Back injury in heavy industry: Examining peak and cumulative back muscle activity for risk exposure assessment

Despite increasing technological advances, heavy industries remain physically demanding, with high back injury rates among workers. In BC, more than 17,000 compensation claims for back strain accounted for 25 per cent of all claims for 2001. More than a quarter of these claims come from employees in the forestry, wood and paper products, construction, transportation, and warehousing industries. Activities such as lifting, carrying or pushing objects subject workers to forceful exertions, repetitive movements and awkward postures, all of which can contribute to back injuries. Injuries are thought to be caused by both “peak” or maximal loads (such as lifting a heavy box once) and the total load over time (repeatedly lifting boxes throughout the day). However, most studies have focused solely on peak loads. Catherine Trask is conducting the first study to measure muscle loading over time among workers in these five heavy industries. Catherine is comparing how peak and cumulative muscle loads impact back strain, and whether total load is an important risk factor for back injury. The results may identify the maximum safe physical loads for workers in heavy industry, which would help reduce injuries, make industrial workplaces safer, and reduce claim costs.