Development of a Comprehensive Outcome Measure for Motor Coordination; Step 1: Three-Phase Content Validity Process

BACKGROUND

Motor coordination, the ability to produce context-dependent organized movements in spatial and temporal domains, is impaired after neurological injuries. Outcome measures assessing coordination mostly quantify endpoint performance variables (ie, temporal qualities of whole arm movement) but not movement quality (ie, trunk and arm joint displacements).

OBJECTIVE

To develop an outcome measure to assess coordination of multiple body segments at both endpoint trajectory and movement quality levels, based on observational kinematics, in adults with neurological injuries.

METHODS

A 3-phase study was used to develop the Comprehensive Coordination Scale (CCS): instrument development, Delphi process, and focus group meeting. The CCS was constructed from common tests used in clinical practice and research. Rating scales for different behavioral elements were developed to guide analysis. For content validation, 8 experts (ie, neurological clinicians/researchers) answered questionnaires about relevance, comprehension, and feasibility of each test and rating scale. A focus group conducted with 6 of 8 experts obtained consensus on rating scale and instruction wording, and identified gaps. Three additional experts reviewed the revised CCS content to obtain a final version.

RESULTS

Experts identified a gap regarding assessment of hand/finger coordination. The CCS final version is composed of 6 complementary tests of coordination: finger-to-nose, arm-trunk, finger, lower extremity, and 2- and 4-limb interlimb coordination. Constructs include spatial and temporal variables totaling 69 points. Higher scores indicate better performance.

CONCLUSIONS

The CCS may be an important, understandable and feasible outcome measure to assess spatial and temporal coordination. CCS measurement properties are presented in the companion article.

Improving body functions through participation in community activities among young people with physical disabilities

AIM

To examine the impact of engagement in a self-chosen community-based activity on three relevant body functions (motor, cognitive, and affective) as well as on the performance of the selected activity.

METHOD

An individual-based interrupted time series design with multiple baselines was used. Seven young people (four males, three females) aged 15 to 25 years (median 18y; interquartile range 17-20y) with physical disabilities participated in an 8-week community activity of choice (e.g. swimming, playing piano). Change in three relevant body functions, underpinning the specific chosen activity, including motor (e.g. Functional Reach Test, Trunk Impairment Scale, dynamometers), cognitive and affective (Behavior Assessment System for Children), as well as activity performance (Canadian Occupational Performance Measure) were measured repeatedly, providing individual outcome trajectories. Linear and mixed-effects models were used.

RESULTS

Significant improvements in at least one aspect of motor function (6 out of 6), cognition (3 out of 3), affect (5 out of 7), and performance (7 out of 7) were observed. Specifically, the intervention had a moderate to large effect on hyperactivity (1.45, 95% confidence interval [CI] 1.0-1.9) with a smaller effect on anxiety (0.21, 95% CI 0.10-0.32) and inadequacy (0.21, 95% CI 0.02-0.39). Concurrently, a notable effect size for activity performance (4.61, 95% CI 0.76-8.46) was observed. Average change across motor outcomes was substantial (3.7 SDs from baseline), yet non-significant.

INTERPERTATION

Findings provide initial evidence of the benefits resulting from participation-based interventions, emphasizing the merit of meaningful 'real-life' young people-engaging therapy.

WHAT THIS PAPER ADDS

Participation-based interventions can impact body-function level outcomes. Significant improvements in the performance of chosen activities were observed. Significant improvements were also seen in cognitive and affective body functions. Improvements in motor-related outcomes were substantial but not statistically significant.

Stability of reaching during standing in stroke

Reaching from standing requires simultaneous adjustments of focal and postural task elements. We investigated the ability of people with stroke to stabilize the endpoint trajectory while maintaining balance during standing reaches. Nineteen stroke and 11 age-equivalent healthy subjects reached toward a target (n = 30 trials) located beyond arm length from standing. Endpoint and center-of-mass (COM) trajectories were analyzed using the uncontrolled manifold (UCM) approach, with segment angles as elemental variables. A synergy index (SI) represented the normalized difference between segment angle combinations, leading to endpoint or COM trajectory stabilization (V_UCM) and lack of stabilization (in an orthogonal space; V_ORT). A higher SI reflects greater stability. In both groups, the endpoint SI (SI_END) decreased in parallel with endpoint velocity and returned close to baseline at the end of the movement. The range of SI_END was significantly greater in stroke (median: 0.87; QR:0.54) compared with healthy subjects (median: 0.58; QR: 0.33; P = 0.009). In both groups, the lowest SI_END occurred at the endpoint peak velocity, whereas the minimal SI_END of the stroke group (median: 0.51; QR:0.41) was lower than the healthy group (median: 0.25; QR: 0.50; P = 0.033). The COM SI (SI_COM) remained stable in both groups (~0.8). The maintenance of a high SI_COM despite a large reduction of SI_END in stroke subjects suggests that kinematic redundancy was effectively used to stabilize the COM position, but less so for endpoint position stabilization. Both focal and postural task elements should be considered when analyzing whole body reaching deficits in patients with stroke.NEW & NOTEWORTHY Reaching from standing requires simultaneous adjustments of endpoint and center-of-mass (COM) positions. We used uncontrolled manifold analysis to investigate the impact of stroke on the ability to use kinematic redundancy in this task. Our results showed that COM position was stabilized, whereas endpoint trajectory was more variable in stroke than healthy subjects. Enhancing the capacity to meet multiple task goals may be beneficial for motor recovery after stroke.

Kinematic Validity of Reaching in a 2D Virtual Environment for Arm Rehabilitation After Stroke

Increasing evidence supports the use of virtual reality for stroke rehabilitation. However, movement performance and quality may be diminished by the attributes of the virtual environment (VE), which may be detrimental to motor relearning. Our aim was to determine whether reach-to-grasp movements made in a low-cost 2DVE were kinematically similar to those made in a comparable physical environment (PE) in healthy subjects and subjects with stroke. Subjects (healthy = 15, stroke = 22) made unilateral and bilateral reach-to-grasp movements in a 2DVE and a similar PE. Arm and trunk kinematics were recorded with an optoelectronic measurement system (23 markers; 120 Hz). Temporal and spatial characteristics of the endpoint trajectory, arm and trunk movement patterns were compared between environments and groups. In each group, hand positioning at object contact time and trunk displacement were unaffected by the environment. Compared to PE, in VE, unilateral movements were less smooth and time to peak velocity was prolonged. In healthy subjects, bilateral movements were simultaneous and symmetrical in both environments. In subjects with stroke, movements were less symmetrical in VE. Aside from differences in endpoint displacement between environments, movement quality variables were unaffected by the 2DVE. Thus, using a low-cost 2DVE may be a valid approach for sensorimotor rehabilitation following stroke.

Motor-Equivalent Intersegmental Coordination Is Impaired in Chronic Stroke

Background. Kinematic abundance permits using different movement patterns for task completion. Individuals poststroke may take advantage of abundance by using compensatory trunk displacement to overcome upper limb (UL) movement deficits. However, movement adaptation in tasks requiring specific intersegment coordination may remain limited. Objective. We tested movement adaptation in both arms of individuals with chronic stroke (n = 16) and nondominant arms of controls (n = 12) using 2 no-vision reaching tasks involving trunk movement (40 trials/arm). Methods. In the "stationary hand task" (SHT), subjects maintained the hand motionless over a target while leaning the trunk forward. In the "reaching hand task" (RHT), subjects reached to the target while leaning forward. For both tasks, trunk movement was unexpectedly blocked in 40% of trials to assess the influence of trunk movement on adaptive arm positioning or reaching. UL sensorimotor impairment, activity, and sitting balance were assessed in the stroke group. The primary outcome measure for SHT was gain (g), defined as the extent to which trunk displacement contributing to hand motion was offset by appropriate changes in UL movements (g = 1: complete compensation) and endpoint deviation for RHT. Results. Individuals poststroke had lower gains and greater endpoint deviation using the more-affected compared with less-affected UL and controls. Those with less sensorimotor impairment, greater activity levels, and better sitting balance had higher gains and smaller endpoint deviations. Lower gains were associated with diminished UL adaptability. Conclusions. Tests of condition-specific adaptability of interjoint coordination may be used to measure UL adaptability and changes in adaptability with treatment.

Development of vertical and forward jumping skills in typically developing children in the context of referent control of motor actions

The empirically based referent control theory of motor actions provides a new framework for understanding locomotor maturation. Mature movement patterns of referent control are characterized by periods of minimization of activity across multiple muscles (global electromyographic [EMG] minima) resulting from transient matching between actual and referent body configurations. We identified whether locomotor maturation in young children was associated with (a) development of referent control and (b) children's frequency of participation in everyday activities evaluated by parents. Kinematics and EMG activity were recorded from typically developing children (n = 15, 3-5 years) and young adults (n = 10, 18-25 years) while walking, vertical or forward jumping. Presence and location of global EMG minima in movement cycles, slopes of ankle vertical/sagittal displacements, and shoulder displacement ratios were evaluated. Children had fewer global EMG minima compared to adults during specific phases of vertical and forward jumps. Ankle displacement profiles for walking and jumping forward were related to each other in adults, whereas those for walking and vertical jumping were related in children. Higher frequency of participation was significantly correlated with more mature jumping patterns in children. A decrease in the number of global EMG minima and changes in ankle movement patterns could be indicators of locomotor immaturity in typically developing children.

Relationship Between Spasticity and Upper-Limb Movement Disorders in Individuals With Subacute Stroke Using Stochastic Spatiotemporal Modeling

BACKGROUND

Spasticity is common in patients with stroke, yet current quantification methods are insufficient for determining the relationship between spasticity and voluntary movement deficits. This is partly a result of the effects of spasticity on spatiotemporal characteristics of movement and the variability of voluntary movement. These can be captured by Gaussian mixture models (GMMs).

OBJECTIVES

To determine the influence of spasticity on upper-limb voluntary motion, as assessed by the bidirectional Kullback-Liebler divergence (BKLD) between motion GMMs.

METHODS

A total of 16 individuals with subacute stroke and 13 healthy aged-equivalent controls reached to grasp 4 targets (near-center, contralateral, far-center, and ipsilateral). Two-dimensional GMMs (angle and time) were estimated for elbow extension motion. BKLD was computed for each individual and target, within the control group and between the control and stroke groups. Movement time, final elbow angle, average elbow velocity, and velocity smoothness were computed.

RESULTS

Between-group BKLDs were much larger than within control-group BKLDs. Between-group BKLDs for the near-center target were lower than those for the far-center and contralateral targets, but similar to that for the ipsilateral target. For those with stroke, the final angle was lower for the near-center target, and the average velocity was higher. Velocity smoothness was lower for the near-center than for the ipsilateral target. Elbow flexor and extensor passive muscle resistance (Modified Ashworth Scale) strongly explained BKLD values.

CONCLUSIONS

Results support the view that individuals with poststroke spasticity have a velocity-dependent reduction in active elbow joint range and that BKLD can be used as an objective measure of the effects of spasticity on reaching kinematics.

Standardized Measurement of Quality of Upper Limb Movement After Stroke: Consensus-Based Core Recommendations From the Second Stroke Recovery and Rehabilitation Roundtable

The second Stroke Recovery and Rehabilitation Roundtable "metrics" task force developed consensus around the recognized need to add kinematic and kinetic movement quantification to its core recommendations for standardized measurements of sensorimotor recovery in stroke trials. Specifically, we focused on measurement of the quality of upper limb movement. We agreed that the recommended protocols for measurement should be conceptually rigorous, reliable, valid and responsive to change. The recommended measurement protocols include four performance assays (i.e. 2D planar reaching, finger individuation, grip strength, and precision grip at body function level) and one functional task (3D drinking task at activity level) that address body function and activity respectively. This document describes the criteria for assessment and makes recommendations about the type of technology that should be used for reliable and valid movement capture. Standardization of kinematic measurement protocols will allow pooling of participant data across sites, thereby increasing sample size aiding meta-analyses of published trials, more detailed exploration of recovery profiles, the generation of new research questions with testable hypotheses, and development of new treatment approaches focused on impairment. We urge the clinical and research community to consider adopting these recommendations.

Standardized measurement of quality of upper limb movement after stroke: Consensus-based core recommendations from the Second Stroke Recovery and Rehabilitation Roundtable

The second Stroke Recovery and Rehabilitation Roundtable “metrics” task force developed consensus around the recognized need to add kinematic and kinetic movement quantification to its core recommendations for standardized measurements of sensorimotor recovery in stroke trials. Specifically, we focused on measurement of the quality of upper limb movement. We agreed that the recommended protocols for measurement should be conceptually rigorous, reliable, valid and responsive to change. The recommended measurement protocols include four performance assays (i.e. 2D planar reaching, finger individuation, grip strength, and precision grip at body function level) and one functional task (3D drinking task at activity level) that address body function and activity respectively. This document describes the criteria for assessment and makes recommendations about the type of technology that should be used for reliable and valid movement capture. Standardization of kinematic measurement protocols will allow pooling of participant data across sites, thereby increasing sample size aiding meta-analyses of published trials, more detailed exploration of recovery profiles, the generation of new research questions with testable hypotheses, and development of new treatment approaches focused on impairment. We urge the clinical and research community to consider adopting these recommendations.

Relationship Between Clinical Measures of Upper Limb Movement Quality and Activity Poststroke

Background. Understanding the relationship between movement quality (impairment) and performance (activity) in poststroke patients is important for rehabilitation intervention studies. This has led to an interest in kinematic characterization of upper limb motor impairment. Since instrumented motion analysis is not readily clinically available, observational kinematics may be a viable alternative. Objective. To determine if upper limb movement quality during a reach-to-grasp task identified by observation could be used to describe the relationship between motor impairments and the time to perform functional tasks. Methods. Cross-sectional, secondary analysis of baseline data from 141 participants with stroke, age 18 to 85 years, who participated in a multicenter randomized controlled trial. Clinical assessment of movement quality using the Reaching Performance Scale for Stroke (RPSS-Close and Far targets) and of performance (activity) from the Wolf Motor Function Test (WMFT-7 items) was assessed. The degree to which RPSS component scores explained scores on WMFT items was determined by multivariable regression. Results. Clinically significant decreases (>2 seconds) in performance time for some of the more complex WMFT tasks involving prehension were predicted from RPSS-Close and Far target components. Trunk compensatory movements did not predict either increases or decreases in performance time for the WMFT tasks evaluated. Overall, the strength of the regression models was low. Conclusions. In lieu of kinematic analysis, observational clinical movement analysis may be a valid and accessible method to determine relationships between motor impairment, compensations and upper limb function in poststroke patients. Specific relationships are unlikely to generalize to all tasks due to kinematic redundancy and task specificity.

Electromyogram-Related Neuromuscular Electrical Stimulation for Restoring Wrist and Hand Movement in Poststroke Hemiplegia: A Systematic Review and Meta-Analysis

Background. Clinical trials have demonstrated some benefits of electromyogram-triggered/controlled neuromuscular electrical stimulation (EMG-NMES) on motor recovery of upper limb (UL) function in patients with stroke. However, EMG-NMES use in clinical practice is limited due to a lack of evidence supporting its effectiveness. Objective. To perform a systematic review and meta-analysis to determine the effects of EMG-NMES on stroke UL recovery based on each of the International Classification of Functioning, Disability, and Health (ICF) domains. Methods. Database searches identified clinical trials comparing the effect of EMG-NMES versus no treatment or another treatment on stroke upper extremity motor recovery. A meta-analysis was done for outcomes at each ICF domain (Body Structure and Function, Activity and Participation) at posttest (short-term) and follow-up periods. Subgroup analyses were conducted based on stroke chronicity (acute/subacute, chronic phases). Sensitivity analysis was done by removing studies rated as poor or fair quality (PEDro score <6). Results. Twenty-six studies (782 patients) met the inclusion criteria. Fifty percent of them were considered to be of high quality. The meta-analysis showed that EMG-NMES has a robust short-term effect on improving UL motor impairment in the Body Structure and Function domain. No evidence was found in favor of EMG-NMES for the Activity and Participation domain. EMG-NMES had a stronger effect for each ICF domain in chronic (≥3 months) compared to acute/subacute phases. Conclusion. EMG-NMES is effective in the short term in improving UL impairment in individuals with chronic stroke.

Vestibular and corticospinal control of human body orientation in the gravitational field

Body orientation with respect to the direction of gravity changes when we lean forward from upright standing. We tested the hypothesis that during upright standing, the nervous system specifies the referent body orientation that defines spatial thresholds for activation of multiple muscles across the body. To intentionally lean the body forward, the system is postulated to transfer balance and stability to the leaned position by monotonically tilting the referent orientation, thus increasing the activation thresholds of ankle extensors and decreasing their activity. Consequently, the unbalanced gravitational torque would start to lean the body forward. With restretching, ankle extensors would be reactivated and generate increasing electromyographic (EMG) activity until the enhanced gravitational torque would be balanced at a new posture. As predicted, vestibular influences on motoneurons of ankle extensors evaluated by galvanic vestibular stimulation were smaller in the leaned compared with the upright position, despite higher tonic EMG activity. Defacilitation of vestibular influences was also observed during forward leaning when the EMG levels in the upright and leaned position were equalized by compensating the gravitational torque with a load. The vestibular system is involved in the active control of body orientation without directly specifying the motor outcome. Corticospinal influences originating from the primary motor cortex evaluated by transcranial magnetic stimulation remained similar at the two body postures. Thus, in contrast to the vestibular system, the corticospinal system maintains a similar descending facilitation of motoneurons of leg muscles at different body orientations. The study advances the understanding of how body orientation is controlled. NEW & NOTEWORTHY The brain changes the referent body orientation with respect to gravity to lean the body forward. Physiologically, this is achieved by shifts in spatial thresholds for activation of ankle muscles, which involves the vestibular system. Results advance the understanding of how the brain controls body orientation in the gravitational field. The study also extends previous evidence of empirical control of motor function, i.e., without the reliance on model-based computations and direct specification of motor outcome.

Validation of reaching in a virtual environment in typically developing children and children with mild unilateral cerebral palsy

AIM

To compare three reaching movements made in two planes between a low-cost, game-based virtual reality and a matched physical environment in typically developing children and children with cerebral palsy (CP). To determine if differences in kinematics are related to sensory deficits.

METHOD

An observational study in which 27 children (typically developing, n=17, mean age 13y, [SD] 2y 2mo, range 9y 3mo-17y 2mo; CP, n=10, mean age 13y 8mo, [SD] 1y 8mo, range 11y 1mo-17y 1mo, Manual Ability Classification System levels I-II) performed 15 trials of three gestures in each of a virtual reality and a matched physical environment. Upper-limb and trunk kinematics were recorded using an electromagnetic system (G4, Polhemus, six markers, 120Hz).

RESULTS

Compared to the physical environment, movements in virtual reality made by typically developing children were slower (p=0.002), and involved less trunk flexion (p=0.002) and rotation (p=0.026). Children with CP had more curved trajectories (p=0.005) and used less trunk flexion (p=0.003) and rotation (p=0.005). Elbow and shoulder kinematics differed from 2.8% to 155.4% between environments in both groups. Between groups, there were small, clinically insignificant differences with only the vertical gesture being longer in typically developing children. Children with CP who had greater tactile impairment used more trunk displacement.

INTERPRETATION

Clinicians and researchers need to be aware of differences in movement variables when setting goals or designing protocols for improving reaching in children with CP using low-cost, game-based virtual reality systems.

WHAT THIS PAPER ADDS

Upper-limb kinematics differed in each group when reaching in physical versus virtual environments. There were small differences in movements made by children with mild unilateral cerebral palsy (CP) compared to typically developing children. Differences in reaching kinematics should be considered when goal setting using virtual reality interventions for children with mild unilateral CP.

Feasibility of incorporating functionally relevant virtual rehabilitation in sub-acute stroke care: perception of patients and clinicians

PURPOSE

To determine user satisfaction and safety of incorporating a low-cost virtual rehabilitation intervention as an adjunctive therapeutic option for cognitive-motor upper limb rehabilitation in individuals with sub-acute stroke.

METHODS

A low-cost upper limb virtual rehabilitation application incorporating realistic functionally-relevant unimanual and bimanual tasks, specifically designed for cognitive-motor rehabilitation was developed for patients with sub-acute stroke. Clinicians and individuals with stroke interacted with the intervention for 15-20 or 20-45 minutes, respectively. The study had a mixed-methods convergent parallel design that included a focus group interview with clinicians working in a stroke program and semi-structured interviews and standardized assessments (Borg Perceived Exertion Scale, Short Feedback Questionnaire) for participants with sub-acute stroke undergoing rehabilitation. The occurrence of adverse events was also noted.

RESULTS

Three main themes emerged from the clinician focus group and patient interviews: Perceived usefulness in rehabilitation, satisfaction with the virtual reality intervention and aspects to improve. All clinicians and the majority of participants with stroke were highly satisfied with the intervention and perceived its usefulness to decrease arm motor impairment during functional tasks. No participants experienced major adverse events.

CONCLUSIONS

Incorporation of this type of functional activity game-based virtual reality intervention in the sub-acute phase of rehabilitation represents a way to transfer skills learned early in the clinical setting to real world situations. This type of intervention may lead to better integration of the upper limb into everyday activities. Implications for Rehabilitation • Use of a cognitive-motor low-cost virtual reality intervention designed to remediate arm motor impairments in sub-acute stroke is feasible, safe and perceived as useful by therapists and patients for stroke rehabilitation.    • Input from end-users (therapists and individuals with stroke) is critical for the development and implementation of a virtual reality intervention.

Active Video Gaming for Children with Cerebral Palsy: Does a Clinic-Based Virtual Reality Component Offer an Additive Benefit? A Pilot Study

AIMS

To compare changes in gross motor skills and functional mobility between ambulatory children with cerebral palsy who underwent a 1-week clinic-based virtual reality intervention (VR) followed by a 6-week, therapist-monitored home active video gaming (AVG) program and children who completed only the 6-week home AVG program.

METHODS

Pilot non-randomized controlled trial. Five children received 1 hour of VR training for 5 days followed by a 6-week home AVG program, supervised online by a physical therapist. Six children completed only the 6-week home AVG program. The Gross Motor Function Measure Challenge Module (GMFM-CM) and Six Minute Walk Test (6MWT) evaluated change.

RESULTS

There were no significant differences between groups. The home AVG-only group demonstrated a statistically and clinically significant improvement in GMFM-CM scores following the 6-week AVG intervention (median difference 4.5 points, interquartile range [IQR] 4.75, p = 0.042). The VR + AVG group demonstrated a statistically and clinically significant decrease in 6MWT distance following the intervention (median decrease 68.2 m, IQR 39.7 m, p = 0.043). All 6MWT scores returned to baseline at 2 months post-intervention.

CONCLUSION

Neither intervention improved outcomes in this small sample. Online mechanisms to support therapist-child communication for exercise progression were insufficient to individualize exercise challenge.

Extrinsic feedback and upper limb motor skill learning in typically-developing children and children with cerebral palsy: Review

BACKGROUND

Improvment of upper limb motor skills occurs through motor learning that can be enhanced by providing extrinsic feedback. Different types and frequencies of feedback are discussed but specific guidelines for use of feedback for motor learning in typically-developing (TD) children and children with Cerebral Palsy (CP) are not available.

OBJECTIVE

Identify the most effective modalities and frequencies of feedback for improving upper limb motor skills in TD children and children with CP.

METHODS

Ovid MEDLINE, Cochrane, PEDro and PubMed-NCBI were searched from 1950 to December 2015 to identify English-language articles addressing the role of extrinsic feedback on upper limb motor learning in TD children and children with CP. Nine studies were selected with a total of 243 TD children and 102 children with CP. Study quality was evaluated using the Downs and Black scale and levels of evidence were determined with Sackett's quality ratings.

RESULTS

There was a lack of consistency in the modalities and frequencies of feedback delivery used to improve motor learning in TD children and in children with CP. Moreover, the complexity of the task to be learned influenced the degree of motor learning achieved.

CONCLUSION

A better understanding of the influence of feedback on motor learning is needed to optimize motor skill acquisition in children with CP.

Personalized upper limb training combined with anodal-tDCS for sensorimotor recovery in spastic hemiparesis: study protocol for a randomized controlled trial

Background

Recovery of voluntary movement is a main rehabilitation goal. Efforts to identify effective upper limb (UL) interventions after stroke have been unsatisfactory. This study includes personalized impairment-based UL reaching training in virtual reality (VR) combined with non-invasive brain stimulation to enhance motor learning. The approach is guided by limiting reaching training to the angular zone in which active control is preserved (“active control zone”) after identification of a “spasticity zone”. Anodal transcranial direct current stimulation (a-tDCS) is used to facilitate activation of the affected hemisphere and enhance inter-hemispheric balance. The purpose of the study is to investigate the effectiveness of personalized reaching training, with and without a-tDCS, to increase the range of active elbow control and improve UL function.

Methods

This single-blind randomized controlled trial will take place at four academic rehabilitation centers in Canada, India and Israel. The intervention involves 10 days of personalized VR reaching training with both groups receiving the same intensity of treatment. Participants with sub-acute stroke aged 25 to 80 years with elbow spasticity will be randomized to one of three groups: personalized training (reaching within individually determined active control zones) with a-tDCS (group 1) or sham-tDCS (group 2), or non-personalized training (reaching regardless of active control zones) with a-tDCS (group 3). A baseline assessment will be performed at randomization and two follow-up assessments will occur at the end of the intervention and at 1 month post intervention. Main outcomes are elbow-flexor spatial threshold and ratio of spasticity zone to full elbow-extension range. Secondary outcomes include the Modified Ashworth Scale, Fugl-Meyer Assessment, Streamlined Wolf Motor Function Test and UL kinematics during a standardized reach-to-grasp task.

Discussion

This study will provide evidence on the effectiveness of personalized treatment on spasticity and UL motor ability and feasibility of using low-cost interventions in low-to-middle-income countries.

Trial registration

ClinicalTrials.gov, ID: NCT02725853. Initially registered on 12 January 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2377-6) contains supplementary material, which is available to authorized users.

Upper Limb Coordination in Individuals With Stroke: Poorly Defined and Poorly Quantified

Background. The identification of deficits in interjoint coordination is important in order to better focus upper limb rehabilitative treatment after stroke. The majority of standardized clinical measures characterize endpoint performance, such as accuracy, speed, and smoothness, based on the assumption that endpoint performance reflects interjoint coordination, without measuring the underlying temporal and spatial sequences of joint recruitment directly. However, this assumption is questioned since improvements of endpoint performance can be achieved through different degrees of restitution or compensation of upper limb motor impairments based on the available kinematic redundancy of the system. Confusion about adequate measurement may stem from a lack a definition of interjoint coordination during reaching. Methods and Results. We suggest an operational definition of interjoint coordination during reaching as a goal-oriented process in which joint degrees of freedom are organized in both spatial and temporal domains such that the endpoint reaches a desired location in a context-dependent manner. Conclusions. In this point-of-view article, we consider how current approaches to laboratory and clinical measures of coordination comply with our definition. We propose future study directions and specific research strategies to develop clinical measures of interjoint coordination with better construct and content validity than those currently in use.

Spasticity may obscure motor learning ability after stroke

Previous motor learning studies based on adapting movements of the hemiparetic arm in stroke subjects have not accounted for spasticity occurring in specific joint ranges (spasticity zones), resulting in equivocal conclusions about learning capacity. We compared the ability of participants with stroke to rapidly adapt elbow extension movements to changing external load conditions outside and inside spasticity zones. Participants with stroke ( n = 12, aged 57.8 ± 9.6 yr) and healthy age-matched controls ( n = 8, 63.5 ± 9.1 yr) made rapid 40°-50° horizontal elbow extension movements from an initial (3°) to a final (6°) target. Sixteen blocks (6-10 trials/block) consisting of alternating loaded (30% maximal voluntary contraction) and nonloaded trials were made in one (controls) or two sessions (stroke; 1 wk apart). For the stroke group, the tonic stretch reflex threshold angle at which elbow flexors began to be activated during passive elbow extension was used to identify the beginning of the spasticity zone. The task was repeated in joint ranges that did or did not include the spasticity zone. Error correction strategies were identified by the angular positions before correction and compared between groups and sessions. Changes in load condition from no load to load and vice versa resulted in undershoot and overshoot errors, respectively. Stroke subjects corrected errors in 1-4 trials compared with 1-2 trials in controls. When movements did not include the spasticity zone, there was an immediate decrease in the number of trials needed to restore accuracy, suggesting that the capacity to learn may be preserved after stroke but masked by the presence of spasticity. NEW & NOTEWORTHY When arm movements were made outside, instead of inside, the range affected by spasticity, there was an immediate decrease in the number of trials needed to restore accuracy in response to a change in the external load. This suggests that motor learning processes may be preserved in patients with stroke but masked by the presence of spasticity in specific joint ranges. This has important implications for designing rehabilitation interventions predicated on motor learning principles.