Question

why do fingers crack?

Answer 1

When you “crack” your knuckles, or any other joint, it expands the space between your bones, creating negative pressure that draws synovial fluid into the new gap. This influx of synovial fluid is what causes the popping sound and feeling when you crack a knuckle.

Answer 2

Cracking finger joints (knuckles)—crackingjoints is the act of pulling bones apart to release air bubbles in the joints. The sound of a knuckle being cracked (pictured: common knuckle joints) happens when joint manipulation in humans produce a sharp cracking or popping sound.