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).

Brachial_Plexus

Fig 1.

emd_16_021_07_02_med_0

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

The myotomes are as follows:

emd_16_021_07_03_med

Fig 3. Shoulder joint – C4-5 Abduction

emd_16_021_07_04_med

Fig 4. Shoulder joint – C7 Abduction

emd_16_021_07_05_med

Fig 5. Elbow joint – C5-6 Flexion

emd_16_021_07_06_med

Fig 6. Elbow joint – C7-8 Extension

emd_16_021_07_07_med

Fig 7. Elbow joint – C6 Pronation/supination

emd_16_021_07_08_med

Fig 8.Wrist joint – C6-7 Flexion

Fig. 9 Wrist joint – C6-7 Extension

Fig. 10 Fingers – T1 Abduction/adduction