Table 2.
Mean and SD of normalized EMG activity (area under the curve and peak EMG activity) for anterior and middle deltoids.
| L1 | L2 | L3 | L4 | M1 | M2 | H1 | H2 | |||
|---|---|---|---|---|---|---|---|---|---|---|
| Anterior deltoid | RMS (% of MVC) | Mean | 32.41 | 49.60 | 67.86 | 90.70 | 45.97 | 65.88 | 64.90 | 119.38 |
| SD | 10.85 | 35.67 | 37.00 | 58.02 | 40.89 | 40.31 | 24.32 | 44.66 | ||
| Peak EMG activity (% of MVC) | Mean | 37.93 | 65.45 | 75.71 | 87.35 | 39.91 | 54.02 | 56.66 | 87.28 | |
| SD | 13.05 | 44.40 | 42.11 | 50.49 | 30.79 | 35.68 | 17.90 | 34.74 | ||
| Middle deltoid | RMS (% of MVC) | Mean | 35.13 | 43.16 | 34.04 | 46.63 | 32.92 | 55.52 | 50.83 | 100.87 |
| SD | 28.39 | 32.20 | 40.91 | 44.91 | 32.51 | 46.14 | 32.17 | 62.23 | ||
| Peak EMG activity (% of MVC) | Mean | 38.84 | 50.08 | 47.55 | 53.86 | 27.63 | 43.64 | 41.39 | 68.50 | |
| SD | 29.15 | 42.58 | 38.14 | 36.28 | 23.21 | 33.61 | 26.19 | 40.30 | ||
Legend: SD: standard deviation; MVC: Maximum voluntary contraction; L1: lower shelf, weight 2.3kg; L2: lower shelf, weight 6.8 kg; L3: lower shelf, weight 13.6 kg; L4: lower shelf, weight 22.7kg; M1: medium shelf, weight 2.3 kg; M2: medium shelf, weight 6.8 kg; H1: higher shelf, weight 2.3 kg; H2: higher shelf, weight 6.8 kg.