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BACKGROUND: Work-related musculoskeletal disorders (WRMSDs) remain a challenge despite research aimed at improving their prevention and treatment. Extrinsic feedback has been suggested for the prevention and rehabilitation of WRMSDs to improve sensorimotor control, and ultimately to reduce pain and disability. However, there are few systematic reviews on the effectiveness of extrinsic feedback for WRMSDs. OBJECTIVE: To perform a systematic review investigating the effect of extrinsic feedback for the prevention and rehabilitation of WRMSDs. METHODS: Five databases (CINAHL, Embase, Ergonomics Abstract, PsycInfo, PubMed) were searched. Studies of various designs assessing the effects of extrinsic feedback during work tasks on three outcomes (function, symptoms, sensorimotor control) in the context of prevention and rehabilitation of WRMSDs were included. RESULTS: Forty-nine studies were included, for a total sample of 3387 participants (including 925 injured) who performed work-related tasks in the workplace (27 studies) or in controlled environments (22 studies). The use of extrinsic feedback was shown to be effective in controlled environments for short-term prevention of functional limitations and sensorimotor alterations (very limited to moderate evidence) and for improving, in injured participants, function, symptoms and sensorimotor control (moderate evidence). In the workplace, it was shown to be effective for short-term prevention of functional limitations (limited evidence). There was conflicting evidence regarding its effect for WRMSD rehabilitation in the workplace. CONCLUSION: Extrinsic feedback is an interesting complementary tool for the prevention and rehabilitation of WRMSDs in controlled environments. More evidence is needed regarding its effect for the prevention and rehabilitation of WRMSDs in the workplace.

The corticospinal tract has been shown to be involved in normal walking in humans. However, its contribution during more challenging locomotor tasks is still unclear. As the corticospinal tract can be a potential target to promote gait recovery after neurological injury, it is of primary importance to quantify its use during human walking. The aims of the current study were to: (1) quantify the effects of precision walking on corticospinal excitability as compared to normal walking; (2) assess if corticospinal modulation is related to task difficulty or participants’ performance. Sixteen healthy participants walked on a treadmill during 2 tasks: regular walking (simple task) and stepping onto virtual targets (precision task). Virtual targets appeared randomly at 3 different step lengths: preferred, and ±20%. To assess corticospinal excitability, 25 motor evoked potentials (MEPs) were recorded from the tibialis anterior muscle in each task during walking. Performance for each participant (global success score; % of target hit) and task difficulty related to step length adjustments (success score for each step length) were also calculated. MEP size was larger during the precision task in all participants (mean increase of 93% ± 72%; P .05). In conclusion, corticospinal excitability exhibits a large increase during the precision task. This effect needs to be confirmed in neurological populations to potentially provide a simple and non-invasive approach to increase corticospinal drive during gait rehabilitation.

Study Design Participatory design. Objectives Activity-based therapies (ABT) have physical and psychosocial benefits for individuals with spinal cord injury (SCI). A Canadian ABT summit was held to: (1) identify methods used in stroke rehabilitation that may be appropriate for SCI; (2) understand the current state of ABT activities in Canada; and (3) identify priorities for ABT research and care for the next five years. Setting Stakeholder-engaged meeting at a tertiary rehabilitation hospital. Methods Thirty-nine stakeholders, including individuals with SCI, frontline clinicians, healthcare administrators, researchers, funders and health policy experts, attended. Two participants were note-takers. Priority identification occurred through input from stakeholder groups, followed by individual voting. Conventional content analysis was used to synthesize the information in the meeting notes. Results The strengths of ABT in stroke rehabilitation included clear and clinically feasible definitions, measurements and interventions, and recognized requirements for implementation (e.g. behavior change, partnerships). Knowledge gaps concerning ABT activities in Canada were identified for acute and community settings, non-traumatic populations, and the interventions, equipment and standardized measures (i.e. upper limb, activity levels) used. Five priorities for ABT across the continuum of care were identified: (1) Identify current ABT activities; (2) Create a network to facilitate dialog; (3) Track engagement in ABT activities; (4) Develop and implement best practice recommendations; and (5) Study optimal timing, methods, and dose of ABT. Working groups were formed to address priorities 1–3. Conclusions The priorities will guide SCI research and care activities in Canada over the next five years. Sponsorship Praxis Spinal Cord Institute.

Background Wearable powered exoskeletons represent a promising rehabilitation tool for locomotor training in various populations, including in individuals with a spinal cord injury. The lack of clear evidence on how to implement a locomotor powered exoskeleton training program raises many challenges for patients, clinicians and organizations. Objective To report determinants of implementation in clinical practice of an overground powered exoskeleton locomotor training program for persons with a spinal cord injury. Data sources Medline, CINAHL, Web of Science. Study selection Studies were included if they documented determinants of implementation of an overground powered exoskeleton locomotor training program for individuals with spinal cord injury. Data extraction Eligible studies were identified by two independent reviewers. Data were extracted by one reviewer, based on constructs of the Consolidated Framework for Implementation Research, and validated by a second reviewer. Results Sixty-three articles were included. 49.4% of all determinants identified were related to the intervention characteristics, 29.6% to the individuals’ characteristic and 13.5% to the inner setting. Recurrent barriers identified were the high prevalence of adverse events (e.g., skin issues, falls) and device malfunctions. Adequate training for clinicians, time and resource available, as well as discussion about patients’ expectations were identified as facilitators. Conclusions Powered exoskeleton training is a complex intervention. The limited information on the context and the implementation process domains may represent a barrier to a successful transition from knowledge to action.

BACKGROUND AND OBJECTIVE Pain influences motor control. Previous reviews observed that pain reduces the excitability of corticospinal projections to muscles tested with transcranial magnetic stimulation. However, the independent effect of the type of pain models (tonic, phasic), pain location and tissues targeted (e.g. muscle, skin) remains unexplored. The objective of this review was to determine the influence of experimental pain and of different methodological factors on the corticospinal excitability. DATABASES AND DATA TREATMENT Three electronic databases were searched: Embase, Pubmed and Web of Science. Meta-analyses were conducted in three consecutive steps to reduce methodological variability: (a) all studies; (b) same pain location; (c) same tissues, pain location and muscle state. Strength of evidence was assessed for each analysis performed. RESULTS Forty studies were included in the review and 26 in the meta-analysis as it focused only on studies using tonic pain. Overall, there was conflicting/moderate evidence of a diminution of corticospinal excitability during and after tonic pain. When considering only pain location, tonic hand and face pain induced a reduction in corticospinal excitability (limited evidence). Both muscle and cutaneous hand pain reduced corticospinal excitability (limited/conflicting evidence). Similar results were observed for phasic pain (limited evidence). CONCLUSIONS Our results confirm the inhibitory effect of pain on corticospinal excitability for both tonic and phasic pain. This reduction was specific to hand and face pain. Also, both cutaneous and muscle hand pain reduced excitability. The strength of evidence remains limited/conflicting. More high-quality studies are needed to confirm our conclusions. SIGNIFICANCE This study adds evidence on the effect of specific factors on the modulation of corticospinal excitability during/after experimental pain. The reduction in corticospinal excitability was driven by hand and face pain. We confirmed previous results that muscle pain reduces corticospinal excitability and provided evidence of a similar effect for cutaneous pain. Both models may inform on the influence of different types of pain on motor control. Future studies are needed to determine the origin of the effect of pain.

Physical interactions within virtual environments are often limited to visual information within a restricted workspace. A new system exploiting a cable-driven parallel robot to combine visual and haptic information related to environmental physical constraints (e.g. shelving, object weight) was developed. The aim of this study was to evaluate the impact on user movement patterns of adding haptic feedback in a virtual environment with this robot. Twelve healthy participants executed a manual handling task under three conditions: 1) in a virtual environment with haptic feedback; 2) in a virtual environment without haptic feedback; 3) in a real physical environment. Temporal parameters (movement time, peak velocity, movement smoothness, time to maximum flexion, time to peak wrist velocity) and spatial parameters of movement (maximum trunk flexion, range of motion of the trunk, length of the trajectory, index of curvature and maximum clearance from the shelf) were analysed during the reaching, lowering and lifting phases. Our results suggest that adding haptic feedback improves spatial parameters of movement to better respect the environmental constraints. However, the visual information presented in the virtual environment through the head mounted display appears to have an impact on temporal parameters of movement leading to greater movement time. Taken together, our results suggest that a cable-driven robot can be a promising device to provide a more ecological context during complex tasks in virtual reality.

A growing number of people all over the world are running. Gathering in-field data with wearable sensors is attractive for runners, clinicians and coaches to improve running performance, avoid injury or return to running after an injury. However, it is yet to be proven that commercially available wearable sensors provide valid data. The objective of this study was to assess the validity of five wearable sensors (Moov Now™, MilestonePod, RunScribe™, TgForce and Zoi) to measure ground reaction force related metrics, step rate, foot strike pattern, and vertical displacement of the center of mass during running. Concurrent/criterion validity was assessed against a laboratory-based system using Pearson’s correlation coefficients and ANOVAs. Step rate measurement provided by all wearable sensors was valid (all r > 0.96 and p < 0.001). Only Zoi provided valid vertical displacement of the center of mass (r = 0.81, p < 0.001); only TgForce provided meaningful estimates of instantaneous vertical loading rate (r = 0.76, p < 0.001); only MilestonePod could discriminate between a rear-, mid- and fore-foot strike pattern during running (p < 0.001). None of the wearable sensors was valid for estimating peak braking force. In conclusion, only a few metrics provided by these commercially available wearable sensors are valid. Potential buyers should therefore be aware of such limitations when monitoring running gait variables.

Most studies addressing the role of vestibulospinal reflexes in balance maintenance have mainly focused on responses in the lower limbs, while limited attention has been paid to the output in trunk and back muscles. To address this issue, we tested whether electromyographic (EMG) responses to galvanic vestibular stimulations (GVS) were modulated similarly in back and leg muscles, in situations where the leg muscle responses to GVS are known to be attenuated. Body sway and surface EMG signals were recorded in the paraspinal and limb muscles of humans (

Cross-sectional and longitudinal (exploratory) studies.Rotator cuff (RC) tendinopathy is the most prevalent shoulder diagnosis, and proprioception deficits are often observed in individuals with RC tendinopathy.This study aimed to evaluate upper limb proprioception during a multijoint task in participants with and without RC tendinopathy and to determine if symptoms, functional limitations, and proprioception are improved after a rehabilitation program.Twenty participants with and 20 without RC tendinopathy were recruited for the cross-sectional study, and 23 participants with RC tendinopathy were recruited for the longitudinal study. Proprioception was evaluated by an active joint-repositioning task: The upper limb was passively moved to a predetermined position, and the participant was asked to actively replicate the movement. The difference between the predetermined position and the replicated position was measured. The mean errors in positions of lateral, medial, and neutral rotation of the shoulder and the global mean error were reported. In addition to the active-repositioning assessment in the longitudinal study, symptoms and functional limitations were evaluated by the Disability of the Arm Shoulder and Hand questionnaire.Significant deficits in active repositioning (p .01), independent of the position, were observed in participants with RC tendinopathy compared with controls. The DASH score was improved after rehabilitation intervention (p .001), and patients with active-repositioning deficits at baseline had reduced repositioning error (p .05).Upper limb active joint repositioning was impaired in participants with RC tendinopathy. Symptoms and functional limitations and active joint repositioning in participants with RC tendinopathy and initial deficits were improved after a 6-week global rehabilitation program.

A new non-invasive and flexible sensor was fabricated to monitor the muscular activity of upper body muscles. It consists of a dry electrode made of multimaterial metal-polymer-glass hollow-core fiber electrodes connected to a custom made signal acquisition platform. This fiber electrode only adds a negligible contribution to the recording system’s internal noise ( $7.626~\mu \text{V}$ peak-to-peak and $1.234~\mu \text{V}$ RMS; recording system noise: $6.901~\mu \text{V}$ peak-to-peak and $1.205~\mu \text{V}$ RMS). Surface electromyograms (sEMGs) of the biceps bracci and trapezius muscles were recorded during maximal voluntary contractions using the new sensor and compared to that obtained with medical grade commercial sensors. Frequency content and time domain analysis show that the new flexible sensor performs similarly to commercial devices in terms of sEMG signal amplitude discrimination and frequency shift evaluation during the development of muscle fatigue. The advantage of the new sensor is the high flexibility of the fibers allowing their easy integration into stretchable garments without compromising the user’s comfort. This will lead to the development of a new generation of smart textile with large application for telemedicine and assistive devices.

Background People with chronic shoulder pain have been shown to present with motor adaptations during arm movements. These adaptations may create abnormal physical stress on shoulder tendons and muscles. However, how and why these adaptations develop from the acute stage of pain is still not well‐understood. Objective To investigate motor adaptations following acute experimental shoulder pain during upper limb reaching. Methods Forty participants were assigned to the Control or Pain group. They completed a task consisting of reaching targets in a virtual reality environment at three time points: (1) baseline (both groups pain‐free), (2) experimental phase (Pain group experiencing acute shoulder pain induced by injecting hypertonic saline into subacromial space), and (3) Post experimental phase (both groups pain‐free). Electromyographic (EMG) activity, kinematics, and performance data were collected. Results The Pain group showed altered movement planning and execution as shown by a significant increased delay to reach muscles EMG peak and a loss of accuracy, compared to controls that have decreased their mean delay to reach muscles peak and improved their movement speed through the phases. The Pain group also showed protective kinematic adaptations using less shoulder elevation and elbow flexion, which persisted when they no longer felt the experimental pain. Conclusion Acute experimental pain altered movement planning and execution, which affected task performance. Kinematic data also suggest that such adaptations may persist over time, which could explain those observed in chronic pain populations., Acute experimental pain alters movement planning and execution. Kinematic data suggest that motor adaptations may persist over time, which could explain those observed in chronic pain populations.

Work-related upper extremity disorders are costly to society due to resulting medical costs, presenteeism and absenteeism. Although their aetiology is likely multifactorial, physical workplace factors are known to play an important role in their development. Promising options for preventing work-related upper extremity disorders include assistive technologies such as dynamic arm supports designed to follow the movement of the arm while compensating for its weight. The objective of this study was to assess the effects of a dynamic arm support on perceived exertion, muscle activity and movement patterns of the upper limb during repetitive manual tasks in healthy individuals. Thirty healthy right-handed individuals were allocated either a static or a dynamic task to perform with and without a dynamic arm support. During the task, surface electromyographic activity (anterior and middle deltoid, upper trapezius) and upper limb kinematics (elbow, shoulder, sternoclavicular) were measured using surface EMG and inertial sensors. Results showed that the dynamic arm support significantly reduced perceived exertion during the tasks and limited the development of muscular fatigue of the anterior and middle deltoid as demonstrated by EMG signal mean epoch amplitudes and median frequency of the EMG power spectrum. The dynamic arm support also prevented a decrease in shoulder elevation and an increase in total shoulder joint excursion during static and dynamic task, respectively. These results denote the potential benefits of dynamic arm supports in work environments. Further studies should focus on their efficacy, acceptability and implementability in work settings.

The present study used coherence and directionality analyses to explore whether the motor cortex contributes to plantar flexor muscle activity during the stance phase and push-off phase during gait. Subjects walked on a treadmill, while EEG over the leg motorcortex area and EMG from the medial gastrocnemius and soleus muscles was recorded. Corticomuscular and intermuscular coherence were calculated from pair-wise recordings. Significant EEG-EMG and EMG-EMG coherence in the beta and gamma frequency bands was found throughout the stance phase with the largest coherence towards push-off. Analysis of directionality revealed that EEG activity preceded EMG activity throughout the stance phase until the time of push-off. These findings suggest that the motor cortex contributes to ankle plantar flexor muscle activity and forward propulsion during gait.

Kinesiotaping is widely used for the rehabilitation of rotator cuff tendinopathy. It has been argued to reduce symptoms and functional limitations through improvement of proprioceptive feedback. In addition, kinesiotaping has been reported to increase the subacromial space in healthy subjects. However, its effects on the acromiohumeral distance and shoulder proprioception of individuals with rotator cuff tendinopathy have not been ascertained. This study investigated the immediate effects of kinesiotaping on the acromiohumeral distance and shoulder proprioception in individuals with rotator cuff tendinopathy.Twenty-two individuals with chronic rotator cuff tendinopathy were included. The acromiohumeral distance was measured using an ultrasound scanner at rest and 60° shoulder abduction. Proprioception was measured through active joint repositioning in low- (45°-65°) and mid-amplitude (80°-100°) of shoulder flexion and abduction. A wireless inertial measurement unit system was used to quantify shoulder angles. First, measurements were taken without kinesiotaping. Thereafter, kinesiotaping was applied on the symptomatic shoulder, and the same measurements were retaken. Repeated measures ANOVAs were used for statistical analyses.Kinesiotaping induced a significant increase in acromiohumeral distance at 60° abduction (∆AHD = 0.94 mm; 95%CI: 0.50-1.38, p 0.001), exceeding the minimal detectable change (0.70 mm). No significant difference was observed in acromiohumeral distance at rest or in proprioception during active joint repositioning in both low- and mid-amplitude (p 0.05).Kinesiotaping led to an immediate increase in acromiohumeral distance at 60° of abduction that, although it seems a minor change (↑10.5%), it may be significant for symptomatic patients, whereas it had no immediate effect on active joint repositioning.

OCCUPATIONAL APPLICATIONSMilitary load carriage increases musculoskeletal injury risk and reduces performance, but is essential for operational effectiveness. Exoskeletons may play a role in reducing soldier burden. We found that wearing a customized passive exoskeleton during a military obstacle course decreased overall performance compared to a mass-matched control condition. Specifically, the "Stairs and Ladder" and "Hatch and Tunnel" obstacles were performed slower while wearing the exoskeleton. In contrast, similar mean completion times in the "Casualty Drag," "Sprint" and "Agility Run" obstacles were found in both the exoskeleton and control conditions. Acceptability of equipment weight and torso stiffness were rated similarly across conditions, whereas the acceptability of overall performance was rated lowest while wearing the exoskeleton. The results of this preliminary investigation suggest that the time to complete operationally-relevant military obstacles was not improved by wearing a passive exoskeleton.

Background: A popular outcome in rehabilitation studies is the activity intensity count, which is typically measured from commercially available accelerometers. However, the algorithms are not openly available, which impairs long-term follow-ups and restricts the potential to adapt the algorithms for pathological populations. The objectives of this research are to design and validate open-source algorithms for activity intensity quantification and classification. Methods: Two versions of a quantification algorithm are proposed (fixed [FB] and modifiable bandwidth [MB]) along with two versions of a classification algorithm (discrete [DM] vs. continuous methods [CM]). The results of these algorithms were compared to those of a commercial activity intensity count solution (ActiLife) with datasets from four activities (n = 24 participants). Results: The FB and MB algorithms gave similar results as ActiLife (r &gt, 0.96). The DM algorithm is similar to a ActiLife (r &ge, 0.99). The CM algorithm differs (r &ge, 0.89) but is more precise. Conclusion: The combination of the FB algorithm with the DM results is a solution close to that of ActiLife. However, the MB version remains valid while being more adaptable, and the CM is more precise. This paper proposes an open-source alternative for rehabilitation that is compatible with several wearable devices and not dependent on manufacturer commercial decisions.

Background Robotic devices are often used in rehabilitation and might be efficient to improve walking capacity after stroke. Objective First to investigate the effects of robot-assisted gait training after stroke and second to explain the observed heterogeneity of results in previous meta-analyses. Methods All randomized controlled trials investigating exoskeletons or end-effector devices in adult patients with stroke were searched in databases (MEDLINE, EMBASE, CENTRAL, CINAHL, OPENGREY, OPENSIGLE, PEDRO, WEB OF SCIENCE, CLINICAL TRIALS, conference proceedings) from inception to November 2019, as were bibliographies of previous meta-analyses, independently by 2 reviewers. The following variables collected before and after the rehabilitation program were gait speed, gait endurance, Berg Balance Scale (BBS), Functional Ambulation Classification (FAC) and Timed Up and Go scores. We also extracted data on randomization method, blinding of outcome assessors, drop-outs, intention (or not) to treat, country, number of participants, disease duration, mean age, features of interventions, and date of outcomes assessment. Results We included 33 studies involving 1466 participants. On analysis by subgroups of intervention, as compared with physiotherapy alone, physiotherapy combined with body-weight support training and robot-assisted gait training conferred greater improvement in gait speed (+0.09 m/s, 95% confidence interval [CI] 0.03 to 0.15; p = 0.002), FAC scores (+0.51, 95% CI 0.07 to 0.95; p = 0.022) and BBS scores (+4.16, 95% CI 2.60 to 5.71; p = 0.000). A meta-regression analysis suggested that these results were underestimated by the attrition bias of studies. Conclusions Robot-assisted gait training combined with physiotherapy and body-weight support training seems an efficient intervention for gait recovery after stroke.

A new multi-material polymer fiber electrode has been developed for smart clothing applications. The conductive fiber is optimized for bipotential measurements such as surface electromyogram (sEMG) and electrocardiogram (ECG). The main benefit of this fiber is its flexibility and being a dry and non-obtrusive electrode. It can be directly integrated into a garment to make a smart textile for real time biopoten-tial monitoring. A customized wireless electronic system has been developed to acquire electrophysiological signal from the fiber. The receiver base station is connected to a PC host running Matlab. The multi-material polymer fiber electrode recording setting were first optimized in length and inter-electrode distance by recording different sEMG signals. The typical sEMG signal to noise ratio ranges from 19.1 dB to 33.9 dB depending on the geometry. These value are comparable with those obtained with Ag/AgCl electrodes and dry electrode-base commercial system such as Delsys Trigno. The frequency domain analysis obtained from the power spectral density reveals that the new flexible fiber-electrode enables high sEMG signals recording quality while being suitable for integration in smart clothing fabric. A muscle fatigue analysis and ECG recording are also presented in this study. The multi-material polymer fiber electrodes demonstrate a viable solution for sEMG and ECG data acquisition.

Background: Kinesiotaping (KT) has been widely used in clinical practice. Current evidence is insufficient to support the use of KT for treating rotator cuff–related shoulder pain (RCRSP), as its mid- and long-term effects have not been investigated. Hypotheses: Individuals using KT will achieve faster improvements in symptoms and functional limitations compared with those not using it. They will also present a greater increase in pain-free range of motion (ROM) and acromiohumeral distance (AHD) at the end of the treatment. Study Design: Randomized controlled trial (NCT02881021). Level of evidence: Therapy, level 1b. Methods: A total of 52 individuals with RCRSP, randomly assigned to 1 of 2 groups (experimental: KT; control: no-KT), underwent a 6-week rehabilitation program composed of 10 physical therapy sessions. KT was added to the treatment of the KT group. Symptoms and functional limitations were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire (primary outcome); Brief Pain Inventory (BPI); and Western Ontario Rotator Cuff (WORC) index at baseline, 3 weeks, 6 weeks, 12 weeks, and 6 months. AHD, pain-free ROM, and full ROM were measured at baseline and at week 6. The effects of KT were assessed using a nonparametric analysis for longitudinal data. Results: No significant group × time interactions (0.112 ≤ P ≤ 0.726) were found for all outcomes. Time effects were observed as both groups showed significant improvements for all studied outcomes (DASH, BPI, and WORC, p < 0.0001; AHD, p = 0.017; pain-free ROM, p < 0.0001; and full ROM abduction, p ≤ 0.0001). Conclusion: Whereas symptoms, functional limitations, ROM, and AHD improved in both groups, the addition of KT did not lead to superior outcomes compared with exercise-based treatment alone, in the mid and long term, for individuals with RCRSP. Clinical Relevance: Clinicians should not expect supplementary mid- or long-term gains with KT to reduce pain, improve shoulder function and ROM, or increase AHD if a rehabilitation program focusing on shoulder neuromuscular control is concurrently provided as treatment for individuals with RCRSP.

Background/AimAnkle sprains are frequent musculoskeletal injuries that can lead to sensorimotor deficits provoking long-term instability at the ankle joint. A broad variety of clinical tests currently exist to assess sensorimotor processing, and are commonly clinically referred to as proprioceptive tests. However, there is a discrepancy in the use of the term proprioception when looking at the main outcome of these tests. As identifying specific deficits is important for motor recovery, it is critical for clinicians to select the most appropriate tests.MethodsA systematic review of four databases was performed to provide an up-to-date review of the psychometric properties of available tests referred to as proprioceptive tests. Seventy-nine articles on eight ankle proprioceptive tests were included and critically appraised. Data on validity, reliability and responsiveness were extracted from the included articles and synthesised. The tests reviewed were then divided into two categories based on their main outcome: motor control or somatosensation.ResultsStrong evidence showed that the Star Excursion Balance Test, a motor control test, is capable of differentiating between stable and unstable ankles. Moderate evidence suggests that somatosensation tests, such as Joint Position Sense, are also valid and reliable, but their responsiveness has yet to be evaluated.ConclusionsTogether, these findings indicate that the Star Excursion Balance Test can be used in the clinic to assess motor control based on its excellent psychometric properties. However, as ankle stability control involves complex sensorimotor interactions, care has to be taken regarding the use of this test as a specific tool for proprioception assessment.

Background Previous studies have assessed the effects of perturbation training on balance after stroke. However, the perturbations were either applied while standing or were small in amplitude during gait, which is not representative of the most common fall conditions. The perturbations were also combined with other challenges such as progressive increases in treadmill speed. Objective To determine the benefit of treadmill training with intense and unpredictable perturbations compared to treadmill walking-only training for dynamic balance and gait post-stroke. Methods Twenty-one individuals post-stroke with reduced dynamic balance abilities, with or without a history of fall and ability to walk on a treadmill without external support or a walking aid for at least 1 min were allocated to either an unpredictable gait perturbation (Perturb) group or a walking-only (NonPerturb) group through covariate adaptive randomization. Nine training sessions were conducted over 3 weeks. NonPerturb participants only walked on the treadmill but were offered perturbation training after the control intervention. Pre- and post-training evaluations included balance and gait abilities, maximal knee strength, balance confidence and community integration. Six-week phone follow-ups were conducted for balance confidence and community integration. Satisfaction with perturbation training was also assessed. Results With no baseline differences between groups (p > 0.075), perturbation training yielded large improvements in most variables in the Perturb (p .46) group (n = 10) and the NonPerturb (p ≤ .089, ES > .45) group (n = 7 post-crossing), except for maximal strength (p > .23) in the NonPerturb group. Walking-only training in the NonPerturb group (n = 8, pre-crossing) mostly had no effect (p > .292, ES p = .063, ES = .46). The effects of the gait training were still present on balance confidence and community integration at follow-up. Satisfaction with the training program was high. Conclusion Intense and unpredictable gait perturbations have the potential to be an efficient component of training to improve balance abilities and community integration in individuals with chronic stroke. Retrospective registration: ClinicalTrials.gov. March 18th, 2020. Identifier: NCT04314830.

International audience; Inertial measurement units (IMUs) have been increasingly popular in rehabilitation research. However, despite their accessibility and potential advantages, their uptake and acceptance by health professionals remain a big challenge. The development of an IMU-based clinical tool must bring together engineers, researchers and clinicians. This study is part of a developmental process with the investigation of clinicians’ perspectives about IMUs. Clinicians from four rehabilitation centers were invited to a 30-minute presentation on IMUs. Then, two one-hour focus groups were conducted with volunteer clinicians in each rehabilitation center on: 1) IMUs and their clinical usefulness, and 2) IMUs data analysis and visualization interface. Fifteen clinicians took part in the first focus groups. They expressed their thoughts on: 1) categories of variables that would be useful to measure with IMUs in clinical practice, and 2) desired characteristics of the IMUs. Twenty-three clinicians participated to the second focus groups, discussing: 1) functionalities, 2) display options, 3) clinical data reported and associated information, and 4) data collection duration. Potential influence of IMUs on clinical practice and added value were discussed in both focus groups. Clinicians expressed positive opinions about the use of IMUs, but their expectations were high before considering using IMUs in their practice.

International audience; Temporal predictability and intensity of an impending nociceptive input both shape pain experience and modulate laser-evoked potentials (LEPs) amplitude. However, it remains unclear whether and how these two factors could influence pain-induced corticospinal excitability modulation. The current study investigated the influence of nociceptive stimulation intensity and temporal predictability on motor-evoked potentials (MEPs) modulation, in parallel to their effect on pain perception and LEPs amplitude. Twenty participants completed electroencephalographic and transcranial magnetic stimulation experiments during which two laser nociceptive stimulation intensities (high and low) were either unpredictably delivered (random delay) or preceded by a fixed-timing cue (fixed delay). The amplitude of the conditioned MEPs was significantly reduced only for the high nociceptive stimulation and was not affected by the temporal predictability of pain (despite the fact that temporal predictability modulated the amplitude of P2 LEP component amplitude). However, a posteriori analyses based on patterns of pain-induced MEPs modulation revealed that participants in which nociceptive stimulation resulted in an increase in corticospinal excitability were more affected by the predictability of pain (i.e. increasing corticospinal excitability even more when pain occurrence was predictable), regardless of the nociceptive stimulation intensity; whereas participants in which nociceptive stimulation resulted in a decrease in corticospinal excitability were sensitive to the intensity of the stimulation but not its predictability. These results suggest a potential influence of cognitive factors such as temporal predictability on the response of the motor system in the presence of pain for some participants, contributing to explain, at least in part, the high variability highlighted in a number of previous studies.

Inertial measurement units have recently shown great potential for the accurate measurement of joint angle movements in replacement of motion capture systems. In the race towards long duration tracking, inertial measurement units increasingly aim to ensure portability and long battery life, allowing improved ecological studies. Their main advantage over laboratory grade equipment is their usability in a wider range of environment for greater ecological value. For accurate and useful measurements, these types of sensors require a robust orientation estimation that remains accurate over long periods of time. To this end, we developed the Allumo software for the preprocessing and calibration of the orientation estimate of triaxial accelerometers. This software has an automatic orientation calibration procedure, an automatic erroneous orientation-estimate detection and useful visualization to help process long and short measurement periods. These automatic procedures are detailed in this paper, and two case studies are presented to showcase the usefulness of the software. The Allumo software is open-source and available online.

Introduction Proprioception is known to be affected after a spinal cord injury (SCI). However, it is currently assessed during simple tasks that do not reflect activities of daily living. To better understand how proprioception affects movement, assessing it during a functional sensorimotor task such as walking is therefore of primary importance. Therefore, the objectives of this study were as follows: (a) measure the protocol reliability of a new robotic test in nondisabled controls; (b) evaluate the effect nonlesion‐related factors such as sex, age, pain, and gait speed on ankle proprioception; and (c) assess ankle proprioception during walking in individuals with SCI. Methods In the current study, ankle proprioception was assessed during gait in individuals with an incomplete spinal cord injury (iSCI; n = 15) using an electrohydraulic robotized ankle–foot orthosis (rAFO). Ankle proprioceptive threshold was quantified as the participants’ ability to detect torque perturbations of varied amplitude applied during swing by the rAFO. In addition, test–retest reliability and the potential effect of nonlesion‐related factors (sex, age, pain, and gait speed) were evaluated in nondisabled (ND; n = 65) participants. Results During gait, individuals with iSCI had a 53% poorer proprioceptive threshold than ND controls (p, Ankle proprioceptive threshold assessment during gait using an electrohydraulic ankle foot orthosis is a reliable test. Gait proprioceptive threshold is affected in individuals with an incomplete spinal cord injury, in a manner that is not related to pain, gait speed, age or sex differences. Gait speed affects ankle proprioceptive threshold during gait, while age, sex and pain have no effect.

To identify predictors of outcome to a rehabilitation program focused on education and management of training loads in runners with patellofemoral pain (PFP).Secondary analyses of a randomized clinical trial.Fifty-eight runners with PFP (62% female, aged 31.2±6.6years, running 20.3±5.6km/week) were included in analyses. Following baseline collection of demographics, anthropometry, symptomatology, isometric strength, running mechanics and radiological data, runners were randomized to one of the three 8-week intervention program: (1) Education on symptoms management and training modifications; (2) Education+Exercise program; (3) Education+Gait retraining. Clinical success was defined as an increase ≥13.6% on the Knee Outcome Survey - Activities of Daily Living Scale (KOS-ADLS) at 3 months following program completion. Potential predictors were entered into logistic regression analyses.Forty-five runners (78%) were categorized as Success. Together, KOS-ADLS score (70%), knee extension isometric strength (70% bodyweight), presence of patellar tendinopathy (Grade0) and level of usual pain (2/10) at baseline predicted treatment outcome with 87.9% accuracy. The model provided sensitivity of 0.93 (95% C.I. 0.82-0.98), specificity of 0.69 (95% C.I. 0.42-0.87), positive likelihood ratio of 3.0 (95% C.I. 1.3-6.9), and negative likelihood ratio of 0.1 (95% C.I. 0-0.3). The best individual predictors were KOS-ADLS score and knee extension strength.The combination of KOS-ADLS, knee extensors strength, patellar tendon integrity and usual pain best predicted clinical outcome of runners with PFP following an intervention that had a common education component. Further testing is needed before a clinical prediction rule can be recommended to clinicians.

To compare hip kinematics during two functional tasks in females with and without patellofemoral pain (PFP), and to determine if hip kinematics and, symptoms and functional limitations were improved after a rehabilitation program.Cross sectional and longitudinal.Sixteen females with and 15 without PFP.Laboratory and physical therapy clinic.Hip adduction (HADD) and medial rotation (HMR) peak angles, time integrals and inter-movement variability during step-down and vertical drop jump, symptoms and functional limitations evaluated using the Activities of Daily Living Scale of the Knee Outcome Survey (KOS-ADLS).At baseline, no significant differences were found in step-down and vertical drop jump between PFP and controls. Following rehabilitation, significant improvements were reported in KOS-ADLS (p 0.001). There was a significant decrease in HADD and HMR variability (p 0.05), a trend for decreased peak HMR (p = 0.06) during step-down, and a significant decrease in HADD variability (p 0.05) during vertical drop jump. These kinematic changes did not correlate with changes in KOS-ADLS (all p 0.05).Females with and without PFP demonstrated no hip kinematic differences during functional tasks. A rehabilitation program improved symptoms and functional status, and modified hip kinematics in females with PFP; however these changes were not correlated.

KEY POINTS Experimental pain or its anticipation influence motor preparation processes as well as upcoming movement execution, but the underlying physiological mechanisms remain unknown. Our results showed that movement-related pain modulates corticospinal excitability during motor preparation. In accordance with the pain adaptation theory, corticospinal excitability was higher when the muscle has an antagonist (vs. an agonist) role for the upcoming movement associated with pain. Anticipation of movement-related pain also affects motor initiation and execution, with slower movement initiation (longer reaction times) and faster movement execution compared to movements that do not evoke pain. These results confirm the implementation of protective strategies during motor preparation known to be relevant for acute pain, but which may potentially have detrimental long-term consequences and lead to the development of chronic pain. ABSTRACT When a movement repeatedly generates pain, we anticipate movement-related pain and establish self-protective strategies during motor preparation, but the underlying mechanisms remains poorly understood. The current study investigated the effect of movement-related pain anticipation on the modulation of behaviour and corticospinal excitability during the preparation of arm movements. Participants completed an instructed-delay reaction-time (RT) task consisting of elbow flexions and extensions instructed by visual cues. Nociceptive laser stimulations (unconditioned stimuli) were applied to the lateral epicondyle during movement execution in a specific direction (CS+) but not in the other (CS-), depending on experimental group. During motor preparation, transcranial magnetic stimulation was used to measure corticospinal excitability in the biceps brachii (BB). RT and peak end-point velocity were also measured. Neurophysiological results revealed an opposite modulation of corticospinal excitability in BB depending on whether it plays an agonist (i.e. flexion) or antagonist (i.e. extension) role for the CS+ movements (P

This study examined the geometrical relationships between the feet, pelvis and an environmental obstruction when crossing an obstacle with unexpected changes to its position. Nine healthy young adults stepped over an obstacle 19 cm high with their right leg leading. The obstacle could be static or advanced at either lead (early detection) or trail (late detection) foot contact prior to clearance to force an adaptive reorganization of body-foot geometry and foot proximity to the obstacle. Stride length, minimum foot clearance over the obstacle, and foot-obstacle horizontal proximity before and after clearance were measured along with the relative position of the pelvis to each foot at eight points (four for each foot) during approach and clearance: heel contacts before and after crossing the obstacle, maximum foot heights and foot clearances. With early obstacle movement, trail limb stride length before crossing was lengthened, but foot proximity was still far from the final obstacle position. Clearance was less affected for the trail foot as compared to the lead foot. Proximity of the lead limb following clearance was the same for both early and late perturbations and closer than for the static obstacle condition. For relative body-foot positioning, significant differences were found only in the anterior-posterior direction. Following obstacle displacement, body-foot geometry was initially adapted, but then re-established to static obstacle values with an apparent focus on a balance geometry with the forward placed foot establishing new contact. These findings support an overall balance geometry that can be temporarily adjusted and coordinated with foot proximity to the obstruction to maintain continual gait and safe clearance.