Nervus fibularis

Nervus Fibularis

The Nervus Fibularis, also known as the Peroneal Nerve, is a major nerve in the lower limb. It is one of the branches of the sciatic nerve, which is the largest nerve in the body. The Nervus Fibularis innervates the muscles of the lower leg and foot, providing both motor and sensory functions.

Anatomy

The Nervus Fibularis originates from the sciatic nerve, which is formed by the fusion of the ventral rami of the fourth and fifth lumbar nerves and the first, second, and third sacral nerves. The sciatic nerve then divides into two branches: the tibial nerve and the common fibular nerve. The common fibular nerve further divides into the superficial fibular nerve and the deep fibular nerve.

The superficial fibular nerve innervates the muscles on the lateral side of the leg, including the fibularis longus and fibularis brevis muscles. It also provides sensory innervation to the skin on the dorsum of the foot.

The deep fibular nerve innervates the muscles on the anterior side of the leg, including the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and fibularis tertius muscles. It also provides sensory innervation to the skin between the first and second toes.

Function

The Nervus Fibularis plays a crucial role in the movement and sensation of the lower leg and foot. The muscles innervated by the superficial fibular nerve are responsible for eversion of the foot and plantar flexion. These movements are important for maintaining balance and stability while walking or running.

The muscles innervated by the deep fibular nerve are responsible for dorsiflexion of the foot and extension of the toes. These movements are essential for lifting the foot off the ground during the swing phase of walking and for maintaining proper foot alignment during weight-bearing activities.

In addition to its motor functions, the Nervus Fibularis also provides sensory innervation to specific areas of the lower leg and foot. The superficial fibular nerve supplies sensation to the skin on the dorsum of the foot, while the deep fibular nerve supplies sensation to the skin between the first and second toes.

Clinical Significance

Damage or compression of the Nervus Fibularis can result in various symptoms and conditions. Common causes of Nervus Fibularis dysfunction include trauma, nerve entrapment, and certain medical conditions such as diabetes.

One of the most common conditions associated with Nervus Fibularis dysfunction is known as foot drop. Foot drop is characterized by the inability to dorsiflex the foot, resulting in a dragging or slapping gait. It can be caused by damage to the deep fibular nerve, leading to weakness or paralysis of the muscles responsible for dorsiflexion.

Treatment for Nervus Fibularis dysfunction depends on the underlying cause. Conservative measures such as physical therapy, orthotic devices, and medication may be used to manage symptoms and improve function. In severe cases, surgical intervention may be necessary to decompress or repair the affected nerve.