Key Issues of Jerk Technique
This article focuses on Jerk technique, the second part of the competition movement known as the Clean and Jerk. In particular, the article discusses the conventional technique of the ‘Split Jerk’ which is employed by the vast majority of Weightlifters worldwide. While the author acknowledges that World Champions have used the ‘Power Jerk’ or ‘Squat Jerk’ techniques, the Split Jerk technique is recommended as the most effective and the safest.
From this point on, the Split Jerk technique will be referred to simply as “The Jerk”
Key Issues of Jerk Technique
The Jerk is a highly complex movement that many athletes in Weightlifting find harder to master than the Snatch. In the Jerk, athletes must overcome several key issues if they are to become good exponents of the lift. These key issues are:
Issue 1: The extreme heaviness of the barbell
Exceptional performers in the Clean and Jerk will lift as much as 80% of their best Back Squat. This weight must be lifted to approximately 110% of the athletes height. The physical work done during the Clean and Jerk is more than any other movement in Weightlifting. Figure 2, an athlete of 1.68m in height, raises the bar a total of 1.85 metres in three stages:
- The Pull – 76cm
- Rising out of the Clean – 62cm, and
- The Jerk – 48cm
To lift a weight that is 80% of maximum Back Squat a total of 1.85 metres requires not only excellence of technique but also great courage, will power and tenacity.
The average Weightlifter will have difficulty comprehending the extreme heaviness of the barbell at the highest level of Olympic Weightlifting. Lifts of around 2.6-2.7 times bodyweight are common at World Championships and podium finishes require considerably more. Athletes of this standard would have extreme difficulty deadlifting their best Clean and Jerk on the average training day without a significant warm-up.
Issue 2: Achieving and maintaining a lockout
In Olympic Weightlifting, achieving a lockout has exceptional importance. No matter how strong the athlete is in lifting the barbell, in a competition, the Weightlifter must complete the lift to the satisfaction of the three referees who will apply the international rule. Any slight unevenness of lockout or hint of a press out will, if seen by the referees, almost certainly result in red lights.
All athletes in Olympic Weightlifting will occasionally have mishaps with defective lockouts but those who come into Weightlifting from another barbell sport frequently have major problems in this area. The key is effective coaching of the lockout from day one of an athlete’s training. Here is a great example of the specificity principle. An athlete might be extremely strong in the bench press or shoulder press, but entirely useless in the lockout. The probably main causes of this issue are poor shoulder flexibility and a lack of specific lockout training. These two main causes are linked.
Issue 3: Balance
Even when both elbows are locked out, the athlete will experience significant difficulty in maintaining balance and control of the weight overhead. In the situation where the athlete has a barbell of twice body weight overhead, the combined centre of mass (of the barbell and lifter) will be situated at approximately neck height or higher (see figure 2 below). The higher the combined centre of mass, the greater the balance problem.
This very high combined centre of mass means that even a momentary loss of balance which causes the bar to displace forwards, backwards or sideways can cause the athlete to lose control. The more the athlete is at the extreme limit of their capability, the more likely they cannot regain control. For this reason, coaches must place emphasis on athletes practising balance in the receiving position, and slow and cautious recovery to the finishing position.
Issue 4: Stability of Body Structure
The Jerk is a movement that is unforgiving of any weakness in the position of the body in the receiving position. An athlete may elevate the bar high enough, and have sufficient lockout strength in the arms, but if the rest of the body is not positioned correctly to support the bar, then the lift is likely to be lost.
Figure 4 represents an ideal body structure in the Jerk receiving position. Although a different athlete, the body position is similar to Figure 1 displayed by Yanko Rusev, former World Champion and World Record Holder in the Clean and Jerk.
Key factors that create body stability under the bar are:
- The vertical alignment of the bar, shoulders and hips. This vertical alignment minimizes the amount of torque (rotational force) experience by the athlete.
- The centre of mass is directly over the base of support.
- The spine is well supported by a cordon of strong musculature in the upper body. This again requires specificity of training.
- There is equal pressure on both feet and an evenness of force through both legs as a result.
- The angles of the lower body can be held in the moment of lockout and arresting the bar overhead. In this moment, the athlete will be squeezed downwards.
- The shoulders remain stable while the bar is locked out overhead.
A common receiving position error as depicted by Figure 5 , shows an athlete with a body structure that is unstable. A key cause of this instability is the tendency of athletes to straighten their back leg in the moment of receiving the bar overhead. The straight back leg also causes anterior pelvic tilt and a pronounced forward lean of the torso. As a result, the hips are clearly behind the bar and the weight of the bar toward the front of the base. These factors will cause the athlete to have significant difficulty in maintaining balance and stability of the bar overhead.
The receiving position as shown by Figure 5 also results in an unequal distribution of weight on both feet and a reasonable possibility of the back foot slipping.
Issue 5: Pelvic Alignment Issue
Another all too common issue that arises in the Jerk is anterior pelvic rotation as depicted in Figure 6 . Rotation of the pelvis in a forward direction necessitates hyper-extension of the lumbar spine to enable the athlete to stay upright. Any adverse or exaggerated curvature of the spine increases the risk of injury under heavy load. Anterior pelvic rotation will also exacerbate the balance and stability of the athlete when the bar the bar is overhead. For these reasons, it is a very high priority for beginners in Weightlifting to engage in exercises and skill drills that focus on awareness and control of pelvic alignment.
A skill drill as depicted in Figure 7 is a safe place to start teaching pelvic alignment.
Other exercises that should be prominent in the beginner’s program include:
It is important to take a long-term approach, from the very first moment that training begins, toward achieving total confidence and positional correctness in Jerk technique. Coaches should understand that the skill learning process should not be rushed. Errors that accumulate early in the learning process are hard to correct later. It is unfortunate that beginning athletes can often succeed with Jerks despite poor technique but as the athlete progresses to higher levels of qualification, the special issues described above will undoubtedly diminish the athlete’s performance potential unless appropriate attention is given.