This is how muscle knots function. Those in one muscle might spread to the rest of the muscles and create discomfort. The main issue is that not all pain can be seen on an x-ray or an MRI. That doesn't imply there aren't any issues that need to be addressed or diagnosed. Pain management focuses on treating the source of your pain, rather than just masking it with medications. The best way to know if you have muscle knots is by feeling them. Your doctor may want to do this during a physical exam. If you're worried about them causing problems, then seeing a doctor is the best course of action. In conclusion, an MRI cannot show muscle knots but they can cause pain and limit your range of motion if not treated. Seeing a doctor is the best course of action if you're worried about them or if you experience pain when moving your muscles.