I'm not deep into the technology. I apply one every 48 hours, though the directions say they only last for 24 hours. The keep me from being so stumbly. I've been using them for at least 3 years. It is subtle, but I wear one most of the time. I'm 85 years old. they help me enough that I will continue to buy them even if the company service is awful.
I tested myself and I can still trot even if I can't run.
They claim they let you try for 30 days, but I wouldn't count on them honoring that. If you buy from Amazon,I bet they would. I've had several other people try them and continue to use them. Amazon is $20 cheaper and doesn't charge a huge amount to ship it like the Super Patch Company does because they are located in Canada.
I apply one to my upper thigh. You want to put it where you w ll not be constantly hitting it while pulling your pants up over it. I take a sharpie and put the date and time I applied it so I know when to change it.
I didn't have a doctor recommend it. I can't remember where I learned about it. They also make socks but I don't like them as well as the patches.