Table 1.

Ball-head impact exposure based on sex and age.

	Total Ball-Head Impacts	Total Players	Ball-Head Impacts per Player	Ball-Head Impacts per Game	95% CI	Range (min-max)
U12 Girls	30	240	0.13 ± 0.07	3.00 ± 1.70 †,#	1.78-4.22	1-6
U12 Boys	101	254	0.40 ± 0.16	10.10 ± 3.90 †,#	7.31-12.89	4-17
U13 Girls	54	300	0.18 ± 0.13	5.40 ± 4.20 †	2.4-8.4	2-16
U13 Boys	133	294	0.45 ± 0.24	13.30 ± 7.45 #	4.46-9.34	4-25
U14 Girls	69	288	0.24 ± 0.11	6.90 ± 3.41 †	4.46-9.34	3-12
U14 Boys	192	298	0.64 ± 0.24	19.20 ± 7.44 †	13.88-24.52	8-34
Females	153	828	0.18 ± 0.11	5.10 ± 3.56 §	3.83-6.37	1-16
Males	426	846	0.50 ± 0.24	14.20 ± 7.34 §	11.57-16.83	4-34
U12	131	494	0.26 ± 0.19	6.55 ± 4.67 *	4.36-8.74	1-17
U13	187	594	0.31 ± 0.23	9.35 ± 7.15	6.01-12.69	2-25
U14	261	586	0.44 ± 0.28	13.05 ± 8.46 *	9.09-17.01	3-34
Total	579	1674	0.34 ± 0.24	9.65 ± 7.33	7.76-11.54	1-34

Ball-Head Impacts per Game and Ball-Head Impacts per Player: mean ± standard deviation; CI=confidence interval;

§ Males > Females;

* U14 > U12;

† U14 boys > U12 girls, U12 boys, U13 girls, U14 girls;

# U12 boys, U13 boys > U12 girls.