If you are looking for a replacement part or the "proper piece" of equipment for spinal decompression:
: You can generally double any note as long as it isn't a "tendency tone" (like the leading tone). inversion
: While not a physical part, the "proper" setting for full decompression is often cited as 60 degrees , where disc pressure reaches near zero. If you are looking for a replacement part
In music theory, the "proper piece" for a first inversion triad refers to the specific note that should be doubled to maintain balanced harmonies. inversion
: A wet spatula or dental floss is typically used to invert the dam.
: The proper note to double is the 3rd (the bass note) .