The muscles in our body are responsible for almost every bodily movement that we do, whether it be breathing, walking, climbing stairs, swallowing food or just blinking our eyes. Even small actions like turning your head to look at something require the use of muscles. Muscles allow us to move parts of our bodies by contracting and relaxing. Some examples of contraction might include raising your arm so you can wave someone over or squeezing your hand into a fist so sharply that it hurts because you hit something too hard.