The Squat Jerk While not as common as the split jerk, the squat jerk is often used in olympic lifting competitions. The squat jerk starts the same way as the split jerk, with a dip and an aggressive drive up, but the landing is different. Rather than landing in a lunge stance, athletes land in a squat stance with their feet shoulder width apart. In the last section, I talked about how great the split jerk is for stabilization. The squat jerk allows for some left to right stabilization, but stabilizing forward and backward is extremely difficult in a squat jerk because the feet are next to each other, meaning athletes cannot easily apply a forward or backward force to the ground to balance forward and back. The squat jerk is not nearly as forgiving as the split jerk with regards to balance. This means that athletes have very little room for error in the landing of the squat jerk because there is no easy way to regain stability if it is lost. ​ https://www.iwf.net/2011/11/11/the-winners-are-lu-su-sa-and-perepetchenov/ If regaining stability in a squat jerk is so difficult, why is it used at all? Stability is not the only part of a jerk. The lockout is equally important. Athletes must be able to both lock the bar out overhead and maintain control as they stand up in order for the jerk to be considered successful. The split jerk is better for stability, but the squat jerk is better for allowing athletes to get heavier weights locked out overhead.  The squat jerk allows athletes to decrease the distance the bar must travel because they can drop lower. In a split jerk, athletes cannot drop lower than hips at knee level. The squat jerk allows athletes to drop all the way into a deep squat. This reduces the distance the bar must travel before it is locked out overhead.  The decreased distance helps the athlete because a smaller distance means a larger final velocity of the bar. A kinematic equation that applies to this situation is (Vyf)^2=(Vyi)^2+2ay(yf-yi). That may seem a little confusing, but in plain english, the equation is saying that the square of the final velocity in the upward direction is equal to the square of the starting velocity in the upward direction (whatever velocity the athlete is able to give the bar from the drive up) plus two times the acceleration in the upward direction. While it changes a little bit, throughout most of the lift the acceleration is simply the acceleration due to gravity, or 9.8m/s2. The last part of the equation is the ending height minus the starting height. We can define the initial height of the barbell as the height at the athlete’s shoulders, meaning yi=0. That simplifies the equation to (Vyf)^2=(Vyi)^2-2(9.8m/s2)(yf). In the squat jerk, the final position of the bar can actually be lower than the initial position. That makes yf a negative number. When two negative numbers are multiplied, they make a positive number. This means that the final acceleration of the barbell equals the square root of the initial velocity squared plus some number. The final velocity will be larger than the initial velocity! A larger final velocity of the bar means more time for the athlete to get down under the bar. That is really cool from both a physics standpoint and for the athlete. Athletes can calculate the final velocity of the bar based on the height difference from their hands with arms locked out overhead in the bottom of a squat, to the height of their shoulders when standing. My pictures, Aidan Bailey, squat jerk This equation assumes no forces are applied to the bar after the initial velocity is given. Athletes do apply more forces to the bar. As in every olympic lift, athletes take advantage of Newtons third law. They push up against the bar to keep the bar in the air longer and to let the opposite force that the bar is applying on them push them down faster. This increases the final velocity of the bar and gives athletes even more time to move their body into the receiving position. Because the bar does not need to travel up very far (and in some cases ends lower than it started) to get from an athlete’s shoulders to locked out overhead in the bottom of a squat, athletes do not need to give the bar as much initial acceleration as they would need to with the split jerk to get under a bar with the same mass. This is extremely helpful because as athletes add weight to the bar, they are no longer able to give it as much velocity with the drive at the beginning of the jerk. Using the squat jerk means that a large initial velocity is not necessary to lock even a very heavy weight out overhead. ​ I already mentioned that the squat jerk is not nearly as common as the split jerk. There are a few reasons for that. While the squat jerk is much better for getting under heavy weights, athletes still have to be able to stand up to finish the lift. That is pure strength. Standing up from the bottom of a squat requires a lot more energy than standing up from split stance because of exactly the thing that makes the squat jerk best for getting under heavy loads, the athlete lands much lower. To stand from the receiving position of a squat jerk, the bar must travel a greater distance than from the receiving position of a split jerk. While this is a factor, most olympic weightlifters have no problem squatting the weights they are trying to jerk overhead. In most cases, they have already squatted the weight up from the landing position of their clean. There are two other drawbacks of the squat jerk. One is stability. For the reasons I have already mentioned, stability in a squat jerk is very difficult. Athletes must land almost perfectly to maintain control of a squat jerk. The other reason is mobility. Squat jerks require a tremendous amount of mobility that many athletes simply do not possess. To successfully preform a squat jerk athletes must be able to do a close grip overhead squat with a lot of weight. Many athletes simply cannot. These are things athletes must consider when determining whether to use the split jerk or the squat jerk.