Sharp Tailbone - Knee Tuck Crunches and Other Moves

Does anyone else notice discomfort/pain in the tailbone when doing certain moves, e.g. knee tuck crunches? I also notice this on get up toe touches.

Edited to add: I already use a pretty thick mat, but still feel the discomfort; it feels like my tailbone is poking into the ground.

Any thoughts on how to handle or alternate moves? Thanks!

Edited