Effects of Height Increasing Heel Insole on Lower Extremity Joint Mechanics

High-heel shoes alter foot pressure distribution and lower extremity kinetic and kinematics. Unlike general women’s high-heeled shoes, height increasing heel insoles are cushioned, which may contribute to impact absorption. The purpose of this study is to compare the kinetic and kinematics of gaits with and without height increasing heel insoles. Two male subjects performed level walking under two conditions: wearing sports shoes with and without height increasing heel insoles which added additional 5 cm of the heel height (total 6 cm). The vertical ground reaction force (GRF), angle, moment, and power of ankle, knee, and hip during the stance phase of the right foot were calculated. As results, higher heel height decreased the GRF under the heel and increased the GRF under the forefoot. The overall plantarflexed foot posture during the stance phase led to the overall reduction in the peak plantar flexor moment, which was persisted into the terminal stance. Also, it limited the power output and concentric contraction of the plantar flexor muscles, including gastrocnemius and soleus. The angle, moment, and power of the knee and hip were similar for both heel height conditions. Walking with height increasing heel insoles caused changes in ankle kinetic and kinematics that begin in the early stance phase. Increased heel height altered entire ankle angle during the stance phase, caused more plantarflexion, and shortened gastrocnemius and soleus muscles. Therefore, the propulsive ability was restricted, leading to the decreases of ankle moment and power