Original Research ARTICLE
Normal variability of weekly musculoskeletal screening scores and the influence of training load across an Australian Football League season
- 1Institute of Sport, Exercise and Active Living, Victoria University, Australia
- 2Norwegian Defence Institute, Norway
Aim: The sit and reach test (S&R), dorsiflexion lunge test (DLT), and adductor squeeze test (AST) are commonly used in weekly musculoskeletal screening for athlete monitoring and injury prevention purposes. The aim of this study was to determine the normal week to week variability of the test scores, individual differences in variability, and the effects of training load on the scores. Methods: Forty-four elite Australian rules footballers from one club completed the weekly screening tests on day two or three post-main training (pre-season) or post-match (in-season) over a 10 month season. Ratings of perceived exertion and session duration for all training sessions were used to derive various measures of training load via both simple summations and exponentially weighted moving averages. Data were analysed via linear and quadratic mixed modelling and interpreted using magnitude-based inference. Results: Substantial small to moderate variability was found for the tests at both season phases; for example over the in-season, the normal variability ±90% confidence limits were as follows: S&R ±1.01 cm, ±0.12; DLT ±0.48 cm, ±0.06; AST ±7.4%, ±0.6%. Small individual differences in variability existed for the S&R and AST(factor standard deviations between 1.31 and 1.66). All measures of training load had trivial effects on the screening scores. Conclusion: A change in a test score larger than the normal variability is required to be considered a true change. Athlete monitoring and flagging systems need to account for the individual differences in variability. The tests are not sensitive to internal training load when conducted two or three days post-training or post-match, and the scores should be interpreted cautiously when used as measures of recovery.
Keywords: injury prevention, athlete monitoring, Recovery, modelling, hamstring, Groin, calf
Received: 26 Apr 2017;
Accepted: 12 Feb 2018.
Edited by:Gregoire P. Millet, University of Lausanne, Switzerland
Reviewed by:Pascal EDOUARD, University Hospital of Saint-Etienne, France
François Fourchet, Hôpital de la Tour, Switzerland
Copyright: © 2018 Esmaeili, Stewart, Hopkins, Elias, Lazarus, Rowell and Aughey. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Rob J. Aughey, AUGHEY., Victoria University, Institute of Sport, Exercise and Active Living, PO BOX 14428, MCMC, Melbourne, 8001, Victoria, Australia, email@example.com