Effect of Push-Off Facilitation by Protrusions Attached to the Insole Tip on Lower Limb Joint Range of Motion and Step Length during Brisk Gait

Abstract

This study investigated the effect of push-off facilitation by protrusions attached to the insole tip （PRT insole） on lower limb joint range of motion （ROMs） and step length （SL） during brisk gait. Sixteen healthy males performed treadmill walking under three different conditions: CONTROL walked as usual, INST was instructed to extend SL with an enhancing push-off at the terminal stance phase, and PRT was asked to extend SL while attempting to step on protrusions of PRT insoles. A 3D-motion capture system with infrared cameras was used to analyze the gait. In the INST condition, the hip and ankle ROMs and SL increased only during push-off attention. In the PRT condition, although the hip joint ROM increased only during the use of PRT insoles, the ankle joint ROM and SL increased significantly during and immediately after the use of the insoles compared to before use. This increase in ROM may be due to increased plantar flexion during the terminal stance phase. Therefore, the present results suggest that the PRT insole may be used to extend SL by enhancement of push-off during warm-up exercises, and that the effect of SL extension may remain even without the insole during subsequent exercises.