Squats?

[Douglas]

Squat once per week.

Go ass to the ground. Your hamstrings should touch your calves at the bottom. This will put the least amount of stress on your knees, believe it or not.

Dude, I've tried this before with just the bar and it hurt my knees! Perhaps it may have something to do with me being naturally stiff, but I wouldn't suggest going down like this doing squats, powercleans, or anything else.