Radial Neuropathy

Injury sites

The radial nerve can be compressed within the axilla: all of its components are affected here; this commonly occurs from the use of crutches, which compress the nerve.
Where it wraps around the humerus in the mid-shaft is the spiral groove, an important radial nerve compression site, so called "Saturday night palsy" because it classically develops from hanging an arm on the back of a bar-chair and compressing the nerve (but being unaware of the arm paresthesias because of drunkenness).

The key way to distinguish these compression sites is that in radial nerve compression within the axilla, the triceps is weak; whereas in spiral groove compression, it is strong because triceps innervation lies proximal to the spiral groove.

The radial nerve can be compressed when it passes through the supinator muscle in the proximal forearm.

Weakness