Back belt debate returns for another round
Back belt debate returns for another round
Why not? Won't hurt; might help, expert says
The continuing debate about the efficacy of back belts in preventing low back injuries and pain is once again gaining momentum with publication of an editorial in a prominent medical journal. The author, an occupational injury and rehabilitation specialist, notes a "lack of effective strategies to prevent workplace-related back injuries" while pointing out the limitations of studies that have found back belts unhelpful.1
Timothy R. Dillingham, MD, MS, a physiatrist and associate professor in the Department of Physical Medicine and Rehabilitation at Johns Hopkins University in Baltimore, focuses on overuse syndromes and other occupational musculoskeletal injuries that lead to workers' compensation cases. Despite the current lack of evidence concerning back belts' effectiveness, "they're pretty innocuous, relatively inexpensive, and they may indeed help," he tells Hospital Employee Health.
Back injuries are a major cause of industrial disability, are the most expensive health care problem for people 30 to 50 years old, and are the leading cause of disability for those younger than 45.2 "Given the magnitude of occupationally related low back pain in terms of disability, lost productivity, and costs, the lack of effective strategies to prevent workplace-related back injuries represents a major deficiency in occupational health care," he says.
Dillingham's editorial accompanies a Dutch study that assessed the efficacy of lumbar supports - also known as back belts - and education in preventing low back pain among 312 airline cargo handlers. Overall, the randomized controlled trial found that neither lumbar supports nor education led to a reduction in low back pain incidence or sick leave. Based on those results, the researchers did not recommend either education or lumbar supports as means of preventing occupational low back pain.3
Nevertheless, Dillingham maintains his position.
'The verdict is not yet in'
"At this point, I wouldn't necessarily give up on the lumbar supports or education based on this article," he says. "The verdict is not yet in on whether they're effective or not for prevention of occupational low back pain. There is other evidence in the article that lumbar supports can be helpful for people who already have back pain, and other studies suggest lumbar supports are effective. Future studies are necessary to fully explore this because it is a very important issue."
One flaw of the Dutch study is that only 43% of the worker cohort supposedly using lumbar supports actually reported having used them on more than half of the monthly questionnaires completed during the six-month study period, Dillingham points out.
He finds flaws in many other studies that recommend against the use of back belts, as well. Only 42% of the subjects in a study of fleet service clerks who were issued back belts reported using them in a similar randomized trial showing no significant benefits from using back support belts.4 A randomized controlled trial involving nursing and environmental services workers also did not find that lumbar supports protected workers from injury,5 but Dillingham says low injury rates in both lumbar support and control groups indicate the need for larger sample sizes "to define significant intervention effects of lumbar supports."
Some studies show effectiveness
On the other hand, he notes that some studies have shown back belts to be effective in reducing lost work time and preventing low back injuries. One such study assessed the use of lumbar supports to reduce low back pain among male workers in a grocery distribution warehouse. Although compliance was not specifically assessed or reported, employee health records showed workers wearing back belts and receiving education experienced less lost workdays.6
Dillingham also mentions one of the most frequently cited studies among back-belt proponents. In the largest study to date, researchers took advantage of a companywide policy at Home Depot retail stores in California requiring workers to use back belts. Low back-injury incidence rates were compared before and after implementation for 19,000 workers (amounting to more than 101 million work-hours of exposure) during the six-year study period. Back belt compliance rates were 98%. The study found the injury incidence density rate decreased from 80 per million work hours before the policy was implemented to 20 per million work hours afterward. Low back injury reductions of 40% to 90% were seen in populations at highest risk.7
But Lytt Gardner, PhD, a research epidemiologist in the division of safety research of the National Institute for Occupational Safety and Health (NIOSH) in Morgantown, WV, contends that the Home Depot study is flawed, as well.
"It was not a prospective design, and there may have been other interventions going on. For example, equipment changes such as the use of pallet jacks for moving freight nonmanually were introduced during the study period. The interpretation of results is debatable. We're not convinced," he says.
In fact, NIOSH stands by its 1994 recommendations related to back belts, which are:
· There is little research on the effectiveness of back belts.
· The few studies that have addressed the effectiveness of back belts suffer from design flaws that render them unable to either prove or disprove the effectiveness of back belts.
· Most of the existing studies did not evaluate the type of industrial back belt that is most widely used.8
"The data are insufficient to conclude that industrial back belts reduce biomechanical loading of the trunk during manual lifting, including lifting patients," says Gardner, who specializes in research related to back injuries and the use of lumbar supports. "We don't recommend the use of back belts to prevent injury, and we don't consider back belts to be personal protective equipment. The reason is that we didn't find from the literature that back belts mitigate the hazards to workers caused by repeated lifting, pushing, or pulling."
Some evidence shows that back belts could cause slight increases in systolic blood pressure, he says, but "there's not enough evidence to conclude the changes are harmful. However, continuing research needs to be done."
Belts could cause'superman effect'
Other theoretical concerns are much harder to pin down, such as the "superman effect," Gardner adds. "People wear back belts and think they are supermen, so they may attempt outrageous lifts, but that's very hard to document."
Early next year, NIOSH plans to release the results of a four-year study in a major retail merchandise chain where the number of lifts performed is more hazardous than the weights lifted, Gardner says. Depending upon the study's results, the agency could revise its recommendations.
While NIOSH does not currently recommend back belt use, Gardner says voluntary use of belts in the workplace is acceptable, as long as managers don't require employees to wear them.
"If back belts are not being used, we don't recommend that they should be, but if the employer feels strongly about their use, all we can say is at least give employees the option of using them or not," he says.
Dillingham acknowledges that studies have not shown clearly whether routine back belt use industrywide prevents back pain, but "my own sense is that future studies will probably show a benefit," he says.
And in the meantime?
"There's really not a downside to using lumbar supports. They don't weaken the abdomen or the back, they may reduce some stresses on the back, and they may also remind workers to use proper lifting techniques," he states. "This is a controversy right now. As a scientist, I don't recommend them, but from a common-sense standpoint, I do. I use them in my yard."
References
1. Dillingham DR. Lumbar supports for prevention of low back pain in the workplace [Editorial]. JAMA 1998; 279:1,826-1,828.
2. Bigos S, Bowyer O, Braen G, et al. Acute Low Back Problems in Adults. Rockville, MD: Agency for Health Care Policy and Research, Public Health Service, U.S. Department of Health and Human Services; 1994.
3. van Poppel MNM, Koes BW, van der Ploeg T, et al. Lumbar supports and education for the prevention of low back pain in industry. JAMA 1998; 279:1,789-1,794.
4. Reddell CR, Congleton JJ, Huchingson RD, et al. An evaluation of a weightlifting belt and back injury prevention training class for airline baggage handlers. Applied Ergonomics 1992; 23:319-329.
5. Alexander A, Woolley SM, Bisesi M, et al. The effectiveness of back belts on occupational back injuries and worker perception. Professional Safety 1995; 10:22-26.
6. Walsh NE, Schwartz RK. The influence of prophylactic orthoses on abdominal strength and low back injury in the workplace. Am J Phys Med Rehabil 1990; 69:245-250.
7. Kraus JF, Brown KA, McArthur DL, et al. Reduction of acute low back injuries by use of back supports. Int J Occup Environ Health 1996; 2:264-273.
8. NIOSH Back Belt Working Group. Workplace Use of Back Belts: Review and Recommendations. Pub. No. 94-122. Rockville, MD: National Institute for Occupational Safety and Health; 1994.
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