I suffer from the patellar tendinitis, also known Jumper`s Knee. A false step while jogging and my knee was inflamed painful for a week. Actually I bought the knee belt with little hope and was very surprised that it works. With the Velcro you can adjust the distance well and the incorporated tubes holds the kneecap from below "in position". And it slips nothing! Since then I wear the knee belt, I can run at a stretch without problems one hour. If that is not a success!