Table 1. Comparison of muscle fatigue and pain according to cervical flexion angle.
| Muscle | 0° | 30° | 50° | |
|---|---|---|---|---|
| Fatigue (Hz) | RtUT** | 42.5 ± 13.9 | 32.0 ± 15.7 | 26.3 ± 11.4 |
| LtUT** | 38.2 ± 16.5 | 26.7 ± 13.1 | 18.7 ± 10.1 | |
| RtCES | 31.4 ± 15.6 | 31.2 ± 15.9 | 24.4 ± 11.6 | |
| LtCES | 31.9 ± 14.9 | 29.7 ± 10.5 | 28.3 ± 13.2 | |
| Pain (Lb) | RtUT* | 15.9 ± 2.9 | 15.6 ± 1.8 | 14.7 ± 2.8 |
| LtUT** | 16.6 ± 2.9 | 16.5 ± 2.4 | 15.1 ± 3.2 | |
| RtCES | 12.5 ± 2.9 | 12.0 ± 3.1 | 11.7 ± 2.6 | |
| LtCES | 13.1 ± 2.5 | 12.8 ± 3.3 | 11.9 ± 2.6 | |
RtUT: right upper trapezius; LtUT: left upper trapezius; RtCES: right cervical erector spinae; LtCES: left cervical erector spinae, *p<0.05, **p<0.01