HOW CHAMPIONS DO IT
Researched, produced, and prepared by Brent S. Rushall,
JENNY THOMPSON AT 90 m OF HER GOLD MEDAL 100 m RACE AT THE 1999 PAN PACIFIC CHAMPIONSHIPS IN SYDNEY
Each frame is .1 seconds apart. Jenny Thompson's time for this event was 54.89 seconds. This excerpt is from the end of the race where the swimmer breathed less and appeared to increase her rating as she approached the finish wall.
Frame #1: The left arm begins the extension phase of the propulsive action. The right leg kicks as the left arm begins to move upward and backward. The right arm enters at almost full stretch. The swimmer's streamline is good with the head well down looking almost directly to the pool bottom.
Frame #2: As the left arm extends backward the left hip rises to facilitate hand and arm extraction. That hip roll is assisted by a left leg kick, the downward kick causing the hip to rise as a reaction. This frame illustrates the start of that kick. At the same time, the right arm extends fully and begins to press down necessitating some of the left kick force to be used to counter-balance the vertical force component of downward press. The swimmer still remains streamlined with the head well down.
Frame #3: The left arm exits as the left leg kick is completed. The right arm continues to press mostly downward. Some of the vertical force created by the exiting left arm will counter-balance the vertical force from the "pressing" right arm. The swimmer is still streamlined in an admirable manner. The right leg prepares to kick.
Frame #4: The right arm is being positioned to create significant propulsion. At this stage, the elbow begins bending and the upper arm medially rotates but only to a partial degree. The right hip is down and must be elevated to allow propulsion to be primarily backward. The right leg begins a downward movement so that the right hip will rise. Still the swimmer is streamlined correctly.
Frame #5: The right elbow is well bent, and the upper arm is in a partial, medially rotated position. This presents the hand/forearm surface as the propelling surface. However, that surface is not vertical, but aligned partly downward. The resulting vertical force component serves to counter-balance the vertical forces created by the recovering left arm. The right leg kick is completed and the swimmer's hips are flat. The left leg prepares to kick.
Frame #6: Propulsion is powered by strong adduction of the upper right arm. The left foot dorsi flexes causing drag and lift forces to result in the hip elevating further. The left leg begins to kick. The head turns partly to the left but not sufficient to allow a breath to be taken. Streamline is still good.
Frame #7: Powerful adduction of the upper right arm has produced strong propulsive forces. The left arm has entered at full stretch causing the shoulders to be flat. The right hip is elevated exhibiting one of the few occasions where hip rotation has preceded shoulder rotation. The left leg completes its kick as the right leg prepares to kick.
Frame #8: Right arm adduction is complete. The left arm begins to press down. The right leg kicks to counter-balance two sets of forces: the vertical component of the extending right arm and the downward press of the left arm. Also, the right leg serves to elevate the right hip to eventually facilitate right arm extraction to start the recovery. The swimmer's head is still well down but appears to be looking more forward than in the previous frames. Streamline is very good.
Frame #9: The right arm is extracted alongside an elevated right hip. The right leg kick is completed. The shoulders rotate downward on the left assisting in a downward-pressing arm action. The vertical force component of the left arm movement will counter-balance the vertical force component of the recovering right arm. The left leg rises preparatory to kicking.
Frame #10: The left arm begins to press down, back, and slightly to the side. Lateral forces created by the recovering right arm require some counter-balancing movement to keep the swimmer directed forward. The outward "press" of the left arm accomplishes most of that role. The left leg is positioned to kick and the right leg begins to rise preparatory to kicking. The swimmer's gaze is forward, an orientation that might require an increase in kick size to maintain the hips in an elevated streamlined position.
Frame #11: As the left arm moves outward, a relatively small left leg movement occurs to counter-balance the lateral force component. This movement is not a kick that contributes to propulsion but rather, is one that acts to cancel lateral forces. The left arm as a unit continues to press down, back, and out. There is no hint of an elbow-up position. The head continues to look forward.
Frame #12: Adduction of the left arm continues to sweep the total arm in a propulsive manner. This is not a particularly efficient action as much energy is directed to vertical and lateral components. An increase in elbow bend does orient the propelling surface more backward. Better positioning could have been achieved if medial rotation of the upper left arm had occurred early in the action. The left foot "drags" down providing some force to initiate the lifting of the left hip. The head still looks forward while its depth contributes to maintaining the good streamlining that has been a feature of this sequence.
Frame #13: Left arm propulsion continues through the latter stage of adduction. In this position, the forces created are mostly horizontal. The right arm enters almost fully stretched. The right leg kicks possibly to counter-balance some lateral and vertical forces produced by a combination of the pulling and entering arms. The left leg prepares to kick.
Frames #14 and #15: The position exhibited in frame #1 is regained and the sequence commences again.
This sequence is near the end of the 100-m race when the swimmer appears to be sprinting to the finish. The duration of the full sequence is 1.4 seconds (frames #1 through #14). This high rate prevents some actions from occurring to their full extent. The amount of hip and shoulder roll seems to be abbreviated. Some compromises that might have occurred with the stroke rate increase are:
- To speed the rolling action, kicks have been introduced that facilitate hip lifting before a propelling arm exits the water.
- The roles of leg movements are complex and not the simple counter-balancing functions for entries and exits that exist in most crawl-stroke swimmers.
- Since the swimmer appears to be increasing her stroke rate, the amount of time available for full hip and shoulder rotation becomes restricted. In this sequence, the range of rotation seems to be quite limited with the swimmer performing most of the stroke largely on the front.
- Another movement that appears to be altered is the latter part of each propulsive arm movement. After reaching maximum depth at mid-pull under the body, the extension action is not directly backward but has a considerable "upward slide" feature. It is not possible to tell if this movement is a deliberate consequence of raising the stroke rate, or a minor fault.
The importance of streamlining in sprinting is clearly evidenced in this sequence. There is no hint of "swimming over the top of the water" or attempting to "hydroplane on the surface."
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