How do bones and skeletal muscles work together to produce movement?

Bones and skeletal muscles work together as a mechanical system to produce movement through a lever-based process. Because muscles can only contract, they require a rigid structure—the skeleton—to act as an anchor and a system of joints to facilitate motion.12

The interaction functions through the following mechanisms:

• Attachment: Skeletal muscles are attached to bones via tendons, which are strong, fibrous connective tissues that transmit the mechanical force of muscle contraction directly to the bone.34
• Leverage at Joints: Muscles span across joints, which serve as the pivot points for movement. When a muscle contracts, it pulls on the bone at its insertion point, causing the skeletal element to rotate or move around the joint.1
• Antagonistic Pairs: Since muscles can only pull, they typically work in antagonistic pairs. For example, one muscle (the agonist) contracts to move a bone in one direction, while its partner (the antagonist) relaxes; to reverse the movement, the roles are switched. A classic example is the biceps and triceps in the human arm, which bend and straighten the limb, respectively.251

This coordinated system is regulated by the nervous system, which manages the force, speed, and precision of these contractions.41