Use a weights bar, or other similar for this exercise.

Stand with your feet shoulder-width apart, holding the bar in front of you. Lean forwards from your hips, and bend your knees slightly. Put yourself into the Neutral Spine Position, shoulder blades in the Butterfly and keep them locked throughout.

Raise the bar towards your stomach just below your belly button, and lower it, all the time with a smooth controlled motion, keeping the core engaged and the shoulder blades locked in place. Keep your shoulders back and don't let your shoulder blades move even when lowering the bar.