Initial ball flight characteristics of curve and instep kicks were investigated. Fifteen international female footballers performed curve and instep kicks from a distance of 20 m from goal and at a 1 m2 target. Seventeen Vicon cameras tracked three-dimensional coordinates of four reflective markers adhered to the ball. Ball flight characteristics were quantified, and the coordinates of the ball relative to the target center were recorded. The lateral launch angle and the angle of the spin axis relative to the horizontal best predicted the horizontal placement of the ball relative to the target. The vertical launch angle, antero-posterior velocity and amount of backspin best predicted the vertical coordinate. Regression models demonstrated how carefully controlled the flight characteristics must be with launch angles constrained within 3° to hit the target. Curve kicks were characterized by significantly greater lateral and vertical launch angles, increased sidespin and spin about the antero-posterior axis, and a more vertical spin axis. This information is beneficial for coaches in training players to achieve the characteristics required to score a goal and avoid a defensive wall. For example, if players consistently kick above or below the target, these findings identify the variables that will help rectify that error.
Alison Alcock, Wendy Gilleard, Nick A.T. Brown, John Baker and Adam Hunter
Simon A. Rogers, Peter Hassmén, Alexandra H. Roberts, Alison Alcock, Wendy L. Gilleard and John S. Warmenhoven
Purpose: A novel 4-task Athlete Introductory Movement Screen was developed and tested to provide an appropriate and reliable movement screening tool for youth sport practitioners. Methods: The overhead squat, lunge, push-up, and a prone brace with shoulder touches were selected based on previous assessments. A total of 28 mixed-sport junior athletes (18 boys and 10 girls; mean age = 15.7 [1.8] y) completed screening after viewing standardized demonstration videos. Athletes were filmed performing 8 repetitions of each task and assessed retrospectively by 2 independent raters using a 3-point scale. The primary rater reassessed the footage 3 weeks later. A subgroup (n = 11) repeated the screening 7 days later, and a further 8 athletes were reassessed 6 months later. Intraclass correlation coefficients (ICC), typical error (TE), coefficient of variation (CV%), and weighted kappa (k) were used in reliability analysis. Results: For the Athlete Introductory Movement Screen 4-task sum score, intrarater reliability was high (ICC = .97; CV = 2.8%), whereas interrater reliability was good (intraclass correlation coefficient = .88; CV = 5.6%). There was a range of agreement from fair to almost perfect (k = .31–.89) between raters across individual movements. A 7-day and 6-month test–retest held good reliability and acceptable CVs (≤ 10%) for sum scores. Conclusion: The 4-task Athlete Introductory Movement Screen appears to be a reliable tool for profiling emerging athletes. Reliability was strongest within the same rater; it was lower, yet acceptable, between 2 raters. Scores can provide an overview of appropriate movement competencies, helping practitioners assess training interventions in the athlete development pathway.