On swing sets

It may sound funny, but almost every morning, except when it's raining, you can find out early around the local park and swing sets. That's because my right shoulder started hurting early this year. At first I thought it would just go away, but finally it didn't so I did enough research to make me learn I probably have a torn rotator cuff, which I thought I couldn't get because I don't lift weights. I may have gotten it doing regular pushups or Hindu pushups. However, it's most likely from sleeping on my side, especially because what I slept on at my mother's house was a pull out bed that folded out from a small sofa. I had no idea you could get a torn rotator cuff just from sleeping on your side.