Wrist Range of Motion Variability for Adaptive Exoskeleton Design: A Study on users with and without SCI or ALS

Wrist exoskeletons hold promise for assisting individuals with motor impairments such as spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). However, existing designs often lack adjustability and adaptability to the individual wrist range of motion (ROM), which is crucial for safety and usability. This study presents a literature review of the wrist abduction/adduction ROM measurements in individuals without motor disability and individuals with motor impairments and highlights on the measurement details and findings. This study also investigates wrist abduction/adduction ROM in three user groups: fifteen individuals without any motor disability, two individuals with ALS, and five with SCI. The experimental procedure included the completion of three trials, where ROM was measured and analyzed to determine intergroup variability. Individuals without motor disability exhibited the largest ROM range, while SCI users had reduced adduction. Our findings highlight the need for user-specific ROM considerations in exoskeleton design to optimize functionality and prevent discomfort or injury. This study contributes to the development of adjustable and user-centered wrist exoskeletons, addressing safety and usability gaps in the current state of the art.