Article: The Influence of Foot Position in the Athelete

Rebecca L. Arner, MSPT, CSCS
BU Physical Therapy Center

Correct foot alignment and motion are essential for injury prevention, as well as for optimal performance. When a foot functions as it should, it allows the leg joints and muscles to work correctly, but even a very slight deviation or restriction can become magnified as we walk, run, cut, and jump. Many marathoners find themselves feeling great until their long runs work up above fifteen miles. Other athletes find themselves battling the same injury season after season or experience a new injury every time they recover from the previous. Still others try to improve their health by joining a gym, only to have back problems arise as soon as they get “in the swing of things.” If the foot is not functioning correctly, the body will eventually breakdown—in the form of ankle, knee, hip, and even back injuries. Individuals with chronic injuries such as knee tendonitis, ankle sprains, and nagging muscle strains often have a problem stemming from the foot.

Dorsiflexion is the motion describing the ankle’s bend to bring the foot up toward the body. The foot needs 10º to 15º of dorsiflexion in order to walk correctly, and at least 15º in order to run; otherwise, the foot will abnormally roll inward to compensate, causing malalignment and tension in the leg, particularly at the hip and knee. This often leads to problems such as shin splints and plantar fasciitis. To maintain adequate dorsiflexion requires a combination of joint motion and muscle length—particularly for the calf muscles. A problem will sometimes occur at the joint, requiring more specific intervention, but more often the problem occurs at the calf muscle. Making an effective calf stretch a daily priority is often enough to keep sufficient dorsiflexion.

Other important motions of the foot are pronation and supination. Pronation is the natural rolling-in motion of the foot 5-6º when it hits the ground, allowing shock to be absorbed. The foot then supinates, or rolls-out, to become rigid and strong as it pushes off again. For someone who overpronates, the foot rolls in the regular 5-6º and then keeps on going, preventing it from supinating, so that the foot is too loose when it pushes off. This individual often present with fallen arches, or “flat feet.” In this case, the surrounding muscles try to help the foot roll out, causing them to strain and fatigue. Because the muscles are not meant to do this additional work, it leads to problems like tendonitis of the knee or ankle.

If the foot does not pronate enough, it will be too rigid to absorb shock from the ground. This individual often presents with high arches. The force can be detrimental even in walking, but is multiplied at least five times in running. The ground shock travels up the leg, putting tremendous stress on the leg joints, all the way up to the back. It is estimated that approximately 50% of the population overpronates; and 25% of the population underpronates—meaning only 1 in 4 are in the correct position. Often these malalignments do not become a problem with mild walking, but when the demands of running, jumping, and cutting are greater, the malalignments surface as injuries.

There are many ways to combat the problems caused by the foot; one way is by addressing the muscles through strengthening, stretching and muscle-balancing. Essential to fighting malalignment is choosing the correct footwear. An overpronator may alleviate problems by getting a motion control or stability running shoe while an underpronator may need a more cushioned shoe. For more significant correction, or sports that do not utilize a running shoe, the problem may require the use of an orthotic device. Unlike an over-the-counter shoe insert, an orthotic is designed specifically for an individual’s foot. They are relatively light, but use strong material to correct the foot position and improve a person’s gait.

As we think about how to make ourselves more effective, as well as injury-free, we must respect the impact the foot has on the mechanics of our movement. We must prepare our bodies for the sports we choose. Preparation begins with allowing our “machine” to function correctly. Every step can either serve as corrective therapy or as damaging repetitive stress.