US Patent 8438757 Human locomotion assisting shoe

Embodiments of footwear, in particular, a shoe, sandal or boot, may reduce the effort and improve the performance of walking, running, hiking, marching, and various other gaits as well as jumping, hopping, and other motion involving the ankle and lower leg and Achilles tendon, through integration of force-carrying mechanisms within footwear that manage the forces and energy associated with such motion by productively harvesting and storing energy during dorsiflexion motion and releasing and returning energy during plantar flexion. One structural element of such footwear may comprise a top collar yoke having anterior and posterior gussets forming a channel and a shoe comprising a rotation zone supporting the channel and an elastomeric zone forming a tension spring via an elastomeric overlay or otherwise providing a spring-like member approximately parallel to and to assist the Achilles tendon during locomotion.