We are updating the definition of Jump Height in our jump and hop-based tests to align our approach more closely with emerging industry standards and current research literature.
SUMMARY
We are updating the definition of Jump Height in our jump and hop-based tests to be measured from the point of take-off. This change aligns our approach more closely with emerging industry standards and current research literature.
JUMP TESTING BACKGROUND
Jump testing is a vital component in both sports performance and physiotherapy, providing an effective means to assess lower-body power, strength, and coordination. Tests such as the vertical jump and countermovement jump are particularly useful for tracking an athlete’s recovery following injury, ensuring they are regaining function and strength. In the realm of sports, jump testing evaluates explosive power and athletic readiness, often acting as a key benchmark for performance improvements. By analyzing jump mechanics and results, practitioners can identify weaknesses or imbalances, adjust training programs, and support a safe return to play while enhancing overall performance.
JUMP HEIGHT DEFINITIONS
Defining jump height is more complex than it may initially seem, as there is no universally “correct” definition. Each method offers a valid and reliable means of assessing an individual’s vertical jump performance, with the choice often determined by the available measurement technology. Here are three commonly used definitions:
- Jump and Reach (or Sargent Jump): This method calculates jump height as the difference between an athlete’s standing reach and the highest point of contact after jumping. It’s the simplest and most accessible option, requiring only a wall and chalk, or basic equipment like a Vertec.
- Take-Off to Peak Height: Here, jump height is measured as the displacement of the center of mass (COM) from the moment the feet leave the ground to the highest point of the jump. This method requires more advanced equipment, such as force plates or jump mats.
- Standing to Peak Height: This method measures the displacement of the COM from a standing position to the maximum elevation of the jump. It requires specialized technology, such as force plates or video-based biomechanical analysis.
Why Are We Changing Our Jump Height Definition?
Until now, the AxIT System has used the “Standing to Peak Height” definition for measuring jump height. This approach was originally chosen because it captures the full elevation achieved during a jump, including the pre-takeoff phase, aligning with the intuitive expectation of how high an athlete jumps. However, since the launch of the AxIT System, the field of jump height measurement has evolved significantly. With the increased availability of specialized jump testing technology and a growing body of research, both professionals and clients now have a deeper understanding of these measurements.
The “Take-off to Peak Height” definition has since emerged as the de facto standard, likely due to its compatibility with simpler measurement tools like jump mats, and the fact that the “Standing to Peak Height” method poses challenges in specific tests, such as drop-jumps.
In response to these advancements, we have decided to adopt the “Take-off to Peak Height” definition in the AxIT System moving forward.
WHY NOT INCLUDE BOTH?
At Strength by Numbers, we prioritize simplicity. For most applications outside of elite sports performance, only a few key metrics are needed to effectively assess your clients. Our focus is on providing client-centric solutions, where offering a small number of clear and actionable metrics is far more effective for client engagement than overwhelming them with excessive data. This is why we choose to include a single jump height metric, ensuring that the information is both accessible and impactful.
HOW WILL THIS CHANGE AFFECT ME?
You may notice a slight reduction in your jump height results due to the new definition, which no longer includes the displacement of the center of mass before take-off.
It’s important to exercise caution when comparing results across different systems, whether in practice or in research literature. Small differences in algorithm implementation and testing protocols can significantly impact outcomes. To address this, we’ve developed our own benchmarks using data from AxIT customers. However, with this new jump height definition, your results will now be more closely aligned with the data found in most published research and other commercially available force plate systems, allowing you to better interpret your AxIT results in comparison to other sources.