Note. This is not a complete list, but summarises some of the most clinically relevant nerves which might be encountered in the MSRA. 

Femoral nerve

  • Nerve roots - L2-L4
  • Motor function - Muscles in the anterior thigh - knee extension and thigh flexion
  • Sensory function - Anterior + medial thigh, medial leg and foot
  • Injuries - Hip fracture or stab wound

Obturator nerve

  • Nerve roots - L2-L4
  • Motor function - Thigh aDduction
  • Sensory function - Medial thigh
  • Injuries - Anterior hip dislocation

Sciatic nerve

  • Nerve roots - L4-S3
  • Motor function - Posterior compartment of thigh - knee flexion + all muscles of leg and foot
  • Sensory function - Posterior thigh, lateral side of leg and sole and dorsum of foot
  • Injuries - Hip dislocation, acetabular fracture

Superior gluteal nerve

  • Nerve roots - L4-S1
  • Motor function - Gluteus medius and minimus - hip aBduction
  • Sensory function - nil
  • Injuries - Pelvic fracture or surgery
  • Signs - Positive trendelenburg sign - when standing on the affected leg/during walking the pelvis drops on the contralateral/swing side

Inferior gluteal nerve

  • Nerve roots - L5-S2
  • Motor function - Gluteus maximus - hip extension/lateral rotation 
  • Sensory function - nil

Lateral cutaneous nerve of the thigh (LCNT)

  • Nerve roots - L2-L3
  • Motor function - Nil
  • Sensory function - Anterolateral and lateral thigh
  • Injuries - Meralgia paraesthetica: compression of LCNT at the ASIS causes pain, tingling and numbness in the distribution of the LCNT 

Common peroneal nerve

  • Nerve roots - L4-S2
  • Motor function - Eversion and dorsiflexion of the foot, extensor hallucis longus
    • Injury presents with FOOT DROP
  • Sensory function - dorsum of foot, lateral leg
  • Injuries - trauma, knee dislocations, external compression at fibular head 

Tibial nerve

  • Nerve roots - L4-S3
  • Motor function - Plantarflexion and inversion of the foot
  • Sensory function - Sole of the foot
  • Injuries - Posterior knee dislocation, popliteal laceration