Ligament · Hand

Palmar plates of the fingers

A thick pad of fibrocartilage forming the floor of every finger joint — the palm-side wall of the capsule at each knuckle and each joint beyond it. It is anchored firmly to the base of the bone in front of it and only loosely to the neck of the bone behind, so when the finger straightens the plate folds and slides back out of the way instead of tearing, and when the finger bends it glides forward again. It is the structure that stops a finger from bending backwards, and it doubles as a floor the flexor tendons run over: the first, third and fifth pulleys of the tendon sheath arise straight from the plates rather than from bone. Turn the hand over and it is the plates, not the bones, that your finger joints are resting on.