<unk><unk>  nerve (C7-8) is a branch of the radial nerve that supplies motor innervation to the forearm extensor muscles
Compression or injury can cause an isolated PIN palsy 
More proximal pathologies can cause a combined palsy
More common in body builders and laborers due to repetitive pronosupination
Peripheral neuropathy
Repetitive microtrauma
Entrapment
Trauma
Forearm fracture
Space occupying lesions
Ganglion cyst
Lipoma
Bone tumor
Iatrogenic
Repetitive microtrauma
Entrapment
Trauma
Forearm fracture
Space occupying lesions
Ganglion cyst
Lipoma
Bone tumor
Forearm fracture
Ganglion cyst
Lipoma
Bone tumor
Posterior interosseous neuropathy
Carpal tunnel syndrome
Anterior interosseous neuropathy
Pronator teres syndrome
Ulnar neuropathy
Suprascapular neuropathy
Long thoracic neuropathy
Radial neuropathy at the spiral groove 