For actual active pain management, I’d probably lean towards the mini as the frequency is better suited to pain.
However, the big is a great way to have the body start to release the tensions and move towards a better state, and is really good at preventing the pain in the first place.
When I used the mini, I stacked the coils (with the bumps facing towards each other), for deeper penetration.
I know that doesn’t tell you which one per se, but if you have the time, let him try both for some 15m before he borrows one to find which helps him the best.
Blessings
Reviewed by Jeff Kaczor, 1 May 2021.