The medial and lateral gastrocnemius muscle originates from the posterior aspect of the distal femur while the soleus muscle originates from the posterior aspect of the tibia, fibula, and interosseous membrane. These two tendons from the respective muscles coalesce to form the Achilles tendon, which inserts into the posterior surface of the calcaneus, distal to the calcaneal tuberosity.19 The Achilles tendon internally rotates 90 degrees onto itself, approximately 2 to 6 cm proximal to its insertion, where the posterior portion of the tendon becomes lateral. The area is also hypovascular according to angiographic studies done by both Lagergren20 and Carr and Norris,21 and this hypovascu-lar zone correlates with most noninsertional tendonitis, ten-dinosis, and ruptures. The Achilles tendon is not within a true synovial sheath but is covered by paratenon. The paratenon is penetrated anteriorly by the mesotenal arterioles that feed the tendon through vincula. Other sources of blood supply include the musculotendinous junction and osseous insertion. Deep to the tendon, the retrocalcaneal bursa sits superficial to the bone just proximal to the insertion. Another subcutaneous bursa between the tendon and the skin exists called the retrotendo-Achilles bursa or subcutaneous tendo-Achilles. These two areas can also be a source of irritation or inflammation.
During normal walking, at heel strike, the subtalar joint everts/pronates and the tibia internally rotates; simultaneously, passive knee extension causes external rotation through the tibia causing the Achilles tendon to absorb the stress. The Achilles is subjected to great stresses that may approach up to 10 times body weight depending on activity level.22 Biomechanical malalignments of the foot including "functional" overpronation and cavus foot have been implicated as causing increased stress on the Achilles tendon, thus inciting tendonitis.23
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Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.