All of my suggested remedies have already been listed.... Advil, not gripping so tightly, bent shaft, stretching, etc. I have only had mild bouts with elbow problems from kayaking, so I'm far from an expert.
BUT... I once got what my buddies called "Rocker's Elbow" after the Robert Plant/Jimmy Page reunion concert in New Orleans back in college. ('93 ish) Anyone suffering from this should try ice, advil, and beer. haha
"I'm putting a personal bounty on the head of Tim McCrackin. He's the coach, and chief punk on that Syracuse team. A hundred bucks of my own money to the first of my boys who really nails that creep!" --Coach Reg Dunlop, Charlestown Chiefs