why doesn't a cast saw hurt the skin underneath the cast but you might think the doctor is just extra careful during this process but the answer actually lies within the saw you see this saw doesn't spin it actually vibrates and these vibrations are able to cut through hard materials like the plaster in a cast but when it comes to softer more elastic materials like skin the small teeth of the blade can't get a grip while it's vibrating instead it sort of just pushes the skin back and forth
