The peroneus longus, a lateral (lower) leg muscle, is also known as the fibularis longus muscle.

It is situated in the lateral or peroneal compartment of the leg, lateral to (covering) the peroneus brevis muscle, lateral and posterior to the extensor digitorum longus muscle, and its proximal third anterior to the soleus muscle. Its distal tendon runs through the lateral and central plantar compartments of the foot.

The peroneus longus connects the fibula bone (its bony origin), the medial cuneiform bone, and the 1st metatarsal bone (its bony insertion).

In addition to the bones that connect with the peroneus longus muscle; the fascia cruris, the anterior intermuscular septum of the leg, the lateral intermuscular septum of the leg, the lateral intermuscular septum of the foot, and the medial intermuscular septum of the foot are musculoskeletal components of the same anatomical unit.

Illustration Referrals:
Agur (1999): 362-365, 367, 370, 371, 374, 375, 381, 384, 387, 388, 396-398, 402, 403, 406, 409, 410
Gilroy (2008): 373, 392-396, 404, 410-415, 419, 432, 442, 444, 445, 447, 449-451