Finally, I decided to post a question here, which bothers me very much - maybe somebody with a good understanding in anatomy and exercise can answer. I like doing ab wheel roll-outs (only from the knees or standing isometric, though). Reading about shoulder position in various exercises and related safety, I feel that the ab wheel actually might not be good for shoulders - a close grip, palms forward. Also, arms cannot freely rotate in the shoulder joint and that possibly can lead to wearing out and pain (which I have a bit). Do you think, is it really an issue?