Getting My cast To Work

If a part of your body is inside of a cast, it's got a plaster cast all around it to guard it whilst a broken bone repairs alone:

: a mass of plastic make a difference formed in cavities of diseased organs (given that the kidneys) and discharged from the human body

discard indicates the letting go or throwing away go here of a thing that has become ineffective or superfluous while often not intrinsically valueless.