Myotomes

Myotome testing is conducted in order to determine muscle power and possible neurological weakness originating from the nerve roots in the cervical spine. Myotomes are tested by resisted isometric movements with the joint at or near the resting position. The patient is seated with the head in neutral as for isometric resistance testing. The following movements should be tested with their corresponding nerve root level:

  • Neck flexion: C1-C2
  • Neck side flexion: C3 and CN XI
  • Shoulder elevation: C4 and CN XI
  • Shoulder abduction/shoulder lateral rotation: C5
  • Elbow flexion and/or wrist extension: C6
  • Elbow extension and/or wrist flexion: C7
  • Thumb extension and/or ulnar deviation: C8
  • Abduction and/or adduction of hand intrinsics: T1

The examiner should tell the patient “Don’t let me move you” to obtain an isometric contraction. Note: the contraction should be held for at least 5 seconds so that weakness, if any, can be noted. Always test both sides for comparison (Magee 2007). 


Dermatomes
Reflexes
Examination