Abductor digiti minimi muscle of the hand

Muscle of the hand

The abductor digiti minimi muscle of the hand is a muscle located in the hypothenar eminence of the hand. It plays a crucial role in the movement of the little finger, specifically in its abduction.

Structure

Abductor digiti minimi muscle of the hand

The abductor digiti minimi muscle originates from the pisiform bone, which is one of the carpal bones of the wrist. It also has attachments to the pisohamate ligament and the tendon of the flexor carpi ulnaris. From its origin, the muscle fibers extend distally to insert into the base of the proximal phalanx of the little finger and the extensor expansion of the finger.

Function

The primary function of the abductor digiti minimi is to abduct the little finger away from the hand's midline. This action is important for the spreading of the fingers, which is necessary for grasping and manipulating objects. Additionally, the muscle assists in flexing the proximal phalanx of the little finger at the metacarpophalangeal joint.

Innervation

The abductor digiti minimi is innervated by the ulnar nerve, specifically by its deep branch. This nerve provides the necessary motor signals for the muscle to contract and perform its functions.

Blood Supply

The blood supply to the abductor digiti minimi muscle is primarily provided by the ulnar artery, which supplies oxygenated blood to the muscle tissue, ensuring its proper function and health.

Clinical Significance

Carpal tunnel anatomy

Injury or compression of the ulnar nerve can lead to weakness or paralysis of the abductor digiti minimi muscle, affecting the ability to abduct the little finger. This can occur in conditions such as cubital tunnel syndrome or ulnar nerve entrapment.

Anatomical Relations

The abductor digiti minimi is part of the hypothenar muscles, which also include the flexor digiti minimi brevis and the opponens digiti minimi. These muscles work together to control the movements of the little finger.

Surgical Considerations

Dissection of the hand showing the abductor digiti minimi

During surgical procedures involving the hand, care must be taken to preserve the integrity of the ulnar nerve and the blood supply to the abductor digiti minimi to prevent postoperative complications such as muscle weakness or atrophy.

Development

The abductor digiti minimi muscle develops from the mesodermal layer of the embryo, along with other muscles of the hand. Its development is influenced by genetic and environmental factors during fetal growth.

Related Pages

• Hypothenar eminence
• Ulnar nerve
• Flexor carpi ulnaris
• Cubital tunnel syndrome

Anatomy of the hand