Movement:
Hold the edge of a rope or a bar with an Underhand grip. VIdeo performed with an Overhand grip due to the attached piece of equipment, I prefer you using an Underhand grip.
No shoulder or pulling action from your arms, and no jerking movements either. Contract your abs (performing a spinal flexion movement) to bring the weight down and control the action back up, resisting the weight as you return to the starting position.