Effect of manual handling weight for lifting and carrying on the severity of acute occupational low back pain.

PURPOSE: Preventing the progression of occupational low back pain (LBP) is a critical occupational safety and health concern, alongside reducing its incidence. Manual handling of heavy loads may increase LBP severity. This study investigates the impact of lifting and carrying weights on LBP severity in affected workers.

METHODS

A total of 2418 cases of acute occupational LBP, each resulting in more than four days of absence from work, were analyzed. These cases, reported as industrial accidents in Japan 2018-2019, were categorized into four weight-handling groups: < 10, 10-20, 20-30, and ≥ 30 kg. LBP severity was defined based on the duration of work absence, as determined by a physician's diagnosis at the onset, and was categorized into four groups: 4-7, 8-14, 15-30, and ≥ 31 days. Multinomial logistic regression analysis was conducted to assess the relationship between handling weights and absence duration.

RESULTS

The odds ratio (OR) for absence of ≥ 31 days compared with 4-7 days increased with heavier handling weights. Notably, workers handling 30 kg or more weights had a significantly higher OR than those under 10 kg (OR: 1.75; 95% CI: 1.11-2.77). The ORs for absence of 8-14 and 15-30 days compared with 4-7 days showed no significant association with handling weight.

CONCLUSION

Lifting and carrying heavier loads were associated with increased LBP severity and prolonged work absences. Minimizing manual handling loads may be a practical strategy to reduce the severity of acute occupational LBP and prevent prolonged work absences.