I originally discovered Pain Pod about four ago from reviewing it for my travel website. I was so impressed by the science, and the results from happy users, that when I encountered a problem myself, a threatened recurrence of tennis elbow a few years ago, I bought a Pain Pod 3, used it and it fended off a full blown attack. I have since used it in earnest again twice, on my knees, initially to help heal a MCL strain in the left knee last year, and more recently a LCL strain in the right one. I find the treatments not only relaxing but effective and I wouldn't be without it now.