Dermatome

Every muscle in the body is contracted by a nerve pathway traceable to a particular level of the spine. Disc herniations and spondylosis, the degenerative bone and cartilage condition, causes pressure on these nerves and cause them to feel pain, numbness or tingling. With the dermatome and the pain profile of patient one can informally indicate the source of the spinal problem, however a full electromyograph (EMG):

  • C3,4 and 5 contract the diaphragm, the muscles responsible for breathing.
  • C5 nerves also contract the shoulder muscles and the muscle we use to bend our elbow.
  • C6 bends the wrist back.
  • C7 straightens the elbow.
  • C8 bends the fingers.
  • T1 spreads the fingers.
  • T1 –T12 supplies the chest wall & abdominal muscles.
  • L2 bends the hip.
  • L3 straightens the knee.
  • L4 pulls the foot up.
  • L5 wiggles the toes.
  • S1 pulls the foot down.
  • S3, S4 and S5 supply the bladder. bowel and sex organs and the anal and other pelvic muscles.