Tendon · Lower leg

Achilles tendon

Tendo calcaneus

The thickest and strongest tendon in the body, and the one that has to survive the most load — every step, hop and sprint is transmitted through it. It is the shared tendon of the calf: gastrocnemius and soleus merge into a single flat band that twists slightly as it descends and anchors into the back of the heel bone. That twist, plus the fact that the tendon has no muscle to protect it, is why it is so often the site of overuse pain rather than sudden failure. Pain here is usually a story about load added faster than the tendon could adapt.