%0 Journal Article
%T Assessment of the accuracy of different systems for measuring football velocity and spin rate in the field
%A Katrine Okholm Kryger
%A Steph Forrester
%A S¨¦an Mitchell
%J Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
%@ 1754-338X
%D 2019
%R 10.1177/1754337119830249
%X The aim of this study was to measure the level of agreement of four portable football velocity and spin rate measurement systems (Jugs speed radar gun, 2-D high-speed video, TrackMan and adidas miCoach football) against a Vicon motion analysis system. One skilled male university football player performed 70 shots covering a wide range of ball velocities (12¨C30£¿m£¿s£¿1) and spin rates (94¨C743£¿r/min). A Bland¨CAltman analysis was used to assess the level of agreement. For ball velocity, the 2-D high-speed video had the smallest systematic error, followed by the radar gun, TrackMan and miCoach football at 0.2, 0.4, 0.5 and 4.8£¿m£¿s£¿1, respectively. A similar ranking was also observed for the random errors (95% confidence intervals: ¡À0.4, ¡À1.5, ¡À1.9 and ¡À6.0£¿m£¿s£¿1). The first three systems all tracked ball velocity in >90% of shots, while the miCoach football tracked slightly fewer shots (79%). For spin rate, the miCoach football had a much smaller systematic error (4 vs 38£¿r/min) and random error (95% confidence intervals: ¡À24 vs ¡À355£¿r/min) compared to TrackMan. The miCoach also successfully tracked spin rate in more shots than the TrackMan (79% vs 44%). These results indicate that 2-D high-speed video would be the preferred option for the field assessment of ball velocity; however, radar gun and TrackMan may also be appropriate. A minimum of 10 frames of 2-D high-speed video, captured close to the ball starting position, was demonstrated to be sufficient in providing a reliable measure of ball velocity. The miCoach ball is the preferred option for field assessment of ball spin rate
%K Soccer
%K speed
%K miCoach
%K TrackMan
%K radar gun
%K high-speed video
%K spin rate
%K velocity
%U https://journals.sagepub.com/doi/full/10.1177/1754337119830249