A peroneal nerve injury, also known as peroneal neuropathy may be caused by direct trauma to the outer knee with symptoms of numbness, tingling or weakness in the foot.
Medically reviewed by Dr. Chaminda Goonetilleke, 21st Dec. 2021
Peroneal nerve injury symptoms
Symptoms of a peroneal nerve injury, also known as peroneal neuropathy include:
- Numbness or tingling in the front and or side of the lower leg.
- There will be decreased sensitivity when touching these areas.
- Weakness in lifting the foot upwards and turning it outwards may be experienced and in severe cases.
- Foot drop will occur where the foot cannot be lifted up enough to clear the floor when walking.
- A slapping gait may be seen as the foot slaps on the ground when walking.
The Common Peroneal Nerve (also known as common fibular nerve) has superficial and deep branches.
The superficial branch supplies the peroneal muscles which plantarflexes (push foot downwards) and everts the foot.
The deep branch supplies the anterior compartment of the leg (TIbialis anterior). It helps to dorsiflex (pull the foot upwards) and inverts (turn the foot inwards).
Causes of peroneal nerve injury
This nerve may be injured in a number of ways including injury to the outside of the knee. This is because the nerve is very close to the skin.
Swelling, inflammation or infection can also injure the peroneal nerve as can repeated pressure on the outside of the knee. For instance from sitting with legs crossed in tight clothing.
Similar symptoms may be present due to compression of the nerve at a higher level, usually either at the nerve root in the lumbar spine (L4 & S2) or in the buttocks.
Treatment of peroneal nerve contusion
Treatment depends on the cause of your injury.
Knee contusion related
Peroneal nerve symptoms caused by an acute injury to the outer knee may resolve once your knee injury has healed and any swelling or pressure on the nerve has dispersed.
If your injury is caused by repetitive compression from training or work related activities then this should be addressed.
Symptoms caused by damage to the nerve itself (i.e. from a fracture or dislocation) are more difficult to treat, although, in all but the most severe cases. The damage will usually heal itself, although this can be a very slow process.
In the meantime, physical therapy may be beneficial in improving muscle strength and control. Exercises to stretch and strengthen the muscle of the lower leg may help improve the condition.