A descriptive study of step alignment and foot positioning relative to the tee by professional rugby union goal-kickers

Abstract

This study describes foot positioning during the final two steps of the approach to the ball amongst professional rugby goal-kickers. A 3D optical motion capture system was used to test 15 goal-kickers performing 10 goal-kicks. The distance and direction of each step, as well as individual foot contact positions relative to the tee, were measured. The intra- and inter-subject variability was calculated as well as the correlation (Pearson) between the measurements and participant anthropometrics. Inter-subject variability for the final foot position was lowest (placed 0.03 ± 0.07 m behind and 0.33 ± 0.03 m lateral to the tee) and highest for the penultimate step distance (0.666 ± 0.149 m), performed at an angle of 36.1 ± 8.5° external to the final step. The final step length was 1.523 ± 0.124 m, executed at an external angle of 35.5 ± 7.4° to the target line. The intra-subject variability was very low; distances and angles for the 10 kicks varied per participant by 1.6-3.1 cm and 0.7-1.6°, respectively. The results show that even though the participants had variability in their run-up to the tee, final foot position next to the tee was very similar and consistent. Furthermore, the inter- and intra-subject variability could not be attributed to differences in anthropometry. These findings may be useful as normative reference data for coaching, although further work is required to understand the role of other factors such as approach speed and body alignment.

The epidemiology of kicking injuries in professional Rugby Union: A 15‐season prospective study

“…Given the apparent differences in kick types performed between scrum-halves (ie, box kicks constituting almost 70% of a scrum-half's total kicking load, Figure 3) and the other playing positions who all exhibit higher propensities for kicking injury, it is possible that the mechanics of a box kick are potentially less injurious than other kick types. However, caution must be applied because while the mechanics of goal kicking [30][31][32][33] and punt kicking [34][35][36] have previously been studied in both rugby and Australian Rules Football, direct comparisons between kick type mechanics have not been undertaken and there have been no mechanical descriptions of the other rugby kick types included in the current study. Furthermore, the studies examining goal or punt kicking have focussed on identifying variables which are associated with successful performance, rather than the potential role of kicking mechanics in injury.…”

The biomechanics of place kicking in Rugby Union

“…There was slightly more variation in the antero-posterior (Yaxis) foot placement (mean ± SD = 0.09 ± 0.07 m, Figure 2d); most kickers positioned their support foot CM behind the ball CM (up to a maximum of 0.19 m) although one kicker placed it directly in line and another placed the foot 0.02 m ahead of the ball CM. Support foot placement has previously been shown to be consistent both within and between kickers, particularly when compared with foot placement in the two prior approach steps (Cockcroft & van den Heever, 2016). This relatively low inter-and intra-kicker variation in support foot placement suggests that previous experimental manipulations of 0.30 m in anterior, posterior, and medial directions in rugby place kicking (Baktash al., 2009) may have been excessive and therefore of limited ecological validity.…”

Application of motion capture technology for sport performance analysis (El uso de la tecnología de captura de movimiento para el análisis del rendimiento deportivo)

“…a (Cockcroft & Van Den Heever, 2016) Vicon, 8, 200 Hz 15 Rugby Even though the participants had variability in their run-up to the tee, final foot position next to the tee was very similar and consistent.…”