Hinge Joints
The simplest type of joint is the "hinge," as found in the elbows and
the joints of the fingers and toes. Hinge joints allow movement in only
one direction. The hinge joint of the knee, the body's largest joint, is
unusual because it can swivel on its axis, allowing the foot to turn from
side to side. Thus, the knee is constantly rolling and gliding during
walking.