THIS IS THE BEST KNEE STRAP I HAVE TRIED FOR CHRONIC PATELLAR TENDONITIS. I'M A LONG DISTANCE RUNNER AND THIS REALLY DOES THE TRICK. MY ONLY ADVICE IS THAT YOU SHOULD ERR ON THE SIDE OF THE NEXT LARGER SIZE IF YOU ARE CLOSE TO IT ON THE MEASUREMENT CHART. THEY WILL STRETCH OUT OVER TIME, BUT I'M NOT SURE HOW MUCH.