Stopped squatting for a while and just stuck with leg press, curls, and extensions but starting to see huge lack in size. my back and knees had always been achy because of squats so I have recently starting using this free motion squat machine at the gym. You can not put on too much weight on the machine but it seems to work everything well but my lower back which i need. just wondered if any of you guys have used this before and could tell me how effective this machine really is.