You asked if scientific data confirmed that ergonomic adjustments in the workplace could reduce injuries caused by repetitive motion.

SUMMARY

A large body of research confirms a relationship between repetitive motion in workplace settings and injuries. But there seems to be less scientific support for specific ergonomic designs to mitigate injuries.

A 1997 report from the National Institute for Occupational Safety and Health (NIOSH) of the Centers for Disease Control and Prevention (CDC) synthesized the results of over 600 scientific articles about ergonomics, and identified 6,000 articles about the subject. NIOSH acknowledged that the relationship between musculoskeletal disorders (MSDs) and the workplace was debatable. Yet it concluded that “a large body of credible epidemiologic research exists that shows a consistent relationship between MSDs and certain physical factors, especially at higher exposure levels. ” NIOSH recommended that all workplaces have a comprehensive ergonomics program in place to protect workers, based on both the prevalence of work-related injuries and the effectiveness of intervention.

Insurance companies also study the use of ergonomics to prevent workplace injuries. For example, Liberty Mutual Insurance Company founded the Research Institute for Safety in 1954 to develop methods for creating safer workplaces. Liberty Mutual's website ranks ergonomic research as one of its “top ten” innovations over the past half-century (www. libertymutual. com). Its researchers have found that repetitive motion injuries—which the insurer estimates cost companies $ 2. 7 billion in 2000 in medical and wage-replacement costs—can be prevented by identifying and remedying poor ergonomics in the workplace. They recommend attaching sensors to hand tools like knives, pliers, and screwdrivers to track their use. Employers can use this data to determine if workers are improperly using the equipment, or if the equipment needs to be replaced by tools that would allow workers to perform their jobs with less effort.

Dow Chemical Company adopted this methodology to address ergonomic injuries in its design unit (see “Ergonomics Case Study: The Dow Chemical Company's Use of the "Six Sigma" Methodology,” (2004) http: //www. osha-slc. gov/dcsp). Because this department's employees spent most of their time at computer keyboards, Dow was concerned that they were susceptible to injuries. The company implemented a four-step plan to measure the potential for injury, analyze the sources of the problem, improve the situation, and control for future problems. The study resulted in a decline in the number of severe ergonomic injuries.

Some researchers argue that employees who complain of musculoskeletal pain often do not suffer from an underlying pathology, such as carpal tunnel syndrome, but condition themselves to believe they have an illness. These researchers believe that most employee discomfort results from fatigue and overuse and not from actual disability. They argue that the disability is generally self-diagnosed and reflects cultural and social expectations about the dangers of repetitive labor.

However, much research refutes these claims. Even in an office setting, where it can be harder to document the causes of musculoskeletal pain, researchers have linked the use of video display terminals (VDTs) and workplace injuries. NIOSH has conducted several dozen health hazard evaluations and published more than 50 scientific reports on the health risks of VDTs. One NIOSH study showed that typing time and speed are “significant predictors” of pain in the back and shoulders. Another NIOSH study demonstrated a relationship between typing speed and hand and wrist disorders among newspaper workers (See “Occupational Health Aspects of Work with Video Display Terminals,” (1998) http: //www. cdc. gov/niosh/pdfs/99-135. pdf).

While most researchers agree that poor ergonomics can lead to injury, they disagree on the best way to redesign workplaces to make them safer. For example, NIOSH found that the dangers of keyboard use may not be mitigated by substituting so-called alternative keyboards. It cited other factors that influence comfort, including the placement of equipment and work material, lighting, chair adjustability, and the organization of the workday.

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