Table 3. Degrees of freedom (DoF), F and p values of mixed model analysis for Swiss versus Japanese nation, day versus night shift and shift*nation interaction are shown for rest time of trapezius muscle, 10th and 50th percentile of trapezius muscle activity, heart rate and time pressure (value at the end of the shift − value at the beginning of the shift). nJapan=22, nSwitzerland=17 for EMG parameters, nJapan=16, nSwitzerland=17 for heart rate and nJapan=20, nSwitzerland=17 for the diary.
| Parameter | Effect | DoF numerator | DoF denominator | F | p |
|---|---|---|---|---|---|
| Rest time | nation | 1 | 37 | 6.05 | 0.019 |
| shift | 1 | 37 | 0.62 | 0.435 | |
| shift*nation | 1 | 37 | 2.74 | 0.107 | |
| 10th percentile | nation | 1 | 37 | 2.26 | 0.141 |
| shift | 1 | 37 | 2.54 | 0.120 | |
| shift*nation | 1 | 37 | 5.60 | 0.023 | |
| 50th percentile | nation | 1 | 37 | 0.03 | 0.871 |
| shift | 1 | 37 | 0.00 | 0.991 | |
| shift*nation | 1 | 37 | 7.08 | 0.012 | |
| Heart rate | nation | 1 | 29 | 0.15 | 0.699 |
| shift | 1 | 29 | 38.42 | <0.001 | |
| shift*nation | 1 | 29 | 0.44 | 0.515 | |
| Time pressure | nation | 1 | 109 | 6.35 | 0.013 |
| shift | 1 | 109 | 0.40 | 0.528 | |
| time | 1 | 109 | 3.92 | 0.050 | |
| time*nation | 1 | 109 | 9.79 | 0.002 | |
| time*shift | 1 | 109 | 0.21 | 0.650 | |
| time*nation*shift | 1 | 109 | 0.18 | 0.676 |