I`m nearly 49 years old and am having more or less chronic knucle pain issues in my left hand, and also chronic inflammation issue in my right arm. I double on drums and DB, and can confirm that all of this is DB- and physical work related. I exercise and stretch reqularly and enjoy a planetary diet, which in my case means mostly vegan food. I`m average size guy with a big bass, and I have tried basically all string and setup options. My trial for solution on these issues is going to be a second bass, a small modern 3/4 or 5/8 bass with a bit shorter than standard string lenght. I will propably keep my big bass, but will set it up with extra light tension strings like gut / Evah slap mix. The small bass will serve a arco / all around / travel bass duty with some sort of contemporary string setup. So, I`m looking for a solution from a instrument that is as easy to play as possible, along with trying to learn a economical and healthy technique.
I wish that you find a solution that will keep you playing with joy and peace of mind, along with a healthy body.