A muscle along the outside of the leg that bends the foot outward at the ankle. The fibularis longus originates from the head and upper lateral surface of the fibular, runs in a bony groove along the bottom of the foot to attach on the other side at the base of the first metatarsal and the neighboring medial cuneiform bone, and acts to evert the foot; it is innervated by the superficial fibular nerve (L5, SI, S2).