I think I've finally figured out why my squat never increases. I decided to do single legged leg presses to go easy on my lower back and made a weird discovery. I'm right handed/legged (soccer) and my right leg is stronger/more flexible (I think). Anyway, when I do the press, my body is 30* to floor, weight is 45* to floor, so it's like a 105* angle. I put one leg on the press and the other one I push my heel to my ass. When I go down with my left leg, I can go all the way and it's just tough. When i use my right leg, I can onyl go about halfway and then my entire thigh just feels like it can't go any farther. If i use both legs I can go down all the way. For some reason, in that position my right leg will only go halfway and I'm assuming I'm losing tons of strength at the bottom of double legged lifts/presses because of this. Any advice on what could be causing this?