Changes in Arm Kinematics of Chronic Stroke Individuals Following "Assist-As-Asked" Robot-assisted Training in Virtual and Physical Environments: A Proof-of-concept Study

Introduction: In this proof-of-concept study, we introduce a custom-developed robot-assisted training protocol, named "Assist-As-Asked", aiming at improving arm function of chronic stroke subjects with moderate-to-severe upper extremity motor impairment. The study goals were to investigate the feasibility and potential adverse effects of this training protocol in both physical and virtual environments.

Methods: A sample of convenience of four chronic stroke subjects participated in 10 half-hour sessions. The task was to practice reaching six targets in both virtual and physical environments. The robotic arm used the Assist-As-Asked paradigm in which it helped subjects to complete movements when asked by them. Changes in the kinematics of the reaching movements and the participants' perception of the reaching practice in both environments were the outcome measures of interest.

Results: Subjects improved their reaching performance and none of them reported any adverse events. There were no differences between the two environments in terms of kinematic measures even though subjects had different opinions about the environment preference.

Conclusions: Using the Assist-As-Asked protocol in moderate-to-severe chronic stroke survivors is feasible and it can be used with both physical and virtual environments with no evidence of one of them to be superior to the other based on users' perspectives and movement kinematics.