I would also recommend Hypervolt from Hyperice. It is very quiet compared to other brands and I can use it while watching TV or listening to music. I also had shoulder pains, and it limited my mobility while doing training at gym. I have much better mobility and pain is almost gone from using Hypervolt. It helps tremendously with muscle tension and soreness after workout. I use it daily after workout and sometimes during workout when I get a muscle cramp. My muscle is refreshed next day without tensions and it helps with preventing injury and keeps me going. I liked it so much, I got another one to gift to my gym buddy, and he and his wife use it daily as well. I wouldn’t pay over $100 for modified jigsaw.