Leave it to science to find something else we are doing wrong in the modern world. This time the scientists are after our shoes, specifically those with toes slightly bent upward. According to new and limited research, such shoes might be making our feet weaker by reducing the amount of work required to walk.

The curved, upward design of shoe toes is known as toe spring. It is carefully calculated to make walking easier and more comfortable. After all, no one wants to walk around in uncomfortable shoes. But according to Harvard researchers Daniel Lieberman, Oliver Hansen, Freddy Sichting and Nicholas Holowka, toe spring could be messing with biology.

• Designed for Standing and Walking

The foot itself is clearly designed for standing and walking. Where walking is concerned, the portion of the foot science refers to as the toe box plays an important role. It provides forward and upward power as a person steps forward and follows through. Its importance is quite evident if you walk around without shoes and pay attention to how your foot pushes off at the toes.

Built-in toe spring apparently makes walking more efficient to the extent that less power is needed by the toe box. Unfortunately, that greater efficiency also requires less work by other muscles in the foot. The end result is less muscle mass and weaker feet.

• Toe Spring Isn’t in All Shoes

The researchers were quick to point out that not all shoes have toe spring built in. They focused a lot of their attention on sneakers, but even sneakers have varying degrees of toe spring. For example, if you were to look at the selection of women’s shoes at The Stockist in Salt Lake City, you would notice that some of their sneakers have flatter toes than others.

Where women’s shoes are concerned, you also have high heels to consider. High heels put a lot of pressure on the toes and balls of the feet during both standing and walking. But they also require a lot more work from the calf muscles. The Harvard researchers do not say if heels create the same kinds of problems as flatter shoes with toe spring, but it is hard to imagine they do not cause any problems at all.

• Toe Spring and Plantar Fasciitis

The Harvard study was motivated by a discussion between two of the researchers while on a run in Boston. They were talking about the mechanics of plantar fasciitis and how footwear might contribute to it. That led the men to each begin independent research in 2018. Two years later they think they have enough evidence to suggest that toe spring, and its effects on foot strength, may be behind many cases of plantar fasciitis.

Plantar fasciitis is inflammation in the plantar fascia, the fibrous tissue that connects the heel to the toes via the arch. The Harvard researchers surmised that weaker foot muscles require the tissue to do more work than it otherwise would, leading to inflammation and subsequent pain.

To test their theory, they enlisted the help of 13 volunteers who walked barefoot and in four pairs of specially made sandals. They walked on a treadmill equipped with sensors capable of measuring the amount of power required for each step. They discovered that the greater the toe spring, the less power was exerted by the foot.

Who knew? Modern footwear might be getting in the way of natural foot function, leading to weaker feet and a greater risk of plantar fasciitis. Maybe we would all be better off walking around barefoot.

Sheri Gill