Like many products, shoes are designed to make things a little easier on our bodies. Many shoes, especially sneakers, have a slight upwards bend in the toe area of the shoe. This area, known as the toe spring, is designed to make walking easier and more comfortable. However, researchers believe this design could also be having unintended consequences for our feet.
According to research out of Harvard, this toe spring could also weaken the foot and open it up to some painful foot-related problems. These findings were pointed out by Harvard evolutionary biologist Daniel Lieberman and colleagues during their studies on toe springs and their effects on the biomechanics of walking.
What they uncovered is that the more curved a toe spring is, the less power the foot inside the shoe needs to exert when pushing off the ground. While it’s convenient for our foot, it can also lead to de-conditioned muscles and other problems, said Lieberman.
“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.
Muscle De-Conditioning
They believe this muscle de-conditioning could lead to an increased likelihood of plantar fasciitis, a condition categorized by painful inflammation in the tissue that connects your heel bone to your toes.
“One of the biggest problems in the world today of people’s feet is plantar fasciitis,” Lieberman said. “We think that what happens is that people are relying on their plantar fascia to do what muscles normally do. When you get weak muscles and the plantar fascia has to do more work, it’s not really evolved for that and so it gets inflamed.”
Freddy Sichting, a post-doctoral researcher and first author of the paper on toe springs and foot biomechanics, offered sentiments similar to ours when we say that “we weren’t born with shoes, so we shouldn’t over-rely on them.”
“From an evolutionary perspective, wearing modern shoes that have arch supports, cushioning, and other supportive features is a very recent phenomenon,” said Sichting. “Several lines of evidence suggest that weak foot muscles may be partly a consequence of such features. In our research, we were interested in a nearly ubiquitous element of modern shoes that has not been studied before: the upward curvature at the front of the shoe.”
The reason behind the foot issues is likely linked to a problem with the metatarsophalangeal (MTP) joints. Over time, limited strengthening of these joints can weaken these areas and open people up to injury.
“By reducing moments at the MTP joints, toe springs likely relieve the intrinsic foot muscles of some of the work necessary to stiffen these joints,” the team wrote in the study. “These small differences in muscle work likely add up to substantial differences over time when considering that the average individual in industrialized countries takes 4,000 to 6,000 steps per day. Thus, habitually wearing shoes with toe springs could inhibit or de-condition the force-generating capacity of intrinsic foot muscles.”
They hope to confirm their findings with future studies, but for now, their research should serve as a reminder that we shouldn’t spend all day in comfy shoes, otherwise we may be weakening key muscle groups. Go barefoot around the house, and work in some targeted foot strengthening exercises when at the gym.
