Wow...there isn't much you can do for the hug, is there? It's not like a voluntary muscle like an arm or leg that you can stretch out...the only thing I could suggest is gentle stretching of the upper back muscles to see if that releases some of the tightness feeding into the Intercostal area & diaphragm.

Try rolling into a ball and rocking gently... Stretching out the large muscles of the back. Then stretch out on your back and reach to the left without lifting your back off of the surface & hold for a few seconds. Repeat to the right.

Hope you can get relief soon...are you on zanaflex or baclofen?