Patients with lower back pain due to irritation of the L5 nerve roots may have difficulty with dorsiflexion of the ankle and toes. Patients may also suffer from pain in the toes especially on pulling the toes upward. With such a movement, toe muscles may actually go into spasm with the toes in extension.
Weakness of toe extension will also produce difficulty in lifting the toes high off the floor when walking on the heels.
Testing the strength of the extensor hallucis longus is commonly performed for detection of presence of L5 nerve root irritation. The examiner tries to press down on the interphalangeal joint of the great toe while the patient tries to resist this movement by pulling into dorsiflexion.
Muscles which perform dorsiflexion of the toes are:
- extensor digitorum longus (deep peroneal nerve, L5, S1)
- extensor hallucis longus (deep peroneal nerve, L5, S1)
- extensor digitorum brevis. This muscle extends all the toes the metatarso- pharyngeal joints except that of the little toe. (deep peroneal nerve, L5, S1)