Place feet under low overhanging stationary object. Lie supine on floor or mat with hips and knees bent. With both hands, hold plate on chest with forearms crossed.
Flex and twist waist to one direction while raising torso from bench by bending hips. Return until back of shoulders contact floor or mat. Repeat to opposite side alternating twists.
Exercise can be performed without added weight until more resistance is needed. Add more weight or perform on incline board to increase resistance. Also see Arm Position During Waist Exercises and movement with weight placed behind head. 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. See Spot Reduction Myth.