Yeah, it seems there is a small percentage of the population that just gets elbow pain using a thumbless grip on the squat (me included). My squat form was cleared during a SS seminar and yet the pain persisted, hence why I changed to thumbs around. Regarding the long term effects of this on the wrist, I have found the following:
- When I started, it felt like my thumbs would fall off from pain. I started to use wrist wraps to counter this, which alleviated the problem a lot but not totally;
- After a few weeks, my wrists adapted and I now feel nothing (when using wraps; have not tried to squat without them in a while);
- Wrist strength, mobility, pain, etc. seems now to be at baseline levels. So no issues.
Why this happens to some people, I do not know, but there you go. Keep at it. And buy the wraps, seriously, they help a lot.