Palmar interossei muscles

Palmar Interossei Muscles

The Palmar Interossei Muscles are a group of three small muscles located in the hand. They are part of the intrinsic muscles of the hand, which are responsible for fine motor functions. The Palmar Interossei Muscles are situated on the palmar (front) side of the hand, between the metacarpal bones.

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Illustration of the Palmar Interossei Muscles

Anatomy

The Palmar Interossei Muscles originate from the sides of the metacarpal bones and insert into the bases of the proximal phalanges and the extensor expansion. They are unipennate, meaning they have fibers on one side of the tendon only. 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. They also assist in flexion of the fingers at the metacarpophalangeal joints and extension at the interphalangeal joints.

Clinical Significance

Damage to the Palmar Interossei Muscles can result in a loss of finger adduction and can affect the ability to grasp objects. This can be tested clinically using the Froment's sign.

See Also

• Hand anatomy
• Intrinsic muscles of the hand
• Metacarpophalangeal joint
• Interphalangeal joints