Test protocol -Prone lying active knee Flexion. A. Correct – Active knee flexion at least 90° without extension movement of the low back and pelvis. B Not correct By the knee flexion low back does not stay neutral maintained but moves in Ext. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.