You only need to wash your comforter once or twice a year, unless it gets dirtied before then. The duvet cover needs washing more often, about once a week. If you use a top sheet regularly, though, you can probably wait two to four weeks between washes for the duvet cover.
Four-legged animals also have these muscles and use them for pushing forward when running.
The gluteus maximus is the largest muscle found on the human body. This is a large and powerful muscle that keeps the trunk of the body in an erect posture. This muscle is also the reason why we can easily climb up the stairs. The human buttocks have three main muscles.