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| Fig. 1: Painting of all three triple jump phases. (Source: Wikimedia Commons) |
The triple jump is a track and field event that has been a staple of the modern Olympic Games since 1896. Similar to the long jump where competitors land in the sand after running down a runway and leaping from a designated board, the triple jump also employs the same general procedure but with a twist. The difference is that the triple jump is divided into three phases: the hop, step, and jump (see Fig. 1). All three jumps must be executed in a continuous sequence of single-leg bounds: either left-left-right or right-right-left. Broken down, these phases require tremendous amounts of energy and focus from athletes in order to strike a balance between fundamental physics and peak performance.
After sprinting down a runway to a takeoff board, the triple jump begins with a hop. Olympic triple jumpers are incredibly fast and tend to hit the takeoff board at speeds of 9.5-10.5 m/s. [1] At this pace, it is difficult to make sure that speed is carefully balanced when starting their jump. Speed cannot be sacrificed when initiating the hop in order to keep maximal momentum going throughout the jump. The key to this is balancing the tradeoff between height and distance because physics enforces that athletes will jump further based on the higher that they travel given that no speed is significantly lost. [2] An important side-note is that if the foot used to begin this first phase is anywhere past the designated takeoff board, then the entire subsequent jump is marked as a foul and will not be measured. Otherwise, the jump is marked fair and the step phase comes next.
In the second phase, athletes land on the same leg used to in the first hop and skip back into the air. The force exerted by athletes when landing on the ground between the hop and step phases can be up to 22 times their body weight. [2] This typically amounts to approximately a metric ton of weight being applied to one leg! This is the most force that a human limb endures to during any athletic activity known to man. Interestingly enough and likely consequently, researchers discovered that triple jumpers' bones become thicker and denser than normal people's bones in order to combat the intense forces at hand. [1]
This is the final phase of the triple jump. Athletes drive the opposite leg not used in the first two phases down into the ground and try to keep as much decaying momentum as possible going forward. Once airborne, ideally, athletes must reach both legs out in front of them so that their body is at a 90 degree angle. [1] While in this "L" position, athletes simultaneously sweep their arms down past their legs. Pushing the arms down helps your legs come up when landing in the sand. Athletes are measured from the takeoff board to the closest point of their body that touches the sand.
© Fisayo Omilana. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] J. G. Hay, "Citius, Altius, Longius (Faster, Higher, Longer): The Biomechanics of Jumping For Distance," J. Biomech. 26, Suppl. 1, 7 (1993).
[2] A. Eissa, "Biomechanical Evaluation of the Phases of the Triple Jump Take-Off in a Top Female Athlete," J. Hum. Kinet. 40, 29 (2014).
