Physical risk factors for onset of neck/shoulder pain (symptom cases), and neck/shoulder pain with pressure tenderness (clinical cases) among industrial and service workers
| Symptom cases | Clinical cases | |||||||
|---|---|---|---|---|---|---|---|---|
| Physical risk factor | n | Cases | OR*crude | ORadj† (95% CI) | n | Cases | ORcrude | ORadj† (95% CI) |
| *OR, odds ratio. | ||||||||
| †Adjustment for individual factors: age, gender, body mass index, pain pressure threshold, intrinsic effort, physical leisure time activity, psychosocial factors, and level of distress. | ||||||||
| ‡Reference category includes workers with non-repetitive work tasks. | ||||||||
| §Maximal voluntary contraction. | ||||||||
| Repetitivity (shoulder movements/min) | ||||||||
| Reference‡ | 1536 | 179 | 1.0 | 1.0 | 1600 | 14 | 1.0 | 1.0 |
| Low (1–15 movements/min) | 1803 | 239 | 1.2 | 1.1 (0.9 to 1.3) | 1896 | 27 | 1.6 | 1.3 (0.7 to 2.6) |
| High (16–40 movements/min) | 1132 | 204 | 1.7 | 1.5 (1.2 to 1.9) | 1204 | 40 | 3.9 | 3.0 (1.5 to 5.8) |
| Force requirements | ||||||||
| Reference | 1536 | 179 | 1.0 | 1.0 | 1600 | 14 | 1.0 | 1.0 |
| Low (<10% of MVC)§ | 1953 | 293 | 1.3 | 1.2 (0.9 to 1.5) | 2061 | 48 | 2.7 | 1.9 (1.0 to 3.6) |
| High (⩾10% of MVC) | 986 | 152 | 1.4 | 1.3 (1.0 to 1.7) | 1045 | 19 | 2.1 | 2.0 (1.0 to 4.2) |
| Neck flexion (proportion of task cycle time with neck flexed >20°) | ||||||||
| Reference | 1534 | 179 | 1.0 | 1.0 | 1598 | 14 | 1.0 | 1.0 |
| Low (<66% of time) | 1733 | 235 | 1.2 | 1.1 (0.9 to 1.4) | 1837 | 28 | 1.8 | 1.4 (0.7 to 2.9) |
| High (⩾66% of time) | 1206 | 210 | 1.6 | 1.4 (1.1 to 1.8) | 1269 | 39 | 3.6 | 2.6 (1.3 to 5.1) |
| Lack of recovery time (proportion of task cycle time without micropauses) | ||||||||
| Reference | 1536 | 179 | 1.0 | 1.0 | 1600 | 14 | 1.0 | 1.0 |
| Low (<80% of time) | 476 | 68 | 1.3 | 1.2 (0.9 to 1.6) | 496 | 5 | 1.2 | 1.0 (0.4 to 2.9) |
| High (⩾80% of time) | 2371 | 367 | 1.4 | 1.3 (1.0 to 1.5) | 2518 | 60 | 2.8 | 2.1 (1.1 to 3.9) |