Researchers in France have recently used computer models to understand why knuckles make popping noises when cracked, identifying the cause as a collapsing cavitation bubble in the synovial fluid of the metacarpophalangeal joint. Brant is confused on the timing of their study though. Apparently he has personally known of the synovial fluid in the metacarpophalangeal joint for years now, and feels the need for better communication within the scientific community to avoid duplicating efforts. He’s just sayin.’