Bones attach to each other by joints. Joints allow them to move and pivot around each other in different ways and directions. Bones attach to muscles by a firm, white thing called the tendon. If you cut your tendon in your foot, it would be very difficult to move your foot. The tendon allows movement in the body because muscles are what make bones move, and muscles move bones by pulling on the tendon. Bones move around different bones because the joint is there.