I'm having problems when training legs. Doing hacksquats or regular squats on the machine or free weight I get aches and pains right above the top of my knee caps. I stretch and run before I do all exercises especially legs. The aches are only when im at the gym. I'm 20 yrs old and played high school basketball Ive had a few knee to knee bangs during that time but nothing serious.
do only real squats (no machine) get your ass out farther and to the floor. start light until you get used to it.