Can vertical stiffness derived from accelerometers embedded in GPS units and collected during a sub-maximal yo-yo test be used as a reliable alternative to counter movement jump testing when testing elite youth soccer players’ level of fatigue?

Woodley, Euan (2022) Can vertical stiffness derived from accelerometers embedded in GPS units and collected during a sub-maximal yo-yo test be used as a reliable alternative to counter movement jump testing when testing elite youth soccer players’ level of fatigue? MSc(R) thesis, University of Glasgow.

Abstract

This study aimed to discover whether vertical stiffness (Kvert), recorded via accelerometers embedded within Global Positioning System (GPS) units, could be used to monitor the level of neuromuscular fatigue for elite youth soccer players. 17 male outfield soccer players (age: 18.4 ± 1.1years; height: 179.8 ± 6cm; weight: 74.7 ± 6.5kg) took part in the study. Testing took place on match day (MD)-1 and MD+2, and GPS units were worn during matches. The testing consisted of 3 maximum effort counter movement jumps (CMJ), with the highest jump being analysed, and a submaximal Yo- Yo Intermittent Recovery Test Level 1 which lasted for 6 minutes. Flight time:contraction time (FT:CT) was recorded from the CMJs, and Kvert was recorded from the Yo-Yo test using the sine wave method via the software Athletic Data Innovations (ADI). It was discovered that there was no significant change (p > 0.05) in Kvert from MD-1 to MD+ 2 (31.75 ± 7.09kN/m and 31.23 ± 6.38kN/m) for players that played >60 minutes in matches. There was no correlation (p > 0.05) between the change from match to match for any GPS match variable and the change in Kvert from MD-1 to MD+2 for players that played >60 minutes. The only significant change was found for players playing <60 minutes in matches, with a significant decrease (p < 0.05) for FT:CT between MD-1 and MD+2 (0.8 ± 0.13 and 0.75 ± 0.13, Cohen’s D effect size = 0.4). The small sample size of the study results in an increased risk of type 1 and type 2 errors however, meaning that this statistically significant difference is possibly due to an error. Power calculations were performed on the data collected, with it being clear that a far larger sample size would be required for reliance to be placed on the statistical results. Due to the limitations of the study and results from previous studies such as from Morin and colleagues in 2006 and Girard and colleagues in 2011 and 2010 which discovered Kvert is affected by level of fatigue, I believe further research is warranted due to the potential of using Kvert to monitor neuromuscular fatigue of large groups of players simultaneously. It is however recommended that further research focuses on obtaining Kvert in another method than during the 6-minute Yo-Yo test, due to the significant load this places on a squad of players over the course of a season if performed multiple times per week.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Scobie, Mr. Nairn and Kemi, Dr. Ole
• Date of Award: 2022
• Depositing User: Theses Team
• Unique ID: glathesis:2022-82848
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 May 2022 13:50
• Last Modified: 05 May 2022 13:50
• Thesis DOI: 10.5525/gla.thesis.82848
• URI: https://theses.gla.ac.uk/id/eprint/82848