The Effect Of Textured Plantar Surfaces On Postural Stability

Abstract

PURPOSE Balance training has become an integral part of therapeutic exercise interventions. Based on his clinical observations, Janda (1996) suggested using textured surfaces on the sole of the foot to stimulate the plantar cutaneous mechanoreceptors, increasing proprioceptive information into the central nervous system during balance training. The purpose of this pilot study was to determine the effects of a textured plantar surface on postural sway compared to a non-textured, flat surface. METHODS Eight orthopaedic physical therapy patients (4 males, 4 females, ages 22–58) performed a modified clinical test of sensory integration and balance (mCTSIB) using computerized posturography. Subjects stood without shoes (wearing socks) on a specially designed textured surface made out of PVC, with nodule width of 4.5 mm, height of 7.0 mm, and density of 9 nodules per 6.5 cm2. The mCTSIB consisted of three trials of each: eyes open flat surface, eyes open textured surface, eyes closed flat surface, and eyes closed textured surface. Sway velocity, sway amplitude, and sway index were compared on the flat and textured surfaces. RESULTS Due to the low number of subjects for this pilot study and high variability between subjects, statistical significance between the textured and flat surfaces could not be determined. However, comparison of descriptive data revealed that subjects demonstrated less increase in postural sway with eyes closed while standing on the textured surface compared to the flat surface (a higher sway index indicates more postural sway). The mean change in sway index with eyes closed between flat and textured surfaces was +.01, and +.11 with eyes open. Additionally, greater sway was observed during the flat condition as subjects went from the eyes open to eyes closed conditions. Mean change in sway index from eyes open to closed on textured was +.15, and +.23 on the flat surface. CONCLUSIONS The results of this pilot testing indicate a trend in which postural sway with textured surfaces only slightly increases as they subject moves from eyes open to eyes closed, compared to larger increases on flat surfaces. It is hypothesized that the textured surfaces help replace the loss of visual input to maintain postural stability by increasing afferent proprioceptive input into the sole of the foot. Consequently, the expected increase in postural sway from eyes open to eyes closed conditions may be attenuated by the textured surface. Future research should include additional subjects and investigate the effect of different textured surfaces on postural sway.