The Achilles tendon is the largest tendon in the human body and can withstand forces of 1,000 pounds or more. It also is the most frequently ruptured tendon, usually as a result of a sports injury. Both professional and weekend athletes may suffer from Achilles tendonitis, a common overuse injury and inflammation of the tendon.
Events that can cause Achilles tendonitis may include:
Hill running or stair climbing.
Overuse, stemming from the natural lack of flexibility in the calf muscles.
Rapidly increasing mileage or speed when walking, jogging, or running.
Starting up too quickly after a layoff in exercise or sports activity, without adequately stretching and warming up the foot.
Trauma caused by sudden and/or hard contraction of the calf muscles when putting out extra effort, such as in a sprint.
Improper footwear and/or a tendency toward over-pronation.