I've been an Amazon customer for many years now, but it's only just recently that I've been moved to write a review. This product is one of the reasons.
I was several months into my road running and was suddenly - and without warning - struck down with debilitating IT Band pain in my left knee. Fortunately a friend of mine is an Ironman competitor and had already spoken to me about the woes of ITBFS (Iliotibial Band Friction Syndrome) so I had an idea what it was. Lots of reading later and I had confirmed my ailment. There is lots of good info out there regarding the various possible causes and also the different ways in which it can be countered, through RICE (google "rice running"), stretches, strengthening exercises, massage therapy, running form etc. Make sure you seek out this info.
In combination with additional stretches, this compression strap really does work. It helps to stop pain whilst out on your run by stabilising the IT band above the knee. Incidentally, it can also be used below the knee to stabilise the patella, though I have no need for this.
The first time I used it, my IT band started throbbing about 10mins into the run. A quick adjustment - I moved it closer to the knee cap and tightened it - and the difference was remarkable. I finished the run without pain. The moral - Experiment with positioning before writing it off.
This WILL NOT cure your ITBFS, though it will enable you to continue to run while you seek out what your real issue is. It should also help to prevent a recurrence once you're on the mend.
I found it incredibly depressing when I had to take 8 days out to rest my knee. This strap (along with stretches and foam-rolling) has given me the confidence to get back out there pounding the pavements!
I've started getting a niggle in my right knee when running downhill... I've since ordered another two of these: One for my right knee and another to rotate them while they're being washed!
5 stars.