The peroneal nerve is a branch of the sciatic nerve and supplies movements and sensation to the lower leg, foot and toes. The peroneal nerve innervates the tibialis anterior, extensor digitorum longus, extensor hallucis longus and the peroneus tertius which are responsible for dorsiflexing the foot and extending the toes. It is one of the more exposed nerves in the body, wrapping around the outside of the knee and resting on the fibula. Due to the positioning of the nerve it leaves it vulnerable to injury. Common causes of injury include:
- Trauma or injury to the knee
- Fibula Fracture
- Regularly crossing your legs
- Regularly wearing high constrictive boots
- Tight casts or bandages
- Pressure from prolonged periods of sleeping or coma,
- The knee being placed in unusual positions during surgical procedures
The main symptoms that arise from peroneal nerve injuries affect gait and balance, which can impact lower limb function and quality of life depending on the severity of the nerve damage. Symptoms include; foot drop, decreased sensation or numbness on the top of the foot and lower leg, toes dragging when walking, slapping gait pattern, weakness of the feet and ankles and loss of muscle mass.
Treatment for peroneal nerve injuries includes surgical intervention if medically indicated to release or repair the peroneal nerve. Depending on the severity of gait abnormalities an ankle foot orthosis may be used to aid walking and reduce the impact that foot drop has on the gait cycle. Exercise therapy remains a primary treatment option to assist with symptom management as well as improving function and quality of life. A tailored exercise rehabilitation programme will generally include a variety of muscular activation and strengthening exercises for muscles of the foot, ankle and lower leg. Stretching and mobility exercises helps prevent joint and muscular stiffness, and proprioception and gait retraining exercises.
Specific interventions that have shown to be beneficial in exercise rehabilitation of peripheral nerve injuries include mirror box therapy and contralateral strength training. Mirror box therapy includes the use of mirrors to copy the unaffected limb whilst visually blocking the effected limb. The mirror is used to retrain the brain as to how the effected limb should move by encouraging it to copy the unaffected limb. The contralateral strength training effect is the transfer of muscle performance to the untrained limb following training of the contralateral (unaffected) side. The mechanism of this training effect is not fully understood but likely to involve increased motoneuron output rather than muscular adaptations. Where by neuromuscular adaptations in the control system for the trained limb can be accessed by the opposite limb or increased neural drive in the trained limb induces adaptations in the control system for the opposite limb.
For more information relating to Peroneal Nerve Injuries or treatment methods contact Absolute Balance today.
Lisa Wallbutton (BSR, MClinicalExPhysiol(Rehab))
Accredited Exercise Physiologist (AEP) (ESSAM)
Manca, A., Pisanu, F., Ortu, E., De Natale, E., Ginatempo, F., Dragone, D., . . . Deriu, F. (17-20). Isokinetic cross-training effect in foot drop following common peroneal nerve injury. Isokinetics & Exercise Science , 2015.