Age and gender differences in the perception and use of soft vs. rigid exoskeletons for manual material handling.

We investigated age and gender differences in the perception and use of soft (Apex) vs. rigid (Paexo Back) passive back-support exoskeletons (BSE) for repetitive lifting and lowering. A gender-balanced sample of 20 young (18-30 years) and 16 old (45-60 years) individuals were recruited. In the first session, participants' self-reported maximum acceptable load (MAL) was assessed using a psychophysical approach. Changes in muscle activity and kinematics due to BSE use in repetitive lifting/lowering tasks were also assessed. Overall, both BSEs increased MAL (by ∼7%), and reduced trunk extensor muscle activity across all groups (by ∼7-18%), compared to the control condition. Both BSEs promoted more squatting postures, increased quadriceps muscle activity (by ∼34%) and abdominal muscle activity during asymmetric tasks (by 5-20%). Some age and gender differences were significant, particularly for the trunk kinematics when using the Apex. Future work should include more diverse user groups in studying willingness to adopt BSEs and characterising their consequent effects on the body.