Muscle function refers to the ability of muscles to contract and produce movement in the body. Muscles work by shortening and pulling on bones, which allows for various actions such as walking, lifting, and even breathing. There are three main types of muscles: skeletal, smooth, and cardiac. Each type has a specific role in the body, with skeletal muscles being responsible for voluntary movements. The contraction of muscles is controlled by signals from the nervous system. When a muscle receives a signal, it activates its fibers, leading to contraction. This process requires energy, which is provided by adenosine triphosphate (ATP). Proper muscle function is essential for overall health and mobility.