What kind of test can show my diaphragm motion(doc suspects it is very contracted and unable to fully relax)because i have general muscle rigidity?

Diaphragm: chest xray with inpiration and expiration. Xray with lungs fully inflated- inhale deeply, and x ray with lungs deflated- fully exhaled

Testing: I would recommend discussing an ultrasound, pulmonary function testing in the upright and supine positions, with your physician. If you are being evaluated for a myopathy, they can also test chest wall muscular strength in the pulmonary lab.