I am just wondering if this is something that is usual with ms. I have been having a muscle spasm under my right rib daily for several months. Once the spasm radiated to the center of my sternum, but other than that is always under my right rib. I can even feel the muscle contracting, it feels like a potatoe under my rib cage. It than relaxes after a few seconds and the pain goes away. I did not know what this was for quite awile and than finally figured out it is a muscle spasm. I am not diagnosed with ms, but am trying to put the pieces of the puzzle together to determine what my symptoms are caused by.