Fig. 5

The Double-Leg Lift-Alternate Leg Extension. (Illustrations adapted from Monnier et al.: Inter- and intra-observer reliability of clinical movement-control tests for marines. BMC Musculoskeletal Disorders 2012 13:263). Purpose: To test the ability of preventing extension, flexion and rotation of the lumbar spine, as well as leg abduction and lateral rotation. Test movement: A pressure biofeedback unit was initially positioned between the lumbar lordosis and bench and inflated to a pressure of 40 mmHg. Then a bilateral leg raise from a supine (crook lying) position was performed to 90° hip flexion, following by a unilateral lowering of the leg to a fully extended position, and then again returning back to 90° hip flexion, repeating with the other leg, and finally bilateral leg lowering back to the crook lying starting position. Pass Criteria: <5 mmHg pressure change, with the extending leg not moving away from the midline or turning out