The snatch, the first of two lifts in Olympic competition weightlifting is considered the most demanding of weightlifting exercises. During the snatch the weight must be lifted to an overhead position in one continuous movement. The lifter must keep the barbell under control whilst standing upright and maintaining the overhead bar position. This one movement combines all aspects of human sports performance including mental concentration, speed, strength, power, balance, and muscular coordination.
A description by Derwin (1990) states the basic principle of the snatch quite simply as vertically accelerating the barbell to a sufficient height, enabling the lifter to rapidly move beneath the bar and support it in an overhead full squat position. The lifter must then obtain control and stand erect.
Burdett (1982) describes the performance objective of the snatch as pulling the bar high enough to squat beneath, as the weight is held overhead. The lifter then stands up from the squatting position keeping the barbell overhead and under control.
The primary purpose of this analysis is to investigate the biomechanics of the snatch and determine joint angles that influence the performance of the lifter.
QUALITATIVE ANALYSIS OF THE SNATCH
The snatch is a total body exercise that is extremely dynamic encompassing a variety of extension and flexion movements. In order to correctly perform the snatch there are five key phases involved. It is the transition from one phase to another performed in a mechanically efficient manner that translates to the successful execution of this exercise.
Phase I - The Start Position
This phase begins the moment the lifter separates the barbell from the floor, and ends with the barbell just above knee height. The lifters feet are placed shoulder width apart under the bar and angled outward as much as 15°. The hips are above parallel and the shoulders are directly over or slightly in front of the bar. The actual movement of the barbell is proceeded by the lifter removing any slack from the body and the bar. The contraction of the quadriceps, gluteals, and erector spinae begins the movement of the bar upward and slightly back to the position just above the knees. During this phase the angles of the ankles, knees and hips all start to open. Ideally, the back maintains the same angle with the floor from beginning to end of the phase. At the finish of the movement the latissimus dorsi are contracting to pull the bar toward the thighs while the arms remain straight. It is the view of Derwin (1990) that the speed of the bar is governed by how fast the lifter can accelerate the bar and still maintain correct body position.
Phase II - The 1st Pull
The bar is at knee height with back and shoulders identical to the floor position. Arms are straight with elbows pointing along the bar. Lower back remains flat by simply straightening the legs and imparting force onto the floor. In the transition of the bar from the floor to knee height the legs and hips drive simultaneously in order to overcome the inertia of the barbell. The bar remains close to the shins in the transition from phase I to phase II. When the bar is at knee height it is over the centre of the feet, ensuring that the lifter remains balanced throughout the transition.
Phase III - The 2nd Pull
The bar is at mid thigh height with the legs at full extension on the balls of the feet. Shoulders are shrugged and the body is in an upright position with the arms straight. This position is attained by driving the hips slightly forward and upward in an explosive manner and is a continuation from phase II. It is important to keep the forward component of the hip drive to a minimum in order to apply maximum vertical displacement of the bar and limit any horizontal motion. The dynamic hip drive fully engages the hamstrings and gluteals with the trapezius responsible for the shrugged position of the shoulders. During phase III the bar reaches maximum vertical velocity.
Phase IV - The Descent & Catch
This is often seen as the most critical phase of the snatch. Phase IV lasts until the bar no longer has any vertical velocity, the bar will reach its apex and begin to descend. In the transition from phase III to phase IV the bar should travel in one continuous movement vertically, maintaining close positioning to the upper body. The objective of phase IV is to actively move the body under the bar in preparation for the catch. Finally, there is a settling into the full squat position to assume control. In this position the bar, shoulders, hips and ankles are in a vertical line, with the arms locked.
Phase V - The Recovery & Final Position of Recovery
Once the lifter is under control in the squat position, the contraction of the gluteals and quadriceps begin to straighten the legs. It is important to keep the bar, shoulders and ankles in a straight line to limit the chance that the hips may rise too fast and tilt the lifter forward increasing the risk of imbalance and therefore a missed lift. When the lifter is fully erect with the arms maintain the locked position and the feet are brought closer together increasing stability in the base of support. Once the lifter has shown control in this position, the down signal is given by the judges allowing the lifter to return the bar to the platform.
- Burdett, R.G. (1982). Biomechanics of the snatch technique of highly skilled and skilled weightlifters. Research Quarterly Exercise & Sport. vol 52, 3, pp.193-197.
- Grarhammer, J. (1985). Biomechanic profiles of Olympic weightlifters. International Journal Sport Biomechanics. vol 1, 2, pp.122-130.
- Derwin, B.P. (1990). The snatch: Technical description & periodization program. National Strength & Conditioning Journal. vol 12, 2, pp.6-9; 80-81.
- Walsh, B. (1991). Exercise technique: The power snatch. Sports Specific Journal. vol 13, 1, pp.29-31.