TABLE 2.
Normalized Mean Muscle Activation (% EMGmax ± SEM) during ER Exercisesa
| Muscle | ER at 0°ABD | ER at 90°ABD | ER With Underarm Towel | Prone ER at 90°ABD | Side-Lying ER With Underarm Towel | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean % | SEM | Mean % | SEM | Mean % | SEM | Mean % | SEM | Mean % | SEM | |
| AD | 30.4 | 5 | 126.2 | 20.5 | 20.7 | 3.7 | 16.9 | 2.8 | 21.4 | 3.2 |
| MD | 10.7 | 2.2 | 68.2 | 10.5 | 9.7 | 1.5 | 22.8 | 3.2 | 28.8 | 4.2 |
| PD | 6.4 | 1.4 | 26.8 | 4.3 | 7.1 | 1.0 | 29 | 3.9 | 29.4 | 3.9 |
| UT | 32 | 6.7 | 72 | 9.8 | 42.8 | 7.6 | 29.6 | 4.7 | 20.4 | 3.4 |
| MT | 26.8 | 3.4 | 44 | 4.8 | 27.9 | 2.4 | 59.5 | 13.6 | 67.9 | 11.2 |
| LT | 23 | 3.1 | 51.9 | 4.6 | 25.6 | 2.7 | 85.1 | 10.5 | 61.6 | 6.2 |
| SA | 37.1 | 5.1 | 160.1 | 21.1 | 40.4 | 5.7 | 127 | 28 | 40.4 | 4.2 |
| TM | 18.2 | 1.8 | 36.7 | 3.2 | 26.5 | 2.7 | 68.4 | 7 | 50.5 | 4.8 |
| ULD | 20.1 | 2.9 | 53 | 7.2 | 22.3 | 3.8 | 63.8 | 8.6 | 51.5 | 7.2 |
| LLD | 15.8 | 2.6 | 34.8 | 5.2 | 16 | 3 | 51.8 | 8.7 | 45.9 | 7.8 |
| UPM | 70.2 | 9.2 | 31.2 | 3.5 | 108.8 | 15.1 | 32 | 2.2 | 41.2 | 3.7 |
| LPM | 62 | 10.2 | 39.9 | 3.8 | 96.8 | 15.6 | 37 | 2.7 | 47.7 | 9.1 |
| SSP | 32.6 | 3.7 | 59.9 | 6.9 | 30.7 | 3.9 | 30.5 | 6.6 | 40.5 | 8.2 |
| ISP | 28.2 | 3.2 | 30.7 | 3.2 | 32.9 | 4.8 | 38 | 6.2 | 29.9 | 6.4 |
| SUBS | 32.4 | 3.3 | 75.2 | 12.4 | 45 | 7 | 104.2 | 19.4 | 85.6 | 14.3 |
| RHOM | 32.7 | 4.8 | 59.2 | 6.3 | 35.4 | 4.8 | 61.9 | 15.3 | 81.5 | 19.3 |
aABD, abduction; AD, anterior deltoid; EMGmax, electromyography amplitude at maximum external rotation force in a standard position; ER, external rotation; ISP, infraspinatus; LLD, lower latissimus dorsi; LPM, lower pectoralis major; LT, lower trapezius; MD, middle deltoid; MT, middle trapezius; PD, posterior deltoid; RHOM, rhomboid major; SA, serratus anterior; SEM, standard error of the mean; SUBS, subscapularis; SSP, supraspinatus; TM, teres major; ULD, upper latissimus dorsi; UPM, upper pectoralis major; UT, upper trapezius.