Table 2:
Effect of stability condition on shoulder muscle activation.
| Muscle | Floor %MVC (SD) | Green %MVC (SD) | Blue %MVC (SD) | Condition Main Effect (p-value) |
|---|---|---|---|---|
| Anterior Deltoid | 11.0 (7.2) | 9.9 (7.0) | 9.7 (7.0) | 0.023* |
| Posterior Deltoid | 12.5 (8.5) | 12.1 (9.1) | 12.0 (8.3) | 0.506 |
| Infraspinatus | 26.3 (10.0) | 26.0 (9.9) | 25.4 (10.5) | 0.656 |
| Lower Trapezius | 16.2 (8.9) | 15.4 (9.4) | 14.5 (8.2) | 0.029* |
| Upper Trapezius | 4.6 (4.6) | 4.3 (4.1) | 4.3 (4.1) | 0.103 |
| Serratus Anterior | 15.0 (9.3) | 13.5 (9.2) | 13.0 (9.6) | <0.001* |
| Pectoralis | 8.7 (7.2) | 9.6 (8.6) | 9.6 (8.1) | 0.135 |
| Triceps | 23.1 (11.6) | 25.1 (12.8) | 25.1 (12.5) | 0.002# |
(*)
EMG activity decreased as task stability decreased.
(#)
EMG activity increased as task stability decreased.