Less-affected Limb Research Articles

Differences in brain activation and connectivity during unaffected hand exercise in subacute and convalescent stroke patients

Patients experiencing severe hemiplegia following a stroke struggle to rehabilitate their affected limbs. Cross-education (CE) training emerges as a promising rehabilitation method due to its safety, simplicity, low risk, and ability to effectively improve muscle strength in the affected limb. However, controversy surrounds the neural mechanisms and clinical applications of CE. To address this, we employed functional near-infrared spectroscopy to monitor the response of regions of interest (ROI) and functional connectivity in patients with stroke experiencing severe hemiplegia during one session of 50% maximal voluntary contraction (MVC) strength training with less-affected hand in both subacute and convalescent phases. Our objective was to compare the two stroke groups to gain insight into the potential utility for unilateral training of the less-affected limb as an effective rehabilitation approach during different phases post of stroke.The findings revealed varying degrees of activation in the ROIs within the affected hemisphere across both groups during the task. Additionally, we found that the subacute stroke patients with severe hemiplegia (SPS) had higher blood oxygen levels in the ipsilesional primary motor (iM1), ipsilesional pre-motor and supplementary motor area (iP-SMA) and contralesional P-SMA (cP-SMA). Functional connectivity strength between the iM1 and contralesional brain regions, as well as between the iP-SMA and ipsilesional ROIs, showed statistically significant differences in SPS compared to convalescent stroke patients with severe hemiplegia (CPS) during a 50% MVC strength training session using the less-affected hand. Significance statementExploring the neural mechanisms underlying one session of 50% MVC strength training with less-affected hand sheds light on a safe therapy. The study enhances our understanding of less-affected hand training and investigates the feasibility as a future rehabilitation approach. Analyzing how one session of 50% MVC strength training with less-affected hand affects brain activation and connectivity could lead to more tailored and effective rehabilitation strategies.

Unraveling stroke gait deviations with movement analytics, more than meets the eye: a case control study.

This study aimed to identify and quantify the kinematic and kinetic gait deviations in post-stroke hemiplegic patients with matched healthy controls using Statistical Parametric Mapping (SPM). Fifteen chronic stroke patients [4 females, 11 males; age 53.7 (standard deviation 12.2) years; body mass 65.4 (10.4) kg; standing height 168.5 (9.6) cm] and 15 matched healthy controls [4 females, 11 males; age 52.9 (11.7) years; body weight 66.5 (10.7) years; standing height 168.3 (8.8) cm] were recruited. In a 10-m walking task, joint angles, ground reaction forces (GRF), and joint moments were collected, analyzed, and compared using SPM for an entire gait cycle. Generally, when comparing the stroke patients' affected (hemiplegic) and less-affected (contralateral) limbs with the control group, SPM identified significant differences in the late stance phase and early swing phase in the joint angles and moments in bilateral limbs (all p < 0.005). In addition, the vertical and anteroposterior components of GRF were significantly different in various periods of the stance phase (all p < 0.005), while the mediolateral component showed no differences between the two groups. SPM was able to detect abnormal gait patterns in both the affected and less-affected limbs of stroke patients with significant differences when compared with matched controls. The findings draw attention to significant quantifiable gait deviations in the less-affected post-stroke limb with the potential impact to inform gait retraining strategies for clinicians and physiotherapists.

A metric for characterizing the arm nonuse workspace in poststroke individuals using a robot arm.

An overreliance on the less-affected limb for functional tasks at the expense of the paretic limb and in spite of recovered capacity is an often-observed phenomenon in survivors of hemispheric stroke. The difference between capacity for use and actual spontaneous use is referred to as arm nonuse. Obtaining an ecologically valid evaluation of arm nonuse is challenging because it requires the observation of spontaneous arm choice for different tasks, which can easily be influenced by instructions, presumed expectations, and awareness that one is being tested. To better quantify arm nonuse, we developed the bimanual arm reaching test with a robot (BARTR) for quantitatively assessing arm nonuse in chronic stroke survivors. The BARTR is an instrument that uses a robot arm as a means of remote and unbiased data collection of nuanced spatial data for clinical evaluations of arm nonuse. This approach shows promise for determining the efficacy of interventions designed to reduce paretic arm nonuse and enhance functional recovery after stroke. We show that the BARTR satisfies the criteria of an appropriate metric for neurorehabilitative contexts: It is valid, reliable, and simple to use.

Task-dependent alteration of beta-band intermuscular coherence is associated with ipsilateral corticospinal tract excitability.

Beta-band (15-30 Hz) synchronization between the EMG signals of active limb muscles can serve as a non-invasive assay of corticospinal tract integrity. Tasks engaging a single limb often primarily utilize one corticospinal pathway, although bilateral neural circuits can participate in goal-directed actions involving multi-muscle coordination and utilization of feedback. Suboptimal utilization of such circuits after CNS injury can result in unintended mirror movements and activation of pathological synergies. Accordingly, it is important to understand how the actions of one limb (e.g., a less-affected limb after strokes) influence the opposite corticospinal pathway for the rehabilitation target. Certain unimanual actions decrease the excitability of the "unengaged" corticospinal tract, presumably to prevent mirror movement, but there is no direct way to predict the extent to which this will occur. In this study, we tested the hypothesis that task-dependent changes in beta-band drives to muscles of one hand will inversely correlate with changes in the opposite corticospinal tract excitability. Ten participants completed spring pinching tasks known to induce differential 15-30 Hz drive to muscles. During compressions, transcranial magnetic stimulation single pulses to the ipsilateral M1 were delivered to generate motor-evoked potentials in the unengaged hand. The task-induced changes in ipsilateral corticospinal excitability were inversely correlated with associated changes in EMG-EMG coherence of the task hand. These results demonstrate a novel connection between intermuscular coherence and the excitability of the "unengaged" corticospinal tract and provide a springboard for further mechanistic studies of unimanual tasks of varying difficulty and their effects on neural pathways relevant to rehabilitation.

Kinesiology taping and ankle foot orthosis equivalent therapeutic effects on gait function in stroke patients with foot drop: A preliminary study.

An ankle foot orthosis (AFO) is a standard type of orthosis applied to immediately treat foot drop symptoms. Kinesiology taping (KT) is a therapeutic method used in patients with neurological diseases, such as stroke, as well as in patients after orthopedic and sports injuries. This study aimed to compare outcomes of AFO treatment with those of KT to investigate the effect on gait ability in patients with foot drop after stroke. We recruited 18 patients exhibiting foot drop from stroke. Gait ability was assessed under 2 conditions: treatment with KT and that with AFO using the GAITRite system according to the following parameters: cadence, velocity, swing time, stance time, step length, and stride length. As a result, gait ability after treatment with KT and that after treatment with AFO showed no significant differences in cadence (P = .851), velocity (P = .865), swing time (P = .289 and .123), stance time (P = .255 and .711), step length (P = .955 and .975), and stride length (P = .711 and .690) of the affected and less-affected limbs. This study demonstrated that KT and AFO use have similar effects on gait function in patients with foot drop after stroke. Thus, treatment of foot drop with KT may be an alternative in patients for whom AFO use is contraindicated.

A new framework for analysis of three-dimensional shape and architecture of human skeletal muscles from in vivo imaging data.

A new framework is presented for comprehensive analysis of the three-dimensional shape and architecture of human skeletal muscles from magnetic resonance and diffusion tensor imaging data. The framework comprises three key features: 1) identification of points on the surface of and inside a muscle that have a correspondence to points on and inside another muscle, 2) reconstruction of average muscle shape and average muscle fiber orientations, and 3) utilization of data on between-muscle variation to visualize and make statistical inferences about changes or differences in muscle shape and architecture. The general use of the framework is demonstrated by its application to three case studies. Analysis of data obtained before and after 8 wk of strength training revealed there was little regional variation in hypertrophy of the vastus medialis and vastus lateralis and no systematic change in pennation angle. Analysis of passive muscle lengthening revealed heterogeneous changes in shape of the medial gastrocnemius and confirmed the ability of the methods to detect subtle changes in muscle fiber orientation. Analysis of the medial gastrocnemius of children with unilateral cerebral palsy showed that muscles in the more-affected limb were shorter, thinner, and less wide than muscles in the less-affected limb and had slightly more pennate muscle fibers in the central and proximal part of the muscle. Among other applications, the framework can be used to explore the mechanics of muscle contraction, investigate adaptations of muscle architecture, build anatomically realistic computational models of skeletal muscles, and compare muscle shape and architecture between species.NEW & NOTEWORTHY Muscle architecture is conventionally measured using simple scalar metrics such as muscle volume and average fascicle lengths. Here, a new framework is proposed for analysis of complex changes in three-dimensional architecture of whole human muscles from magnetic resonance and diffusion tensor imaging data. The general use of the framework is demonstrated through visualization, quantification, and statistical analysis of the effect of strength training, passive lengthening and cerebral palsy on three-dimensional muscle shape and architecture.

Ipsilesional Motor Cortex Activation with High-force Unimanual Handgrip Contractions of the Less-affected Limb in Participants with Stroke

Stroke is a leading cause of severe disability that often presents with unilateral motor impairment. Conventional rehabilitation approaches focus on motor practice of the affected limb and aim to suppress brain activity in the contralesional hemisphere. Conversely, exercise of the less-affected limb promotes contralesional brain activity which is typically viewed as contraindicated in stroke recovery due to the interhemispheric inhibitory influence onto the ipsilesional hemisphere. Yet, high-force unimanual handgrip contractions are known to increase ipsilateral brain activation in control participants, and it remains to be determined if high-force contractions with the less-affected limb would promote ipsilateral brain activation in participants with stroke (i.e., the ipsilesional hemisphere). Therefore, this study aimed to determine how parametric increases in handgrip force during repeated contractions with the less-affected limb impacts brain activity bilaterally in participants with stroke and in a cohort of neurologically intact controls. Participants performed repeated submaximal contractions at 25%, 50%, and 75% of their maximum voluntary contraction during separate functional magnetic resonance imaging brain scans. Brain activation during the tasks was quantified as the percent change from resting levels. In this study, higher force contractions were found to increase brain activation in the ipsilesional (stroke)/ipsilateral (controls) hemisphere in both groups (p = .002), but no between group differences were observed. These data suggest that high-force exercise with the less-affected limb may promote ipsilesional cortical plasticity to promote motor recovery of the affected-limb in participants with stroke.

Pilot test of dosage effects in HEXORR II for robotic hand movement therapy in individuals with chronic stroke.

Impaired use of the hand in functional tasks remains difficult to overcome in many individuals after a stroke. This often leads to compensation strategies using the less-affected limb, which allows for independence in some aspects of daily activities. However, recovery of hand function remains an important therapeutic goal of many individuals, and is often resistant to conventional therapies. In prior work, we developed HEXORR I, a robotic device that allows practice of finger and thumb movements with robotic assistance. In this study, we describe modifications to the device, now called HEXORR II, and a clinical trial in individuals with chronic stroke. Fifteen individuals with a diagnosis of chronic stroke were randomized to 12 or 24 sessions of robotic therapy. The sessions involved playing several video games using thumb and finger movement. The robot applied assistance to extension movement that was adapted based on task performance. Clinical and motion capture evaluations were performed before and after training and again at a 6-month followup. Fourteen individuals completed the protocol. Fugl-Meyer scores improved significantly at the 6 month time point compared to baseline, indicating reductions in upper extremity impairment. Flexor hypertonia (Modified Ashworth Scale) also decreased significantly due to the intervention. Motion capture found increased finger range of motion and extension ability after the intervention that continued to improve during the followup period. However, there was no change in a functional measure (Action Research Arm Test). At the followup, the high dose group had significant gains in hand displacement during a forward reach task. There were no other significant differences between groups. Future work with HEXORR II should focus on integrating it with functional task practice and incorporating grip and squeezing tasks.Trial Registration: ClinicalTrials.gov, NCT04536987. Registered 3 September 2020 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT04536987.

Effects of elastic neutral ankle-foot orthoses on 3 dimensional parameters during gait training in patients with stroke: A pilot study

BackgroundGeneral ankle-foot orthosis (AFO) cannot be flexibly adjusted to volumetric change in the lower leg because the molding is custom-fit. Thus, we developed a flexible assistive device called elastic neutral AFO (EN-AFO) to help stroke patients hold a neutral ankle position. The purpose of this study was to investigate the effects of EN-AFO and improve gait patterns in stroke patients with rearfoot varus deformity. MethodsFifteen stroke patients with a varus deformity of the foot performed a walking test with and without the use of EN-AFO. Kinematic data were measured with a 3D motion analysis system with inertial measurement unit (IMU) sensors. ResultsIn the stance phase, maximal pelvic tilt and maximal ankle dorsiflexion in the affected side changed, and maximal and minimal pelvic tilts and maximal hip abduction in the less-affected limb effectively changed, as well. During the swing phase, minimal pelvic tilt and minimal ankle abduction in the affective limb greatly changed; particularly, the reduction of maximal ankle inversion was significantly cleared. ConclusionsThe EN-AFO was effective in controlling the tendency of foot inversion in patients with varus deformities. This is suitable for gait training, as it can adjust the orthosis stiffness according to the foot condition.

Improving Accelerometry-Based Measurement of Functional Use of the Upper Extremity After Stroke: Machine Learning Versus Counts Threshold Method

Background Wrist-worn accelerometry provides objective monitoring of upper-extremity functional use, such as reaching tasks, but also detects nonfunctional movements, leading to ambiguity in monitoring results. Objective Compare machine learning algorithms with standard methods (counts ratio) to improve accuracy in detecting functional activity. Methods Healthy controls and individuals with stroke performed unstructured tasks in a simulated community environment (Test duration = 26 ± 8 minutes) while accelerometry and video were synchronously recorded. Human annotators scored each frame of the video as being functional or nonfunctional activity, providing ground truth. Several machine learning algorithms were developed to separate functional from nonfunctional activity in the accelerometer data. We also calculated the counts ratio, which uses a thresholding scheme to calculate the duration of activity in the paretic limb normalized by the less-affected limb. Results The counts ratio was not significantly correlated with ground truth and had large errors (r = 0.48; P = .16; average error = 52.7%) because of high levels of nonfunctional movement in the paretic limb. Counts did not increase with increased functional movement. The best-performing intrasubject machine learning algorithm had an accuracy of 92.6% in the paretic limb of stroke patients, and the correlation with ground truth was r = 0.99 (P < .001; average error = 3.9%). The best intersubject model had an accuracy of 74.2% and a correlation of r =0.81 (P = .005; average error = 5.2%) with ground truth. Conclusions In our sample, the counts ratio did not accurately reflect functional activity. Machine learning algorithms were more accurate, and future work should focus on the development of a clinical tool.

Dynamical Analysis of Standing Balance Control on Sloped Surfaces in Individuals with Lumbar Disc Herniation

The changes of balance control mechanism caused by lumbar disc herniation (LDH) has not been well understood. This study aimed to investigate the effects of LDH on the balance control during standing on sloped surfaces. Ten patients with LDH and 10 gender- and age-matched healthy subjects were instructed to stand quietly on a sloped surface at −5°, 0° or +5°, respectively. The trajectories of the center of pressure (COP) of each individual limb and the full-body were recorded. Cross recurrence quantification analysis (CRQA) was applied to assess the coordination of COP components at the anterior-posterior and medial-lateral directions. The patients with LDH presented magnified inter-limb load asymmetry and had more deterministic components in the COP coordination of the less-affected limb and the full-body than the healthy subjects. The LDH led to decreased dynamical degree of freedom and less flexibility in bidirectional controlling the center of mass simultaneously. The effects of sensorimotor deficits due to LDH could be more obviously exhibited as standing on a declined rather than an inclined surface. This study shed light on the effects of LDH on standing balance control and may facilitate to develop novel strategies for evaluation of LDH.

Contra-Lateral Unintended Upper Arm Movement during Unimanual Tasks in Children with Cerebral Palsy.

PurposeTo characterize associated reactions (ARs) in the contralateral arm across multiple muscles during unimanual tasks and to identify factors related to ARs in children with cerebral palsy (CP).Materials and MethodsThis was a prospective, cross-sectional study of 35 children with CP. The extent of ARs of the contra-lateral, non-task hand was assessed while performing three unimanual tasks (opening and clenching the fist, a finger opposition task, and tapping fingers). The occurrence of ARs in each trial was evaluated separately for each task using a four-point scale (total scores ranged from 0 to 12). Surface electromyography (SEMG) was used to measure the firing activity of the muscles of the opposite arm during the task. The Manual Ability Classification System and Melbourne Assessment 2 (MA-2) were used to evaluate upper limb function.ResultsAR scores were higher in the more-affected limb than in the less-affected limb. SEMG data on the non-task hand showed motor overflow up to the elbow muscles in the more-affected limb. Root mean square ratios of EMG signals were significantly higher in children with ARs than in children without ARs. Multiple regression analysis showed both age and MA-2 to be significant factors related to ARs in the more-affected limb.ConclusionChildren with visible ARs showed motor overflow in the non-task limb during unimanual hand tasks. Age and upper limb function were significantly related to the extent of ARs in the more-affected limb of children with CP.

Interlimb coupling in poststroke rehabilitation: a pilot randomized controlled trial

ABSTRACTBackground: The interlimb coupling, coordination between the limbs, gets hampered in post-stroke hemiparesis. Most of the poststroke motor regimes primarily focus on the more affected limb.Objectives: To develop an interlimb coupling protocol and assess its feasibility and effect on motor recovery, gait and disability among post-stroke subjects.Design: A pilot randomized controlled, doubled blinded trialSetting: A rehabilitation instituteMethods: 50 post-stroke (> 6 months) hemiparetic subjects (Brunnstrom recovery stage ≥ 3) were randomly divided into experimental (n=26) and control (n=24) groups. The 8-week experimental intervention (3 sessions of 1 hour each, per week) comprised activities demanding coordinated, alternate, and rhythmic use of the affected as well as the less-affected limbs. The outcome measures were feasibility of activities, Fugl-Meyer assessment (FMA), Rivermead visual gait assessment (RVGA), Functional ambulation category (FAC) and modified Rankin scale (mRS).Results: The experimental protocol was found to be feasible by the participants. Post intervention, the experimental group exhibited highly significant difference for FMA (mean difference = 7.12, 95% CI = 5.71 – 8.53, p < 0.001), RVGA reduction (mean difference = - 6.32, 95% CI = 7.51 – 5.13, p < 0.001), and median FAC enhancement (p < 0.001) in comparison to the controls. However, the median mRS level of experimental group did not change significantly (p = 0.056) when compared with the controls.Conclusions: The interlimb coupling training, a feasible program may enhance recovery of the upper and lower limbs and gait in stroke. Further definitive randomized trials are warranted to validate the present findings.

Immediate effect of a wearable foot drop stimulator to prevent foot drop on the gait ability of patients with hemiplegia after stroke

ABSTRACT The purpose of this study was to compare the effects of a foot drop stimulator (FDS) and ankle-foot orthosis (AFO) on the gait ability of patients with hemiplegia after stroke. This study recruited 10 patients with hemiplegia after stroke. All patients performed gait under two conditions (AFO and FDS gait). Gait parameters were measured with the GAITRite® system to analyze the spatial and temporal parameters of the patients’ gaits. No significant differences in cadence, velocity, swing time, stance time, or step length of the affected or less-affected limbs were found between the two conditions (all, p > .05). These findings demonstrate that AFO and FDS have a similar effect on the gait ability of patients with hemiplegia after stroke.

Low-Cost Tracking Systems Allow Fine Biomechanical Evaluation of Upper-Limb Daily-Life Gestures in Healthy People and Post-Stroke Patients.

Since the release of the first Kinect in 2011, low-cost technologies for upper-limb evaluation has been employed frequently for rehabilitation purposes. However, a limited number of studies have assessed the potential of the Kinect V2 for motor evaluations. In this paper, a simple biomechanical protocol has been developed, in order to assess the performances of healthy people and patients, during daily-life reaching movements, with focus on some of the patients’ common compensatory strategies. The assessment considers shoulder range of motion, elbow range of motion, trunk compensatory strategies, and movement smoothness. Seventy-seven healthy people and twenty post-stroke patients participated to test the biomechanical assessment. The testing protocol included four different experimental conditions: (1) dominant limb and (2) non-dominant limb of 77 healthy people, and (3) the more impaired limb of 20 post-stroke hemiparetic patients, and (4) the less-impaired limb of 11 patients (subgroup of the original 20). Biomechanical performances of the four groups were compared. Results showed that the dominant and non-dominant limbs of healthy people had comparable performances (p > 0.05). On the contrary, condition (3) showed statistically significant differences between the healthy dominant/non-dominant limb and the less-affected limb in hemiparetic patients, for all parameters of assessment (p < 0.001). In some cases, the less-affected limb of the patients also showed statistical differences (p < 0.05), with respect to the healthy people. Such results suggest that Kinect V2 has the potential for being employed at home, laboratory or clinical environment, for the evaluation of patients’ motor performances.

Comparison of accelerometer-based arm, leg and trunk activity at weekdays and weekends during subacute inpatient rehabilitation after stroke

To determine whether there are differences in arm, leg and trunk activity measured by acceleration between weekdays and weekends in people undergoing rehabilitation in the subacute stage after stroke. Cross-sectional study. Twenty-eight individuals with stroke (mean age 55.4 years; severe to mild impairment) and 10 healthy controls. A set of 5 3-axial accelerometers were used on the trunk, wrists and ankles during 2 48-h sessions at weekdays and over a weekend. Day-time acceleration raw data were expressed as the signal magnitude area. Asymmetry between the affected and less-affected limb was calculated as a ratio. Participants with stroke used their both arms and legs less at weekends than on weekdays (p< 0.05, effect size 0.32-0.57). Asymmetry between the affected and less-affected arm was greater at weekends (p < 0.05, effect size 0.32). All activity measures, apart from the less-affected arm on weekdays, were lower in stroke compared with controls (p < 0.05, effect size 0.4-0.8). No statistically significant differences were detected between weekday and weekend activity for the control group. One-third of participants perceived the trunk sensor as inconvenient to wear. Increased focus needs to be applied on activities carried out during weekends at rehabilitation wards.

Motor Units Discriminated From High-density, Surface Electromyography Require Careful Scrutiny.

High-density, surface electromyography (EMG) allows concurrent recording of motor unit (MU) activity by increasing the recording area and the number of recording sites. The recorded signal comprises overlapping MU action potentials, some of which can be identified with a decomposition algorithm. However, such analyses often produce results that contradict the classical findings on motor unit discharge characteristics. PURPOSE: To evaluate the quality of the interspike intervals (ISIs) extracted from a high-density surface EMG recording by a decomposition algorithm. METHODS: Muscle activity was recorded using high-density, surface EMG (4x8 grid with a 10 mm interelectrode distance) in 10 persons with multiple sclerosis during steady, isometric dorsiflexor contractions on their less-affected limb. The target force was 10% of maximum. Custom Matlab software was used to perform a convolution kernel compensation model and a blind-source separation algorithm to discriminate individual MUs from EMG recordings. The discharge times (DT) from the discriminated MUs were used to calculate the ISIs (ISI = DTn-DTn-1). For each MU, the average ISI, average coefficient of variation for ISI (ISICV), kurtosis for the distribution of ISIs, and skewness for the distribution of ISIs was calculated. ISIs outside of the range of 25 ms - 400 ms were deemed inaccurate and removed from the data and the same analyses were repeated. Data are reported as mean [95% CI]. RESULTS: The ISIs (n = 33,980; 303 [285-321] per MU) of 113 MUs were examined. Before removing ISIs that did not meet the inclusion criteria (25 - 400 ms), the average ISI was 136 ms [123 - 151 ms], the average ISICV was 72% [50 - 95%], the average kurtosis was 53.5 [39.1 - 67.8], and the average skewness was 4.4 [3.5 - 4.3]. On average, 3.34% (range 0 - 31%) of the ISIs per MU were outside the acceptable range. After ISI removal, the average ISI was 120 ms [114 - 125 ms], the average ISICV was 28% [26 - 31%], the average kurtosis was 11.0 [8.9 - 13.2], and the average skewness was 1.95 [1.70 - 2.20]. Most removed ISIs were <25 ms. CONCLUSION: The findings quantify the extent to which MU discharge times extracted from high-density, surface EMG recordings with an automatic decomposition algorithm can be confounded by discrimination errors.

Upper limb bilateral symmetric training with robotic assistance and clinical outcomes for stroke

Purpose – The purpose of this paper is to evaluate the physiotherapeutic benefits of bilateral symmetric training (BST) for stroke survivors affected by hemiparesis. Design/methodology/approach – Other studies have investigated symmetric physiotherapy. A key difficulty in previous work is in maintaining mirror-imaged trajectories between the affected and less-affected limbs. This obstacle was overcome in this work by using a two-armed robotic exoskeleton to enforce symmetry. In total, 15 subjects, &gt; 6 months post stroke were, randomly assigned to bilateral symmetric robotic training, unilateral robotic training, and standard physical therapy. Findings – After 12 training sessions (90 minutes/session), the bilateral training group had the greatest intensity of movement training. They also had the greatest improvement in range of motion at the shoulder. The unilateral training group showed the greatest reduction in spasticity. Research limitations/implications – The rationale for symmetric physiotherapy is that it might promote connections from the undamaged brain hemisphere. The robot generated copious amounts of detailed kinematic data. Even though these data provided insights into the human to machine interface using different training modalities, it proved difficult to draw neurological conclusions. It is recommended that future research along these lines should include measures of neurophysiological change and/or changes in neurological activity. Practical implications – This research suggests that the advantage of bilateral symmetric movement over other modalities is slight, and that robotic training has comparable results with standard care. If BST is used, care is potentially needed to avoid exacerbation of spasticity. Finally, this research includes a novel quantitative approach for evaluating robotic training. Originality/value – This study is of value to therapeutic researchers interested in new physiotherapy techniques, roboticists interested in developing rehabilitation devices, or for rehabilitation game designers interested in using virtual reality.

Muscle Weakness and Perceived Disability of Upper Limbs in Persons With Late Effects of Polio

BackgroundMuscle weakness in one or both upper limbs is common in persons with previous polio, but there is very limited knowledge how it influences daily life. ObjectiveTo assess muscle weakness and self-perceived disability of the upper limbs in persons with late effects of polio and evaluate their association. DesignCross-sectional study. SettingsUniversity hospital outpatient clinic. ParticipantsTwenty-eight persons (mean age 67, SD 16 years) with late effects of polio in their upper limbs. Main Outcome MeasuresA fixed dynamometer (Biodex System 3 PRO dynamometer (Biodex Medical Systems Inc, Shirley, NY) was used to measure isometric shoulder abduction and elbow flexion, as well as isokinetic concentric elbow flexion and extension. A hand-held dynamometer (Grippit, Hägersten, Sweden) was used to measure isometric grip strength. The Disabilities of Arm, Shoulder and Hand (DASH) questionnaire was used to assess self-perceived disability of the upper limbs. The relationships between the measures were analyzed with the Spearman rank correlation coefficients (rho). ResultsThe participants were 20%-31% weaker in their more-affected upper limb compared with their less-affected limb. The DASH score was on average 33.5 (SD 18.6), indicating a mild-to-moderate disability of their upper limbs. Changing a lightbulb overhead, carrying a heavy object, and performing recreational activities that required muscle force with the arms were perceived as most difficult. The correlations (rho) between the muscle strength measurements and DASH scores ranged from −0.46 (95% confidence interval [95% CI] −0.10 to −0.71) to −0.61 (95% CI −0.31 to −0.80) for the more affected upper limb, and from −0.54 (95% CI −0.21 to −0.76) to −0.68 (95% CI −0.41 to −0.84) for the less affected upper limb (P < .05-.01). ConclusionsPersons with previous polio and muscle weakness in their upper limbs perceive difficulties to use their arms in daily life, especially when performing activities above their head and strenuous household or leisure activities. The fair-to-moderate correlations of muscle strength with self-perceived disability imply that the weakness can only partially explain the perceived disabilities of arm, shoulder and hand. Other factors are therefore important to consider in the rehabilitation of persons with late effects of polio and upper limb disability.

Effect of Contralateral Strength Training on Muscle Weakness in People With Multiple Sclerosis: Proof-of-Concept Case Series.

The contralateral strength training (CST) effect is a transfer of muscle performance to the untrained limb following training of the contralateral side. The aim of this study was to explore, in individuals with multiple sclerosis (MS) presenting marked lower limb strength asymmetry, the effectiveness of CST on management of muscle weakness of the more-affected limb following training of the less-affected limb. A single-subject research design was used. Eight individuals with MS underwent 16 to 18 high-intensity training sessions of the less-affected ankle dorsiflexor muscles. The primary outcome measure of this single-system case series was maximal strength expressed as peak moment and maximal work. Secondary outcome measures were: Six-Minute-Walk Test, Timed "Up & Go" Test, 10-Meter Timed Walk Test, and Multiple Sclerosis Quality of Life-54 questionnaire. After the 6-week intervention, the contralateral more affected (untrained) limb showed a 22% to 24% increase in maximal strength. From pretest-posttest measurements, participants also performed significantly better on the clinical and functional secondary outcome measures. At the 12-week follow-up, the strength levels of the weaker untrained limb remained significantly superior to baseline levels in the majority (5 out of 8) of the outcome parameters. Considering the design used, the absence of a control group, and the sample size, these findings should be cautiously generalized and will need confirmation in a properly planned randomized controlled trial. The present proof-of-concept study shows, for the first time, the occurrence of the CST effect on muscle performance of ankle dorsiflexor muscles in people with MS. These preliminary findings reveal new potential implications for CST as a promising rehabilitation approach to those conditions where unilateral muscle weakness does not allow or makes difficult performing conventional strength training of the weaker limb.