After the bar is lifted off the ground in the “first pull”, you must then pull the bar through the knees and into the hip. This is called the “second pull.” The most common faults in the second pull are found in the knees and shoulders.
First, the bar doesn’t travel around the knees; it travels through them. If you try to move the bar’s path around the knees, you will have a loss of power and either have to jump forward or backward in order to catch the weight. For this reason, a lot of olympic lifting coaches will teach the “diamond technique”, which is driving your knees out as you deadlift the bar through your knees.
It’s called the diamond technique because the knees are driven outside of the feet, causing a diamond shape with the feet, knees, and legs.
The second fault is found with the shoulder placement. In the snatch and clean, you have the “high-hang”, “hang”, and “low hang” positions. I review each of these in the video below, but what’s important is that the shoulders stay over the shoulders during all three hangs. The shoulders only come behind the bar between the high-hang and the power position.
The best way to work on this is with an empty barbell. Hit each position slow in your warm-up. Pick up speed with each rep until you are going full speed. Then, start loading on the weight.