A patient is diagnosed with disc prolapse. Examination reveals paralysis of extensor hallus longus. Which nerve root is affected? (E. REPEAT 2010)
Ref: Apley s System of Orthopaedics and Fractures, 9th edition Explanation: Root values Muscles Lower limb action L1-L2 Iliopsoas Hip flexion L3 Quadriceps Knee extension L4 Tibialis Anterior Ankle dorsiflexion L5 Extensor Hatlucis Longus Extensor Digitorum Longus Great toe and lesser toes dorsiflexion Gluteus medius Gluteus minimus Hip abduction S 1 Flexor Hallucis Longus Flexor Digitorum Longus Toe plantar flexion Ankle plantar flexion Gaslrosoleus Gluteus maximus Hip extension S 2 Hamstrings Knee flexion Lumbosacral Radiculopathy--Neurologic Features Lumbosacral Nerve Roots Reflex Absent Sensory Motor Pain Distribution 1.2 -- * Upper anterior thigh * Psoas (hip flexion) * Anterior Thigh L3 -- * Lower anterior thigh Anterior knee * Psoas ship flexion) * Quadriceps (knee extension) - Thigh adduction * Anterior thigh knee L4 Quadriceps (Knee reflex) * Medial calf * Quadriceps (knee extension) Thigh adduction * Tibialis anterior (foot dorsiflexion) * Knee * Medial calf * Anterolateral thigh L5 -- * Dorsal surface--foot Lateral calf * Peroneii (foot eversion) * Tibialis anterior (foot dorsiflexion) * Gluteus medius (hip abduction) Toe dorsiflexors * Lateral calf * Dorsal foot * Posterolateral thigh * Buttocks SI Gastrocnemius Soleus (Ankle reflex) * Plantar surface--foot * Lateral aspect--foot * Gastrocnemius/soleus (foot plantar flexion) * Abductor hallucis (toe flexors) * Gluteus maximus (hip extension) * Bottom foot * Posterior calf * Posterior Thigh * Buttocks NEUROLOGIC EXAMINATION Deep Tendon Reflexes 1,4 Nerve Root (1,3-4 disc): Patellar Reflex or Knee jerk. SI Nerve Root (L5-S1 disc): Achilles Reflex or Ankle jerk. Motor Exam L4 Nerve Root (L3-4 disc): Ankle dorsiflexion. L5 Nerve Root (L4-5 disc): Great toe dorsiflexion (extensor hallucis longus). SI Nerve Root (L5-S1 disc): Ankle plantar flexion (gastrocnemius-soleus complex). Sensory Exam L4 Nerve Root (L3-4 disc): Medial malleolus. L5 Nerve Root (1,4-5 disc): Dorsal third metatarsophalangeal joint. SI Nerve Root (L5-S1 disc): Lateral heel.
L3
L4
L5
SI