A ruptured Achilles tendon often can be very debilitating and, in many cases, surgery is required to repair the tendon directly. The Achilles is the most commonly injured tendon in the foot. It is located on the back of the leg and is a thick, fibrous piece of tissue that connects the calf to the heel bone. Injury most often happens as a result of playing sports, although other causes are possible. Four to six weeks of casting and physical therapy are mainstays of treatment after a complete Achilles tendon tear.