Characteristics of the blue-collar workers (N=183) involved in the statistical analysis
| Variables | N | Per cent | Minimum | Maximum | Mean | SD |
|---|---|---|---|---|---|---|
| Age (years) | 183 | 21 | 65 | 44.9 | 9.8 | |
| Gender | ||||||
| Male | 110 | 60 | ||||
| Female | 73 | 40 | ||||
| Leisure time physical activity | ||||||
| Low | 87 | 48 | ||||
| High | 94 | 52 | ||||
| Smoking status | ||||||
| Non-smoker or ex-smokers | 99 | 59 | ||||
| ≤15 cigarettes (light smokers) | 38 | 23 | ||||
| >15 cigarettes (heavy smokers) | 31 | 18 | ||||
| Influence at work in 0–100% | 180 | 0 | 100 | 43.7 | 23.0 | |
| BMI (kg/m2) | ||||||
| >25 | 75 | 41 | ||||
| 25–30 | 72 | 39 | ||||
| >30 | 36 | 20 | ||||
| LBP intensity (0–9) | 178 | 0 | 9 | 3.0 | 2.6 | |
| RPE (0–9) | 180 | 0 | 9 | 5.5 | 1.9 | |
| Dietary habits (1–4) | 179 | 1 | 4 | 2.6 | 0.9 | |
| Physical fatigue (1–5) | 180 | 1 | 5 | 2.4 | 0.9 | |
| Slow walking duration (min/day)* | 179 | 0 | 990 | 171.6 | 166.2 | |
| Fast walking duration (min/day)* | 174 | 0 | 600 | 132.1 | 127.4 | |
| Sitting duration at work (1–6) | 182 | 1 | 6 | 4.1 | 1.2 | |
| Standing still duration at work (1–6) | 183 | 1 | 6 | 4.6 | 0.8 | |
| Measurements of sitting | ||||||
| Questionnaire-based sitting time (min/day)* | 183 | 0.0 | 900.0 | 271.8 | 160.5 | |
| Accelerometer-based sitting time (min/day) | 183 | 157.2 | 851.3 | 475.8 | 138.3 | |
RPE: 0=not hard work, 9=maximal hard work; influence at work: 0=no influence, 100=highest influence at work; LBP intensity: 0=no pain, 9=worst possible pain; dietary habits: 1=daily, 4=rarely; physical fatigue: 1=almost always, 5=never; sitting duration at work: 1=almost all the time, 6=never; standing still duration at work: 1=almost all the time, 6=never; we did not include self-reported biking and running time as potential predictors due to many missings in the data.
*The data handling strategy was inspired by the IPAQ cleaning guidelines.40
BMI, body mass index; IPAQ, International Physical Activity Questionnaire; LBP, low back pain; RPE, rating of perceived exertion.