Table 4. Pre and post IMVC values of the neck force (N) and the head acceleration (G) for IG1 (n = 11), IG2 (n = 13) and CG (n = 13). Values are reported as mean ± standard deviation.

		Neck flexion [N]	Neck extension [N]	Standing header [G]	Jumping header [G]	Running header [G]	Post-jumping header [G]	Post-running header [G]
Pre ± SD	IG1	267.8 ± 82.4	497.4 ± 107.9	6.3 ± 0.9	6.2 ± 1.2	8.4 ± 1.3	5.4 ± 1.3	7.5 ± 1.2
	IG2	261.9 ± 32.4	439.5 ± 104.9	6.2 ± 1.3	5.5 ± 0.5	7.3 ± 1.4	5.7 ± 1.5	7.4 ± 1.9
	CG	232.5 ± 55.9	526.7 ± 117.7	6.6 ± 1.3	6.0 ± 1.2	7.5 ± 1.3	6.0 ± 1.8	7.3 ± 1.4
CI 95 %	IG1	229.6-306.1	231.5-275.6	5.5-7.0	5.6-6.8	7.6-9.3	4.4-6.3	6.5-8.4
	IG2	217.8-302.1	218.7-303.1	5.4-7.0	4.8-6.2	6.4-8.2	4.7-6.8	6.3-8.4
	CG	198.2-267.8	197.1-267.8	6.0-7.3	5.3-6.5	6.8-8.3	5.1-6.9	6.4-8.1
Post ± SD	IG1	304.1 ± 89.8	495.4 ± 115.7	6.7 ± 2.0	5.5 ± 1.2	7.4 ± 1.3	5.1 ± 1.5	7.2 ± 1.5
	IG2	326.7 ± 63.8	443.4 ± 100.0	6.3 ± 1.0	5.3 ± 0.6	7.1 ± 1.0	5.1 ± 0.7	6.7 ± 1.6
	CG	260.9 ± 72.6	487.5 ± 117.7	6.2 ±1.3	6.0 ± 1.1	7.4 ± 1.2	5.4 ± 1.7	7.3 ± 0.9
CI 95 %	IG1	257.0-351.2	270.7-324.7	5.7-7.6	4.9-6.1	6.7-8.1	4.3-6.0	6.3-8.0
	IG2	274.7-379.6	274.6-379.6	5.3-7.3	4.6-6.0	6.3-7.9	4.1-6.1	5.8-7.6
	CG	216.8-304.1	216.8-304.1	5.3-7.0	5.4-6.6	6.7-8.1	4.6-6.2	6.6-8.1
∆ PRE-POST	IG1	+36.3 ± 21.6	-1.9 ± 55.9	0.4 ± 2.0	-0.7 ± 1.4	-1.0 ± 1.9	-0.2 ± 2.1	-0.3 ± 1.6
	IG2	+65.7 ± 54.9	+4.9 ± 50.0	0.1 ± 1.4	-0.2 ± 0.9	-0.2 ± 1.4	-0.6 ± 1.4	-0.7 ± 1.2
	CG	+27.5 ± 27.5	-39.2 ± 55.9	-0.4 ± 1.2	0.1 ± 1.2	-0.1 ± 1.6	-0.6 ± 1.3	0.0 ± 1.4
∆ CI 95 %	IG1	21.6-51.0	-39.2-36.2	-0.9-1.7	-1.7-0.3	-2.3-0.2	-1.6-1.2	-1.4-0.8
	IG2	23.5-107.9	-33.3-43.1	-1.0-1.2	-0.9-0.5	-1.3-0.8	-1.7-0.5	-1.6-0.3
	CG	10.8-54.9	-73.5 - (-5.8)	-1.1-0.3	-0.6-0.6	-1.1-0.8	-1.3-0.2	-0.8-0.9

CI 95% confidence interval, ∆ PRE-POST Difference between PRE- and POST-Phase, ∆ CI 95% confidence interval of ∆ PRE-POST