Honestly, I was out at a site near Sedona last month and another geologist straight up told me my swing looked off. He said, 'You're holding it like a regular hammer, you're gonna wreck your wrist.' Tbh, I switched to a lighter Estwing with a better grip and it made a huge difference after just a few trips. Has anyone else had to totally change their basic tool technique?
Professor Miller at my old school always said a good grip is about control, not force. I see where @the_thea is coming from, but a comfortable hold that works for you is what really matters in the field. Isn't the goal just to keep the rock from flying out of your hand?