My lower back has been hurting a few hours after i do the deadlifts. For me, it feels very awkward doing deadlift in these non round plates, but my college only has these. Also, I think my lower back is too weak. My squat at its best was 230 1x5, but deadlifts was 225 1x5(back hurt after =[ ). I think i should try to lower the weight and reset at around 155 ? Any help would be appreciated.