Effects of stiffened midsole of running shoes on push-off energy during running was evaluated. Increase in elastic energy stored in stiff
midsole could be altered to propulsion energy during push-off phase and it could also help reduce negative work at metatarsophalangeal (MTP) joint during push-off phase. Appropriate bending stiffness of running shoes was also predicted not to perturb natural movement of the MTP joint during human running.