Pronator quadratus has same innervation as following muscles-
Flexor pollicis longus
Flexor digitorum superficialis
Palmaris longus
Flexor carpi ulnaris
Pronator quadratus is supplied by anterior interosseous nerve which is a branch of median nerve. This anterior interosseous nerve supplies deep muscles of anterior forearm: Flexor pollicis longus Lateral half of Flexor digitorum profundus of index & middle fingers Pronator quadratus. Flexor digitorum superficialis supplied by median nerve Palmaris longus supplied by median nerve Flexor carpi ulnaris supplied by ulnar nerve
Muscles of arm and forearm region & Cubital fossa