Achilles Tendon

Achilles tendon (tendo Achillis, tendo calcanea), calcaneal tendon. Old anatomists sometimes used legends and myths in creating terminology (see also Adam's apple); thus, the origin of the term 'Achilles tendon' is attributed by them to the following myth: the goddess Thetis, mother of Achilles, bathed her son in the infernal river Styx to make him invulnerable, but held him by the heel, which remained vulnerable; in this heel he was struck by an arrow from Paris. Translators from Arabic used the term 'Chorda magna Hippocratis': Hippocrates considered injuries to this tendon extremely dangerous. The Achilles tendon is the thickest and strongest of all the tendons of the human body. It is formed from the union of the tendons of the m. gastrocnemii and m. soleus; sometimes the tendon of the m. plantaris is also connected with them. The Achilles tendon attaches to the posterior surface of the calcaneal tuberosity. In its upper part it is wide and relatively thin, but as it descends it becomes narrower and thicker; reaching a point located 3.5-4 cm above the calcaneus, the tendon begins to gradually expand. Near the attachment site, a bursa is located beneath the tendon. The appearance of a narrowed area on the tendon, located near the calcaneal tuberosity, is explained by the fact that at this point the tendon fibers coming from each head of the gastrocnemius muscle cross each other, with the fibers coming from the medial head lying over the fibers coming from the lateral head. In some lower mammals, both muscular portions of the m. gastrocnemii exist independently of each other and also cross each other at the mentioned point. As an anomaly, both muscular portions of the m. gastrocnemii in humans may remain separated until their attachment to the calcaneus. The strong development of the calcaneus in humans depends, first, on the fact that it is the posterior support point of the foot on which the weight of the body presses, and second, because on this bone, through a single tendon, the entire force of the two powerful calf muscles - the m. gastrocnemii and m. soleus - is concentrated, which raise the weight of the human body during walking.