Definition
The deep fibular nerve, also known as the deep peroneal nerve, is a branch of the common fibular (peroneal) nerve that supplies motor innervation to the anterior compartment muscles of the leg and sensory innervation to the skin between the first and second toes.
Overview
The deep fibular nerve descends along the anterior aspect of the leg, running deep to the extensor digitorum longus muscle. It traverses the anterior compartment, providing motor fibers to the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and fibularis tertius muscles. Distally, the nerve pierces the interosseous membrane to enter the dorsum of the foot, where it supplies sensory fibers to the web space between the hallux (big toe) and second toe. Clinically, injury to the deep fibular nerve can result in foot drop and loss of sensation in its cutaneous distribution.
Etymology/Origin
The term “fibular” derives from the Latin fibula, meaning “clasp” or “brooch,” which historically referred to the fibula bone of the lower leg. “Deep” distinguishes this branch from the superficial fibular nerve, which lies more laterally and provides cutaneous innervation to the lateral leg and dorsum of the foot. The alternative name “peroneal” originates from the Greek perone (πέραν), meaning “leg” or “shin,” and is still commonly used in clinical literature.
Characteristics
- Origin: Branches from the common fibular nerve near the neck of the fibula.
- Course: Runs deep to the extensor digitorum longus, alongside the anterior tibial artery, then passes through the distal leg via the anterior compartment and penetrates the interosseous membrane to reach the dorsum of the foot.
- Motor Innervation: Tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis (peroneus) tertius.
- Sensory Innervation: Skin of the first web space (between hallux and second toe).
- Clinical Significance: Damage may cause weakness of dorsiflexion (foot drop), impaired toe extension, and loss of sensation in the first dorsal web space. Diagnosis often involves electromyography, nerve conduction studies, and clinical examination.
- Variations: Anatomical variations may include differences in the exact branching pattern, occasional communication with the superficial fibular nerve, or variations in the extent of cutaneous distribution.
Related Topics
- Common fibular (peroneal) nerve
- Superficial fibular (peroneal) nerve
- Anterior compartment of the leg
- Tibialis anterior muscle
- Extensor hallucis longus muscle
- Foot drop (neuropathy)
- Nerve conduction studies
- Lower limb anatomy
- Peripheral neuropathy of the lower extremity