Most people perform the lat pull down incorrectly. Sit with pad under your thighs; lean back between 5-40 degrees & HOLD THAT POSITION throughout the exercise. Use a controlled movement bringing the bar down to the upper chest and a controlled movement back up; not too fast. Most exercisers use too much momentum (i.e., go too fast) when performing the lat pull down. DO NOT ROCK back & forth with your torso. DO NOT PULL DOWN BAR BEHIND THE NECK because: 1. you do not work the back muscles any better behind the neck, and, 2. there is POTENTIAL RISK OF INJURY/IMPINGMENT to the shoulder (rotator cuff) and the cervical spine.