Seat yourself on the machine, planting your feet on the platform spaced widely apart. Ensure that you are pushing your knees out at all times, not allowing them to cave in. Maintain good spinal position with your head and chest up.
Supporting the weight, fully extend the knees and unlock the sled. This will be your starting position.
Lower the weight by flexing the hips and knees, continuing as far as flexibility allows. Do not allow your lumbar to take the load by moving your pelvis.
At the bottom of the motion, pause briefly and return to the starting position by extending at hips and knees.