The wrist remains partially flexed due to an opposing action of flexor muscles of the forearm.

Also, the brachioradialis, anconeus, triceps brachii and extensor carpi radialis longus are all innervated by muscular branches of the radial nerve in the arm.

Other screening tests include the inability to extend the thumb into a "hitchhiker's sign".

Initial treatment includes splinting of the wrist for support, along with osteopathic medicine, physiotherapy and occupational therapy.

In some cases, surgical removal of bone spurs or other anatomical defects that may be impinging on the nerve might be warranted.