited prosthetic function are the main reasons for abandonment especially in transhumeral amputees. Shoulder straps and harnesses within conventional socket designs may not only lead to pain and skin irritations at the contralateral shoulder but also limit the range of motion of the shoulder joint and therefore prosthetic function.

Fascicular shifting: a novel technique to overcome large nerve defects.

OBJECTIVE Over the last decade, a number of authors have investigated the utility of different biological and synthetic matrices as alternatives to conventional nerve grafts. However, the autologous nerve graft remains the gold standard, even though it often involves using a pure sensory nerve to reconstruct a mixed or even a pure motor nerve. Furthermore, limited donor sites often necessitate a significant mismatch of needed nerve tissue, especially for large proximal nerve defects such as brachial plexus lesions. Here, the authors present a new technique that overcomes these problems: the fascicular shift procedure (FSP). A fascicular group of the nerve distal to the injury is harvested in a sufficient length to bridge the nerve defect. METHODS The method of fascicular shifting was tested at the sciatic nerve in 45 Lewis rats. In the experimental group, a 15-mm nerve defect was created and reconstructed with a fascicular group that was harvested directly distal to the gap. This group was compared with 1 negative control group (defect without reconstruction) and 3 positive control groups (sensory, motor, and mixed graft). After 12 weeks of nerve regeneration, outcome was evaluated using retrograde labeling, histomorphometric analysis, and muscle force analysis. RESULTS All reconstructed groups showed successful regeneration with various levels of function. The negative control group showed minimal force measurements that were of no functional value. The fascicular shift provided sufficient guidance to overcome nerve defects, had higher (p < 0.1) motor neuron counts (1958.75 ± 657.21) than the sensory graft (1263.50 ± 538.90), and was equal to motor grafts (1490.43 ± 794.80) and mixed grafts (1720.00 ± 866.421). This tendency of improved motor regeneration was confirmed in all analyses. The mixed graft group was compared with the experimental group to investigate the influence of the potential damage induced by the fascicular shift distal to the repair site. However, none of the analyses revealed an impairment of nerve regeneration for both the tibial and common peroneal index muscles. CONCLUSIONS This study demonstrates that harvesting a transplant from the nerve segment distal to the injury site offers a mixed graft without causing additional donor-site morbidity. These grafts perform statistically better than a standard sensory graft in terms of motor recovery. The fascicular shift presents a novel method to reconstruct large proximal nerve defects, making it immensely attractive in brachial plexus reconstruction.

Axonal components of nerves innervating the human arm.

OBJECTIVE: Axons traveling within the brachial plexus are responsible for the dexterous control of human arm and hand movements. Despite comprehensive knowledge on the topographical anatomy of nerves innervating the human upper limbs, the definite quantity of sensory and motor axons within this neural network remains elusive. Our aim was to perform a quantitative analysis of the axonal components of human upper limb nerves based on highly specific molecular features from spinal cord level to the terminal nerves at wrist level. METHODS: Nerve specimen harvest at predefined harvesting sites (plexus roots and cords as well as major nerves originating from the brachial plexus innervating the arm and hand) was performed in 9 human heart-beating organ donors. Double immunofluorescence staining using antibodies against choline-acetyltransferase and neurofilament was performed to differentiate motor and sensory axons on nerve cross sections. RESULTS: Three hundred fifty thousand axons emerge from the spinal cord to innervate the human upper limb, of which 10% are motor neurons. In all nerves studied, sensory axons outnumber motor axons by a ratio of at least 9:1. The sensory axon contribution increases when moving distally, whereas only 1,700 motor axons reach the hand to innervate the intrinsic musculature. INTERPRETATION: Our results suggest that upper limb motor execution, and particularly dexterous coordination of hand movement, require an unexpectedly low number of motor neurons, with a large convergence of afferent input for feedback control. Ann Neurol 2017;82:396-408.

Translating Research on Myoelectric Control into Clinics-Are the Performance Assessment Methods Adequate?

Missing an upper limb dramatically impairs daily-life activities. Efforts in overcoming the issues arising from this disability have been made in both academia and industry, although their clinical outcome is still limited. Translation of prosthetic research into clinics has been challenging because of the difficulties in meeting the necessary requirements of the market. In this perspective article, we suggest that one relevant factor determining the relatively small clinical impact of myocontrol algorithms for upper limb prostheses is the limit of commonly used laboratory performance metrics. The laboratory conditions, in which the majority of the solutions are being evaluated, fail to sufficiently replicate real-life challenges. We qualitatively support this argument with representative data from seven transradial amputees. Their ability to control a myoelectric prosthesis was tested by measuring the accuracy of offline EMG signal classification, as a typical laboratory performance metrics, as well as by clinical scores when performing standard tests of daily living. Despite all subjects reaching relatively high classification accuracy offline, their clinical scores varied greatly and were not strongly predicted by classification accuracy. We therefore support the suggestion to test myocontrol systems using clinical tests on amputees, fully fitted with sockets and prostheses highly resembling the systems they would use in daily living, as evaluation benchmark. Agreement on this level of testing for systems developed in research laboratories would facilitate clinically relevant progresses in this field.

Elective amputation and bionic substitution restore functional hand use after critical soft tissue injuries.

Critical soft tissue injuries may lead to a non-functional and insensate limb. In these cases standard reconstructive techniques will not suffice to provide a useful outcome, and solutions outside the biological arena must be considered and offered to these patients. We propose a concept which, after all reconstructive options have been exhausted, involves an elective amputation along with a bionic substitution, implementing an actuated prosthetic hand via a structured tech-neuro-rehabilitation program. Here, three patients are presented in whom this concept has been successfully applied after mutilating hand injuries. Clinical tests conducted before, during and after the procedure, evaluating both functional and psychometric parameters, document the benefits of this approach. Additionally, in one of the patients, we show the possibility of implementing a highly functional and natural control of an advanced prosthesis providing both proportional and simultaneous movements of the wrist and hand for completing tasks of daily living with substantially less compensatory movements compared to the traditional systems. It is concluded that the proposed procedure is a viable solution for re-gaining highly functional hand use following critical soft tissue injuries when existing surgical measures fail. Our results are clinically applicable and can be extended to institutions with similar resources.

Functional and Psychosocial Outcomes of Hand Transplantation Compared with Prosthetic Fitting in Below-Elbow Amputees: A Multicenter Cohort Study.

BACKGROUND: Hand-transplantation and improvements in the field of prostheses opened new frontiers in restoring hand function in below-elbow amputees. Both concepts aim at restoring reliable hand function, however, the indications, advantages and limitations for each treatment must be carefully considered depending on level and extent of amputation. Here we report our findings of a multi-center cohort study comparing hand function and quality-of-life of people with transplanted versus prosthetic hands. METHODS: Hand function in amputees with either transplant or prostheses was tested with Action Research Arm Test (ARAT), Southampton Hand Assessment Procedure (SHAP) and the Disabilities of the Arm, Shoulder and Hand measure (DASH). Quality-of-life was compared with the Short-Form 36 (SF-36). RESULTS: Transplanted patients (n = 5) achieved a mean ARAT score of 40.86 ± 8.07 and an average SHAP score of 75.00 ± 11.06. Prosthetic patients (n = 7) achieved a mean ARAT score of 39.00 ± 3.61 and an average SHAP score of 75.43 ± 10.81. There was no significant difference between transplanted and prosthetic hands in ARAT, SHAP or DASH. While quality-of-life metrics were equivocal for four scales of the SF-36, transplanted patients reported significantly higher scores in "role-physical" (p = 0.006), "vitality" (p = 0.008), "role-emotional" (p = 0.035) and "mental-health" (p = 0.003). CONCLUSIONS: The indications for hand transplantation or prosthetic fitting in below-elbow amputees require careful consideration. As functional outcomes were not significantly different between groups, patient's best interests and the route of least harm should guide treatment. Due to the immunosuppressive side-effects, the indication for allotransplantation must still be restrictive, the best being bilateral amputees.

Improving arm function by prosthetic limb replacement in a patient with severe arthrogryposis multiplex congenita.

OBJECTIVE: In patients with severe bilateral congenital arm deficiencies, even simple activities of daily living, such as feeding, may be major challenges. We report here a case of a patient with arthrogryposis multiplex congenita affecting all 4 extremities, who underwent prosthetic replacement after elective transhumeral amputation of his right functionless arm. CASE REPORT: A 22-year-old man with arthrogryposis multiplex congenita had severe deficits of his upper limbs. Previous surgeries for upper and lower limbs had enabled this patient to walk without aids; however, his upper limbs remained severely impaired. After prosthetic rehabilitation, including nerve and muscle transfers, a carefully planned elective amputation, signal processing and a comprehensive rehabilitation programme, the patient was able to independently conduct normal activities of daily living that had hitherto been impossible. The Disabilities of the Arm, Shoulder and Hand measure improved from 73.3 to 44.2, the Action Research Arm Test improved from 10 to 18 out of 57 points and the Southampton Hand Assessment Procedure improved from 8 to 23 after prosthetic replacement. CONCLUSION: Prosthetic replacement can improve upper limb function in patients with severe congenital limb deficiencies. In the case reported here, functional rehabilitation had a positive impact on the patient's quality of life and self-confidence, as he integrated the prosthesis into his body image.

Motor Unit Characteristics after Targeted Muscle Reinnervation.

Targeted muscle reinnervation (TMR) is a surgical procedure used to redirect nerves originally controlling muscles of the amputated limb into remaining muscles above the amputation, to treat phantom limb pain and facilitate prosthetic control. While this procedure effectively establishes robust prosthetic control, there is little knowledge on the behavior and characteristics of the reinnervated motor units. In this study we compared the m. pectoralis of five TMR patients to nine able-bodied controls with respect to motor unit action potential (MUAP) characteristics. We recorded and decomposed high-density surface EMG signals into individual spike trains of motor unit action potentials. In the TMR patients the MUAP surface area normalized to the electrode grid surface (0.25 ± 0.17 and 0.81 ± 0.46, p < 0.001) and the MUAP duration (10.92 ± 3.89 ms and 14.03 ± 3.91 ms, p < 0.01) were smaller for the TMR group than for the controls. The mean MUAP amplitude (0.19 ± 0.11 mV and 0.14 ± 0.06 mV, p = 0.07) was not significantly different between the two groups. Finally, we observed that MUAP surface representation in TMR generally overlapped, and the surface occupied by motor units corresponding to only one motor task was on average smaller than 12% of the electrode surface. These results suggest that smaller MUAP surface areas in TMR patients do not necessarily facilitate prosthetic control due to a high degree of overlap between these areas, and a neural information-based control could lead to improved performance. Based on the results we also infer that the size of the motor units after reinnervation is influenced by the size of the innervating motor neuron.

Context-Dependent Upper Limb Prosthesis Control for Natural and Robust Use.

Pattern recognition and regression methods applied to the surface EMG have been used for estimating the user intended motor tasks across multiple degrees of freedom (DOF), for prosthetic control. While these methods are effective in several conditions, they are still characterized by some shortcomings. In this study we propose a methodology that combines these two approaches for mutually alleviating their limitations. This resulted in a control method capable of context-dependent movement estimation that switched automatically between sequential (one DOF at a time) or simultaneous (multiple DOF) prosthesis control, based on an online estimation of signal dimensionality. The proposed method was evaluated in scenarios close to real-life situations, with the control of a physical prosthesis in applied tasks of varying difficulties. Test prostheses were individually manufactured for both able-bodied and transradial amputee subjects. With these prostheses, two amputees performed the Southampton Hand Assessment Procedure test with scores of 58 and 71 points. The five able-bodied individuals performed standardized tests, such as the box&block and clothes pin test, reducing the completion times by up to 30%, with respect to using a state-of-the-art pure sequential control algorithm. Apart from facilitating fast simultaneous movements, the proposed control scheme was also more intuitive to use, since human movements are predominated by simultaneous activations across joints. The proposed method thus represents a significant step towards intelligent, intuitive and natural control of upper limb prostheses.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

A surface EMG test tool to measure proportional prosthetic control.

In upper limb amputees, prosthetic control training is recommended before and after fitting. During rehabilitation, the focus is on selective proportional control signals. For functional monitoring, many different tests are available. None can be used in the early phase of training. However, an early assessment is needed to judge if a patient has the potential to control a certain prosthetic set-up. This early analysis will determine if further training is needed or if other strategies would be more appropriate. Presented here is a tool that is capable of predicting achievable function in voluntary EMG control. This tool is applicable to individual muscle groups to support preparation of training and fitting. In four of five patients, the sEMG test tool accurately predicted the suitability for further myoelectric training based on SHAP outcome measures. (P1: "Poor" function in the sEMG test tool corresponded to 54/100 in the SHAP test; P2: Good: 85; P3: Good: 81; P4: Average: 78). One patient scored well during sEMG testing, but was unmotivated during SHAP testing. (Good: 50) Therefore, the surface EMG test tool may predict achievable control skills to a high extent, validated with the SHAP, but requires further clinical testing to validate this technique.

Bionic reconstruction to restore hand function after brachial plexus injury: a case series of three patients.

BACKGROUND: Brachial plexus injuries can permanently impair hand function, yet present surgical reconstruction provides only poor results. Here, we present for the first time bionic reconstruction; a combined technique of selective nerve and muscle transfers, elective amputation, and prosthetic rehabilitation to regain hand function. METHODS: Between April 2011, and May 2014, three patients with global brachial plexus injury including lower root avulsions underwent bionic reconstruction. Treatment occurred in two stages; first, to identify and create useful electromyographic signals for prosthetic control, and second, to amputate the hand and replace it with a mechatronic prosthesis. Before amputation, the patients had a specifically tailored rehabilitation programme to enhance electromyographic signals and cognitive control of the prosthesis. Final prosthetic fitting was applied as early as 6 weeks after amputation. FINDINGS: Bionic reconstruction successfully enabled prosthetic hand use in all three patients. After 3 months, mean Action Research Arm Test score increased from 5·3 (SD 4·73) to 30·7 (14·0). Mean Southampton Hand Assessment Procedure score improved from 9·3 (SD 1·5) to 65·3 (SD 19·4). Mean Disabilities of Arm, Shoulder and Hand score improved from 46·5 (SD 18·7) to 11·7 (SD 8·42). INTERPRETATION: For patients with global brachial plexus injury with lower root avulsions, who have no alternative treatment, bionic reconstruction offers a means to restore hand function. FUNDING: Austrian Council for Research and Technology Development, Austrian Federal Ministry of Science, Research & Economy, and European Research Council Advanced Grant DEMOVE.

Multiregion thermal sensitivity mapping of the hand.

Previous neurophysiological studies of discrete hand regions have suggested the dorsum to be more sensitive to temperature changes than the palmar surface, but no multiple-region investigation of the corresponding dorsal and palmar regions has been performed. This study aimed to investigate whether the dorsum of the hand is more sensitive to temperature changes than the palm across multiple regions. In 15 healthy human volunteers, cold and warmth detection thresholds were measured in 10 defined areas of the hand using a thermode of 2.56 cm(2). The testing algorithm employed was the Method of Limits with a baseline temperature of 32 °C and a rate of change of 1°/s. In five subjects, cold-pain and heat-pain thresholds were also measured. All dorsal regions were significantly more sensitive to cold than equivalent palmar areas. Differences in warmth thresholds were not uniform but, overall, dorsal sensitivity was significantly higher. This study finds that the dorsal aspect of the hand was more sensitive to temperature changes than the palm, with higher sensitivity to painful thermal stimuli.