Lumify X9 This is important. Not all knee braces are created the unique way and what you would need to look into is which kind of hinges include the proposition 19. Why? Well, the reason why you will be wearing the knee brace is which will help protect your knee, and it could usually be worn by being moving. If you attempt to flex and extend your knee while walking and running, then you will not want to experience low quality hinges that won't glide in your movement. Plain and simple. Polycentric hinges are quality hinges that can move with you, considering how that your knee wishes to Tactical Pen bend and straighten.