My right arm was normal with no decreased
flexibility. There was no pain, and I just figured the problem with the left arm was reduced
flexibility due to aging.
Then about 4-5 months ago, I noticed that the range of motion had reduced even more. Maybe a few more inches. Still no real pain. This basically only affected the ability to reach behind my back and wash it in the shower. Up until that time, it never entered my mind that something could be wrong with my shoulder/upper arm.