If you’ve never used a jump platform in your practice as a coach or physical therapist, you’re probably leaving on the table the most accessible, fastest, and most informative assessment tool that exists for measuring your athletes’ neuromuscular performance.
If you already use one, this article will help you get more out of it: understand what each test says, how to interpret it, and how to connect that data directly with training programming.
Let’s start from zero.
A jump platform (also called a contact mat) is a device that measures the time the athlete spends in the air during a jump and the ground contact time when executing that jump.
From that flight time, the system calculates jump height using the formulas of projectile motion physics.
It’s a tool that in the ’90s was reserved for high-performance laboratories. Today, with platforms like Nexo Jump, it’s within reach of any coach or physical therapist, and it’s portable, with Bluetooth and cloud storage included.
The athlete starts from a squat position (90° knee flexion), with no prior countermovement, and jumps as high as possible.
What does it measure? The ability to generate explosive force from a static position, without exploiting the stretch-shortening cycle (SSC). It’s a relatively pure measure of lower-body concentric strength.
What is it for? It serves as the base of explosive strength. If an athlete has a low SJ, they need max strength work before plyometrics.
The athlete starts standing, performs a countermovement (a quick descent), and immediately jumps up.
What does it measure? The ability to exploit the stretch-shortening cycle to enhance the jump. The CMJ is almost always higher than the SJ in well-trained athletes.
What is it for? The difference between CMJ and SJ (called the elastic utilization index) says a lot about the athlete’s neuromuscular efficiency. A CMJ much higher than the SJ indicates good elastic reutilization. A CMJ similar to the SJ indicates a deficit in that capacity.
The athlete drops from a set height (typically 30-40cm), touches the ground, and immediately jumps up trying to minimize contact time.
What does it measure? The ability to absorb and reuse elastic energy in a very fast stretch-shortening cycle. The Reactive Strength Index is calculated (RSI = flight time / contact time).
What is it for? It’s the most specific measure of plyometric capacity and tendon stiffness. Athletes with a low RSI need specific reactivity work. Athletes with a high RSI can tolerate higher plyometric loads.
The same tests (SJ, CMJ, DJ) executed on one leg allow comparing performance between the dominant and non-dominant limb.
What is it for? An asymmetry greater than 10-15% between legs is an injury risk indicator and a signal that the plan should include unilateral corrective work before scaling bilateral loads.
The isolated number (“they jumped 35cm”) doesn’t say much. What matters is the context:
The most valuable data isn’t comparing the athlete to external normative tables, it’s comparing them to their own baseline. A CMJ that drops 8% from the previous test is a fatigue or overtraining signal, regardless of the absolute value.
The relationships between SJ, CMJ, and DJ are diagnostic:
Tests deliver their greatest value when repeated systematically across training blocks. The trend, improvement, stagnation, or decline, is the most important information for adjusting programming.
In Nexo Kinetics, all tests are saved to the cloud and the software automatically generates the visual comparison between tests over time. The analysis of the results is performed by the platform’s internal analysis engine, which evaluates different dimensions of the athlete’s neuromuscular profile and generates a specific prescription for each one. For example, from the RSI of the multiple-jump test it classifies the athlete’s reactive strength level, from severe deficit to world-class capacity, and prescribes the work corresponding to that level.
You don’t need any external spreadsheet to see the evolution.
Run the three basic tests (SJ, CMJ, DJ) plus the unilateral ones. That data is the starting point for all programming. Without it, you’re programming blind.
With Nexo Jump, this full protocol takes less than 15 minutes. Results appear in the app in real time and sync automatically with the coaching software.
Before starting a new block (every 4-6 weeks), repeat the tests to update the baseline and see how the athlete responded to the previous block. That information is the input for designing the next block.
A quick CMJ (without the full protocol) can be used as an acute fatigue indicator at the start of an important session. If the CMJ is more than 5-8% below baseline, it’s a signal to reduce the day’s load.
The closing tests are the objective demonstration of progress. They’re the moment when the data tells the athlete, and the coach, whether the plan worked. With Nexo Kinetics, the comparison between the entry test and the closing test is generated automatically, with a graphical visualization ready to show the athlete.
There are many jump platforms on the market. Most were designed for laboratories or academic research. Nexo Jump was designed for the daily workflow of a personal trainer or S&C coach.
The differences that matter in practice:
That last feature, the integration with the coaching software, is the one no other platform in its category offers. Assessment and programming stop being two separate worlds and become a single workflow.
A jump platform is probably the lowest-cost, highest-return investment you can make as a coach. In less than 15 minutes of assessment, you get data that will inform weeks of programming and differentiate your service from 90% of the personal trainers on the market.
The next step is choosing a platform that doesn’t just measure, but connects that measurement with everything that comes after.
Nexo Jump measures vertical jump, contact time and RSI with millimetre precision — and the software turns that data into programs for your athletes.