To stabilize the right hand, many bassoonists use an adjustable comma-shaped apparatus called a "crutch", or a hand rest, which mounts to the boot joint. The crutch is secured with a thumb screw, which also allows the distance that it protrudes from the bassoon to be adjusted. Players rest the curve of the right hand where the thumb joins the palm against the crutch. The crutch also keeps the right hand from tiring and enables the player to keep the finger pads flat on the finger holes and keys.