The calcaneal tendon, commonly referred to as the Achilles tendon, is a strong fibrous structure located on the posterior aspect of the lower leg. It is formed by the convergence of the gastrocnemius and soleus muscles and inserts onto the posterior surface of the calcaneus.[1] This tendon lies posterior to the ankle joint and is easily palpable beneath the skin at the back of the ankle.[1]

Structurally, the calcaneal tendon is composed predominantly of dense collagen fibers arranged to withstand high tensile forces.[2] The plantaris tendon often courses adjacent to the calcaneal tendon, although it contributes minimally to ankle movement.[3] A key spatial relationship exists between the calcaneal tendon and the calcaneal bursa, which lies between the tendon and the calcaneus and functions to reduce friction during movement.[1] The calcaneal tendon is the thickest and strongest tendon in the human body, reflecting its essential role in locomotion.[3]