The toes of most shoes, especially sneakers, bend ever so slightly upward. While that curve, called a toe spring, can make walking easier and more comfortable, it may also weaken feet and potentially open them up to some common (and painful) foot-related problems.

That’s the conclusion reached by Harvard evolutionary biologist Daniel E. Lieberman, his former undergraduate student Oliver B. Hansen ’19, and two former postdoctoral researchers, Freddy Sichting and Nicholas B. Holowka, who studied toe springs and their effect on the biomechanics of walking.

The scientists found that the more curved a toe spring is, the less power the foot inside the shoe has to exert when pushing off from the ground while walking. That means foot muscles are doing less work, and this, the researchers hypothesize, may have consequences.

“It stands to reason that if the foot muscles have to do less work, then they’re probably going to have less endurance given that many thousands of times a day you push off on your toes,” said Lieberman, the Edwin M. Lerner II Professor of Biological Science and senior author on the paper. The work on toe springs is described in Scientific Reports.

The researchers say this potential weakness could make people more susceptible to medical conditions like plantar fasciitis — a common, hard to repair, and painful inflammation of the thick, web-like band of tissue that connects the heel bone to the toes.

Release date: 17 September 2020
Source: Harvard University