Hello @deborahinmaine, Welcome to Connect. That's a good question, I haven't seen anything about physical therapy as a treatment for PMR but do know from my own experience with PMR that exercise is beneficial as long as you don't over do it. Here's a reference I found that speaks to your question.

"Physical Therapy Management
There is currently no evidence for the use of physical therapy in the treatment of patients with PMR. However, it is still important to be aware that patients may still be referred to you with a primary diagnosis of PMR, or with PMR as a co-morbidity. Physical therapy can be incorporated as a valuable component of a therapeutic regiment for this patient group in order to reduce the risk of early functional impairment and severe disability.[20] A combination of exercise therapy and education is recommended in the treatment of PMR."
-- Polymyalgia Rheumatica:
https://www.physio-pedia.com/Polymyalgia_Rheumatica
Are you also on prednisone to treat the PMR?