Do Comfortable Shoes Come at a Cost?

Do your shoes’ toes point upward like these?

Study finds commonly used ‘toe springs’ could harm overall foot health

Those comfy kicks you’re wearing could be setting you up for foot conditions down the road, according to a new Harvard University study.

Take a moment to take a look at your shoes: If you see the toe area of your shoes bending slightly upwards, your footwear has what is called a “toe spring.” This feature allows the foot to roll forward while walking in an effort to make the motion more comfortable.

However, as published in Scientific Reports, researchers took on toe springs in a first-ever study and found that, the more curved a toe spring is, the less power the foot inside the shoe needs to exert pushing off the ground while walking. That means foot muscles are weakened by doing less work, making them more susceptible to medical conditions like plantar fasciitis: a very common, hard to heal, and painful inflammation on the bottom of the foot.

Researchers had 13 participants walk barefoot and in four pairs of custom-made sandals on a specially designed treadmill equipped with force plates and an infrared camera system to measure how much power is put into each step. Each pair of sandals had varying degrees of toe-spring angles—from 10 degrees to 40 degrees—designed to mimic the stiffness and shape found in commercially available shoes. Data showed that the propulsive force generated by the metatarsophalangeal joints (where your toes connect to the rest of your foot bones) decreases as the curve of the toe spring on the specially made sandals increased.

An example of toe spring in a walking shoe.

“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 the study’s lead author Dr. Daniel E. Lieberman, a professor of biological science, noting the research group plans on doing further research to explore possible needed shoe improvements. “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.”

Are your shoes helping or harming you? Are you experiencing pain when you walk or run? If you have questions about the best footwear for you, as well as overall foot and ankle health, the Department of Consumer Affairs’ Podiatric Medical Board of California licensees can help. Find out more about these professionals’ services, education, and licensure at www.pmbc.ca.gov, and to check a professional’s license, visit https://search.dca.ca.gov.

Related Reading: Household Chores Causing Back, Neck, or Foot Strain? Call a Professional; Step Into Podiatric Medicine