From what I am seeing regarding internal injuries, as in my case a possible stretching of the iliopsoas (SP?), scar tissue possibly developed. When that happens, the muscle or connective tissue in question does not work like it did before the incident. In my case, I suffer bloating, possibly because the intestines associated with the injured muscle have trouble doing what they are supposed to do. Sorry for the layman's language, but that is the avenue I am exploring, after many doctors told me nothing could be done or they don't know. I hope this may help you.