Table 5.
Associations of the three earlier found risk factors (percentage of the working time in a flexed position, number of lifts in a 8 h working day, number of lifts ≥25 kg in a 8 h working day) with LBP based on logistic regression, adjusted for confounders (left columns) and adjusted for confounders and CLBL (right columns). Besides, association of CLBL with LBP adjusted for all earlier found risk factors separately are shown
| Risk factor | LBP | No LBP | OR (95 % CI), n = 1,086† | OR (95 % CI), n = 1,086† |
|---|---|---|---|---|
| Time in trunk flexion | ||||
| ≤5 % time ≥30° | 256 | 287 | Referencea | Referenceb |
| 5–10 % time ≥30° | 96 | 110 | 1.01 (0.73–1.47) | 1.15 (0.74–1.78) |
| >10 % time ≥30° & ≤5 % time ≥60° | 120 | 120 | 1.15 (0.83–1.58) | 0.91 (0.57–1.46) |
| >5 % time ≥60° | 65 | 32 | 2.35 (1.46–3.79)* | 1.45 (0.77–2.73) |
| Number of lifts | ||||
| Never | 151 | 161 | Referencea | Referenceb |
| Never ≥10 kg/working day | 81 | 94 | 0.74 (0.50–1.09) | 0.69 (0.45–1.06) |
| Never ≥25 kg/working day | 146 | 156 | 0.96 (0.68–1.36) | 0.77 (0.51–1.17) |
| 1–15 times ≥25 kg/working day | 96 | 107 | 0.86 (0.59–1.27) | 0.73 (0.44–1.19) |
| >15 times ≥25 kg/working day | 63 | 31 | 2.22 (1.33–3.72)* | 1.60 (0.88–2.92) |
| Number of lifts ≥25 kg | ||||
| Never | 378 | 411 | Referencea | Referenceb |
| 1–15 time/working day | 96 | 107 | 0.93 (0.67–1.29) | 0.92 (0.63–1.34) |
| >15 times/working day | 63 | 31 | 2.38 (1.48–3.82)* | 2.03 (1.23–3.36)* |
| CLBL | ||||
| 1st quintile | Reference1 | |||
| 2nd quintile | 1.06 (0.70–1.59) | |||
| 3th quintile | 0.83 (0.51–1.33) | |||
| 4th quintile | 1.03 (0.60–1.78) | |||
| 5th quintile | 1.89 (1.04–3.45)* | |||
| CLBL | ||||
| 1st quintile | Reference2 | |||
| 2nd quintile | 0.97 (0.62–1.51) | |||
| 3th quintile | 0.88 (0.55–1.41) | |||
| 4th quintile | 1.05 (0.62–1.76) | |||
| 5th quintile | 1.96 (1.15–3.36)* | |||
| CLBL | ||||
| 1st quintile | Reference3 | |||
| 2nd quintile | 1.06 (0.71–1.60) | |||
| 3th quintile | 0.85 (0.56–1.31) | |||
| 4th quintile | 0.99 (0.62–1.57) | |||
| 5th quintile | 1.85 (1.17–2.92)* | |||
B regression coefficient, OR odds ratio, CI confidence interval
* Significant risk factor for LBP
†Of 1,086 workers data on the occurrence of LBP during follow-up, physical exposure at work and all confounders were available
aAdjusted for the confounders: age, gender, exercise behaviour during leisure time, quantitative job demands, decision authority, skill discretion, supervisor support, co-worker support, driving a vehicle during work and leisure time, flexion/rotation of the trunk during leisure time and moving heavy loads during leisure time
bAdjusted for both above mentioned confounders and CLBL
1Adjusted for both above mentioned confounders and ‘Percentage of the working time in a flexed position’
2Adjusted for both above mentioned confounders and ‘Number of lifts in an 8 h working day’
3Adjusted for both above mentioned confounders and ‘Number of lifts ≥25 kg in an 8 h working day’
CLBL Cumulative low back load
LBP Low back pain