Which peroneal muscle is NOT supplied by the superficial peroneal nerve?

The peroneus tertius muscle is indeed the correct answer to this question because it is primarily innervated by the deep peroneal nerve rather than the superficial peroneal nerve. The peroneus tertius is responsible for dorsiflexion and eversion of the foot, which is a role that distinguishes it from the other peroneal muscles.

The peroneus longus and peroneus brevis are both innervated by the superficial peroneal nerve, which is responsible for the sensation and motor functions of the lateral compartment of the leg, including eversion of the foot. Extensor digitorum longus, while also located in the anterior compartment and primarily responsible for extending the toes, is innervated by the deep peroneal nerve, but it is not one of the peroneal muscles.

Understanding the nerve supply and muscle function is crucial for both surgical considerations and anatomical studies in the field of medicine. The differentiation between the innervations and their respective muscle actions provides clear insight into how the peroneal muscles contribute to foot movement and stability.