I keep getting a pain in the lower right hand side of my back, near the lip of my pelvis whenever I squat? Only happens once I get to around 100-120kg. Ive had ACL reconstructions on both knees, and due to have a osteotomy and 2nd stage ACL revision again on my left knee this summer, hence why the weight im pushing is pish. I thought it would be my knees giving me bother but they seem ok, when ive pushed higher weights since injury my left knee tracks in slightly but I can correct it. I can feel the pain still in my back as im pulling the plates off the bar. Once I move on to the Leg press, the pain is still there for the 1st couple of sets, but then disappears after. And im pushing 230-250kg on Leg press. Any ideas?