Dad has pmr controlled w/ 20mg prednisone. has bad back spams (feels lower back is being pulled). okay when walking but bad when gets up from sitting.rheum doesn't think d/t pmr.what could be cause?

Low back source: In general pmr affects the proximal muscles of the upper and lower extremities but not the trunk muscles. Your father may have degenerative disc disease which puts bone on bone or spinal stenosis which encroaches on nerve roots. Both can give muscle spasm and cause stiffness after being immobile. Regular exercise including stretching and strengthening of the core muscles should be done regularly.

Cannot diagnose: If your dad has polymyalgia rheumatica, is being seen regularly by a rheumatologist, and does not have a specific diagnosis, would you really accept a guess over the internet by someone who has never seen him. If you are not satisfied with his doctor, have him seen for a second opinion. Hope he feels better soon.