Replying to Lower left back pain

Okay, well for the past couple weeks I've been having this pain in my lower left back , almost in my hip region. It is most likely due to soccer and jumping in track, but I'd figure I'd ask people here anyways. It hurts if I jump off of my left leg or and suddenly, or sometimes even if i just walk. It doesn't really hurt to the point where i can't move, but its just really annoying and is kinda messing up my jumping and skiing too. Anybody have any ideas?