The Achilles tendon is formed by the insertion of the soleus and gastrocnemius. Plantaris inserts into the Achilles tendon. The tendon is surrounded by a para-tendon.Achilles tendinitis is an overuse injury of the Achilles tendon (from the musculotendinous junction of the gastrocnemius/soleus complex proximally to its insertion on the calcaneous) that causes pain in the posterior calf and heel.
Achilles tendinopathy causes chronic posterior ankle and heel pain that is worsened with activity. Runners show the highest incidence of non-insertional Achilles tendinopathy, which manifests as aching pain above the insertion of the Achilles, sometimes with associated swelling. In early stages, the pain occurs only with prolonged running, but as the disease advances pain may occur even at rest.
Insertional Achilles tendinopathy is seen in the athletic population but is more common as patients age and tendon degeneration occurs. Patients commonly localize their pain to the midline at the insertion of the Achilles on the calcaneus, although sometimes the pain is localized to the medial or lateral side.
Exercise, stair climbing, and running on hard surfaces tend to exacerbate the pain. Symptoms may occur initially with strenuous activities alone but often progress to pain being present at rest.
On examination, there is local tenderness and swelling. Predisposing factors are over pronation, lack of calf flexibility, and restricted dorsiflexion. Footwear may also contribute. Other contributory factors include a change in training pattern with increased exercise and reduced recovery.
Relative rest, ice, and elevation. An eccentric exercise program is most effective. The next stage is of functional and sport-specific rehabilitation. It is important to correct predisposing factors.