1. NAME: DR SOLANKE ANDREW OLUSEGUN
TOPIC: PERONEAL SUPERFICIAL NERVE ALSO KNOWN AS
FIBULAR NEUROPATHY
2. Superficial Peroneal Nerve
The superficial fibular nerve is a nerve of the lower limb. In older texts, it is known as the
superficial peroneal nerve.
Nerve roots: L4-S1
Motor: Innervates the muscles in the lateral compartment of the leg.
Sensory: Supplies the vast majority of the skin over the dorsum of the foot, apart from the
webbing between the hallux and the second digit. It also supplies the anterior and lateral
aspect of the inferior third of the leg.
Course
The superficial fibular nerve is a terminal branch of the common fibular nerve.
It arises at the neck of the fibula, descending between the fibularis muscles and the lateral
side of the extensor digitorum longus. Here, it gives rise to motor branches, which supply the
fibularis longus and brevis. The nerve continues its descent, with a purely cutaneous function,
providing sensory innervation to the anterolateral aspect of the lower leg.
When the superficial fibular nerve reaches the lower third of the leg, it pierces the deep crural
fascia and terminates by dividing into the medial and intermedial dorsal cutaneous nerves.
These nerves enter the foot to innervate the majority of its dorsal surface.
3. Motor Functions
• The superficial fibular nerve supplies the fibularis longus and the fibularis brevis. These
muscles form the lateral compartment of the lower leg.
• They act to evert the foot, and thus act at the subtalar joint (eversion is the action of
turning the foot outwards). They also weakly contribute to plantarflexion, although this
action is mainly carried out by the gastrocnemius and the soleus muscles.
Sensory Functions
The superficial fibular nerve provides cutaneous innervation to certain areas of the leg and foot
(green in the diagram below):
• Innervates the skin over the anterolateral leg, via cutaneous branches directly from the
superficial fibular nerve.
• Innervates the skin of the dorsum of the foot (except the webbed space between the
hallanx and the 2nd digit), via the medial and intermedial dorsal cutaneous nerves.
4. What is the peroneal nerve?
The common peroneal nerve branches from the sciatic nerve. It includes the deep and
superficial peroneal branches. These nerves provide sensation to the anterior (front) and
lateral (side) parts of the legs and to the top of the feet. They innervate muscles in the legs
which lift the ankle and toes upward (dorsi flexion).
What is peroneal nerve injury (foot drop)?
A peroneal nerve injury (also called foot drop or drop foot), is a peripheral nerve injury that
affects a patient’s ability to lift the foot at the ankle. While foot drop injury is a neuromuscular
disorder, it can also be a symptom of a more serious injury, such as a nerve compression or
herniated disc.
Causes of peroneal nerve injury (foot drop)
Foot drop injury can be caused by an injury to the spinal cord or from other underlying
diseases, such as amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), or Parkinson's
disease. Sometimes, drop foot is a complication from hip replacement surgery, or other
injuries (e.g., knee or joint dislocation or fracture, herniated disc).
Symptoms of peroneal nerve injury (foot drop)
Inability to point toes toward the body (dorsi flexion)
Pain
Weakness
Numbness (on the shin or top of the foot)
Loss of function of foot
High-stepping walk (called steppage gait or footdrop gait)
5. Diagnosis of peroneal nerve injury (foot drop)
Diagnosis will include:
• A comprehensive clinical exam, including neurological exams
• Complete medical history
• Electrical testing
• Imaging studies, such as X-rays or high-resolution 3-T MRI (magnetic resonance
imaging)
Diagnosis is necessary to determine the cause of foot drop, so the appropriate treatment
plan, including a surgical option, is considered.
Treatment for peroneal nerve injury (foot drop)
Depending on the severity of your drop foot injury, your physician may recommend the
following:
Nonsurgical treatment for peroneal nerve injury (foot drop)
• Orthotics, including braces or foot splints, which may be custom-built into the
patient’s shoe
• Physical therapy, including gait training
Surgery for peroneal nerve injury (foot drop)
Surgical treatment for drop foot depends on the cause of the injury. A physician may
recommend decompression surgery, nerve sutures, nerve grafting, or nerve transfer or
tendon transfer.