Written for Knee1 by Michelle Alford
Shoes were originally created to protect feet from unfavorable conditions, but little thought was given to the damaging effects shoes could have on the rest of the leg—especially the knee. The wrong shoes can cause knee injuries or contribute to the onset of knee osteoarthritis.
Recent studies have indicated that flip flops are good for knee health, running shoes are bad for knee health, and short heels may be better for overall leg health than flats. What all these studies agree on is that it is important to adopt a natural gait. Humans were walking upright for millions of years before the invention of shoes. The shape and movement of our feet have evolved for optimum efficiency and health, both while walking and running.
Christopher McDougal, author of the book Born to Run, claims that people came “pre-equipped” for running. McDougal advocates barefoot running, a movement that has gained momentum in the last five years. Modern running shoes weren’t developed until the 20th century. Prior to this, it was common to run in sandals, flats, or without shoes. McDougal believes that the high rate of injuries among runners is not caused by the body not being built to run, as was suggested by his doctors, but by running shoes teaching us the wrong way to run.
McDougal isn’t alone in this belief. According to an ongoing Harvard study, 75 percent of runners who wear shoes land heel first instead of midfoot or forefoot first. Heel-to-toe is more efficient for walking because it exerts less energy; however, when running, landing on the heel sends a shock through the body that’s two to three times the runner’s body weight. Landing midfoot or forefoot first doesn’t send this initial shock and total impact forces are up to 7 times lower than landing heel first.
Similarly, a 2010 study found that flip flops are healthier for the knee than clogs, stability shoes, or even walking shoes because they allow for natural foot movement. The foot’s flexibility helps to dissipate the pressure put on the knees when walking. Stiffer shoes prevent the foot from moving. Clogs and stability shoes also have higher heels, which could cause greater pressure on the knees.
Unsurprisingly, several studies have found that high heels are unhealthy for the knees. Research shows that both stilettos and wide heels increase the risk of developing osteoarthritis. In fact, wide heels may be worse for knee health because they feel more comfortable and women wear them longer. However, shoes with low heels—half-inch to three-quarter-inch—may be healthier than flats because they often conform better to the foot’s natural shape and allow for greater flexibility.
One new trend follows a back-to-nature approach. VIBRAM FiveFingers may produce the most unusual looking footwear currently on the market. These shoes fit feet like a pair of gloves. Their thin material surrounds the foot and toes, allowing barefoot-like movement while still protecting feet from the elements.
It’s not necessary to always wear the perfect shoes for your health. Sometimes the occasion calls for strappy high heels. However, it is important to be aware of how much pressure you’re putting on your knees and to pay attention to how you move, especially when running.
Discuss in the Knee1 forums
Photo: Paul Stocker