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Choose a Page:What is the skin for?How do muscles work?How many bones do we have?What is inside a bone?What are veins and arteries?How does the heart work?*How do our joints work?* How do our joints work? Joints are the places where bones move against each other. Shoulders and hips have ball-and-socket joints. These allow movement in any direction. Elbows have hinge joints, which allow them to move backward and forward. A pivot joint allows the head to turn sideways.   Previous: Back Book: Best Ever Q&A Section: Science & Technology Chapter: Human Body