Individual Differences in Body Mass, Biological Sex, and Physical Fitness Affecting Human-Exoskeleton Interactions

Prior research investigating human-exoskeleton interactions showed significant variabilities among users in their physical, physiological, and cognitive responses associated with exoskeleton use. Individual exoskeleton users’ varying anthropometric and demographic characteristics may lead to large inter-individual variability. This study examined the impacts of exoskeleton users’ body mass index (BMI), sex, and physical fitness on perceived exoskeleton fit, exoskeleton-related pain, and physical and cognitive task performances while wearing upper- and lower-body exoskeletons. The results indicated that participants with higher BMI were more likely to experience pain with an upper-body exoskeleton. Sex differences were also observed, with men experiencing more pain when using a lower-body exoskeleton. Frequent physical activity and cardio training were positively correlated with pain experienced with an upper-body exoskeleton. While the impacts were not universal across different exoskeleton types, the current findings offer insights into the potential causes of individual variability in human-exoskeleton interactions.