Spoon busk

The spoon busk was a specialised kind of busk—the rigid element of a corset placed at the centre front.

As its name implies, it was shaped like a spoon, with the bottom part of the busk widening and taking a dished form.

The spoon busk allowed a greater reduction in waist size without producing a bulge of flesh at the bottom edge of the corset.

This was a problem experienced when corsets with straight busks of even width were tightly laced: as the flesh of the abdomen was, essentially, squeezed out of place and appeared where there was no pressure.

The wide, dished part of a spoon busk accommodated the abdomen, and at the same time compressed and controlled it.

a modern busk from 1919, to compare
The pads E will prevent the lower ends of the steels A B from hurting the wearer when she sits down; from 1879.
Corset from 1873. The spoon busk is covered in fabric but shown shaded pink, for clarity.