so far so Good! I just received my Patt straps two days ago. Before I got them I could run about twenty five minutes and then my knee would start to ache (IT band). The first time I used the Patt strap I got to twenty five minutes and there was no aching; however I could feel my knee. The second time I used it I wrapped it very tight and and I got to 41 minutes with no aching!!!!! Thank you Patt strap!