I'm a high school senior whose football season has recently ended. I've been going to the local YMCA to work out on my own (I have no plans for playing in college, I'm just working out because I enjoy it). I'm happy where I am, and with the progress I'm making- I don't want to body build, I just want to get stronger. However, I'm a little worried about my squat form. During football offseason the past three years, the coach has had us do a 10-8-6-4-2 pyramid, increasing the weight each time. Doing this, my squat for 2 reps is at about 275.
My problem is that whenever I get up into the higher reps, I feel like I'm putting a lot of pressure on my spine and my lower back. My lower back always hurts, especially after a lower body day. Am I damaging my spine, or is it normal to feel that back pain and pressure during a squat? Also, this may be just a myth, but can squatting heavy weight for low reps like that stunt your growth? I would really appreciate anyone who can tell me whether or not I'm doing something wrong. Yes, I do go deep on the squat, and I have been squatting like this for three years under a coach's supervision so I am pretty sure my form is good.