The Ankle Energetic Effect of Functional Insoles on Walking

Abstract Background：Although insoles made of various materials and shapes have been developed to improve performance in sport activities, few objective evaluations on their effectiveness have been conducted. We investigated the effect of insoles supporting the cuboid bone and anterior part of the calcaneus in healthy individuals.Methods:The subjects included 18 healthy males and females. They walked in standardized shoes with a flat insole (a flat insole made of polyurethane without an arched shape on the surface) and a functional insole (made of carbon and supporting the cuboid and anterior part of the calcaneus). We used a three-dimensional motion analysis device and a force plate to analyze gait and quantitatively compared the effect of functional insoles.Results:There was no difference in the parameters of gait analysis (walking speed, cadence, step length, stride length) between flat insoles and functional insoles. The functional insoles reduced ankle power without reducing walking ability. A comparison between Group A (n = 7), in which the left-right difference in ankle power was more than 20%, and Group B (n = 11), in which the left-right difference in ankle power was less than 20%, indicated that the use of functional insoles reduces the left-right difference of ankle power in the group with a larger difference in power.Conclusion：We believe that the use of functional insoles reduced ankle power without reducing walking ability and equalized left-right power. It may therefore reduce the burden on the muscles of the unilateral lower limbs and improve sport performance.Trial registration：The medical research ethics review committee for individuals at Gunma University (study number HS2017-229)　Registered 20 febluary 2018, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034362