A guiding principle to optimize crutch

Conventional underarm crutches have been ubiquitous for rehabilitation over the centuries. A disadvantage of the design is that they tend to unintentionally waste the users' energy and increase pain and discomfort. Insight to dynamical crutch walking reveals an optimized design principle that harnesses the dissipated energy arising from the interaction between the crutches, the ground and the user's body. Based on the principle, we design and manufacture novel crutches that are able to store the above dissipated energy and release it at the subsequent heel-strike so as to propel the body forward in an optimized means. It eases off the user's pains and maximize the efficiency of the user's metabolic energy while maintaining a feasible crutch walking. The new product is low cost and reliable that easily accesses to the existing market. The proposed principle is extendable to other rehabilitation devices and walking robots.