Genetic polymorphisms and post-stroke upper limb motor improvement - A systematic review and meta-analysis.

Background: Post-stroke upper limb (UL) motor improvement is associated with adaptive neuroplasticity and motor learning. Both intervention-related (including provision of intensive, variable, and task-specific practice) and individual-specific factors (including the presence of genetic polymorphisms) influence improvement. In individuals with stroke, most commonly, polymorphisms are found in Brain Derived Neurotrophic Factor (BDNF), Apolipoprotein (APOE) and Catechol-O-Methyltransferase (COMT). These involve a replacement of cystine by arginine (APOEε4) or valines by 1 or 2 methionines (BDNF:val66met, met66met; COMT:val158met; met158met). However, the implications of these polymorphisms on post-stroke UL motor improvement specifically have not yet been elucidated. Objective: Examine the influence of genetic polymorphism on post-stroke UL motor improvement. Design: Systematic Review and Meta-Analysis. Methods: We conducted a systematic search of the literature published in English language. The modified Downs and Black checklist helped assess study quality. We compared change in UL motor impairment and activity scores between individuals with and without the polymorphisms. Meta-analyses helped assess change in motor impairment (Fugl Meyer Assessment) scores based upon a minimum of 2 studies/time point. Effect sizes (ES) were quantified based upon the Rehabilitation Treatment Specification System as follows: small (0.08-0.18), medium (0.19 -0.40) and large (≥0.41). Results: We retrieved 10 (4 good and 6 fair quality) studies. Compared to those with BDNF val66met and met66met polymorphism, meta-analyses revealed lower motor impairment (large ES) in those without the polymorphism at intervention completion (0.5, 95% CI: 0.11-0.88) and at retention (0.58, 95% CI:0.06-1.11). The presence of CoMT val158met or met158met polymorphism had similar results, with lower impairment (large ES ≥1.5) and higher activity scores (large ES ranging from 0.5-0.76) in those without the polymorphism. Presence of APOEε4 form did not influence UL motor improvement. Conclusion: Polymorphisms with the presence of 1 or 2 met alleles in BDNF and COMT negatively influence UL motor improvement. Registration: https://osf.io/wk9cf/.

This research paper focuses on the impact of variations in DNA sequence in certain genes on improvement seen in the arms in people who have had a stroke. In this study, we studied the role of 3 genes previously identified as having variations in DNA sequence. The authors searched published research articles from 2000 onwards and selected articles that satisfied certain criteria. We then checked the quality of the selected papers. Next, we combined common data from same tests used to examine motor improvement in the arms to check if there was an overall effect. A total of 10 papers were found. The selected articles were either good or moderate in quality. Variations in DNA structure in 2 out of the 3 genes studied affected the ability to improve the use of the arms in daily life after a stroke. Such information can have important implications in the extent of recovery that is possible after a stroke. It can also be helpful to decide the best rehabilitation options that can be offered to help maximize their ability to use the arms after a stroke.

Responsiveness of the Reaching Performance Scale for Stroke.

OBJECTIVE: The objective of the study was to estimate the internal and external responsiveness of the Reaching Performance Scale for Stroke (RPSS) in individuals with stroke. DESIGN: Retrospective analysis of data from 4 randomized controlled trials. SETTING: Recruitment locations spanning rehabilitation centers and hospitals in Canada, Italy, Argentina, Peru, and Thailand. PARTICIPANTS: Data from 567 participants (acute to chronic stroke; N=567) were available. INTERVENTIONS: All 4 studies involved training using virtual reality for upper limb rehabilitation. MAIN OUTCOME MEASURES: RPSS and upper extremity Fugl-Meyer Assessment (FMA-UE) scores. Responsiveness was quantified for all data and across different stages of stroke. Internal responsiveness of the RPSS was quantified as effect-sizes calculated using post and preintervention change data. External responsiveness was quantified using orthogonal regressions between FMA-UE and RPSS scores. The area under the Receiver Operating Characteristic curve (AUC) was quantified based on the ability of RPSS scores to detect change above FMA-UE minimal clinically important different values across different stages of stroke. RESULTS: The RPSS had high internal responsiveness overall and across the acute or subacute and chronic stages of stroke. For external responsiveness, orthogonal regression analyses indicated that change in FMA-UE scores had positive moderate correlations with both RPSS Close and Far Target scores for all data and across the acute or subacute and chronic stages of stroke (0.6

A Systematic Review on the Effects of Acute Aerobic Exercise on Neurophysiological, Molecular, and Behavioral Measures in Chronic Stroke.

BACKGROUND: A single bout of aerobic exercise (AE) can produce changes in neurophysiological and behavioral measures in healthy individuals and those with stroke. However, the effects of AE-priming effects on neuroplasticity markers and behavioral measures are unclear. OBJECTIVES: This systematic review aimed to examine the effects of AE on neuroplasticity measures, such as corticomotor excitability (CME), molecular markers, cortical activation, motor learning, and performance in stroke. METHODS: A literature search was performed in MEDLINE, CINAHL, Scopus, and PsycINFO databases. Randomized and non-randomized studies incorporating acute AE in stroke were selected. Two reviewers independently assessed the risk of bias and methodological rigor of the studies and extracted data on participant characteristics, exercise interventions, and neuroplasticity related outcomes. The quality of transcranial magnetic stimulation reported methods was assessed using a standardized checklist. RESULTS: A total of 16 studies were found suitable for inclusion. Our findings suggest mixed evidence for the effects of AE on CME, limited to no effects on intracortical inhibition and facilitation and some evidence for modulating brain derived neurotrophic factor levels, motor learning, and cortical activation. Exercise intensities in the moderate to vigorous range showed a trend towards better effects on neuroplasticity measures. CONCLUSION: It appears that choosing a moderate to vigorous exercise paradigm for at least 20 to 30 minutes may induce changes in some neuroplasticity parameters in stroke. However, these findings necessitate prudent consideration as the studies were diverse and had moderate methodological quality. There is a need for a consensus on an exercise priming paradigm and for good-quality, larger controlled studies.

Virtual reality interventions to enhance upper limb motor improvement after a stroke: commonly used types of platform and outcomes.

INTRODUCTION: Virtual Reality (VR) based platforms are useful in enhancing post-stroke sub-optimal upper limb (UL) motor improvement. A variety of options are available from expensive highly customizable platforms to low cost turnkey solutions. Clinical outcomes primarily help assess the effects of VR-based platforms. These outcomes mainly quantify how much improvement has occurred. Very few outcomes characterize the type (i.e. how) of recovery. We categorized the types of VR-based platforms and outcome measures commonly used for post-stroke UL motor improvement. METHODS: We reviewed the published literature in English from 2000-2019. Different types of VR-based platforms were grouped into those available commercially and those developed by the various research groups. We initially classified outcomes from the retrieved studies under the appropriate International Classification of Functioning categories. Then, we divided the outcomes as those quantifying the type or extent of improvement. RESULTS: We found a total of 125 studies. Majority of the studies used commercially available platforms. A total of 42 different outcome measures were used. Seventeen different outcomes were used to assess body structure and functions as well as in activity limitations. Eight outcomes assessed the effects of contextual factors and participation restrictions. The Fugl Meyer Assessment, Wolf Motor Function Test and Stroke Impact Scale were most often used across the three categories. Of the 125 studies, 52 used outcomes characterizing the type of recovery. Although a smaller proportion, 24 studies included movement patterns outcomes. CONCLUSION: A standardized set of outcomes can promote better comparisons between studies using different VR-based platforms for post-stroke UL motor improvement.Implications for RehabilitationA wide variety of commercially available systems are present from expensive customizable systems to low-cost turnkey systems.The Fugl-Meyer Assessment and Wolf Motor Function Test along with the Stroke Impact Scale-Social Participation subscale were used most often across all studies as assessments of body structure and function, activity limitations and participation restriction.It is essential to include movement pattern outcomes addressing whether recovery of compensation occurs with the use of VR-based platforms.

Reaching performance scale for stroke - Test-retest reliability, measurement error, concurrent and discriminant validity.

INTRODUCTION: Post-stroke upper limb motor improvement can be better quantified by describing movement patterns characterizing movement quality and use of compensations. Movement patterns can be described using both kinematic and clinical outcomes. One clinical outcome that assesses movement quality and compensations used for reaching a Close (18 points) and Far target (18 points) is the Reaching Performance Scale for Stroke (RPSS). OBJECTIVE: To estimate the pilot test-retest reliability and validity (concurrent, discriminant) of the RPSS in individuals with chronic stroke. DESIGN: Retrospective data analysis. SETTING: Research laboratory. PARTICIPANTS: Seventy-two individuals with upper limb hemiparesis ≥6 months prior to participation. INTERVENTION: Not applicable. MAIN OUTCOME MEASURE: RPSS Close and Far Target scores. Intraclass correlation coefficients (ICCs) helped assess pilot test-retest reliability on a subset of 14 participants. Concurrent validity was assessed for individual RPSS items with corresponding kinematic outcomes (trunk displacement, shoulder flexion, shoulder horizontal adduction, elbow extension, trajectory straightness) using Pearson correlations. We also ran multiple regression analyses with the RPSS total scores and used kinematic outcomes as the criterion standard. Logistic regression analyses estimated discriminant validity. We divided participants into two groups based on the Fugl-Meyer Assessment (FMA) scores (mild: ≥50/66; moderate-to-severe: ≤49/66). RESULTS: Test-retest reliability was excellent for Close (ICC = 0.98, 95% confidence interval [CI] 0.94-0.99) and Far targets (ICC = 0.98, 95% CI 0.95-0.99). Individual RPSS items for both targets were mildly to moderately correlated with corresponding kinematic values. A combination of trajectory straightness, elbow extension, and trunk displacement explained the majority of the variance in RPSS scores (47%) for both targets. The RPSS scores discriminated between individuals with mild and moderate-to-severe motor impairment for both Close (ExpB = 3.33, P < .001; 95% CI 1.70-6.52) and Far targets (ExpB = 2.59, P < .001, 95% CI 1.65-4.07). Cutoff points for transition between groups were 15.5 (Close target) and 14 (Far target). CONCLUSION: The RPSS is a valid clinical measure with excellent pilot results of test-retest reliability for assessing movement patterns and compensations used for reaching.

Upper Limb Motor Improvement after Traumatic Brain Injury: Systematic Review of Interventions.

BACKGROUND: Traumatic brain injury (TBI) is a leading cause of adult morbidity and mortality. Individuals with TBI have impairments in both cognitive and motor domains. Motor improvements post-TBI are attributable to adaptive neuroplasticity and motor learning. Majority of the studies focus on remediation of balance and mobility issues. There is limited understanding on the use of interventions for upper limb (UL) motor improvements in this population. OBJECTIVE: We examined the evidence regarding the effectiveness of different interventions to augment UL motor improvement after a TBI. METHODS: We systematically examined the evidence published in English from 1990-2020. The modified Downs and Black checklist helped assess study quality (total score: 28). Studies were classified as excellent: 24-28, good: 19-23, fair: 14-18, and poor: ≤13 in quality. Effect sizes helped quantify intervention effectiveness. RESULTS: Twenty-three studies were retrieved. Study quality was excellent (n = 1), good (n = 5) or fair (n = 17). Interventions used included strategies to decrease muscle tone (n = 6), constraint induced movement therapy (n = 4), virtual reality gaming (n = 5), non-invasive stimulation (n = 3), arm motor ability training (n = 1), stem cell transplant (n = 1), task-oriented training (n = 2), and feedback provision (n = 1). Motor impairment outcomes included Fugl-Meyer Assessment, Modified Ashworth Scale, and kinematic outcomes (error and movement straightness). Activity limitation outcomes included Wolf Motor Function Test and Motor Activity Log (MAL). Effect sizes for majority of the interventions ranged from medium (.5-.79) to large (≥.8). Only ten studies included retention testing. CONCLUSION: There is preliminary evidence that using some interventions may enhance UL motor improvement after a TBI. Answers to emergent questions can help select the most appropriate interventions in this population.

Development and feasibility testing of action observation training videos in acute stroke survivors: Preliminary findings.

Background: Action observation training (AOT) is used for lower limb (LL) stroke rehabilitation in subacute and chronic stages, but concise information regarding the types of activities to be used and the feasibility of administration in the acute stroke population is unknown. The aim of this study was to develop and validate videos of appropriate activities for LL AOT and test administrative feasibility in acute stroke.   Method: A video inventory of LL activities was created after a literature survey and expert scrutiny. Five stroke rehabilitation experts validated the videos per domains of relevance, comprehension, clarity, camera position and brightness. LL AOT was then tested on ten individuals with acute stroke for uncovering barriers for clinical use in a feasibility study. Participants watched the activities and attempted imitation of the same. Determination of administrative feasibility was undertaken via participant interviews.   Results: Suitable LL activities for stroke rehabilitation were identified. Content validation of videos led to improvements in selected activities and video quality. Expert scrutiny led to further video processing to include different perspectives of view and speeds of projected movements. Barriers identified included inability to imitate actions shown in videos and increased distractibility for some participants.    Conclusion: A video catalogue of LL activities was developed and validated. AOT was deemed safe and feasible for acute stroke rehabilitation and may be used in future research and clinical practice.

Integration of Motor Learning Principles Into Virtual Reality Interventions for Individuals With Cerebral Palsy: Systematic Review.

BACKGROUND: Increasing evidence supports the use of virtual reality systems to improve upper limb motor functions in individuals with cerebral palsy. While virtual reality offers the possibility to include key components to promote motor learning, it remains unclear if and how motor learning principles are incorporated into the development of rehabilitation interventions using virtual reality. OBJECTIVE: The objective of this study was to determine the extent to which motor learning principles are integrated into virtual reality interventions targeting upper limb function in individuals with cerebral palsy. METHODS: A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The search was performed in 10 databases using a combination of keywords related to cerebral palsy, virtual reality, video games, and rehabilitation. Studies were divided into 2 categories: commercial video game platforms and devices and custom virtual reality systems. Study quality was assessed using the modified Downs and Black checklist. RESULTS: The initial search yielded 1497 publications. A total of 26 studies from 30 publications were included, with most studies classified as "fair" according to the modified Downs and Black checklist. The majority of studies provided enhanced feedback and variable practice and used functionally relevant and motivating virtual tasks. The dosage varied greatly (total training time ranged from 300 to 3360 minutes), with only 6 studies reporting the number of movement repetitions per session. The difficulty progression and the assessment of skills retention and transfer were poorly incorporated, especially for the commercial video games. CONCLUSIONS: Motor learning principles should be better integrated into the development of future virtual reality systems for optimal upper limb motor recovery in individuals with cerebral palsy. TRIAL REGISTRATION: PROSPERO International Prospective Register of Systematic Reviews CRD42020151982; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020151982.

Deficits in corticospinal control of stretch reflex thresholds in stroke: Implications for motor impairment.

OBJECTIVES: The corticospinal system (CS) regulates muscle activation through shifts in muscle-level tonic stretch-reflex thresholds (TSRT). This ability is impaired in stroke and contributes to sensorimotor impairments such as spasticity. We determined the role of CS in elbow flexor activity regulation in healthy and post-stroke subjects. We also determined whether CS modulation deficits were related to sensorimotor impairment intensity in post-stroke individuals. METHODS: Seventeen healthy (59.8 ± 12.2 yr) and 27 stroke subjects (58.7 ± 10.1 yr) had transcranial magnetic stimulation (TMS) applied over the primary motor cortex (M1) flexor representation to elicit motor-evoked potentials (MEPs) in elbow flexors in different angular positions. In a subset of post-stroke subjects (n = 12), flexor TSRTs were measured in passive and active conditions, and TSRT modulation was determined. RESULTS: Position-related MEP amplitude modulation was similar in healthy and mild stroke subjects, while subjects with more severe stroke exhibited less consistent modulation. MEP modulation in stroke was related to clinical upper limb motor impairment, spasticity, and the ability to modulate TSRTs between passive and active elbow movements. CONCLUSIONS: CS output was closely related to TSRT modulation. Impairments in TSRT regulation may underlie motor deficits in moderate-to-severe post-stroke individuals. SIGNIFICANCE: Translation of these neurophysiological findings to clinical applications may enhance post-stroke motor recovery.

Correction to: The effects of regenerative injection therapy compared to corticosteroids for the treatment of lateral Epicondylitis: a systematic review and meta-analysis.

[This corrects the article DOI: 10.1186/s40945-019-0063-6.].

Motor-Equivalent Intersegmental Coordination Is Impaired in Chronic Stroke.

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

The effects of regenerative injection therapy compared to corticosteroids for the treatment of lateral Epicondylitis: a systematic review and meta-analysis.

BACKGROUND: The lateral epicondyle is a common site for chronic tendinosis (i.e. lateral epicondylitis), a condition characterized by overuse and degeneration of a tendon due to repeated microtrauma. This leads to pain and functional limitations. There is a growing interest in non-surgical forms of treatment for this condition including provision of corticosteroid injections and regenerative injection therapy (provision of autologous blood and platelet rich plasma injections). OBJECTIVE: We compared the effectiveness of corticosteroids with regenerative injection therapy for the treatment of lateral epicondylitis. METHODS: We systematically reviewed randomized controlled trials published in English language from 2008 to 2018. Databases used included PEDro, Scopus, PubMed, and CINAHL. Nine articles met our selection criteria. The PEDRo scale scores helped assess study quality. Cochrane risk of bias criteria helped assess bias. We analyzed results focusing on pain and function using meta-analyses. RESULTS: Six out of 9 studies had low risk of bias. There were no short-term (1 and 2 month) differences in pain scores between the corticosteroid and regenerative injection groups. Participants receiving regenerative injections demonstrated greater long-term improvements lasting for a period of ≈2 years. CONCLUSION: Regenerative injections provision results in greater long-term pain relief and improved function for people with lateral epicondylitis.

Attitudes of Physical Therapy Students Toward the Population Currently Experiencing Homelessness: A Pilot Study.

Homelessness is a national epidemic and individuals experiencing homelessness have decreased access to healthcare services. At the same time, physical therapy (PT) educational programs are required to teach students about cultural competence, pro-bono service, and advocacy for underserved populations. Having PT students provide pro-bono services to this population in a supervised environment is a mutually beneficial scenario for the patients, students, and the PT program. AIMS: The study objective was to evaluate whether participating in a student-run free clinic (SRFC) at a homeless shelter could change PT students' attitudes towards individuals experiencing homelessness. METHODS: Forty DPT students completed the Health Professionals' Attitude Toward the Homeless Inventory (HPATHI) with 19 volunteering (experimental group) to participate in the SRFC. The HPATHI was administered again immediately following participation in the SRFC to assess if their attitudes had changed. RESULTS: Baseline scores differed between the control and experimental group (p=0.03). However, post-scores of the experimental group did not differ compared to pre-scores. The subsequent analysis estimated differences on 4 of 19 questions, specifically within the personal advocacy and social advocacy subscales. CONCLUSIONS: Overall, PT students' attitudes did not change significantly after one session of volunteering at an SRFC in a homeless shelter. However, small changes were seen in personal and social advocacy subscales of the HPATHI.

Virtual Reality and Noninvasive Brain Stimulation in Stroke: How Effective Is Their Combination for Upper Limb Motor Improvement?-A Meta-Analysis.

BACKGROUND: Efforts to augment post-stroke upper limb (UL) motor improvement include the use of newer interventions such as noninvasive brain stimulation (NIBS) and task practice in virtual reality environments (VEs). Despite increasing interest in using a combination of these 2 interventions, the effectiveness of this combination to enhance UL motor improvement outcomes has not been examined. OBJECTIVE: To evaluate the effectiveness of a combination of NIBS and task practice in a VE to augment post-stroke UL motor improvement. METHODS: We conducted a systematic search of the published literature using standard methodology. The Down and Black checklist and the Physiotherapy Evidence Database Research Organization Scale were used to assess study quality. We compared changes in UL impairment and activity levels between active stimulation and sham or other interventions using standardized mean differences and derived a summary effect size. RESULTS: We retrieved 5 studies that examined the role of a combination of NIBS and task practice in a VE to optimize UL motor improvement. These 5 studies included 3 randomized controlled trials, 1 cross-sectional study, and 1 crossover study. There was level 1a evidence that the combination was beneficial in subacute stroke. There was level 1b evidence that provision of real stimulation was not superior to sham stimulation in chronic stroke. Effect sizes favoring the combination were moderate for improvements in UL impairment and small for activity levels. CONCLUSIONS: Preliminary evidence supports the effectiveness of this combination in subacute stroke. Emergent questions need to be addressed to derive maximum benefit of this combination to augment post-stroke UL motor improvement. LEVEL OF EVIDENCE: I.

Spasticity may obscure motor learning ability after stroke.

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

Referent control of the orientation of posture and movement in the gravitational field.

This study addresses the question of how posture and movement are oriented with respect to the direction of gravity. It is suggested that neural control levels coordinate spatial thresholds at which multiple muscles begin to be activated to specify a referent body orientation (RO) at which muscle activity is minimized. Under the influence of gravity, the body is deflected from the RO to an actual orientation (AO) until the emerging muscle activity and forces begin to balance gravitational forces and maintain body stability. We assumed that (1) during quiet standing on differently tilted surfaces, the same RO and thus AO can be maintained by adjusting activation thresholds of ankle muscles according to the surface tilt angle; (2) intentional forward body leaning results from monotonic ramp-and-hold shifts in the RO; (3) rhythmic oscillation of the RO about the ankle joints during standing results in body swaying. At certain sway phases, the AO and RO may transiently overlap, resulting in minima in the activity of multiple muscles across the body. EMG kinematic patterns of the 3 tasks were recorded and explained based on the RO concept that implies that these patterns emerge due to referent control without being pre-programmed. We also confirmed the predicted occurrence of minima in the activity of multiple muscles at specific body configurations during swaying. Results re-affirm previous rejections of model-based computational theories of motor control. The role of different descending systems in the referent control of posture and movement in the gravitational field is considered.

Depressive symptoms influence use of feedback for motor learning and recovery in chronic stroke.

PURPOSE: Sensorimotor impairments and depressive symptoms (PSD) influence arm motor recovery post-stroke. Feedback provision improves upper limb motor learning in patients with chronic stroke but factors including PSD may affect ability to use feedback. We evaluated the influence of PSD on the ability to use auditory feedback for upper limb recovery and motor learning in patients with chronic stroke. METHODS: Participants (n = 24) practiced 72 pointing movements/session (6 targets, 12 sessions, randomized) with auditory feedback on movement speed and trunk displacement. The presence of PSD (Beck's Depression Inventory; BDI-II) was assessed at pre-intervention (PRE). Arm motor impairment (Fugl-Meyer Assessment, shoulder horizontal adduction, shoulder flexion, elbow extension ranges, trunk displacement) and arm use (Motor Activity Log) were assessed at PRE, immediately after (POST) and retention (3 mos; RET). Participants were divided into two groups based on BDI-II scores: ≥ 14/63 (DEP group; n = 8; score: 20.5 ± 7.5) and ≤ 13/63 (no PSD (ND) group; n = 16; score: 5.0 ± 3.8). Changes in impairment and arm use levels were assessed (mixed-model ANOVAs). RESULTS: All participants improved arm use. DEP had lower Fugl-Meyer scores, used more compensatory trunk displacement and had lower shoulder horizontal adduction range compared to ND. CONCLUSION: The presence of PSD diminished the ability to use auditory feedback for arm motor recovery and motor learning.

Emerging evidence of the association between cognitive deficits and arm motor recovery after stroke: A meta-analysis.

PURPOSE: Motor and cognitive impairments are common and often coexist in patients with stroke. Although evidence is emerging about specific relationships between cognitive deficits and upper-limb motor recovery, the practical implication of these relationships for rehabilitation is unclear. Using a structured review and meta-analyses, we examined the nature and strength of the associations between cognitive deficits and upper-limb motor recovery in studies of patients with stroke. METHODS: Motor recovery was defined using measures of upper limb motor impairment and/or activity limitations. Studies were included if they reported on at least one measure of cognitive function and one measure of upper limb motor impairment or function. RESULTS: Six studies met the selection criteria. There was a moderate association (r = 0.43; confidence interval; CI:0.09- 0.68, p = 0.014) between cognition and overall arm motor recovery. Separate meta-analyses showed a moderately strong association between executive function and motor recovery (r = 0.48; CI:0.26- 0.65; p < 0.001), a weak positive correlation between attention and motor recovery (r = 0.25; CI:0.04- 0.45; p = 0.023), and no correlation between memory and motor recovery (r = 0.42; CI:0.16- 0.79; p = 0.14). CONCLUSION: These results imply that information on the presence of cognitive deficits should be considered while planning interventions for clients in order to design more personalized interventions tailored to the individual for maximizing upper-limb recovery.

Arm motor recovery using a virtual reality intervention in chronic stroke: randomized control trial.

INTRODUCTION: Despite interest in virtual environments (VEs) for poststroke arm motor rehabilitation, advantages over physical environment (PE) training have not been established. OBJECTIVE: The authors compared kinematic and clinical outcomes of dose-matched upper-limb training between a 3D VE and a PE in chronic stroke. METHODS: Participants (n = 32) were randomized to a 3D VE or PE for training. They pointed to 6 workspace targets (72 trials, 12 trials/target, randomized) for 12 sessions over 4 weeks with similar feedback on precision, movement speed, and trunk displacement. Primary (kinematics, clinical arm motor impairment) and secondary (activity level, arm use) outcomes were compared by time (PRE, POST, and follow-up, RET), training environment, and impairment severity (mild, moderate-to-severe) using mixed-model analyses of variance (ANOVAs). RESULTS: Endpoint speed, overall performance on a reach-to-grasp task, and activity levels increased in both groups. Only participants in the VE group improved shoulder horizontal adduction at POST (9.5°) and flexion at both POST (6.3°) and RET (13°). Impairment level affected outcomes. After VE training, the mild group increased elbow extension (RET, 25.5°). The moderate-to-severe group in VE increased arm use at POST (0.5 points) and reaching ability at RET (2.2 points). The moderate-to-severe group training in PE increased reaching ability earlier (POST, 1.7 points) and both elbow extension (10.7°) and arm use (0.4 points) at RET, but these changes were accompanied by increased compensatory trunk displacement (RET, 30.2 mm). CONCLUSION: VE training led to more changes in the mild group and a motor recovery pattern in the moderate-to-severe group indicative of less compensation, possibly because of a better use of feedback.