Physical function and wheelchair-operating ability among caregivers aged 75 years and older: a controlled observational study

Purpose This study evaluated the ability of older caregivers (aged ≥75 years) to operate a manual wheelchair across environmental barriers and examined associations with physical function.Methods Fifty-six women participated, including 36 older adults (aged ≥75 years) and 20 younger adults. Physical function was assessed using grip strength, mobility, balance, and locomotive syndrome (LS) stage. Wheelchair-operating ability was evaluated across level and uneven terrains—specifically through slope ascent, side-slope navigation, front-caster lifting, and wheel-recovery tasks—while participants pushed a manual wheelchair loaded with a 60-kg dummy.Results Compared with younger adults, older adults showed poorer physical function and wheelchair-operating performance across most tasks. Notably, 22.2% of older adults could not lift the front casters over a 10-cm step. Among older adults, a higher LS stage independently correlated with poorer wheelchair-operating performance during normal-speed slope ascent (β = 0.474, p = 0.002), fast slope ascent (β = 0.317, p = 0.030), and fast side-slope navigation (β = 0.579, p < 0.001). Furthermore, weaker left-hand grip strength was associated with poorer slope-ascent performance at both normal (β = −0.357, p = 0.014, adjusted R2 = 0.48) and fast speed (β = −0.413, p = 0.004, adjusted R2 = 0.53). Conversely, no physical function variables significantly predicted performance during the front-caster lifting or wheel-recovery tasks.Conclusion Age-related declines in mobility and upper-limb strength may compromise wheelchair-operating safety. Targeted training, instruction, assistive technologies, and ergonomic wheelchair designs may improve safety and mobility. Barrier-free environments also remain essential for supporting community participation in ageing societies.