Spinal cord levels

Motor Exam (Myotomes)

Sensory dermatome by spinal level.
Spinal cord tracts
Lower limb peripheral innervation
  • C3-C5: Diaphragm
  • C5: Shoulder Abduction
  • C5-C6: Elbow Flexion
  • C6-C7: Wrist Extension
  • C7-C8: Elbow Extension
  • C8: Finger Flexion
  • T1-T6: Intercostal Muscles
  • L3-L4: Thigh Adduction
  • L2-L4: Knee Extension
  • L4-L5: Ankle Dorsiflexion
  • L5-S1: Great Toe Extension
  • S1-S2: Ankle Plantarflexion
  • S2-S4: Anal Sphincter Contraction


C7 triceps
L3 quadriceps
S1 achilles tendon
S2,3,4 bulbocavernosus, anal wink

Sensory Exam

  • C2 Occiput
  • C3 Thyroid Cartilage
  • C4 Suprasternal Notch
  • C5 Below Clavicle
  • C6 Thumb
  • C7 Index Finger
  • C8 Little Finger
  • T4 Nipple Line
  • T10 Umbilicus
  • L1 Femoral Pulse
  • L2-L3 Medial Aspect of Thigh
  • L4 Knee
  • L5 Lateral Aspect of Calf
  • S1 Lateral Aspect of Foot
  • S2-S4 Perineal Region

Cervical Exam by Level

Radiculopathy Motor Deficit Sensory Deficit Diminished Reflex
C4 Levator Scapulae & Shoulder elevation
C5 Deltoid & Biceps Biceps
C6 Brachioradialis & Wrist extension Thumb Paresthesia Brachioradialis
C7 Triceps & Wrist flexion Index/Middle/Ring Paresthesia Triceps
C8 Index/Middle distal phlnx flexion Small Finger Paresthesia

See Also