VERT SPORTS OFFICIAL CERTIFICATION PROGRAM
Volleyball Shoe for Female Athletes
Pilot Quantitative and Validation Study
Three of the four athletes completed a minimum of 320 jumps in the RIP-IT shoes, with anywhere from 500-10,000 jumps collected in others shoes to determine their landing impact average. Additionally, the athletes completed sessions during the testing where they performed a practice in their previous shoes to see if there was any change in the average landing impact as well as elevated landing %.
Elevated landing % is defined as landing impacts registered above 15Gs. G-force is a measure of acceleration, with 1G being the constant acceleration we feel due to Earth’s gravity. VERT has collected millions of jumps (and landings) with hundreds of collegiate programs to normalize the data and found landings above 15G to be a key indicator of lower extremity injury, especially athletes averaging more than 20% elevated landings. This was all done using the VERT IMU (inertial measurement unit) device and VTS (VERT Team System) platform.
The landings are measured using acceleration, which provides direct insight into how well athletes are able to attenuate (absorb) ground force from the floor up to their center of mass where the sensor is positioned. The sensor was coupled around the waist in the same place by each athlete, tight to the body under the belly button using the VERT belt. The key to accurately measuring landing is calculated by using a sampling rate high enough to capture the peak acceleration registered to most comprehensively understand the amount of impact absorbed by the athlete's center of mass. VERT uniquely measures at 3,000 Hz (3,000 samples per second), allowing for extremely comprehensive data specifically pertaining to accurate vertical displacement and acceleration metrics.
Jerk & Jolt: The lower the landing impact measured, the less “jerk” or rapid change of acceleration registered at the center of mass. Think of jerk as “jolt.” By lengthening the duration of an acceleration athletes are able to reduce impact and stress on both muscle, tendon and ligament tissues. Jerk / Jolt is similar to the stress you feel as a passenger in a car when the driver slams on their brakes, versus coming to a smooth stop. For simplicity, the higher the landing G the stiffer the landing.
While the ability to stop quickly is a key measure of athleticism, in volleyball, minimizing the peak acceleration on landing is the best way to minimize wear and tear over the course of the season (along with proper load management and strength training).
Participant A
Participant A averaged 2% in elevated landing when wearing her standard shoes and while she dropped to 0% elevated landing in the sessions collected with the RIP-IT shoes. We do not consider anything below a 5% decrease in elevated landing % to be statistically significant. Additionally, this participant left early for college and we have minimal data.
Figure 1.
Traditional range: Average of previous data collection landing impact over 15Gs
AVG HI: Top 87.5 percentile of highest jumps averaged
Jump CT: Number of jumps collected per session
Highlighted (RED) data: Represents when the athlete changed from RIP-IT to previous brand shoe
Elevated Landing Percent Decrease: statistically insignificant as this athlete rarely landed over 15G’s with either shoes.
When assessing individual landing impacts participant A showed a 14% decrease in landing impact. (see Figure 6) This is statistically significant, though additional data with the RIP-IT shoes would be desired. Her average landing G with the RIP-IT shoes was 5.5Gs, whereas her average landing G without the RIP-IT shoes was 6.4Gs.
Average Landing Impact Decrease: 14%
Participant B
Participant B averaged 20% elevated landings when wearing her standard shoes and in over 400 jumps with the RIP-IT shoes in both games and practices. Participant B dropped to an average of 2% elevated landing, with the highest percentage measured with the RIP-IT shoe being 6%. This is a decrease of 90% elevated landing impact.
Upon putting her previous shoes on she immediately averaged 20.7% elevated landing impact.
Figure 2.
Traditional range: Average of previous data collection landing impact over 15Gs
AVG HI: Top 87.5 percentile of highest jumps averaged
Jump CT: Number of jumps collected per session
Highlighted (RED) data: Represents when the athlete changed from RIP-IT to previous brand shoe
Additional notes:
This participant had complained prior to testing of knee pain (tendonitis) and with additional questioning after 3 weeks of training with the RIP-IT shoes claims the pain has been significantly relieved, if not resolved altogether.
Elevated Landing Percent Decrease: 90%
When assessing individual landing impacts participant B showed a 48% decrease in landing impact. (see Figure 6) This is statistically significant and a major change in average landing impact.
Her average landing G with the RIP-IT shoes was 13.9Gs, whereas her average landing G without the RIP-IT shoes was 7.2Gs.
Average Landing Impact Decrease: 48%
Participant C
Participant C averaged 12.4% elevated landings when wearing her standard shoes and in over 320 jumps with the RIP-IT shoes in both games and practices Participant C dropped to an average of 2.7% elevated landing, with the highest percentage measured with the RIP-IT shoes being 9%.
This is a decrease of 78% elevated landing impact.
Upon putting her previous shoes on she immediately increased to 12.2% and 9.1% elevated landing impact.
Figure 3.
Traditional range: Average of previous data collection landing impact over 15Gs
AVG HI: Top 87.5 percentile of highest jumps averaged
Jump CT: Number of jumps collected per session
Highlighted (RED) data: Represents when the athlete changed from RIP-IT to previous brand shoe
Additional notes:
This participant had complained prior to testing of shin splints in both legs and with additional questioning after 3 weeks of training with the RIP-IT shoes claims the pain is gone in one of her legs and significantly reduced in the other leg.
Elevated Landing Percent Decrease: 78%
When assessing individual landing impacts participant C showed a 16% decrease in landing impact. (see Figure 6) This is statistically significant and a major change in average landing impact.
Her average landing G with the RIP-IT shoes was 8.5Gs, whereas her average landing G without the RIP-IT shoes was 10.1Gs.
Average Landing Impact Decrease: 16%
Participant D
Participant D averaged 23.3% elevated landings when wearing her standard shoes and in over 320 jumps with the RIP-IT shoes in practices and scrimmages Participant D dropped to an average of 3.4% elevated landing, with the highest percentage measured with the RIP-IT shoes being 7%.
This is a decrease of 85% elevated landing impact.
Upon putting her previous shoes on she immediately averaged 13% elevated landing impact.
Figure 4.
Traditional range: Average of previous data collection landing impact over 15Gs
AVG HI: Top 87.5 percentile of highest jumps averaged
Jump CT: Number of jumps collected per session
Highlighted (RED) data: Represents when the athlete changed from RIP-IT to previous brand shoe
Additional notes:
This participant has chronic lower back pain but has not had any issues with her back since training with the RIP-IT shoes.
Elevated Landing Percent Decrease: 85%
When assessing individual landing impacts participant D showed an 11% decrease in landing impact. (see Figure 6 ) This is statistically significant and a major change in average landing impact.
Her average landing G with the RIP-IT shoes was 10.2Gs, whereas her average landing G without the RIP-IT shoes was 11.4Gs.
Average Landing Impact Decrease: 11%
The additional notes with each participant are anecdotal and not to be taken as part of the complete study, however we felt having worked with these athletes for years, it was worth noting this information subjectively.
Regarding jumping performance, there has not yet been a statistically significant change either way when wearing the RIP-IT shoes versus the other shoes worn by the subjects. More comprehensive collection is recommended.
Detailed View:
An analysis was also run on peak landing impact (peak Gs) versus inch of jump height. Please see the graph below:
Figure 5:
This analysis shows the following change in peak landing Gs / Inch by participant:
Participant A: 6% reduction with RIP-IT shoes
Participant B: 20% reduction with RIP-IT shoes
Participant C: 15% reduction with RIP-IT shoes
Participant D: 16% reduction with RIP-IT shoes
Average Peak Landing graph:
Figure 6:
Participant A: 14% reduction with RIP-IT shoes
Participant B: 48% reduction with RIP-IT shoes
Participant C: 16% reduction with RIP-IT shoes
Participant D: 11% reduction with RIP-IT shoes
Mean Landing Gs by Jump Height Range graph:
Figure 7:
Only participant B in jump ranges 10”-15” did not show a decrease in average landing Gs when wearing the RIP-IT shoes.
Conclusion:
Regarding landing performance, we feel there is enough data, both objectively and subjectively, to confidently claim the RIP-IT shoes can significantly assist with decreasing the landing impact for female athletes in volleyball. For those who already land well there may not be much of a difference, however our theory posits that most athletes who land stiffly do so, in part, due to a delayed reaction to ground impact. Proprioception and kinesthesia play major roles in how athletes react to coming in contact with the ground. Proprioception refers to the body’s sense of balance and where it is in space. With landing, it plays a critical role as athletes subconsciously take into account how high they are and the body subconsciously prepares for impact. The mind is estimating, using various visual and sensory cues, how much time it will take while having the feet (typically) reach for the ground. The first contact point where our body can physically react is when the feet hit the ground, typically the toes or forefoot first. This now pertains to kinesthetic awareness, which is how we sense our body’s movement, or how well we react to the stimulus of contacting the ground. Poor proprioception can negatively impact movement through imbalance, just as poor kinesthetic awareness can lead to the body being put into precarious or dangerous positions to absorb forces.
This can be affected by the shoes worn by athletes as too much cushion or rigidity may lead to delays in flexion through a dulling of initial ground force sensation. The more complexity placed between the estimations of the brain pertaining to any kind of reaction and reality adds inefficient and sometimes dangerous obstacles to ideal movement execution. These delays, though they may account for milliseconds, can lead to increased “jerk” on the musculo-skeletal structure.
Individual Landing G’s: The results of this pilot study support that RIP-IT shoes may provide a statistically significant decrease in landing impact as measured by the VERT Performance IMU system. Additionally, with the initial study of individual landing G’s (acceleration) we found an 11%-48% decrease in overall landing impact. This represents the most direct evidence of the RIP-IT shoes enabling the athletes to better absorb landing forces up their kinetic chain. This leads to less “jerk” (rapid change of acceleration) and thus less impact on the musculo-skeletal structure of the athletes.
This analysis differs from Elevated landing % in that rather than summarize the number of landings that crossed the 15G threshold, we are able to see in more detail the overarching decrease in individual impacts. For example, what may have been a 16G landing and counted towards the Elevated Landing % was registered as a 12G landing when the athlete wore the RIP-IT shoes.
Landing is one of the hardest impact actions in the sport of Volleyball. A middle blocker at the collegiate level can land upwards of 13,000 times in a single fall season (outside hitters average 7,000-11,000 per season), any decrease to the impact received by the knees, hips and back is critical to a longer and healthier career.
Final overall pilot conclusion:
Average Elevated Landing % Decreased: 63.24%
Average Peak Landing G Decreased: 22.25%
Peak Landing Gs versus Jump Height in Inches Decreased: 14.25%
How Do We Certify Products?
As experts in movement-related-data, our team is able to test a multitude of metrics using our clinically validated IMU (internal measurement unit) and the VTS (VERT Team System) athlete data capture platform to establish trends in performance, be they positive, negative or neutral.
As part of the VERT Certification, programs receive a research proposal once initial criteria is met. Additionally, the research project remains confidential until the results are finalized and there is mutual agreement to share them publicly. The VERT Performance Lab's validation group maintains an unbiased stance, focusing solely on accurate data assessment. Any promotion of the results from the certification process will be at the discretion of the company paying for the certification.
If the results meet the established criteria for achieving VERT Certification, the company will be granted the VERT Certification. Our team will then support by explaining the testing process, promoting the positive results, and providing educational resources to help market your VERT Certification effectively.
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