The fibularis longus is a muscle located in the lateral compartment of the lower leg. It originates from the upper part of the fibula and runs down the leg, attaching to the base of the first metatarsal and the medial cuneiform bone in the foot. This muscle plays a crucial role in foot movement, particularly in eversion, which is the action of turning the sole of the foot outward. In addition to eversion, the fibularis longus assists in plantarflexion, helping to point the toes downward. It also provides support to the arch of the foot, contributing to overall stability during walking and running. Proper function of the fibularis longus is essential for maintaining balance and mobility.