Hook feet under foot brace and lie supine on incline board with hips and knees bent. Hold plate on chest with both hands or use no weight.
Flex and twist waist to one direction while raising torso from bench by bending hips. Return until back of shoulders contact padded incline board. Repeat to opposite side alternating twists.
Crossed arms can also be brought up above knees at top to increase range of motion. Exercise can be performed without added weight until more resistance is needed. Elevate incline to increase resistance. See Arm Position During Waist Exercises. If no knee support is built in to incline board, ball can be placed under legs as illustrated. Elbows can be raised over opposing knees for fuller range of motion. If upper back does not come completely down at end of movement, abdominal muscles may only be isometrically involved in exercise. Pectineus, Adductor Longus, and Brevis do not assist in hip flexion since hips are already initially bent. Knee flexors may be involved as stabilizers if incline is steep and no calf support is used. See Spot Reduction Myth.