I landed hard on my butt during a motorcycle crash in 1984, and during a bicycle crash 2 years ago. The bruises were less painful and healed a lot quicker when I was 25 instead of 50. I was not able to lay down to sleep or able to sit for 3 weeks after the last crash, because I bruised my tailbone and pulled tendons in my back and belly- there was no way to lay down or sit that did not hurt, even with Vicodin. I paced back and forth all night, and took little naps until the pain made me get up again.
The armored underwear looks like a much more useful item, if you ever crash without it like me and wish you had it on.