The effect of physical fatigue on tackling technique in Rugby Union

Objectives: To measure the change in tackling technique of rugby union players following an acute bout of physically fatiguing exercise. Design: Randomised cross-over study design with a physical fatigue condition and no-physical fatigue condition (control). Methods: Nineteen male amateur club rugby union players ( n = 19) and a total of 887 tackles were analysed. During each condition, each player performed four sets of six tackles (three dominant and three non-dominant shoulder) on a contact simulator. Between each set of tackles in the physical fatigue condition, players performed the prolonged high-intensity intermittent running ability test. Using video, player's tackling proficiency for each tackle was measured by awarding either one point or zero points depending on whether a particular technique was performed or not. The sum of these points represents player's tackling proficiency (score out of 9, measured in arbitrary units). Results: In the non-dominant shoulder, a difference between fatigue and control was found at set two (Fatigue 7.3 [7.1-7.6] AU vs. Control 7.6 [7.4-7.9] AU, p = 0.06, ES = 0.3 small) and set three (Fatigue 7.3 [7.0-7.5] AU vs. Control 7.7 [7.5-7.9] AU, p = 0.006, ES = 0.5 small). During the control condition, tackling proficiency scores improved from baseline for non-dominant tackles (Baseline 7.4 [7.2-7.6] AU, vs Set two 7.6 [7.4-7.9] AU, p = 0.08 ES = 0.3 small; vs Set three 7.7 [7.5-7.9] AU, p = 0.05, ES = 0.4 small). Conclusions: In conclusion, this study shows that physical fatigue can potentially affect rugby union players' tackling technique. Therefore, players should develop technical capacity to resist the effects of physical fatigue during the tackle. (C) 2020 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.