Dermatomes look simpler when a person assumes a quadruped position.

Seeing how the dermatomes overlap on the skin shows us sensory overlap… BUT there is more overlap for touch than for pain!

So when testing for spinal nerve damage at a certain level…ALWAYS test for pain (pinprick etc).

Areas for specific segment testing:

1. posterior aspect of the shoulders (C4)

2. lateral aspect of the upper arms (C5)

3. medial aspect of the lower arms (T1)

4. tip of the thumb (C6)

5. tip of the middle finger (C7)

6. tip of the pinky finger (C8)

7. thorax, nipple level (T5)

8. thorax, umbilical level (T10)

9. upper part of the upper leg (L2)

10. lower-medial part of the upper leg (L3)

11. medial lower leg (L4)

12. lateral lower leg (L5)

13. sole of foot (S1)