I have known OA, have had meniscuses surgery bilaterally over the last 3 years. Moderate OA in this knee. Age 57. Having pain behind knee more toward the outside lateral then directly behind knee. Hurts to bend the knee, hurts when walking and standing, hurts even at night when trying to sleep. When trying to bend knee it (leg) feels heavy. At night it is more a throbbing pain that is not positional. I can walk into a store and within 15 minutes pain is bad and by the time I get back to the car very difficult to bend knee to get into the car. No known injury or even movement that initiated the problem. Massage therapist thinks it is the IT band- she worked the area and for about 30 minutes afterward I could bend the knee without pain and no heaviness. I do have an ortho apt in 3 weeks. It does not feel like previous knee pain.