Structure/Morphology
The calcaneal (Achilles) tendon is the long tendon that attaches the muscle bellies of the triceps surae muscles (i.e., the soleus and the medial and lateral heads of the gastrocnemius muscle) to the posterior surface of the calcaneus.
The proximal end of the tendon begins in the middle of the leg, where the fibers of the triceps surae muscles begin to converge and form this single tendon.
Proximal to its insertion site, the calcaneal tendon spirals, which results in the gastrocnemius fibers inserting laterally on the calcaneus and the soleus fibers inserting medially.
Related parts of the anatomy
Anatomical Relations
The calcaneal tendon is located:
- anterior (deep) to the subcutaneous calcaneal bursa;
- posterior (superficial) to the ankle joint, flexor hallucis longus muscle, and the bursa of calcaneal tendon.
In some individuals, the plantaris muscle does not insert directly onto the posterior surface of calcaneus, but instead inserts onto it indirectly by merging its tendon with the calcaneal tendon.
Function
The calcaneal tendon is the thickest and strongest tendon in the body and attaches the muscle bellies of the triceps surae muscles to the posterior surface of the calcaneus. This insertion site allows the triceps surae muscles to be able to plantarflex the foot at the ankle joint.
List of Clinical Correlates
- Calcaneal tendinopathy
- Calcaneal rupture
- Calcaneal tendinitis
- Haglund’s deformity
- Calcaneal tendon reflex