Overview
It has a lateral and a medial head, between which the superficial digital flexor arises. Cattle also have a small soleus (m. soleus), which joins the gastrocnemius tendon. The common calcanean tendon (the "Achilles tendon") is formed by the tendon of the gastrocnemius, that of the superficial digital flexor and the tarsal tendons of the biceps femoris and semitendinosus.
Origin
Lateral and medial supracondylar tuberosities of the femur.
Insertion
Calcaneal tuber (tuber calcanei).
Action
Extends the tarsus and flexes the stifle.
Innervation
Tibial nerve (n. tibialis).
Clinical relevance
- Spastic paresis ("Elso heel"): in young cattle, from a few weeks to several months old, the gastrocnemius undergoes progressive spastic contraction. The hock becomes straight and overextended and the limb is held caudally, sometimes without bearing weight. It has a hereditary component; it is treated by tibial neurectomy or tenotomy, and affected animals should not be used for breeding.
- Gastrocnemius rupture occurs in downer cows or cows straining to rise: the hock drops and the animal stands with the tarsus close to the ground.
- In downer cow syndrome, prolonged recumbency causes ischaemic myopathy of the pelvic limb muscles.