for the past few days i've noticed a tension in my right hand when i play. its not painful or anything its just tightens up and is incredibly annoying. its in the space between the knuckles of my 2nd and third fingers (middle and ring). i recently started squeezing those gripmaster things in case that has anything to do with it and also i've started keeping my fingers closer to the fretboard which is also a possibility, any tips regarding tension relief (in any part of the body, lol i fear i'm just begging for a few dick jokes with that comment ) would be a big help
I've had something similar happen, it happened after I stopped playing for a week. I exercised with those grip things and kinda stretched out and massaged the area. Went away after a few days, might solve your problem.