Dissociating motor learning from recovery in exoskeleton training post-stroke

Schweighofer, Nicolas; Wang, Chunji; Mottet, Denis; Laffont, I.; Bakhti, Karima; Reinkensmeyer, David J.; Rémy-Néris, Olivier

doi:10.1186/s12984-018-0428-1

Cited by 40 publications

(54 citation statements)

References 44 publications

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“…This rather high variability might be because the VPIT allows heterogeneous task completion strategies and the haptic device being able to render only up to 3.3 N of haptic feedback, which can lead to an unstable haptic rendering of the virtual reality environment. Also, the variability might be influenced by a visuomotor transformation from the end-effector to the virtual reality environment that has to be learned throughout multiple repetitions of the task ( Figure SM5), as also observed in other virtual reality-based assessments [74].…”

Section: Clinimetric Properties Of the Vpit Metricsmentioning

confidence: 67%

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

Kanzler

Schwarz

Held

et al. 2020

Preprint

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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 movements and grip forces during a goal-directed manipulation task without arm weight support. The aim of this work was to evaluate the potential and robustness of the VPIT metrics to inform on sensorimotor impairments in arm and hand, and especially identify the functional relevance of the detected impairments. 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 and compared to conventional clinical scales of impairment and activity limitations. Additionally, the robustness of the VPIT metrics was investigated by analyzing their clinimetric properties (test-retest reliability, measurement error, and learning effects). 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, moderate to high significant correlations between conventional scales of activity limitations and the VPIT metrics were found, thereby indicating their functional relevance when grasping and transporting lightweight objects as well as 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 poststroke individuals with mild to moderate deficits. This allows better identifying impairments with high functional relevance and can contribute to optimizing the functional benefits of neurorehabilitation interventions.Retrospectively registered: clinicaltrials.gov/ct2/show/NCT03135093 2

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Section: Clinimetric Properties Of the Vpit Metricsmentioning

confidence: 67%

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

Kanzler

Schwarz

Held

et al. 2020

Preprint

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“…Moreover, intact motor pathways for voluntary motor control (e.g. corticospinal tract) are most likely involved in the execution of steady-state motor commands (Schweighofer et al, 2018), given our finding that individuals with poorer voluntary motor control also exhibited a more atypical structure of their steady state muscle activity. Such associations were not found for the execution of corrective responses (de Kam et al, 2018), suggesting that the execution of corrective responses uses different circuitry, most likely at the level of the brainstem (Jacobs and Horak, 2007;Bolton, 2015).…”

Section: Partial Dissociation Between Recalibration and Execution Of mentioning

confidence: 82%

Cerebral contribution to the execution, but not recalibration, of motor commands in a novel walking environment

Kam

Iturralde

Torres-Oviedo

2019

Preprint

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Human movements are flexible as they continuously adapt to changes in the environment by updating planned actions and generating corrective movements. Planned actions are updated upon repeated exposure to predictable changes in the environment, whereas corrective responses serve to overcome unexpected environmental transitions. It has been shown that corrective muscle responses are tuned through sensorimotor adaptation induced by persistent exposure to a novel situation. Here, we asked whether cerebral structures contribute to this recalibration using stroke as a disease model. To this end, we characterized changes in muscle activity in stroke survivors and unimpaired individuals before, during, and after walking on a split-belt treadmill moving the legs at different speeds, which has been shown to induce recalibration of corrective responses in walking in healthy individuals. We found that the recalibration of corrective muscle activity was comparable between stroke survivors and controls, which was surprising given then known deficits in feedback responses post-stroke. Also, the intact recalibration in the group of stroke survivors contrasted the patients' limited ability to adjust their muscle activity during steady state split-belt walking compared to controls. Our results suggest that the recalibration and execution of motor commands in new environments are partially dissociable: cerebral lesions interfere with the execution, but not the recalibration, of motor commands upon novel movement demands.

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“…23,55 Also, sensor-based assessment metrics are often extracted from robot-assisted therapy platforms, 18,20,21 which can be biased through therapy-related learning effects. 56 Similar concepts to the VPIT have been proposed, but were not able to quantify hand impairments 52,57,58 or had limited clinical feasibility. 59 The possibility to assess UL sensorimotor disability has been thoroughly motivated and evaluated in a large population of healthy and neurological subjects.…”

Section: Clinical Relevance Of the Sensorimotor Profilesmentioning

confidence: 99%

An Objective Technology-based Assessment of Arm and Hand Sensorimotor Disability in Neurological Disorders

Kanzler¹,

Rinderknecht²,

Schwarz

et al. 2019

Preprint

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Background. Detailed assessments of upper limb disability are essential to understand and monitor sensorimotor recovery. Usually, multiple timeconsuming assessments are required to define a holistic sensorimotor profile of proximal (shoulder-elbow) and distal (wrist-hand) impairments and their impact on the capacity to perform activities. We propose and evaluate a novel physiologically-motivated computational framework for objectively assessing sensorimotor profiles in neurological patients using a single, rapid technologybased assessment involving goal-directed arm and hand movements. Methods.The Virtual Peg Insertion Test (VPIT) was administered to 121 healthy and 80 neurological subjects. The framework provides 25 kinematic and kinetic metrics expected to describe 12 sensorimotor components representative of ataxia and paresis and their influence on task performance, as well as one overall disability measure. The feasibility (protocol duration), structural validity (factor analysis and correlations ρ between sensorimotor components), concurrent validity (correlation with Action Research Arm Test; ARAT), and discriminant validity (comparing healthy controls and patients, and patients with different disability levels) were evaluated. Results. The median VPIT protocol duration was 16.5min in neurological patients. The sensor-based metrics could unambiguously be grouped into 12 mostly independent (median |ρ|=0.14) components. Ten components showed significant differences between healthy and impaired subjects and nine components indicated clear trends across disability levels, without any ceiling effects. The VPIT overall disability measure Technology-based Upper Limb Disability Assessment and ARAT were moderately correlated (ρ=−0.53, p<0.001). Conclusions. This work demonstrates the possibility to rapidly, holistically, and objectively assess proximal and distal sensorimotor impairments and their influence on the capacity to perform activities with a single assessment.

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Dissociating motor learning from recovery in exoskeleton training post-stroke

Cited by 40 publications

References 44 publications

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

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

Cerebral contribution to the execution, but not recalibration, of motor commands in a novel walking environment

An Objective Technology-based Assessment of Arm and Hand Sensorimotor Disability in Neurological Disorders

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