NOIRS 1997 Abstracts of the National Occupational Injury Research Symposium 1997. Washington, DC: National Institute for Occupational Safety and Health, 1997 Oct; :60
Back injuries are the single most costly workplace injury and have received much attention in workplaces which require frequent heavy (>25 pounds) lifting. However, in the retail merchandise industry, weights of merchandise are generally modest and seldom above 25 pounds, suggesting that material handling-related back injuries might be of lesser importance relative to trauma-related causes of back injuries. In a typical retail merchandise store, causes of trauma-related back injury include falls associated with the use of ladders, wet surfaces, and being struck by falling merchandise. All of these factors suggest the potential importance of trauma-related back injuries. This analysis documents the distribution and determinants of material handling-related and trauma-related back injuries in this large and growing segment of the workforce. As part of a larger prospective intervention study, the authors collected workers' compensation and payroll data from 51,363 store workers in 97 stores (of the same chain) over a 10-month period in 1996 and 1997. Strain or sprain of the back associated with material handling was the most frequent back injury: 269 of 350 back injuries (78%). Trauma-related back injuries, which included caught by/between, struck by, miscellaneous, slip, trip, or fall accounted for 81 (23%) of the total back injuries. Days off work, a measure of severity, suggested material handling-related injuries were more severe (31% with 1 or more days off), compared with 17% with 1 or more days off for trauma-related back injuries. The risk factor profiles were similar. In both material handling-related and trauma-related back injuries, less experience on the job was strongly associated with a claim, after adjusting for age, job title, and sex using a Poisson regression model. For material handling-related back injuries, the rate ratio was 2.75, p<.0001 for workers with 2.2 months or less of experience compared to those with 10.7 or more months of experience. For trauma-related back injuries for the same groups, the rate ratio was 3.00, p<.01. Sex and age were not significant risk factors for either material handling or trauma-related back injuries. The excess risk of material-handling- related back injuries for stockers and receivers compared to workers who only occasionally perform material handling tasks (rate ratio = 1.75, p<.0001) was similar for trauma-related back injuries (rate ratio = 1.58, p = .09). The only really important difference in the risk factor profile was that the material handling-related back injuries for workers with intermediate levels of job experience (between 2.2 and 10.7 months) had rate ratios above 2.0, but for trauma-related back injuries the rate ratios for the same categories of experience were below 2.0. In summary, we found that the majority of back injuries in these workers were related to material handling and that the severity level for material handling back injuries was higher. But the similarity of risk factor profiles suggests that prevention efforts, whether directed at material handling or at trauma hazards, could be directed at the same workers (stockers and receivers with the least job experience) for the biggest return per dollar of prevention effort.