Which muscle is NOT innervated by the common peroneal nerve?

Which muscle is NOT innervated by the common peroneal nerve?

• A. Tibialis anterior
• B. Extensor digitorum longus
• C. Gastrocnemius
• D. Peroneus tertius

Answer: (C)

The common peroneal nerve supplies muscles in the front and outer parts of the leg (the anterior and lateral compartments), mainly those involved in dorsiflexion and foot eversion, via its branches. The gastrocnemius lives in the posterior compartment and is innervated by the tibial nerve, not the common peroneal. That’s why the gastrocnemius is not innervated by the common peroneal nerve, while the tibialis anterior, extensor digitorum longus, and peroneus tertius are all innervated by branches of the common peroneal nerve (specifically its deep branch).

The common peroneal nerve supplies muscles in the front and outer parts of the leg (the anterior and lateral compartments), mainly those involved in dorsiflexion and foot eversion, via its branches. The gastrocnemius lives in the posterior compartment and is innervated by the tibial nerve, not the common peroneal. That’s why the gastrocnemius is not innervated by the common peroneal nerve, while the tibialis anterior, extensor digitorum longus, and peroneus tertius are all innervated by branches of the common peroneal nerve (specifically its deep branch).