Board of Certification for the Athletic Trainer (BOC) Practice Test

What angle of knee flexion is most likely to elicit pain during a positive Noble compression test?

1. 0

2. 30

3. 60

4. 90

The correct answer is: 30

The Noble compression test is utilized to assess for iliotibial band (ITB) friction syndrome, which is often seen in runners and athletes. During this test, the subject's knee is flexed and extended while pressure is applied to the lateral femoral epicondyle. The angle of 30 degrees of knee flexion is particularly significant in eliciting pain during the Noble compression test because this position places the iliotibial band under tension as it crosses the knee joint. When the knee is flexed to about 30 degrees, the ITB is at a point where it can become compressed against the lateral femoral condyle, creating friction and pain if the band is inflamed or irritated. As the knee moves into greater degrees of flexion (such as at 60 or 90 degrees), the biomechanics and the alignment of the iliotibial band change, generally reducing the likelihood of pain due to decreased tension across the band and less friction against the lateral condyle. Therefore, 30 degrees is the point at which pain is most commonly reproduced during the test, indicating a positive response linked to ITB syndrome.