Quantifying the Physical Demands of Collision Sports: Does Microsensor Technology Measure What It Claims to Measure?

Gabbett T.J.

Objective: This study aimed to evaluate the validity of wearable microsensor technology, particularly global positioning system (GPS) units, in quantifying the physical demands of collision sports, such as rugby league, rugby union, and American football, by automatically detecting collisions.

Background: The physical demands of collision sports are primarily influenced by the large number of collisions players experience during match play. While video recordings have traditionally been used to manually code collisions, wearable microsensor technology has been developed to automate this process, aiming to quantify the physical demands more efficiently.

Methodology: The study compared the performance of two different microtechnology units: GPSports and minimaxX by Catapult Sports. GPSports units were previously found to have significant differences in recorded impacts compared to video-coded collisions. In contrast, minimaxX units, equipped with GPS, triaxial accelerometers, gyroscope, and magnetometer, were tested for their ability to accurately detect collisions. The number and intensity of collisions detected by minimaxX were compared with video-coded collisions.

Results: The minimaxX units demonstrated no significant differences in the number of mild, moderate, and heavy collisions compared to those coded from video recordings. Additionally, a strong correlation (r = 0.96, p < 0.01) was observed between collisions recorded by minimaxX units and those coded from video recordings. Conclusion: The study concluded that minimaxX units can be considered a valid method for quantifying the contact loads typical in collision sports. However, caution should be exercised with other microtechnology units until similar validation research is completed. Sports scientists should be cautious in relying on microsensor technology for quantifying collision loads without proper validation.