99% of adults over 40 have shoulder "abnormalities" on an MRI, study finds (arstechnica.com)

I could have sworn that the same thing happened with back pain, in the past?

Ten, twelve years ago I couldn't lift my right arm over my head to reach for a mug on a shelf without pain. Sometimes so much pain I had to use my left arm instead. Today I can do single arm pull-ups without any pain. No MRI, not even a physio, just careful exercise. Started by regularly swimming, then weights, then calisthenics.