Differential effects of augmented feedback in virtual reality environment for post-stroke arm rehabilitation

Abstract

Objective: To compare 2 types of augmented feedback (FB) provided during reaching training in the virtual reality environment (VR) for chronic stroke. Material and Method: Eight participants were assigned to receive either the knowledge of result (KR-mean age of 62.5 years) or the knowledge of performance (KP-mean age of 62.2 years) FB. Each participant underwent 12 training sessions which of each consisted of 75 point- to- target actions in the VR. They were instructed to perform the actions as fast and as accurate as possible. As for the FB in each session, the KR group heard the “peep” sound whereas the KP group saw the path of hand in a faded manner. The time of Wolf motor function test (WMFT) was evaluated at baseline, after the training, and 1 week later. The two factors repeated measure analysis of variance was used to analyze the data. Results: For the KP group, the total time of dexterity tasks in WMFT reduced significantly after the training, compared to that of the baseline. In contrast, the reduced time was not observed in the KR group. At the follow-up, only the KP group was able to maintain the improvement. Conclusion: Augmented KP feedback compared to the KR during reaching training in the VR greater improved dexterity of the paretic hand. The findings suggest differential benefits of FB for chronic stroke rehabilitation. The kinematic analyses are underway to understand the mechanism implementing the retained improvement at 1 week post training.