Muscles pull on the joints, allowing us to move. They also help the body do such things as chewing food and then moving it through the digestive system. Even when we sit perfectly still, muscles throughout the body are constantly moving.
Muscles ca only contract and they also move your joints so this statement is true and false depending on your article or the info given to you but usually your body never fully stops moving. So if by motion you mean running/walking this statement is false but your eyes also have muscles so you might be perfectly still but you are still using muscles in you body. I would say this statement is false.
