Myotomal Innervation
From pEx
Myotome - the muscles served by a single nerve root. It is the motor equivalent of a dermatome.
- C1/C2 - Neck flexion/extension
- C3 - Neck lateral flexion
- C4 - Shoulder elevation
- C5 - Shoulder abduction
- C6 - Elbow flexion/wrist extension
- C7 - Elbow extension/wrist flexion
- C8 - Thumb extension
- T1 - Finger abduction
- L2 - Hip flexion
- L3 - Knee extension
- L4 - Ankle dorsi-flexion
- L5 - Great toe extension
- S1 - Ankle plantar-flexion
- S2 - Knee flexion
Myotomal Innervation of the Upper Limb
- Brachial plexus - derived from C5-8 and T1, with variable C4 and T2
- Form 3 trunks, splitting into anterior and posterior divisions which form 3 cords, which then form 5 branches:
- Musculocutaneous, axillary, radial, median and ulnar nerves
