🔑 Key Learning
- Common peroneal → foot drop
- Superior gluteal → Trendelenburg gait
- LCNT → meralgia paraesthetica
🔌 Femoral Nerve
Roots: L2–L4
Motor: Anterior thigh → knee extension, hip flexion
Sensory: Anterior + medial thigh, medial leg and foot
Injury: Hip fracture, pelvic trauma
🔌 Obturator Nerve
Roots: L2–L4
Motor: Thigh adduction
Sensory: Medial thigh
Injury: Anterior hip dislocation
🔌 Sciatic Nerve
Roots: L4–S3
Motor: Posterior thigh (knee flexion), all leg and foot muscles
Sensory: Posterior thigh, lateral leg, entire foot
Injury: Posterior hip dislocation, acetabular fracture
🔌 Superior Gluteal Nerve
Roots: L4–S1
Motor: Gluteus medius + minimus → hip abduction
Sensory: None
Injury: Pelvic surgery or fracture
Sign: Positive Trendelenburg (pelvic drop on swing side when standing on affected leg)
🔌 Inferior Gluteal Nerve
Roots: L5–S2
Motor: Gluteus maximus → hip extension
Sensory: None
Injury: Pelvic trauma/surgery
🔌 Lateral Cutaneous Nerve of the Thigh (LCNT)
Roots: L2–L3
Motor: None
Sensory: Anterolateral + lateral thigh
Injury: Compression at ASIS → meralgia paraesthetica
Clinical Features: Burning/tingling thigh pain, no motor loss
🔌 Common Peroneal Nerve
Roots: L4–S2
Motor: Dorsiflexion + eversion (anterior + lateral compartments)
Sensory: Dorsum of foot, lateral leg
Injury: Fibular neck compression → foot drop
Features: High-stepping gait
🔌 Tibial Nerve
Roots: L4–S3
Motor: Plantarflexion + inversion
Sensory: Sole of foot
Injury: Posterior knee dislocation, popliteal trauma
📝 Exam Clues & Clinchers
- Foot drop = common peroneal nerve
- Pelvic drop on walking = superior gluteal nerve
- Meralgia paraesthetica = LCNT, sensory only
- Posterior hip dislocation → sciatic nerve injury
- Trendelenburg gait → gluteus medius/minimus (L4–S1)