Right now, you are looking at a foot! I bet you do a lot of walking during the day so you definitely appreciate how hard your feet work! In particular, the hinge joints....

Your toes use hinge joints (back-and-forth movements like hinges on a door). Elbows, knees and fingers also have these types of joints.

Hinge joints are classified as a movable joint. The other movable joints in your body are pivot, ball-and-socket and gliding joints.