Varus and valgus stress tests are physical therapy assessments that are designed to test the stability of the knee joint. In the valgus test, the knee is moved away from the body, and in the varus test the knee is bent inward, towards the center of the body.
In both tests, the examiner grips the patient by the knee and ankle. He then attempts to move the tibia laterally without moving the femur. The initial tests are generally done with the leg pointed straight out at a zero degree angle and then repeated at 20 degree and 30 degree angles to test the knee's full range of motion.