Table 4

 Relations between manual materials handling and low back pain lasting seven or more consecutive days after one year of follow up (LBP at t1) in univariate analyses

Variable at baselinenLBP at t1RR95% CIp Value*
n%
RR, relative risk; 95% CI, 95% confidence interval.
*Calculated with χ2 tests.
Pushing or pulling heavy loadsNo322319.61.000.077
<1 time/hour2012713.41.40(0.86–2.27)
⩾1 time/hour1833016.4 1.70 (1.07–2.72)
Lifting or carrying loadsNo122129.81.000.430
⩽10 kg831113.31.35(0.62–2.91)
>10 kg, ⩽25 kg, ⩽12 times/hour1221512.31.25(0.61–2.56)
>10 kg, ⩽25 kg, >12 times/hour50714.01.42(0.60–3.40)
>25 kg, ⩽12 times/hour3103912.61.28(0.69–2.36)
>25 kg, >12 times/hour13430.8 3.13 (1.18–8.33)