To muscles to extended flex or to contact and relax when moving Bones don't work alone — they need help from the muscles and joints. Muscles pull on the joints, allowing us to move. They also help the body perform other functions so we can grow and remain strong, such as chewing food and then moving it through the digestive system.The skeleton is the body's framework. It is made of bones, which provide a firm surface for muscles to attach to, so that they can move. Without a skeleton, we would not be able to move at all. The skeleton also supports the body and protects our internal organs.