I'll try to make this as short as possible -- over the past 6 months, I've developed multiple pain issues while bowling. Wrist, hand, forearm and elbow.
For a long time, I subconsciously knuckled the ball. When I was younger, I got away with it. I'm no longer getting away with it.
The main problem is that I cannot get a good feel in the ball. My thumb alternatively sticks and slips inside the thumbhole. Using smaller-size holes only makes the sticking worse, while using larger holes plus tape only makes the slipping worse.
Currently, cut-to-cut, my middle finger span is 4 1/8 and my ring span is 4 1/4. My thumbhole is pitched 1/8 reverse and 1/8 away, and these numbers haven't changed in 20 years. Although I drill my own stuff, I recently enlisted the help of a veteran driller to measure me and give me his opinion on how he'd fit me, and he says my current pitches appear, on the surface, to be correct.
But the pain I'm feeling says otherwise. Most of it is concentrated on the palm side of my wrist, on the top side of my wrist directly behind my pinky finger, and in the forearm muscle just below the elbow joint. When I squeeze something, it all hurts worse.
I've tried different kinds of tapes, I've put Magic Carpet in thumb holes, I've tried different ovaling and beveling. I've tried about a half-dozen wrist braces, and bowling with no brace. No relief. Now it's getting worse instead of better.
Recently, the problem grew into a quality-of-life problem. I had to sleep in an elbow-immobilizing brace every night because, for about two months, I had a major flare-up of tennis elbow (I don't play tennis) aggravated by bowling.
The only thing I can think of left to try is different pitching in the thumb hole. I want to have a very relaxed grip. The predominant feeling I get when I bowl now is that I'm having to grip the ball for all it's worth. But if I add tape to the thumbhole, it starts hanging up almost instantly.
What I need to know is by how much to shorten the span if I were to go from, say, 1/8 reverse to 1/4 or 3/8 forward. I plan to take the lateral back to 0. I've bowled with under lateral before, and it hurt like hell, so I think that's probably out. I'm also for taking other suggestions as to what might be the problem, but I'll warn you ahead of time, I've probably already tried everything else you can think of already.
Well, I didn't keep it short after all. Sorry.