Table 2.
Comparison of full-shift EMG summary measures (mean [SE]) across parlour configurations.
| Summary Measure* | Herringbone (n=17)† |
Parallel (n=32) |
Rotary (n=11) |
Total (n=60) |
|---|---|---|---|---|
| Upper trapezius | ||||
| Mean RMS (%MVE) | 9.6 (0.7) | 8.6 (0.7) | 9.8 (1.9) | 9.6 (4.4) |
| Gap frequency (#/min) | 1.2 (0.4) | 1.5 (0.2) | 1.9 (0.8) | 2.6 (3.0) |
| Muscular rest (% time) | 1.1 (0.4) | 1.7 (0.2) | 2.8 (1.0) | 6.0 (15.5) |
| Traditional APDF (%MVE) | ||||
| Static | 1.3 (0.2) | 1.2 (0.1) | 1.0 (0.2) | 1.4 (1.0) |
| Median | 7.2 (0.6) | 5.8 (0.5) | 7.1 (1.5) | 6.9 (3.6) |
| Peak | 20.8 (1.5) | 19.9 (1.8) | 21.7 (3.7) | 21.2 (9.5) |
| Active APDF (%MVE) | ||||
| Static | 6.0 (0.1) | 5.9 (0.1) | 5.9 (0.3) | 6.1 (0.6) |
| Median | 11.2 (0.5) | 10.9 (0.5) | 11.2 (1.2) | 11.4 (3.1) |
| Peak | 25.1 (1.4) | 26.0 (1.8) | 25.8 (3.5) | 26.5 (9.1) |
| Anterior deltoid | ||||
| Mean RMS (%MVE)A | 5.9 (0.4) | 7.5 (0.5) | 6.5 (1.9) | 7.6 (3.5) |
| Gap frequency (#/min)A,B | 15.8 (1.0) | 11.6 (1.1) | 12.0 (1.1) | 12.8 (5.1) |
| Muscular rest (% time | 21.4 (1.9) | 19.1 (2.3) | 29.4 (3.9) | 21.7 (11.3) |
| Traditional APDF (%MVE) | ||||
| Static | 0.3 (0.0) | 0.3 (0.0) | 0.2 (0.0) | 0.3 (0.2) |
| MedianA,C | 1.6 (0.2) | 2.4 (0.3) | 1.1 (0.2) | 2.2 (1.5) |
| PeakA | 18.1 (1.2) | 22.6 (1.4) | 18.6 (4.5) | 23.2 (10.6) |
| Active APDF (%MVE) | ||||
| Static | 6.2 (0.1) | 6.3 (0.1) | 6.2 (0.2) | 6.4 (0.6) |
| Median | 12.9 (0.5) | 14.2 (0.4) | 13.1 (1.4) | 14.6 (3.9) |
| PeakA | 28.7 (1.5) | 35.4 (1.4) | 27.9 (4.5) | 36.6 (18.1) |
| Biceps | ||||
| Mean RMS (%MVE)A | 5.2 (0.3) | 7.1 (0.6) | 5.4 (0.5) | 7.7 (5.5) |
| Gap frequency (#/min)A,B | 9.6 (0.5) | 7.1 (0.6) | 6.4 (0.4) | 7.7 (2.8) |
| Muscular rest (% time)A,C | 17.7 (1.1) | 12.4 (1.3) | 19.0 (1.5) | 15.2 (6.5) |
| Traditional APDF (%MVE) | ||||
| StaticC | 0.2 (0.0) | 0.3 (0.0) | 0.2 (0.0) | 0.3 (0.3) |
| Median | 3.1 (0.2) | 4.0 (0.5) | 3.0 (0.4) | 4.3 (3.1) |
| PeakA | 13.1 (0.8) | 18.3 (1.5) | 14.3 (1.3) | 19.6 (14.1) |
| Active APDF (%MVE) | ||||
| StaticA | 5.7 (0.0) | 5.9 (0.1) | 5.7 (0.1) | 5.9 (0.6) |
| MedianA | 9.3 (0.2) | 11.2 (0.5) | 10.0 (0.4) | 11.5 (4.4) |
| PeakA | 19.5 (0.8) | 25.1 (1.6) | 21.6 (1.5) | 26.9 (16.1) |
| Forearm flexors | ||||
| Mean RMS (%MVE)B | 11.0 (0.9) | 10.0 (0.9) | 8.3 (0.5) | 11.1 (5.6) |
| Gap frequency (#/min) | 5.4 (0.5) | 6.5 (0.5) | 5.1 (0.6) | 5.8 (2.4) |
| Muscular rest (% time) | 9.0 (1.5) | 10.6 (1.1) | 10.9 (1.4) | 10.3 (5.7) |
| Traditional APDF (%MVE) | ||||
| Static | 0.5 (0.1) | 0.4 (0.0) | 0.4 (0.1) | 0.5 (0.4) |
| Median | 5.3 (0.6) | 4.5 (0.4) | 4.4 (0.2) | 5.5 (3.0) |
| PeakB | 27.7 (2.1) | 26.1 (2.2) | 21.1 (1.5) | 28.6 (15.0) |
| Active APDF (%MVE) | ||||
| Static | 6.1 (0.1) | 6.1 (0.1) | 5.9 (0.1) | 6.2 (0.5) |
| Median | 13.2 (0.6) | 13.3 (0.6) | 11.9 (0.5) | 13.7 (3.6) |
| PeakB,C | 40.1 (2.8) | 37.9 (2.3) | 29.8 (2.0) | 39.9 (17.1) |
| Forearm extensors | ||||
| Mean RMS (%MVEC | 6.3 (0.6) | 8.7 (0.9) | 5.7 (0.7) | 8.3 (4.2) |
| Gap frequency (#/min) | 6.1 (0.5) | 5.3 (0.4) | 5.6 (0.4) | 5.6 (2.1) |
| Muscular rest (% time)C | 11.8 (1.4) | 8.8 (0.8) | 14.9 (1.6) | 10.9 (5.3) |
| Traditional APDF (%MVE) | ||||
| StaticC | 0.4 (0.1) | 0.5 (0.1) | 0.3 (0.0) | 0.5 (0.3) |
| Median | 4.2 (0.4) | 4.7 (0.4) | 3.7 (0.4) | 5.1 (2.8) |
| PeakA,C | 14.7 (1.3) | 22.0 (2.0) | 13.2 (1.6) | 20.0 (10.4) |
| Active APDF (%MVE) | ||||
| Static | 5.7 (0.1) | 5.8 (0.1) | 5.7 (0.1) | 5.9 (0.5) |
| MedianA,C | 9.6 (0.4) | 11.5 (0.6) | 9.4 (0.6) | 11.3 (3.4) |
| Peak | 21.0 (1.3) | 29.6 (2.1) | 19.1 (1.7) | 28.0 (13.3) |
*
Post hoc comparisons (p<0.05) of summary metrics between parlor configuration: A = herringbone vs parallel; B = herringbone vs rotary; C = parallel vs rotary
†
16 observations for the forearm extensor muscle group