I can’t say sca108 if it’s PMR but that seems most likely to me. PMR can present symptoms that aren’t logical. For instance, about 90 days before I came down with all the typical PMR symptoms, I was experiencing pain in my shoulders after walking. Just my shoulders and it would go away within a half hour. Turns out it was an early warning symptom because a few months later those same shoulder muscles, along with the major muscles in my legs became almost unbearably painful and stiff. That was the beginning of PMR in my case. It’s a puzzling condition.