What physical findings help to identify the approximate level of common lumbar nerve root lesions?
| Nerve | Sensory Loss | Motor Weakness | Reflex |
|---|---|---|---|
| L4 (5%) | Anterior leg, medial foot | Tibialis anterior (ankle dorsiflexion) | Patellar |
| L5 (67%) | Lateral leg, web of great toe | Extensor hallucis longus (great toe extension) | None |
| S1 (28%) | Posterior leg, lateral foot | Peroneus muscles (foot eversion) | Achilles |
Pearl: Note that 95% of nerve root impingement due to herniated disc disease affects the L5 or S1 nerve roots.
