Table 7 .
Maximum voltage, mean voltage, and integrated area of the rectified EMG of the manipulated trials presented as a proportion of the control trials when subjects executed maximum effort countermovement jumps
| Added Gravity | Added head mass | ||||||
|---|---|---|---|---|---|---|---|
| N | Maximum voltage | Mean voltage | Integrated area | Maximum voltage | Mean voltage | Integrated area | |
| Sternohyoid | 16 | 1.00 ± 0.21 (p = 1) |
1.23 ± 0.29 (p = 0.324) |
0.92 ± 0.20 (p = 1) |
1.00 ± 0.21 (p = 0.695) |
1.00 ± 0.21 (p = 1) |
1.00 ± 0.21 (p = 1) |
| Sternocleidomastoid | 16 | 0.97 ± 0.15 (p = 1) |
1.18 ± 0.31 (p = 0.308) |
1.06 ± 0.27 (p = 0.978) |
0.94 ± 0.22 (p = 0.623) |
1.03 ± 0.29 (p = 1) |
1.06 ± 0.27 (p = 1) |
| Masseter | 11 | 1.20 ± 0.52 (p = 1) |
1.25 ± 0.47 (p = 0.748) |
1.15 ± 0.48 (p = 1) |
0.83 ± 0.38 (p = 0.623) |
0.85 ± 0.39 (p = 0.637) |
0.86 ± 0.39 (p = 0.39) |
| Levator scapulae | 12 | 1.08 ± 0.28 (p = 1) |
1.22 ± 0.46 (p = 0.28) |
1.10 ± 0.41 (p = 1) |
1.04 ± 0.32 (p = 0.864) |
1.10 ± 0.51 (p = 1) |
1.13 ± 0.53 (p = 1) |
| Upper trapezius | 16 | 1.19 ± 0.42 (p = 0.784) |
1.09 ± 0.29 (p = 0.748) |
0.99 ± 0.25 (p = 1) |
0.94 ± 0.39 (p = 0.136) |
0.92 ± 0.17 (p = 0.056) |
0.95 ± 0.14 (p = 0.136) |
| Splenius capitis | 16 | 0.94 ± 0.28 (p = 0.819) |
1.03 ± 0.23 (p = 0.748) |
0.93 ± 0.20 (p = 0.889) |
1.10 ± 0.40 (p = 0.864) |
1.06 ± 0.22 (p = 1) |
1.10 ± 0.18 (p = 0.343) |
| Semi spinalis (right) | 16 | 0.98 ± 0.24 (p = 1) |
1.03 ± 0.17 (p = 0.748) |
0.94 ± 0.18 (p = 0.536) |
0.97 ± 0.32 (p = 0.695) |
0.94 ± 0.17 (p = 0.637) |
0.98 ± 0.17 (p = 1) |
| Semi spinalis (left) | 10 | 1.03 ± 0.31 (p = 1) |
1.11 ± 0.23 (p = 0.345) |
1.01 ± 0.20 (p = 1) |
0.92 ± 0.28 (p = 0.695) |
0.99 ± 0.20 (p = 1) |
1.00 ± 0.18 (p = 1) |
Values are mean ± standard deviation, expressed as a ratio of activity during the control jumps.
P-values as shown in parentheses and were calculated using the Holm–Bonferroni Sequential Correction relative to control trials.