Upper Limb Kinematics in Stroke and Healthy Controls Using Target-to-Target Task in Virtual Reality

Priming constraint-induced movement therapy with intermittent theta burst stimulation to enhance upper extremity recovery in patients with stroke: protocol for a randomized controlled study

BACKGROUND

The treatments based on motor control and motor learning principles have gained popularity in the last 20 years, as well as non-invasive brain stimulations that enhance neuroplastic changes after stroke. However, the effect of intermittent theta burst stimulation (iTBS) in addition to evidence-based, intensive neurorehabilitation approaches such as modified constraint-induced movement therapy (mCIMT) is yet to be investigated.

AIM

We aim to establish a protocol for a randomized controlled study investigating the efficiency of mCIMT primed with iTBS after stroke.

METHODS

In this randomized controlled, single-blind study, patients with stroke (N = 17) will be divided into 3 groups: (a) mCIMT + real iTBS, (b) mCIMT + sham iTBS, and (c) mCIMT alone. 600-pulse iTBS will be delivered to the primary motor cortex on the ipsilesional hemisphere, and then, patients will receive mCIMT for 1 h/session, 3 sessions/week for 5 weeks. Upper extremity recovery will be assessed with Fugl-Meyer Test-Upper Extremity and Wolf Motor Function Test. Electrophysiological assessments, such as Motor-Evoked Potentials, Resting Motor Threshold, Short-Intracortical Inhibition, and Intracortical Facilitation, will also be included.

CONCLUSIONS

In this study, a protocol of an ongoing intervention study investigating the effectiveness of iTBS on ipsilesional M1 prior to the mCIMT in patients with stroke is proposed. This will be the first study to research priming mCIMT with iTBS and it may have the potential to reveal the true effect of the iTBS when it is added to the high-quality neurorehabilitation approaches.

TRIAL REGISTRATION

Trial registration number: NCT05308667.

Extended reality to assess post-stroke manual dexterity: contrasts between the classic box and block test, immersive virtual reality with controllers, with hand-tracking, and mixed-reality tests

BACKGROUND

Recent technological advancements present promising opportunities to enhance the frequency and objectivity of functional assessments, aligning with recent stroke rehabilitation guidelines. Within this framework, we designed and adapted different manual dexterity tests in extended reality (XR), using immersive virtual reality (VR) with controllers (BBT-VR-C), immersive VR with hand-tracking (BBT-VR-HT), and mixed-reality (MD-MR).

OBJECTIVE

This study primarily aimed to assess and compare the validity of the BBT-VR-C, BBT-VR-HT and MD-MR to assess post-stroke manual dexterity. Secondary objectives were to evaluate reliability, usability and to define arm kinematics measures.

METHODS

A sample of 21 healthy control participants (HCP) and 21 stroke individuals with hemiparesis (IHP) completed three trials of the traditional BBT, the BBT-VR-C, BBT-VR-HT and MD-MR. Content validity of the different tests were evaluated by asking five healthcare professionals to rate the difficulty of performing each test in comparison to the traditional BBT. Convergent validity was evaluated through correlations between the scores of the traditional BBT and the XR tests. Test-retest reliability was assessed through correlations between the second and third trial and usability was assessed using the System Usability Scale (SUS). Lastly, upper limb movement smoothness (SPARC) was compared between IHP and HCP for both BBT-VR test versions.

RESULTS

For content validity, healthcare professionals rated the BBT-VR-HT (0[0-1]) and BBT-MR (0[0-1]) as equally difficult to the traditional BBT, whereas they rated BBT-VR-C as more difficult than the traditional BBT (1[0-2]). For IHP convergent validity, the Pearson tests demonstrated larger correlations between the scores of BBT and BBT-VR-HT (r = 0.94;p < 0.001), and BBT and MD-MR (r = 0.95;p < 0.001) than BBT and BBT-VR-C (r = 0.65;p = 0.001). BBT-VR-HT and MD-MR usability were both rated as excellent, with median SUS scores of 83[57.5-91.3] and 83[53.8-92.5] respectively. Excellent reliability was found for the BBT-VR-C (ICC = 0.96;p < 0.001), BBT-VR-HT (ICC = 0.96;p < 0.001) and BBT-MR (ICC = 0.99;p < 0.001). The usability of the BBT-VR-C was rated as good with a median SUS of 70[43.8-83.8]. Upper limb movements of HCP were significantly smoother than for IHP when completing either the BBT-VR-C (t = 2.05;p = 0.043) and the BBT-VR-HT (t = 5.21;p < 0.001).

CONCLUSION

The different XR manual tests are valid, short-term reliable and usable tools to assess post-stroke manual dexterity.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT04694833 ; Unique identifier: NCT04694833, Date of registration: 11/24/2020.

Feedback Type May Change the EMG Pattern and Kinematics During Robot Supported Upper Limb Reaching Task

Haptic interfaces and virtual reality (VR) technology have been increasingly introduced in rehabilitation, facilitating the provision of various feedback and task conditions. However, correspondence between the feedback/task conditions and movement strategy during reaching tasks remains a question. To investigate movement strategy, we assessed velocity parameters and peak latency of electromyography. Ten neuromuscularly intact volunteers participated in the measurement using haptic interface and VR. Concurrent visual feedback and various terminal feedback (e.g., visual, haptic, visual and haptic) were given. Additionally, the object size for the reaching task was changed. The results demonstrated terminal haptic feedback had a significant impact on kinematic parameters; showed [Formula: see text] s ([Formula: see text]) shorter movement time and [Formula: see text] m/s ([Formula: see text]) higher mean velocity compared to no terminal feedback. Also, smaller peak latency was observed in different muscle regions based on the object size.

Effectiveness of an Intensive, Functional, and Gamified Rehabilitation Program on Upper Limb Function in People With Stroke (EnteRtain): A Multicenter Randomized Clinical Trial

BACKGROUND1

Despite a growing interest in gaming rehabilitation for upper limb (UL) recovery post-stroke, studies investigating the effects of game-based rehabilitation incorporating functional games are lacking.

OBJECTIVE

To investigate the efficacy of an intensive, functional, gamified rehabilitation program compared to task-based training on UL motor function in acute/sub-acute stroke survivors.

METHODS

This randomized, multicenter, single-blind, clinical trial comprises 120 participants with unilateral stroke who were randomized to receive either gamified training (n = 64) using the ArmAble™ [experimental group (EG)] or task-based training (n = 56) in conjunction with conventional therapy for 2 hours per day, 6 days per week for 2 weeks, followed by UL rehabilitation for another 4 weeks at home. Primary outcomes evaluated by a blinded assessor included the Fugl-Meyer Assessment-Upper Extremity (FM-UE), and Action Research Arm Test (ARAT). Data were analyzed using a linear mixed-effect regression model.

RESULTS

The mean (standard deviation) age of the participants was 54.4 ± 11.7 years (78.1% men) in the EG and 57.7 ± 10.9 years (73.2% men) in the comparator group (CG). The median (interquartile range) time since stroke was 30.0 (54.0) days in the EG and 22.5 (45.0) days in the CG. Following the 2-week intervention, a statistically significant improvement was observed in the EG for the FM-UE [between-group mean differences (95% confidence interval): -3.9 (-6.5, -1.3); P = .003]; but not for the ARAT [-2.9 (-5.8, 0.0); P = .051]. Gains at 6 weeks were significantly greater in the EG for both FM-UE [-3.9 (-6.5, -1.3); P = .003]; and ARAT [-3.0 (-5.9, -0.0); P = .046].

CONCLUSION

Gamified rehabilitation using the ArmAble™ device has shown immediate and short-term improvement in UL function after acute/sub-acute stroke.

CLINICAL TRIALS REGISTRY NUMBER

CTRI/2020/09/027651.

Immersive Virtual Reality to Assess Arm Kinematics among Older Adults with and without Major Neurocognitive Disorder - An Exploratory Cross-Sectional Study

Despite the recommendation of improving assessment objectivity and frequency, the use of immersive virtual reality to measure and quantify movement quality remains underexplored. In this study, we aimed to evaluate the reliability, validity and usability of an immersive virtual reality application, KinematicsVR, to assess upper limb kinematics among older adults with and without major neurocognitive disorder. The KinematicsVR involves the drawing of three-dimensional straight lines, circles and squares using a controller in a virtual environment. Twenty-eight older adults with or without major neurocognitive disorder were recruited. Reliability was evaluated through correlations on test-retest and validity through correlations between KinematicsVR variables and other functional tests (TEMPA, BBT-VR and Finger-Nose Test). The usability of the KinematicsVR was assessed with the System Usability Scale questionnaire. Kinematic indexes were compared between eight adults with major neurocognitive disorder and eight matched controls. Results indicated that most variables provided by the KinematicsVR had excellent reliability for tasks involving the drawing of straight lines and circles, but moderate reliability for tasks involving the drawing of squares. Secondary analyses showed that the usability of the application was excellent but few significant and strong correlations were observed between variables of the KinematicsVR and the scores of the TEMPA scale, Finger-Nose Test and BBT-VR. Adults with major neurocognitive disorder, when compared to other older adults, made larger and less linear hand movements. These findings provide perspectives for the use of immersive virtual reality to improve assessment frequency and objectivity through the autonomous measure of upper limb kinematics in older adults.

A guide to inter-joint coordination characterization for discrete movements: a comparative study

Characterizing human movement is essential for understanding movement disorders, evaluating progress in rehabilitation, or even analyzing how a person adapts to the use of assistive devices. Thanks to the improvement of motion capture technology, recording human movement has become increasingly accessible and easier to conduct. Over the last few years, multiple methods have been proposed for characterizing inter-joint coordination. Despite this, there is no real consensus regarding how these different inter-joint coordination metrics should be applied when analyzing the coordination of discrete movement from kinematic data. In this work, we consider 12 coordination metrics identified from the literature and apply them to a simulated dataset based on reaching movements using two degrees of freedom. Each metric is evaluated according to eight criteria based on current understanding of human motor control physiology, i.e, each metric is graded on how well it fulfills each of these criteria. This comparative analysis highlights that no single inter-joint coordination metric can be considered as ideal. Depending on the movement characteristics that one seeks to understand, one or several metrics among those reviewed here may be pertinent in data analysis. We propose four main factors when choosing a metric (or a group of metrics): the importance of temporal vs. spatial coordination, the need for result explainability, the size of the dataset, and the computational resources. As a result, this study shows that extracting the relevant characteristics of inter-joint coordination is a scientific challenge and requires a methodical choice. As this preliminary study is conducted on a limited dataset, a more comprehensive analysis, introducing more variability, could be complementary to these results.

Preliminary Rasch analysis of the multidimensional assessment of interoceptive awareness in adults with stroke

PURPOSE

The Multidimensional Assessment of Interoceptive Awareness (MAIA) measures interoceptive body awareness, which includes aspects such as attention regulation, self-regulation, and body listening. Our purpose was to perform a preliminary validation of the MAIA in adults with stroke using Rasch Measurement Theory.

METHODS

The original MAIA has 32 items that measure interoceptive sensibility, which is an aspect of body awareness. We performed a preliminary analysis with Rasch Measurement Theory to evaluate the unidimensionality and structural validity of the scale. We investigated overall fit to assess unidimensionality, person and item fit, person separation reliability, targeting, local item dependence, and principal components analysis of residuals.

RESULTS

Forty-one adults with chronic stroke (average 3.8 years post-stroke, 13 women, average age 57±13 years) participated in the study. Overall fit (χ 2 = 62.26, p = 0.26) and item fit were obtained after deleting 3 items and rescoring 26 items. One participant did not fit the model (2.44%). There were no floor (0.00%) or ceiling effects (0.00%). Local item dependence was found in 42 pairs. The person separation reliability was 0.91, and the person mean location was 0.06±1.12 logits.

CONCLUSIONS

The preliminary structural validity of the MAIA demonstrated good targeting and reliability, as well as unidimensionality, and good item and person fit in adults with chronic stroke. A study with a larger sample size is needed to validate our findings.

Bilateral Transfer of Performance between Real and Non-Immersive Virtual Environments in Post-Stroke Individuals: A Cross-Sectional Study

(1) Background: Post-stroke presents motor function deficits, and one interesting possibility for practicing skills is the concept of bilateral transfer. Additionally, there is evidence that the use of virtual reality is beneficial in improving upper limb function. We aimed to evaluate the transfer of motor performance of post-stroke and control groups in two different environments (real and virtual), as well as bilateral transfer, by changing the practice between paretic and non-paretic upper limbs. (2) Methods: We used a coincident timing task with a virtual (Kinect) or a real device (touch screen) in post-stroke and control groups; both groups practiced with bilateral transference. (3) Results: Were included 136 participants, 82 post-stroke and 54 controls. The control group presented better performance during most parts of the protocol; however, it was more evident when compared with the post-stroke paretic upper limb. We found bilateral transference mainly in Practice 2, with the paretic upper limb using the real interface method (touch screen), but only after Practice 1 with the virtual interface (Kinect), using the non-paretic upper limb. (4) Conclusions: The task with the greatest motor and cognitive demand (virtual-Kinect) provided transfer into the real interface, and bilateral transfer was observed in individuals post-stroke. However, this is more strongly observed when the virtual task was performed using the non-paretic upper limb first.

Limb loading enhances skill transfer between augmented and physical reality tasks during limb loss rehabilitation

BACKGROUND

Virtual and augmented reality (AR) have become popular modalities for training myoelectric prosthesis control with upper-limb amputees. While some systems have shown moderate success, it is unclear how well the complex motor skills learned in an AR simulation transfer to completing the same tasks in physical reality. Limb loading is a possible dimension of motor skill execution that is absent in current AR solutions that may help to increase skill transfer between the virtual and physical domains.

METHODS

We implemented an immersive AR environment where individuals could operate a myoelectric virtual prosthesis to accomplish a variety of object relocation manipulations. Intact limb participants were separated into three groups, the load control (CG_LD; [Formula: see text]), the AR control (CG_AR; [Formula: see text]), and the experimental group (EG; [Formula: see text]). Both the CG_AR and EG completed a 5-session prosthesis training protocol in AR while the CG_LD performed simple muscle training. The EG attempted manipulations in AR while undergoing limb loading. The CG_AR attempted the same manipulations without loading. All participants performed the same manipulations in physical reality while operating a real prosthesis pre- and post-training. The main outcome measure was the change in the number of manipulations completed during the physical reality assessments (i.e. completion rate). Secondary outcomes included movement kinematics and visuomotor behavior.

RESULTS

The EG experienced a greater increase in completion rate post-training than both the CG_AR and CG_LD. This performance increase was accompanied by a shorter motor learning phase, the EG's performance saturating in less sessions of AR training than the CG_AR.

CONCLUSION

The results demonstrated that limb loading plays an important role in transferring complex motor skills learned in virtual spaces to their physical reality analogs. While participants who did not receive limb loading were able to receive some functional benefit from AR training, participants who received the loading experienced a greater positive change in motor performance with their performance saturating in fewer training sessions.

Clinical interpretation and cutoff scores for manual ability measured by the ABILHAND questionnaire in people with stroke

BACKGROUND

The ABILHAND questionnaire is recommended to assess perceived manual ability after stroke; however, more knowledge on interpretability is needed to improve the clinical applicability.

OBJECTIVES

To determine clinically meaningful cutoff scores for different levels of perceived manual ability, assessed by ABILHAND, corresponding to established observed and perceived upper extremity assessments post stroke.

METHODS

This cross-sectional study, part of the Stroke Arm Longitudinal Study (SALGOT) at the University of Gothenburg, included 80 participants with upper extremity impairments after stroke. The self-reported upper extremity functioning was assessed with ABILHAND and Stroke Impact Scale Hand (SIS Hand), and the observed functioning was assessed by Fugl-Meyer Assessment for Upper Extremity (FMA-UE) and Action Research Arm Test (ARAT) at 3 months after stroke. Receiver operating characteristic curve, sensitivity, and specificity analyses were used to determine the cutoffs.

RESULTS

The overall discriminating accuracy was excellent (AUC > 0.90) for most of the cutoffs and sensitivity and specificity values ranged from 0.73 to 1.0. The ABILHAND cutoff score 1.78 discriminated well between low and good functioning resulting in a 95% match with SIS Hand and 87.5% match with ARAT and FMA-UE.

CONCLUSIONS

The determined cutoff scores of the ABILHAND, validated through established upper extremity assessments, will provide a useful tool to clinicians when interpreting the logit scores and when selecting individualized treatment options. ABILHAND matched well with self-reported SIS Hand, but discrepancies found with observed scales implies that self-perceived assessments should be complemented with observed assessments.

Conducting Implementation Research in Stroke Rehabilitation: A Case Example and Considerations for Study Design

As neurorehabilitation research continues to grow, the field must ensure its scientific discoveries are implemented into routine clinical care. Without targeted efforts to increase the implementation of evidence into practice, patients may never see the benefits of interventions, assessments, and technologies developed in the confines of empirical studies. This article serves as a response to Lynch et al's 2018 Point of View piece in Neurorehabilitation and Neural Repair that underscored the urgent need for implementation studies to expedite the application of neurorehabilitation evidence in practice. To address this need, we provide the following 4 considerations investigators should contemplate when designing their own studies at the intersection of implementation and neurorehabilitation research: (a) consideration of guiding theories, models, and frameworks, (b) consideration of implementation strategies, (c) considerations of target outcomes, and (d) consideration of hybrid effectiveness-implementation designs. To conclude, we also provide a study exemplar to depict how these considerations can be integrated into the neurorehabilitation research field to narrow the evidence-to-practice gap.

The Mediating Effect of Age, Gender, and Post-Stroke Duration on the Association between Trunk and Upper Limb Recovery in Subacute Stroke Population: A Cross-Sectional Study with Mediation Analysis

BACKGROUND

The trunk acts as proximal support with which limbs execute smooth and purposeful movement. Furthermore, as upper extremity functions are an integral component of daily living activities, exploring the association between trunk and upper extremity recovery will guide therapists in developing appropriate rehabilitation goals and interventions. The objectives of this study were to (1) assess the association between trunk and upper extremity recovery in the subacute stroke population and (2) assess the effect of trunk control on upper extremity impairment and function with age, gender, and duration of stroke as mediators using mediation analysis in subacute stroke individuals.

METHODS

This cross-sectional study included 54 subacute stroke participants with a mean age of 58.37 ± 6.11 years. The trunk impairment scale (TIS) assessed the trunk's stability, mobility, and coordination. The level of upper extremity impairment was evaluated using the Fugl-Meyer Assessment scale (FMA). The quality and quantity of upper limb motor functions were measured using the Wolf motor function test (WMFT).

RESULTS

The TIS exhibited moderate positive correlations with the FMA-UE, WMFT-time scale (TS), and WMFT-functional ability scale (FAS) at p < 0.001. The mediation analysis reported a profound mediation effect of post-stroke duration on the association of trunk and upper limb recovery.

CONCLUSIONS

The study results substantiated that trunk control significantly correlates with upper limb impairment and the quality and quantity of its use in the subacute stroke population. Post-stroke duration proved to mediate the association between trunk and upper limb recovery. Therefore, the assessment and intervention of trunk and upper extremity motor control considering the post-stroke duration is vital and should be incorporated in stroke rehabilitation aiming at functional independence.

Virtual reality gaming in rehabilitation after stroke - user experiences and perceptions

PURPOSE

The present study explored participants' experiences with and perceptions of using fully immersive head-mounted virtual reality (VR) gaming as rehabilitation after stroke.

METHODS

Four men and three women (median age 64 years) with chronic stroke and varying motor impairment (mild to severe) were interviewed after 10 weeks of VR training on the commercial HTC Vive system, focusing on the upper extremities. Inductive qualitative thematic analysis was performed.

RESULTS

The analysis revealed three main themes: playing the game, benefits and effects, and personalizing the game. Playing the game encompasses both the feeling of being immersed in the game and descriptions of the gaming being motivating and fun. Benefits and effects describe the participants' expectations of potential benefits, the importance of getting feed-back, and the impact in daily life. Personalizing the game includes finding the right game and level, and the participants' need for support to achieve full use of the training.

CONCLUSIONS

Participants with chronic stroke described the fully immersive VR gaming intervention as a fun and motivating way to improve their functioning in everyday life. Qualitative studies are needed to explore how people with stroke perceive VR gaming when it is implemented in real clinical environments.Clinical implicationsVR gaming was perceived as a positive and motivating rehabilitation after stroke.Getting feedback and perceiving benefits are essential parts of VR rehabilitation.Commercial fully immersive VR-games might be an option for stroke rehabilitation when the game can be personalized and support is available.

Superior treatment efficacy of neuromodulation rehabilitation for upper limb recovery after stroke: a meta-analysis

BACKGROUND

This study aims to explore the treatment efficacy of different motor rehabilitation interventions for upper limb impairment recovery.

RESEARCH DESIGN & METHODS

Publications were searched in PubMed and Embase. 4 grouped motor rehabilitation treatments (training, technological intervention, pharmacological intervention, and neuromodulation) were compared. The change of the Fugl-Meyer Assessment Scale for Upper Extremity (FMA-UE) was applied to assess upper limb function after stroke.

RESULTS

56 studies including 5292 patients were identified. A significant difference was found among the 4 groups (P = 0.02). Neuromodulation interventions had the best treatment efficacy among the 4 types of interventions (P < 0.01). Among neuromodulation interventions, acupuncture, electric, or magnetic intervention all had therapeutic efficacy for stroke upper limb recovery, without significant subgroup difference (P = 0.34). Stroke patients with mild upper limb impairment might not benefit from motor rehabilitation (P = 0.14).

CONCLUSION

Neuromodulation interventions might have the best therapeutic efficacy among motor rehabilitation treatments for upper limb impairment after stroke. It is a potential treatment direction for upper limb recovery among stroke patients. However, since a large proportion of the original studies are low to very low-quality evidence, large-scale RCTs should be conducted in the future to validate current findings and assess treatment effects based on patient characteristics.

Effect of compressive therapy on sensorimotor function of the more affected upper extremity in chronic stroke patients: A randomized clinical trial

BACKGROUND

Common upper extremity (UE) physical impairments after stroke include paresis, abnormal muscle tone, and somatosensory affection. This study evaluated the effect of passive somatosensory stimulation using compressive therapy on sensorimotor function of the more affected UE in chronic stroke patients.

METHODS

Forty chronic stroke patients were enrolled in this study. They were randomized into 2 groups: Gr1 and Gr2. Three patients dropped out leaving us with a total of 37 patients completing the study. Gr1 received UE motor program for the more affected UE along with sham electrical stimulation while Gr2 had the same UE motor program along with passive somatosensory stimulation. The session duration in both groups was 85 min. Gr1 and Gr2 received a total of 36 sessions for 6 successive weeks. UE function in Gr1 and Gr2 was examined, before and after treatment using Box and Block test (BBT) and Perdue Pegboard test (PPBT) as measures of motor of both the more affected and less affected UE while the Nottingham sensory assessment (NSA) scale was used as a measure of sensory function of the more affected UE.

RESULTS

There were significant improvements in motor and sensory function of the more affected UE compared to the less affected UE in both groups, measured by the BBT, PPBT, and NSA scales post-treatment (P < .05). However, the comparison between both groups regarding improvement revealed no significant change (P > .05).

CONCLUSION

Upper extremity motor and passive somatosensory stimulation techniques are effective in improving sensorimotor function of the more affected UE, but none of them had the advantage over the other, in terms of improving motor and sensory function in chronic stroke patients.

Enhancing motion tracking accuracy of a low-cost 3D video sensor using a biomechanical model, sensor fusion, and deep learning

Low-cost 3D video sensors equipped with routines for extracting skeleton data facilitate the widespread use of virtual reality (VR) for rehabilitation. However, the accuracy of the extracted skeleton data is often limited. Accuracy can be improved using a motion tracker, e.g., using a recurrent neural network (RNN). Yet, training an RNN requires a considerable amount of relevant and accurate training data. Training databases can be obtained using gold-standard motion tracking sensors. This limits the use of the RNN trackers in environments and tasks that lack accessibility to gold-standard sensors. Digital goniometers are typically cheaper, more portable, and simpler to use than gold-standard motion tracking sensors. The current work suggests a method for generating accurate skeleton data suitable for training an RNN motion tracker based on the offline fusion of a Kinect 3D video sensor and an electronic goniometer. The fusion applies nonlinear constraint optimization, where the constraints are based on an advanced shoulder-centered kinematic model of the arm. The model builds on the representation of the arm as a triangle (the arm triangle). The shoulder-centered representation of the arm triangle motion simplifies constraint representation and consequently the optimization problem. To test the performance of the offline fusion and the RNN trained using the optimized data, arm motion of eight participants was recorded using a Kinect sensor, an electronic goniometer, and, for comparison, a passive-marker-based motion tracker. The data generated by fusing the Kinect and goniometer recordings were used for training two long short-term memory (LSTM) RNNs. The input to one RNN included both the Kinect and the goniometer data, and the input to the second RNN included only Kinect data. The performance of the networks was compared to the performance of a tracker based on a Kalman filter and to the raw Kinect measurements. The accuracy of the fused data was high, and it considerably improved data accuracy. The accuracy for both trackers was high, and both were more accurate than the Kalman filter tracker and the raw Kinect measurements. The developed methods are suitable for integration with immersive VR rehabilitation systems in the clinic and the home environments.

Assessment of Neurological Impairment and Recovery Using Statistical Models of Neurologically Healthy Behavior

While many areas of medicine have benefited from the development of objective assessment tools and biomarkers, there have been comparatively few improvements in techniques used to assess brain function and dysfunction. Brain functions such as perception, cognition, and motor control are commonly measured using criteria-based, ordinal scales which can be coarse, have floor/ceiling effects, and often lack the precision to detect change. There is growing recognition that kinematic and kinetic-based measures are needed to quantify impairments following neurological injury such as stroke, in particular for clinical research and clinical trials. This paper will first consider the challenges with using criteria-based ordinal scales to quantify impairment and recovery. We then describe how kinematic-based measures can overcome many of these challenges and highlight a statistical approach to quantify kinematic measures of behavior based on performance of neurologically healthy individuals. We illustrate this approach with a visually-guided reaching task to highlight measures of impairment for individuals following stroke. Finally, there has been considerable controversy about the calculation of motor recovery following stroke. Here, we highlight how our statistical-based approach can provide an effective estimate of impairment and recovery.

Variable Impedance Control Based on Target Position and Tracking Error for Rehabilitation Robots During a Reaching Task

To obtain an anthropomorphic performance in physical human-robot interaction during a reaching task, a variable impedance control (vIC) algorithm with human-like characteristics is proposed in this article. The damping value of the proposed method is varied with the target position as well as through the tracking error. The proposed control algorithm is compared with the impedance control algorithm with constant parameters (IC) and another vIC algorithm, which is only changed with the tracking error (vIC-e). The different control algorithms are validated through the simulation study, and are experimentally implemented on a cable-driven rehabilitation robot. The results show that the proposed vIC can improve the tracking accuracy and trajectory smoothness, and reduce the interaction force at the same time.

Virtual Reality in the Neurosciences: Current Practice and Future Directions

Virtual reality has made numerous advancements in recent years and is used with increasing frequency for education, diversion, and distraction. Beginning several years ago as a device that produced an image with only a few pixels, virtual reality is now able to generate detailed, three-dimensional, and interactive images. Furthermore, these images can be used to provide quantitative data when acting as a simulator or a rehabilitation device. In this article, we aim to draw attention to these areas, as well as highlight the current settings in which virtual reality (VR) is being actively studied and implemented within the field of neurosurgery and the neurosciences. Additionally, we discuss the current limitations of the applications of virtual reality within various settings. This article includes areas in which virtual reality has been used in applications both inside and outside of the operating room, such as pain control, patient education and counseling, and rehabilitation. Virtual reality's utility in neurosurgery and the neurosciences is widely growing, and its use is quickly becoming an integral part of patient care, surgical training, operative planning, navigation, and rehabilitation.

Analysis of Upper Limbs Target-Reaching Movement and Muscle Co-Activation in Patients with First Time Stroke for Rehabilitation Progress Monitoring

In this paper, the authors analysed changes occurring during the rehabilitation processes in patients after early stroke based on analysis of their upper limbs’ target-reaching movement and muscle co-activation. Ischemic stroke often results in reduced mobility of the upper extremities and frequently is a cause for long-term disability. The ever-developing technology of 3D movement analysis and miniaturisation of equipment for testing the bioelectrical activity of muscles can help to assess the progress of rehabilitation. The aim of this study was to examine the use of analysis of target-reaching movement indicators and muscle co-activation for diagnosing the rehabilitation process in post-stroke patients. Twenty ischemic stroke patients in the early post-stroke phase (up to three months after the stroke), and twenty healthy subjects (the control group) took part in the experiments. The novel approach of the proposed research proved the usefulness of this approach in the diagnosis of the rehabilitation efficiency of rehabilitation in early post-stroke phase patients.

Predicting post-stroke motor recovery of upper extremity using clinical variables and performance assays: A prospective cohort study protocol

BACKGROUND AND PURPOSE

Measurement of movement quality is essential to distinguish motor recovery patterns and optimize rehabilitation strategies post-stroke. Recently, the Stroke Recovery and Rehabilitation Roundtable Taskforce (SRRR) recommended four kinetic and kinematic performance assays to measure upper extremity (UE) movements and distinguish behavioral restitution and compensation mechanisms early post-stroke. The purpose of this study is to develop and validate a prediction model to analyze the added prognostic value of performance assays over clinical variables assessed up to 1-month post stroke for predicting recovery of UE motor impairment, capacity and quality of movement (QoM) measured at 3 months post-stroke onset.

METHODS

In this prospective cohort study, 120 stroke survivors will be recruited within seven days post-stroke. Candidate predictors such as baseline characteristics, demographics and performance assays as per SRRR recommendations along with tonic stretch reflex threshold will be measured up to 1-month post-stroke. Upper extremity motor recovery will be evaluated in terms of motor impairment (Fugl-Meyer assessment for UE), UE capacity measured with Action Research Arm Test (ARAT) and QoM (movement smoothness in the form of peak metrics [PM]) assessed with a reach-to-grasp-to-mouth task (mimicking a drinking task) at 3 months post-stroke. Three multivariable linear regression models will be developed to predict factors responsible for the outcomes of Fugl-Meyer assessment for upper extremity (FM-UE), ARAT and movement quality. The developed models will be internally validated using a split-sample method.

DISCUSSION

This study will provide a validated prediction model inclusive of clinical and performance assays that may assist in prediction of UE motor recovery. Predicting the amount of recovery and differentiating between behavioral restitution and compensation (as reflected by the FM-UE, QoM and ARAT) would enable us in realistic goal formation and planning rehabilitation. It would also help in encouraging patients to partake in early post-stroke rehabilitation thus improving the recovery potential.

Characterization of stroke-related upper limb motor impairments across various upper limb activities by use of kinematic core set measures

Background

Upper limb kinematic assessments provide quantifiable information on qualitative movement behavior and limitations after stroke. A comprehensive characterization of spatiotemporal kinematics of stroke subjects during upper limb daily living activities is lacking. Herein, kinematic expressions were investigated with respect to different movement types and impairment levels for the entire task as well as for motion subphases.

Method

Chronic stroke subjects with upper limb movement impairments and healthy subjects performed a set of daily living activities including gesture and grasp movements. Kinematic measures of trunk displacement, shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension, forearm pronation/supination, wrist flexion/extension, movement time, hand peak velocity, number of velocity peaks (NVP), and spectral arc length (SPARC) were extracted for the whole movement as well as the subphases of reaching distally and proximally. The effects of the factors gesture versus grasp movements, and the impairment level on the kinematics of the whole task were tested. Similarities considering the metrics expressions and relations were investigated for the subphases of reaching proximally and distally between tasks and subgroups.

Results

Data of 26 stroke and 5 healthy subjects were included. Gesture and grasp movements were differently expressed across subjects. Gestures were performed with larger shoulder motions besides higher peak velocity. Grasp movements were expressed by larger trunk, forearm, and wrist motions. Trunk displacement, movement time, and NVP increased and shoulder flexion/extension decreased significantly with increased impairment level. Across tasks, phases of reaching distally were comparable in terms of trunk displacement, shoulder motions and peak velocity, while reaching proximally showed comparable expressions in trunk motions. Consistent metric relations during reaching distally were found between shoulder flexion/extension, elbow flexion/extension, peak velocity, and between movement time, NVP, and SPARC. Reaching proximally revealed reproducible correlations between forearm pronation/supination and wrist flexion/extension, movement time and NVP.

Conclusion

Spatiotemporal differences between gestures versus grasp movements and between different impairment levels were confirmed. The consistencies of metric expressions during movement subphases across tasks can be useful for linking kinematic assessment standards and daily living measures in future research and performing task and study comparisons.

Trial registration: ClinicalTrials.gov Identifier NCT03135093. Registered 26 April 2017, https://clinicaltrials.gov/ct2/show/NCT03135093.

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.

Treatment of upper limb spasticity with inhibitory repetitive transcranial magnetic stimulation: A randomized placebo-controlled trial

BACKGROUND

Upper limb dysfunction is a frequent complication after stroke impairing outcome. Inhibitory repetitive transcranial magnetic stimulation (rTMS) applied over the contralesional hemisphere is supposed to enhance the positive effects of conventional rehabilitative treatment.

OBJECTIVE

This double-blind randomized placebo-controlled trial investigated whether inhibitory rTMS as add-on to standard therapy improves upper limb spasticity.

METHODS

Twenty-eight patients (aged 44 to 80 years) with unilateral stroke in the middle cerebral artery territory were analyzed. Participants were randomly assigned to inhibitory, low-frequency (LF-) rTMS (n = 14) or sham-rTMS (n = 14). The primary outcome measure was the spasticity grade, which was assessed with the Modified Ashworth Scale (MAS). In addition, the Fugl-Meyer-Assessment (FMA) for the upper extremity (UE) and a resting-state fMRI were performed to measure motor functions and the sensorimotor network, respectively.

RESULTS

The MAS score was reduced in the LF-rTMS group only, whereas the FMA score improved in both groups over time. Regarding the fMRI data, both groups activated typical regions of the sensorimotor network. In the LF-rTMS group, however, connectivity to the left angular gyrus increased after treatment.

CONCLUSION

Changes in functional connectivity in patients receiving inhibitory rTMS over the contralesional motor cortex suggest that processes of neuronal plasticity are stimulated.

Effects of game-based rehabilitation on upper limb function in adults within the first six months following stroke: protocol for a systematic review and meta-analysis

OBJECTIVE

To evaluate and summarize the level of evidence for the immediate, short-term, and long-term effects of game-based rehabilitation on upper limb function in adults within the first six months following stroke.

INTRODUCTION

A game-based intervention is a valuable therapeutic tool for incorporating principles of motor learning and neuroplasticity in the rehabilitation of upper limb function post-stroke. Most of the existing reviews on game-based rehabilitation are focused on the chronic phase of stroke. However, as maximum upper limb motor recovery occurs in the first six months after stroke, further exploration of the effects of game-based rehabilitation in this phase is necessary.

INCLUSION CRITERIA

We will include randomized clinical trials assessing the immediate, short-term, and long-term effects of game-based rehabilitation on upper limb function in adults within the first six months following stroke.

METHODS

The systematic review will follow the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) checklist and JBI methodology for systematic reviews of effectiveness. A database-specific search strategy will be used in CINAHL, PubMed, Scopus, Web of Science, ProQuest, PEDro, OT Seeker, and Ovid MEDLINE to identify studies in the English language with no date limit. Two reviewers will independently screen, extract data from, and assess risk of bias in the eligible studies. Meta-analysis and publication bias evaluation will be done when adequate data are available. If a meta-analysis is precluded, then a narrative synthesis will be done. The Grading of Recommendations Assessment Development and Evaluation (GRADE) criteria will be used to assess the certainty of evidence for the outcome measures of interest.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020190100.

Occupational therapists' evaluation of the perceived usability and utility of wearable soft robotic exoskeleton gloves for hand function rehabilitation following a stroke

PURPOSE

To evaluate the perceived usability and utility of using a soft robotic glove to rehabilitate hand function following a stroke.

METHODS

A convergent parallel mixed-methods design was used to consult a convenience sample of 14 experienced occupational therapists (OTs) practicing within a specialised stroke rehabilitation program. All OTs participated in one 60-to-90-minute individual consultation during which the attributes of a recently-developed soft robotic glove (ExoGlove) were presented before they could test it on themselves. After this consultation, OTs completed the System Usability Scale (SUS) questionnaire and answered open-ended questions focussing on the usability and utility of soft robotic gloves framed according to the Unified Theory of Acceptance and Use of Technology (UTAUT).

RESULTS

The OTs perceived the glove's usability as being moderate-to-good on the SUS (median score= 63.75 on a scale of 100). Thematic analysis revealed the importance of specifically considering elements such as ease of use (e.g. simplicity and speed), cost, movement precision, durability, and safety, when developing soft robotic gloves such as the ExoGlove.

CONCLUSIONS

Engagement in a continuous improvement process is essential to maximise the perceived usability and utility of soft robotic gloves, particularly of the ExoGlove, through their final development phase before pilot testing their effects and effectiveness for post-stroke hand rehabilitation.Implications for rehabilitationAll occupational therapists anticipate that a soft robotic glove such as the ExoGlove will allow them to increase treatment intensity and best aligns with principles of neuroplasticity.The clinical judgement and guidance of OTs, developed through practice, experience, and knowledge, remain essential to safely and efficiently exercise with a soft robotic glove.Achieving a balance between effort and performance expectancies is essential in developing and improving the functionality of soft robotic gloves, as with each additional functionality comes new challenges that impact its successful transition to a clinical setting.

Effectiveness of an intensive, functional, gamified Rehabilitation program in improving upper limb motor function in people with stroke: A protocol of the EnteRtain randomized clinical trial

INTRODUCTION

Game-based rehabilitation is an emerging therapeutic intervention that allows intensive, repetitive, task-based training to improve upper limb (UL) function following stroke, based on the principles of neuro-plasticity and motor (re)learning. Rehabilitation using commercial gaming system will be motivating, enjoyable, challenging and affordable. Therefore, the present study aims at assessing the effectiveness of an intensive, functional, gamified rehabilitation program using the ArmAble™ device in improving UL motor function in people with stroke.

METHOD

In this single-blinded, multi-centric, randomized clinical trial, 120 adults with acute/sub-acute unilateral stroke will be randomized to receive an intensive, functional, gamified training program using the ArmAble™ or task-based training along with a conventional therapy for 2 h/day, 6 days/week for 2 weeks, followed by a home-based, functional rehabilitation program for another 4 weeks (~30 min/day, 6 days/week). Primary outcomes evaluated by a blinded assessor at the baseline, 2 weeks and 6 weeks' post-intervention will include the Fugl-Meyer assessment - upper extremity and the action research arm test. A linear mixed effect regression model or relevant non-parametric tests will be used to analyze the data for all outcomes. An intention-to-treat analysis will be used with missing data handled by multiple imputation.

DISCUSSION

Rehabilitation provided with the ArmAble™ device, if found effective, can be used from the early stages post-stroke to provide intensive, repetitive, gamified training to improve UL motor function.

TRIAL REGISTRATION NUMBER

CTRI/2020/09/027651.

Discussion on the Rehabilitation of Stroke Hemiplegia Based on Interdisciplinary Combination of Medicine and Engineering

Interdisciplinary combinations of medicine and engineering are part of the strategic plan of many universities aiming to be world-class institutions. One area in which these interactions have been prominent is rehabilitation of stroke hemiplegia. This article reviews advances in the last five years of stroke hemiplegia rehabilitation via interdisciplinary combination of medicine and engineering. Examples of these technologies include VR, RT, mHealth, BCI, tDCS, rTMS, and TCM rehabilitation. In this article, we will summarize the latest research in these areas and discuss the advantages and disadvantages of each to examine the frontiers of interdisciplinary medicine and engineering advances.

Clinical Application of Virtual Reality for Upper Limb Motor Rehabilitation in Stroke: Review of Technologies and Clinical Evidence

Neurorehabilitation for stroke is important for upper limb motor recovery. Conventional rehabilitation such as occupational therapy has been used, but novel technologies are expected to open new opportunities for better recovery. Virtual reality (VR) is a technology with a set of informatics that provides interactive environments to patients. VR can enhance neuroplasticity and recovery after a stroke by providing more intensive, repetitive, and engaging training due to several advantages, including: (1) tasks with various difficulty levels for rehabilitation, (2) augmented real-time feedback, (3) more immersive and engaging experiences, (4) more standardized rehabilitation, and (5) safe simulation of real-world activities of daily living. In this comprehensive narrative review of the application of VR in motor rehabilitation after stroke, mainly for the upper limbs, we cover: (1) the technologies used in VR rehabilitation, including sensors; (2) the clinical application of and evidence for VR in stroke rehabilitation; and (3) considerations for VR application in stroke rehabilitation. Meta-analyses for upper limb VR rehabilitation after stroke were identified by an online search of Ovid-MEDLINE, Ovid-EMBASE, the Cochrane Library, and KoreaMed. We expect that this review will provide insights into successful clinical applications or trials of VR for motor rehabilitation after stroke.

Effect of Wii-habilitation on spatiotemporal parameters and upper limb function post-burn in children

BACKGROUND

Limb burns can cause different functional disorders that greatly impact one's quality of life.

AIM

The purpose of the current study was to compare the effect of Nintendo Wii sports intervention, and traditional treatment methods on spatiotemporal parameters and upper limb function post-burn in children.

METHODS

Thirty children their age ranging from 7-12 years, with dominant side upper limb burn participated in the study.Vicon3-D motion analysis system and Jebsen hand function test were used to evaluate spatiotemporal parameters (movement duration, peak velocity, and time to peak velocity percentage in three functional tasks) and upper limb function respectively. The children were randomly divided into study and control groups. The study group was rehabilitated with Wii training in addition to traditional therapy, while the control group rehabilitated only with the traditional therapy program. For the study group, the games selected were Wii Bowling, Baseball, and Tennis. Both groups were trained for 60 min daily, three times/week for six weeks. The outcomes were measured pre and post the treatment period.

RESULTS

The whole-time duration and peak velocity improved significantly in the study group across the hand to head task (p = 0.001, p < 0.001, respectively), hand to mouth (p = 0.001), and hand to shoulder (p < 0.001, p = 0.0018, respectively) compared with the control group. The time to peak velocity percentage was enhanced significantly in the study group (p < 0.001) than the control group in all three-measured tasks. Moreover, the Jebsen hand function test improved significantly (p < 0.001) in the study group than in the control group.

CONCLUSION

Wii-habilitation could be advised as an effective tool in the rehabilitation program of children with post-burn injuries.

Technology-aided assessment of functionally relevant sensorimotor impairments in arm and hand of post-stroke individuals

BACKGROUND

Assessing arm and hand sensorimotor impairments that are functionally relevant is essential to optimize the impact of neurorehabilitation interventions. Technology-aided assessments should provide a sensitive and objective characterization of upper limb impairments, but often provide arm weight support and neglect the importance of the hand, thereby questioning their functional relevance. The Virtual Peg Insertion Test (VPIT) addresses these limitations by quantifying arm and hand movements as well as grip forces during a goal-directed manipulation task requiring active lifting of the upper limb against gravity. The aim of this work was to evaluate the ability of the VPIT metrics to characterize arm and hand sensorimotor impairments that are relevant for performing functional tasks.

METHODS

Arm and hand sensorimotor impairments were systematically characterized in 30 chronic stroke patients using conventional clinical scales and the VPIT. For the latter, ten previously established kinematic and kinetic core metrics were extracted. The validity and robustness of these metrics was investigated by analyzing their clinimetric properties (test-retest reliability, measurement error, learning effects, concurrent validity).

RESULTS

Twenty-three of the participants, the ones with mild to moderate sensorimotor impairments and without strong cognitive deficits, were able to successfully complete the VPIT protocol (duration 16.6 min). The VPIT metrics detected impairments in arm and hand in 90.0% of the participants, and were sensitive to increased muscle tone and pathological joint coupling. Most importantly, significant moderate to high correlations between conventional scales of activity limitations and the VPIT metrics were found, thereby indicating their functional relevance when grasping and transporting objects, and when performing dexterous finger manipulations. Lastly, the robustness of three out of the ten VPIT core metrics in post-stroke individuals was confirmed.

CONCLUSIONS

This work provides evidence that technology-aided assessments requiring goal-directed manipulations without arm weight support can provide an objective, robust, and clinically feasible way to assess functionally relevant sensorimotor impairments in arm and hand in chronic post-stroke individuals with mild to moderate deficits. This allows for a better identification of impairments with high functional relevance and can contribute to optimizing the functional benefits of neurorehabilitation interventions.

Relationship between self-reported and objectively measured manual ability varies during the first year post-stroke

Self-reported outcomes provide unique insights about an individual’s perceived manual ability after stroke. This study aimed at determining how the relationship between objective kinematic variables obtained from the target-to-target pointing task and self-reported manual ability varies during the first year in individuals after stroke. Sixty-six individuals from the Stroke Arm Longitudinal study at the University of Gothenburg (SALGOT) cohort were assessed using ABILHAND questionnaire and kinematic analysis at five timepoints between the 10^th day and 12^th month after stroke. Kinematic analysis was performed using a target-to-target pointing task in a virtual environment. Spearman’s correlation was used to determine the extent of correlation between ABILHAND logits and kinematic variables. The correlations varied with time within the first year after stroke. The correlations were low or very low early after stroke and became moderate to high after 6 months for objective measures of movement time and smoothness, but remained low to moderate for mean velocity and low for peak velocity. Due to this discrepancy between self-perceived and objective assessments of arm function, a combination of self-reported and objective assessments of upper limb should be used as outcome measures, especially in the acute and subacute stages after stroke.

Effects of robot therapy on upper body kinematics and arm function in persons post stroke: a pilot randomized controlled trial

BACKGROUND

Robot-based rehabilitation for persons post-stroke may improve arm function and daily-life activities as measured by clinical scales, but its effects on motor strategies during functional tasks are still poorly investigated. This study aimed at assessing the effects of robot-therapy versus arm-specific physiotherapy in persons post-stroke on motor strategies derived from upper body instrumented kinematic analysis, and on arm function measured by clinical scales.

METHODS

Forty persons in the sub-acute and chronic stage post-stroke were recruited. This sample included all those subjects, enrolled in a larger bi-center study, who underwent instrumented kinematic analysis and who were randomized in Center 2 into Robot (R_Group) and Control Group (C_Group). R_Group received robot-assisted training. C_Group received arm-specific treatment delivered by a physiotherapist. Pre- and post-training assessment included clinical scales and instrumented kinematic analysis of arm and trunk during a virtual untrained task simulating the transport of an object onto a shelf. Instrumented outcomes included shoulder/elbow coordination, elbow extension and trunk sagittal compensation. Clinical outcomes included Fugl-Meyer Motor Assessment of Upper Extremity (FM-UE), modified Ashworth Scale (MAS) and Functional Independence Measure (FIM).

RESULTS

R_Group showed larger post-training improvements of shoulder/elbow coordination (Cohen's d = - 0.81, p = 0.019), elbow extension (Cohen's d = - 0.71, p = 0.038), and trunk movement (Cohen's d = - 1.12, p = 0.002). Both groups showed comparable improvements in clinical scales, except proximal muscles MAS that decreased more in R_Group (Cohen's d = - 0.83, p = 0.018). Ancillary analyses on chronic subjects confirmed these results and revealed larger improvements after robot-therapy in the proximal portion of FM-UE (Cohen's d = 1.16, p = 0.019).

CONCLUSIONS

Robot-assisted rehabilitation was as effective as arm-specific physiotherapy in reducing arm impairment (FM-UE) in persons post-stroke, but it was more effective in improving motor control strategies adopted during an untrained task involving vertical movements not practiced during training. Specifically, robot therapy induced larger improvements of shoulder/elbow coordination and greater reduction of abnormal trunk sagittal movements. The beneficial effects of robot therapy seemed more pronounced in chronic subjects. Future studies on a larger sample should be performed to corroborate present findings.

TRIAL REGISTRATION

www.ClinicalTrials.gov NCT03530358. Registered 21 May 2018. Retrospectively registered.

Learning and transfer of complex motor skills in virtual reality: a perspective review

The development of more effective rehabilitative interventions requires a better understanding of how humans learn and transfer motor skills in real-world contexts. Presently, clinicians design interventions to promote skill learning by relying on evidence from experimental paradigms involving simple tasks, such as reaching for a target. While these tasks facilitate stringent hypothesis testing in laboratory settings, the results may not shed light on performance of more complex real-world skills. In this perspective, we argue that virtual environments (VEs) are flexible, novel platforms to evaluate learning and transfer of complex skills without sacrificing experimental control. Specifically, VEs use models of real-life tasks that afford controlled experimental manipulations to measure and guide behavior with a precision that exceeds the capabilities of physical environments. This paper reviews recent insights from VE paradigms on motor learning into two pressing challenges in rehabilitation research: 1) Which training strategies in VEs promote complex skill learning? and 2) How can transfer of learning from virtual to real environments be enhanced? Defining complex skills by having nested redundancies, we outline findings on the role of movement variability in complex skill acquisition and discuss how VEs can provide novel forms of guidance to enhance learning. We review the evidence for skill transfer from virtual to real environments in typically developing and neurologically-impaired populations with a view to understanding how differences in sensory-motor information may influence learning strategies. We provide actionable suggestions for practicing clinicians and outline broad areas where more research is required. Finally, we conclude that VEs present distinctive experimental platforms to understand complex skill learning that should enable transfer from therapeutic practice to the real world.

End-point kinematics using virtual reality explaining upper limb impairment and activity capacity in stroke

BACKGROUND

For evaluation of upper limb impairment and activity capacity, Fugl-Meyer Assessment of Upper Extremity (FMA-UE) and Action Research Arm Test (ARAT) are recommended to be included in stroke trials. To improve the understanding of mechanisms of motor recovery, and differentiate between restitution and compensation, kinematic analysis is also recommended for assessment of upper limb function after stroke.

AIM

To determine the extent to which end-point kinematic variables obtained from the target-to-target pointing task were associated with upper limb impairment or activity limitation as assessed by traditional clinical scales in individuals with stroke.

METHODS

Sixty-four individuals, from acute stage up to one year after stroke, were included from the Stroke Arm Longitudinal study at the University of Gothenburg (SALGOT) cohort. They performed a target-to-target pointing task in a virtual environment using a haptic stylus which also captured the kinematic parameters. Multiple linear regression was done to determine the amount of variance explained by kinematic variables on FMA-UE and ARAT scores after controlling for confounding variables.

RESULTS

Mean velocity and number of velocity peaks explained 11 and 9% of the FMA-UE score uniquely and 16% when taken together. Movement time and number of velocity peaks explained 13 and 10% of the ARAT score respectively.

CONCLUSION

The kinematic variables of movement time, velocity and smoothness explain only a part of the variance captured by using clinical observational scales, reinforcing the importance of multi-level assessment using both kinematic analysis and clinical scales in upper limb evaluation after stroke.

TRIAL REGISTRATION

The trial was registered with register number NCT01115348 at clinicaltrials.gov , on May 4, 2010. URL: https://clinicaltrials.gov/ct2/show/NCT01115348 .