Effectiveness of Shock-Absorbing Insole for High-Heeled Shoes on Gait: Randomized Controlled Trials

This study was carried out to identify the influence of a shock-absorbing insole, developed by the author for use with high-heeled shoes, on walking. The research design included single-blind randomized parallel groups; namely, a group of 26 participants who wore the shock-absorbing insoles and another group of 26 participants who did not wear the insoles, both carried out walking while wearing 7 cm high-heels. During walking, plantar pressure analysis (via in-shoe plantar pressure measurements), surface electrode electromyography (surface EMG), gait analysis, subjective comfort evaluation, and functional movement (functional mobility) analysis were carried out. In order to compare the two groups, statistical verification (paired t-test) was performed. Wearing the shock-absorbing insole with the high-heeled shoes improved posture stability during walking, as well as increasing the walking speed. In addition, the heel pressure, the pressure of the front foot at the inner side, and the shock ability were decreased. For these reasons, the wearers reported higher comfort. Changes in the muscle activities of the tibialis anterior muscle (TA) and the gastrocnemius muscle (GA) heightened the stability of the ankle joints. Overall, the proposed shock-absorbing insole for use with high-heeled shoes improved the postural stability when walking, as well as improving the distribution of pressure on the soles. A decrease in the diverse side-effects of wearing high-heeled shoes can thus be expected.