Effects of a Passive Lower-Limb Exoskeleton on Plantar Pressure Distribution and Postural Stability During Prolonged...

Background: Prolonged occupational standing is associated with increased plantar pressure, impaired postural stability and fatigue, contributing to lower-limb musculoskeletal disorders. Passive lower-limb exoskeletons have been proposed as an ergonomic solution to reduce mechanical load without external power. Objective: To evaluate the effects of a passive lower-limb exoskeleton (Chairless Chair^® 2.0) on plantar pressure distribution, postural stability, perceived fatigue and user satisfaction in workers exposed to prolonged standing. Methods: A quasi-experimental pre-post study was conducted in 25 asymptomatic restaurant workers. Participants performed static standing and walking trials on a baropodometric platform with and without the exoskeleton. Plantar pressures were recorded in static and dynamic conditions and postural stability was assessed by centre-of-pressure (COP) displacement and velocity. Perceived fatigue was measured with the Borg CR10 scale, and usability and comfort with the QUEST 2.0 questionnaire. Repeated-measures ANOVA and non-parametric tests (p < 0.05) were applied. Results: Compared with standard footwear, the exoskeleton significantly reduced plantar contact area and peak and mean plantar pressures during standing and walking. Posturographic analysis revealed a significant effect of condition on COP-related variables, with significantly lower oscillation and velocity measures observed in the exoskeleton condition. Perceived fatigue remained low to moderate and did not differ significantly between tasks (p = 0.96). QUEST 2.0 scores reflected high perceived effectiveness, ease of use and comfort, although device weight was the least favourable characteristic. Conclusions: The Chairless Chair^® 2.0 improved plantar pressure redistribution and was associated with lower COP displacement and velocity values without increasing perceived exertion. The device was generally well accepted by participants, supporting its potential use as an ergonomic aid in occupations requiring prolonged standing.