Little finger
The little finger is the fifth and smallest digit of the human hand, positioned on the ulnar edge opposite the thumb.
Phalanges: The small bones forming the fingers and toes, arranged in proximal, middle, and distal segments. The little finger has three phalanges, the basic bones that give it length and joints.
Hypothenar eminence: The muscular mound along the ulnar side of the palm at the base of the little finger. Its muscles move the little finger and shape the palm’s outer edge.
Ulnar nerve entrapment: Compression of the ulnar nerve, commonly at the elbow or wrist, causing sensory or motor symptoms. Numbness in the little finger is a characteristic clue to ulnar nerve involvement.
Thumb: The first digit of the hand, specialized for opposition and a wide range of grasping movements. Unlike the little finger, the thumb sits across the palm and enables opposition.
Metacarpal bones: Five long bones form the framework of the palm, each connecting to a finger. The fifth metacarpal connects the little finger to the wrist-side of the palm.
Abductor digiti minimi: A hand muscle that moves the little finger away from the ring finger. It spreads the little finger, widening the hand’s grasp.
Fifth metacarpal fracture: A break in the metacarpal bone connecting the wrist to the little finger. This common hand fracture can alter the little finger’s alignment and knuckle contour.
Ring finger: The fourth digit of the hand, between the middle and little fingers. The ring finger lies immediately beside the little finger and is typically longer.
Metacarpophalangeal joint: A joint connecting a metacarpal bone to the proximal phalanx of a finger. This knuckle joins the little finger to its metacarpal and permits flexion and spreading.
Opponens digiti minimi: A hand muscle that draws the fifth metacarpal forward and rotates it toward the thumb. It helps cup the palm and bring the little finger toward the thumb.