Anatomy
Summary
The common peroneal nerve, also termed the fibular nerve, courses around the neck of the fibula and splits into two primary branches: the superficial peroneal nerve and the deep peroneal nerve. The superficial peroneal nerve provides sensory innervation to the dorsum of the foot, excluding the webspace between the hallux and the 2nd toe, and motor innervation to the lateral compartment muscles of the legÑthe peroneus longus and peroneus brevisÑresponsible for foot eversion. The deep peroneal nerve provides sensation to the webspace between the hallux and 2nd toe and motor innervation to the anterior compartment muscles of the leg, including the tibialis anterior, extensor hallucis longus, and extensor digitorum longus, thereby enabling foot dorsiflexion and toe extension.
The common peroneal nerve is the most frequently injured nerve in the lower extremity. These injuries are most likely to occur at the level of the fibula and are often due to compressive forces, such as stirrup positioning during surgical procedures or from extended periods of hospitalization. A defining feature of common peroneal nerve injury is steppage or equine gait, which manifests as foot drop, leading to impaired foot dorsiflexion and eversion.
Lesson Outline
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FAQs
The common peroneal nerve, also known as the fibular nerve, is a branch of the sciatic nerve that wraps around the neck of the fibula. It serves both sensory and motor functions in the lower leg and foot. After winding around the fibula, the nerve further divides into two main branches: the superficial peroneal nerve and the deep peroneal nerve, each responsible for specific sensory and motor activities.
The peroneal nerve, also known as the common fibular nerve, bifurcates into two main branches: the superficial peroneal nerve and the deep peroneal nerve. The superficial peroneal nerve is responsible for providing sensation to the dorsum of the foot, except for the webspace between the hallux and the second toe. It also innervates the muscles of the lateral compartment of the leg, specifically the peroneus longus and peroneus brevis, which are involved in everting the foot. The deep peroneal nerve supplies sensation to the webspace between the hallux and second toe, and innervates muscles of the anterior compartment of the leg such as the tibialis anterior, extensor hallucis longus, and extensor digitorum longus, facilitating foot dorsiflexion and toe extension.
The common peroneal nerve is the most commonly injured nerve in the lower extremity, largely because of its vulnerable location around the neck of the fibula. Injuries can result from factors like compression due to surgical stirrup positioning or from prolonged hospitalization. Such injuries often present clinically with a foot drop, characterized by a steppage (equine) gait.
'Foot drop' is a condition in which an individual has trouble lifting the front part of the foot. This is often due to an injury to the common peroneal nerve and results from paralysis in the muscles responsible for dorsiflexion and eversion of the foot. This can lead to an 'equine gait' that involves a high-stepping gait to prevent the toes from scraping the ground when walking, and develops as a compensatory mechanism to foot drop.
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