Cranial nerve XI
- Shrugs shoulder (trapezius)
C5
- Raises elbow to level of shoulder (deltoid)
C6
C7
- Extends forearm (triceps)
C8
T1
L2
L3-4
- Extends knee (quadriceps)
- Knee jerk reflex
L4-L5 & S1
L5 (most common disc herniation)
- Dorsiflexes big toe (EHL)
- Sensation in medial dorsum of foot and first webspace
S1 (2nd most common disc herniation)
- Plantar flexes ankle (gastrocnemicus)
- Sensation lateral foot
- Ankle jerk reflex