FABER-SI or FA?

We’re all familiar with the FABER (Flexion-ABduction-External Rotation) Test used in lower quarter assessment but what joint is it really testing? Sacroiliac or Femoroacetabular? The answer is both. The difference is the pain provocation pattern. Compressive forces will be through both articulations but SI provocation will present posteriorly while FA will present anteriorly. Sensitivity for SI will range between 36-77% while Specificity ranges between 16-100%. Sensitivity for FA is 54% while Specificity is 88%. Remember to place the ankle above the contra-lateral knee to avoid false findings. See you next month.