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.

The Emergence of Stereotyped Kinematic Synergies when Mice Reach to Grasp Following Stroke

Reaching tasks are commonly used in preclinical and clinical studies to assess the acquisition of fine motor skills and recovery of function following stroke. These tasks are often used to assess functional deficits in the absence of quantifying the quality of movement which requires kinematic analysis. To meet this need, this study uses a kinematic analysis in mice performing the Montoya staircase task at 5 and 14 days following a cortical photothrombosis-induced stroke. Following stroke, the mice had reaching impairments associated with sustained deficits including longer, unsmooth, and less individuated paw trajectories. Two weeks after stroke we also detected the emergence of abnormal elbow and shoulder angles, flexion/extensions, and stereotyped kinematic synergies. These data suggest that proximal and distal segments acting in concert is paramount during post-stroke reaching and encourage further analysis of synergies within the translational pipeline of preclinical to clinical studies.

Smoothness metrics for reaching performance after stroke. Part 1: which one to choose?

Background

Smoothness is commonly used for measuring movement quality of the upper paretic limb during reaching tasks after stroke. Many different smoothness metrics have been used in stroke research, but a ‘valid’ metric has not been identified. A systematic review and subsequent rigorous analysis of smoothness metrics used in stroke research, in terms of their mathematical definitions and response to simulated perturbations, is needed to conclude whether they are valid for measuring smoothness. Our objective was to provide a recommendation for metrics that reflect smoothness after stroke based on: (1) a systematic review of smoothness metrics for reaching used in stroke research, (2) the mathematical description of the metrics, and (3) the response of metrics to simulated changes associated with smoothness deficits in the reaching profile.

Methods

The systematic review was performed by screening electronic databases using combined keyword groups Stroke, Reaching and Smoothness. Subsequently, each metric identified was assessed with mathematical criteria regarding smoothness: (a) being dimensionless, (b) being reproducible, (c) being based on rate of change of position, and (d) not being a linear transform of other smoothness metrics. The resulting metrics were tested for their response to simulated changes in reaching using models of velocity profiles with varying reaching distances and durations, harmonic disturbances, noise, and sub-movements. Two reaching tasks were simulated; reach-to-point and reach-to-grasp. The metrics that responded as expected in all simulation analyses were considered to be valid.

Results

The systematic review identified 32 different smoothness metrics, 17 of which were excluded based on mathematical criteria, and 13 more as they did not respond as expected in all simulation analyses. Eventually, we found that, for reach-to-point and reach-to-grasp movements, only Spectral Arc Length (SPARC) was found to be a valid metric.

Conclusions

Based on this systematic review and simulation analyses, we recommend the use of SPARC as a valid smoothness metric in both reach-to-point and reach-to-grasp tasks of the upper limb after stroke. However, further research is needed to understand the time course of smoothness measured with SPARC for the upper limb early post stroke, preferably in longitudinal studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00949-6.

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.

Corticospinal Tract Microstructure Predicts Distal Arm Motor Improvements in Chronic Stroke

BACKGROUND AND PURPOSE

The corticospinal tract (CST) is a crucial brain pathway for distal arm and hand motor control. We aimed to determine whether a diffusion tensor imaging (DTI)-derived CST metric predicts distal upper extremity (UE) motor improvements in chronic stroke survivors.

METHODS

We analyzed clinical and neuroimaging data from a randomized controlled rehabilitation trial. Participants completed clinical assessments and neuroimaging at baseline and clinical assessments 4 months later, postintervention. Using univariate linear regression analysis, we determined the linear relationship between the DTI-derived CST fractional anisotropy asymmetry (FAasym) and the percentage of baseline change in log-transformed average Wolf Motor Function Test time for distal items (ΔlnWMFT-distal_%). The least absolute shrinkage and selection operator (LASSO) linear regressions with cross-validation and bootstrapping were used to determine the relative weighting of CST FAasym, other brain metrics, clinical outcomes, and demographics on distal motor improvement. Logistic regression analyses were performed to test whether the CST FAasym can predict clinically significant UE motor improvement.

RESULTS

lnWMFT-distal significantly improved at the group level. Baseline CST FAasym explained 26% of the variance in ΔlnWMFT-distal_%. A multivariate LASSO model including baseline CST FAasym, age, and UE Fugl-Meyer explained 39% of the variance in ΔlnWMFT-distal_%. Further, CST FAasym explained more variance in ΔlnWMFT-distal_% than the other significant predictors in the LASSO model.

DISCUSSION AND CONCLUSIONS

CST microstructure is a significant predictor of improvement in distal UE motor function in the context of an UE rehabilitation trial in chronic stroke survivors with mild-to-moderate motor impairment.Video Abstract available for more insight from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A350).

Associations between upper extremity functioning and kinematics in people with spinal cord injury

Introduction

More knowledge of the relationships between kinematic measures and clinical assessments is required to guide clinical decision making and future research.

Objectives

To determine which kinematic variables obtained during a drinking task were associated with clinical assessments of upper extremity functioning in people with spinal cord injury (SCI).

Methods

In total, 25 individuals with chronic cervical (n = 17) or thoracic (n = 8) complete (n = 14) or motor incomplete (n = 11) SCI (mean age 58.4, SD 13.8) were included. Kinematic data, including movement time, smoothness and joint angles was captured with a 5-camera optoelectronic system during a unimanual drinking task. Action Research Arm Test (ARAT), Sollerman Hand Function Test (SHFT) and basic hand classification of the Upper Extremity Data Set (ISCI-Hand) were used as clinical assessments. Multiple regression analysis was used to identify kinematic variables associated with clinical assessments after controlling for potential confounding factors, such as, age, severity of SCI, sensory function, and hand surgery.

Results

Movement time, smoothness and movement pattern kinematics including trunk displacement, elbow and wrist joint angles were correlated (p < 0.05) with all three clinical scales while the velocity-related kinematics and inter-joint coordination showed low correlations. Multiple regression analysis revealed that wrist angle combined with movement time or smoothness explained 82% and 77% of the total variance in ARAT and SHFT, respectively. Wrist angle alone explained 59% of the variance in ISCI-Hand. The proprioception of the hand increased the explanatory power in the models of ARAT and SHFT. Associations between kinematics and clinical assessments in the subgroup with cervical SCI were equivalent to the whole group analyses. The number of participants in the subgroup with thoracic SCI was small and only allowed limited analysis.

Conclusions

Wrist angle, movement time, movement smoothness are the most important kinematic variables associated with upper extremity clinical assessments in people with SCI. The results are most valid for individuals with cervical SCI. All three assessments are appropriate for SCI. Further research with larger representative sample of thoracic SCI needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00938-9.

Smoothness metric during reach-to-grasp after stroke: part 2. longitudinal association with motor impairment

BACKGROUND

The cause of smoothness deficits as a proxy for quality of movement post stroke is currently unclear. Previous simulation analyses showed that spectral arc length (SPARC) is a valid metric for investigating smoothness during a multi-joint goal-directed reaching task. The goal of this observational study was to investigate how SPARC values change over time, and whether SPARC is longitudinally associated with the recovery from motor impairments reflected by the Fugl-Meyer motor assessment of the upper extremity (FM-UE) in the first 6 months after stroke.

METHODS

Forty patients who suffered a first-ever unilateral ischemic stroke (22 males, aged 58.6 ± 12.5 years) with upper extremity paresis underwent kinematic and clinical measurements in weeks 1, 2, 3, 4, 5, 8, 12, and 26 post stroke. Clinical measures included amongst others FM-UE. SPARC was obtained by three-dimensional kinematic measurements using an electromagnetic motion tracking system during a reach-to-grasp movement. Kinematic assessments of 12 healthy, age-matched individuals served as reference. Longitudinal linear mixed model analyses were performed to determine SPARC change over time, compare smoothness in patients with reference values of healthy individuals, and establish the longitudinal association between SPARC and FM-UE scores.

RESULTS

SPARC showed a significant positive longitudinal association with FM-UE (B: 31.73, 95%-CI: [27.27 36.20], P < 0.001), which encompassed significant within- and between-subject effects (B: 30.85, 95%-CI: [26.28 35.41], P < 0.001 and B: 50.59, 95%-CI: [29.97 71.21], P < 0.001, respectively). Until 5 weeks post stroke, progress of time contributed significantly to the increase in SPARC and FM-UE scores (P < 0.05), whereafter they levelled off. At group level, smoothness was lower in patients who suffered a stroke compared to healthy subjects at all time points (P < 0.05).

CONCLUSIONS

The present findings show that, after stroke, recovery of smoothness in a multi-joint reaching task and recovery from motor impairments are longitudinally associated and follow a similar time course. This suggests that the reduction of smoothness deficits quantified by SPARC is a proper objective reflection of recovery from motor impairment, as reflected by FM-UE, probably driven by a common underlying process of spontaneous neurological recovery early post stroke.

Quantification of the relative arm use in patients with hemiparesis using inertial measurement units

Introduction

Accelerometry-based activity counting for measuring arm use is prone to overestimation due to non-functional movements. In this paper, we used an inertial measurement unit (IMU)-based gross movement (GM) score to quantify arm use.

Methods

In this two-part study, we first characterized the GM by comparing it to annotated video recordings of 5 hemiparetic patients and 10 control subjects performing a set of activities. In the second part, we tracked the arm use of 5 patients and 5 controls using two wrist-worn IMUs for 7 and 3 days, respectively. The IMU data was used to develop quantitative measures (total and relative arm use) and a visualization method for arm use.

Results

From the characterization study, we found that GM detects functional activities with 50–60% accuracy and eliminates non-functional activities with >90% accuracy. Continuous monitoring of arm use showed that the arm use was biased towards the dominant limb and less paretic limb for controls and patients, respectively.

Conclusions

The gross movement score has good specificity but low sensitivity in identifying functional activity. The at-home study showed that it is feasible to use two IMU-watches to monitor relative arm use and provided design considerations for improving the assessment method.

Clinical trial registry number: CTRI/2018/09/015648

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.

Effect of post-stroke spasticity on voluntary movement of the upper limb

Background

Hemiparesis following stroke is often accompanied by spasticity. Spasticity is one factor among the multiple components of the upper motor neuron syndrome that contributes to movement impairment. However, the specific contribution of spasticity is difficult to isolate and quantify. We propose a new method of quantification and evaluation of the impact of spasticity on the quality of movement following stroke.

Methods

Spasticity was assessed using the Tonic Stretch Reflex Threshold (TSRT). TSRT was analyzed in relation to stochastic models of motion to quantify the deviation of the hemiparetic upper limb motion from the normal motion patterns during a reaching task. Specifically, we assessed the impact of spasticity in the elbow flexors on reaching motion patterns using two distinct measures of the ‘distance’ between pathological and normal movement, (a) the bidirectional Kullback–Liebler divergence (BKLD) and (b) Hellinger’s distance (HD). These measures differ in their sensitivity to different confounding variables. Motor impairment was assessed clinically by the Fugl-Meyer assessment scale for the upper extremity (FMA-UE). Forty-two first-event stroke patients in the subacute phase and 13 healthy controls of similar age participated in the study. Elbow motion was analyzed in the context of repeated reach-to-grasp movements towards four differently located targets. Log-BKLD and HD along with movement time, final elbow extension angle, mean elbow velocity, peak elbow velocity, and the number of velocity peaks of the elbow motion were computed.

Results

Upper limb kinematics in patients with lower FMA-UE scores (greater impairment) showed greater deviation from normality when the distance between impaired and normal elbow motion was analyzed either with the BKLD or HD measures. The severity of spasticity, reflected by the TSRT, was related to the distance between impaired and normal elbow motion analyzed with either distance measure. Mean elbow velocity differed between targets, however HD was not sensitive to target location. This may point at effects of spasticity on motion quality that go beyond effects on velocity.

Conclusions

The two methods for analyzing pathological movement post-stroke provide new options for studying the relationship between spasticity and movement quality under different spatiotemporal constraints.

Validity and reliability of an electromyography-based upper limb assessment quantifying selective voluntary motor control in children with upper motor neuron lesions

Current clinical assessments evaluating selective voluntary motor control are measured on an ordinal scale. We combined the Selective Control of the Upper Extremity Scale (SCUES) with surface electromyography to develop a more objective and interval-scaled assessment of selective voluntary motor control. The resulting Similarity Index (SI) quantifies the similarity of muscle activation patterns. We aimed to evaluate the validity and reliability of this new assessment named SISCUES (Similarity Index of the SCUES) in children with upper motor neuron lesions. Thirty-three patients (12.2 years [8.8;14.9]) affected by upper motor neuron lesions with mild to moderate impairments and 31 typically developing children (11.6 years [8.5;13.9]) participated. We calculated reference muscle activation patterns for the SISCUES using data of 33 neurologically healthy adults (median [1st; 3rd quantile]: 32.5 [27.9; 38.3]). We calculated Spearman correlations (ρ) between the SISCUES and the SCUES and the Manual Ability Classification System (MACS) to establish concurrent validity. Discriminative validity was tested by comparing scores of patients and healthy peers with a robust ANCOVA. Intraclass correlation coefficients2,1 and minimal detectable changes indicated relative and absolute reliability. The SISCUES correlates strongly with SCUES (ρ = 0.76, p < 0.001) and moderately with the MACS (ρ = -0.58, p < 0.001). The average SISCUES can discriminate between patients and peers. The intraclass correlation coefficient2,1 was 0.90 and the minimal detectable change was 0.07 (8% of patients' median score). Concurrent validity, discriminative validity, and reliability of the SISCUES were established. Further studies are needed to evaluate whether it is responsive enough to detect changes from therapeutic interventions.

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.

Comparing a Novel Neuroanimation Experience to Conventional Therapy for High-Dose Intensive Upper-Limb Training in Subacute Stroke: The SMARTS2 Randomized Trial

BACKGROUND

Evidence from animal studies suggests that greater reductions in poststroke motor impairment can be attained with significantly higher doses and intensities of therapy focused on movement quality. These studies also indicate a dose-timing interaction, with more pronounced effects if high-intensity therapy is delivered in the acute/subacute, rather than chronic, poststroke period.

OBJECTIVE

To compare 2 approaches of delivering high-intensity, high-dose upper-limb therapy in patients with subacute stroke: a novel exploratory neuroanimation therapy (NAT) and modified conventional occupational therapy (COT).

METHODS

A total of 24 patients were randomized to NAT or COT and underwent 30 sessions of 60 minutes time-on-task in addition to standard care. The primary outcome was the Fugl-Meyer Upper Extremity motor score (FM-UE). Secondary outcomes included Action Research Arm Test (ARAT), grip strength, Stroke Impact Scale hand domain, and upper-limb kinematics. Outcomes were assessed at baseline, and days 3, 90, and 180 posttraining. Both groups were compared to a matched historical cohort (HC), which received only 30 minutes of upper-limb therapy per day.

RESULTS

There were no significant between-group differences in FM-UE change or any of the secondary outcomes at any timepoint. Both high-dose groups showed greater recovery on the ARAT (7.3 ± 2.9 points; P = .011) but not the FM-UE (1.4 ± 2.6 points; P = .564) when compared with the HC.

CONCLUSIONS

Neuroanimation may offer a new, enjoyable, efficient, and scalable way to deliver high-dose and intensive upper-limb therapy.

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.

Relationships Between Stepping-Reaction Movement Patterns and Clinical Measures of Balance, Motor Impairment, and Step Characteristics After Stroke

OBJECTIVE

Successful stepping reactions, led by either the paretic or nonparetic leg, in response to a loss of balance are critical to safe mobility poststroke. The purpose of this study was to measure sagittal plane hip, knee, ankle, and trunk kinematics during 2-step stepping reactions initiated by paretic and nonparetic legs of people who had stroke and members of a control group.

METHODS

Principal component analysis (PCA) was used to reduce the data into movement patterns explaining interlimb coordination of the stepping and stance legs. Correlations among principal components loading scores and clinical measures of balance ability (as measured on the Community Balance and Mobility scale), motor impairment (as measured on the foot and leg sections of the Chedoke-McMaster Stroke Assessment), and step characteristics (length and velocity) were used to examine the effect of stroke on stepping reaction movement patterns.

RESULTS

The first 5 principal components explained 95.9% of the movement pattern of stepping reactions and differentiated between stepping reactions initiated by paretic legs, nonparetic legs, or the legs of controls. Moderate-strong associations (ρ/r > 0.50) between specific principal component loading scores and clinical measures and step characteristics were dependent on the initiating leg. Lower levels of motor impairment, higher levels of balance ability, and faster and longer steps were associated with stepping reactions initiated by the paretic leg that comprised paretic leg flexion and nonparetic leg extension. Step initiation with the nonparetic leg showed associations between higher scores on clinical measures and movement patterns of flexion in both paretic and nonparetic legs.

CONCLUSIONS

Movement patterns of stepping reactions poststroke were influenced by the initiating leg. After stroke, specific movement patterns showed associations with clinical measures depending on the initiating leg, suggesting that these movement patterns are important to retraining of stepping reactions. Specifically, use of flexion patterning and assessment of between-leg pattern differentiation may be important aspects to consider during retraining of stepping reactions poststroke.

IMPACT

Evidence-based interventions targeting balance reactions are still in their infancy. This investigation of stepping reactions poststroke addresses a major gap in research.

Application of Image Registration to Analyze the Clavicular Rotation of Normal Upper Limb Motion in the Sagittal Plane

OBJECTIVE

To use image registration techniques to study the clavicular rotation of the shoulders in the sagittal plane.

METHODS

From 28 April 2019 to 20 May 2019, 13 healthy adults (7 males and 6 females) with no history of shoulder trauma surgery or chronic pain were recruited. Patients' ages ranged from 22 to 42 years, with a mean age of 26.5 years. Three-dimensional composite images of the sternum-clavicle-humerus were taken using CT images of upper limb movement in the sagittal plane in the 13 healthy adults. Four different postures were registered: (i) anatomical supine position; (ii) elbow joints lifted anteriorly in the supine position; (iii) posterosuperior hyperextension of the elbow joints in the prone position; and (iv) posteroinferior hyperextension of the elbow joints in the prone position. Image data from the humerus and clavicle in three of the postures were processed to calculate Euler angles for movements in the sagittal plane. SPSS 19 was used to perform statistical analyses.

RESULTS

There was no significant difference in the angles of change in the clavicle and humerus between the dominant and non-dominant sides under different movement patterns. For upper limb movements in the sagittal plane, the clavicle displayed different Euler angles in different postures. The rotation angle from the anatomical to the horizontal position was the smallest angle, with an average value of 7.1°, whereas the rotation angle from horizontal to posterosuperior hyperextension was the largest, with an average value of 37.2°. When the upper limb moved from anterior protraction to a posterosuperior extension, the intrinsic rotation angle of the clavicle reached its maximum, with an average value of 27.9°; when moved from the anatomical to the horizontal position, 9.1% of the sagittal rotation was executed by the clavicle. During rotation from the horizontal position to posterosuperior hyperextension and from the anatomical to posterior extension, the clavicle showed relatively higher weights at 29.5% and 37.0%, respectively.

CONCLUSION

Our results showed that dominance was not a consideration when studying clavicular rotation. Image registration is an effective method that can be used to study upper limb scapular movements. Through comparing and analyzing the data, two postures had relatively large changes in the rotation angle. This can help improve indicators of clavicular rotational function during physical examinations and postoperative functional evaluations.

Computerised patient-specific prediction of the recovery profile of upper limb capacity within stroke services: the next step

INTRODUCTION

Predicting upper limb capacity recovery is important to set treatment goals, select therapies and plan discharge. We introduce a prediction model of the patient-specific profile of upper limb capacity recovery up to 6 months poststroke by incorporating all serially assessed clinical information from patients.

METHODS

Model input was recovery profile of 450 patients with a first-ever ischaemic hemispheric stroke measured using the Action Research Arm Test (ARAT). Subjects received at least three assessment sessions, starting within the first week until 6 months poststroke. We developed mixed-effects models that are able to deal with one or multiple measurements per subject, measured at non-fixed time points. The prediction accuracy of the different models was established by a fivefold cross-validation procedure.

RESULTS

A model with only ARAT time course, finger extension and shoulder abduction performed as good as models with more covariates. For the final model, cross-validation prediction errors at 6 months poststroke decreased as the number of measurements per subject increased, from a median error of 8.4 points on the ARAT (Q1-Q3:1.7-28.1) when one measurement early poststroke was used, to 2.3 (Q1-Q3:1-7.2) for seven measurements. An online version of the recovery model was developed that can be linked to data acquisition environments.

CONCLUSION

Our innovative dynamic model can predict real-time, patient-specific upper limb capacity recovery profiles up to 6 months poststroke. The model can use all available serially assessed data in a flexible way, creating a prediction at any desired moment poststroke, stand-alone or linked with an electronic health record system.

A domestic robotic rehabilitation device for assessment of wrist function for outpatients

Introduction

Available robot-assisted stroke rehabilitation systems are often limited in their utilization in the home environment, due to several barriers such as high cost, absence of therapists, tedious training tasks, or encumbering interfaces. This paper presents a low-cost robotic rehabilitation and assessment device for restoring wrist function, offering wrist exercises incorporating pronation-supination and flexion-extension movements. Furthermore, the device is designed for the assessment of joint stiffness of the wrist, and range of motion in two degrees of freedom. Methods: Mechanical/electrical design of the device as well as the control system is described. A preliminary evaluation focused on the measurement of the torsional stiffness of the limb is presented. It is evaluated by reconstructing the known stiffness values of torsional springs by measuring the motor current required to displace them.

Results

The device demonstrates the ability to determine the stiffness of an object with low-cost hardware. Use case scenarios of the device for training and assessment of the wrist are presented, allowing for a range of motion of ± 75 ° and ± 65 ° , for pronation-supination and flexion-extension respectively.

Conclusion

The device shows potential to help objectively quantify the stiffness of the wrist movement, which consecutively could be used to represent and quantify the degree of impairment of patients after stroke in a more objective manner. Further clinical study is necessary to examine this.

Test-retest repeatability reveals a temporal kinematic signature for an upper limb precision grasping task in adults

Hand-eye coordination skills, such as reaching and grasping, are fundamentally important for the performance of most daily activities. Upper limb kinematics recorded by motion tracking systems provide detailed insight into the central nervous system control of movement planning and execution. For example, kinematic metrics can reveal deficits in control, and compensatory neuromotor strategies in individuals with neuropathologies. However, the clinical utility of kinematic metrics is currently limited because their psychometric properties, such as test-retest repeatability, have not been well characterized. Therefore, the purpose of this study was to examine the degree of repeatability of spatiotemporal kinematic metrics and determine which, if any, measures form a kinematic signature for a precision grasping task. Healthy adults (n = 40) were tested on two occasions separated by 5-10 days on a bead threading task consisting of reaching and precision grasping. Results showed good test-retest repeatability for reach peak velocity, reach and grasp durations, whereas poor to moderate reliability was observed for measures of spatial precision and maximum grip aperture. In addition, analysis showed that reliable estimates of kinematic metrics can be obtained using 10 trials. Overall, our results indicate that reach peak velocity and temporal metrics form a stable characteristic, or a kinematic signature, of individual performance on a standardized bead threading task. These findings suggest potential utility in applying kinematic metrics for clinical assessment of upper limb reaching tasks.

Are early measured resting-state EEG parameters predictive for upper limb motor impairment six months poststroke?

OBJECTIVES

Investigate whether resting-state EEG parameters recorded early poststroke can predict upper extremity motor impairment reflected by the Fugl-Meyer motor score (FM-UE) after six months, and whether they have prognostic value in addition to FM-UE at baseline.

METHODS

Quantitative EEG parameters delta/alpha ratio (DAR), brain symmetry index (BSI) and directional BSI (BSIdir) were derived from 62-channel resting-state EEG recordings in 39 adults within three weeks after a first-ever ischemic hemispheric stroke. FM-UE scores were acquired within three weeks (FM-UE_baseline) and at 26 weeks poststroke (FM-UE_w26). Linear regression analyses were performed using a forward selection procedure to predict FM-UE_w26.

RESULTS

BSI calculated over the theta band (BSI_theta) (β = -0.40; p = 0.013) was the strongest EEG-based predictor regarding FM-UE_w26. BSI_theta (β = -0.27; p = 0.006) remained a significant predictor when added to a regression model including FM-UE_baseline, increasing explained variance from 61.5% to 68.1%.

CONCLUSION

Higher BSI_theta values, reflecting more power asymmetry over the hemispheres, predict more upper limb motor impairment six months after stroke. Moreover, BSI_theta shows additive prognostic value regarding FM-UE_w26 next to FM-UE_baseline scores, and thereby contains unique information regarding upper extremity motor recovery.

SIGNIFICANCE

To our knowledge, we are the first to show that resting-state EEG parameters can serve as prognostic biomarkers of stroke recovery, in addition to FM-UE_baseline scores.

International consensus recommendations for outcome measurement in post-stroke arm rehabilitation trials

BACKGROUND

Existing randomized controlled trials (RCTs) of arm rehabilitation interventions after stroke use a wide range of outcome measures, limiting ability to pool data to determine efficacy. Published recommendations also lack stroke survivor, carer and clinician involvement specifically about perceived relevance and importance of outcomes and measures.

AIM

To generate international consensus recommendations for selection of outcome measures for use in future stroke RCTs in arm rehabilitation, considering outcomes important to stroke survivors, carers and clinicians. The recommendations are the Standardizing Measurement in Arm Rehabilitation Trials (SMART) Toolbox.

DESIGN

Two-round international e-Delphi Survey and consensus meeting.

SETTING

Online and University.

POPULATION

Fifty-five researchers and clinicians with expertise in stroke upper limb rehabilitation from 18 countries (e-Delphi); N.=13 researchers and clinicians, N.=2 stroke survivors, N.=1 carer (consensus meeting).

METHODS

Using systematically identified outcome measures from published RCTs, we conducted a two-round international e-Delphi Survey with researchers and clinicians to identify the most important measures for inclusion in the toolbox. Measures that achieved ≥60% consensus were categorized using the International Classification of Functioning, Disability and Health Framework (ICF); psychometric properties were ascertained from literature and research resources. At a final consensus meeting, expert stakeholders selected measures for inclusion in the toolbox.

RESULTS

e-Delphi participants recommended 28/170 measures for discussion at the final consensus meeting. Expert stakeholders (N.=16) selected the Visual Analogue Scale for pain/0-10 Numeric Pain Rating Scale, dynamometry, Action Research Arm Test, Wolf Motor Function Test, Barthel Index, Motricity Index and Fugl-Meyer Assessment (upper limb section of each), Box and Block Test, Motor Activity Log 14, Nine Hole Peg Test, Functional Independence Measure, EQ-5D, Canadian Occupational Performance Measure and Modified Rankin Scale for inclusion in the toolbox.

CONCLUSIONS

The SMART Toolbox provides a refined selection of measures that capture outcomes considered important by stakeholders for each ICF domain.

CLINICAL REHABILITATION IMPACT

The toolbox will facilitate data aggregation for efficacy analyses thereby strengthening evidence to inform clinical practice. Clinicians can also use the toolbox to guide selection of measures ensuring a patient-centered focus.

Relationships between accelerometry and general compensatory movements of the upper limb after stroke

Background

Standardized assessments are used in rehabilitation clinics after stroke to measure restoration versus compensatory movements of the upper limb. Accelerometry is an emerging tool that can bridge the gap between in- and out-of-clinic assessments of the upper limb, but is limited in that it currently does not capture the quality of a person’s movement, an important concept to assess compensation versus restoration. The purpose of this analysis was to characterize how accelerometer variables may reflect upper limb compensatory movement patterns after stroke.

Methods

This study was a secondary analysis of an existing data set from a Phase II, single-blind, randomized, parallel dose–response trial (NCT0114369). Sources of data utilized were: (1) a compensatory movement score derived from video analysis of the Action Research Arm Test (ARAT), and (2) calculated accelerometer variables quantifying time, magnitude and variability of upper limb movement from the same time point during study participation for both in-clinic and out-of-clinic recording periods.

Results

Participants had chronic upper limb paresis of mild to moderate severity. Compensatory movement scores varied across the sample, with a mean of 73.7 ± 33.6 and range from 11.5 to 188. Moderate correlations were observed between the compensatory movement score and each accelerometer variable. Accelerometer variables measured out-of-clinic had stronger relationships with compensatory movements, compared with accelerometer variables in-clinic. Variables quantifying time, magnitude, and variability of upper limb movement out-of-clinic had relationships to the compensatory movement score.

Conclusions

Accelerometry is a tool that, while measuring movement quantity, can also reflect the use of general compensatory movement patterns of the upper limb in persons with chronic stroke. Individuals who move their limbs more in daily life with respect to time and variability tend to move with less movement compensations and more typical movement patterns. Likewise, individuals who move their paretic limbs less and their non-paretic limb more in daily life tend to move with more movement compensations at all joints in the paretic limb and less typical movement patterns.

Kinematic parameters obtained with the ArmeoSpring for upper-limb assessment after stroke: a reliability and learning effect study for guiding parameter use

BACKGROUND

After stroke, kinematic measures obtained with non-robotic and robotic devices are highly recommended to precisely quantify the sensorimotor impairments of the upper-extremity and select the most relevant therapeutic strategies. Although the ArmeoSpring exoskeleton has demonstrated its effectiveness in stroke motor rehabilitation, its interest as an assessment tool has not been sufficiently documented. The aim of this study was to investigate the psychometric properties of selected kinematic parameters obtained with the ArmeoSpring in post-stroke patients.

METHODS

This study involved 30 post-stroke patients (mean age = 54.5 ± 16.4 years; time post-stroke = 14.7 ± 26.7 weeks; Upper-Extremity Fugl-Meyer Score (UE-FMS) = 40.7 ± 14.5/66) who participated in 3 assessment sessions, each consisting of 10 repetitions of the 'horizontal catch' exercise. Five kinematic parameters (task and movement time, hand path ratio, peak velocity, number of peak velocity) and a global Score were computed from raw ArmeoSpring' data. Learning effect and retention were analyzed using a 2-way repeated-measures ANOVA, and reliability was investigated using the intra-class correlation coefficient (ICC) and minimal detectable change (MDC).

RESULTS

We observed significant inter- and intra-session learning effects for most parameters except peak velocity. The measures performed in sessions 2 and 3 were significantly different from those of session 1. No additional significant difference was observed after the first 6 trials of each session and successful retention was also highlighted for all the parameters. Relative reliability was moderate to excellent for all the parameters, and MDC values expressed in percentage ranged from 42.6 to 102.8%.

CONCLUSIONS

After a familiarization session, the ArmeoSpring can be used to reliably and sensitively assess motor impairment and intervention effects on motor learning processes after a stroke. Trial registration The study was approved by the local hospital ethics committee in September 2016 and was registered under number 05-0916.

Blowing up Neural Repair for Stroke Recovery: Preclinical and Clinical Trial Considerations

The repair and recovery of the brain after stroke is a field that is emerging in its preclinical science and clinical trials. However, recent large, multicenter clinical trials have been negative, and conflicting results emerge on biological targets in preclinical studies. The coalescence of negative clinical translation and confusion in preclinical studies raises the suggestion that perhaps the field of stroke recovery faces a fate similar to stroke neuroprotection, with interesting science ultimately proving difficult to translate to the clinic. This review highlights improvements in 4 areas of the stroke neural repair field that should reorient the field toward successful clinical translation: improvements in rodent genetic models of stroke recovery, consideration of the biological target in stroke recovery, stratification in clinical trials, and the use of appropriate clinical trial end points.

SWEAT2 Study: Effectiveness of Trunk Training on Gait and Trunk Kinematics After Stroke: A Randomized Controlled Trial

OBJECTIVE

Trunk training after stroke is an effective method for improving mobility, yet underlying associations leading to the observed mobility carryover effects are unknown. The purposes of this study were to investigate the effectiveness of trunk training for gait and trunk kinematics and to find explanatory variables for the mobility carryover effects.

METHODS

This study was an assessor-masked, randomized controlled trial. Participants received either additional trunk training (n = 19) or cognitive training (n = 20) after subacute stroke. Outcome measures were the Tinetti Performance-Oriented Mobility Assessment (POMA), the Trunk Impairment Scale, spatiotemporal gait parameters, center-of-mass excursions, and trunk and lower limb kinematics during walking. Multivariate analysis with post hoc analysis was performed to observe treatment effects. Correlation and an exploratory regression analysis were used to examine associations with the mobility carryover effects.

RESULTS

Significant improvements after trunk training, compared with the findings for the control group, were found for the Trunk Impairment Scale, Tinetti POMA, walking speed, step length, step width, horizontal/vertical center-of-mass excursions, and trunk kinematics. No significant differences were observed in lower limb kinematics. Anteroposterior excursions of the trunk were associated with 30% of the variability in the mobility carryover effects.

CONCLUSIONS

Carryover effects of trunk control were present during ambulation. Decreased anteroposterior movements of the thorax were the main variable explaining higher scores on the Tinetti POMA Gait subscale. However, the implementation and generalizability of this treatment approach in a clinical setting are laborious and limited, necessitating further research.

IMPACT

Trunk training is an effective strategy for improving mobility after stroke. Regaining trunk control should be considered an important treatment goal early after stroke to adequately prepare patients for walking.

Upper limb kinematics during the first year after stroke: the stroke arm longitudinal study at the University of Gothenburg (SALGOT)

Background

Reduction of compensation and improved movement quality indicate recovery after stroke. Since clinical measures alone are often inadequate to distinguish between behavioral recovery and compensation, kinematic analysis of functional tasks has been recommended.

Objective

To quantify longitudinal changes and residual deficits in movement performance and quality during the first year after stroke using kinematic analysis of drinking task.

Methods

A total of 56 participants with first ever stroke causing upper extremity impairment were extracted from a non-selected stroke unit cohort (Stroke Arm Longitudinal Study at the University of Gothenburg-SALGOT). Participants needed to able to perform the drinking task with the more-affected arm at least on 2 occasions out of 6 (3 days, 10 days, 4 weeks, and 3, 6, and 12 months) during the first year to be included. A cohort of 60 healthy individuals was used as reference. Longitudinal changes were analyzed using linear mixed models.

Results

Movement time, number of movement units, peak angular velocity of the elbow, peak hand velocity, and trunk displacement improved significantly over the first 3 months with a peak at 6 months. Movement time and peak hand velocity reached levels comparable to healthy at 3 months, but number of movement units, peak elbow angular velocity, trunk displacement, and arm abduction remained different from healthy over the first year after stroke.

Conclusions

Even when the recovery patterns of kinematics follow the known nonlinear pattern, not all kinematic measures reach the levels in par with healthy controls at one year post stroke. Since the number of movement units, peak angular velocity, trunk displacement, and arm abduction remained impaired over the first year, they might be the most suited measures to distinguish behavioral recovery from compensation strategies.

Trial registration

ClinicalTrials: NCT01115348. 4 May 2010. Retrospectively registered.

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.

A data-driven framework for selecting and validating digital health metrics: use-case in neurological sensorimotor impairments

Digital health metrics promise to advance the understanding of impaired body functions, for example in neurological disorders. However, their clinical integration is challenged by an insufficient validation of the many existing and often abstract metrics. Here, we propose a data-driven framework to select and validate a clinically relevant core set of digital health metrics extracted from a technology-aided assessment. As an exemplary use-case, the framework is applied to the Virtual Peg Insertion Test (VPIT), a technology-aided assessment of upper limb sensorimotor impairments. The framework builds on a use-case-specific pathophysiological motivation of metrics, models demographic confounds, and evaluates the most important clinimetric properties (discriminant validity, structural validity, reliability, measurement error, learning effects). Applied to 77 metrics of the VPIT collected from 120 neurologically intact and 89 affected individuals, the framework allowed selecting 10 clinically relevant core metrics. These assessed the severity of multiple sensorimotor impairments in a valid, reliable, and informative manner. These metrics provided added clinical value by detecting impairments in neurological subjects that did not show any deficits according to conventional scales, and by covering sensorimotor impairments of the arm and hand with a single assessment. The proposed framework provides a transparent, step-by-step selection procedure based on clinically relevant evidence. This creates an interesting alternative to established selection algorithms that optimize mathematical loss functions and are not always intuitive to retrace. This could help addressing the insufficient clinical integration of digital health metrics. For the VPIT, it allowed establishing validated core metrics, paving the way for their integration into neurorehabilitation trials.

Comparison of upper limb kinematics in two activities of daily living with different handling requirements

INTRODUCTION

Recently, kinematic analysis of the drinking task (DRINK) has been recommended to assess the quality of upper limb (UL) movement after stroke, but the accomplishment of this task may become difficult for poststroke patients with hand impairment. Therefore, it is necessary to study ADLs that involve a simpler interaction with a daily life target, such as the turning on a light task (LIGHT). As the knowledge of movement performed by healthy adults becomes essential to assess the quality of movement of poststroke patients, the main goal of this article was to compare the kinematic strategies used by healthy adults in LIGHT with those that are used in DRINK.

METHODS

63 adults, aged 30 to 69 years old, drank water and turned on a light, using both ULs separately, while seated. The movements of both tasks were captured by a 3D motion capture system. End-point and joint kinematics of reaching and returning phases were analysed. A multifactorial analysis of variance with repeated measures was applied to the kinematic metrics, using age, sex, body mass index and dominance as main factors.

RESULTS

Mean and peak velocities, index of curvature, shoulder flexion and elbow extension were lower in LIGHT, which suggests that the real hand trajectory was smaller in this task. In LIGHT, reaching was less smooth and returning was smoother than DRINK. The instant of peak velocity was similar in both tasks. There was a minimal anterior trunk displacement in LIGHT, and a greater anterior trunk displacement in DRINK. Age and sex were the main factors which exerted effect on some of the kinematics, especially in LIGHT.

CONCLUSION

The different target formats and hand contact in DRINK and LIGHT seem to be responsible for differences in velocity profile, efficiency, smoothness, joint angles and trunk displacement. Results suggest that the real hand trajectory was smaller in LIGHT and that interaction with the switch seems to be less demanding than with the glass. Accordingly, LIGHT could be a good option for the assessment of poststroke patients without grasping ability. Age and sex seem to be the main factors to be considered in future studies for a better match between healthy and poststroke adults.

Responsiveness of kinematic and clinical measures of upper-limb motor function after stroke: A systematic review and meta-analysis

BACKGROUND

Kinematic analysis and clinical outcome measures with established responsiveness contribute to the quantified assessment of upper-limb function post-stroke, the selection of interventions and the differentiation of motor recovery patterns.

OBJECTIVE

This systematic review and meta-analysis aimed to report trends in use and compare the responsiveness of kinematic and clinical measures in studies measuring the effectiveness of constraint-induced movement, trunk restraint and bilateral arm therapies for upper-limb function after stroke.

METHODS

In this systematic review, randomised controlled trials implementing kinematic analysis and clinical outcome measures to evaluate the effects of therapies in post-stroke adults were eligible. We searched 8 electronic databases (MEDLINE, EMBASE, Web of Science, Scopus, CINAHL, CENTRAL, OTseeker and Pedro). Risk of bias was assessed according to the Cochrane Risk of Bias domains. A meta-analysis was conducted for repeated design measures of pre- and post-test data providing estimated standardised mean differences (SMDs).

RESULTS

We included reports of 12 studies (191 participants) reporting kinematic smoothness, movement duration and efficiency, trunk and shoulder range of motion, control strategy and velocity variables in conjunction with assessment by Motor Activity Log, Fugl-Meyer Assessment and Wolf Motor Function Test. Responsiveness was higher (i.e., non-overlap of 95% confidence intervals [CIs]) for Motor Activity Log score (SMD for amount of use 1.0, 95% CI 0.75-1.25, P<0.001; SMD for quality of movement 0.96, 95% CI 0.72-1.20, P<0.001) than movement efficiency, trunk and shoulder range of motion, control strategy and peak velocity.

CONCLUSION

These results are consistent with current literature supporting the use of combined kinematic and clinical measures for comprehensive and accurate evaluation of upper-limb function post-stroke. Future research should include other design trials and rehabilitation types to confirm these findings, focusing on subgroup analysis of type of rehabilitation intervention and functional levels.

Predicting Upper Limb Motor Impairment Recovery after Stroke: A Mixture Model

OBJECTIVE

Spontaneous recovery is an important determinant of upper extremity recovery after stroke and has been described by the 70% proportional recovery rule for the Fugl-Meyer motor upper extremity (FM-UE) scale. However, this rule is criticized for overestimating the predictability of FM-UE recovery. Our objectives were to develop a longitudinal mixture model of FM-UE recovery, identify FM-UE recovery subgroups, and internally validate the model predictions.

METHODS

We developed an exponential recovery function with the following parameters: subgroup assignment probability, proportional recovery coefficient r k , time constant in weeks τ k , and distribution of the initial FM-UE scores. We fitted the model to FM-UE measurements of 412 first-ever ischemic stroke patients and cross-validated endpoint predictions and FM-UE recovery cluster assignment.

RESULTS

The model distinguished 5 subgroups with different recovery parameters ( r1 = 0.09, τ1 = 5.3, r2 = 0.46, τ2 = 10.1, r3 = 0.86, τ3 = 9.8, r4 = 0.89, τ4 = 2.7, r5 = 0.93, τ5 = 1.2). Endpoint FM-UE was predicted with a median absolute error of 4.8 (interquartile range [IQR] = 1.3-12.8) at 1 week poststroke and 4.2 (IQR = 1.3-9.8) at 2 weeks. Overall accuracy of assignment to the poor (subgroup 1), moderate (subgroups 2 and 3), and good (subgroups 4 and 5) FM-UE recovery clusters was 0.79 (95% equal-tailed interval [ETI] = 0.78-0.80) at 1 week poststroke and 0.81 (95% ETI = 0.80-0.82) at 2 weeks.

INTERPRETATION

FM-UE recovery reflects different subgroups, each with its own recovery profile. Cross-validation indicates that FM-UE endpoints and FM-UE recovery clusters can be well predicted. Results will contribute to the understanding of upper limb recovery patterns in the first 6 months after stroke. ANN NEUROL 2020;87:383-393 Ann Neurol 2020;87:383-393.

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

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