Recently my daughter, a high school teacher, asked me to make 150 or so textured stack rings to give to her graduating students, which I have done for years with no problems. However, repetitive motions can cause problems, which happened this year. After securing a wire length in a miter jig and vise, I will tightly hold it in my hand and/or brace it on the work surface. Then the filing begins. After 15 rings, I noticed that the inside of my wrist and going up my arm a few inches was starting to hurt, which had never happened before. After a few hand stretches, I kept going for a few more rings but had to stop because the pain continued and I knew it could possibly morph into lasting damage. It was time to stop and re-evaluate how I had always done things.