Intuition and common sense work well if based on reality, but can be very dangerous guides if based on fantasy.

Your whole arm MAY be partly at fault - the fingers/hand/arm is a complex mechanism - the mucles that move the fingers do so by means of long tendons well away from the point of movement - it is a good idea to see someone competent. Another guitarist, especially one who has suffered similar problems may be able to look at you and see something that will help you.

Posture is something to think about - many musicians develop problems which can be alleviated by a good consultant Physiotherapist.

An Australian Singer around the early 1900's developed a method which is much in vogue for dancers and singers and musos involving postural concepts - my dysnomia won't remember the name at the moment... some Physios are now incorporating that knowledge.

The body is a complex mechanism that causes engineer types some distress - so many parts of the body depend on others - robots isolate the movement of each part - which is why frozen shoulders (I have had both go on me) can be started by a muscular spasm in the back, and they won't go away or heal till the key muscle that started it is dealt with. That one muscle goes into spasm, and the muscles near it try to take the load, until the whole shoulder locks up and you pass out when it is bumped...

Also I note that there is a currently active thread by a harpist on Ulnar Nerve Compression for those with a scholarly interest.

Noted your comments there, Ebbie. So you seem to be on the right path...

Robin