Improvement after constraint-induced movement therapy: recovery of normal motor control or task-specific compensation?

Motion Analysis of the Mug Transportation Task Through Upper Limb Kinematics

The task of transporting objects is a fundamental part of daily living activities. Previous kinematic studies focusing on tasks such as pointing, reach-to-grasp, and drinking have not fully captured the motor behaviors involved in object transportation, including placing a cup on a table or storing items in specific places. Hence, this study aimed to analyze the motor behavior associated with transporting a mug using upper limb kinematic variables. Fifteen healthy adults were instructed to transport an open-handle mug across a table. The kinematic metrics evaluated included object end-error for accuracy, frontal and lateral end-range for precision, movement time, peak velocity, time to peak velocity for control strategy, object path ratio for efficiency, and interjoint coordination. The stability of motor behavior was assessed through a test-retest analysis. The mug transporting task achieved accuracy with a radius <10 mm around the target, a peak velocity of ∼0.4 m/s, a control strategy where acceleration time constituted about 30% of the movement time, and a slightly curved trajectory. The test-retest analysis confirmed stable motor behavior across all kinematic metrics (ICCs > 0.75). Thus, the mug transporting task exhibited unique and stable kinematic characteristics, distinguishing it from non-transport activities and effectively mirroring transporting activities of daily living.

Transforming modeling in neurorehabilitation: clinical insights for personalized rehabilitation

Practicing clinicians in neurorehabilitation continue to lack a systematic evidence base to personalize rehabilitation therapies to individual patients and thereby maximize outcomes. Computational modeling- collecting, analyzing, and modeling neurorehabilitation data- holds great promise. A key question is how can computational modeling contribute to the evidence base for personalized rehabilitation? As representatives of the clinicians and clinician-scientists who attended the 2023 NSF DARE conference at USC, here we offer our perspectives and discussion on this topic. Our overarching thesis is that clinical insight should inform all steps of modeling, from construction to output, in neurorehabilitation and that this process requires close collaboration between researchers and the clinical community. We start with two clinical case examples focused on motor rehabilitation after stroke which provide context to the heterogeneity of neurologic injury, the complexity of post-acute neurologic care, the neuroscience of recovery, and the current state of outcome assessment in rehabilitation clinical care. Do we provide different therapies to these two different patients to maximize outcomes? Asking this question leads to a corollary: how do we build the evidence base to support the use of different therapies for individual patients? We discuss seven points critical to clinical translation of computational modeling research in neurorehabilitation- (i) clinical endpoints, (ii) hypothesis- versus data-driven models, (iii) biological processes, (iv) contextualizing outcome measures, (v) clinical collaboration for device translation, (vi) modeling in the real world and (vii) clinical touchpoints across all stages of research. We conclude with our views on key avenues for future investment (clinical-research collaboration, new educational pathways, interdisciplinary engagement) to enable maximal translational value of computational modeling research in neurorehabilitation.

Direction-dependent differences in the quality and quantity of horizontal reaching in people after stroke

Arm reaching is often impaired in individuals with stroke. Nonetheless, how aiming directions influence reaching performance and how such differences change with motor recovery over time remain unclear. Here, we elucidated kinematic parameters of reaching toward various directions in people with poststroke hemiparesis in the subacute phase. A total of 13 and 15 participants with mild and moderate-to-severe hemiparesis, respectively, performed horizontal reaching in eight directions with their more-affected and less-affected sides using an exoskeleton robotic device at the time of admission to and discharge from the rehabilitation ward of the hospital. The movement time, path length, and number of velocity peaks were computed for the mild group (participants able to reach toward all eight directions). In addition, the total amount of displacement (i.e., movement quantity) toward two simplified directions (mediolateral or anteroposterior) was evaluated for the moderate-to-severe group (participants who showed difficulty in completing the reaching task). Motor recovery was evaluated using the Fugl-Meyer assessment. The mild group showed worse values of movement parameters during reaching in the anteroposterior direction, irrespective of the side of the arm or motor recovery achieved. The moderate-to-severe group exhibited less movement toward the anteroposterior direction than toward the mediolateral direction at admission; however, this direction-dependent bias in movement quantity decreased, with the movement expanding toward the anteroposterior direction with motor recovery at discharge. These results suggest that direction-dependent differences in the quality and quantity of reaching performance exist in people after stroke, regardless of the presence or severity of hemiparesis. This highlights the need to consider the task work area when designing rehabilitative training.NEW & NOTEWORTHY Arm reaching, a fundamental function required for the upper extremities, is often impaired after stroke due to muscle weakness and abnormal synergies. Nonetheless, how aiming directions influence performance remains unclear. Here, we report that direction-dependent differences in the quality and quantity of reaching performance exist, surprisingly regardless of the presence or severity of hemiparesis. This result highlights the need to consider the task work area when designing rehabilitative training.

Improvement of speed-accuracy tradeoff during practice of a point-to-point task in children with acquired dystonia

The tradeoff between speed and accuracy is a well-known constraint for human movement, but previous work has shown that this tradeoff can be modified by practice, and the quantitative relationship between speed and accuracy may be an indicator of skill in some tasks. We have previously shown that children with dystonia are able to adapt their movement strategy in a ballistic throwing game to compensate for increased variability of movement. Here, we test whether children with dystonia can adapt and improve skills learned on a trajectory task. We use a novel task in which children move a spoon with a marble between two targets. Difficulty is modified by changing the depth of the spoon. Our results show that both healthy children and children with acquired dystonia move more slowly with the more difficult spoons, and both groups improve the relationship between speed and spoon difficulty following 1 wk of practice. By tracking the marble position in the spoon, we show that children with dystonia use a larger fraction of the available variability, whereas healthy children adopt a much safer strategy and remain farther from the margins, as well as learning to adapt and have more control over the marble's utilized area by practice. Together, our results show that both healthy children and children with dystonia choose trajectories that compensate for risk and inherent variability, and that the increased variability in dystonia can be modified with continued practice.NEW & NOTEWORTHY This study provides insights into the adaptability of children with dystonia in learning a point-to-point task. We show that these children adjust their strategies to account for increased difficulty in the task. Our findings underscore the potential of task-specific practice in improving motor skills and show higher level of signal-dependent noise can be controlled through repetition and learned strategies, which provides an avenue for the quantitative evaluation of rehabilitation strategies in this challenging group.

Measuring Arm and Hand Joint Kinematics to Estimate Impairment During a Functional Reach and Grasp Task after Stroke

BACKGROUND

Current approaches to characterizing deficits in upper limb movements after stroke typically focus either on changes in a functional measure, for example, how well a patient can complete a task, or changes in impairment, for example, isolated measurements of joint range of motion. However, there can be notable dissociations between static measures of impairment versus those of function.

OBJECTIVE

We develop a method to measure upper limb joint angles during performance of a functional task and use measurements to characterize joint impairment in the context of a functional task.

METHODS

We developed a sensorized glove that can precisely measure select finger, hand, and arm joints while participants complete a functional reach-to-grasp task involving manipulation of a sensorized object.

RESULTS

We first characterized the accuracy and precision of the glove's joint angle measurements. We then measured joint angles in neurologically intact participants (n = 4 participants, 8 limbs) to define the expected distribution of joint angle variation during task execution. These distributions were used to normalize finger, hand, and arm joint angles in stroke participants (n = 6) as they performed the task. We present a participant-specific visualization of functional joint angle variance which illustrated that stroke participants with nearly identical clinical scores exhibited unique patterns of joint angle variation.

CONCLUSIONS

Overall, measuring individual joint angles in the context of a functional task may inform whether changes in functional scores over recovery or rehabilitation are driven by changes in impairment or the development of compensatory strategies, and provide a quantified path toward personalized rehabilitative therapy.

Quantifying intra- and interlimb use during unimanual and bimanual tasks in persons with hemiparesis post-stroke

Background

Individuals with hemiparesis post-stroke often have difficulty with tasks requiring upper extremity (UE) intra- and interlimb use, yet methods to quantify both are limited.

Objective

To develop a quantitative yet sensitive method to identify distinct features of UE intra- and interlimb use during task performance.

Methods

Twenty adults post-stroke and 20 controls wore five inertial sensors (wrists, upper arms, sternum) during 12 seated UE tasks. Three sensor modalities (acceleration, angular rate of change, orientation) were examined for three metrics (peak to peak amplitude, time, and frequency). To allow for comparison between sensor data, the resultant values were combined into one motion parameter, per sensor pair, using a novel algorithm. This motion parameter was compared in a group-by-task analysis of variance as a similarity score (0–1) between key sensor pairs: sternum to wrist, wrist to wrist, and wrist to upper arm. A use ratio (paretic/non-paretic arm) was calculated in persons post-stroke from wrist sensor data for each modality and compared to scores from the Adult Assisting Hand Assessment (Ad-AHA Stroke) and UE Fugl-Meyer (UEFM).

Results

A significant group × task interaction in the similarity score was found for all key sensor pairs. Post-hoc tests between task type revealed significant differences in similarity for sensor pairs in 8/9 comparisons for controls and 3/9 comparisons for persons post stroke. The use ratio was significantly predictive of the Ad-AHA Stroke and UEFM scores for each modality.

Conclusions

Our algorithm and sensor data analyses distinguished task type within and between groups and were predictive of clinical scores. Future work will assess reliability and validity of this novel metric to allow development of an easy-to-use app for clinicians.

Reward and plasticity: Implications for neurorehabilitation

Neuroplasticity follows nervous system injury in the presence or absence of rehabilitative treatments. Rehabilitative interventions can be used to modulate adaptive neuroplasticity, reducing motor impairment and improving activities of daily living in patients with brain lesions. Learning principles guide some rehabilitative interventions. While basic science research has shown that reward combined with training enhances learning, this principle has been only recently explored in the context of neurorehabilitation. Commonly used reinforcers may be more or less rewarding depending on the individual or the context in which the task is performed. Studies in healthy humans showed that both reward and punishment can enhance within-session motor performance; but reward, and not punishment, improves consolidation and retention of motor skills. On the other hand, neurorehabilitative training after brain lesions involves complex tasks (e.g., walking and activities of daily living). The contribution of reward to neurorehabilitation is incompletely understood. Here, we discuss recent research on the role of reward in neurorehabilitation and the needed directions of future research.

Improving upper-limb and trunk kinematics by interactive gaming in individuals with chronic stroke: a single-blinded RCT

BACKGROUND

. Commercial gaming systems are increasingly being used for stroke rehabilitation; however, their effect on upper-limb recovery versus compensation is unknown.

OBJECTIVES

. We aimed to compare the effect of upper-limb rehabilitation using interactive gaming (Nintendo Wii) with dose-matched conventional therapy on elbow extension (recovery) and forward trunk motion (compensation) in individuals with chronic stroke. Secondary aims were to compare the effect on 1) clinical tests of impairment and activity, pain and effort, and 2) trajectory kinematics. We also explored arm and trunk motion (acceleration) during Wii sessions to understand how participants performed movements during Wii gaming.

METHODS

. This single-centre, randomized controlled trial compared 12 hourly sessions over 4 weeks of upper-limb Wii therapy to conventional therapy. Outcomes were evaluated at baseline and 4 weeks. The change in elbow extension and trunk motion during a reaching task was evaluated by electromagnetic sensors. Secondary outcomes were change in Fugl-Meyer assessment, Box and Block test, Action Research Arm Test, Motor Activity Log, and Stroke Impact Scale scores. Arm and trunk acceleration during Wii therapy was evaluated by using inertial sensors. A healthy control group was included for reference data.

RESULTS

. Nineteen participants completed Wii therapy and 21 conventional therapy (mean [SD] time post-stroke 66.4 [57.2] months). The intervention and control groups did not differ in mean change in elbow extension angle (Wii: +4.5°, 95% confidence interval [CI] 0.1; 9.1; conventional therapy: +6.4°, 95%CI 0.6; 12.2) and forward trunk position (Wii: -3.3 cm, 95%CI -6.2;-0.4]; conventional therapy: -4.1 cm, 95%CI -6.6; -1.6) (effect size: elbow, d=0.16, p=0.61; trunk, d=0.13, p=0.65). Clinical scores improved similarly but to a small extent in both groups. The amount of arm but not trunk acceleration produced during Wii sessions increased with training.

CONCLUSIONS

. Supervised upper-limb gaming therapy induced similar recovery of elbow extension as conventional therapy and did not enhance the development of compensatory forward trunk movement in individuals with chronic stroke. More sessions may be necessary to induce greater improvements.

Wearable myoelectric interface enables high-dose, home-based training in severely impaired chronic stroke survivors

Background

High‐intensity occupational therapy can improve arm function after stroke, but many people lack access to such therapy. Home‐based therapies could address this need, but they don’t typically address abnormal muscle co‐activation, an important aspect of arm impairment. An earlier study using lab‐based, myoelectric computer interface game training enabled chronic stroke survivors to reduce abnormal co‐activation and improve arm function. Here, we assess feasibility of doing this training at home using a novel, wearable, myoelectric interface for neurorehabilitation training (MINT) paradigm.

Objective

Assess tolerability and feasibility of home‐based, high‐dose MINT therapy in severely impaired chronic stroke survivors.

Methods

Twenty‐three participants were instructed to train with the MINT and game for 90 min/day, 36 days over 6 weeks. We assessed feasibility using amount of time trained and game performance. We assessed tolerability (enjoyment and effort) using a customized version of the Intrinsic Motivation Inventory at the conclusion of training.

Results

Participants displayed high adherence to near‐daily therapy at home (mean of 82 min/day of training; 96% trained at least 60 min/day) and enjoyed the therapy. Training performance improved and co‐activation decreased with training. Although a substantial number of participants stopped training, most dropouts were due to reasons unrelated to the training paradigm itself.

Interpretation

Home‐based therapy with MINT is feasible and tolerable in severely impaired stroke survivors. This affordable, enjoyable, and mobile health paradigm has potential to improve recovery from stroke in a variety of settings.

Clinicaltrials.gov: NCT03401762.

Stroke survivors' perceptions of participating in a high repetition arm training trial early after stroke

PURPOSE

The study explored the acceptability of high repetition arm training as part of a randomised controlled trial, early after stroke, when fatigue levels and emotional strain are often high.

MATERIALS AND METHODS

36 sub-acute stroke survivors (61 years+/-15) attended for assessment sessions at 3, 6, and 12 weeks after stroke. Individuals were randomised to receive 6 high repetition arm training sessions between 3 and 6 weeks (intervention) or the control group. Semi-structured interviews were conducted at trial completion. Interview transcripts were analysed through framework analysis conducted independently by 2 researchers.

RESULTS

Stroke survivors participated despite high levels of fatigue because they hoped for personal benefit or to potentially benefit future patients. Benefits reported from participation included physical improvements, psychological benefit, improved understanding of their condition as well as a feeling of hope and distraction. The arm training at three weeks after stroke, aiming for 420 movement repetitions was not considered to be too intensive or too early, and most individuals felt lucky to have been, or would have preferred to be in the early training group.

CONCLUSION

High repetition arm training early after stroke was acceptable to participants. Study participation was generally viewed as a positive experience, suggesting that early intervention may not only be physically beneficial but also psychologically.Implications for rehabilitationStroke survivors report that high repetition arm training early after stroke is acceptable.Participation in rehabilitation research early after stroke provides stroke survivors with hope and meaning despite the high prevalence of fatigue.Complex information needs to be repeated and provided in a number of formats early after stroke.

Impairment and Compensation in Dexterous Upper-Limb Function After Stroke. From the Direct Consequences of Pyramidal Tract Lesions to Behavioral Involvement of Both Upper-Limbs in Daily Activities

Impairments in dexterous upper limb function are a significant cause of disability following stroke. While the physiological basis of movement deficits consequent to a lesion in the pyramidal tract is well demonstrated, specific mechanisms contributing to optimal recovery are less apparent. Various upper limb interventions (motor learning methods, neurostimulation techniques, robotics, virtual reality, and serious games) are associated with improvements in motor performance, but many patients continue to experience significant limitations with object handling in everyday activities. Exactly how we go about consolidating adaptive motor behaviors through the rehabilitation process thus remains a considerable challenge. An important part of this problem is the ability to successfully distinguish the extent to which a given gesture is determined by the neuromotor impairment and that which is determined by a compensatory mechanism. This question is particularly complicated in tasks involving manual dexterity where prehensile movements are contingent upon the task (individual digit movement, grasping, and manipulation…) and its objective (placing, two step actions…), as well as personal factors (motivation, acquired skills, and life habits…) and contextual cues related to the environment (presence of tools or assistive devices…). Presently, there remains a lack of integrative studies which differentiate processes related to structural changes associated with the neurological lesion and those related to behavioral change in response to situational constraints. In this text, we shall question the link between impairments, motor strategies and individual performance in object handling tasks. This scoping review will be based on clinical studies, and discussed in relation to more general findings about hand and upper limb function (manipulation of objects, tool use in daily life activity). We shall discuss how further quantitative studies on human manipulation in ecological contexts may provide greater insight into compensatory motor behavior in patients with a neurological impairment of dexterous upper-limb function.

How many trials are needed in kinematic analysis of reach-to-grasp?-A study of the drinking task in persons with stroke and non-disabled controls

Background

Kinematic analysis of the 3D reach-to-grasp drinking task is recommended in stroke rehabilitation research. The number of trials required to reach performance stability, as an important aspect of reliability, has not been investigated for this task. Thus, the aims of this study were to determine the number of trials needed for the drinking task to reach within-session performance stability and to investigate trends in performance over a set of trials in non-disabled people and in a sample of individuals with chronic stroke. In addition, the between-sessions test–retest reliability in persons with stroke was established.

Methods

The drinking task was performed at least 10 times, following a standardized protocol, in 44 non-disabled and 8 post-stroke individuals. A marker-based motion capture system registered arm and trunk movements during 5 pre-defined phases of the drinking task. Intra class correlation statistics were used to determine the number of trials needed to reach performance stability as well as to establish test–retest reliability. Systematic within-session trends over multiple trials were analyzed with a paired t-test.

Results

For most of the kinematic variables 2 to 3 trials were needed to reach good performance stability in both investigated groups. More trials were needed for movement times in reaching and returning phase, movement smoothness, time to peak velocity and inter-joint-coordination. A small but significant trend of improvement in movement time over multiple trials was demonstrated in the non-disabled group, but not in the stroke group. A mean of 3 trials was sufficient to reach good to excellent test–retest reliability for most of the kinematic variables in the stroke sample.

Conclusions

This is the first study that determines the number of trials needed for good performance stability (non-disabled and stroke) and test–retest reliability (stroke) for temporal, endpoint and angular metrics of the drinking task. For most kinematic variables, 3–5 trials are sufficient to reach good reliability. This knowledge can be used to guide future kinematic studies.

Dissociating Sensorimotor Recovery and Compensation During Exoskeleton Training Following Stroke

The quality of arm movements typically improves in the sub-acute phase of stroke affecting the upper extremity. Here, we used whole arm kinematic analysis during reaching movements to distinguish whether these improvements are due to true recovery or to compensation. Fifty-three participants with post-acute stroke performed ∼80 reaching movement tests during 4 weeks of training with the ArmeoSpring exoskeleton. All participants showed improvements in end-effector performance, as measured by movement smoothness. Four ArmeoSpring angles, shoulder horizontal (SH) rotation, shoulder elevation (SE), elbow rotation, and forearm rotation, were recorded and analyzed. We first characterized healthy joint coordination patterns by performing a sparse principal component analysis on these four joint velocities recorded during reaching tests performed by young control participants. We found that two dominant joint correlations [SH with elbow rotation and SE with forearm rotation] explained over 95% of variance of joint velocity data. We identified two clusters of stroke participants by comparing the evolution of these two correlations in all tests. In the "Recoverer" cluster (N = 19), both joint correlations converged toward the respective correlations for control participants. Thus, Recoverers relearned how to generate smooth end-effector movements while developing joint movement patterns similar to those of control participants. In the "Compensator" cluster (N = 34), at least one of the two joint correlations diverged from the corresponding correlation of control participants. Compensators relearned how to generate smooth end-effector movements by discovering various new compensatory movement patterns dissimilar to those of control participants. New compensatory patterns included atypical decoupling of the SE and forearm joints, and atypical coupling of the SH rotation and elbow joints. There was no difference in clinical impairment level between the two groups either at the onset or at the end of training as assessed with the Upper Extremity Fugl-Meyer scale. However, at the start of training, the Recoverers showed significantly faster improvements in end-effector movement smoothness than the Compensators. Our analysis can be used to inform neurorehabilitation clinicians on how to provide movement feedback during practice and suggest avenues for refining exoskeleton robot therapy to reduce compensatory patterns.

Shoulder function after constraint-induced movement therapy assessed with 3D kinematics and clinical and patient reported outcomes: A prospective cohort study

INTRODUCTION

We hypothesised that reduced shoulder function post stroke improves during constraint-induced movement therapy and that improvement in scapula upward rotation measured with three-dimensional kinematics is associated with improvements in clinical and patient reported outcomes.

METHODS

Thirty-seven patients were tested pre and post constraint-induced movement therapy and again at three-month follow-up. Kinematic outcome measures - with scapula upward rotation as the primary outcome - during tasks 5 (ReachLow) and 6 (ReachHigh) from the Wolf Motor Function Test were included together with clinical and patient reported outcomes. Changes in outcome measures were analysed with linear mixed models and logistic regression analysis.

FINDINGS

Scapula upward rotation was reduced from 16.2° pre intervention through 15.9° post intervention to 15.6° at three-month follow-up during ReachHigh. Statistically significant reductions of <2° were also found for shoulder flexion during ReachLow and trunk lateral flexion during ReachHigh. The clinical and patient reported outcomes showed improvements post constraint-induced movement therapy, and at follow-up, the outcomes resembled post values.

INTERPRETATION

The minimal improvements in selected 3D kinematic measures of upper extremity movements did not reflect any clinically meaningful changes. Therefore, the clinical and patient reported improvements could not be related to restitution of shoulder function.

Longitudinal analysis of the recovery of trunk control and upper extremity following stroke: An individual growth curve approach

Background and Purpose: Trunk control is thought to contribute to upper extremity function. It is unclear whether recovery of trunk control has an impact on the recovery of the upper extremity in people with stroke. This longitudinal study monitored the recovery of trunk control and upper extremity in the first 6 months following stroke.Methods: Forty-five participants with stroke were assessed monthly for 6 months following stroke. Trunk control was assessed using the Trunk Impairment Scale (TIS); upper extremity impairment and function were assessed with the Fugl-Meyer (FMA) and Streamlined Wolf Motor Function Test (SWMFT) respectively. The SWMFT included the performance time (SWMFT-Time) and functional ability scale (SWMFT-FAS). The individual growth curve modeling was used to analyze the longitudinal data.Results: The recovery curve of TIS, FMA, SWMFT-Time and SWMFT-FAS followed a quadratic trend, with the rate of recovery decreasing from the first to sixth month. As TIS score improved over time, FMA, SWMFT-Time and SWMFT-FAS improved in parallel with the TIS score. TIS at each time point was found to be a significant predictor of FMA, SWMFT-Time and SWMFT-FAS at 6 months post stroke.Conclusion: Our work has provided, for the first time, substantial evidence that the pattern of recovery of trunk control is similar to that of the recovery of upper extremity following stroke. In addition, this study provides evidence on which to design a prospective study to evaluate whether improvement in trunk control early post-stroke results in better long-term upper extremity function.

Five Features to Look for in Early-Phase Clinical Intervention Studies

Neurorehabilitation relies on core principles of neuroplasticity to activate and engage latent neural connections, promote detour circuits, and reverse impairments. Clinical interventions incorporating these principles have been shown to promote recovery and demote compensation. However, many clinicians struggle to find interventions centered on these principles in our nascent, rapidly growing body of literature. Not to mention the immense pressure from regulatory bodies and organizational balance sheets that further discourage time-intensive recovery-promoting interventions, incentivizing clinicians to prioritize practical constraints over sound clinical decision making. Modern neurorehabilitation practices that result from these pressures favor strategies that encourage compensation over those that promote recovery. To narrow the gap between the busy clinician and the cutting-edge motor recovery literature, we distilled 5 features found in early-phase clinical intervention studies-ones that value the more enduring biological recovery processes over the more immediate compensatory remedies. Filtering emerging literature through this lens and routinely integrating promising research into daily practice can break down practical barriers for effective clinical translation and ultimately promote durable long-term outcomes. This perspective is meant to serve a new generation of mechanistically minded and caring clinicians, students, activists, and research trainees, who are poised to not only advance rehabilitation science, but also erect evidence-based policy changes to accelerate recovery-based stroke care.

Effect of Task-Specific Training on Trunk Control and Balance in Patients with Subacute Stroke

Objectives

Impairment of static and dynamic posture control is common after stroke. It is found to be a predictor and an essential component for balance, walking ability, and activities of daily living (ADL) outcomes. Studies investigating effect of physical therapy techniques with an aim to improve trunk function after stroke are limited. This study aimed at studying the effect of task-specific training on trunk control and balance in patients with subacute stroke.

Methods

In this randomized controlled trail, thirty-four patients were alienated into two equal groups. The study group (n = 17) received task-specific training, and the control group (n = 17) received conventional physical therapy based on the neurodevelopmental technique. Task-specific training was applied through two phases with criteria of progression based on Chedoke-McMaster Stroke Assessment postural control stages. The interventions were applied in a dosage of 60 min per session, three times a week for ten weeks. Static and dynamic balance were measured by the trunk impairment scale (TIS), postural assessment scale (PAS), and functional reach test (FRT). Laser-guided digital goniometer was used to measure the trunk ranges of motions (ROM) as a secondary outcome.

Results

Significant differences between the baseline and the follow-up measures including TIS, PAS, FRT, and trunk (ROM) were found in both groups (P ≤ 0.05). In-between group comparison also showed significant differences between the results of both groups indicating more improvements among patients representing the study group.

Conclusion

Task-specific training may be effective in improving the static and dynamic postural control and trunk ranges of motion among subacute stroke patients.

Gains Across WHO Dimensions of Function After Robot-Based Therapy in Stroke Subjects

BACKGROUND

Studies examining the effects of therapeutic interventions after stroke often focus on changes in loss of body function/structure (impairment). However, improvements in activities limitations and participation restriction are often higher patient priorities, and the relationship that these measures have with loss of body function/structure is unclear.

OBJECTIVE

This study measured gains across WHO International Classification of Function (ICF) dimensions and examined their interrelationships.

METHODS

Subjects were recruited 11 to 26 weeks after hemiparetic stroke. Over a 3-week period, subjects received 12 sessions of intensive robot-based therapy targeting the distal arm. Each subject was assessed at baseline and at 1 month after end of therapy.

RESULTS

At baseline, subjects (n = 40) were 134.7 ± 32.4 (mean ± SD) days poststroke and had moderate-severe arm motor deficits (arm motor Fugl-Meyer score of 35.6 ± 14.4) that were stable. Subjects averaged 2579 thumb movements and 1298 wrist movements per treatment session. After robot therapy, there was significant improvement in measures of body function/structure (Fugl-Meyer score) and activity limitations (Action Research Arm Test, Barthel Index, and Stroke Impact Scale-Hand), but not participation restriction (Stroke Specific Quality of Life Scale). Furthermore, while the degree of improvement in loss of body function/structure was correlated with improvement in activity limitations, neither improvement in loss of body function/structure nor improvement in activity limitations was correlated with change in participation restriction.

CONCLUSIONS

After a 3-week course of robotic therapy, there was improvement in body function/structure and activity limitations but no reduction in participation restriction.

A body-weight-supported visual feedback system for gait recovering in stroke patients: A randomized controlled study

OBJECTIVE

The aim of this study was to determine the effectiveness of a novel body-weight-supported (BWS) gait training system with visual feedback, called Copernicus® (Rehalife, Italy). This computerized device provides comfortable, regular and repeatable locomotion in hemiplegic patients. Through visual real-time monitoring of gait parameters, patients are trained to transfer weight loading alternately on both feet.

DESIGN

A single-blind, randomized controlled study. A single center used a computer-generated randomization code to allocate treatments.

SETTING

Intensive rehabilitation unit (IRU) at the Institute S. Anna (Italy).

PARTICIPANTS

63 first-ever stroke patients (39 men, age: 66.1 ± 9.6 years; 61.6 % with left-sided lesion) randomly distributed into three demographically/clinically matched groups.

TREATMENTS

All groups were treated five times a week for 2 -h sessions for six consecutive weeks. The first group ("control") underwent a conventional physical therapy; the second group performed advanced BWS gait training sessions without visual feedback (Experimental VF- group); whereas the third group used BWS with visual feedback stimulation (Experimental VF+ group).

MAIN OUTCOME MEASURES

Absolute changes were recorded using conventional clinical scales and kinematic measurement of static gait balance from baseline to follow-up.

RESULTS

Significant interaction Group*Time effects scales (F_2,126 = 5.1, p-level = 0.005, η²_p = 0.25; F_2,126 = 4.7, p-level = 0.007, η²_p = 0.19; respectively) were detected in the Functional Independence Measure and Tinetti-Balance scales. Post hoc analysis demonstrated that the recovery of motor functioning was greater for the VF + group with respect to other groups (all p's ≤ 0.001). A similar pattern of findings was also obtained with a stabilometric analysis, demonstrating a better clinical improvement in static balance after VF + treatment.

CONCLUSION

The proposed advanced rehabilitation system with visual feedback was more effective in improving gait recovery with respect to conventional and high-tech therapies without a sensor feedback.

Machine Learning for 3D Kinematic Analysis of Movements in Neurorehabilitation

PURPOSE OF REVIEW

Recent advances in the machine learning field, especially in deep learning, provide the opportunity for automated, detailed, and unbiased analysis of motor behavior. Although there has not yet been wide use of these techniques in the motor rehabilitation field, they have great potential. In this review, I describe how the current state of machine learning can be applied to 3D kinematic analysis, and how this will have an impact on neurorehabilitation.

RECENT FINDINGS

Applications of deep learning methods, in the form of convolutional neural networks, have been revolutionary for image analysis such as face recognition and object detection in images, exceeding human level performance. Recent studies have shown applicability of these deep learning approaches to human posture and movement classification. It is to be expected that portable stereo-camera systems will bring 3D pose estimation into the clinical setting and allow the assessment of movement quality in response to interventions. Advances in machine learning can help automate the process of obtaining 3D kinematics of human movements and to identify/classify patterns of movement.

Can neuromodulation techniques optimally exploit cerebello-thalamo-cortical circuit properties to enhance motor learning post-stroke?

Individuals post-stroke sustain motor deficits years after the stroke. Despite recent advancements in the applications of non-invasive brain stimulation techniques and Deep Brain Stimulation in humans, there is a lack of evidence supporting their use for rehabilitation after brain lesions. Non-invasive brain stimulation is already in use for treating motor deficits in individuals with Parkinson's disease and post-stroke. Deep Brain Stimulation has become an established treatment for individuals with movement disorders, such as Parkinson's disease, essential tremor, epilepsy, cerebral palsy and dystonia. It has also been utilized for the treatment of Tourette's syndrome, Alzheimer's disease and neuropsychiatric conditions such as obsessive-compulsive disorder, major depression and anorexia nervosa. There exists growing scientific knowledge from animal studies supporting the use of Deep Brain Stimulation to enhance motor recovery after brain damage. Nevertheless, these results are currently not applicable to humans. This review details the current literature supporting the use of these techniques to enhance motor recovery, both from human and animal studies, aiming to encourage development in this domain.

[Modern aspects of the pathophysiology of walking disorders and their rehabilitation in post-stroke patients]

The problem of rehabilitation of post-stroke patients with motor deficit remains relevant with growing prevalence of disability and decreasing mortality, despite all measures aimed at stroke prevention and morbidity reduction. One of the most common consequences of stroke is gait impairment as a result of spastic paresis of the lower limb (decreased gait velocity, shortened step, excessive loading of intact limb etc.), which leads to significant maladaptation, increased risk of falls, decrease in quality of life. The article presents a detailed review of motor action in normal and pathologic conditions, analysis of neuronal structures involved into a movement act in healthy individuals and in stroke patients, current aspects of gait pathophysiology, characteristics of post-stroke gait (speed and asymmetry of gain, balance control impairment). A separate paragraph is devoted to gait recovery after stroke with analysis of existing and developing strategies of rehabilitation, aimed at the improvement of vertical posture, balance control and movement, condition, tone and functioning of skeletal muscles. Authors also analyze new research information on the efficacy of botulinum toxin preparations and programs of Guided Self-Rehabilitation Contracts (GSC), present the results of clinical trials demonstrating the efficacy of combination of these two methods.

Comparisons between end-effector and exoskeleton rehabilitation robots regarding upper extremity function among chronic stroke patients with moderate-to-severe upper limb impairment

End-effector (EE) and exoskeleton (Exo) robots have not been directly compared previously. The present study aimed to directly compare EE and Exo robots in chronic stroke patients with moderate-to-severe upper limb impairment. This single-blinded, randomised controlled trial included 38 patients with stroke who were admitted to the rehabilitation hospital. The patients were equally divided into EE and Exo groups. Baseline characteristics, including sex, age, stroke type, brain lesion side (left/right), stroke duration, Fugl–Meyer Assessment (FMA)–Upper Extremity score, and Wolf Motor Function Test (WMFT) score, were assessed. Additionally, impairment level (FMA, motor status score), activity (WMFT), and participation (stroke impact scale [SIS]) were evaluated. There were no significant differences in baseline characteristics between the groups. After the intervention, improvements were significantly better in the EE group with regard to activity and participation (WMFT–Functional ability rating scale, WMFT–Time, and SIS–Participation). There was no intervention-related adverse event. The EE robot intervention is better than the Exo robot intervention with regard to activity and participation among chronic stroke patients with moderate-to-severe upper limb impairment. Further research is needed to confirm this novel finding.

Stroke and potential benefits of brain-computer interface

To treat stroke and, in particular, to alleviate the personal and social burden of stroke survivors is a main challenge for neuroscience research. Advancements in the knowledge of neurobiologic mechanisms subserving stroke-related damage and recovery provide key data to guide clinicians to tailor interventions to specific patient's needs. How does the brain-computer interface (BCI) fit into this scenario? A technique created to allow completely paralyzed individuals to control the environment recently introduced a new line of development: to provide a means to possibly control formation and changes in the brain network organization. In a sort of revolution, similar to the change from geocentric to heliocentric planet organization envisioned by Copernicus, we are facing a critical change in BCI research, moving from a brain to computer direction to a computer to brain one. This direction change will profoundly open up new avenues for BCI research and clinical applications. In this chapter, we address this change and discuss present and future applications of this new line idea of BCI use in stroke.

Improvements in skilled walking associated with kinematic adaptations in people with spinal cord injury

Introduction

Individuals with motor-incomplete SCI (m-iSCI) remain limited community ambulators, partly because they have difficulty with the skilled walking requirements of everyday life that require adaptations in inter-joint coordination and range of motion of the lower limbs. Following locomotor training, individuals with SCI show improvements in skilled walking and walking speed, however there is limited understanding of how adaptations in lower limb kinematics following training contribute to improvements in walking.

Objective

To determine the relationship between changes in lower limb kinematics (range of motion and inter-joint coordination) and improvements in walking function (walking speed and skilled walking) following locomotor training.

Methods

Lower limb kinematics were recorded from 8 individuals with chronic m-iSCI during treadmill walking before and after a 3-month locomotor training program. Data were also collected from 5 able-bodied individuals to provide normative values. In individuals with SCI, muscle strength was used to define the stronger and weaker limb. Motion analysis was used to determine, hip, knee and ankle angles. Joint angle-angle plots (cyclograms) were used to quantify inter-joint coordination. Shape differences between pre-and post-training cyclograms were used to assess the changes in coordination and their relation to improvements in walking function. Walking function was assessed using the 10MWT for walking speed and the SCI-FAP for skilled walking. Comparing pre- and post-training cyclograms to the able-bodied pattern was used to understand the extent to which changes in coordination involved the recovery of normative motor patterns.

Results

Following training, improvements in skilled walking were significantly related to changes in hip-ankle coordination (ρ = − .833, p = 0.010) and knee range of motion (ρ = .833, p = 0.010) of the weaker limb. Inter-joint coordination tended to revert towards normative patterns, but not completely. No relationships were observed with walking speed.

Conclusion

Larger changes in hip-ankle coordination and a decrease in knee range of motion in the weaker limb during treadmill walking were related to improvements in skilled walking following locomotor training in individuals with SCI. The changes in coordination seem to reflect some restoration of normative patterns and the adoption of compensatory strategies, depending on the participant.

A virtual reality tool for measuring and shaping trunk compensation for persons with stroke: Design and initial feasibility testing

Background: Compensatory movement, such as flexing the trunk during reaching, may negatively affect motor improvement during task-based practice for persons with stroke. Shaping, or incrementally decreasing, the amount of compensation used during rehabilitation may be a viable strategy with methods using virtual reality.

Methods: A virtual reality tool was designed to (1) monitor upper extremity movement kinematics with an off-the-shelf motion sensor (Microsoft Kinect V2), (2) convert movements into control of widely available computer games, and (3) provide real-time feedback to shape trunk compensation. This system was tested for feasibility by a small cohort of participants with chronic stroke (n = 5) during a 1-h session involving 40 min of virtual reality interaction. Outcomes related to repetitions, compensation, movement kinematics, usability, motivation, and sense of presence were collected.

Results: Participants achieved a very high dose of reaching repetitions (461 ± 184), with an average of 81% being successful and 19% involving compensatory trunk flexion. Participants rated the system as highly usable, motivating, engaging, and safe.

Conclusions: VRShape is feasible to use as a tool for increasing repetition rates, measuring and shaping compensation, and enhancing motivation for upper extremity therapy. Future research should focus on software improvements and investigation of efficacy during a virtual reality-based motor intervention.

Toward Restoration of Normal Mechanics of Functional Hand Tasks Post-Stroke: Subject-Specific Approach to Reinforce Impaired Muscle Function

Robotic therapy enables mass practice of complex hand movements after stroke, but current devices generally enforce patients to reproduce prescribed kinematic patterns using rigid actuators, without considering individuals' unique impairment characteristics, thereby reducing their efficacy. In this paper, we tested the feasibility of a novel, theory-based "biomimetic" approach to restoring mechanics of complex hand tasks with subject-specific assistance patterns. Twelve chronic stroke survivors performed two simulated functional tasks: hand open and simulated pinch task (distal pad press). Assistance was provided by non-restraining actuators (exotendons) that counteracted 'subject-specific' impairments, identified during unassisted task performance. There was no constraint of movement to predefined patterns. Assistance patterns required to complete tasks were significantly different across subjects, reflecting high variability in impairment and required assistance patterns. For hand open, range of motion and interjoint coordination were significantly improved for severely impaired patients, while movement quality was enhanced (reduction in jerk) for those less impaired. For simulated pinch, subject-specific assistance restored task mechanics before injury, as patients were able to direct fingertip force toward the direction normal to surface; angular deviation reduced from 16.8°±10.4° to 3.7°±2.6°. Notably, electromyography data confirmed that subjects maintained an effort level under assistance comparable to unassisted conditions. The proposed method could lead to a novel paradigm for hand rehabilitation that restores complex task mechanics with a subject-specific assistance reflecting individual impairment characteristics while promoting subjects' participation.

Reduced Upper Limb Recovery in Subcortical Stroke Patients With Small Prior Radiographic Stroke

Background: Research imaging costs limit lesion-based analyses in already expensive large stroke rehabilitation trials. Despite the belief that lesion characteristics influence recovery and treatment response, prior studies have not sufficiently addressed whether lesion features are an important consideration in motor rehabilitation trial design.

Objective: Using clinically-obtained neuroimaging, evaluate how lesion characteristics relate to upper extremity (UE) recovery and response to therapy in a large UE rehabilitation trial.

Methods: We reviewed lesions from 297 participants with mild-moderate motor impairment in the Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) study and their association with motor recovery, measured by the UE Fugl-Meyer (UE-FM). Significant lesion features identified on correlational and bivariate analysis were further analyzed for associations with recovery and therapy response using longitudinal mixed models.

Results: Prior radiographic stroke was associated with less recovery on UE-FM in participants with motor impairment from subsequent subcortical stroke (−5.8 points) and in the overall sample (−3.6 points), but not in participants with cortical or mixed lesions. Lesion volume was also associated with less recovery, particularly after subcortical stroke. Every decade increase in age was associated with 1 less point of recovery on UE-FM. Response to specific treatment regimens varied based on lesion characteristics. Subcortical stroke patients experienced slightly less recovery with higher doses of upper extremity task-oriented training. Participants with cortical or mixed lesions experienced more recovery with higher doses of usual and customary therapy. Other imaging features (leukoaraiosis, ischemic vs. hemorrhagic stroke) were not significant.

Conclusions: ICARE clinical imaging revealed information useful for UE motor trial design: stratification of persons with and without prior radiographic stroke may be required in participants with subcortical stroke, the majority of motor rehabilitation trial participants. Most of the prior radiographic strokes were small and cortically-based, suggesting even minor prior brain injury remote to the acute stroke lesion may limit spontaneous and therapy-related recovery. Lesion location may be associated with response to different therapy regimens, but the effects are variable and of unclear significance.

DeepBehavior: A Deep Learning Toolbox for Automated Analysis of Animal and Human Behavior Imaging Data

Detailed behavioral analysis is key to understanding the brain-behavior relationship. Here, we present deep learning-based methods for analysis of behavior imaging data in mice and humans. Specifically, we use three different convolutional neural network architectures and five different behavior tasks in mice and humans and provide detailed instructions for rapid implementation of these methods for the neuroscience community. We provide examples of three dimensional (3D) kinematic analysis in the food pellet reaching task in mice, three-chamber test in mice, social interaction test in freely moving mice with simultaneous miniscope calcium imaging, and 3D kinematic analysis of two upper extremity movements in humans (reaching and alternating pronation/supination). We demonstrate that the transfer learning approach accelerates the training of the network when using images from these types of behavior video recordings. We also provide code for post-processing of the data after initial analysis with deep learning. Our methods expand the repertoire of available tools using deep learning for behavior analysis by providing detailed instructions on implementation, applications in several behavior tests, and post-processing methods and annotated code for detailed behavior analysis. Moreover, our methods in human motor behavior can be used in the clinic to assess motor function during recovery after an injury such as stroke.

Ergodicity Reveals Assistance and Learning from Physical Human-Robot Interaction

This paper applies information theoretic principles to the investigation of physical human-robot interaction. Drawing from the study of human perception and neural encoding, information theoretic approaches offer a perspective that enables quantitatively interpreting the body as an information channel, and bodily motion as an information-carrying signal. We show that ergodicity, which can be interpreted as the degree to which a trajectory encodes information about a task, correctly predicts changes due to reduction of a person's existing deficit or the addition of algorithmic assistance. The measure also captures changes from training with robotic assistance. Other common measures for assessment failed to capture at least one of these effects. This information-based interpretation of motion can be applied broadly, in the evaluation and design of human-machine interactions, in learning by demonstration paradigms, or in human motion analysis.

Therapeutic Systems and Technologies: State-of-the-Art Applications, Opportunities, and Challenges

In this review, we present current state-of-the-art developments and challenges in the areas of thermal therapy, ultrasound tomography, image-guided therapies, ocular drug delivery, and robotic devices in neurorehabilitation. Additionally, intellectual property and regulatory aspects pertaining to therapeutic systems and technologies are addressed.

Self-efficacy and Reach Performance in Individuals With Mild Motor Impairment Due to Stroke

BACKGROUND

Persistent deficits in arm function are common after stroke. An improved understanding of the factors that contribute to the performance of skilled arm movements is needed. One such factor may be self-efficacy (SE).

OBJECTIVE

To determine the level of SE for skilled, goal-directed reach actions in individuals with mild motor impairment after stroke and whether SE for reach performance correlated with actual reach performance.

METHODS

A total of 20 individuals with chronic stroke (months poststroke: mean 58.1 ± 38.8) and mild motor impairment (upper-extremity Fugl-Meyer [FM] motor score: mean 53.2, range 39 to 66) and 6 age-matched controls reached to targets presented in 2 directions (ipsilateral, contralateral). Prior to each block (24 reach trials), individuals rated their confidence on reaching to targets accurately and quickly on a scale that ranged from 0 ( not very confident) to 10 ( very confident).

RESULTS

Overall reach performance was slower and less accurate in the more-affected arm compared with both the less-affected arm and controls. SE for both reach speed and reach accuracy was lower for the more-affected arm compared with the less-affected arm. For reaches with the more-affected arm, SE for reach speed and age significantly predicted movement time to ipsilateral targets ( R² = 0.352), whereas SE for reach accuracy and FM motor score significantly predicted end point error to contralateral targets ( R² = 0.291).

CONCLUSIONS

SE relates to measures of reach control and may serve as a target for interventions to improve proximal arm control after stroke.

Virtual reality experiences, embodiment, videogames and their dimensions in neurorehabilitation

Background

In the context of stroke rehabilitation, new training approaches mediated by virtual reality and videogames are usually discussed and evaluated together in reviews and meta-analyses. This represents a serious confounding factor that is leading to misleading, inconclusive outcomes in the interest of validating these new solutions.

Main body

Extending existing definitions of virtual reality, in this paper I put forward the concept of virtual reality experience (VRE), generated by virtual reality systems (VRS; i.e. a group of variable technologies employed to create a VRE). Then, I review the main components composing a VRE, and how they may purposely affect the mind and body of participants in the context of neurorehabilitation. In turn, VRS are not anymore exclusive from VREs but are currently used in videogames and other human-computer interaction applications in different domains. Often, these other applications receive the name of virtual reality applications as they use VRS. However, they do not necessarily create a VRE. I put emphasis on exposing fundamental similarities and differences between VREs and videogames for neurorehabilitation. I also recommend describing and evaluating the specific features encompassing the intervention rather than evaluating virtual reality or videogames as a whole.

Conclusion

This disambiguation between VREs, VRS and videogames should help reduce confusion in the field. This is important for databases searches when looking for specific studies or building metareviews that aim at evaluating the efficacy of technology-mediated interventions.

Somatosensory Plasticity in Pediatric Cerebral Palsy following Constraint-Induced Movement Therapy

Cerebral palsy (CP) is predominantly a disorder of movement, with evidence of sensory-motor dysfunction. CIMT¹ is a widely used treatment for hemiplegic CP. However, effects of CIMT on somatosensory processing remain unclear. To examine potential CIMT-induced changes in cortical tactile processing, we designed a prospective study, during which 10 children with hemiplegic CP (5 to 8 years old) underwent an intensive one-week-long nonremovable hard-constraint CIMT. Before and directly after the treatment, we recorded their cortical event-related potential (ERP) responses to calibrated light touch (versus a control stimulus) at the more and less affected hand. To provide insights into the core neurophysiological deficits in light touch processing in CP as well as into the plasticity of this function following CIMT, we analyzed the ERPs within an electrical neuroimaging framework. After CIMT, brain areas governing the more affected hand responded to touch in configurations similar to those activated by the hemisphere controlling the less affected hand before CIMT. This was in contrast to the affected hand where configurations resembled those of the more affected hand before CIMT. Furthermore, dysfunctional patterns of brain activity, identified using hierarchical ERP cluster analyses, appeared reduced after CIMT in proportion with changes in sensory-motor measures (grip or pinch movements). These novel results suggest recovery of functional sensory activation as one possible mechanism underlying the effectiveness of intensive constraint-based therapy on motor functions in the more affected upper extremity in CP. However, maladaptive effects on the less affected constrained extremity may also have occurred. Our findings also highlight the use of electrical neuroimaging as feasible methodology to measure changes in tactile function after treatment even in young children, as it does not require active participation.

Neuromuscular synergies in motor control in normal and poststroke individuals

Muscle synergies are proposed to function as motor primitives that are modulated by frontal brain areas to construct a large repertoire of movement. This paper reviews the history of the development of our current theoretical understanding of nervous system-based motor control mechanisms and more specifically the concept of muscle synergies. Computational models of muscle synergies, especially the nonnegative matrix factorization algorithm, are discussed with specific reference to the changes in synergy control post-central nervous system (CNS) lesions. An alternative approach for motor control is suggested, exploiting a combination of synergies control or flexible muscle control used for gross motor skills and for individualized finger movements. Rehabilitation approaches, either supporting or inhibiting the use of basic movement patterns, are discussed in the context of muscle synergies. Applications are discussed for the use of advanced technologies that can promote the recovery and functioning of the human CNS after stroke.

Improved quality of life following constraint-induced movement therapy is associated with gains in arm use, but not motor improvement

BACKGROUND

Constraint-induced movement therapy (CI therapy) is one of few treatments for upper extremity (UE) hemiparesis that has been shown to result in motor recovery and improved quality of life in chronic stroke. However, the extent to which treatment-induced improvements in motor function versus daily use of the more affected arm independently contribute to improved quality of life remains largely unexplored.

OBJECTIVE

The objective of this study is to identify whether motor function or daily use of a hemiparetic arm has a greater influence on quality of life after CI therapy.

METHODS

Two cohorts of participants with chronic stroke received either in-person CI therapy (n = 29) or video-game home-based CI therapy (n = 16). The two cohorts were combined and the motor-related outcomes (Wolf Motor Function Test, Action Research Arm Test, Motor Activity Log [MAL]) and quality of life (Stroke-Specific Quality of Life) were jointly modeled to assess the associations between outcomes.

RESULTS

The only outcome associated with improved quality of life was the MAL. Improvements in quality of life were not restricted to motor domains, but generalized to psychosocial domains as well.

CONCLUSIONS

Results suggest that improved arm use during everyday activities is integral to maximizing quality of life gains during motor rehabilitation for chronic post-stroke UE hemiparesis. In contrast, gains in motor function were not associated with increases in quality of life. These findings further support the need to implement techniques into clinical practice that promote arm use during daily life if improving quality of life is a main goal of treatment. ClinicalTrials.gov Registration Numbers: NCT01725919 and NCT03005457.

Music-supported therapy for stroke motor recovery: theoretical and practical considerations

Music may confer benefits for well-being and health. What is the state of knowledge and evidence for a role of music in supporting the rehabilitation of movements after stroke? In this brief perspective, I provide background context and information about stroke recovery in general, in order to spark reflection and discussion for how we think music may impact motor recovery, given the current clinical milieu.

Neurophysiological effects of constraint-induced movement therapy and motor function: A systematic review

Background/Aims:

There is a claim that improvements in motor function in people with stroke following constraint-induced movement therapy (CIMT) is due to compensation but not actually neurorestoration. However, few studies have demonstrated improvements in neurophysiological outcomes such as increased motor map size and activation of primary cortex, or their positive correlations with motor function, following CIMT. The aim of this study was to carry out a systematic review of CIMT trials using neurophysiological outcomes, and a meta-analysis of the relationship between the neurophysiological outcomes and motor function.

Methods:

The PubMed, PEDro and CENTRAL databases, as well as the reference lists of the included studies, were searched. The included studies were randomised controlled trials comparing the effect of CIMT on neurophysiological outcomes compared with other rehabilitation techniques, conventional therapy, or another variant of CIMT. Methodological quality was assessed using the PEDro scale. The data extracted from the studies were sample size, eligibility criteria, dose of intervention and control, outcome measurements, and time since stroke.

Findings:

A total of 10 articles (n=219) fulfilled the study inclusion criteria, all of which were used for narrative synthesis, and four studies were used in the meta-analysis. The methodological quality of the studies ranged from low to high. Strong, positive, and significant correlations were found between the neurophysiological and motor function outcomes in fixed effects (z=3.268, p=0.001; r=0.52, 95% confidence interval (CI) 0.227–0.994) and random-effects (z=2.106, p=0.035; r=0.54, 95% CI 0.0424–0.827) models.

Conclusions:

Randomised controlled trials evaluating the effects of CIMT on neurophysiological outcomes are few in number. Additionally, these studies used diverse outcomes, which makes it difficult to draw any meaningful conclusion. However, there is a strong positive correlation between neurophysiological and motor function outcomes in these studies.

Predicting shoulder function after constraint-induced movement therapy: a retrospective cohort study

Background Several predictors have been associated with upper extremity (UE) recovery after stroke, but characteristics that predict shoulder function after constraint-induced movement therapy (CIMT) have not yet been identified. Objectives To identify predictors associated with satisfactory shoulder function in patients with reduced shoulder function at admission to CIMT. Methods One hundred and seventy five patients were treated using CIMT while in a specialized inpatient hospital. Satisfactory shoulder function was defined according to the functional ability scale of the Wolf Motor Function test. Predictors of satisfactory shoulder function after CIMT were identified using multivariable logistic regression. Results Better distal arm function and good proximal shoulder function on admission to CIMT were strong predictors of satisfactory shoulder function, while age and time of admission to CIMT since stroke were not. Seventeen percent of all CIMT-participants with reduced shoulder function pre-CIMT reached a level of satisfactory shoulder function after CIMT. Discussion A substantial part of patients with reduced shoulder function reached a level of satisfactory shoulder function after CIMT. Intensive CIMT training, comprising tasks that require both distal and proximal UE function, may increase shoulder function in patients with a potential functional reserve.

Progressive Abduction Loading Therapy with Horizontal-Plane Viscous Resistance Targeting Weakness and Flexion Synergy to Treat Upper Limb Function in Chronic Hemiparetic Stroke: A Randomized Clinical Trial

Background

Progressive abduction loading therapy has emerged as a promising exercise therapy in stroke rehabilitation to systematically target the loss of independent joint control (flexion synergy) in individuals with chronic moderate/severe upper-extremity impairment. Preclinical investigations have identified abduction loading during reaching exercise as a key therapeutic factor to improve reaching function. An augmentative approach may be to additionally target weakness by incorporating resistance training to increase constitutive joint torques of reaching with the goal of improving reaching function by “overpowering” flexion synergy. The objective was, therefore, to determine the therapeutic effects of horizontal-plane viscous resistance in combination with progressive abduction loading therapy.

Methods

32 individuals with chronic hemiparetic stroke were randomly allocated to two groups. The two groups had equivalent baseline characteristics on all demographic and outcome metrics including age (59 ± 11 years), time poststroke (10.1 ± 7.6 years), and motor impairment (Fugl-Meyer, 26.7 ± 6.5 out of 66). Both groups received therapy three times/week for 8 weeks while the experimental group included additional horizontal-plane viscous resistance. Quantitative standardized progression of the intervention was achieved using a robotic device. The primary outcomes of reaching distance and velocity under maximum abduction loading and secondary outcomes of isometric strength and a clinical battery were measured at pre-, post-, and 3 months following therapy.

Results

There was no difference between groups on any outcome measure. However, for combined groups, there was a significant increase in reaching distance (13.2%, effect size; d = 0.56) and velocity (13.6%, effect size; d = 0.27) at posttesting that persisted for 3 months and also a significant increase in abduction, elbow extension, and external rotation strength at posttesting that did not persist 3 months. Similarly, the clinical battery demonstrated a significant improvement in participant-reported measures of “physical problems” and “overall recovery” across all participants.

Conclusion

The strengthening approach of incorporating horizontal-plane viscous resistance did not enhance the reaching function improvements observed in both groups. Data do not support the postulation that one can be trained to “overpower” the flexion synergy with resistance training targeting constitutive joint torques of reaching. Instead, flexion synergy must be targeted with progressive abduction loading to improve reaching function.

Trial Registration

ClinicalTrials.gov, NCT01548781.

Identifying compensatory movement patterns in the upper extremity using a wearable sensor system

OBJECTIVE

Movement impairments such as those due to stroke often result in the nervous system adopting atypical movements to compensate for movement deficits. Monitoring these compensatory patterns is critical for improving functional outcomes during rehabilitation. The purpose of this study was to test the feasibility and validity of a wearable sensor system for detecting compensatory trunk kinematics during activities of daily living.

APPROACH

Participants with no history of neurological impairments performed reaching and manipulation tasks with their upper extremity, and their movements were recorded by a wearable sensor system and validated using a motion capture system. Compensatory movements of the trunk were induced using a brace that limited range of motion at the elbow.

MAIN RESULTS

Our results showed that the elbow brace elicited compensatory movements of the trunk during reaching tasks but not manipulation tasks, and that a wearable sensor system with two sensors could reliably classify compensatory movements (~90% accuracy).

SIGNIFICANCE

These results show the potential of the wearable system to assess and monitor compensatory movements outside of a lab setting.

Cell Therapy in Stroke-Cautious Steps Towards a Clinical Treatment

In the future, stroke patients may receive stem cell therapy as this has the potential to restore lost functions. However, the development of clinically deliverable therapy has been slower and more challenging than expected. Despite recommendations by STAIR and STEPS consortiums, there remain flaws in experimental studies such as lack of animals with comorbidities, inconsistent approaches to experimental design, and concurrent rehabilitation that might lead to a bias towards positive results. Clinical studies have typically been small, lacking control groups as well as often without clear biological hypotheses to guide patient selection. Furthermore, they have used a wide range of cell types, doses, and delivery methods, and outcome measures. Although some ongoing and recent trial programs offer hints that these obstacles are now being tackled, the Horizon2020 funded RESSTORE trial will be given as an example of inconsistent regulatory requirements and challenges in harmonized cell production, logistic, and clinical criteria in an international multicenter study. The PISCES trials highlight the complex issues around intracerebral cell transplantation. Therefore, a better understanding of translational challenges is expected to pave the way to more successful help for stroke patients.

Behavioral and neurophysiological mechanisms underlying motor skill learning in patients with post-stroke hemiparesis

OBJECTIVE

Given the presence of execution deficits after stroke, it is difficult to determine if patients with stroke have deficits in motor skill learning with the paretic arm. Here, we controlled for execution deficits while testing practice effects of the paretic arm on motor skill learning, long-term retention, and corticospinal excitability.

METHODS

Ten patients with unilateral stroke and ten age-matched controls practiced a kinematic arm skill for two days and returned for retention testing one-day and one-month post-practice. Motor skill learning was quantified as a change in speed-accuracy tradeoff from baseline to retention tests. Transcranial magnetic stimulation (TMS) was used to generate an input-output curve of the ipsilesional motor cortex (M1), and measure transcallosal inhibition from contralesional to ipsilesional M1.

RESULTS

While the control group had greater overall accuracy than the stroke group, both groups showed comparable immediate and long-term improvements with practice. Skill improvements were accompanied by greater excitability of the ipsilesional corticospinal system and reduced transcallosal inhibition from contralesional to ipsilesional M1.

CONCLUSIONS

When execution deficits are accounted for, patients with stroke demonstrate relatively intact motor skill learning with the paretic arm. Paretic arm learning is accompanied by modulations in corticospinal and transcallosal mechanisms.

SIGNIFICANCE

Functional recovery after stroke relies on ability for skill learning and the underlying mechanisms.

Complex Skill Training Transfers to Improved Performance and Control of Simpler Tasks After Stroke

BACKGROUND

Given limited therapy time, it is important to practice tasks that optimize transfer to other tasks that cannot be practiced during therapy. However, little is known about how tasks can be selected for practice to optimize generalization.

OBJECTIVE

One dimension of task selection is the complexity of the task. The purpose of the current study was to test if learning of a complex motor skill with the paretic arm would transfer to a simpler unpracticed goal-directed reaching task.

DESIGN

This is an observational study, repeated measures design.

METHODS

Fifteen participants with mild-to-moderate stroke practiced a complex motor skill using their paretic arm for 2 consecutive days. Complex skill learning was quantified using change in the speed-accuracy trade-off from baseline to 1 day and 1 month post-practice. Motor transfer was assessed as the change in goal-directed planar reaching performance and kinematics from 2 baselines to 1 day and 1 month post-practice. Nine additional participants with stroke were recruited as the test-alone group who only participated in the transfer tests to rule out the effects of repeated testing.

RESULTS

Practice improved the speed-accuracy trade-off for the practiced complex skill that was retained over a period of 1 month. Importantly, complex skill practice, but not repeated testing alone, improved the long-term performance and kinematics of the unpracticed simpler goal-directed planar reaching task. Improvements in the unpracticed transfer task (reaching) strongly correlated with improvements in the practiced complex motor skill.

LIMITATIONS

We did not have a comparison stroke group that practiced task-specific reaching movements.

CONCLUSIONS

Given the limited number of tasks that can be practiced during therapy, training complex tasks may have an added advantage of transfer to improved simpler task performance.