What is the anatomically correct name for the 'knuckle' joint?

What is the anatomically correct name for the 'knuckle' joint?

• A. Metacarpophalangeal joint
• B. Interphalangeal joint
• C. Radiocarpal joint
• D. Carpometacarpal joint

Answer: (A)

The knuckle joint is where the metacarpal bones meet the proximal phalanges, called the metacarpophalangeal joint. It’s a condyloid joint that allows flexion, extension, abduction, adduction, and some circumduction, which is what enables gripping and pinching. The other joints mentioned aren’t knuckles: interphalangeal joints lie between phalanges themselves, the radiocarpal joint is the wrist between the radius and carpal bones, and the carpometacarpal joints are between the carpal bones and the metacarpals (the base of the thumb being a special saddle joint).

The knuckle joint is where the metacarpal bones meet the proximal phalanges, called the metacarpophalangeal joint. It’s a condyloid joint that allows flexion, extension, abduction, adduction, and some circumduction, which is what enables gripping and pinching. The other joints mentioned aren’t knuckles: interphalangeal joints lie between phalanges themselves, the radiocarpal joint is the wrist between the radius and carpal bones, and the carpometacarpal joints are between the carpal bones and the metacarpals (the base of the thumb being a special saddle joint).