Stand with shoulder width or narrower stance with thigh against bar. Grasp bar with shoulder width or slightly wider overhand grip. Disengage bar by rotating bar back.
With knees bent, lower bar toward top feet by bending hips and keeping waist straight. Lift bar by extending at hips until standing upright. Pull shoulders back slightly if rounded. Extend knees at top if desired. Repeat.
Throughout lift, keep arms and back straight. Do not pause or bounce at bottom of lift. Do not lower weight beyond mild stretch. Full range of motion will vary from person to person depending on flexibility. Stand on elevated platform if smith machine does not allow full range of motion. Those with less flexibility may have to bend their knees more. Knees can be kept bent throughout movement. Also see Stiff Leg Deadlift.