Nick Nilsson on Instagram: "Open Hand Pull-Ups... this pull-up variation is going to really challenge your finger and hand strength. The wide open hand position forces you to clamp down onto the top of the ball with your fingers in a disadvantageous position. If you've never done open hand grip work, this will be an eye-opener for you. To set this up, you'll need a few pieces of equipment. I'm using a 50 lb slam ball (a medicine ball or wall ball of similar size will probably work) and a dip bel