Does Embodiment Matter to Biomechanics and Function? A Comparative Analysis of Head-Mounted and Hand-Held Assistive Devices for Individuals with Blindness and Low Vision

Visual assistive technologies like Microsoft’s Seeing AI can improve access to environmental information for persons with Blindness or Low Vision (pBLV). Yet, the physical and functional implications of different device embodiments remain unclear. Eleven pBLV participants used Seeing AI on a hand-held smartphone and a head-mounted ARx Vision system to perform six activities of daily living, while movements were captured with Xsens motion capture. Functional outcomes included task time, success rate, and attempt count; biomechanical measures included joint range of motion, angular path length, working volume, and movement smoothness. The head-mounted system generally reduced upper-body movement and task time, especially for document-scanning tasks, whereas the hand-held system yielded higher success rates for small or curved text. Both embodiments are viable, differing in physical demands and ease of use. Incorporating biomechanical measures into assistive technology evaluations can inform designs optimizing user experience, balancing functional efficiency, physical sustainability, and intuitive interaction.