By Noah Kaminsky
Bar clearance is 80% runway speed in the pole vault. The remaining 20% derives from the athlete’s use of the pole. Since technique varies considerably throughout the global pole vault community, this article does not aim to promote one style of the vault over another. Instead, it offers one measure of technical proficiency that everyone should monitor in training and competition.
Call it proficiency, call it efficiency, call it plain old technique. If you’re not tracking an athlete’s “push-off,” then you’re missing a critical factor of that last 20%.
Push-off is the difference between the bar to be cleared and the athlete’s top hand grip on the pole, with an additional 8 inches added to account for the plant box depression. Push-off measures how well the athlete utilizes the pole. The greater the push-off, the more efficient the athlete is with the pole.
Push-off can be negative or positive. Generally, beginners start with higher grips than the bar they need to clear and they produce negative push-off. As athletes progress, they become faster, stronger and more technically proficient, which increases their push-off.
Although push-off might appear to matter only once the athlete leaves the ground, all of the preceding phases of the jump contribute to an athlete’s push-off. Each phase supports the quality and execution of the next phase, in this sequence:
1. Pole Carry
2. Run
3. Plant
4. Takeoff
For example, a shaky Pole Carry can ruin the Run, which then prevents an athlete from planting or jumping up proficiently. If the athlete doesn’t hook up with the pole to meet its unbending, then he/she will not push off the pole adequately either.
Any number of deficiencies can reduce how much an athlete pushes off so it’s critical for coaches to consider more than just push-off alone. Any athletes can produce poor push-off if they don’t jump up at takeoff. This is called “getting ripped off the ground.”
Either the athlete jumps up after the pole tip hits the back of the box, or he doesn’t jump up at all. Getting ripped off the ground ignores the athlete’s ability to jump up and the potential for higher grip. Athletes who favor this takeoff style have accommodated this habit through years of practice because their speed and strength conveniently mask their technical deficiencies. Again, when 80% of bar clearance is speed, it’s easy to hide technical deficiencies like poor push-off.
Push-off is a simple calculation. Every vaulter should know how high he/she grips the pole. Every pole vault coach should know approximately what grip height their athletes use in practice and in competition. Thus, the coach can calculate the push-off after any successful bar clearance. During the warm-up, a vaulter’s grip should gradually increase as he loosens up on the runway. The grip may further increase during the competition, stay the same, or decrease in response to fatigue.
In any competition, grip heights change frequently because the coach will adjust the grip to the athlete’s present performance. Ideally, speed and technique are on point during a competition, but any number of factors on the day of, or leading up to competition, may affect athletic performance. Adjustments are necessary.
Push-off isn’t as easy to determine when you’re watching someone else’s athlete. It’s not impossible to calculate, but it’s certainly more challenging. Your perspective, or the camera angle, may limit your ability to estimate an athlete’s grip. While watching an elite competition, you will often observe a range of push-off numbers because professional vaulters rely on different styles. Some professional athletes emphasize their runway speed more than technique.
For example, in the 2018 season, Canadian Shawnacy Barber jumped on 5.38-meter poles, which are the longest poles ever jumped on by any vaulter. Although Barber’s sprint performances are unavailable online, there are sprint performances available from the current WR holder, Armand Duplantis, and other former WR holders, like Renaud Lavillenie and Sergey Bubka. Duplantis ran the 100m dash in 10.6 seconds during his senior season in high school. Lavillenie ran 60m in 6.63 seconds and 100m in 11.05 seconds. Bubka’s sprint performances are a little harder to uncover online, but he supposedly ran 100m in 10.2 seconds. As fast as these vaulters are (or were), none of them ever gripped as high as Barber has. Bubka, Duplantis and Lavillenie had higher push-off numbers than Barber because they jumped on slightly smaller poles with lower grips. They were more efficient!
Push-off in the modern fiberglass era ranges between 0-24 inches for youth athletes and 24-48 inches for older athletes. Surprisingly, prior to the use of fiberglass poles, these averages were remarkably the same, or better, for the best vaulters. Ken Doherty’s Track & Field Omnibook (2nd ed.), published in 1972, reports an average grip height of 13 ft 2 in for pre-fiberglass vaulters for an average bar clearance of 15 ft 2 in. This suggests pre-fiberglass vaulters jumped over their grip with an average push-off of 32 in. When fiberglass was introduced, the average clearance height increased to 16 ft 9.5 in, and grip heights increased to an average of 14 ft 10 in. Although athletes could hold the pole higher than ever before, the differences calculated between respective grip height and bar clearance remained nearly identical. In other words, athletes could jump higher, but they remained similarly efficient with their use of the pole.
As with all innovative change in sports, the transition to fiberglass brought about controversy because “its opponents claimed that performance now was an effect of the catapult action of a machine rather than of human ability.” While this may be true for increasing grip height on the pole, the “catapulting effect” provided no immediate benefit to the athlete’s ability to jump above their grip. Push-off saw no remarkable change between the pre-fiberglass and the modern era of pole vault. Today, straight-pole jumping drills are just as valuable as they were to athletes who used stiff poles made of bamboo, aluminum or steel.
As noted earlier, measuring push-off for professional vaulters is challenging because this data is not widely available or often recorded. Though pole specs are infrequently available, some of this information has emerged over the past several decades from sources like the online forum PoleVaultPower, various educational seminars, and interviews with athletes and their coaches. Bubka has been helpful to the pole vault community because his performance data is more available than most other vaulters. Today, he continues to champion sports education in his home country, Ukraine, and to the next generation of Olympic hopefuls worldwide.
In 1984, Bubka gripped 16 ft 9.5 in and jumped 19 ft 9 in. When accounting for the 8-inch dip in the plant box, his push-off was 43.5 inches, or 3 ft 7.5 in. In 1991, when Bubka jumped his final WR, his push-off was 40 inches, indicating that he ran incredibly well on the runway and utilized the 5.10m pole only slightly less efficiently than 7 years prior. If Bubka gripped the same height in 1991, and produced the same push-off from 1984, then he would have cleared 20 ft 5 in or 6.22m, which is 4 centimeters higher than Duplantis’ current WR. However, numerous other factors influence any given performance and it’s unreasonable to posit what’s possible from the numbers alone. I hope this brief look at Sergey Bubka’s performances offers a mandate for coaches and athletes to track their push-off over time.
The highest bar cleared remains our performance gold standard. This should not change. However, it is not the only measure of ability. Push-off measures an athlete’s technical efficiency. Push-off offers perspective on an athlete’s bar clearance potential. Tracking and monitoring push-off allows coaches and athletes to assess progress. If an athlete jumps higher, while his push-off decreases, then he may have gained speed on the runway at the cost of technical proficiency. Alternatively, if an athlete jumps the same, or clears a lower bar, but his push-off increases, then he may have lost speed, but remain technically proficient. Both are necessary to create sustainable progress in the pole vault.
When 80% of the jump is produced from an athlete’s speed, it may seem less important to coach the last 20%. Even with the most effective training, athletes, male or female, have genetic limits which prevent them from producing enough speed to roll their pole to vertical. A vaulter’s grip cannot increase indefinitely. The tradeoff between grip height and safety is not worth the liability. Grip should progress when vaulters consistently overcome pole resistance and they land safely in the pit. Until then, keep the grip fit to the vaulter’s ability. Teach them how to get their hips above their grip. Teach them how to push off!