Injury to the superficial peroneal nerve will result in motor loss of which muscle?
**Core Concept**
The superficial peroneal nerve is a branch of the common peroneal nerve, responsible for innervating the muscles of the lateral compartment of the leg. It is a mixed nerve, providing both motor and sensory innervation to the region.
**Why the Correct Answer is Right**
The superficial peroneal nerve primarily innervates the peroneus longus and peroneus brevis muscles, which are responsible for eversion of the foot. Injury to this nerve will result in weakness or paralysis of these muscles, leading to difficulty in performing activities that require foot eversion, such as standing on the edge of a flat surface. The peroneus longus muscle also plays a role in ankle stabilization.
**Why Each Wrong Option is Incorrect**
**Option A:** The deep peroneal nerve, not the superficial peroneal nerve, innervates the tibialis anterior muscle, which is responsible for dorsiflexion of the foot.
**Option B:** The posterior tibial nerve, a branch of the sciatic nerve, innervates the muscles of the posterior compartment of the leg, including the flexor digitorum longus and flexor hallucis longus muscles.
**Option C:** The sural nerve, a branch of the common peroneal nerve, provides sensory innervation to the lateral aspect of the foot and the little toe, but does not innervate any muscles.
**Clinical Pearl / High-Yield Fact**
The superficial peroneal nerve is often damaged in injuries to the lateral aspect of the knee or ankle, such as a lateral malleolus fracture or a peroneal nerve stretch.
**Correct Answer:** C.