Peroneus Longus Muscle

The peroneus longus is the longer and more superficial of the two peroneus muscles, arising much more superiorly on the shaft of the fibula. The narrow peroneus longus extends from the head of the fibula to the sole of the foot. Its tendon can be palpated and observed proximal and posterior to the lateral malleolus.

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Peroneus Longus Muscle Anatomy

Distal to the superior fibular retinaculum, the common sheath shared by the peroneus muscles splits to extend through separate compartments deep to the inferior fibular retinaculum. The peroneus longus passes through the inferior compartment, inferior to the fibular trochlea on the calcaneus, and enters a groove on the antero-inferior aspect of the cuboid bone. It then crosses the sole of the foot, running obliquely and distally to reach its attachment to the 1st metatarsal and 1st (medial) cuneiform bones. When a person stands on one foot, the peroneus longus helps steady the leg on the foot.

See Also: Peroneus Brevis
See Also: Lateral Compartment of the Leg

Origin

The peroneus longus muscle arises from head of fibula, upper 1/2 – 2/3 of lateral fibular shaft surface and anterior and posterior intermuscular septa of leg.

Insertion

Its tendon inserts on the plantar posterolateral aspect of medial cuneiform and lateral side of 1st metatarsal base.

Innervation

Peroneus Longus muscle is innervated by the superficial peroneal nerve (L5, S1, S2). It may also receives additional innervation from common or deep peroneal nerves (L5, S1, S2)

Blood Supply

It’s supplied by the anterior tibial and peroneal arteries.

Action

It acts to everts the foot and plantar flexes ankle joint; it also helps to support the transverse arch of the foot.

Clinically, the peroneus longus tendon can become dislocated, subluxated or ruptured. Surgical treatment correlates with improved full return to activity and improved patient-reported outcome scores in symptomatic patients. A personalized, comprehensive rehabilitation program is necessary to optimize the recovery of surgically treated peroneal tendon tears and ruptures. Since most peroneal tendon tears occur in young active patients and athletes, early return to activity is of utmost importance.

An isolated tear is more commonly found in the peroneus brevis muscle but can also occur in the peroneus longus. Non-operative treatment includes NSAIDs, ice, rest, immobilization, and physical therapy. Steroid injections can also be used in patients refractory to previously mentioned treatments. If conservative treatment fails, operative treatment can include an open debridement, synovectomy, and arthroscopic peroneal tendoscopy for tendinitis.

For peroneal tendon tears, operative treatment includes an end-to-end repair, side-to-side anastomosis, or Pulver Taft weave with chronic tears, as well as allograft reconstruction.

The peroneus longus is important in plantar flexion and eversion of the foot at the ankle. For this reason, it is tested during the physical exam to assess the range of motion and motor strength of the ankle. Weakened or absent motor strength can indicate muscle or nerve damage to the peroneus longus and/or peroneus brevis muscles, the two muscles of the lateral compartment of the lower limb.

References & More

1. Clinically Oriented Anatomy – 8th Edition
2. Lezak B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb: Calf Peroneus Longus Muscle. [Updated 2023 Aug 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK546650/
3. van Dijk PA, Lubberts B, Verheul C, DiGiovanni CW, Kerkhoffs GM. Rehabilitation after surgical treatment of peroneal tendon tears and ruptures. Knee Surg Sports Traumatol Arthrosc. 2016 Apr;24(4):1165-74. [PubMed]