The muscles of the hand are innervated by the radial, median, and ulnar nerves from the brachial plexus.

The extensors are located on the back of the forearm and are connected in a more complex way than the flexors to the dorsum of the fingers.

The tendons unite with the interosseous and lumbrical muscles to form the extensorhood mechanism.

The thumb has two extensors in the forearm; the tendons of these form the anatomical snuff box.

The median nerve innervates the flexors of the wrist and digits, the abductors and opponens of the thumb, the first and second lumbricals.