The largest muscle is the buttock muscle (gluteus maximus), which moves the thighbone away from the body and straightens out the hip joint. It is also one of the stronger muscles in the body. The smallest muscle is the stapedius, in the middle ear.
It is thinner than a thread and 0.05 inches (0.127 centimeters) in length. It activates the stirrup that sends vibrations from the eardrum to the inner ear. The longest muscle is the sartorius, which runs from the waist to the knee. Its purpose is to flex the hip and knee.