Unequal assistance? A systematic review of demographic representation and outcome differences in exoskeleton studies

Occupational exoskeletons are increasingly adopted to mitigate work-related physical demands, yet demographic variability in effectiveness remains unclear. This systematic review evaluated demographic reporting in arm- and back-support exoskeleton (ASE/BSE) studies and synthesized evidence on demographic-related outcome differences in response to exoskeleton-use. A total of 191 articles (2019-2024) were analyzed for age, sex, race/ethnicity, anthropometry, device type, and setting. Twenty-five studies incorporated demographic variables in statistical analysis; 24 enabled a best-evidence synthesis of sex-specific effects on muscle activity, kinematics, and subjective responses. Quality was appraised using a modified Downs and Black tool. Most studies were laboratory-based with passive devices, and predominantly young male (∼78%) participants; none reported race/ethnicity, and anthropometric diversity was limited. While methodological quality was generally high, sample representativeness and justification were often lacking. Moderate evidence indicated larger reductions in trunk extensor activity for females using BSEs, while evidence for other demographic effects was insufficient. The limited demographic inclusivity of exoskeleton research limits generalizability. Future research should prioritize diverse recruitment and explore how demographic factors influence device efficacy to ensure equitable design and implementation.