Radial nerve can be compressed at any site and by various etiologies during its anatomical course. Compression or injury to the nerve can cause denervation of the extensor or supinator muscles and numbness or paresthesia in the distribution area of the radial sensory nerve. Common clinical symptoms include pain, muscle weakness or dysfunction.

Entrapment of the radial nerve mostly occurs at 3 anatomical regions: proximal to the elbow, at the level of posterior interosseous nerve, distal forearm or wrist. Vast majority of the cases are presented with the entrapment of the posterior interosseous branch of radial nerve in the proximal forearm where the nerve passes through the fibers of supinator muscle. Differential diagnosis of two discrete conditions that are referred as posterior interosseous syndrome and radial tunnel syndrome is essential and rather based on clinical findings. Radial tunnel syndrome can be diagnosed based on clinical criteria those primarily include clinical symptoms; and it is, in principle, a diagnosis of exclusion. Treatment of radial nerve entrapment can be conservative or surgical depending on the etiology itself.