I saw an ad a while back (like recently, May 2018?) for a device that supports your hand when doing barre chords. Since then my advanced age and more playing have given my thumb some trouble. Does anyone know what that device was/is. Even better: has anyone tried it?
Thanks!
I tried using a thumb brace similar to this, as I have arthritis in both thumbs. Problem is, any pressure against the joint is going to hurt. I’ve learned to adjust my grip to the extent possible to lessen the pain, and the eventual increase in the muscle at the base of the thumb has helped some. Mostly, I just try to avoid playing songs that require barre chords. Good luck.
Maybe lighter strings?
Lighter strings and a lower action. Plus, learn to only apply the slight pressure that is required to barre the chord. For many years, I used a death grip on barre chords. However, now that my hands are getting older (not me of course 
) I have learned that it requires far less pressure than I used to apply. I still revert to a death grip when playing my old punk repertoire but it is possible to play them with lighter pressure.