A knee brace for treating hyperextension in a patient's knee. The knee brace includes two lateral uprights and a back support positioned horizontally to and generally at a middle portion of the lateral uprights. The lateral uprights and the back support define an integral frame. A plurality of straps includes a thigh, shin and patella strap connected at opposed ends to the frame for securing the brace to the patient. A plurality of cushion pads is disposed along inner surfaces of the lateral uprights and the thigh and shin straps for providing comfort and for mitigating brace migration. An inflatable air bladder is located on an inner surface of the back support for positioning behind the knee. The air bladder has an inflation tube for increasing or decreasing the air volume within the air bladder to affect a range of motion for the patient's knee.