What role do muscles play in the body?

Muscles play a crucial role in the body primarily by facilitating movement through their ability to contract. The correct answer highlights that muscles pull and push on bones, which is essential for all forms of movement, including walking, running, and even simple actions like waving a hand. This interaction between muscles and bones is made possible through tendons that connect muscles to bones, allowing for a coordinated mechanical system. When a muscle contracts, it exerts a force on the attached bone, resulting in movement around a joint. This role is fundamental to locomotion and daily activities, making it a vital function of the muscular system in conjunction with the skeletal system.