Palmar interosseus

Palmar Interossei are a group of three small, unipennate muscles in the hand that are located on the metacarpal bones. They are part of the intrinsic muscles of the hand, which are responsible for its fine movements. The palmar interossei muscles are situated on the medial side of the metacarpal bones and are responsible for adduction of the fingers towards the middle finger.

Anatomy

The palmar interossei muscles originate from the metacarpal bones and insert into the base of the proximal phalanx and the extensor expansion of the corresponding finger. Each muscle is innervated by the deep branch of the ulnar nerve.

Function

The primary function of the palmar interossei muscles is to adduct the fingers towards the middle finger. This is an important function in gripping and manipulating objects. In addition to adduction, these muscles also assist in flexion of the metacarpophalangeal joints and extension of the interphalangeal joints.

Clinical Significance

Damage to the ulnar nerve can lead to a loss of function of the palmar interossei muscles, resulting in a condition known as claw hand. This condition is characterized by an inability to flex the metacarpophalangeal joints and extend the interphalangeal joints, leading to a claw-like appearance of the hand.

See Also

• Dorsal interossei of the hand
• Intrinsic muscles of the hand
• Metacarpal bones
• Ulnar nerve