The abductor digiti minimi is a muscle in the hand that abducts the little finger (digiti minimi). It's one of the hypothenar muscles, located on the ulnar (pinky) side of the palm.
Anatomy of the Abductor Digiti Minimi
Here's a breakdown of its key anatomical features:
- Location: Hand (Hypothenar eminence)
- Origin: Pisiform bone and tendon of the flexor carpi ulnaris.
- Insertion: Base of the proximal phalanx of the little finger (digiti minimi).
- Action: Abducts the little finger at the metacarpophalangeal joint (moves it away from the middle finger). It also assists in flexing the little finger at this joint.
- Innervation: Ulnar nerve (deep branch)
- Blood Supply: Ulnar artery
Function
The primary function of the abductor digiti minimi is to abduct the little finger. This action is crucial for gripping objects and performing fine motor movements. It also contributes to the overall shape and contour of the hypothenar eminence (the fleshy prominence on the ulnar side of the palm).
Clinical Significance
- Ulnar Nerve Entrapment: Damage or compression of the ulnar nerve, such as in cubital tunnel syndrome, can weaken or paralyze the abductor digiti minimi, leading to difficulty abducting the little finger. This can manifest as weakness in grip strength and clumsiness.
- Hypothenar Hammer Syndrome: This condition involves damage to the ulnar artery in the wrist, potentially affecting blood supply to the abductor digiti minimi and other hypothenar muscles.
- Muscle Strains/Tears: Although less common, the abductor digiti minimi can be strained or torn due to overuse or trauma.
Summary
In conclusion, the abductor digiti minimi is a vital muscle in the hand responsible for abducting the little finger, contributing to grip strength and fine motor skills. Its function can be compromised by ulnar nerve damage or other conditions affecting the hypothenar eminence.
