It takes a lot to bruise me. Never from spanking. Others bruise rather easy. Bacall does not bruise from spanking, but from hitting inanimate objects in her path.
Bruises are commonly caused by a blunt trauma or blow to the surface of the body. The impact causes a rupture in the small fragile blood vessels – called capillaries – which are just under the surface of the skin, though the skin itself does not break.
Blood from the damaged capillaries leaks underneath the surface of the skin and becomes trapped (in the interstitial tissues) because it cannot escape through the unbroken skin. This small pool of blood is what causes the distinctive red, purple, blue or black discolouring known as a bruise. The blue or black appearance gave rise to the saying “black and blue” following an injury.
The blood vessels usually repair themselves quickly but there is little that can be done to avoid bruising once an injury has occurred. However, to limit the degree of bruising you can try to minimize the amount of blood that leaks from the rupture by a) sitting down, b) applying pressure or holding ice on the area for 10 – 15 minutes.
So if you bruise someone, just tell them to sit on it.