Common Peroneal (Fibular) Nerve (Foot Drop)

DC 8521Neurological38 CFR 4.124a, DC 8521

Damage to the common peroneal nerve (also called the common fibular nerve) at the knee, which controls foot dorsiflexion (lifting the foot) and eversion (turning the foot outward). Complete injury causes foot drop — the inability to lift the foot during walking, causing a characteristic slapping gait. The common peroneal nerve wraps around the fibular head just below the knee and is vulnerable to compression and trauma. This is a lower extremity nerve with no major/minor distinction.

How the VA rates this condition

The VA rates this condition based on how much it affects your ability to work and carry out daily activities. The examiner will focus on the functional limitations your condition causes, not just the diagnosis itself.

Diagnostic code

DC 8521

Rating range

10% – 40%

Rating levels

Rating criteria are defined in 38 CFR 4.124a, DC 8521. This guide presents a plain-language summary and is not a substitute for the full regulatory text. Always consult a VSO or VA-accredited attorney for case-specific advice.

Rating Levels

You have complete paralysis of the common peroneal nerve — total foot drop with inability to lift the foot or turn it outward. You require a brace to walk.

What the VA looks for

Complete foot drop documented on examination
Inability to dorsiflex the foot or extend the toes
Complete sensory loss on dorsum of foot
Marked muscle atrophy in anterior and lateral compartments
EMG confirming complete common peroneal denervation

Common Pitfalls

⚠Not differentiating common peroneal nerve injury from L4-L5 radiculopathy — both can cause foot drop, but the treatment and rating approach differ. EMG and nerve conduction studies are essential to localize the lesion.
⚠Not documenting the need for an ankle-foot orthosis (AFO) — if you need a brace to prevent foot drop while walking, this strongly supports severe or complete nerve damage.
⚠Not connecting the injury to service — the common peroneal nerve is vulnerable where it wraps around the fibular head. Leg fractures, prolonged kneeling (common in military), tight casts, and blast injuries can all damage this nerve.
⚠Not reporting falls — foot drop causes tripping and falls, especially on stairs and uneven ground. Documenting falls establishes the safety impact and functional severity.

Related DBQ Forms

DBQ Peripheral Nerves Conditions

View evidence checklist →See secondary conditions →

Condition Rating Guides

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Common Peroneal (Fibular) Nerve (Foot Drop)

How the VA rates this condition

Diagnostic code

DC 8521

Rating range

10% – 40%

Rating levels

Rating Levels

You have complete paralysis of the common peroneal nerve — total foot drop with inability to lift the foot or turn it outward. You require a brace to walk.

What the VA looks for

Complete foot drop documented on examination
Inability to dorsiflex the foot or extend the toes
Complete sensory loss on dorsum of foot
Marked muscle atrophy in anterior and lateral compartments
EMG confirming complete common peroneal denervation

Common Pitfalls

⚠Not differentiating common peroneal nerve injury from L4-L5 radiculopathy — both can cause foot drop, but the treatment and rating approach differ. EMG and nerve conduction studies are essential to localize the lesion.

⚠Not documenting the need for an ankle-foot orthosis (AFO) — if you need a brace to prevent foot drop while walking, this strongly supports severe or complete nerve damage.

⚠Not connecting the injury to service — the common peroneal nerve is vulnerable where it wraps around the fibular head. Leg fractures, prolonged kneeling (common in military), tight casts, and blast injuries can all damage this nerve.

⚠Not reporting falls — foot drop causes tripping and falls, especially on stairs and uneven ground. Documenting falls establishes the safety impact and functional severity.