RESPONSE TO COMMENTS on PL | JACK NICKLAUS JR. - 201709 | 03. Left Arm Rotation // Here Dan from Raleigh, North Carolina asks whether the arm rotates or the forearm flips. Great question, Dan. This is a question that a lot of people ask and one that confuses the golf industry in general. The arm rotates in the shoulder socket. However, this can only happen if your shoulders are relaxed. If you tighten your shoulders, you force your forearms to flip, and that√ïs what causes trouble in your game.