Jerk Phase
This phase begins by movement by using the synergy of different regions of the body in one swift action, and these will be the upper extremities, shoulders, hip, and ankles. Dip your body by bending knees and ankles slightly to provide force to drive the bar off the shoulders and straight up by using the triceps and anconeus to extend the elbow. The shoulder girdle will upwardly rotated and elevated by the Trapezius, Levator scapulae, and Serratus anterior and the shoulder joint muscles Pectoralis major, anterior deltoid, coracobrachialis and the biceps brachii will be in flexion. Immediately drop body downward slightly and split one leg forward and back; the leg forward will be in flexion and the leg backward will be in extension in the sagittal plane which will cause right and left pelvic rotation to the hip in transverse plane. One knee will be flexed (decreasing the angle between the femur and lower leg) with the leg that’s forward, the other knee is slightly flexed to absorb the weight with the leg extended back.
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As for the ankles, the ankle with the leg forward is somewhat dorsiflexed, but the ankle with the leg that’s in extension is plantar flexed with the balls of your feet driving into the ground and your calcaneous (heel) being posterosuperior. After that, push up with both legs primarily using the knee extensors the quadriceps and hip extensors in the forward leg, and use gastrocnemius and soleus in the back leg to give more force to restore the leg to anatomical position. When returning to anatomical position the hip are leaving their rotation in the transverse plane
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