In the human hand, palmar or volar plates (or ligaments) are in between the hand bones called metacarpals in the palm, and the finger bones called phalanges.

Palmar plate
Finger joint straightening and bending, palmar plate in grey
Anatomical terminology

These plates or ligaments help protect and control the finger bones, make sure they move the right way, and make sure the finger joints can't be pulled apart.

Structure change

This joint padding starts at the bottom joint of the first finger bone (proximal phalange), and then goes on to the next joint connecting to the middle finger bone (intermediate phalange).

Additional images change