<s>[INST] Three days ago my cousin picked me up from behind to pop my back. He weighs about 250 pounds and I weigh 120 pounds. My back popped loudly in several places. Now The middle of my back feels very bruised and the pain radiates down to my upper buttocks. I mainly feel this pain when I stretch my back or when I'm sitting down. I am an active 29 year old female. Please help! [/INST] Oops...Popping could go dangerous if not down in a proper way. Pain radiation might be due to disc. Thrust could cause the spine to go hyper-extension which can put the impact on disc.  Well, apply ice to the low back area and run down the ice to the buttock too. Sleep on the side or lay down in the floor with the legs resting on a chair. Apply ice for 15-20mins for 2-3 days. You would feel better.Cheers.. </s>