Background: The purpose of this study was to assess the effects of textured insoles on static upright posture before and after lower limb muscle fatigue. Textured insoles used contained small and non-deformable pebbles of various sizes that are able to stimulate a major number of mechanoreceptors. It was inserted inside footwear.
Methods: Ten healthy young adults participated in the study (mean age 26.1±3.07 years). They were asked to stand on a force platform in four sensory states: vision, no vision, with and without natural plantar stimulation. For each sensory state the subjects underwent a single 30-second trial in pre-fatigue and post-fatigue conditions. Muscle fatigue was induced by 60 seconds of continuous jumping. Center of pressure displacement, sway velocity, antero-posterior and medio-lateral sway velocity were measured using force platform.
Results: Textured insoles had a stabilizing effect on balance compared to control insoles. Textured insoles significantly reduced CoPDISP and VA/P levels in closed eyes pre-fatigue condition. Post-fatigue all postural parameters improved in both vision and no vision conditions.
Conclusions: Textured insoles with rigid stimulation significantly improved CoPDISP, independently of vision, supplying relevant and complete sensory information and improving balance in fatigue conditions.