Coordination of place kicking in Rugby Union.
Degree: PhD, Sport Science, 2020, Stellenbosch University
ENGLISH ABSTRACT: Place kicking is a crucial skill in rugby as more than 40 per cent of the points scored in professional rugby matches are achieved by means of place kicks. Research in rugby kicking has mainly focussed on isolated segment position or movement, with limited literature on segments moving relative to each other. The aim of this study was to identify characteristics of place kicking technique from a coordination and coordination variability perspective.
Ten male kickers performed five trials from three different distances (40 m, 32 m, and 22 m) in a range that proficient kickers should convert successfully 80 per cent of the time. An optoelectronic motion capture system consisting of ten cameras were used for capturing total body kinematic data. Data collection took place outdoor, on a rugby field. Data reductions included normalisation of kicking phases, extracting discrete kinematic variables, joint angles, joint and segment coordination patterns (hip-knee, knee-ankle, and pelvis-torso), and coordination variability measures. ANOVA comparisons were made on discrete data, while statistical parametric mapping repeated measures ANOVA analysis was used for continuous variables to determine differences groups differences. Coordination patterns were determined by means of vector coding technique. A bivariate method of calculating the area of the ellipse at each time point was used to determine the coordination variability. A hierarchal cluster analysis was performed on sagittal plane angles at kicking events to determine different technique profiles. Parameters such as greater hip extension and external rotation during the backswing (p=0.001, p=0.015) as well as increased pelvic external rotation (p=0.015) in the 40 m kicks compared to the 22 m and 32 m kicks are related to the formation of the tension arc in attempt to increase foot speed by means of the stretch-shortening cycle. The 40 m kicks had increase knee flexion (p<0.001), increasing the pre-stretch in the thigh muscles. Both factors allow greater force to be applied to kicking foot over greater distance during forward swing. During the forward swing a period of in-phase is reported as both the hip and the knee were flexing, creating a whip-like action. During the backswing the pelvis and thorax worked together to create a tension arc, while during the forward swing, the anti-phase with pelvis dominancy was seen. The pelvis was main mover for tension arc release, while the thorax stays more stable. Even though absolute changes in joint angles were seen, no changes were reported for the coordination patterns when kicking at different distances (22 m, 32 m, 40 m). An investigation into coordination variability found no differences between groups, indicating no change in movement strategy when kicking at different intensities. The cluster analysis revealed three clusters of sagittal plane kinematics describing a knee-dominant, hip-dominant as well as a combination technique.
Stemming from the above, place kick training can benefit by coaching cues…
Advisors/Committee Members: Venter, Ranel, Cockcroft, John, Preatoni, Ezio, Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science..
Subjects/Keywords: Rugby football – Training; Kicking (Football); Placekickers (Rugby football) – Technique; Rugby Union football players; UCTD; Motor ability; Cluster analysis
to Zotero / EndNote / Reference
APA (6th Edition):
Mathewson, E. (2020). Coordination of place kicking in Rugby Union. (Doctoral Dissertation). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/107778
Chicago Manual of Style (16th Edition):
Mathewson, Elizabeth. “Coordination of place kicking in Rugby Union.” 2020. Doctoral Dissertation, Stellenbosch University. Accessed November 29, 2020.
MLA Handbook (7th Edition):
Mathewson, Elizabeth. “Coordination of place kicking in Rugby Union.” 2020. Web. 29 Nov 2020.
Mathewson E. Coordination of place kicking in Rugby Union. [Internet] [Doctoral dissertation]. Stellenbosch University; 2020. [cited 2020 Nov 29].
Available from: http://hdl.handle.net/10019.1/107778.
Council of Science Editors:
Mathewson E. Coordination of place kicking in Rugby Union. [Doctoral Dissertation]. Stellenbosch University; 2020. Available from: http://hdl.handle.net/10019.1/107778