Motor Exam


Motor Exam, Strength Grading, Muscle Strength, Myotomes, Motor Nerve, Motor Root, Motor Neurons, Motor Strength, Rapid Extremity Motor Exam

  • Types
  1. Upper Motor Neuron Lesion (everything is UP - tone, reflexes, toes)
    1. Muscle group weakness (not complete paralysis) and minimal Muscle atrophy
    2. Increased Muscle tone ("Clasp-knife" spasticity)
    3. Hyperreflexia with or without Clonus
    4. Babinski Reflex positive response
  2. Lower Motor Neuron Lesion (everything is DOWN - tone, reflexes, toes)
    1. Flaccid Paralysis
    2. Muscular atrophy
    3. Muscle fasciculations and fibrillations
    4. Hyporeflexia
    5. Absent Babinski Reflex
  • Exam
  • Muscle Strength Grading
  1. Grade 0: Total Paralysis
  2. Grade 1: Palpable or visible contraction
  3. Grade 2: Full range of motion with gravity eliminated
  4. Grade 3: Full range of motion against gravity
  5. Grade 4: Full range of motion with decreased strength
  6. Grade 5: Normal Strength
  7. NT: Not testable
  • Exam
  • Rapid Extremity Motor Exam (Common Extremity Motor deficits)
  1. Upper extremity
    1. Radial Nerve (C5-C6, C7-C8): Wrist Drop
      1. Dorsiflexion wrist, fingers against resistance (extensor carpi radialis, extensor digitorum)
    2. Median Nerve (C7, C8, T1): Cannot make 'OK' Sign
      1. Opposition of thumb and index finger against resistance
    3. Ulnar Nerve (C8-T1): Claw Hand
      1. Finger abduction against resistance
  2. Lower extremity
    1. Femoral Nerve (L1-L4)
      1. Hip flexion against resistance (Iliopsoas Muscle)
    2. Sciatic Nerve (L5-S2)
      1. Knee flexion against resistance (Hamstring Muscles)
    3. Deep Peroneal Nerve (L4-L5): Foot drop
      1. Dorsiflexion against resistance (tibialis anterior Muscle)
    4. Tibial Nerve (S1-S2)
      1. Plantar flexion against resistance (gastrocnemius Muscle, soleus Muscle)
  • Exam
  • Upper Extremity Strength
  1. brachialPlexus.jpg
  2. C3-5: Spontaneous Breathing ("C3-4-5 keeps the diaphragm alive")
  3. C3-4: Trapezius function
  4. C5: Shoulder External Rotation (Infraspinatus)
  5. C5: Deltoid and Supraspinatus abduction at Shoulder (Axillary Nerve)
  6. C5-6: Biceps Flexion at Forearm (Musculocutaneous Nerve)
  7. C6: Forearm Supination (Radial Nerve)
  8. C6-7: Forearm Pronation (Pronator Teres; Median Nerve)
  9. C6-7: Wrist Extension (extensor carpi radialis brevis and longus; Radial Nerve)
  10. C7: Wrist Flexion (flexor carpi radialis brevis and flexor carpi ulnaris; Median Nerve and Ulnar Nerve)
  11. C7: Elbow Extension (Triceps, Radial Nerve)
  12. C7-8: Finger Extension (Extensor digitorum, extensor indicis, extensor digiti minimi; Radial Nerve - posterior interosseous)
  13. C7-8: Thumb Abduction (Abductor Pollicis Longus; Radial Nerve - posterior interosseous)
  14. C8: Thumb Extension and Adduction
  15. C8: Wrist Extension and incline ulnar aspect of hand (Extensor Carpi Ulnaris)
  16. C8: Fingers Flexion middle finger (flex dig profundus, Median Nerve)
  17. C8-T1: Thumb Flexion (flexor pollicis longus, Median Nerve - anterior interosseous)
  18. T1: Small finger abductors (abductor digiti minimi)
  19. T1: Spread Fingers (Interosseus intrinsic Hand Muscles; Ulnar Nerve)
  • Exam
  • Lower Extremity Strength
  1. L2-3: Hip flexors (Iliopsoas)
  2. L3-4: Knee Extension (Quadriceps)
  3. L4: Ankle dorsiflexion (tibialis anterior)
  4. L4: Anterior Tibial - Foot Inversion
  5. L5: Great toe extension (Extensor hallucis longus)
  6. L5: Foot dorsiflexion (Extensor digitorum longus)
  7. L5: Weak heel walking, foot drop
  8. S1: Ankle plantar flexors (Gastrocnemius, Soleus)
  9. S1: Toe walking
  10. S1: Foot Eversion
  11. S2-4: Reflex Defecation Center ("S2-3-4 keeps the stool off the floor")