Getting Under the Split Jerk Properly
There are two kinds of people in the world: those who are good at the jerk, and those who are not. For the latter group, there are so many things that can go wrong or be misunderstood that it can be very daunting to correct the movement. One of the big problems is moving into the split posiiton properly.
First, it's important to understand that the dip and drive of the jerk, whether split, power or squat, is vertical. In fact, the bar actually needs to move backward slightly as it moves into the final overhead position. Often when doing the split jerk, athletes will drive forward and dive toward the front foot. You have to be patient: finish your vertical drive and only then begin to split.
When moving into the split position, keep the hips under the bar (this may feel like pushing the hips forward slightly) and reach the front heel forward. Don't reach with your chest. Leading with the chest will pull the hips out from under the bar, cause the back foot to over-reach, and the front foot to reconnect too soon and too close. The effect is a bar forward of a base that isn't balanced, even if the bar actually moved straight up. Let the chest move forward the slight amount it needs to in order to achieve the proper overhead position naturally by focusing on moving the bar back over the base of the neck and locking the shoulder blades back together. Keep the back foot close to the floor and pick up the front foot enough to get it out far enough and landing flat. Your weight should be balanced about evenly between your front and back feet and the hips right under the bar.