Muscle function refers to the ability of muscles to contract and produce movement in the body. Muscles are made up of fibers that can shorten and lengthen, allowing for various types of movements, such as walking, lifting, and even breathing. There are three main types of muscles: skeletal muscle, which moves bones; smooth muscle, found in organs; and cardiac muscle, which makes up the heart. When a muscle contracts, it pulls on the attached bones, creating movement at the joints. This process is controlled by the nervous system, which sends signals to the muscles to initiate contraction. Proper muscle function is essential for overall health, enabling daily activities and maintaining posture.