My father was in Fire Restoration which is heavy and very hard work, especially on the joints and knees. Requires a great deal of painful scrubbing, use of the hands, bending, kneeling, lifting, carrying, etc. You name it...not easy for a woman. Also studied Arnis...something did it but who the Hell knows?
I'm only 35 so I hope it's nothing more than hard work but even when I hold the gun in my left hand and squeeze -- I feel it. I tried racking the gun previously and hurt myself the whole time. What I was actually trying to do was to rack it and lock it in place so I could load it. After a while I gave up and went back to using my left hand. Wish there were some way to master this motion with the right hand too.