Referred to as either "Crutches" or "Handrests" these items are considered essential by many bassoonists and unnecessary impediments by others.
The function of the crutch is to assist in stabilizing the position of the bassoon. In general, players supporting their instruments with a neckstrap will find them necessary. The neckstrap provides little or no control of the rotation of the bassoon. The crutch provides this. Players using seatstraps find this less of a problem and often prefer not to use a crutch. For those players the use of a crutch is matter of individual preference.
Many players are mistaken in the belief that the function of the crutch is to fill up the space between the palm of their right hand and the boot joint of the bassoon. While that could be considered a minor function it is not the primary function, which is to control the position of the bassoon.
Within this catalog we will use the terms "crutch" or "handrest" to refer to the part that you actually contact while playing the instrument. A "crutch assembly" or "handrest assembly" includes both the crutch and the bracket. The term "bracket" refers to the metal unit screwed to the boot joint into which the crutch is inserted. The "stem" of the crutch is the metal piece that extends from the crutch and connects the crutch to the bracket.