• Examination of this nerve involves testing the skin along the posterior aspect of the arm for sensation.
• Provides sensation to the posterior aspect of the upper arm.
• Originates from roots C5, C6, C7, C8 and branches from the radial nerve.
Sensory examination includes testing the posterior aspect of the arm innervated by the posterior brachial cutaneous nerve.
• Ask patients to draw area of diminished sensation/numbness on a body diagram.
• Testing the skin along the posterior aspect of the arm for reduced/absent sensation by use of light touch (or other sensory examination modalities).
• Provides sensation to the posterior aspect of the arm.
Adjacent Sensory Distribution:
PROXIMAL – Superior lateral cutaneous.
MEDIAL/ANTERIOR – Medial brachial cutaneous nerve.
MEDIAL/POSTERIOR – Intercostobrachial and medial brachial cutaneous nerve.
DISTAL – Lateral antebrachial cutaneous nerve.
• Roots: C5, C6, C7, C8.
• Nerve: Radial nerve.
• Sensory Territory: Posterior aspect of the arm.
• Innervation Route: C5, C6, C7, C8 → radial nerve → posterior brachial cutaneous.
Course: The posterior brachial cutaneous nerve branches from the radial nerve just proximal to the posterior antebrachial cutaneous nerve (PABC) in the axilla and course through the arm in proximity of each other. After which, the nerve innervates the posterior aspect of the arm.
Inferior Lateral Cutaneous Nerve: The inferior lateral cutaneous nerve provides sensation laterally within the posterior brachial cutaneous sensory distribution. This nerve was found to branch from the posterior brachial cutaneous nerve.