Past two months I've had back pain,while lifting specifically stuff from the floor(but its more than manageable, but can tell the difference when its not there). Its only bad when I am inactive, like if I sit in class or lay down for a while, and when I go to get up its fucking crippling. Once I get moving though the pain is still there but greatly diminishes. Its in the lower back and when I go from like a flexion in my spine to an extension it hurts, also I noticed while trying to stretch that if I am laying on my back and bring knees up to were my body almost looks like an L(without an extended knee) then try to extend my knee I am unable to and it causes pain.
Sounds like a disc related issue so have you seen a doctor? The pain is only localized to your back but causes pain when you raise your leg?