Both knees affected but only one compartment in each knee, but I need them for competitive play and or work or due to my body weight. (greater than 200 pounds) **If using on one side only then look to purchasing the comfort insoles to balance the resultant height of the opposite shoe.
The material on the wedged insoles is a poly urethane, molded into the intended wedge. It is a closed cell urethane so it will not absorb fluids; i.e. sweat. It is easily compressible with each step with excellent material memory to immediately return to the original shape. It will retain its shape and effectiveness up to one year with constant wear under customary use.