Muscle Anatomy

peroneus tertius

The peroneus tertius, a slender muscle, is located on the anterior aspect of the lower leg, contributing to ankle and foot movements.

Arising from the lower third of the fibula and the interosseous membrane, the peroneus tertius originates from the lateral side of the lower leg.

The muscle inserts into the dorsal base of the fifth metatarsal, extending down towards the base of the first metatarsal.

The primary function of the peroneus tertius is dorsiflexion and eversion of the foot. It assists in pulling the foot upward and outward, contributing to the stability of the ankle joint. While not as robust as some other muscles in the lower leg, the peroneus tertius plays a role in maintaining balance during walking and other weight-bearing activities.