Hey Meg ... The only way I get my lower quads developed is from leg extensions, but with my current knee problems I can't handle the weight I need so I have been thinking about adding a squat/leg ext superset.

Sissy squats would be a good one too, but they are an uncomfortable exercise.

I'll poke around and see what I can find from "the boys" ... My legs don't take much work to grow, but I'm sure I can talk to one of me BB buddies who have trouble with legs and see what they do.