Hi, thanks for using healthcare magic The fact that the pain that you are experiencing occurred after you were moving some boxes and painting would imply that it is more than likely related to either the muscles or bones that would have been involved in your activity. The repeated movements could affected the muscles, tendon, ligaments and bones involved. In addition it is possible that the chest pain is related to costochondritis. This is inflammation of the area where the ribs meet the sternum. It can be associated with moderate to severe chest pain, which is constant and can feel worse on movement of the torso or pressing the sternum. You may want to consider the use of an anti inflammatory pain killer such as ibuprofen, diclofenac, aspirin, celebrex. These should be used on a full stomach. Rest of the muscles or bones involved would also be important. I hope this helps