Table 2.

Head impact statistics (Mann–Whitney U test) in the noncollar and collar groups in the two football seasons

Season 1
	Noncollar (n = 10)		Collar (n = 12)
	Range	Median	Range	Median	U value	Critical U value	P
Total hits >10g	523–3323	1870	213–4954	1716	56	29	0.818
>20g	234–1049	602	327–1574	718	48	29	0.447
>50g	36–218	80	40–289	145	37.5	29	0.147
>100g	2–28	9	2–71	15	38.5	29	0.168
Total g‐force >10g	13591–68843	39822	18570–87101	39851	51	29	0.575
>20g	9330–39254	21312	11728–58860	28411	42	29	0.250
>50g	2504–16554	5899	2708–23769	10730	40	29	0.197
>100g	284–3515	1005	242–8342	1827	40	29	0.197
Average g‐force >10g	18.63–27.35	22.01	16.26–33.42	24.47	35	29	0.105
>20g	31.19–40.55	36.64	32.45–45.70	37.37	53	29	0.667
>50g	68.36–77.74	73.66	66.01–82.25	71.83	45	29	0.337
>100g	116.66–142.08	124.18	112.19–135.92	124.41	57	29	0.873

Season 2
	Noncollar (n = 7)		Collar (n = 9)
	Range	Median	Range	Median	U value	Critical U value	P
Total hits >10g	1436–3522	2581	962–14749	4494	18	10	0.271
>20g	586–1161	818	428–3359	1261	17	10	0.222
>50g	92–292	157	51–713	171	24	10	0.682
>100g	19–53	26	6–97	24	24.5	10	0.726
Total g‐force >10g	36089–77986	58121	26637–203635	101277	19	10	0.327
>20g	23473–49724	31940	17836–132870	43787	21	10	0.453
>50g	7025–23269	11939	3775.5–53248	12908	24	10	0.682
>100g	2371–7279	3833.8	830.4–12183	3508	27	10	0.952
Average g‐force >10g	18.88–28.16	22.52	13.81–27.69	22.54	24	10	0.682
>20g	22.27–42.83	40.06	33.08–43.99	37.08	16	10	0.184
>50g	75.26–80.13	79.25	72.74–80.95	74.68	17	10	0.222
>100g	124.80–147.45	137.34	123.09–146.16	126.66	16	10	0.184