The theory is that the<unk>  nerve becomes irritated and/or inflamed from friction caused by compression by muscles in the forearm. Some speculate that<unk>  is a type of repetitive strain injury (RSI), but there is no detectable pathophysiology and even the existence of this disorder is questioned. The term<unk> " is used for compression of the posterior interosseous nerve, a division of the<unk>  nerve, at the lateral intermuscular septum of arm, while "supinator syndrome" is used for compression at the arcade of Frohse. The<unk><unk> " is the region from the humeroradial joint past the proximal origin of the supinator muscle. Some scientists believe the<unk><unk>  extends as far as the distal border of the supinator. The<unk>  nerve is commonly compressed within a 5 cm region near the elbow, but it can be compressed anywhere along the forearm if the syndrome is caused by injury (e.g. a fracture that puts pressure on the<unk>  nerve). The<unk>  nerve provides sensation to the skin of posterior arm, posterior and lateral forearm and wrist, and the joints of the elbow, wrist and hand. The nerve also provides sensory branches that travel to the periosteum of the lateral epicondyle, the anterior radiohumeral joint, and the annular ligament. It provides motor function through innervation to most extensor muscles of the posterior arm and forearm. Therefore, it is extremely important in upper body extremity movement and can cause significant pain to patients presenting with<unk> . Unlike carpal<unk>  syndrome,<unk>  does not present tingling or numbness, since the posterior interosseous nerve mainly affects motor function. This problem is often caused by: bone tumors, injury (specifically fractures of the forearm), noncancerous fatty tumors (lipomas), and inflammation of surrounding tissue.
Radial tunnel syndrome
Carpal tunnel syndrome
Ulnar tunnel syndrome
Tarsal tunnel syndrome
Calpainopathy
Anterior interosseous syndrome
Heel pad syndrome
Failed back syndrome