Effects of Passive Arm Support Exoskeleton on Static Postural Balance

Work-related musculoskeletal disorders (WMSDs) pose a significant health risk in industries, particularly those involving overhead work. Passive Arm-support Exoskeletons (ASEs) have emerged as potential interventions to mitigate WMSDs, but their impact on postural balance and fall risks remains uncertain. This study aimed to investigate how a passive ASE influences static postural balance under varying weight conditions and load locations. A preliminary experiment involving six healthy young males was conducted, employing a 3 × 3 × 3 within-subjects design with Intervention (without exoskeleton, exoskeleton without supportive force, and exoskeleton with supportive force), Weight (2.5 kg, 5 kg, and 7.5 kg), and Load location (Low, Mid, High) as independent variables. The experiment utilized a Wii balance board to measure participants’ body sway by calculating the normalized mean velocity of center of pressure (COP) during static holding tasks. Results indicated that wearing ASE with the supportive force turned on significantly reduced postural sway by 23.2% and 21.7% across all task conditions compared to when the exoskeleton was not worn and when the supportive force was turned off, respectively. Specifically, the magnitude of this decrease was contingent on both the weight being carried and the specific location of the load. In conclusion, this pilot study suggests that the supportive force provided by the ASE has the potential to enhance static postural balance, with effectiveness influenced by factors such as weight condition and load location. Future work should involve larger sample sizes and better control over gripping posture, incorporating alternative load representations and considering the ASE’s torque profile.