Back Belts in the Workplace

In this issue of THE JOURNAL, Wassell and colleagues¹ present the results of a prospective cohort study evaluating the potential benefits to workers who wear back belts when handling materials. They discern none. Not only of interest to workplace, health, and safety policymaker, the article offers lessons to those interested in regional backache. The science is noteworthy as is the social construct it serves. When regional backache thwarts physical performance, should the task(s) be viewed as hazardous and the worker injured?

In assessing the effectiveness of an intervention, cohort studies are often considered inferior to randomized controlled trials (RCTs). Therefore, since an RCT published in THE JOURNAL 2 years ago² showed that wearing back belts for 6 months afforded no advantage to airline baggage handlers, why publish a cohort study? It is possible that workers who choose to wear belts may be at different risk for back pain in ways that the previous investigators could not identify. If a worker finds a health intervention unacceptable, that intervention cannot benefit that worker. The study by Wassell et al is thus a test of the effectiveness of back belts among workers who choose to wear them and is a design most likely to identify a benefit, if one is present. Management, labor, and government are testing, rather than contesting, their preconceived notions at some expense and risk. The informed consent requires management to donate the cost of the time involved in worker assessment. The workforce is to consider volunteering. Regulators are subjugating inference and consensus regarding ergonomic remedies to establish effectiveness.

In the study by Wassell et al, approximately 9000 workers at 160 retail sites comprised the population at risk. At some sites, the use of back belts was required; at others it was voluntary. About two thirds of the workers in the stores with the first policy reported nearly daily use of a back belt; about a third of the workforce did so when offered the back belt as an option. There were 2 main health outcomes: the likelihood after 6 months of recalling 1 or more episodes of back pain and the likelihood of filing workers' compensation claims for back injury. The incidence of either outcome was no different between the 2 groups, regardless of the store policy or the magnitude of physical demand of the job. The findings suggest that back belts should be viewed as no more than an option in apparel. Furthermore, any recommendation to wear back belts when exposed to tasks with this range of physical demand should be met with skepticism; the burden of proof should be on those who might still advocate them.

The lack of prophylactic benefit of back belts may seem counter-intuitive. Shouldn't the lumbar lordosis be bolstered when lifting? This rationale has long been questionable on biomechanical grounds. It has been difficult to demonstrate that back belts influence paraspinous muscle force or fatigue.^{3 - 4} Although it is possible to inflate a back corset so that in vivo intradiskal pressure is diminished, the corset must be inflated to the limit of comfort.⁵ Yet, back belts and other unproved remedies abound in workplaces. All this is driven by the social construction that underlies the 2 health outcomes assessed in the study by Wassell et al: What is it that renders backache memorable? What is it that renders backache compensable?

It has taken more than 2 decades for the entrenched common wisdom to yield to the systematic test of science. Unfortunately, it can take as long or longer for the superseding inferences to inform the common wisdom in the workplace and the physician's office. The belief that the principal reason most episodes of backache are recalled is related to their severity and the belief that the reason a worker finds an episode of regional backache incapacitating relates to the magnitude of injury both need to be discounted.⁶ Regional musculoskeletal disorders afflict otherwise well working-aged adults who have had no physical exposure unusual for them.⁷ Whether occurring during work or off hours, back pain seldom results from a fall, direct impact, or extraordinary physical demands. In these instances, an injury has occurred. Efforts to render workplaces and other environments safe should be encouraged. For instance, some remedies involve workplace modifications such as using mechanical aids for lifting or redesigning tasks. Are such efforts relevant to regional musculoskeletal disorders?

Regional low back pain is a ubiquitous intermittent and remittent predicament of life. Surveys in many countries have shown that 11% to 45% (depending on the definition of back pain) of adults experience an episode each year, and most people with back pain can expect recurrences.^{8 - 9} Regional back pain is exacerbated mechanically, thereby rendering many activities of daily living a challenge. Backache is never trivial and, when present, can be as incapacitating as many ailments, including congestive heart failure and renal insufficiency.¹⁰

It remains unclear whether certain subsets of individuals, based on genetic predisposition or environmental influence, are more or less likely to experience morbidity associated with back pain. Regardless, the experience profoundly depends on whether the individual has the ability to cope with the episode. It is unusual for coping to be thwarted solely by the magnitude of pain. However, the pain is enhanced if an individual cannot readily find a way and a reason to get on with life despite the compromise in physical capacity. Back pain that is enhanced in this fashion is more memorable and more likely to stimulate seeking "care" in the medical system.^{11 - 12} However, the need also to seek caring is seldom realized; empathy and consideration of alternatives for coping at home and at work are the foundation on which to base the therapeutic contract.

If coping is thwarted in the workplace and results in work incapacity, the ready recourse is to the care indemnified by workers' compensation insurance. Access to workers' compensation requires that the back pain arose out of and in the course of employment and by "accident." If so, medical care, rehabilitation, short-term wage loss, and future income loss consequent to permanent disability are compensable. This recourse has been available since regional backache was deemed an "injury" some 70 years ago.^{13 - 14} Common wisdom holds that incapacitating regional backache must have arisen out of and in the course of the work for which physical capacity is compromised. It follows that an "accident" has occurred and the consequence is a back injury. However, simply because a particular biomechanical challenge exacerbates back pain does not mean that such usage is the proximate or principal cause. By analogy, although stair climbing can exacerbate angina it would not be logical to infer that stair climbing causes coronary artery disease, to countenance a construct such as "stair climbers chest," or to replace stairs with escalators as a public health measure. However, backache and other regional musculoskeletal disorders have been viewed this way and continue to be so despite studies such as an RCT that found providing biomechanically oriented training to postal workers had no effect on the incidence of memorable or disabling back pain.¹⁵

The article by Wassell et al also includes economic assertions regarding the costs of back pain that are reiterated throughout the literature on back injuries.¹⁶ However, the human cost also must be considered. The social construction of ascribing disabling regional back pain to an injury is potentially iatrogenic and likely to have lasting effects on the individual's sense of invincibility.⁶ Furthermore, the perpetuation of this social construction has impeded attempts at reform. In the past decade, a considerable scientific literature has accumulated probing the influences of both the physical demands of tasks and the psychosocial context of work on the likelihood of finding a backache incapacitating. The evidence for the major role of the latter is substantial.^{17 - 18} Multiple psychosocial aspects of life in the workplace can prove challenging. Many relate to interpersonal relationships, a sense of being valued, autonomy and security on the job, and management styles. Whenever the context of work is personally challenging, coping with the next backache will be confounded. It is no wonder that in addition to the lack of benefit from back belts, Wassell et al could show that job dissatisfaction and prior workers' compensation claims were associated with memorable and compensable backache. The challenge is to fashion employment that is comfortable when workers are well and accommodating when they are ill or incapacitated, including those with regional back pain.

It is time to relegate back belts and other such physical adaptations to the realm of design, not safety. Moreover, it is time to focus on the psychosocial elements of life, on and off the job, that render too much of back pain so intolerable that it is memorable and even incapacitating. Therein lie potentially effective remedies to one of the most pressing public health issues facing industrialized countries.¹⁹