Brachial Plexus

The upper limb is supplied from the C4 to T1 nerve roots. Occasionally T2 is also involved (Fig 1).

The dermatomes of the upper body are as shown, and each of the roots can readily be assessed (Fig 2).

Fig 1.

Fig 2. Upper body dermatomes (courtesy of Gecko Graphics)

The myotomes are as follows:

Fig 3. Shoulder joint C4-5 Abduction

Fig 4. Shoulder joint C7 Abduction

Fig 5. Elbow joint C5-6 Flexion

Fig 6. Elbow joint C7-8 Extension

Fig 7. Elbow joint C6 Pronation/supination

Fig 8.Wrist joint C6-7 Flexion

Fig. 9 Wrist joint C6-7 Extension

Fig. 10 Fingers T1 Abduction/adduction