Upper-limb Amputees Research Articles

Evaluation of performance results for low-cost 3D printed myoelectric prosthetic devices during Cybathlon 2020 ARM discipline

The performance of a low-cost 3D printed myoelectric prosthetic device known as the Touch Hand 4.5, at the 2020 Cybathlon competition is discussed. This device is under development as a low-cost prosthetic device for upper-limb amputees. The Touch hand team placed 13th out of 15 teams at the Cybathlon competition. By assessing the performance of the device and comparing with the performance of competitors, avenues of future research for the improvement of the Touch hand are identified.

A CW-CNN regression model-based real-time system for virtual hand control.

For upper limb amputees, wearing a myoelectric prosthetic hand is the only way for them to continue normal life. Even until now, the proposal of a high-precision and natural performance real-time control system based on surface electromyography (sEMG) signals is still challenging. Researchers have proposed many strategies for motion classification or regression prediction tasks based on sEMG signals. However, most of them have been limited to offline analysis only. There are even few papers on real-time control based on deep learning models, almost all of which are about motion classification. Rare studies tried to use deep learning-based regression models in real-time control systems for multi-joint angle estimation via sEMG signals. This paper proposed a CW-CNN regression model-based real-time control system for virtual hand control. We designed an Adaptive Kalman Filter to smooth the joint angles output before sending them as control commands to control a virtual hand. Eight healthy participants were invited, and three sessions experiments were conducted on two different days for all of them. During the real-time experiment, we analyzed the joint angles estimation accuracy and computational latency. Moreover, target achievement control (TAC) test was applied to emphasize motion regression in real-time. The experimental results show that the proposed control system has high precision for 3-DOFs motion regression in simultaneously, and the system remains stable and low computational latency. In the future, the proposed real-time control system can be applied to actual prosthetic hand.

Management of Upper Limb Amputation Rehabilitation: Synopsis of the 2022 US Department of Veterans Affairs and US Department of Defense Clinical Practice Guideline for Acquired Amputation.

Upper limb amputation can result in significant functional impairment necessitating a comprehensive rehabilitation approach throughout the continuum of care. In 2022, the Departments of Veteran Affairs and Defense completed an updated clinical practice guideline for the management of upper limb amputation rehabilitation. This practice guideline was developed by a workgroup of subject-matter experts from a variety of disciplines. Twelve key questions were developed by the workgroup using the PICOTS (population, intervention, comparator, outcomes, timing of outcomes measurement, and setting) format to establish the scope of the literature review. Eighteen recommendations were developed through extensive review of the available literature and use of the Grading of Recommendations, Assessment, Development and Evaluation criteria. The strength of each recommendation was determined based on the quality of the research evidence and the additional domains of the Grading of Recommendations, Assessment, Development and Evaluation criteria. Of the 18 recommendations, 4 were found to have sufficient evidence to suggest for use of a particular rehabilitation management strategy. Thus, the 2022 Department of Veteran Affairs and Department of Defense clinical practice guideline provides updated, evidence-based information on the care and rehabilitation of persons with upper limb amputation. However, a significant lack of high-quality evidence in upper limb amputation rehabilitation limited evidence-based clinical guidance to assist healthcare providers in managing this population.

Targeted Box and Blocks Test: Evidence of Convergent Validity in Upper Limb Prosthesis User Population

<h3>Research Objectives</h3> To conduct an initial psychometric evaluation in the upper limb prosthesis user population of a novel performance-based measure called the targeted Box and Blocks Test (tBBT) requiring controlled grasping, transport, and release of objects that can be used to evaluate upper limb functional ability. <h3>Design</h3> Nonrandomized controlled trial. <h3>Setting</h3> Academic research lab. <h3>Participants</h3> A convenience sample of n = 8 transradial myoelectric prosthesis users (3F/5M; mean age 46.3 ± 14.3 years). Nearly all prosthesis users used their myoelectric prosthetic device >8 hours/day and >5 days/week. Time since amputation for all but two prosthesis users was less than 6 years. <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> Participants were timed as they performed two trials each of the tBBT (in both a standing and seated position); the fork, reach overhead, and door knob tasks from the Activities Measure for Upper Limb Amputees (AM-ULA); and the picture frame, bottle squeeze, and pick up dice tasks from the Capacity Assessment of Prosthesis Performance for the Upper Limb (CAPPFUL). Average time of trials was used to calculate the Pearson correlation coefficients between tBBT and each task performed from the CAPPFUL and AM-ULA. <h3>Results</h3> Nearly all correlations between the tBBT (standing and seated) and select tasks from the AM-ULA and CAPPFUL were moderate to strong, ranging from 0.48 to 0.90. The correlation between tBBT in a seated position and the reach overhead AM-ULA task was weaker (R = 0.38). Interestingly, there was a significant strong negative correlation between tBBT score and the CAPPFUL task of squeezing water from a bottle (R = -0.89 for tBBT standing and R = -.76 for tBBT seated). <h3>Conclusions</h3> Preliminary results demonstrate the tBBT in both seated and standing positions has acceptable convergent validity in the upper limb prosthesis user population. Additional psychometric properties (e.g., known-group validity, test-retest reliability) should be determined to fully characterize this novel measure. <h3>Author(s) Disclosures</h3> None.

Pressure and Angle Sensors with Optical Fiber for Instrumentation of the PrHand Hand Prosthesis

The principal cause of upper limb amputations is due to traumatism. The prosthesis is an assistive device to help in the activities of daily for the amputee person. However, one of the latest reports shows that in developing countries there are around 30 million people without assistive devices. This work presents the development of two kinds of sensors for the PrHand, an upper limb prosthesis based on compliant mechanism and soft-robotics. The sensors are made with polymeric optical fiber (POF), due to their flexibility and low cost, and the working principle is based on intensity variation. The angle sensors are used for monitoring the interphalangeal joint of the fingers, and for the assessment were made cycles of closing and opening each finger. On the other hand, the force sensors are located at the tip of three fingers to track the force made over the objects. Before encoring the sensors were evaluated making five cycles of compressing and decompressing each sensor. The results show a linear behavior between the angle and the voltage variation, one most remarkable angle sensor result was with a sensibility of 0.0357 V/° and an R2 of 99 % closing and 0.0483 V/° opening. In the case of the force sensor, a polynomial relation was found between the voltage changes and the pressure over the sensor; in some cases, the relation between voltage changes and pressure could be linear but that depends on the construction of the sensor. Regarding the obtained R2 of 99 %, its sensibility was 0.0361 V/N compression and 0.0368 V/N decompression. In conclusion, was successfully developed two kinds of sensors for the instrumentation of PrHand prosthesis. It is expected to use angle and sensor variables as input in algorithms of Machine Learning to improve the detection of objects. One aspect to improve is to control in a better way the sensor construction parameters due to the considerable influence over the sensor behavior.

PEComa. About a case.

PEComa (perivascular epithelioid cell) is a rare perivascular mesenchymal cell tumor that can appear anywhere in the body. It is uncommon as a primary bone tumor. Our case is a 28-year-old woman with shoulder pain of two months of evolution who suffered a pathological fracture in the proximal humerus. After imaging tests and biopsy, PE Coma was diagnosed. This tumor has a particular immunohistochemistry (IHC): it presents HMN45 + melanic markers and Actin + and S-100 - muscle markers. Our case is treated with extra-articular amputation of the right upper limb. This seems to be the only case of proximal humerus. It is essential to know the IHC markers because they are very characteristic. The patient had phantom limb symptoms and required psychological help.

SEMG based Real-Time Motion Classification using Virtual Reality and Artificial Neural Networks

The work presented in this paper addresses the enhancement of upper body rehabilitation and training methods for stroke victims and upper body amputees. One of the primary aims is to develop a tool that utilizes augmented reality to facilitate the rehabilitation of impaired human hand and forearm movements by employing mirror neurons and virtual reality. The second objective of the proposed tool is to allow for evaluation and specification of prostheses prior to acquisition and fitting of such devices to upper limb amputees. The proposed system involves the development of real–time surface Electromyography (sEMG) signal classification methods, Artificial Neural Network training, and implementation and the development of identification algorithms for inferring motion intend. The results of the proposed approach indicate preferences of specific classifiers used in the processing of sEMG data. The proposed methods are implemented in a virtual reality environment allowing for potential selection and training of prosthetic device usage as well as for physical therapy rehabilitation sessions of stroke victims.

Sensory stimulation for upper limb amputations modulates adaptability of cortical large-scale systems and combination of somatosensory and visual inputs

Touch-like phantom limb sensations can be elicited through targeted transcutaneous electrical nerve stimulation (tTENS) in individuals with upper limb amputation. The corresponding impact of sensory stimulation on cortical activity remains an open question. Brain network research shows that sensorimotor cortical activity is supported by dynamic changes in functional connections between relevant brain regions. These groups of interconnected regions are functional modules whose architecture enables specialized function and related neural processing supporting individual task needs. Using electroencephalographic (EEG) signals to analyze modular functional connectivity, we investigated changes in the modular architecture of cortical large-scale systems when participants with upper limb amputations performed phantom hand movements before, during, and after they received tTENS. We discovered that tTENS substantially decreased the flexibility of the default mode network (DMN). Furthermore, we found increased interconnectivity (measured by a graph theoretic integration metric) between the DMN, the somatomotor network (SMN) and the visual network (VN) in the individual with extensive tTENS experience. While for individuals with less tTENS experience, we found increased integration between DMN and the attention network. Our results provide insights into how sensory stimulation promotes cortical processing of combined somatosensory and visual inputs and help develop future tools to evaluate sensory combination for individuals with amputations.

Tennisgame Physio: A tool for amputees physiotherapy based on gamification

The present work aims to develop a computational solution in hardware and software that uses gamification methodologies to help physiotherapy professionals in the rehabilitation sessions of upper and lower limb amputees, who are in the pre-prosthetic and prosthetic stages. Thus, a table tennis match simulator is developed to instigate patients to reach the flow state during the session. Thus, a mobile program is developed to collect data from the smartphone’s gyroscope sensor and, through Bluetooth communication with the Arduino prototyping board, this information is forwarded to the simulator. The data received is used to move the virtual racket in the game. Furthermore, physiotherapists have a tool integrated with the tennis match simulator, to monitor the progress of patients during the sessions. In short, this solution turns out to be effective in helping both patients and physical therapists in physical rehabilitation sessions.

Kinematic analysis of impairments and compensatory motor behavior during prosthetic grasping in below-elbow amputees.

After a major upper limb amputation, the use of myoelectric prosthesis as assistive devices is possible. However, these prostheses remain quite difficult to control for grasping and manipulation of daily life objects. The aim of the present observational case study is to document the kinematics of grasping in a group of 10 below-elbow amputated patients fitted with a myoelectric prosthesis in order to describe and better understand their compensatory strategies. They performed a grasping to lift task toward 3 objects (a mug, a cylinder and a cone) placed at two distances within the reaching area in front of the patients. The kinematics of the trunk and upper-limb on the non-amputated and prosthetic sides were recorded with 3 electromagnetic Polhemus sensors placed on the hand, the forearm (or the corresponding site on the prosthesis) and the ipsilateral acromion. The 3D position of the elbow joint and the shoulder and elbow angles were calculated thanks to a preliminary calibration of the sensor position. We examined first the effect of side, distance and objects with non-parametric statistics. Prosthetic grasping was characterized by severe temporo-spatial impairments consistent with previous clinical or kinematic observations. The grasping phase was prolonged and the reaching and grasping components uncoupled. The 3D hand displacement was symmetrical in average, but with some differences according to the objects. Compensatory strategies involved the trunk and the proximal part of the upper-limb, as shown by a greater 3D displacement of the elbow for close target and a greater forward displacement of the acromion, particularly for far targets. The hand orientation at the time of grasping showed marked side differences with a more frontal azimuth, and a more "thumb-up" roll. The variation of hand orientation with the object on the prosthetic side, suggested that the lack of finger and wrist mobility imposed some adaptation of hand pose relative to the object. The detailed kinematic analysis allows more insight into the mechanisms of the compensatory strategies that could be due to both increased distal or proximal kinematic constraints. A better knowledge of those compensatory strategies is important for the prevention of musculoskeletal disorders and the development of innovative prosthetics.

The Upper Extremity Functional Scale for Prosthesis Users (UEFS-P): subscales for one and two-handed tasks

Purpose To develop a self-report measure of activity performance for upper limb prosthesis users that quantifies outcomes by level of amputation and prosthesis type. Materials and methods Telephone survey of 423 adults with major upper limb amputation (ULA) who used a prosthesis. Item generation, cognitive, and pilot testing were followed by field testing. Items were categorized as one- or two-handed. Factor and Rasch analyses evaluated unidimensionality, monotonicity, item fit, differential item functioning (DIF), and reliability. Test–retest reliability was evaluated with intraclass correlation coefficients (ICCs). Known group validity was assessed with ANOVAs. Results Respondents with unilateral ULA utilized prosthesis for 24% of unilateral and 38% of bilateral tasks. Those with bilateral ULA utilized prostheses for 64% of unilateral and 46% of bilateral tasks. Factor analyses identified a One-handed Task factor (CFI = 0.963, TLI = 0.950, and RMSEA = 0.064) and a Two-Handed Task factor (CFI = 0.958, TLI = 0.953, and RMSEA = 0.053). Response categories were collapsed to address monotonicity. After DIF adjustment, person reliability was 0.49 and 0.82 for One-handed and Two-handed Task scales, respectively, and ICCs were 0.88 and 0.91. Both scales differed by amputation level (p < 0.001). Conclusions The Upper Extremity Functional Scale for Prosthesis Users (UEFS-P) measure of upper limb function of prosthesis users has promising psychometric properties. Implications for rehabilitation Measurement of upper limb function in persons with amputation is challenging, given currently available measures which do not explicitly grade activity performance with a prosthesis. The Upper Extremity Functional Scale for Prosthesis Users (UEFS-P) builds upon the original Orthotics and Prosthetics User Survey (OPUS) UEFS Scale with modified instructions, a revised item set, response categories and scoring algorithm. The UEFS-P consists of two unidimensional scales, the One-handed Tasks scale and the Two-handed Tasks scale. The UEFS-P scales have clear advantages over existing self-report measures of upper limb function that ask about difficulty with performing functional activities without accounting for prosthesis use, and do not differentiate persons who use and do not use a prosthesis.

Virtual and Augmented Reality in Management of Phantom Limb Pain: A Systematic Review.

Upper and lower limb amputations are frequently associated with phantom limb pain (PLP). Recently, virtual reality (VR) and augmented reality (AR) have been reported as a potential therapy of PLP. We have conducted a systematic review of literature to evaluate the efficacy of VR and AR in managing PLP. Four databases were searched: PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and Web of Science. We utilized the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for our organization. The initial search resulted in 164 results. After title, abstract, and full-text screening, 9 studies were included. One study was of good quality and 8 studies were of fair to poor quality. Seven studies utilized VR and 2 studies utilized AR. The number of treatment sessions ranged from 1 to 28 and the duration ranged from 10 minutes to 2 hours. Several pain scales were used to evaluate PLP pre- and postintervention including Numeric Rating Scale, Pain Rating Index, McGill Pain Questionnaire, and Visual Analog Scale. All the studies reported improvement of PLP on one or more of pain scales after one or more sessions of VR or AR. Despite the promising results reported by literature, we cannot recommend using VR or AR for PLP. Most of the studies are of poor design and have limited sample size with high bias levels. Therefore, no substantial evidence can be derived from them. However, we do believe further research with high-quality randomized controlled trials should take place to increase the knowledge of the potential advantages.

A multiarticulate pediatric prosthetic hand for clinical and research applications.

Although beginning to emerge, multiarticulate upper limb prostheses for children remain sparse despite the continued advancement of mechatronic technologies that have benefited adults with upper limb amputations. Upper limb prosthesis research is primarily focused on adults, even though rates of pediatric prosthetic abandonment far surpass those seen in adults. The implicit goal of a prosthesis is to provide effective functionality while promoting healthy social interaction. Yet most current pediatric devices offer a single degree of freedom open/close grasping function, a stark departure from the multiple grasp configurations provided in advanced adult devices. Although comparable child-sized devices are on the clinical horizon, understanding how to effectively translate these technologies to the pediatric population is vital. This includes exploring grasping movements that may provide the most functional benefits and techniques to control the newly available dexterity. Currently, no dexterous pediatric research platforms exist that offer open access to hardware and programming to facilitate the investigation and provision of multi-grasp function. Our objective was to deliver a child-sized multi-grasp prosthesis that may serve as a robust research platform. In anticipation of an open-source release, we performed a comprehensive set of benchtop and functional tests with common household objects to quantify the performance of our device. This work discusses and evaluates our pediatric-sized multiarticulate prosthetic hand that provides 6 degrees of actuation, weighs 177g and was designed specifically for ease of implementation in a research or clinical-research setting. Through the benchtop and validated functional tests, the pediatric hand produced grasping forces ranging from 0.424-7.216N and was found to be comparable to the functional capabilities of similar adult devices. As mechatronic technologies advance and multiarticulate prostheses continue to evolve, translating many of these emerging technologies may help provide children with more useful and functional prosthesis options. Effective translation will inevitably require a solid scientific foundation to inform how best to prescribe advanced prosthetic devices and control systems for children. This work begins addressing these current gaps by providing a much-needed research platform with supporting data to facilitate its use in laboratory and clinical research settings.

Classification of Different Shoulder Girdle Motions for Prosthesis Control Using a Time-Domain Feature Extraction Technique

Abstract—The upper limb amputation exerts a significant burden on the amputee, limiting their ability to perform everyday activities, and degrading their quality of life. Amputee patients’ quality of life can be improved if they have natural control over their prosthetic hands. Among the biological signals, most commonly used to predict upper limb motor intentions, surface electromyography (sEMG), and axial acceleration sensor signals are essential components of shoulder-level upper limb prosthetic hand control systems. In this work, a pattern recognition system is proposed to create a plan for categorizing high-level upper limb prostheses in seven various types of shoulder girdle motions. Thus, combining seven feature groups, which are root mean square, four-order autoregressive, wavelength, slope sign change, zero crossing (ZC), mean absolute value, and cardinality. In this article, the time-domain features were first extracted from the EMG and acceleration signals. Then, the spectral regression (SR) and principal component analysis dimensionality reduction methods are employed to identify the most salient features, which are then passed to the linear discriminant analysis (LDA) classifier. EMG and axial acceleration signal datasets from six intact-limbed and four amputee participants exhibited an average classification error of 15.68 % based on SR dimensionality reduction using the LDA classifier.

Upper Limb Amputations Following Electric Burn: Experience Sharing from Tertiary Hospitals in Bangladesh

Introduction: High voltage electrical burn is one of the most devastating burn injuries involving upper limbs in Bangladesh. It causes serious disfigurement and may lead to loss of the whole upper limb. The aim of this study was to see the severity of electric burn injury involving upper limbs pausing amputations at different levels in two tertiary level referral hospitals of Bangladesh. Methods: A prospective observational study was designed to collect the data from Burn and Plastic Surgery Unit, Dhaka Medical College Hospital and Sheikh Hasina National Institute of Burn and Plastic Surgery from January 2019 to December 2019. One hundred and sixty-nine (169) patients with high voltage electrical burn injury involving upper limb underwent amputation were analyzed according to the severity based on clinical assessment. Results: Male predominance (89%) was observed where right upper limb was involved in 49% of the cases and in 11% cases amputation was bilateral. The most alarming finding was 57.4% patients were below the age of 21 years. Below elbow amputation was done in 48.5% cases followed by above elbow amputations in 32.54% cases. Conclusion: Male sex and younger age are the two most common association with electric burn and subsequent limb amputation. The incidence in higher in upper limbs. This study will help us to create the awareness and for prevention of electric burn. J Bangladesh Coll Phys Surg 2022; 40: 279-286

Closed-loop stimulation of lateral cervical spinal cord in upper-limb amputees to enable sensory discrimination: a case study

Modern myoelectric prosthetic hands have multiple independently controllable degrees of freedom, but require constant visual attention to use effectively. Somatosensory feedback provides information not available through vision alone and is essential for fine motor control of our limbs. Similarly, stimulation of the nervous system can potentially provide artificial somatosensory feedback to reduce the reliance on visual cues to efficiently operate prosthetic devices. We have shown previously that epidural stimulation of the lateral cervical spinal cord can evoke tactile sensations perceived as emanating from the missing arm and hand in people with upper-limb amputation. In this case study, two subjects with upper-limb amputation used this somatotopically-matched tactile feedback to discriminate object size and compliance while controlling a prosthetic hand. With less than 30 min of practice each day, both subjects were able to use artificial somatosensory feedback to perform a subset of the discrimination tasks at a success level well above chance. Subject 1 was consistently more adept at determining object size (74% accuracy; chance: 33%) while Subject 2 achieved a higher accuracy level in determining object compliance (60% accuracy; chance 33%). In each subject, discrimination of the other object property was only slightly above or at chance level suggesting that the task design and stimulation encoding scheme are important determinants of which object property could be reliably identified. Our observations suggest that changes in the intensity of artificial somatosensory feedback provided via spinal cord stimulation can be readily used to infer information about object properties with minimal training.

An Algorithm Approach to Phantom Limb Pain.

Phantom limb pain (PLP) is a common condition that occurs following both upper and lower limb amputation. First recognized and described in 1551 by Ambroise Pare, research into its underlying pathology and effective treatments remains a very active and growing field. To date, however, there is little consensus regarding the optimal management of phantom limb pain. With few large well-designed clinical trials of which to make treatment recommendations, as well as significant heterogeneity in clinical response to available treatments, the management of PLP remains challenging. Below we summarize the current state of knowledge in the field, as well as propose an algorithm for the approach to the treatment of PLP.

Upper-Limb Amputation Disrupts the Interhemispheric Structural Rather than Functional Connectivity.

Background: Recent neuroimaging studies on upper-limb amputation have revealed the reorganization of bilateral sensorimotor cortex after sensory deprivation, underpinning the assumption of changes in the interhemispheric connections. In the present study, using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), we aim to explore the alterations in the interhemispheric functional and structural connectivity after upper-limb amputation. Methods: Twenty-two upper-limb amputees and 15 age- and sex-matched healthy controls were recruited for MRI scanning. The amputees were further divided into subgroups by amputation side and residual limb pain (RLP). DTI metrics of corpus callosum (CC) subregions and resting-state functional connectivity (FC) between the bilateral sensorimotor cortices were measured for each participant. Linear mixed models were carried out to investigate the relationship of interhemispheric connectivity with the amputation, amputation side, and RLP. Results: Compared with healthy controls, upper-limb amputees showed lower axial diffusivity (AD) in CC subregions II and III. Subgroup analyses showed that the dominant hand amputation induced significant microstructural changes in CC subregion III. In addition, only amputees with RLP showed decreased fractional anisotropy and AD in CC, which was also correlated with the intensity of RLP. No significant changes in interhemispheric FC were found after upper-limb amputation. Conclusion: The present study demonstrated that the interhemispheric structural connectivity rather than FC degenerated after upper-limb amputation, and the degeneration of interhemispheric structural connectivity was shown to be relevant to the amputation side and the intensity of RLP. Impact statement Neuroimaging studies have revealed the functional reorganization of bilateral sensorimotor cortex after amputation, with expanded activation from the intact hemisphere to the deprived hemisphere. Our findings indicated a degeneration of interhemispheric white matter connections in upper-limb amputees, unveiling the underlying structural basis for bilateral functional reorganization after amputation.

부분적 절단 환자를 위한 손가락 의수의 모델링 및 시뮬레이션

The number of amputees is increasing globally due to various accidents or diseases such as diabetes. Among them, there are many patients with upper limb amputations, especially those with hand or finger amputations. As a result, it is highly possible that many people need prosthetic limbs. Most of the prosthetic limbs currently commercialized are products that implement only models without function. Additionally, prosthetic limbs, which have been actively studied in recent years, have many sensors and actuators, providing excellent capabilities inperforming various tasks. However, it is difficult for partial amputees such as finger amputations to use because it targets the entire hand under the wrist. Thus, we propose to develop a wearable finger that can be used by patients with partially amputated fingers. This paper designs the structure of the wearable finger prosthesis and performs the dynamic modeling of the linkage used in the structure. Also, simulation using RecurDyn software is conducted to estimate motion and contact force.

Synergistic Upper-Limb Functional Muscle Connectivity Using Acoustic Mechanomyography.

Functional muscle network is a critical concept in describing functional synergistic muscle synchronization and functional connectivity needed for the execution of complex motor tasks. Muscle network is typically derived from decomposition of intermuscular coherence (IMC) at different frequency bands of multichannel electromyography (EMG) measurements, which potentially limits out-of-clinic applications. In this investigation, we introduce muscle network analysis to assess the functional coordination and functional connectivity of muscles based on mechanomyography (MMG). We focus on a targeted group of muscles vital for activities of daily living (ADLs) in the upper-limb. Functional muscle networks are evaluated for ten able-bodied participants and three upper-limb amputees. Muscle activity was acquired from a custom-made wearable armband of MMG sensors placed over four superficial muscles around the forearm (flexor carpi radialis (FCR), brachioradialis (BR), extensor digitorum communis (EDC), and flexor carpi ulnaris (FCU)) while participants performed four different hand gestures. Muscle connectivity analysis at multiple frequency bands shows significant topographical differences across gestures for low (i.e., 5 Hz) and high (i.e., 12 Hz) activation frequencies as well as observable network differences between amputee and non-amputee subjects. Results demonstrate MMG can be used for the analysis of functional muscle connectivity and mapping of synergistic functional synchronization of upper-limb muscles in complex movement tasks. The new physiological modality provides key insights into neural circuitry of motor coordination. Findings further offer the concomitant outcomes of demonstrating feasibility of MMG to map muscle coherence from a neurophysiological perspective and providing a mechanistic basis for its translation in human-robot interface.