The muscle is named via Latin, from Greek γαστήρ (gaster) 'belly' or 'stomach' and κνήμη (knḗmē) 'leg', meaning 'stomach of the leg' (referring to the bulging shape of the calf).

Some anatomists consider both to be a single muscle—the triceps surae or "three-headed [muscle] of the calf"—since they share a common insertion via the Achilles tendon.

The gastrocnemius is primarily involved in running, jumping and other "fast" movements of leg, and to a lesser degree in walking and standing.

The signal is passed through the internal capsule and decussates, or crosses, in the medulla oblongata, specifically in the lateral corticospinal tract.

Anatomical abnormalities involving the medial head of gastrocnemius muscle result in popliteal artery entrapment syndrome.

In a 1967 EMG study, Herman and Bragin concluded that its most important role was plantar flexing in large contractions and in rapid development of tension.