Validity and reliability of an accelerometer-based player tracking device

Abstract

This study aimed to determine the intra- and inter-device accuracy and reliability of wearable athletic tracking devices, under controlled laboratory conditions. A total of nineteen portable accelerometers (Catapult OptimEye S5) were mounted to an aluminum bracket, bolted directly to an Unholtz Dickie 20K electrodynamic shaker table, and subjected to a series of oscillations in each of three orthogonal directions (front-back, side to side, and up-down), at four levels of peak acceleration (0.1g, 0.5g, 1.0g, and 3.0g), each repeated five times resulting in a total of 60 tests per unit, for a total of 1140 records. Data from each accelerometer was recorded at a sampling frequency of 100Hz. Peak accelerations recorded by the devices, Catapult PlayerLoad™, and calculated player load (using Catapult’s Cartesian formula) were used for the analysis. The devices demonstrated excellent intradevice reliability and mixed interdevice reliability. Differences were found between devices for mean peak accelerations and PlayerLoad™ for each direction and level of acceleration. Interdevice effect sizes ranged from a mean of 0.54 (95% CI: 0.34–0.74) (small) to 1.20 (95% CI: 1.08–1.30) (large) and ICCs ranged from 0.77 (95% CI: 0.62–0.89) (very large) to 1.0 (95% CI: 0.99–1.0) (nearly perfect) depending upon the magnitude and direction of the applied motion. When compared to the player load determined using the Cartesian formula, the Catapult reported PlayerLoad™ was consistently lower by approximately 15%. These results emphasize the need for industry wide standards in reporting validity, reliability and the magnitude of measurement errors. It is recommended that device reliability and accuracy are periodically quantified.

The Physiological, Physical, and Biomechanical Demands of Walking Football: Implications for Exercise Prescription and Future Research in Older Adults

“…This device was positioned along the thoracic spine and stabilised within a neoprene vest (Catapult Innovations, Scoresby, Australia) to limit movement. Where possible, participants maintained the use of the same device throughout sessions, as intra-device has demonstrated excellent reliability (CV = 0.01% to <3.0%) (Nicolella, Torres-Ronda, Saylor, & Schelling, 2018). However, because the number of participants was greater than the number of devices, the device retention rate for participants was 84.0 ± 13.3% across all applicable sessions.…”

Positioning and displacement patterns of young players during 5v5, 7v7, 9v9, and 11v11 soccer matches

“…The GPS was placed on the upper back of the player (using an appropriate harness). The reliability of similar type of devices has been well documented in the literature VOLUME --| ISSUE -| 2019 | 5 (Nicolella, Torres-Ronda, Saylor, & Schelling, 2018;Silva et al, 2016;Silva et al, 2015). Each game format was calibrated with the coordinates of four GPS devices stationed in each corner of the pitch for approximately 4 min.…”

A Comparison of a Smartphone App with Other GPS Tracking Type Devices Employed in Football

“…There are challenges when conducting in depth analysis of commercial products in any area and GPS tracker devices are no different and whilst it is understandable that each varies their product to individualise in attempts to gain increase sales, for any researcher it is difficult especially as is in the present study where some metrics were not accessible (Table 2) and this has been reported in reviews of the literature [4,52,53]. This has caused much controversy in establishing reliability and validity in the use of GPS tracking devices in sport with both early studies [30] and more recent studies [54] continuing to highlight the need to set industry wide standards for the use in sport. Having the ability to easily monitor physical activity enables more people, some who maybe Fans of football to better connect to what their idols are doing and increase motivation to engage in physical activity related to football [55,56].…”