Achilles Tendonitis Risk Factors and Causes

Poorly conditioned athletes are at the highest risk for developing Achilles tendonitis, also sometimes called Achilles tendinitis. Participating in activities that involve sudden stops and starts and repetitive jumping (e.g., basketball, tennis, dancing) increases the risk for the condition. It often develops following sudden changes in activity level, training on poor surfaces, or wearing inappropriate footwear.

Achilles tendonitis may be caused by a single incident of overstressing the tendon, or it may result from a series of stresses that produce small tears over time (overuse).

The condition also may develop in people who exercise infrequently and in those who are just beginning an exercise program, because inactive muscles and tendons have little flexibility because of inactivity. It is important for people who are just starting to exercise to stretch properly, start slowly, and increase gradually.

Patients who develop arthritis in the heel have an increased risk for developing Achilles tendonitis. This occurs more often in people who middle aged and older.

In some cases, a congenital (i.e., present at birth) condition causes Achilles tendonitis. Typically, this is due to abnormal rotation of the foot and leg (pronation), which causes the arch of the foot to flatten and the leg to twist more than normal.

This condition causes the lower leg muscles (e.g., gastrocnemius, soleus) to stretch more than normal. Like a rubber band, the further the muscles stretch, the tighter they become. The force on the Achilles tendon and the heel bone increases, resulting in Achilles tendonitis. Because the arch of the foot naturally flattens over time, especially in athletes, Achilles tendonitis often develops later in life.

Women who wear high-heeled shoes often and switch to sneakers for exercise also can develop Achilles tendonitis. The Achilles tendon and lower leg muscles gradually adapt to a shortened position because the shoes prevent the heel from stretching all the way to the ground.

When this occurs, wearing sneakers or flat shoes forces the Achilles tendon to stretch further than it is accustomed to, causing inflammation. If high heels are worn everyday, stretching should be done every morning and night to keep the Achilles tendon lengthened.

Publication Review By: Hai-En Peng, D.P.M.

Published: 01 Jan 2000

Last Modified: 23 Sep 2014