Dr Carter will fix you up.
But from a layman's point of view - correct:-
Stance.
Grip.
Hand spacing.
Hand position
Arm position
Technique
Are all very important, as you paddle further and get older (me) you will avoid injury if you get the above things correct. Perhaps get some professional coaching on a one on one basis to correct any issues you have.
Take it easy and get well.
ET.