The term "metacarpophalangeal" refers to the joints in the hand where the metacarpal bones meet the phalanges, or finger bones. These joints are crucial for hand movement, allowing for bending and straightening of the fingers. Each finger has one metacarpophalangeal joint, while the thumb has a similar joint that enables its unique range of motion. Metacarpophalangeal joints are classified as synovial joints, which means they are surrounded by a fluid-filled capsule that reduces friction during movement. They play a vital role in various hand functions, including gripping, pinching, and manipulating objects.