Test protocol – Sitting knee extension. Upright sitting with corrected lumbar lordosis; extension of the knee without movement (flexion) of low back A. Correct – Upright sitting with corrected lumbar lordosis; extension of the knee without movement of LB (30–50° Extension normal). B Not correct Low back moving in flexion. Patient is not aware of the movement of the back. 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.