radial nerve palsy causes
Radial nerve palsy. Radial nerve palsy in the arm most commonly is caused by fracture of the humerus, especially in the middle third (Holstein-Lewis fracture) or at the junction of the middle and distal thirds. The nerve may be compressed by the lateral intermuscular septum.
Other, less common causes of radial nerve palsy in the arm include compression at the fibrous arch of the lateral head of the triceps and compression by an accessory subscapularis-teres-latissimus muscle.