For those that don't know, I am a yellow belt in Karate, and currently working to learn more, usually 3 days a week. I study at a Fred Villari's studio in Trevose. The chief instructor is Jim Wing, there he teaches me Shaolin Kempo Karate.
I am in an advanced training class where I get to go to as many group classes as I can get to, and I get one semi-private lesson a week. Last night, I suffered some bruised ribs as Jim explained the finer points of showing no mercy to someone who attempted to stab you. In this case I was the simulated stabber... Ouch
However, there appears to be no permanent damage, and I derived considerable utility learning more about the nuances of footwork and lines of sight.
Additionally I now know for sure if someone tries to stab me and I get him on the ground and stomp on his ribs, he will be displeased