Chin-ups using gymnastic rings or related gadgets are easier on the elbows and shoulders while allowing you to supinate your hands throughout the pull, making for a huge contraction in your upper back.

To up the ante, try "fly away" ring chins. Pull yourself up normally, making sure to pull all the way to your sternum, but flare your elbows out to the sides and pull them back on the eccentric (negative), almost as if you're doing a front double biceps pose and trying to pull the rings apart.

Related:  10 Challenging New Ways to Chin-up and Row

Related:  Why You Need to be Doing Ring Pull-Ups