I have one rotary cutter, my first, that is not shaped properly and I do hurt when I use it. Before I found out and bought the non slide material for the back of the ruler I pressed too hard and brought the beginnings of arthritis to my left forefinger-followed by pain and weakness. so It is important to pay attention to hurts, stop, rest, use the right rotary cutter and keep it at the proper angle with the forefinger on the resting spot.
I went thru 2 1/2 months of PT this summer for my neck and shoulder, then legs. PT helps to build the muscle around the hurt area, it does not cure.....the dems electrodes and applied heat relax the muscles so they can be worked with and strengthened....my neck is 75% improved and I have to exercise every morning, and watch my posture in everything I do...even using the computer can bring on the problems. So, know how to avoid the hurt, strengthen the muscles so they carry the weight. It takes retraining, with hopes that one can relearn to stand, walk and sit straight.