The Achilles tendon is the strongest and thickest tendon in the body, connecting the gastrocnemius, soleus and plantaris to the calcaneus. It is approximately 15 centimeters (5.9 inches) long and begins near the middle portion of the calf. Contraction of the gastrosoleus plantar flexes the foot, enabling such activities as walking, jumping, and running. The Achilles tendon receives its blood supply from its musculotendinous junction with the triceps surae and its innervation from the sural nerve and to a lesser degree from the tibial nerve.
Other mechanisms by which the Achilles can be torn involve sudden direct trauma to the tendon, or sudden activation of the Achilles after atrophy from prolonged periods of inactivity. Some other common tears can occur from overuse while participating in intense sports. Twisting or jerking motions can also contribute to injury.
Depending on the severity of the tear, surgery may be needed to repair an Achilles tear.