Match high-speed running distances are often suppressed after return from hamstring strain injury in professional footballers
- Authors: Whiteley, Rodney , Massey, Andrew , Gabbett, Tim , Blanch, Peter , Cameron, Matthew , Conlan, Greta , Ford, Matthew , Williams, Morgan
- Date: 2021
- Type: Text , Journal article
- Relation: Sports Health Vol. 13, no. 3 (2021), p. 290-295
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- Description: Background: High-speed running is commonly implicated in the genesis of hamstring injury. The success of hamstring injury management is typically quantified by the duration of time loss or reinjury rate. These metrics do not consider any loss in performance after returning to play from hamstring injury. It is not known to what extent high-speed running is altered on return to play after such injury. Hypothesis: Match high-speed running distance will change after returning from hamstring injury. Study Design: Non-randomized cohort. Level of Evidence: Level 3. Methods: Match high-speed running distance in highest level professional football (soccer, Rugby League, Rugby Union, and Australian Rules) were examined for a minimum of 5 games prior and subsequent to hamstring strain injury for individual differences using a linear regression models approach. A total of 22 injuries in 15 players were available for analysis. Results: Preinjury cumulative high-speed running distances were strongly correlated for each individual (r2 = 0.92-1.0 P < 0.0001). Pre- and postinjury high-speed running data were available for a median of 15 matches (range, 6-15). Variance from the preinjury high-speed running distance was significantly less (P = 0.0005) than the post injury values suggesting a suppression of high-speed running distance after returning from injury. On return to play, 7 of the 15 players showed a sustained absolute reduction in preinjury high-speed running distance, 7 showed no change, and 1 player (only) showed an increase. Analysis of subsequent (second and third injury) return to play showed no differences to return from the index injury. Conclusion: Return to play was not associated with return to high-speed running performance for nearly half of the players examined, although the same number showed no difference. Persisting deficits in match high-speed running may exist for many players after hamstring strain injury. Clinical Relevance: Returning to play does not mean returning to (high-speed running) performance for nearly half of the high-level professional football players examined in this study. This suggests that successful return to play metrics should be expanded from simple time taken and recurrence to include performance.
Are the perceptual and design-making components of agility trainable? A preliminary investigation
- Authors: Serpell, Benjamin , Young, Warren , Ford, Matthew
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 25, no. 5 (2011), p. 1240-1248
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- Description: Are the perceptual and decision-making components of agility trainable? A preliminary investigation. J Strength Cond Res 25(5): 1240-1248, 2011-Agility is an open motor skill; requiring change of direction speed (CODS) and perceptual and decision-making ability. The aim of this study was to determine whether the perceptual and decision-making component of agility can be trained. Fifteen rugby league players were tested on a sport-specific reactive agility test (RAT) and a CODS test. Players were then allocated to a training group (n = 8) or a nontraining group (n = 7). The training group underwent 3 weeks of reactive agility training that was designed to enhance perceptual and decision-making ability. After 3 weeks, all players were tested again. The training group's mean reactive agility time was 1.92 +/- 0.17 seconds preintervention and 1.66 +/- 0.14 seconds postintervention. The nontraining group's mean reactive agility time was 1.89 +/- 0.16 and 1.87 +/- 0.15 seconds, respectively. Mean CODS time for the training group was 1.64 +/- 0.15 seconds preintervention and 1.66 +/- 0.14 seconds postintervention. The nontraining group's mean CODS time was 1.61 +/- 0.12 and 1.62 +/- 0.12 seconds. Mean perception and response time for the training group, measured on the RAT, was 0.33 +/- 0.33 seconds preintervention and 0.04 +/- 0.22 seconds postintervention. The nontraining group's values were 0.34 +/- 0.20 and 0.27 +/- 0.28 seconds, respectively (results are +/-sigma). Differences in mean reactive agility time and perception and response time from pre to postintervention for the training group were statistically significant, as were differences in those values between the training and nontraining group post intervention. All other comparisons were not. Results from this study suggest that the perceptual and decision-making components of agility are trainable. Coaches should incorporate some open motor skills training in their programs when training agility.
The development of a new test of agility for rugby league
- Authors: Serpell, Benjamin , Ford, Matthew , Young, Warren
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of strength and conditioning research Vol. 24, no. 12 (2010), p. 3270-3277
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- Description: The development of a new test of agility for rugby league. J Strength Cond Res 24(12): 3270-3277, 2010-Agility requires change of direction speed (CODS) and also perceptual and decision-making skills and reaction speed. The purpose of this study was to develop a reliable and valid agility test for rugby league, which stressed all those dimensions. Players from a subelite rugby league team were tested twice on a sport-specific reactive agility test (RAT) and CODS test. Data were analyzed for reliability. For validity results from the subelite groups, first test was compared with data from an elite group. The RAT required participants to run toward an unpredictable life-size video of an attacking opponent and react to that video by changing direction. The CODS test required the same movement patterns however direction changes were preplanned. The subelite group's mean time to complete the CODS test and RAT on their first test was 1.67 +/- 0.15 and 1.98 +/- 0.16 seconds, respectively, and 1.62 +/- 0.14 and 1.91 +/- 0.17 seconds, respectively, on their second test (results are +/- sigma). Statistical analyses revealed no significant difference in means (p < 0.05) and good correlation (intraclass correlation coefficient = 0.87 and 0.82, respectively). The elite group's mean time to complete the tests was 1.65 +/- 0.09 and 1.79 +/- 0.12 seconds, respectively. Statistical analyses revealed a significant difference in mean RAT time between the elite group and the subelite group (p < 0.05). The RAT was reliable and valid. Performance differences on the RAT were attributed to differences in perceptual skills and/or reaction ability. Testing and training agility should therefore stress those dimensions of agility and not just CODS.