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Inferior Lateral Cutaneous Nerve of the Arm

nervus cutaneus brachii lateralis inferior

The inferior lateral cutaneous nerve of the arm is a branch of the radial nerve arising in the spiral groove of the humerus, supplying sensory innervation to the lateral aspect of the lower half of the upper arm and the lateral elbow region. It is distinct from the superior lateral cutaneous nerve of the arm (a branch of the axillary nerve).

Region: Upper Arm

Clinical Relevance

Clinical Notes

The inferior lateral cutaneous nerve of the arm is used to map the level of radial nerve injury. Its preservation indicates the lesion is distal to the spiral groove, while its loss alongside posterior cutaneous nerve of the forearm confirms a spiral groove or more proximal injury. It is at risk during the posterior approach to the humerus for shaft fracture plating. Numbness in its distribution is a reliable localising sign of spiral groove pathology.

Pathology

Common Injuries & Conditions

Spiral Groove Radial Nerve Palsy

Combined loss of the inferior lateral cutaneous nerve of the arm and the posterior cutaneous nerve of the forearm, producing a sensory map that localises the radial nerve lesion to the spiral groove, associated with humeral shaft fractures and Saturday night palsy.