I tried 5x10 hanging pikes today as a part of ABBH, and I couldn't do 10 except maybe on the first set. But my abs weren't the limiting factor, my shoulders were! I felt like my shoulder joints were going to dislocate from the strain at the top of the rep.
I think I'm doing them wrong, but I've done them as described...I lift my knees up, tilt back til shins touch the bar, and then lower slowly. How can I take the strain off my shoulders? If I'm doing them right, how can I work my way up to doing more?