The interosseous muscles: the foundation of hand function.

The interosseous muscles of the hand can be thought of as the cornerstone of hand function, as they provide a "foundation" for all intrinsic and extrinsic hand movements. Innervated by the ulnar nerve and organized in dorsal and palmar layers, these pivotal muscles have small excursion yet great impact on finger balance, grip, and pinch function, particularly when impaired by denervation and/or contracture. This article gives an overview of the functional anatomy and pathologic dysfunction of the interosseous muscles within the context of this Hand Clinics issue on the intrinsic muscular function of the hand.