Here is an old but great website that explains all the trigger points in every muscle…it also shows where the pain may be referring too. A little gem. Look up the chart to find where your pain is, and you will see a few muscles that may be the cause. You will then find out where the trigger points will be in these muscles, and even a few stretches you can do. Use your imagination and get on the tennis ball in these areas, once you hit the trigger point, your pain should replicate. Hang onto it until it goes away.