Digitus minimus

Digitus minimus of the human hand, commonly known as the little finger or pinky finger, is the most ulnar and smallest of the five digits of the hand. The term "digitus minimus" is Latin for "smallest finger". In medical contexts, it is referred to as the "fifth digit".

Anatomy

The digitus minimus is located on the ulnar side of the hand and consists of three phalanges: proximal, middle, and distal. Unlike the thumb, it has two interphalangeal joints (proximal and distal) and one metacarpophalangeal joint. The little finger contributes to the overall function of the hand, particularly in grip strength and dexterity.

Musculature

The primary muscles involved in the movement of the digitus minimus are:

• Flexor digiti minimi brevis – which flexes the metacarpophalangeal joint
• Abductor digiti minimi – which abducts the finger away from the hand
• Opponens digiti minimi – which rotates the fifth metacarpal bone to oppose the thumb

Nerve Supply

The nerve supply to the digitus minimus is primarily provided by the ulnar nerve. This nerve is responsible for both the sensory and motor supply, allowing for movement and sensation.

Blood Supply

The blood supply to the little finger is through branches of the ulnar artery.

Clinical Significance

The digitus minimus is often involved in medical conditions such as:

• Dupuytren's contracture – a condition that affects the connective tissue under the skin of the palm, causing the fingers to curl inward.
• Fractures of the phalanges – common injuries that can affect the function of the finger.
• Arthritis – particularly osteoarthritis and rheumatoid arthritis, which can cause pain and limit mobility.

Cultural and Social Aspects

The little finger often has social and cultural significance. For example, in many cultures, extending the pinky finger while drinking tea is seen as a sign of elegance. The pinky promise, where two people hook their pinkies together to signify a promise, is a common gesture in many parts of the world.

See Also

• Hand
• Finger
• Phalanx (bone)
• Metacarpus
• Ulnar nerve