Table 2.
Effect of pulse duration on extra force and sustained EMG activity by muscle group.
| 0.2 ms | 1 ms | 2 ms | P value | |
|---|---|---|---|---|
| Extra force PF (%) | 48.0 ± 59.8bc | 75.7 ± 83.2a | 73.2 ± 80.4a | 0.001 |
| Extra force KE (%) | 44.7 ± 100.9 | 56.5 ± 112.8 | 52.6 ± 114.1 | 0.620 |
| Extra force EF (%) | 26.0 ± 68.4 | 23.2 ± 57.7 | 28.6 ± 93.6 | 0.662 |
| Sustained soleus EMG activity (% EMGmax) | 6.2 ± 5.1bc | 8.2 ± 7.9a | 8.7 ± 8.1a | 0.001 |
| Sustained vastus lateralis EMG activity (% EMGmax) | 5.0 ± 6.8 | 4.6 ± 6.4 | 5.7 ± 7.6 | 0.300 |
| Sustained biceps brachii EMG activity (% EMGmax) | 2.7 ± 2.1b | 3.8 ± 3.3ac | 2.7 ± 2.4b | 0.002 |
PF: plantar flexors; KE: knee extensors; EF: elbow flexors. a = different from 0.2 ms, b = different from 1 ms, c = different from 2 ms. EMGmax = maximal electromyographic activity.