According to the CDC, arthritis is the most common disability among adults in the USA. And even though multiple studies show that exercise is the best way to decrease pain and increase range of motion - one third of the people in the United States with arthritis don't exercise.
I have arthritis in my right shoulder and at times in my life, I've been part of that one third. I have adapted my program so I'm able to workout without my pain getting worse. Now I have less pain and more range of motion because I workout on a regular basis.