Table 2.
Pearson correlations and common variance (in parentheses) between force output and selected electromyographic, cerebral, and muscle hemodynamic variables during intermittent contractions of the biceps brachii at three intensities (N = 11, critical ‘r’ value = 0.58).
| Variable | Pearson r (% r2) between force output and variables at three intensities | ||
|---|---|---|---|
| 20% MVC | 40% MVC | 60% MVC | |
| RMS | 0.73* (53.6%) | 0.71* (50.2%) | 0.59* (34.8%) |
| Delta cerebral HbO2 | 0.46 (21.4%) | 0.19 (3.1%) | 0.24 (5.6%) |
| Delta cerebral HHb | 0.35 (12.2%) | 0.33 (10.9%) | 0.04 (1.8%) |
| Delta muscle HbO2 | 0.64* (41.0%) | 0.62* (38.4%) | 0.63* (39.8%) |
| Delta muscle HHb | 0.54 (29.5%) | 0.57 (32.5%) | 0.51 (26.0%) |
*
Correlation significant at P < 0.05. Note: force output was significantly correlated with RMS at 20 and 40% MVC but not at 60% MVC. Force output was significantly correlated with muscle HbO2 but not cerebral HbO2, cerebral HHb and muscle HHb.