Change-of-Direction Deficit vs. Deceleration Deficit: A Comparison of Limb Dominance and Inter-limb Asymmetry between Forwards and Backs in Elite Male Rugby Union Players

The aim of this study was to investigate the change of direction (COD) ability and deficits of elite rugby union players, discriminating between position (backs and forwards), and between “faster and slower players”, in multiple COD tasks. Twenty-four male rugby union players from the Brazilian senior National team completed the following assessments: Squat and countermovement jumps; drop jump; standing long jump, horizontal triple jumps; 40-m linear sprint; Pro-agility, L-Drill, and Zig-zag COD tests; and squat 1-repetition maximum. The differences between backs and forwards and between faster and slower performers were examined using magnitude-based inferences. Backs were faster (in both linear and COD speed tests) and jumped higher than forwards. Moreover, they generated an inferior sprint momentum. No differences were found in COD deficit between playing positions. However, when dividing the sample by median split, faster players outperformed their slower counterparts in all power–speed variables and presented higher COD deficits. These results suggest that separating rugby players by playing position might not discriminate players with different COD skills and that the median split analysis is more sensitive to identifying these differences. Furthermore, the present data indicate that faster rugby players are less efficient at changing direction and tolerating higher approach velocities in COD maneuvers.

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Influence of Physical and Technical Aspects on Change of Direction Performance of Rugby Players: An Exploratory Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182413390 ◽

2021 ◽

Vol 18 (24) ◽

pp. 13390

Author(s):

Tomás T. Freitas ◽

Pedro E. Alcaraz ◽

Julio Calleja-González ◽

Ademir F. S. Arruda ◽

Aristide Guerriero ◽

...

Keyword(s):

Knee Flexion ◽

Inertial Sensors ◽

Rugby Union ◽

Lower Body ◽

Kinematic Parameters ◽

Male Athletes ◽

Change Of Direction ◽

National Team ◽

Body Kinematic ◽

Rugby Players

We examined the relationships between change of direction (COD) speed and deficit, and a series of speed- and power-related measurements in national team rugby union players and analyzed the influence of movement patterns on COD ability. Eleven male athletes completed the following physical assessments on different days: day 1—anthropometric measurements, and lower-body kinematic parameters (assessed with eight inertial sensors) and completion time in COD tests (pro-agility, 45° cutting maneuver (CUT), and “L” (L-Drill)); day 2—bilateral and unilateral squat and countermovement jumps, 40 m linear sprint, and bar-power output in the jump squat and half-squat exercises. Pearson’s product–moment correlations were performed to determine the relationships between COD velocities, COD deficits, and the speed–power variables. Differences between players with higher and lower COD deficits were examined using magnitude-based inferences. Results showed that (1) greater sprint momentum was associated with higher COD deficits, particularly in drills with sharper angles and multiple directional changes (L-drill and pro-agility); (2) higher unilateral jump heights were associated with greater COD deficits in the pro-agility and L-drill but not in the CUT; (3) faster athletes were less efficient at changing direction and presented greater trunk and knee flexion angles during COD maneuvers, probably as a consequence of higher inertia.

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The effect of limb dominance on change of direction biomechanics: A systematic review of its importance for injury risk

Physical Therapy in Sport ◽

10.1016/j.ptsp.2019.04.005 ◽

2019 ◽

Vol 37 ◽

pp. 179-189 ◽

Cited By ~ 7

Author(s):

Thomas Dos’Santos ◽

Chris Bishop ◽

Christopher Thomas ◽

Paul Comfort ◽

Paul A. Jones

Keyword(s):

Systematic Review ◽

Injury Risk ◽

Change Of Direction ◽

Limb Dominance

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Levels of Agreement for the Direction of Inter-Limb Asymmetry during Four Simple Change-of-Direction Tests in Young Male Handball Players: A Pilot Study

Symmetry ◽

10.3390/sym13101940 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1940

Author(s):

Žiga Kozinc ◽

Chris Bishop ◽

Jernej Pleša ◽

Nejc Šarabon

Keyword(s):

Pilot Study ◽

Effect Size ◽

Young Male ◽

Trade Off ◽

Change Of Direction ◽

Task Time ◽

Simple Change ◽

Limb Asymmetry ◽

Mean Differences ◽

Standing Start

The purpose of this pilot study was to investigate the effects of change-of-direction (CoD) angle (90° vs. 180°) and the inclusion of acceleration approach on total task time, CoD deficit, and agreement regarding inter-limb asymmetry direction across CoD tasks. The sample included 13 young male handball players (age: 22.4 ± 3.2 years). The CoD tasks were performed over a 10 m distance with 90° and 180° turns. Both CoD tasks were performed under two conditions: (1) from the standing start and, (2) with a 10 m prior acceleration approach. Linear sprint times over a 10 m distance were also recorded for the purpose of determining the CoD deficit. The differences between the outcomes of different test variants were assessed with pairwise t-tests and associated Cohen’s d effect size. The agreement in terms of inter-limb asymmetry direction was assessed descriptively, using percentage of agreement. Results showed that the inclusion of the 10 m approach reduced the total task time (mean differences ranging between 0.26 and 0.35 s; d = 2.27–4.02; p < 0.002). The differences between 90° and 180° turn times were statistically significant under both conditions: (a) without approach (0.44–0.48 s; d = 4.72–4.84; all p < 0.001), and (b) with approach (0.50–0.54 s; d = 4.41–5.03; p < 0.001). The agreement regarding inter-limb asymmetry direction among the tasks was 30.7–61.5%. The differences between the tasks could be explained by the angle–velocity trade-off. The results of this study imply that the CoD tasks should not be used interchangeably when assessing inter-limb asymmetries.

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Time Course of Recovery for Performance Attributes and Circulating Markers of Muscle Damage Following a Rugby Union Match in Amateur Athletes

Sports ◽

10.3390/sports8050064 ◽

2020 ◽

Vol 8 (5) ◽

pp. 64 ◽

Cited By ~ 1

Author(s):

Bruno Victor Corrêa da Silva ◽

Mário Antônio de Moura Simim ◽

Rodrigo Barboza da Silva ◽

Edmar Lacerda Mendes ◽

Bernardo Neme Ide ◽

...

Keyword(s):

Muscle Damage ◽

Time Course ◽

Rugby Union ◽

Test Time ◽

Amateur Athletes ◽

Change Of Direction ◽

Circulating Markers ◽

Time Courses ◽

And Performance ◽

Run Test

Background: We sought to determine the time course of changes in neuromuscular performance and muscle damage following a single rugby union match. Methods: Fourteen male amateur rugby players (28.9 ± 3.5 yrs; 1.7 ± 5.1 m; 86.1 ± 11.1 kg) participated. Plasma activity of creatine kinase ([CK]) and lactate dehydrogenase (LDH), L-run test (change of direction) and 30-m sprint (T30; speed) with 10-m lap time (T10; acceleration) were assessed on six occasions: one week before the match (PRE) and immediately, 24, 48, 72, and 96 h post-match. Results: Relative to PRE, LDH was elevated immediately post-match (+33.6% ± 13.6%; p < 0.001) and [CK] was elevated immediately (+64.1% ± 38.8%, p = 0.001) and 24 h post-match (+352% ± 317%; p = 0.024). L-run test time increased 16.0 ± 8.7% relative to PRE at 24 h post (p < 0.001) and remained elevated through 96 h post-match (p < 0.05). T10 and T30 times increased relative to PRE immediately post-match (+12.0% ± 10.4%, p = 0.008; and +6.1% ± 4.9%; p = 0.006, respectively), though T30 times were similar to baseline by 48 h post-match whereas T10 times remained elevated through 72 h post-match. Conclusions: A single, competitive rugby union match induces significant muscle damage and performance decrements with distinct time courses of recovery in amateur athletes. Notably, change of direction attributes (i.e., L-run) appear to have the longest time course to full recovery.

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Intra- and Inter-Limb Strength Asymmetry in Soccer: A Comparison of Professional and Under-18 Players

Sports ◽

10.3390/sports9090129 ◽

2021 ◽

Vol 9 (9) ◽

pp. 129

Author(s):

Chris Bishop ◽

Giuseppe Coratella ◽

Marco Beato

Keyword(s):

Knee Extensor ◽

Peak Torque ◽

Soccer Players ◽

Knee Extensors ◽

Isokinetic Dynamometer ◽

Percentage Difference ◽

Strength Asymmetry ◽

Limb Asymmetry ◽

Limb Dominance ◽

Anterior Posterior

(1) Background: the present study examined the isokinetic peak torque exerted by both knee extensors and flexors, anterior–posterior imbalance and the magnitude and direction of inter-limb asymmetry in professional and academy soccer players. (2) Methods: one hundred soccer players (professional = 50, elite academy = 50) volunteered to take part in this investigation. An isokinetic dynamometer was used to measure the knee extensor (quadriceps) and flexors muscle (hamstrings) torques of the limbs as well as inter-limb asymmetries—using a standard percentage difference equation. (3) Results: professional players exhibited significantly greater (effect size [ES] = large) strength levels in the quadriceps and hamstrings under both testing conditions, significantly higher (small to moderate) intra-limb ratio values for 60°·s−1 but not for the 300°·s−1 test condition, significantly (small to moderate) lower inter-limb asymmetry values for all test conditions, with the exception of the hamstrings at 60°·s−1 and the direction of asymmetry was poor to slight, indicating that limb dominance was rarely the same between groups. (4) Conclusions: this study shows that isokinetic assessments, i.e., peak torque exerted by both knee extensors and flexors and intra-limb ratio, and the subsequent inter-limb asymmetry, i.e., magnitude and direction, can differentiate between professional and academy soccer players.

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Assessing Inter-Limb Asymmetries in Soccer Players: Magnitude, Direction and Association with Performance

Journal of Human Kinetics ◽

10.2478/hukin-2021-0081 ◽

2021 ◽

Vol 79 (1) ◽

pp. 41-53

Author(s):

Marc Madruga-Parera ◽

Thomas Dos’Santos ◽

Chris Bishop ◽

Anthony Turner ◽

David Blanco ◽

...

Keyword(s):

Body Height ◽

Ankle Dorsiflexion ◽

Soccer Players ◽

Kinetic Chain ◽

Leg Extension ◽

Change Of Direction ◽

Test Specificity ◽

Limb Asymmetry ◽

The Relationship ◽

Skill Change

Abstract In this study, we aimed to analyze the magnitude and direction of inter-limb asymmetries in ankle dorsiflexion range of motion (ROM), power (using iso-inertial devices), and a neuromuscular skill (change of direction). Secondarily, we aimed to determine the relationship between inter-limb asymmetry scores for each test and also between these scores and the scores for the different performance tests. Sixteen semiprofessional male soccer players (age: 25.38 ± 6.08 years; body height: 1.78 ± 0.64 m; body mass: 79.5 ± 14.9 kg) participated in this study. We calculated inter-limb asymmetries using five tests: ankle dorsiflexion ROM, change of direction (COD 180º), and iso-inertial resistance tasks in the open (leg extension strength (LE), leg curl strength (LC)) and closed (crossover step (CRO)) kinetic chain. Our results showed that asymmetry magnitudes differed between all tests with highest inter-limb asymmetries displayed during iso-inertial overloading. In addition, we observed that the direction of asymmetries varied depending on the test-specificity, and that the CRO asymmetries had a negative association with LE and CRO performance. These findings highlight the independent nature of asymmetries and that CRO could be an appropriate test to detect asymmetries related with the performance of soccer-specific actions (such as changes of direction). Practitioners are encouraged to use multiple tests to detect existing inter-limb differences according to the specific characteristics of each sport.

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Video-based perceptual training as a method to improve reactive agility performance in rugby union players

International Journal of Sports Science & Coaching ◽

10.1177/1747954116676106 ◽

2016 ◽

Vol 11 (6) ◽

pp. 799-809

Author(s):

Louise Engelbrecht ◽

Elmarie Terblanche ◽

Karen E Welman

Keyword(s):

Training Group ◽

Rugby Union ◽

Control Group ◽

Training Method ◽

Post Intervention ◽

Perceptual Training ◽

Retention Period ◽

Change Of Direction ◽

Reactive Agility ◽

Alternative Training

This study investigated the effectiveness of rugby-specific video-based perceptual training on the speed and agility of club-level rugby union players. Twenty-six players were randomly divided into either a video-based, field-based or conventional training group. For six weeks, the video-based and field-based groups performed agility training twice a week in addition to their regular rugby training, while the control group was restricted to regular rugby training. Speed, reactive agility and change of direction speed were tested pre- and post-intervention, and after a six-week retention period. Results revealed that both video- and field-based training were almost certainly more beneficial (13% and 17%, respectively) to improve reactive agility compared to conventional rugby training alone. In addition, both intervention groups maintained their reactive agility improvements following the retention period. Consequently, video-based training, likely because of a perceptual component, could be used as an alternative training method to improve reactive agility.

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Validity of a Squash-Specific Test of Change-of-Direction Speed

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.4.2.176 ◽

2009 ◽

Vol 4 (2) ◽

pp. 176-185 ◽

Cited By ~ 17

Author(s):

Michael Wilkinson ◽

Damon Leedale-Brown ◽

Edward M. Winter

Keyword(s):

Field Test ◽

Rugby Union ◽

Specific Test ◽

Talent Identification ◽

Change Of Direction ◽

Association Football ◽

Speed Test ◽

Reliable Tool ◽

Performance Time ◽

Performance Times

Purpose:We examined the validity and reproducibility of a squash-specifc test designed to assess change-of-direction speed.Methods:10 male squash and 10 male association-football and rugby-union players completed the Illinois agility run (IAR) and a squash change-of-direction-speed test (SCODS) on separate days. Tests were repeated after 24 h to assess reproducibility. The best time from three attempts was recorded in each trial.Results:Performance times on the IAR (TE 0.27 s, 1.8%, 90% CI 0.21 to 0.37 s; LOA -0.12 s ± 0.74; LPR slope 1, intercept -2.8) and SCODS (TE 0.18 s, 1.5%, 90% CI 0.14 to 0.24 s; LOA 0.05 s ± 0.49; LPR slope 0.95, intercept 0.5) were reproducible. There were no statistically significant differences in performance time between squash (14.75 ± 0.66 s) and nonsquash players (14.79 ± 0.41 s) on the IAR. Squash players (10.90 ± 0.44 s) outperformed nonsquash players (12.20 ± 0.34 s) on the SCODS (P < .01). Squash player rank significantly correlated with SCODS performance time (Spearman’s ρ = 0.77, P < .01), but not IAR performance time (Spearman’s ρ = 0.43, P = .21).Conclusions:The results suggest that the SCODS test is a better measure of sport-specific capability than an equivalent nonspecific field test and that it is a valid and reliable tool for talent identification and athlete tracking.

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