Reachable workspace and performance of upper limb (PUL) in duchenne muscular dystrophy

Draft Guidance for Industry Duchenne Muscular Dystrophy, Becker Muscular Dystrophy, and Related Dystrophinopathies - Developing Potential Treatments for the Entire Spectrum of Disease

Background

Duchenne muscular dystrophy (DMD) and related dystrophinopathies are neuromuscular conditions with great unmet medical needs that require the development of effective medical treatments.

Objective

To aid sponsors in clinical development of drugs and therapeutic biological products for treating DMD across the disease spectrum by integrating advancements, patient registries, natural history studies, and more into a comprehensive guidance.

Methods

This guidance emerged from collaboration between the FDA, the Duchenne community, and industry stakeholders. It entailed a structured approach, involving multiple committees and boards. From its inception in 2014, the guidance underwent revisions incorporating insights from gene therapy studies, cardiac function research, and innovative clinical trial designs.

Results

The guidance provides a deeper understanding of DMD and its variants, focusing on patient engagement, diagnostic criteria, natural history, biomarkers, and clinical trials. It underscores patient-focused drug development, the significance of dystrophin as a biomarker, and the pivotal role of magnetic resonance imaging in assessing disease progression. Additionally, the guidance addresses cardiomyopathy's prominence in DMD and the burgeoning field of gene therapy.

Conclusions

The updated guidance offers a comprehensive understanding of DMD, emphasizing patient-centric approaches, innovative trial designs, and the importance of biomarkers. The focus on cardiomyopathy and gene therapy signifies the evolving realm of DMD research. It acts as a crucial roadmap for sponsors, potentially leading to improved treatments for DMD.

Improved spatial-temporal graph convolutional networks for upper limb rehabilitation assessment based on precise posture measurement

After regular rehabilitation training, paralysis sequelae can be significantly reduced in patients with limb movement disorders caused by stroke. Rehabilitation assessment is the basis for the formulation of rehabilitation training programs and the objective standard for evaluating the effectiveness of training. However, the quantitative rehabilitation assessment is still in the experimental stage and has not been put into clinical practice. In this work, we propose improved spatial-temporal graph convolutional networks based on precise posture measurement for upper limb rehabilitation assessment. Two Azure Kinect are used to enlarge the angle range of the visual field. The rigid body model of the upper limb with multiple degrees of freedom is established. And the inverse kinematics is optimized based on the hybrid particle swarm optimization algorithm. The self-attention mechanism map is calculated to analyze the role of each upper limb joint in rehabilitation assessment, to improve the spatial-temporal graph convolution neural network model. Long short-term memory is built to explore the sequence dependence in spatial-temporal feature vectors. An exercise protocol for detecting the distal reachable workspace and proximal self-care ability of the upper limb is designed, and a virtual environment is built. The experimental results indicate that the proposed posture measurement method can reduce position jumps caused by occlusion, improve measurement accuracy and stability, and increase Signal Noise Ratio. By comparing with other models, our rehabilitation assessment model achieved the lowest mean absolute deviation, root mean square error, and mean absolute percentage error. The proposed method can effectively quantitatively evaluate the upper limb motor function of stroke patients.

"suMus," a novel digital system for arm movement metrics and muscle energy expenditure

Objective: In the field of non-treatable muscular dystrophies, promising new gene and cell therapies are being developed and are entering clinical trials. Objective assessment of therapeutic effects on motor function is mandatory for economical and ethical reasons. Main shortcomings of existing measurements are discontinuous data collection in artificial settings as well as a major focus on walking, neglecting the importance of hand and arm movements for patients' independence. We aimed to create a digital tool to measure muscle function with an emphasis on upper limb motility. Methods: suMus provides a custom-made App running on smartwatches. Movement data are sent to the backend of a suMus web-based platform, from which they can be extracted as CSV data. Fifty patients with neuromuscular diseases assessed the pool of suMus activities in a first orientation phase. suMus performance was hence validated in four upper extremity exercises based on the feedback of the orientation phase. We monitored the arm metrics in a cohort of healthy volunteers using the suMus application, while completing each exercise at low frequency in a metabolic chamber. Collected movement data encompassed average acceleration, rotation rate as well as activity counts. Spearman rank tests correlated movement data with energy expenditure from the metabolic chamber. Results: Our novel application "suMus," sum of muscle activity, collects muscle movement data plus Patient-Related-Outcome-Measures, sends real-time feedback to patients and caregivers and provides, while ensuring data protection, a long-term follow-up of disease course. The application was well received from the patients during the orientation phase. In our pilot study, energy expenditure did not differ between overnight fasted and non-fasted participants. Acceleration ranged from 1.7 ± 0.7 to 3.2 ± 0.5 m/sec² with rotation rates between 0.9 ± 0.5 and 2.0 ± 3.4 rad/sec. Acceleration and rotation rate as well as derived activity counts correlated with energy expenditure values measured in the metabolic chamber for one exercise (r = 0.58, p < 0.03). Conclusion: In the analysis of slow frequency movements of upper extremities, the integration of the suMus application with smartwatch sensors characterized motion parameters, thus supporting a use in clinical trial outcome measures. Alternative methodologies need to complement indirect calorimetry in validating accelerometer-derived energy expenditure data.

Use of the Kinect sensor measured three-dimensional reachable workspace to assess the upper extremity function in older adults

BACKGROUND

We explored the utility of Kinect sensor-based upper extremity reachable workspace measure in healthy adults aged over 65 years.

METHODS

Forty-three healthy older subjects (19 men and 24 women) aged over 65 years and 22 healthy young subjects (11 men and 11 women) were included. All participants were ambulatory and perform the activities of daily living independently. Three-dimensional reachable workspace data were acquired for both arms using the Kinect sensor. We evaluated hand grip strength, manual muscle shoulder strength, and the active shoulder ranges of motion of the dominant and non-dominant sides. We assessed upper limb function using the Disabilities of Arm, Shoulder, and Hand (DASH) instrument and the health-related quality of life employing the descriptive EQ-5D-5L system.

FINDINGS

The quadrant 3 relative surface area in older adults was significantly smaller than that of young adults (both dominant and non-dominant sides), while the total and quadrants 1, 2, and 4 relative surface areas did not differ between older and young adults. However, the quadrant 3 relative surface area did not correlate with the DASH or EQ5D scores. The total and quadrant 1, 2, and 4 relative surface areas of the dominant side significantly correlated with the DASH score. The quadrant 4 relative surface area of the dominant side significantly correlated with the EQ5D score.

INTERPRETATION

Kinect sensor-based, three-dimensional, reachable workspace analysis may be useful to evaluate upper limb function in older adults.

Sensor acquired reachable workspace in the elderly population: A cross-sectional observational study

The elderly population experiences a decline in upper extremity range of motion (ROM), impairing activities of daily living. The primary mode of quantification is by goniometer measurement. In this cross-sectional observation study, we investigate a sensor-acquired reachable workspace for assessing shoulder ROM decline in an elderly population in comparison to traditional measurements. Sixty-one healthy subjects aged ≥ 65 years were included and compared to a cohort of 39 younger subjects, aged 20 to 64. A sensor acquired reachable workspace using a Kinect motion capture camera measured the maximum reaching ability of both arms while in a seated position, measured in m2 and normalized to arm length to calculate a novel score defined as a relative surface area. This score approximates range of motion in the upper extremity. This measurement was compared to goniometer measurements, including active ROM in shoulder flexion and abduction. Total RSA shows moderate to strong correlation between goniometer in flexion and abduction in the dominant arm (R = 0.790 and R = 0.650, P < .001, respectively) and moderate correlations for the nondominant arm (R = 0.622 and R = 0.615, P < .001). Compared to the younger cohort, the elderly population demonstrated significantly reduced total RSA in the dominant arm (meanelderly = 0.774, SD = 0.09; meanyounger = 0.830, SD = 0.07, P < .001), with significant reductions in the upper lateral quadrant in both arms (dominant: meanelderly = 0.225, SD = 0.04; meanyounger = 0.241, SD = 0.01; P < .001; nondominant: meanelderly = 0.213, SD = 0.03; meanyounger = 0.228, SD = 0.01; P = .004). The test-retest reliability was strong for both dominant and nondominant total RSA (ICC > 0.762). The reachable workspace demonstrates promise as a simple and quick tool for clinicians to assess detailed and quantitative active shoulder ROM decline in the elderly population.

The Black Box of Technological Outcome Measures: An Example in Duchenne Muscular Dystrophy

Background:

Outcome measures for non-ambulant Duchenne muscular dystrophy (DMD) patients are limited, with only the Performance of the Upper Limb (PUL) approved as endpoint for clinical trials.

Objective:

We assessed four outcome measures based on devices developed for the gaming industry, aiming to overcome disadvantages of observer-dependency and motivation.

Methods:

Twenty-two non-ambulant DMD patients (range 8.6–24.1 years) and 14 healthy controls (HC; range 9.5–25.4 years) were studied at baseline and 16 patients at 12 months using Leap Motion to quantify wrist/hand active range of motion (aROM) and a Kinect sensor for reached volume with Ability Captured Through Interactive Video Evaluation (ACTIVE), Functional Workspace (FWS) summed distance to seven upper extremity body points, and trunk compensation (KinectTC). PUL 2.0 was performed in patients only. A stepwise approach assessed quality control, construct validity, reliability, concurrent validity, longitudinal change and patient perception.

Results:

Leap Motion aROM distinguished patients and HCs for supination, radial deviation and wrist flexion (range p = 0.006 to <0.001). Reliability was low and the manufacturer’s hand model did not match the sensor’s depth images. ACTIVE differed between patients and HCs (p < 0.001), correlated with PUL (rho = 0.76), and decreased over time (p = 0.030) with a standardized response mean (SRM) of –0.61. It was appraised as fun on a 10-point numeric rating scale (median 9/10). PUL decreased over time (p < 0.001) with an SRM of –1.28, and was appraised as fun (median 7/10). FWS summed distance distinguished patients and HCs (p < 0.001), but reliability in patients was insufficient. KinectTC differed between patients and HCs (p < 0.01), but correlated insufficiently with PUL (rho = –0.69).

Conclusions:

Only ACTIVE qualified as potential outcome measure in non-ambulant DMD patients, although the SRM was below the commonly used threshold of 0.8. Lack of insight in technological constraints due to intellectual property and software updates made the technology behind these outcome measures a kind of black box that could jeopardize long-term use in clinical development.

Healthcare applications of single camera markerless motion capture: a scoping review

Background

Single camera markerless motion capture has the potential to facilitate at home movement assessment due to the ease of setup, portability, and affordable cost of the technology. However, it is not clear what the current healthcare applications of single camera markerless motion capture are and what information is being collected that may be used to inform clinical decision making. This review aims to map the available literature to highlight potential use cases and identify the limitations of the technology for clinicians and researchers interested in the collection of movement data.

Survey Methodology

Studies were collected up to 14 January 2022 using Pubmed, CINAHL and SPORTDiscus using a systematic search. Data recorded included the description of the markerless system, clinical outcome measures, and biomechanical data mapped to the International Classification of Functioning, Disability and Health Framework (ICF). Studies were grouped by patient population.

Results

A total of 50 studies were included for data collection. Use cases for single camera markerless motion capture technology were identified for Neurological Injury in Children and Adults; Hereditary/Genetic Neuromuscular Disorders; Frailty; and Orthopaedic or Musculoskeletal groups. Single camera markerless systems were found to perform well in studies involving single plane measurements, such as in the analysis of infant general movements or spatiotemporal parameters of gait, when evaluated against 3D marker-based systems and a variety of clinical outcome measures. However, they were less capable than marker-based systems in studies requiring the tracking of detailed 3D kinematics or fine movements such as finger tracking.

Conclusions

Single camera markerless motion capture offers great potential for extending the scope of movement analysis outside of laboratory settings in a practical way, but currently suffers from a lack of accuracy where detailed 3D kinematics are required for clinical decision making. Future work should therefore focus on improving tracking accuracy of movements that are out of plane relative to the camera orientation or affected by occlusion, such as supination and pronation of the forearm.

MRI Assessment of Motor Capabilities in Patients with Duchenne Muscular Dystrophy According to the Motor Function Measure Scale

The research was aimed on the study of motor capabilities on the Motor Function Measure (MFM) scale in ambulant and non-ambulant patients with Duchenne muscular dystrophy, and to conduct a correlation analysis between the results of the MFM scale and Magnetic Resonance Imaging (MRI) data. A total of 46 boys who had genetically confirmed Duchenne muscular dystrophy (age from 2.1 to 16.7 years) and were in clinical rehabilitation were investigated. An assessment was performed according to the Motor Function Measure scale (subsections D1, D2, D3, and the total score), an MRI obtaining T1-VI of the muscles of the pelvic girdle was conducted, and the thighs and lower legs were further assessed in terms of the severity of fibrous-fat degeneration according to the Mercuri scale. In ambulant patients, the ability to stand up and move (D1) was 74.4%, axial and proximal motor functions (D2)—97.6%, distal motor functions (D3)—96.2%, and total score was 87.9%. In non-ambulant patients, the ability to stand up and move (D1) was 1.7%, axial and proximal motor functions (D2)—47%, distal motor functions (D3)—67.5%, and the total score—33.1%. A high inverse correlation (r = −0.7, p < 0.05) of the MRI data of the pelvic girdle and thighs with tasks D1, as well as a noticeable inverse correlation with tasks D2 (r = −0.6, p < 0.05) of the scale MFM, were revealed in the ambulant group of patients. In the non-ambulant group of patients, the MRI data of the lower legs muscles were characterized by a high inverse correlation (r = −0.7, p < 0.05) with tasks D3 and a noticeable inverse correlation (r = −0.6, p < 0.05) with tasks D1 of the MFM scale. Conclusion: The Motor Function Measure scale allows effective assessment of the motor capabilities of patients with Duchenne muscular dystrophy at different stages of the disease, which is confirmed by visualization of fibro-fatty muscle replacement.

Technology-outcome measures in neuromuscular disorders: a systematic review

BACKGROUND

Portable and wearable devices can monitor a number of physical performances and have been lately applied to patients with neuromuscular disorders (NMD).

METHODS

We performed a systematic search of literature databases following PRISMA principles, including all studies reporting the use of technological devices for motor function assessment in NMDs from 2000 to 2021. We also summarized the evidence on measurement properties (validity, reliability, responsiveness) of the analyzed technological outcome measures.

RESULTS

One-hundred studies fulfilled the selection criteria, most of them published in the last ten years. We defined four categories that gathered similar technologies: gait analysis tools, for clinical assessment of pace and posture; continuous monitoring of physical activity with inertial sensors, that allow "unsupervised" activity assessment; upper limb evaluation tools, including Kinect-based outcome measures to assess the reachable workspace; and new muscle strength assessment tools, such as Myotools. Inertial sensors have the evident advantage of being applied in the "in-home" setting, which has become especially appealing with the Covid-19 pandemic, although poor evidence from psychometric property assessment and results of the analyzed studies may limit their research application. Both Kinect-based outcome measures and Myotools have been already validated in multicenter studies and different NMDs, showing excellent characteristics for application in clinical trials.

CONCLUSION

This overview is intended to raise awareness on the potential of the different TOMs in the neuromuscular field and be an informative source for the design of future clinical trials, particularly in the era of telemedicine.

Instruments to assess upper-limb function in children and adolescents with neuromuscular diseases: a systematic review

AIM

To synthesize clinical and scientific evidence regarding the instruments available to assess upper-limb function in paediatric patients with neuromuscular disease (NMD).

METHOD

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines (Prospective Registry of Systematic Reviews no. CRD42020140343). Two independent reviewers searched the PubMed/MEDLINE, LILACS, Embase, and Scopus databases. Inclusion criteria were cross-sectional or longitudinal studies or randomized controlled trials that used scales or questionnaires to assess upper-limb function in paediatric patients with NMDs. The COSMIN Risk of Bias checklist and criteria for good measurement properties were applied to assess the methodological quality of the instruments.

RESULTS

In total, 34 articles and 12 instruments were included. The Brooke Upper Extremity (n=16) and Performance of Upper Limb (PUL) (n=12) instruments were the most used tools. The PUL and Duchenne muscular dystrophy (DMD) Upper Limb patient-reported outcome measures (PROMs) tested more measurement properties and provided higher methodological quality scores for patients with DMD. Likewise, the Revised Upper Limb Module (RULM) was the most suitable instrument for patients with spinal muscular atrophy. No instrument has been devised to assess upper-limb function in patients with Charcot-Marie-Tooth disease and no other disease-specific instruments were found.

INTERPRETATION

The PUL, DMD Upper Limb PROM, and RULM are the most suitable instruments to assess upper-limb function in the two most prevalent paediatric NMDs. The identified gaps and methodological flaws of the available instruments indicate a need to develop high-quality instruments to assess other types of paediatric NMDs. What this paper adds The most suitable observer-rater instrument to assess upper-limb function in Duchenne muscular dystrophy (DMD) is the Performance of Upper Limb. The most suitable observer-rater instrument to assess upper-limb function in spinal muscular atrophy is the Revised Upper Limb Module. The DMD Upper Limb patient-reported outcome measure is recommended to assess the upper-limb performance of patients with DMD. Literature gaps and methodological flaws indicate the need to develop high-quality instruments to assess other types of paediatric neuromuscular disease.

Alleviation of masticatory disturbance with an occlusal splint in a Duchenne muscular dystrophy patient

Aim

To present an occlusal splint effective for alleviating masticatory disturbance in Duchenne muscular dystrophy (DMD).

Case report

A 13‐year‐old male DMD patient with masticatory disturbance presented with an open bite, with occlusal contact only between the first and second molars bilaterally and reduced masticatory performance. We applied an occlusal splint that achieved occlusal contact for all teeth and monitored its effects on masticatory function over 6 years. The occlusal splint increased occlusal contact points from 11 to 60. Although occlusal force remained at 13.9‒16 kg, masticatory performance increased, and the number of mastication strokes increased from 124 to 169. Masseter muscle activity decreased from 76.8% to 33.4% maximum voluntary contraction (MVC) and digastric muscle activity increased from 8.7% to 18.0% MVC. Time from start of peanut mastication to swallowing decreased, and the vertical mastication cycle diameter and its width on the habitual side increased.

Conclusions

Masticatory disturbance in a DMD patient was alleviated using an occlusal splint. The number of mastication strokes and the digastric to masseter muscle activity ratio were increased. Furthermore, the mastication cycle was enlarged, which increased masticatory movement. As masseter muscle activity during mastication decreased, the occlusal splint likely reduced muscle fatigue during masticatory movement.

Reachable Workspace and Proximal Function Measures for Quantifying Upper Limb Motion

There are a lack of quantitative measures for clinically assessing upper limb function. Conventional biomechanical performance measures are restricted to specialist labs due to hardware cost and complexity, while the resulting measurements require specialists for analysis. Depth cameras are low cost and portable systems that can track surrogate joint positions. However, these motions may not be biologically consistent, which can result in noisy, inaccurate movements. This paper introduces a rigid body modelling method to enforce biological feasibility of the recovered motions. This method is evaluated on an existing depth camera assessment: the reachable workspace (RW) measure for assessing gross shoulder function. As a rigid body model is used, position estimates of new proximal targets can be added, resulting in a proximal function (PF) measure for assessing a subject's ability to touch specific body landmarks. The accuracy, and repeatability of these measures is assessed on ten asymptomatic subjects, with and without rigid body constraints. This analysis is performed both on a low-cost depth camera system and a gold-standard active motion capture system. The addition of rigid body constraints was found to improve accuracy and concordance of the depth camera system, particularly in lateral reaching movements. Both RW and PF measures were found to be feasible candidates for clinical assessment, with future analysis needed to determine their ability to detect changes within specific patient populations.

Test-retest reliability of the Performance of Upper Limb (PUL) module for muscular dystrophy patients

The Performance of the Upper Limb (PUL) module is an externally-assessed clinical scale, initially designed for the Duchenne muscular dystrophy population. It provides an upper extremity functional score suitable for both weaker ambulatory and non-ambulatory phases up to the severely impaired patients. It is capable of characterizing overall progression and severity of disease and of tracking the stereotypical proximal-to-distal progressive loss of upper limb function in muscular dystrophy. Since the PUL module has been validated only with Duchenne patients, its use also for Becker and Limb-Girdle muscular dystrophy patients has been here evaluated, to verify its reliability and extend its use. In particular, two different assessors performed this scale on 32 dystrophic subjects in two consecutive days. The results showed that the PUL module has high reliability, both absolute and relative, based on the calculation of Pearson's r (0.9942), Intraclass Correlation Coefficient (0.9943), Standard Error of Measurement (1.36), Minimum Detectable Change (3.77), and Coefficient of Variation (3%). The Minimum Detectable Change, in particular, can be used in clinical trials to perform a comprehensive longitudinal evaluation of the effects of interventions with the lapse of time. According to this analysis, an intervention is effective if the difference in the PUL score between subsequent evaluation points is equal or higher than 4 points; otherwise, the observed effect is not relevant. Inter-rater reliability with ten different assessors was evaluated, and it has been demonstrated that deviation from the mean is lower than calculated Minimum Detectable Change. The present work provides evidence that the PUL module is a reliable and valid instrument for measuring upper limb ability in people with different forms of muscular dystrophy. Therefore, the PUL module might be extended to other pathologies and reliably used in multicenter settings.

Depth Sensor-Based Assessment of Reachable Work Space for Visualizing and Quantifying Paretic Upper Extremity Motor Function in People With Stroke

BACKGROUND

Quantitative evaluation of upper extremity (UE) motor function is important in people with hemiparetic stroke. A depth sensor-based assessment of reachable work space (RWS) was applied to visualize and quantify paretic UE motor function.

OBJECTIVE

The objectives of this study were to examine the characteristics of RWS and to assess its validity, reliability, measurement error, and responsiveness in people with hemiparetic stroke.

DESIGN

This was a descriptive, repeated-measures, observational study.

METHODS

Fifty-eight people with stroke participated. RWS was assessed on both paretic and nonparetic UEs, and the RWS ratio was determined by dividing the RWS of the paretic UE by that of the nonparetic UE. The concurrent validity of the RWS was determined by examining the relationship with the Fugl-Meyer Assessment UE motor score. Test-retest reproducibility was examined in 40 participants. Responsiveness was determined by examining the RWS results before and after 3 weeks of intensive training of the paretic UE in 32 participants.

RESULTS

The lower area of RWS bordering shoulder was significantly larger than the upper area, and the medial-lower area of RWS bordering shoulder was significantly larger than the lateral-lower area. The RWS ratio was highly correlated with the Fugl-Meyer Assessment UE motor score (r = 0.81). The RWS ratio showed good intrarater relative reliability (intraclass correlation coefficient = 0.94) and no fixed or proportional bias. The minimal detectable change of the RWS ratio was 16.6. The responsiveness of the RWS ratio was large (standardized response mean = 0.83).

LIMITATIONS

Interexaminer reliability was not assessed.

CONCLUSIONS

The RWS assessment showed sufficient validity, reliability, and responsiveness in people with hemiparetic stroke. A depth sensor-based RWS evaluation is useful for visualizing and quantifying paretic UE motor function in the clinical setting.

Upper Limb Three-Dimensional Reachable Workspace Analysis Using the Kinect Sensor in Hemiplegic Stroke Patients: A Cross-Sectional Observational Study

OBJECTIVE

A reachable workspace evaluation using the Kinect sensor was previously introduced as a novel upper limb outcome measure in neuromuscular and musculoskeletal conditions. This study investigated its usefulness in hemiplegic stroke patients.

DESIGN

Forty-one patients with hemiplegic stroke were included. Kinect-based reachable workspace analysis was performed on both paretic and nonparetic sides. Upper limb impairment was measured using the Fugl-Meyer Assessment and the Motricity Index on the paretic side. Disability was assessed using the shortened Disabilities of the Arm, Shoulder, and Hand questionnaire. Correlations between the relative surface areas, impairment scores, and disability were analyzed.

RESULTS

Quadrants 1, 3, and 4 as well as the total relative surface area of the paretic side were significantly reduced compared with the nonparetic side. The total relative surface area of the paretic side correlated with the Fugl-Meyer Assessment scores, the Motricity Index for Upper Extremity, and the Disabilities of the Arm, Shoulder, and Hand questionnaire score. Furthermore, quadrant 3 was the most important determinant of upper limb impairment and disability.

CONCLUSIONS

A reachable workspace (a sensor-based measure that can be obtained relatively quickly and unobtrusively) could be a useful and alternative outcome measure for upper limb in hemiplegic stroke patients.

Validation of an ambient measurement system (AMS) for physical activities in a paediatric population

Ambient measurement systems (AMSs) can enable continuous assessment of functional performance at home, increasing the availability of data for monitoring of neuromuscular disease. An AMS passively measures movement whenever someone is in range of the sensor, without the need for any wearable sensors. The current study evaluates the performance of an AMS for three metrics associated with functional assessments in Duchenne muscular dystrophy (DMD): ambulation speed, rise-to-stand speed and arm-raise speed. Healthy paediatric subjects performed a series of functional tasks and were graded by both a human rater and an AMS. Linear mixed-effect models were fit to calculate agreement between the two measurement methods. For all activities, the AMS and human rater supplied similar measurements of average speed, with correlation coefficients of 0.76-0.92 and systematic differences ranging in magnitude from 0 to 0.48 m per second. The largest systematic difference was for the 10-m run, which was likely due to human rater reaction time. Systematic differences in arm-raise measurements were due to incomplete execution of movements by test participants. These results are consistent with previous studies comparing automated and manual measurements of movement. This study demonstrates that an AMS device is able to measure ambulation speed, rise-to-stand speed and arm-raise speed in a paediatric population in a controlled setting without the need for complicated installation, calibration or worn sensors.

Superficial Shoulder Muscle Synergy Analysis in Facioscapulohumeral Dystrophy During Humeral Elevation Tasks

Facioscapulohumeral dystrophy (FSHD) is a progressive muscle-wasting disease which leads to a decline in upper extremity functionality. Although the scapulohumeral joint's stability and functionality are affected, evidence on the synergetic control of the shoulder muscles in FSHD individuals is still lacking. The aim of this paper is to understand the neuromuscular changes in shoulder muscle control in people with FSHD. Upper arm kinematics and electromyograms (EMG) of eight upper extremity muscles were recorded during shoulder abduction-adduction and flexion-extension tasks in eleven participants with FSHD and 11 healthy participants. Normalized muscle activities were extracted from EMG signals. Non-negative matrix factorization was used to compute muscle synergies. Maximum muscle activities were compared using non-parametric analysis of variance. Similarities between synergies were also calculated using correlation. The Biceps Brachii was significantly more active in the FSHD group (25±2%) while Trapezius Ascendens and Serratus Anterior were less active (32±7% and 39±4%, respectively). Muscle synergy weights were altered in FSHD individuals and showed greater diversity while controls mostly used one synergy for both tasks. The decreased activity by selected scapula rotator muscles and muscle synergy weight alterations show that neuromuscular control of the scapulohumeral joint is less consistent in people with FSHD compared to healthy participants. Assessments of muscle coordination strategies can be used to evaluate motor output variability and assist in management of the disease.

Usefulness of Kinect sensor-based reachable workspace system for assessing upper extremity dysfunction in breast cancer patients

PURPOSE

Recently, the utility of the Kinect sensor-based reachable workspace analysis system for measuring upper extremity outcomes of neuromuscular and musculoskeletal diseases has been demonstrated. Here, we investigated its usefulness for assessing upper extremity dysfunction in breast cancer patients.

METHODS

Twenty unilateral breast cancer patients were enrolled. Upper extremity active range of motion was captured by the Kinect sensor, and reachable workspace relative surface areas (RSAs) were obtained. The QuickDASH was completed to assess upper extremity disability. General and breast cancer-specific quality of life (QOL) were assessed by the EORTC QLQ-C30 and EORTC QLQ-BR23.

RESULTS

The total RSA ratio of the affected and unaffected sides ranges from 0.64 to 1.11. Total RSA was significantly reduced on the affected versus unaffected side (0.659 ± 0.105 vs. 0.762 ± 0.065; p = 0.001). Quadrant 1 and 3 RSAs were significantly reduced (0.135 ± 0.039 vs. 0.183 ± 0.040, p < 0.001; 0.172 ± 0.058 vs. 0.217 ± 0.031, p = 0.006). Total RSA of the affected side was strongly correlated with the numeric pain rating scale during movement (r = - 0.812, p < 0.001) and moderately with the QuickDASH (r = - 0.494, p = 0.027). Further, quadrant 3 RSA was correlated with EORTC QLQ-C30 role functioning (r = 0.576, p = 0.008) and EORTC QLQ-BR23 arm symptoms (r = - 0.588, p = 0.006) scales.

CONCLUSIONS

The Kinect sensor-based reachable workspace analysis system was effectively applied to assess upper extremity dysfunction in breast cancer patients. This system could potentially serve as a quick and simple outcome measure that provides quantitative data for breast cancer patients.

Design and Analysis of Cloud Upper Limb Rehabilitation System Based on Motion Tracking for Post-Stroke Patients

In order to improve the convenience and practicability of home rehabilitation training for post-stroke patients, this paper presents a cloud-based upper limb rehabilitation system based on motion tracking. A 3-dimensional reachable workspace virtual game (3D-RWVG) was developed to achieve meaningful home rehabilitation training. Five movements were selected as the criteria for rehabilitation assessment. Analysis was undertaken of the upper limb performance parameters: relative surface area (RSA), mean velocity (MV), logarithm of dimensionless jerk (LJ) and logarithm of curvature (LC). A two-headed convolutional neural network (TCNN) model was established for the assessment. The experiment was carried out in the hospital. The results show that the RSA, MV, LC and LJ could reflect the upper limb motor function intuitively from the graphs. The accuracy of the TCNN models is 92.6%, 80%, 89.5%, 85.1% and 87.5%, respectively. A therapist could check patient training and assessment information through the cloud database and make a diagnosis. The system can realize home rehabilitation training and assessment without the supervision of a therapist, and has the potential to become an effective home rehabilitation system.

Respiratory and upper limb function as outcome measures in ambulant and non-ambulant subjects with Duchenne muscular dystrophy: A prospective multicentre study

The field of translational research in Duchenne muscular dystrophy (DMD) has been transformed in the last decade by a number of therapeutic targets, mostly studied in ambulant patients. A paucity of studies focus on measures that capture the non-ambulant stage of the disease, and the transition between the ambulant and non-ambulant phase. In this prospective natural history study, we report the results of a comprehensive assessment of respiratory, upper limb function and upper limb muscle strength in a group of 89 DMD boys followed in 3 European countries, 81 receiving corticosteroids, spanning a wide age range (5-18 years) and functional abilities, from ambulant (n = 60) to non-ambulant (n = 29). Respiratory decline could be detected in the early ambulatory phase using Peak Expiratory Flow percentage predicted (PEF%), despite glucocorticoid use (mean annual decline: 4.08, 95% CI [-7.44,-0.72], p = 0.02 in ambulant; 4.81, 95% CI [-6.79,-2.82], p < 0.001 in non-ambulant). FVC% captured disease progression in non-ambulant DMD subjects, with an annual loss of 5.47% (95% CI [-6.48,-4.45], p < 0.001). Upper limb function measured with the Performance of Upper Limb (PUL 1.2) showed an annual loss of 4.13 points (95% CI [-4.79,3.47], p < 0.001) in the non-ambulant cohort. Measures of upper limb strength (MyoGrip and MyoPinch) showed a continuous decline independent of the ambulatory status, when reported as percentage predicted (grip force -5.51%, 95% CI [-6.54,-4.48], p < 0.001 in ambulant and a slower decline -2.86%; 95% CI -3.29,-2.43, p < 0.001, in non-ambulant; pinch force: -2.66%, 95% CI [-3.82,-1.51], p < 0.001 in ambulant and -2.23%, 95% CI [-2.92,-1.53], p < 0.001 in non-ambulant). Furthermore, we also explored the novel concept of a composite endpoint by combining respiratory, upper limb function and force domains: we were able to identify clear clinical progression in patients in whom an isolated measurement of only one of these domains failed to appreciate the yearly change. Our study contributes to the field of natural history of DMD, linking the ambulant and non-ambulant phases of the disease, and suggests that composite scores should be explored further.

Kinect-based assessment of proximal arm non-use after a stroke

Background

After a stroke, during seated reaching with their paretic upper limb, many patients spontaneously replace the use of their arm by trunk compensation movements, even though they are able to use their arm when forced to do so. We previously quantified this proximal arm non-use (PANU) with a motion capture system (Zebris, CMS20s). The aim of this study was to validate a low-cost Microsoft Kinect-based system against the CMS20s reference system to diagnose PANU.

Methods

In 19 hemiparetic stroke individuals, the PANU score, reach length, trunk length, and proximal arm use (PAU) were measured during seated reaching simultaneously by the Kinect (v2) and the CMS20s over two testing sessions separated by two hours.

Results

Intraclass correlation coefficients (ICC) and linear regression analysis showed that the PANU score (ICC = 0.96, r² = 0.92), reach length (ICC = 0.81, r² = 0.68), trunk length (ICC = 0.97, r² = 0.94) and PAU (ICC = 0.97, r² = 0.94) measured using the Kinect were strongly related to those measured using the CMS20s. The PANU scores showed good test-retest reliability for both the Kinect (ICC = 0.76) and CMS20s (ICC = 0.72). Bland and Altman plots showed slightly reduced PANU scores in the re-test session for both systems (Kinect: − 4.25 ± 6.76; CMS20s: − 4.71 ± 7.88), which suggests a practice effect.

Conclusion

We showed that the Kinect could accurately and reliably assess PANU, reach length, trunk length and PAU during seated reaching in post stroke individuals. We conclude that the Kinect can offer a low-cost and widely available solution to clinically assess PANU for individualised rehabilitation and to monitor the progress of paretic arm recovery.

Trial registration

The study was approved by The Ethics Committee of Montpellier, France (N°ID-RCB: 2014-A00395–42) and registered in Clinical Trial (N° NCT02326688, Registered on 15 December 2014, https://clinicaltrials.gov/ct2/show/results/NCT02326688).

3D Analysis of Upper Limbs Motion during Rehabilitation Exercises Using the KinectTM Sensor: Development, Laboratory Validation and Clinical Application

Optoelectronic devices are the gold standard for 3D evaluation in clinics, but due to the complexity of this kind of hardware and the lack of access for patients, affordable, transportable, and easy-to-use systems must be developed to be largely used in daily clinics. The Kinect^TM sensor has various advantages compared to optoelectronic devices, such as its price and transportability. However, it also has some limitations: (in)accuracy of the skeleton detection and tracking as well as the limited amount of available points, which makes 3D evaluation impossible. To overcome these limitations, a novel method has been developed to perform 3D evaluation of the upper limbs. This system is coupled to rehabilitation exercises, allowing functional evaluation while performing physical rehabilitation. To validate this new approach, a two-step method was used. The first step was a laboratory validation where the results obtained with the Kinect^TM were compared with the results obtained with an optoelectronic device; 40 healthy young adults participated in this first part. The second step was to determine the clinical relevance of this kind of measurement. Results of the healthy subjects were compared with a group of 22 elderly adults and a group of 10 chronic stroke patients to determine if different patterns could be observed. The new methodology and the different steps of the validations are presented in this paper.

Telehealth applications for outpatients with neuromuscular or musculoskeletal disorders

Telehealth describes the provision of medical services remotely through technology, and may enhance patient access to specialty care services. Although teleneurology has expanded widely since the introduction of telestroke in 1999, telehealth services for outpatients with neuromuscular or musculoskeletal disorders are less widespread. In this narrative review, we will describe the current technology, applications, outcomes, and limitations of this dynamically growing field. Evidence for telehealth applications related to neuromuscular diseases, palliative care, specialized multidisciplinary services, and musculoskeletal care are reviewed. With growing demand for specialized services and finite resources, telehealth provides a promising avenue to promote access to high-quality care, decrease the cost and burden of travel for patients, and with the expansion of software to personal computing and mobile devices, offer flexible, low-overhead practice opportunities for clinicians. Providers embarking on careers in telehealth should be aware of current legal restrictions impacting care to minimize risk and avoid liability. Muscle Nerve 58: 475-485, 2018.

Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and neuromuscular, rehabilitation, endocrine, and gastrointestinal and nutritional management

Since the publication of the Duchenne muscular dystrophy (DMD) care considerations in 2010, multidisciplinary care of this severe, progressive neuromuscular disease has evolved. In conjunction with improved patient survival, a shift to more anticipatory diagnostic and therapeutic strategies has occurred, with a renewed focus on patient quality of life. In 2014, a steering committee of experts from a wide range of disciplines was established to update the 2010 DMD care considerations, with the goal of improving patient care. The new care considerations aim to address the needs of patients with prolonged survival, to provide guidance on advances in assessments and interventions, and to consider the implications of emerging genetic and molecular therapies for DMD. The committee identified 11 topics to be included in the update, eight of which were addressed in the original care considerations. The three new topics are primary care and emergency management, endocrine management, and transitions of care across the lifespan. In part 1 of this three-part update, we present care considerations for diagnosis of DMD and neuromuscular, rehabilitation, endocrine (growth, puberty, and adrenal insufficiency), and gastrointestinal (including nutrition and dysphagia) management.

Development of a 3D workspace shoulder assessment tool incorporating electromyography and an inertial measurement unit-a preliminary study

Traditional shoulder range of movement (ROM) measurement tools suffer from inaccuracy or from long experimental setup times. Recently, it has been demonstrated that relatively low-cost wearable inertial measurement unit (IMU) sensors can overcome many of the limitations of traditional motion tracking systems. The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. Six volunteer subjects with healthy shoulders and one participant with a ‘frozen’ shoulder were recruited to the study. Arm movement in 3D space was plotted in spherical coordinates while the relative EMG intensity of any arm position is presented graphically. The results showed that there was an average ROM surface area of 27291 ± 538 deg² among all six healthy individuals and a ROM surface area of 13571 ± 308 deg² for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace.

Graphical abstract