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Biomechanical symmetry in elite rugby union players during dynamic tasks: an investigation using discrete and continuous data analysis techniques.

Marshall B, Franklyn-Miller A, Moran K, King E, Richter C, Gore S, Strike S, Falvey É - BMC Sports Sci Med Rehabil (2015)

Bottom Line: The majority of variables were found to be symmetrical with a total of 57/60 variables displaying symmetry in the discrete point analysis and 55/60 in the ACP.The five variables that were found to be asymmetrical were hip abductor moment in the drop landing (p = 0.02), pelvis lift/drop in the drop landing (p = 0.04) and hurdle hop (p = 0.02), ankle internal rotation moment in the cut (p = 0.04) and ankle dorsiflexion angle also in the cut (p = 0.01).When examining symmetry it is recommended to incorporate continuous data analysis techniques rather than a discrete point analysis alone; a discrete point analysis was unable to detect two of the five asymmetries identified.

View Article: PubMed Central - PubMed

Affiliation: Sports Medicine Department, Sports Surgery Clinic, Santry Demesne, Dublin, Ireland ; School of Health and Human Performance, Dublin City University, Dublin, Ireland ; Insight Centre for Data Analytics, Dublin City University, Dublin, Ireland.

ABSTRACT

Background: While measures of asymmetry may provide a means of identifying individuals predisposed to injury, normative asymmetry values for challenging sport specific movements in elite athletes are currently lacking in the literature. In addition, previous studies have typically investigated symmetry using discrete point analyses alone. This study examined biomechanical symmetry in elite rugby union players using both discrete point and continuous data analysis techniques.

Methods: Twenty elite injury free international rugby union players (mean ± SD: age 20.4 ± 1.0 years; height 1.86 ± 0.08 m; mass 98.4 ± 9.9 kg) underwent biomechanical assessment. A single leg drop landing, a single leg hurdle hop, and a running cut were analysed. Peak joint angles and moments were examined in the discrete point analysis while analysis of characterising phases (ACP) techniques were used to examine the continuous data. Dominant side was compared to non-dominant side using dependent t-tests for normally distributed data or Wilcoxon signed-rank test for non-normally distributed data. The significance level was set at α = 0.05.

Results: The majority of variables were found to be symmetrical with a total of 57/60 variables displaying symmetry in the discrete point analysis and 55/60 in the ACP. The five variables that were found to be asymmetrical were hip abductor moment in the drop landing (p = 0.02), pelvis lift/drop in the drop landing (p = 0.04) and hurdle hop (p = 0.02), ankle internal rotation moment in the cut (p = 0.04) and ankle dorsiflexion angle also in the cut (p = 0.01). The ACP identified two additional asymmetries not identified in the discrete point analysis.

Conclusions: Elite injury free rugby union players tended to exhibit bi-lateral symmetry across a range of biomechanical variables in a drop landing, hurdle hop and cut. This study provides useful normative values for inter-limb symmetry in these movement tests. When examining symmetry it is recommended to incorporate continuous data analysis techniques rather than a discrete point analysis alone; a discrete point analysis was unable to detect two of the five asymmetries identified.

No MeSH data available.


Related in: MedlinePlus

Layout for a right footed plant and cut left. From a standing start participants sprinted maximally toward a marker placed on the floor, made a single complete foot contact on the force plate, and performed a 75° cut before sprinting maximally to the finish
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Fig1: Layout for a right footed plant and cut left. From a standing start participants sprinted maximally toward a marker placed on the floor, made a single complete foot contact on the force plate, and performed a 75° cut before sprinting maximally to the finish

Mentions: The drop landing was initiated from a 30 cm step where participants stood upright with their hands across their chest and their non-weight bearing foot behind with an approximate 90° knee bend. They then dropped off the step, made a uni-lateral landing on the force platform and held the landing position for 2 s [30]. An additional movie file shows this in more detail [see Additional file 1]. Participants were instructed to drop directly from the 30 cm height rather than jump vertically. The hurdle hop consisted of a lateral hop over a 15 cm hurdle and an immediate hop back to the initial starting position. The distance between foot contacts was approximately 40 cm; the distance between force plate centres. Participants undertook the hop as quickly as possible, and while the free leg was in the same orientation as described for the drop landing, the arms were free to move [see Additional file 2]. The landing from the first hop over the hurdle was analysed. For the cut, participants ran as fast as possible toward a marker placed on the floor, made a single complete foot contact on the force plate, and performed a 75° cut before running maximally to the finish (Fig. 1). An additional movie file shows the cut in greater detail [see Additional file 3]. Time to complete the cut was recorded using the Hotspot timing system (Games Education - Hotspot, UK).Fig. 1


Biomechanical symmetry in elite rugby union players during dynamic tasks: an investigation using discrete and continuous data analysis techniques.

Marshall B, Franklyn-Miller A, Moran K, King E, Richter C, Gore S, Strike S, Falvey É - BMC Sports Sci Med Rehabil (2015)

Layout for a right footed plant and cut left. From a standing start participants sprinted maximally toward a marker placed on the floor, made a single complete foot contact on the force plate, and performed a 75° cut before sprinting maximally to the finish
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4940714&req=5

Fig1: Layout for a right footed plant and cut left. From a standing start participants sprinted maximally toward a marker placed on the floor, made a single complete foot contact on the force plate, and performed a 75° cut before sprinting maximally to the finish
Mentions: The drop landing was initiated from a 30 cm step where participants stood upright with their hands across their chest and their non-weight bearing foot behind with an approximate 90° knee bend. They then dropped off the step, made a uni-lateral landing on the force platform and held the landing position for 2 s [30]. An additional movie file shows this in more detail [see Additional file 1]. Participants were instructed to drop directly from the 30 cm height rather than jump vertically. The hurdle hop consisted of a lateral hop over a 15 cm hurdle and an immediate hop back to the initial starting position. The distance between foot contacts was approximately 40 cm; the distance between force plate centres. Participants undertook the hop as quickly as possible, and while the free leg was in the same orientation as described for the drop landing, the arms were free to move [see Additional file 2]. The landing from the first hop over the hurdle was analysed. For the cut, participants ran as fast as possible toward a marker placed on the floor, made a single complete foot contact on the force plate, and performed a 75° cut before running maximally to the finish (Fig. 1). An additional movie file shows the cut in greater detail [see Additional file 3]. Time to complete the cut was recorded using the Hotspot timing system (Games Education - Hotspot, UK).Fig. 1

Bottom Line: The majority of variables were found to be symmetrical with a total of 57/60 variables displaying symmetry in the discrete point analysis and 55/60 in the ACP.The five variables that were found to be asymmetrical were hip abductor moment in the drop landing (p = 0.02), pelvis lift/drop in the drop landing (p = 0.04) and hurdle hop (p = 0.02), ankle internal rotation moment in the cut (p = 0.04) and ankle dorsiflexion angle also in the cut (p = 0.01).When examining symmetry it is recommended to incorporate continuous data analysis techniques rather than a discrete point analysis alone; a discrete point analysis was unable to detect two of the five asymmetries identified.

View Article: PubMed Central - PubMed

Affiliation: Sports Medicine Department, Sports Surgery Clinic, Santry Demesne, Dublin, Ireland ; School of Health and Human Performance, Dublin City University, Dublin, Ireland ; Insight Centre for Data Analytics, Dublin City University, Dublin, Ireland.

ABSTRACT

Background: While measures of asymmetry may provide a means of identifying individuals predisposed to injury, normative asymmetry values for challenging sport specific movements in elite athletes are currently lacking in the literature. In addition, previous studies have typically investigated symmetry using discrete point analyses alone. This study examined biomechanical symmetry in elite rugby union players using both discrete point and continuous data analysis techniques.

Methods: Twenty elite injury free international rugby union players (mean ± SD: age 20.4 ± 1.0 years; height 1.86 ± 0.08 m; mass 98.4 ± 9.9 kg) underwent biomechanical assessment. A single leg drop landing, a single leg hurdle hop, and a running cut were analysed. Peak joint angles and moments were examined in the discrete point analysis while analysis of characterising phases (ACP) techniques were used to examine the continuous data. Dominant side was compared to non-dominant side using dependent t-tests for normally distributed data or Wilcoxon signed-rank test for non-normally distributed data. The significance level was set at α = 0.05.

Results: The majority of variables were found to be symmetrical with a total of 57/60 variables displaying symmetry in the discrete point analysis and 55/60 in the ACP. The five variables that were found to be asymmetrical were hip abductor moment in the drop landing (p = 0.02), pelvis lift/drop in the drop landing (p = 0.04) and hurdle hop (p = 0.02), ankle internal rotation moment in the cut (p = 0.04) and ankle dorsiflexion angle also in the cut (p = 0.01). The ACP identified two additional asymmetries not identified in the discrete point analysis.

Conclusions: Elite injury free rugby union players tended to exhibit bi-lateral symmetry across a range of biomechanical variables in a drop landing, hurdle hop and cut. This study provides useful normative values for inter-limb symmetry in these movement tests. When examining symmetry it is recommended to incorporate continuous data analysis techniques rather than a discrete point analysis alone; a discrete point analysis was unable to detect two of the five asymmetries identified.

No MeSH data available.


Related in: MedlinePlus