make a video so we can judge your form
if olympic high bar squats feel better than by all means do it
I'm having trouble with the back squat. It often causes me lower back pain because my lower back rounds when I approach parallel (I verified this when I tried to squat down next to a mirror). On the other hand, front squats don't seem to give me any pain. I have tried different things and I can't seem to be able to maintain the arch. If I arch the lower and upper back hard, and try to flex the abs, then the lower back rounding isn't so apparent but the back definitely becomes looser and the pelvis tucks under. How do I fix this? Since the front squat doesn't give me any pain, do you think that I should try to change my back squat to a complete olympic style squat? By the way, I have been lifting for over a year (but I am not very strong...).
make a video so we can judge your form
if olympic high bar squats feel better than by all means do it
Sounds like your lower back is weak and you are unable to maintain (or incorrectly achieving to begin with) extension. Probably need some more data here.
Do you have a vid? Maybe some stat info as well (height/weight, lifts are at etc).