AUTHOR=Bursais Abdulmalek K. , Gentles Jeremy A. , Albujulaya Naif M. , Stone Michael H. 

TITLE=Field based assessment of a tri-axial accelerometers validity to identify steps and reliability to quantify external load

JOURNAL=Frontiers in Physiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.942954

DOI=10.3389/fphys.2022.942954

ISSN=1664-042X

ABSTRACT=Background: The monitoring of accelerometry derived load has received increased attention in recent years. However, the ability of such measures to quantify training load during sport-related activities is not well established. Thus, the current study aimed to assess the validity and reliability of tri-axial accelerometers to identify steps and quantify external load during several locomotor conditions including walking, running, and sprinting. Method: Thirty physically active college students (height = 176.8 ± 6.1cm, weight = 82.3 ± 12.8kg) participated. Acceleration data was collected via two tri-axial accelerometers (Device A and B) sampling at 100Hz, mounted closely together at the xiphoid process. Each participant completed two trials of straight-line walking, running, and sprinting on a 20m course. Device A was used to assess accelerometer validity to identify steps and the test-retest reliability of the instrument to quantify the external load. Device A and Device B were used to assess inter-device reliability. The reliability of accelerometry-derived metrics Impulse Load (IL) and Magnitude g (MAG) were assessed. Results: The instrument demonstrated a positive predictive value (PPV) of 96.98-99.41% and an agreement of 93.08-96.29% for step detection during all conditions. Good test-retest reliability was found with a coefficient of variation (CV) < 5% for IL and MAG during all locomotor conditions. Good inter-device reliability was also found for all locomotor conditions (IL and MAG CV < 5%). Conclusion: This research indicates that tri-axial accelerometers can be used to identify steps and quantify external load when movement is completed at a range of speeds.