The clinician suspects that a client has patellar instability. In order to test for this, the client is seated with the quadrice
ps relaxed, and the knee is placed in extension. Next the patella is displaced laterally, and the knee flexed to 30°. If instability is present, this maneuver displaces the patella to an abnormal position on the lateral femoral condyle, and the client will perceive pain. Testing for patellar instability in this way is known as.
The sign of apprehension is a provocative test to identify patellar instability. In this test the client is sitting with the quadriceps relaxed and the knee is placed in extension. Then the patella is displaced laterally and the knee flexed at 30 °. If there is instability the client will put his hand avoiding the continuity of the test, because he will feel pain. In addition, if patellar instability exists during this test, the client will contract the quadriceps for fear of dislocating the patella and will verbally report the pain as: "stop if you won't dislocate my knee", "my patella will leave from the place, stop! "
