The proximal interphalangeal (PIP) joint is a hinge joint located in the fingers and toes. It connects the proximal phalanx, which is the first bone of the finger or toe, to the middle phalanx, the second bone. This joint allows for bending and straightening movements, playing a crucial role in hand and foot function. In the human hand, each finger has a PIP joint, while the toes also have corresponding PIP joints. The PIP joint is important for grasping and manipulating objects, contributing to activities such as writing and typing. Proper function of the PIP joint is essential for overall dexterity and mobility.