Bimanual motor skill learning and robotic assistance for chronic hemiparetic stroke: a randomized controlled trial

Using robotic devices might improve recovery post-stroke, but the optimal way to apply robotic assistance has yet to be determined. The current study aimed to investigate whether training under the robotic active-assisted mode improves bimanual motor skill learning(biMSkL) more than training under the active mode in stroke patients. Twenty-six healthy individuals(HI) and 23 chronic hemiparetic stroke patients with a detectable lesion on MRI or CT scan, who demonstrated motor deficits in the upper limb, were randomly allocated to two parallel groups. The protocol included a two-day training on a new bimanual cooperative task, LIFT-THE-TRAY, under either the active or activeassisted modes(where assistance decreased in a pre-determined stepwise fashion) with the bimanual version of the REAplan? robotic device. The hypothesis was that the active-assisted mode would result in greater biMSkL than the active mode. The biMSkL was quantified by a speed-accuracy trade-off(SAT) before(T1) and immediately after(T2) training on days 1 and 2(T3 and T4). The change in SAT after 2 days of training(T4/T1) indicated that both HI and stroke patients learned and retained the bimanual cooperative task. After 2 days of training, the active-assisted mode did not improve biMSkL more than the active mode(T4/T1) in HI nor stroke patients. Whereas HI generalized the learned bimanual skill to different execution speeds in both the active and active-assisted subgroups, the stroke patients generalized the learned skill only in the active subgroup. Taken together, the active-assisted mode, applied in a pre-determined stepwise decreasing fashion, did not improve biMSkL more than the active mode in HI and stroke subjects. Stroke subjects might benefit more from robotic assistance when applied "as-needed." This study was approved by the local ethical committee(Comité d'éthique médicale, CHU UCL Namur, MontGodinne, Yvoir, Belgium;Internal number: 54/2010, Eudra CT number: NUB B039201317382) on July 14, 2016 and was registered with ClinicalTrials.gov(Identifier: NCT03974750) on June 5, 2019.