The collateral ligament of interphalangeal articulations of hand are fibrous bands located on each side of the fingers' interphalangeal joints. These are hinge joints. They allow the fingers to bend and extend. There are two sets of collateral ligament of interphalangeal articulations of hand. One set is for the proximal interphalangeal joints. The other set is for the distal interphalangeal joints. In each finger, there are three bones known as phalanges. The bone at the tip of the finger is described as “distal.” The second bone is described as “intermediate.” The bone closest to the palm is described as “proximal.” The proximal interphalangeal joints are located between the proximal and intermediate phalanges. The distal interphalangeal joints are located between the distal and intermediate phalanges. The proximal and distal interphalangeal joint articulations are anatomically similar. The biggest difference is that the distal joint has less mobility. The joint cannot bend further than 20 degrees. There are also minor differences. For example, they differ in the segmentation of their flexor tendon sheaths.