Lumbar Nerve Chart May 2026

The lumbar spinal nerves exit below their respective vertebrae (e.g., L4 nerve root exits between L4 and L5 vertebrae). They form the lumbar plexus , which gives rise to major motor and sensory nerves.

| Nerve Root | Major Nerve Branch | Motor Function | Sensory Area | |------------|------------------|----------------|---------------| | | Iliohypogastric, Ilioinguinal | Abdominal wall muscles | Suprapubic & upper gluteal skin | | L2 | Genitofemoral, Lateral femoral cutaneous, Obturator, Femoral | Hip flexion (psoas), thigh adduction | Anterior/medial thigh | | L3 | Femoral, Obturator | Knee extension (quadriceps), thigh adduction | Anterior/medial thigh, distal medial knee | | L4 | Femoral, Obturator | Knee extension, ankle dorsiflexion (via L4 also to tibialis anterior) | Medial lower leg, medial foot arch | Note: L5 is often included in lumbar radiculopathy charts but is technically part of the lumbosacral plexus. L5 root exits between L5–S1. 2. Common Lumbar Radiculopathy Patterns (Disc Herniation) | Herniated Disc | Affected Root | Typical Pain/ Sensory Loss | Motor Weakness | Reflex Loss | |----------------|---------------|----------------------------|----------------|--------------| | L3–L4 | L4 | Anterior thigh, medial lower leg | Quadriceps (knee extension) | Patellar reflex | | L4–L5 | L5 | Dorsum of foot, great toe | Great toe extension (extensor hallucis longus), foot drop (mild) | None (or internal hamstring) | | L5–S1 | S1 (not lumbar) | Lateral foot, sole | Plantarflexion (calf) | Achilles reflex | lumbar nerve chart