The agreement between bushnell and stalker radar guns for measuring ball speed in throwing and kicking

Abstract

This study aimed to compare the agreement of ball speed in throwing and kicking between the Bushnell and the Stalker radar guns. Sixty-four healthy young adults (21.8 ± 3.5 years) performed a total of 320 throws and 320 kicks during the study. Ball speed was measured using both the Bushnell and the Stalker radar guns for each trial. The mean difference in throwing speeds was found to be 1.39 km/h (95% CI: 1.20; 1.59), while the mean difference in kicking speeds was 1.38 km/h (95% CI: 1.20; 1.56). The agreement, assessed through intraclass correlation tests, revealed an excellent level of consistency for both ball speeds in throwing (ICC: 0.989 [95% CI: 0.986; 0.991]) and kicking (ICC: 0.986 [95% CI: 0.983; 0.989]). An analysis of variance showed significant differences for both throwing (p < 0.001; d = 0.799) and kicking (p < 0.001; d = 0.851), accompanied by a percentage difference of 2.17% in throwing and 1.91% in kicking. In conclusion, this study suggests that the correlation between both radar guns is excellent. However, Bushnell consistently underestimates the ball speeds of throws and kicks, with differences that are statistically significant and practically relevant. Despite this, the high correlation between the devices indicates that practitioners can use either device, provided they adjust normative values accordingly.