Projecting the New Body: How Body Image Evolves During Learning to Walk with a Wearable Robot

Advances in wearable robotics challenge the traditional definition of human motor systems, as wearable robots redefine body structure, movement capability, and perception of their own bodies. While these devices can empower the wearer's motor performance, there is limited understanding of how wearer s update their perception of body images, especially images in dynamic movements, while learning to use these modern devices. This study aimed to fill the gap by examining the changes of body image as individuals learned to walk with a robotic prosthetic l eg over multi - day training. We measured gait performance and perceived body images via Selected Coefficient of Perceived Motion (SCoMo) after each training session. Based on human motor learning theory extended to wearer - robot systems, w e hypothesized that learning the perceived body image when walking with a robotic leg co - evolves with the actual gait improvement and becomes more certain and more accurate to the actual motion. Our result confirmed that motor learning improved both physical and perceived ga it pattern towards normal, indicating that via practice the wearers incorporated the robotic leg into their sensorimotor systems to enable wearer - robot movement coordination. However, a persistent discrepancy between perceived and actual motion remained, l ikely due to the absence of direct sensation and control of the prosthesis from wearers. Additionally, the perceptual overestimation at the later training sessions might limit further motor improvement. These findings suggest that enhancing the human sense of wearable robots and frequent calibrating perception of body image are essential for effective training with lower limb wearable robots and for developing more embodied assistive technologies.