Table 5 .

Ratio of the integrated muscle activity recorded during the added head mass trials over that recorded during the control trials when subjects ran at 2.7 ms⁻¹ on a treadmill

	N	Mean ± S.D.	P-value
Sternohyoid	16	1.24 ± 0.59	0.7
Sternocleidomastoid	16	1.30 ± 0.68	0.86
Masseter	12	0.71 ± 0.38	0.084
Levator scapulae	14	1.21 ± 0.27	0.18
Upper Trapezius	16	1.26 ± 0.24	<0.008
Splenius capitis	15	1.10 ± 0.26	0.86
Semi spinalis (right)	16	1.07 ± 0.15	0.7
Semi spinalis (left)	11	1.10 ± 0.27	0.7

Values are mean ± standard deviation, of the integrated area per locomotor cycle expressed as a ratio of activity during the control run.

P-values were calculated relative to control trials using the Holm-Bonferroni Sequential Correction.