Immediate and Sustained Effects on the Control of Myoelectric Prostheses by Action Observation Using Virtual Reality with Myoelectric Feedback

Abstract

Abstract Background Conventional myoelectric prosthesis (myo-prosthesis) training involves repetitive grasping and manipulation training, which requires considerable training time. It is necessary to develop a short and efficient myo-prosthesis training. The purpose of this study was to verify the immediate and sustained effects of action observation (AO) using virtual reality (VR) on myo-prosthesis control and clarify the effect of visual feedback of electromyogram (EMG) signals during AO using VR. Methods We evaluated 24 healthy right-handed individuals wearing a myo-prosthesis simulator in their dominant hands. We divided participants into three groups: VR video observation with EMG presentation during manipulation (VR+), VR video observation without EMG presentation (VR), and control group. We evaluated prosthetic control skills using the Gripping force adjustment test (GFAT) and Bowknot task immediately before and after AO and one week later. Additionally, we evaluated level of immersion, motivation, and enjoyment during AO. Results The rate of change in the GFAT one week after the intervention was significantly greater in the VR+ (p < 0.05, d = 1.32) and VR (p < 0.01, d = 2.34) than the control group. Immersion, motivation, and enjoyment were significantly higher in the VR + and VR than the control group. There was a significant main effect of the condition and time required for GFAT, although the post-hoc test showed no significant difference between VR + and VR groups. Conclusions AO using VR had a sustained effect on motor learning of myo-prosthetic control, despite EMG presentation. Therefore, AO using VR may maintain the ability to manipulate prosthesis once learned and might be used for future training of myo-prosthetic control.