My knees click all the time, they've always clicked, and if there is any genetically-enhanced feature with my particular make and model, it's gotta be my knees -- I can't tell you how many mogul fields I've gone past the point of failure in over the years... or didn't see myself entering in the first place due to flat light conditions while I was doing my best "La Bomba" impersonation for the first run of the day (let's just say I was lucky my knees missed my head). Never had a complaint or pain about them. Never 'crunched' though, either. (I can promise any woman a kid with atomic blast shields for knee caps... and that's about it.)
Crunch = danger.