Table 6 .
Ratio of the integrated muscle activity recorded during the added horizontal force manipulated trials over that recorded during the control trials when subjects ran at 2.7 ms−1 on a treadmill
| Forward pull | Forward pull plus head mass | Rearward pull | Rearward pull plus head mass | Forward versus rearward trials | |
|---|---|---|---|---|---|
| Sternohyoid | 3.63 ± 2.24 (N = 16) P < 0.001 |
3.74 ± 1.98 (N = 10) P = 1 |
2.27 ± 1.57 (N = 16) P < 0.001 |
2.32 ± 2.21 (N = 10) P = 1 |
F > R P = 0.01 |
| Sternocleidomastoid | 2.74 ± 1.28 (N = 16) P < 0.001 |
2.65 ± 1.29 (N = 10) P = 1 |
1.72 ± 0.68 (N = 16) P < 0.02 |
1.59 ± 0.84 (N = 10) P = 1 |
F > R P = 0.01 |
| Masseter | 1.53 ± 1.12 (N = 12) P = 0.42 |
0.84 ± 0.61 (N = 6) P = 1 |
1.17 ± 0.52 (N = 12) P = 0.57 |
0.77 ± 0.52 (N = 6) P = 1 |
No difference P = 0.64 |
| Levator scapulae | 1.78 ± 0.51 (N = 14) P < 0.05 |
1.96 ± 0.80 (N = 8) P = 1 |
2.15 ± 0.70 (N = 14) P < 0.004 |
2.18 ± 0.76 (N = 8) P = 1 |
No difference P = 0.24 |
| Upper Trapezius | 1.23 ± 0.37 (N = 16) P = 0.12 |
2.03 ± 2.24 (N = 10) P = 0.42 |
1.96 ± 0.60 (N = 16) P < 0.001 |
1.91 ± 0.72 (N = 10) P = 1 |
F < R P < 0.008 |
| Splenius capitis | 1.50 ± 0.38 (N = 15) P < 0.006 |
2.08 ± 1.26 (N = 9) P = 0.08 |
2.01 ± 0.65 (N = 15) P < 0.001 |
2.13 ± 0.82 (N = 9) P = 1 |
F < R P = 0.008 |
| Semi spinalis (right) | 1.33 ± 0.32 (N = 16) P < 0.05 |
1.37 ± 0.34 (N = 10) P = 1 |
1.82 ± 0.45 (N = 16) P < 0.001 |
1.84 ± 0.52 (N = 10) P = 1 |
F < R P < 0.008 |
| Semi spinalis (left) | 1.29 ± 0.25 (N = 11) P < 0.05 |
1.68 ± 0.44 (N = 5) P = 0.42 |
1.80 ± 0.41 (N = 11) P < 0.004 |
1.87 ± 0.28 (N = 5) P = 1 |
F < R P = 0.01 |
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 using the Holm–Bonferroni Sequential Correction relative to control trials for the forward pull and rearward pull trials; relative to the forward pull trials for the forward pull plus head mass trials; and relative to rearward pull for the rearward pull plus head mass trials.