Imagine running at full speed carrying a 15 foot long pole. You approach a large foam mat and a high bar spanning across two rigid standards. Once you are a few feet away from the mat, you lower the front tip of the pole into a hole in the ground, raise your arms up towards the sky, and jump as high as you can. In less than a second, the pole bends and you swing your legs up above your head so that you are completely upside-down. Your body is launched upwards, and once the pole fully recoils, you let go and suddenly find yourself floating 17 feet above the ground. Just as quickly, you plummet back towards the earth and come to rest comfortably in the middle of the foam mat (for illustration, see Fig. 1)

You have just successfully completed a pole vault, one of the most dynamic track and field events in modern competition. The sport requires an all-around athlete with the speed of a sprinter, the jumping abilities of a high jumper, and the strength of a thrower. Unbeknownst to many, pole vaulting also requires an engineer to develop pole technology to efficiently absorb and transfer energy. The result is a gravity-defying phenomenon in which vaulters seem to soar effortlessly into the air.

Pole vaulting, in its non-competitive form, has existed since the days of the ancient Greeks, when it was used to surmount obstacles such as enemy walls or to vault over or onto animals such as bulls and horses [1]. In 1775, poles were implemented into gymnastic competitions in Germany for a vertical jump event. Finally, in 1850, the first “running pole leaping” competitions were held, and since then, the sport has grown to become a staple of high school, collegiate, and international-level competitions [2].

The vault is a complex, yet seemingly fluid and graceful process that utilizes almost all of the core muscles of the body and requires a large amount of practice and skill. For the purpose of explaining how pole vaulting works, this complex process can be broken down into four basic steps: the approach, the plant/take-off, the swing-up, and the push-off.

The approach allows the athlete to build up speed and prepare for the plant and take-off. The vaulter starts from a standing position, places his hands spaced apart at one end of the pole, holds the pole in a vertical position, and then slowly lowers the tip of the pole as he approaches the box and pit. During the plant/take-off, the vaulter lowers the pole tip into the back of the box, raises his arms up above his head (with the left hand about a foot farther forward on the pole for a right-handed person), and jumps up off the ground while still maintaining his forward momentum. These actions result in the pole bending and gaining energy, which will later be used to propel the vaulter upwards (Fig. 2). During the swing-up, the vaulter swings his legs up over his head towards his hands, bringing his body upside-down and in line with the pole. Once upside-down, he “pulls” the pole against his body and past his head, performing a handstand on top of the pole. This then leads to the final step, the push-off, in which the vaulter throws himself off his pole and curls himself over the bar, while at the same time rotating his body so his stomach is facing towards the ground. These movements allow the vaulter’s body to contort over the bar with more ease. Finally, the vaulter falls back to the pit and comes to rest on his back [3].

Pole vaulting relies on finding the most efficient way to transfer energy among different energy states. These states are kinetic energy, or the energy associated with the motion of an object, and two different types of potential, or stored, energies: elastic potential energy and gravitational potential energy. Elastic potential energy is the “energy stored in elastic materials [in this case, the pole] as the result of their stretching or compressing,” while gravitational potential energy is the “energy stored in an object as the result of its vertical position or height,” [4]. During the vault, the kinetic energy built up during the run (KE_approach) is transferred into elastic potential energy due to the bending of the pole (PE_pole.) Then, that potential energy is transferred into kinetic energy as the athlete is vaulted upwards (KE_vault.) As the athlete rises above the ground, this kinetic energy is transferred to gravitation potential energy (PE_peak) until the athlete is not moving any higher. Finally, this potential energy is turned back into kinetic energy as the athlete hurls towards the ground (KE_fall.) Thus, the pole serves as a tool for converting the athlete’s horizontal kinetic energy into vertical kinetic energy. Equation 1 shows a symbolic progression of this process and Fig.4 highlights the energy changes in an animated example.

Through the transfer of energy, a vaulter is able to launch himself up to 20 feet in the air, depending on his speed and weight. The greater the vaulter’s speed and mass, the more momentum he can build up during his approach, and thus the more energy he can transfer into the pole. Using a man with a center of mass 1.0 meter off of the ground who can run with a speed of 10 meters per second as an example (values for an elite athlete), the formula predicts that he should be able to vault about 6.10 meters high [5]. This result is surprisingly accurate, considering that the world record is currently set at 6.14 meters, a mark achieved by Sergey Bubka of Ukraine in the early 1990s. The slight differences between the theoretical and actual heights have to do with the pole’s efficiency in transferring energy, which will be discussed later.