Comprehensive data collection and accuracy as a guiding principle are at the core of our work at Sportlight. That’s why we’re excited to share the results of a recent validation study of the Sportlight system, published in Sports Engineering journal.
First, what is Sportlight? Our movement-tracking LiDAR-based system uses infrared lasers to measure distances between a given target and a sensor, then calculates the time it takes to reach, reflect and return from the target. Although this study collected only soccer-specific movement data, Sportlight is capable of recording variable-distances player velocity and acceleration at high levels of accuracy – an application that can be leveraged across sports.
Entitled “Validation of a LiDAR‐based player tracking system during football‐specific tasks,” the study essentially sought to answer a simple question: How accurate is the Sportlight system? Performance evaluators and sports executives will be interested to hear the answer.
How the Study Was Conducted
The study, authored by Theodoros M. Bampouras and Neil M. Thomas (whose areas of expertise lie in research methods and biomechanics), sought to validate the efficacy of Sportlight’s LiDAR-based system against the gold standard in the field – a 64-camera 3D motion capture system (MoCap).
As the study describes the Sportlight system: “Multiple units provide greater coverage, but measurements can take place with one unit, as each one is claimed to be capable of tracking players independently to the other units. Proprietary software then directly uses the unfiltered velocity and acceleration data to provide player relevant metrics to the user.”
Movement data was simultaneously collected by the and MoCap (64 cameras) and Sportlight (four units) systems: Two competitive soccer players, both 18 years old and similarly built and experienced, completed nine trials each of six soccer-specific movements – including straight-line sprints, cuts and curved runs – with three minutes of rest between repetitions. Each of the 18 samples from the trials were treated as subjects, allowing repetition to “enable the assessment of the agreement of the relevant variables.” Essentially, this approach helped remove noise and statistical chance from the data outcomes.
Data collected by the Sportlight system compared favorably to that of the MoCap system (as well as other legacy systems involved in the study for comparative purposes). Error values were found to be statistically insignificant when compared to the gold-standard technology:
“Our results showed that LiDAR velocity and acceleration values, obtained during football-specific movements, are in close agreement with those from the MoCap system, indicating LiDAR provided valid measures of velocity and acceleration in football-specific tasks.”
At the same time, the study identified a distinct Sportlight advantage:
“The present [Sportlight] results are very similar to those of the fixed optical tracking system. This is an important finding, since many professionals working in team sports are often interested in quantifying work done, based on velocity or acceleration KPI thresholds in an attempt to design their training and conditioning programmes, monitor players’ exercise volume and decrease injury risk.”
And because moving and calibrating fixed systems is labor-intensive and potentially introduces error into data outcomes, “teams [utilizing] multiple tracking systems that are not interchangeable … [impair] the use of such data for monitoring purposes. Therefore, the LiDAR-based system can be considered favorably in this context.”
A few important final thoughts about the Sportlight study, pulled directly from the pages of Sports Engineering journal:
“The present data suggest that the LiDAR-based system provides valid measures of velocity, acceleration and time spent within given KPI bands for individual football-specific movements.”
“It provides a continuous measure of distance from the unit without requiring calibration or placement at known distances, thus increasing its usability by practitioners.”
“Practitioners and coaches that want to examine those metrics can therefore confidently use the LiDAR system to obtain them, while not needing to trade off between portability and accuracy.”
In the simplest terms, a peer-reviewed validation study found that Sportlight provided gold-standard movement-tracking accuracy combined with the portability to make the system practical for quantifiable data collection and analysis in the professional sports space.