Burden-Reducing Shoes with Elastomer-Embedded Flexible Joint

A new type of shoe with elastomer-embedded flexible joint (EEFJ) comprising a C-shaped spring and an embedded elastomer was proposed herein. The EEFJ was designed to support the plantar flexion muscle moments and to move freely in the other direction. Theoretical analysis and strength test were conducted for the EEFJ. According to the results of the strength test, the minimum moment at 10° in the plantar flexion was 8.9 Nm. This moment achieved the requirement moment (3.6 Nm). The maximum moment at 45° in the dorsiflexion was 0.022 Nm. The moments in the plantar flexion were significantly stronger than those in the dorsiflexion. We prototyped burden-reducing shoes by installing the EEFJ on the outside of the ankle joint. The total weight of a cuff, an aluminum plate, and the EEFJ for one leg was 183 g.