Superior trunk of brachial plexus

Looks like

The top trunk of the brachial plexus, formed by the C5 and C6 roots, above the collarbone.

What it does

Carries fibres for the shoulder muscles, biceps and skin of the outer arm and thumb side.

Keeping it well

Stretched when the head and shoulder are forced apart (birth, motorbike falls): Erb palsy with the arm hanging turned inward.

Its parts

• Anterior division of superior trunk of brachial plexus
• Posterior division of superior trunk of brachial plexus

Related conditions

• Amyloidosis (AL and ATTR)
• Botulism
• Chickenpox (varicella)
• Chronic neuropathic pain
• Chronic pain syndrome
• Fibromyalgia
• Frozen shoulder (adhesive capsulitis)
• Guillain-Barré syndrome
• Lyme disease
• Myasthenia gravis
• Peripheral neuropathy
• Polymyalgia rheumatica
• Rabies
• Restless legs syndrome
• Shingles (herpes zoster)
• Shoulder dislocation
• Tetanus
• Thoracic outlet syndrome
• Vitamin B1, C and other deficiencies