Yesterday was my back day ,well I started of with my dead lifts went threw my warm up sets,then my heavy sets and on my last set {which is usually medheavy or a hair lighter},and last rep I locked out and felt a uncomfortable feeling under my left rib cage,it doesnt hurt unless I do anything that consists of me contracting my core,like dead lifts,squats ,breathing in deep etc.,I've talked to a few people and they seem to think I pulled my acustic muscle{I have no idea how to spell it},I need to know what you all think and what I need to know about recuperating and do you all think it might be a good idea to treat it with some type of AAS such as test,deca or hgh,any comments would be greatly appreciated!