Adaptive control is reversed between hands after left hemisphere stroke and lost following right hemisphere stroke.

Human motor adaptability is of utmost utility after neurologic injury such as unilateral stroke. For successful adaptive control of movements, the nervous system must learn to correctly identify the source of a movement error and predictively compensate for this error. The current understanding is that in bimanual tasks, this process is flexible such that errors are assigned to, and compensated for, by the limb that is more likely to produce those errors. Here, we tested the flexibility of the error assignment process in right-handed chronic stroke survivors using a bimanual reaching task in which the hands jointly controlled a single cursor. We predicted that the nondominant left hand in neurotypical adults and the paretic hand in chronic stroke survivors will be more responsible for cursor errors and will compensate more within a trial and learn more from trial to trial. We found that in neurotypical adults, the nondominant left hand does compensate more than the right hand within a trial but learns less trial-to-trial. After a left hemisphere stroke, the paretic right hand compensates more than the nonparetic left hand within-trial but learns less trial-to-trial. After a right hemisphere stroke, the paretic left hand neither corrects more within-trial nor learns more trial-to-trial. Thus, adaptive control of visually guided bimanual reaching movements is reversed between hands after the left hemisphere stroke and lost following the right hemisphere stroke. These results indicate that responsibility assignment is not fully flexible but depends on a central mechanism that is lateralized to the right hemisphere.

A Novel, Wearable Inertial Measurement Unit for Stroke Survivors: Validity, Acceptability, and Usability.

OBJECTIVE: To establish the concurrent validity, acceptability, and sensor optimization of a consumer-grade, wearable, multi-sensor system to capture quantity and quality metrics of mobility and upper limb movements in stroke survivors. DESIGN: Single-session, cross-sectional. SETTING: Clinical research laboratory. PARTICIPANTS: Thirty chronic stroke survivors (age 57 (10) years; 33% female) with mild to severe motor impairments participated. INTERVENTIONS: Not Applicable. MAIN OUTCOME MEASURES: Participants donned 5 sensors and performed standardized assessments of mobility and upper limb (UL) movement. True/false, positive/negative time in active movement for the UL were calculated and compared to criterion-standards using an accuracy rate. Bland-Altman plots and linear regression models were used to establish concurrent validity of UL movement counts, step counts, and stance time symmetry of MiGo against established criterion-standard measures. Acceptability and sensor optimization were assessed through an end-user survey and decision matrix. RESULTS: Mobility metrics showed excellent association with criterion-standards for step counts (video: r=0.988, P<.001, IMU: r=0.921, P<.001) and stance-time symmetry (r=0.722, P<.001). In the UL, movement counts showed excellent to good agreement (paretic: r=0.849, P<.001, nonparetic: r=0.672, P<.001). Accuracy of active movement time was 85.2% (paretic) and 88.0% (nonparetic) UL. Most participants (63.3%) had difficulty donning/doffing the sensors. Acceptability was high (4.2/5). CONCLUSIONS: The sensors demonstrated excellent concurrent validity for mobility metrics and UL movements of stroke survivors. Acceptability of the system was high, but alternative wristbands should be considered.

Moderate-intensity cardiovascular exercise performed before motor practice attenuates offline implicit motor learning in stroke survivors but not age-matched neurotypical adults.

The acute impact of cardiovascular exercise on implicit motor learning of stroke survivors is still unknown. We investigated the effects of cardiovascular exercise on implicit motor learning of mild-moderately impaired chronic stroke survivors and neurotypical adults. We addressed whether exercise priming effects are time-dependent (e.g., exercise before or after practice) in the encoding (acquisition) and recall (retention) phases. Forty-five stroke survivors and 45 age-matched neurotypical adults were randomized into three sub-groups: BEFORE (exercise, then motor practice), AFTER (motor practice, then exercise), and No-EX (motor practice alone). All sub-groups practiced a serial reaction time task (five repeated and two pseudorandom sequences per day) on three consecutive days, followed 7 days later by a retention test (one repeated sequence). Exercise was performed on a stationary bike, (one 20-min bout per day) at 50% to 70% heart rate reserve. Implicit motor learning was measured as a difference score (repeated-pseudorandom sequence response time) during practice (acquisition) and recall (delayed retention). Separate analyses were performed on the stroke and neurotypical groups using linear mixed-effects models (participant ID was a random effect). There was no exercise-induced benefit on implicit motor learning for any sub-group. However, exercise performed before practice impaired encoding in neurotypical adults and attenuated retention performance of stroke survivors. There is no benefit to implicit motor learning of moderately intense cardiovascular exercise for stroke survivors or age-matched neurotypical adults, regardless of timing. Practice under a high arousal state and exercise-induced fatigue may have attenuated offline learning in stroke survivors.

Essential Role of Social Context and Self-Efficacy in Daily Paretic Arm/Hand Use After Stroke: An Ecological Momentary Assessment Study With Accelerometry.

OBJECTIVE: To determine the momentary effect of social-cognitive factors, in addition to motor capability, on post-stroke paretic arm/hand use in the natural environment. DESIGN: A 5-day observational study in which participants were sent 6 Ecological Momentary Assessment (EMA) prompts/day. SETTING: Participants' daily environment. PARTICIPANTS: Community-dwelling, chronic stroke survivors with right-dominant, mild-moderate upper extremity paresis (N=30). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Time duration of bimanual and unimanual paretic arm/hand use indexed by accelerometry; social-cognitive factors (social context, self-efficacy, mood) captured by EMA; motor capability of the paretic limb measured by Fugl-Meyer Upper Extremity Motor Assessment (FM). RESULTS: After accounting for participants' motor capability, we found that momentary social context (alone or not) and self-efficacy significantly predicted post-stroke paretic arm/hand use behavior in the natural environment. When participants were not alone, paretic arm/hand movement increased both with and without the less-paretic limb (bimanual and unimanual movements, P=.018 and P<.001, respectively). Importantly, participants were more likely to use their paretic arm/hand (unimanually) if they had greater self-efficacy for limb use (P=.042). EMA repeated-measures provide a real-time approach that captures the natural dynamic ebb and flow of social-cognitive factors and their effect on daily arm/hand use. We also observed that people with greater motor impairments (FM<50.6) increase unimanual paretic arm/hand movements when they are not alone, regardless of motor capability. CONCLUSIONS: In addition to motor capability, stroke survivors' momentary social context and self-efficacy play a role in paretic arm/hand use behavior. Our findings suggest the development of personalized rehabilitative interventions which target these factors to promote daily paretic arm/hand use. This study highlights the benefits of EMA to provide real-time information to unravel the complexities of the biopsychosocial (ie, motor capability and social-cognitive factors) interface in post-stroke upper extremity recovery.

Long-term forecasting of a motor outcome following rehabilitation in chronic stroke via a hierarchical bayesian dynamic model.

BACKGROUND: Given the heterogeneity of stroke, it is important to determine the best course of motor therapy for each patient, i.e., to personalize rehabilitation based on predictions of long-term outcomes. Here, we propose a hierarchical Bayesian dynamic (i.e., state-space) model (HBDM) to forecast long-term changes in a motor outcome due to rehabilitation in the chronic phase post-stroke. METHODS: The model incorporates the effects of clinician-supervised training, self-training, and forgetting. In addition, to improve forecasting early in rehabilitation, when data are sparse or unavailable, we use the Bayesian hierarchical modeling technique to incorporate prior information from similar patients. We use HBDM to re-analyze the Motor Activity Log (MAL) data of participants with chronic stroke included in two clinical trials: (1) the DOSE trial, in which participants were assigned to a 0, 15, 30, or 60-h dose condition (data of 40 participants analyzed), and (2) the EXCITE trial, in which participants were assigned a 60-h dose, in either an immediate or a delayed condition (95 participants analyzed). RESULTS: For both datasets, HBDM accounts well for individual dynamics in the MAL during and outside of training: mean RMSE = 0.28 for all 40 DOSE participants (participant-level RMSE 0.26 ± 0.19-95% CI) and mean RMSE = 0.325 for all 95 EXCITE participants (participant-level RMSE 0.32 ± 0.31), which are small compared to the 0-5 range of the MAL. Bayesian leave-one-out cross-validation shows that the model has better predictive accuracy than static regression models and simpler dynamic models that do not account for the effect of supervised training, self-training, or forgetting. We then showcase model's ability to forecast the MAL of "new" participants up to 8 months ahead. The mean RMSE at 6 months post-training was 1.36 using only the baseline MAL and then decreased to 0.91, 0.79, and 0.69 (respectively) with the MAL following the 1st, 2nd, and 3rd bouts of training. In addition, hierarchical modeling improves prediction for a patient early in training. Finally, we verify that this model, despite its simplicity, can reproduce previous findings of the DOSE trial on the efficiency, efficacy, and retention of motor therapy. CONCLUSIONS: In future work, such forecasting models can be used to simulate different stages of recovery, dosages, and training schedules to optimize rehabilitation for each person. Trial registration This study contains a re-analysis of data from the DOSE clinical trial ID NCT01749358 and the EXCITE clinical trial ID NCT00057018.

Understanding stroke survivors' preferences regarding wearable sensor feedback on functional movement: a mixed-methods study.

BACKGROUND: In stroke rehabilitation, wearable technology can be used as an intervention modality by providing timely, meaningful feedback on motor performance. Stroke survivors' preferences may offer a unique perspective on what metrics are intuitive, actionable, and meaningful to change behavior. However, few studies have identified feedback preferences from stroke survivors. This project aims to determine the ease of understanding and movement encouragement of feedback based on wearable sensor data (both arm/hand use and mobility) for stroke survivors and to identify preferences for feedback metrics (mode, content, frequency, and timing). METHODS: A sample of 30 chronic stroke survivors wore a multi-sensor system in the natural environment over a 1-week monitoring period. The sensor system captured time in active movement of each arm, arm use ratio, step counts and stance time symmetry. Using the data from the monitoring period, participants were presented with a movement report with visual displays of feedback about arm/hand use, step counts and gait symmetry. A survey and qualitative interview were used to assess ease of understanding, actionability and components of feedback that users found most meaningful to drive lasting behavior change. RESULTS: Arm/hand use and mobility sensor-derived feedback metrics were easy to understand and actionable. The preferred metric to encourage arm/hand use was the hourly arm use bar plot, and similarly the preferred metric to encourage mobility was the hourly steps bar plot, which were each ranked as top choice by 40% of participants. Participants perceived that quantitative (i.e., step counts) and qualitative (i.e., stance time symmetry) mobility metrics provided complementary information. Three main themes emerged from the qualitative analysis: (1) Motivation for behavior change, (2) Real-time feedback based on individual goals, and (3) Value of experienced clinicians for prescription and accountability. Participants stressed the importance of having feedback tailored to their own personalized goals and receiving guidance from clinicians on strategies to progress and increase functional movement behavior in the unsupervised home and community setting. CONCLUSION: The resulting technology has the potential to integrate engineering and personalized rehabilitation to maximize participation in meaningful life activities outside clinical settings in a less structured environment.

Effort, success, and side of lesion determine arm choice in individuals with chronic stroke.

In neurotypical individuals, arm choice in reaching movements depends on expected biomechanical effort, expected success, and a handedness bias. Following a stroke, does arm choice change to account for the decreased motor performance, or does it follow a preinjury habitual preference pattern? Participants with mild-to-moderate chronic stroke who were right-handed before stroke performed reaching movements in both spontaneous and forced-choice blocks, under no-time, medium-time, and fast-time constraint conditions designed to modulate reaching success. Mixed-effects logistic regression models of arm choice revealed that expected effort predicted choices. However, expected success only strongly predicted choice in left-hemiparetic individuals. In addition, reaction times decreased in left-hemiparetic individuals between the no-time and the fast-time constraint conditions but showed no changes in right-hemiparetic individuals. Finally, arm choice in the no-time constraint condition correlated with a clinical measure of spontaneous arm use for right-, but not for left-hemiparetic individuals. Our results are consistent with the view that right-hemiparetic individuals show a habitual pattern of arm choice for reaching movements relatively independent of failures. In contrast, left-hemiparetic individuals appear to choose their paretic left arm more optimally: that is, if a movement with the paretic arm is predicted to be not successful in the upcoming movement, the nonparetic right arm is chosen instead.NEW & NOTEWORTHY Although we are seldom aware of it, we constantly make decisions to use one arm or the other in daily activities. Here, we studied whether these decisions change following stroke. Our results show that effort, success, and side of lesion determine arm choice in a reaching task: whereas left-paretic individuals modified their arm choice in response to failures in reaching the target, right-paretic individuals showed a pattern of choice independent of failures.

Ipsilesional arm training in severe stroke to improve functional independence (IPSI): phase II protocol.

BACKGROUND: We previously characterized hemisphere-specific motor control deficits in the ipsilesional, less-impaired arm of unilaterally lesioned stroke survivors. Our preliminary data indicate these deficits are substantial and functionally limiting in patients with severe paresis. METHODS: We have designed an intervention ("IPSI") to remediate the hemisphere-specific deficits in the ipsilesional arm, using a virtual-reality platform, followed by manipulation training with a variety of real objects, designed to facilitate generalization and transfer to functional behaviors encountered in the natural environment. This is a 2-site (primary site - Penn State College of Medicine, secondary site - University of Southern California), two-group randomized intervention with an experimental group, which receives unilateral training of the ipsilesional arm throughout 3 one-hour sessions per week for 5 weeks, through our Virtual Reality and Manipulation Training (VRMT) protocol. Our control group receives a conventional intervention on the contralesional arm, 3 one-hour sessions per week for 5 weeks, guided by recently released practice guidelines for upper limb rehabilitation in adult stroke. The study aims to include a total of 120 stroke survivors (60 per group) whose stroke was in the territory of the middle cerebral artery (MCA) resulting in severe upper-extremity motor impairments. Outcome measures (Primary: Jebsen-Taylor Hand Function Test, Fugl-Meyer Assessment, Abilhand, Barthel Index) are assessed at five evaluation points: Baseline 1, Baseline 2, immediate post-intervention (primary endpoint), and 3-weeks (short-term retention) and 6-months post-intervention (long-term retention). We hypothesize that both groups will improve performance of the targeted arm, but that the ipsilesional arm remediation group will show greater improvements in functional independence. DISCUSSION: The results of this study are expected to inform upper limb evaluation and treatment to consider ipsilesional arm function, as part of a comprehensive physical rehabilitation strategy that includes evaluation and remediation of both arms. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov (Registration ID: NCT03634397 ; date of registration: 08/16/2018).

Young adults with recurrent low back pain demonstrate altered trunk coordination during gait independent of pain status and attentional demands.

Pain influences both attention and motor behavior. We used a dual-task interference paradigm to investigate (1) alterations in attentional performance, (2) the ability to switch task prioritization, and (3) the effect of attentional demand on trunk coordination during narrow-based walking in and out of a painful episode in individuals with recurrent low back pain (LBP). We tested twenty young adults with LBP both in and out of a painful episode and compared them to twenty matched back-healthy individuals. Participants simultaneously performed a narrow step width matching task and an arithmetic task, with and without instructions to prioritize either task. A motion capture system was used to record kinematic data, and frontal plane trunk coordination was analyzed using vector coding on the thorax and pelvis angles. Single-task performance, dual-task effect, dual-task performance variability, task prioritization switch, and trunk coordination were analyzed using paired t tests or repeated measures two-way ANOVAs. Results indicated that active pain has a detrimental effect on attentional processes, indicated by poorer single-task performance and increased dual-task performance variability for individuals with recurrent LBP. Individuals with LBP, regardless of pain status, were able to switch task prioritization to a similar degree as their back-healthy counterparts. Compared to the control group, individuals with recurrent LBP exhibited a less in-phase, more pelvis-dominated trunk coordination during narrow-based walking, independent of pain status and regardless of attentional manipulations. Thus, altered trunk coordination in persons with LBP appears to be habitual, automatic, and persists beyond symptom duration.

Corticospinal Tract Microstructure Predicts Distal Arm Motor Improvements in Chronic Stroke.

BACKGROUND AND PURPOSE: The corticospinal tract (CST) is a crucial brain pathway for distal arm and hand motor control. We aimed to determine whether a diffusion tensor imaging (DTI)-derived CST metric predicts distal upper extremity (UE) motor improvements in chronic stroke survivors. METHODS: We analyzed clinical and neuroimaging data from a randomized controlled rehabilitation trial. Participants completed clinical assessments and neuroimaging at baseline and clinical assessments 4 months later, postintervention. Using univariate linear regression analysis, we determined the linear relationship between the DTI-derived CST fractional anisotropy asymmetry (FAasym) and the percentage of baseline change in log-transformed average Wolf Motor Function Test time for distal items (ΔlnWMFT-distal_%). The least absolute shrinkage and selection operator (LASSO) linear regressions with cross-validation and bootstrapping were used to determine the relative weighting of CST FAasym, other brain metrics, clinical outcomes, and demographics on distal motor improvement. Logistic regression analyses were performed to test whether the CST FAasym can predict clinically significant UE motor improvement. RESULTS: lnWMFT-distal significantly improved at the group level. Baseline CST FAasym explained 26% of the variance in ΔlnWMFT-distal_%. A multivariate LASSO model including baseline CST FAasym, age, and UE Fugl-Meyer explained 39% of the variance in ΔlnWMFT-distal_%. Further, CST FAasym explained more variance in ΔlnWMFT-distal_% than the other significant predictors in the LASSO model. DISCUSSION AND CONCLUSIONS: CST microstructure is a significant predictor of improvement in distal UE motor function in the context of an UE rehabilitation trial in chronic stroke survivors with mild-to-moderate motor impairment.Video Abstract available for more insight from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A350).

Inaccurate Use of the Upper Extremity Fugl-Meyer Negatively Affects Upper Extremity Rehabilitation Trial Design: Findings From the ICARE Randomized Controlled Trial.

OBJECTIVE: To determine the extent to which estimates of sample and effect size in stroke rehabilitation trials can be affected by simple summation of ordinal Upper Extremity Fugl-Meyer (UEFM) items compared with a Rasch-rescaled UEFM. DESIGN: Rasch analysis of Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) phase III trial data, comparing 3 upper extremity (UE) motor treatments in stroke survivors enrolled 45.8±22.4 days poststroke. Participants underwent a structured UE motor training known as the Accelerated Skill Acquisition Program, usual and customary care, or dose-equivalent care. UEFM data from baseline, postintervention, and 6 and 12 months later were included for analysis. SETTING: Outpatient stroke rehabilitation. PARTICIPANTS: ICARE participants (N=361). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Item difficulties, person abilities, and sample size. RESULTS: Because of their ordinality, summed raw UEFM scores measured motor impairment inconsistently across different ranges of stroke severity relative to the rescaled UEFM. In the full ICARE sample, raw UEFM understated scores relative to the rescaled UEFM by 7.4 points for the most severely impaired, but overstated scores by up to 8.4 points toward the ceiling. As a result, 50.9% of all UEFM observations showed a residual error greater than 10% of the total UEFM score. Relative to the raw scores, the rescaled UEFM improved the effect size of change in motor impairment between baseline and 1 year (d=0.35). For a hypothetical 3-arm trial resembling ICARE, UEFM rescaling reduced the required sample size by 32% (n=108) compared with raw UEFM (n=159). CONCLUSIONS: In UE rehabilitation trials, a rescaled UEFM potentially decreases sample size by one-third, decreasing costs, duration, and the number of subjects exposed to experimental risks. This benefit is obtained through increased measurement efficiency. Reductions in ceiling effects are also possible. These findings apply to ICARE-like trials. Confirmatory validation in another phase III trial is needed.

Expectancy and affective response to challenging balance practice conditions in individuals with Parkinson's disease.

Psychological states can influence motor performance and learning. In Parkinson's disease (PD), placebo effects or expectancies for pharmacological treatment benefits are not uncommon, but little is known about whether self-efficacy, beliefs about personal performance capabilities, may play a role in this population. To address this question, we investigated whether experimental manipulations designed to enhance self-efficacy would benefit motor performance and learning in PD. A motor learning paradigm was utilized to determine the short-term (i.e., practice) and longer-term (i.e., retention) impact of self-efficacy enhancement when 44 individuals with PD (Hoehn and Yahr stage I-III) acquired a challenging balance skill. Using stratified randomization by Hoehn and Yahr stage, participants were assigned to a control group or one of two investigational groups: (a) an expectancy-relevant statement that encouraged an incremental mindset in which the balance skill, though initially challenging, was acquirable with practice (incremental theory group, IT), and (b) the expectancy-relevant statement in combination with a criterion for successful performance (incremental theory plus success criteria group, IT + SC). All groups improved their balance performance, but contrary to expectations, investigational groups did not outperform the control group at practice or retention. Unexpectedly, the IT + SC group reported greater nervousness than the control and IT groups, suggesting that the employed success criteria may have induced performance-related anxiety. Regression analyses revealed that self-efficacy increase from initial practice predicted performance at the end of practice and at retention. These findings highlight the potential contribution of psychological factors on motor function and rehabilitation in individuals with PD.

Persons in remission from recurrent low back pain alter trunk coupling under dual-task interference during a dynamic balance task.

This study investigated effects of cognitive dual-task interference and task prioritization instructions on task performance and trunk control during a dynamic balance task in persons with and without recurrent low back pain (rLBP). First, we tested the hypothesis that those with rLBP rely more on cognitive resources than back-healthy controls, and therefore trunk kinematics would be altered under dual-task interference conditions. Then, we tested participants' ability to modulate task performance in accord with prioritization instructions. Persons with and without rLBP (n = 19/group) performed the Balance-Dexterity Task, which involved single-limb balance while compressing an unstable spring with the other limb, with and without a cognitive task engaging verbal working memory. Trunk coupling was quantified with the coefficient of determination (R2) of an angle-angle plot of thorax-pelvis frontal plane motion. Task performance was quantified using variability of spring compression force and of cognitive task errors. Trunk coupling in the rLBP group was lower than that of the back-healthy control group in the single-task condition (p = 0.024) and increased in the dual-task condition (p = 0.006), abolishing the difference between groups. Significant main effects of task prioritization instruction on performance were observed with no differences between groups, indicating similar performance modulation. Cognitive task error variability decreased with a switch from a single- to dual-task condition, exposing an unexpected facilitation effect. We interpret these findings in the context of movement-specific reinvestment and action-specific perception theories as they pertain to cognitive contributions to posture and how the dual-task interference paradigm may influence those contributions.

The probability of choosing both hands depends on an interaction between motor capacity and limb-specific control in chronic stroke.

A goal of rehabilitation after stroke is to promote pre-stroke levels of arm use for every day, frequently bimanual, functional activities. We reasoned that, after a stroke, the choice to use one or both hands for bimanual tasks might depend not only on residual motor capacity, but also the specialized demands imposed by the task on the paretic hand. To capture spontaneous, task-specific choices, we covertly observed 50 pre-stroke right-handed chronic stroke survivors (25 each of left, LHD, and right-hemisphere damage, RHD) and 11 age-similar control adults and recorded their hand use strategies for two pairs of bimanual tasks with distinct demands: one with greater precision requirements (photo-album tasks), and another with greater stabilization requirements (letter-envelope tasks). The primary outcome was the choice to use one or both hands. Logistic regression was used to test the two hypotheses that the probability of choosing a bimanual strategy would be greater in those with less severe motor impairment and also in those with LHD. When collapsed across the four tasks, we found support for these hypotheses. Notably, however, the influence of these factors on bimanual choice varied based on task demands. For the photo-album pair, the probability of a bimanual strategy was greater for those with LHD compared to RHD, regardless of the degree of motor impairment. For the letter-envelope pair, we found a significant interaction between impairment and side of lesion in determining the likelihood of choosing both hands. Therefore, the manner in which side of lesion moderates the effect of impairment on hand use depends on the task.

A Reaching Performance Scale for 2 Wolf Motor Function Test Items.

OBJECTIVE: To adapt the Reaching Performance Scale for Stroke (RPSS) for the Wolf Motor Function Test (WMFT) "Lift Can" (Can) and "Hand to Box" (Box) items. DESIGN: Retrospective analysis of video-recorded WMFT assessment performed by 3 raters on 2 occasions. SETTING: Not applicable. PARTICIPANTS: Participants (N=29) with mild to moderate upper extremity impairment less than 3 months after stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Inter- and intra-rater agreement, concurrent validity of WMFT-RPSS. RESULTS: Mean ± SD inter-rater Gwet's agreement coefficient (AC2) was 0.61±0.05 for Can WMFT-RPSS and 0.56 (0.03) for Box. Mean ± SD intra-rater AC2 for Can was 0.63±0.05 and 0.70±0.04 for Box. WMFT-RPSS Can and Box scores correlated with log mean WMFT time (C, -0.73; B, -0.48), Functional Ability Scale (C, 0.87; B, 0.62), Upper Extremity Fugl-Meyer Motor Score (C, 0.69; B, 0.51), and item movement rate (C, 0.74; B, 0.71) (P<.05 for all). Mean ± SD WMFT-RPSS score across the 29 participants was 12.7±3.5 for Can (max score, 19) and 11.4±3.0 for Box (max score, 16). CONCLUSIONS: WMFT-RPSS demonstrated moderate intra-rater and weak-to-moderate inter-rater agreement for individuals with mild-moderate impairment. For construct validity, Can and Box WMFT-RPSS were significantly correlated with 4 standardized measures. Average WMFT-RPSS scores revealed that some participants may have relied on compensatory movements to complete the task, a revelation not discernable from movement rate alone. The WMFT-RPSS is potentially useful as a valid and reliable tool to examine longitudinal changes in movement quality after stroke.

An investigation into the validity and reliability of mHealth devices for counting steps in chronic stroke survivors.

OBJECTIVE: To investigate the validity and test-retest reliability of mHealth devices (Google Fit, Health, STEPZ, Pacer, and Fitbit Ultra) to estimate the number of steps in individuals after chronic stroke and to compare whether the measurement of the number of steps is affected by their location on the body (paretic and non-paretic side). DESIGN: Observational study with repeated measures. SETTING: University laboratory. SUBJECTS: Fifty-five community-dwelling individuals with chronic stroke. INTERVENTION: Not applicable. MAIN MEASURES: The number of steps was measured using mHealth devices (Google Fit, Health, STEPZ, Pacer, and Fitbit Ultra), and compared against criterion-standard measure during the Two-Minute Walk Test using habitual speed. RESULTS: Our sample was 54.5% men, mean age of 62.5 years (SD 14.9) with a chronicity after stroke of 66.8 months (SD 55.9). There was a statistically significant association between the actual number of steps and those estimated by the Google Fit, STEPZ Iphone and Android applications, Pacer iphone and Android, and Fitbit Ultra (0.30 ⩽ r ⩾ 0.80). The Pacer iphone application demonstrated the highest reliability coefficient (ICC(2,1) = 0.80; P < 0.001). There were no statistically significant differences in device measurements that depended on body location. CONCLUSIONS: mHealth devices (Pacer-iphone, Fitbit Ultra, Google Fit, and Pacer-Android) are valid and reliable for step counting in chronic stroke survivors. Body location (paretic or non-paretic side) does not affect validity or reliability of the step count metric.

Dosage Matters.

Background and Purpose- For stroke rehabilitation, task-specific training in animal models and human rehabilitation trials is considered important to modulate neuroplasticity, promote motor learning, and functional recovery. Little is known about what constitutes an effective dosage of therapy. Methods- This is a parallel group, 4 arms, single-blind, phase IIb, randomized controlled trial of 4 dosages of arm therapy delivered in an outpatient setting chronically after stroke. Participants were randomized into groups that varied in duration of scheduled therapy (ie, 0, 15, 30, or 60 hours). Forty-one participants completed the study. Planned primary analyses used linear mixed effects regression to model changes from baseline to postintervention in the Motor Activity Log-Quality of Movement rating and the Wolf Motor Function Test time score over 3 weeks of training as a function of therapy dosage. Results- We observed a dose response for the Motor Activity Log-Quality of Movement: the model that included dose and dose by week interaction significantly better fit the data than the model that included week only (log-likelihood test, P=0.0026). In addition, the greater the dosage of training, the greater the change in Motor Activity Log-Quality of Movement, with the dose by week interaction parameter equal to 0.0045 ( P=0.0016; 95% CI, 0.0018-0.0071). Over the 3 weeks of therapy, there was a gain of 0.92 in Motor Activity Log-Quality of Movement for the 60-hour group compared to the 0-hour group. There was no dose response for the Wolf Motor Function Test. Conclusions- For mild-to-moderately impaired stroke survivors, the dosage of patient-centered, task-specific practice systematically influences the gain in quality of arm use but not functional capacity. We caution that we may have been underpowered for the functional capacity outcome. These findings highlight the importance of recovery outcomes that capture arm use in the natural environment. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01749358.

Development of a training paradigm for voluntary control of the peri-auricular muscles: a feasibility study.

BACKGROUND: Spinal cord injury (SCI) can lead to severe and permanent functional deficits. In humans, peri-auricular muscles (PAMs) do not serve any physiological function, though their innervation is preserved in even high level SCI. Auricular control systems provide a good example of leveraging contemporary technologies (e.g., sEMG controlled computer games) to enable those with disabilities. Our primary objective is to develop and test the effectiveness of an auricular muscle training protocol to facilitate isolated and coordinated, bilateral voluntary control that could be used in individuals without volitional control of the vestigial PAMs. METHODS: Seventeen non-disabled persons were screened; 13 were eligible and 10 completed the entire protocol. The facilitation phase, included one session of sub-motor threshold, sensory electrical stimulation followed by neuromuscular electrical stimulation paired with ear movement feedback for up to 8 additional sessions. Participants progressed to the skill acquisition phase where they dawned an auricular control device that used sEMG signals to control movements of a cursor through three levels of computer games, each requiring increasingly more complex PAM coordination. RESULTS: The 10 who completed the protocol, finished the facilitation phase in 3 to 9 sessions and achieved some level of voluntary auricle movement that ranged between 1 and 5 mm. Qualitative analysis of longitudinal post-session auricular movement, revealed two subgroups of learners. Six successfully completed all 3 games-the "Learners". Two were partially successful in game completion and two were unable to complete a single game--"Poor/Non-Learners". Quantitative analysis revealed a significant group difference in auricular amplitude for both facilitation and skill phases (p < .05), and a significant relationship between performance in the two phases (R2 = 0.84, p = 0.004). CONCLUSION: Sixty percent of those who completed the facilitation phase were able to learn and demonstrate functional voluntary control of the vestigial PAMs. Those who progressed the fastest through facilitation were also those who were most proficient in skill acquisition with the device. There was considerable variability in progression through the two-phase protocol, with 20% deemed Poor/Non-Learners and unable to complete even the most basic game following training. There were no serious adverse events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02358915 , first posted February 9, 2015.

Medical Rehabilitation: Guidelines to Advance the Field With High-Impact Clinical Trials.

The purpose of this Special Communication is to summarize guidelines and recommendations stemming from an expert panel convened by the National Institutes of Health, National Center for Medical Rehabilitation Research (NCMRR) for a workshop entitled The Future of Medical Rehabilitation Clinical Trials, held September 29-30, 2016, at the NCMRR offices in Bethesda, Maryland. The ultimate goal of both the workshop and this summary is to offer guidance on clinical trials design and operations to the medical rehabilitation research community, with the intent of maximizing the effect of future trials.

Laterality of Poststroke Cortical Motor Activity during Action Observation Is Related to Hemispheric Dominance.

Background: Increased activity in the lesioned hemisphere has been related to improved poststroke motor recovery. However, the role of the dominant hemisphere-and its relationship to activity in the lesioned hemisphere-has not been widely explored. Objective: Here, we examined whether the dominant hemisphere drives the lateralization of brain activity after stroke and whether this changes based on if the lesioned hemisphere is the dominant hemisphere or not. Methods: We used fMRI to compare cortical motor activity in the action observation network (AON), motor-related regions that are active both during the observation and execution of an action, in 36 left hemisphere dominant individuals. Twelve individuals had nondominant, right hemisphere stroke, twelve had dominant, left-hemisphere stroke, and twelve were healthy age-matched controls. We previously found that individuals with left dominant stroke show greater ipsilesional activity during action observation. Here, we examined if individuals with nondominant, right hemisphere stroke also showed greater lateralized activity in the ipsilesional, right hemisphere or in the dominant, left hemisphere and compared these results with those of individuals with dominant, left hemisphere stroke. Results: We found that individuals with right hemisphere stroke showed greater activity in the dominant, left hemisphere, rather than the ipsilesional, right hemisphere. This left-lateralized pattern matched that of individuals with left, dominant hemisphere stroke, and both stroke groups differed from the age-matched control group. Conclusions: These findings suggest that action observation is lateralized to the dominant, rather than ipsilesional, hemisphere, which may reflect an interaction between the lesioned hemisphere and the dominant hemisphere in driving lateralization of brain activity after stroke. Hemispheric dominance and laterality should be carefully considered when characterizing poststroke neural activity.