Fibular/peroneal muscles of the leg
Originating from the fibula and inserting on to the plantar surfaces of certain tarsal and metatarsal bones, these muscles play a role in the movements of the ankle joint and support of the foot. The functions of the fibular muscles are eversion and plantar flexion of the foot. Additionally, the fibularis longus muscle provides support to the arches of the foot. Both muscles are innervated by the superficial fibular nerve (L5, S1), and receive their blood supply from branches of the anterior tibial and fibular arteries.
This article will introduce you to the anatomy and function of the fibular muscles.
|Definition and function||Muscles of the lateral compartment of the leg that produce movements of the foot.|
|Muscles||Fibularis longus, fibularis brevis
|Innervation||Superficial fibular nerve (L5, S1)|
|Blood supply||Anterior tibial artery, fibular artery|
|Function||Plantar flexion, and eversion of the foot.
(Fibularis longus: supports longitudinal and transverse arches of the foot)
Fibularis (peroneus) longus muscle
The fibularis longus muscle originates from the head and proximal two-thirds of the lateral surface of the shaft of the fibula, as well as the adjacent surface of the intermuscular septum. It descends in an almost vertical fashion, giving off a narrow tendon midway through the lateral compartment of the leg. Its tendon passes behind the lateral malleolus and reaches the plantar compartment of the foot. It then courses anteriorly along the lateral edge of the foot, to finally insert on the plantar side of the medial cuneiform and first metatarsal bone.
The fibularis longus muscle is innervated by the superficial fibular (peroneal) nerve (L5, S1), a branch of the common fibular nerve.
The function of the fibularis longus muscle is to plantar flex and evert the foot. It also provides support to both the longitudinal and transverse arches of the foot.
Start with the fibular muscles of the leg by exploring our videos, quizzes, labelled diagrams and articles.
Fibularis brevis muscle
The fibularis brevis muscle originates from the distal two-thirds of the lateral surface of the fibula, and from the adjacent intermuscular septum. It is located deep and anterior to the fibularis longus muscle. The muscle fibers descend towards the foot, giving off a tendon just proximal to the ankle. The tendon passes behind the lateral malleolus and inserts to the tuberosity of the fifth metatarsal bone.
The fibularis brevis muscle is innervated by the superficial fibular (peroneal) nerve (L5, S1), a branch of the common fibular nerve.
The function of the fibularis brevis muscle is eversion of the foot.
Fibularis brevis anatomy is waiting for you here.
Want to learn more about the muscles of the lower limb? Composed of handy tables and diagrams listing attachments, innervation and functions for every muscle, our lower limb muscle anatomy chart will cut your study time in half.
In order to remember the muscles of the lateral compartment of the leg and their innervation, you can use the following mnemonic:
Fly Long Superficial Fly Boy
- Fibularis longus
- Superficial fibular nerve (innervation of both)
- Fibularis brevis
Are you here rather to solidify and test your knowledge on the fibular muscles? Try out our quiz!
When the superficial fibular nerve is paralysed the pronation of the foot is severely restricted. Thus the supination predominates so that during the lifting of the foot it simultaneously drifts medially (equinovarus position). When the affected patients try to walk it strikes how they place the lateral foot edge first in each step of the affected leg. Furthermore one may observe a shrinking of the lateral calf due to an atrophy of the peroneal muscles. Common causes for a lesion of the superficial fibular nerve include:
- injuries to the fibular head
- a too tight cast or inappropriate splint positioning of the leg
- polio (infantile paralysis)