Enhancing postural stability and gait in older adults: The role of somatosensory foot orthoses on varied inclined terrains

This study aimed to investigate the effects of somatosensory foot orthoses (SFO) with tactile stimulating knobs on postural stability and gait in older adults across varied inclined terrains. Twenty-three participants walked on level, uphill, and downhill terrains and performed standing tasks with eyes open and closed, using either SFO or flat foot orthoses (FFO) on an instrumented treadmill. Key parameters measured included center of pressure (CoP) trajectories, ground reaction forces, and plantar pressures. SFO reduced mediolateral CoP displacement during 15-65% of the stance phase on downhill terrain (<i>p</i> < 0.001). Vertical ground reaction forces increased at 35-45% (<i>p</i> = 0.001) of stance on level terrain and decreased at 5-10% (<i>p</i> = 0.020) and 55-60% (<i>p</i> = 0.025) of stance on uphill terrain. Maximum plantar pressure decreased with SFO at the inner forefoot [level (<i>p</i> = 0.007), uphill (<i>p</i> = 0.001), and downhill (<i>p</i> < 0.001)], toes [uphill (<i>p</i> = 0.003) and downhill (<i>p</i> = 0.019)], and medial forefoot [uphill (<i>p</i> < 0.001) and downhill (<i>p</i> = 0.013)] on varied terrains. These findings underscore the importance of incorporating stimulating knobs into foot orthoses to enhance somatosensory feedback and improve plantar pressure distribution. Further studies are warranted to confirm and expand clinical applications for populations with balance impairments or increased fall risks.