Business groups are using a new study by the National Academy of Sciences as proof that the ergonomics rules approved by the Clinton administration in November should be overturned. However, science didn’t choose a side in this case, but revealed, as it so often does, that the question was more complex that anyone anticipated.

The Clinton policy, to begin in October, calls for broad new safety regulations to protect workers from musculoskeletal disorders (MSDs) – particularly back injuries and repetitive stress problems. These injuries, according to the study, cost the country $45 billion to $54 billion annually in lowered productivity and lost wages. They also result in an estimated 70 million annual visits to doctors.

However, as the chairman of the panel that conducted this study, Jeremiah A. Barondess, pointed out, “the connection between the workplace and these disorders is complex, partly because of the individual characteristics of the workers – such as age, gender and lifestyle.” Further, the study says, the nation lacks a uniform and comprehensive way to track MSDs and needs to create better definitions for these disorders.

For these reasons, groups such as the National Association of Manufacturers and the U.S. Chamber of Commerce, which strongly oppose the new rules, say the Bush administration should drop or at least dramatically reduce them. President Bush may have a different view of workplace safety than the previous administration, but he would have a hard time relying on this study for changing the Clinton directives.

Despite the recommended improvements to the nation’s worker-injury reporting, the study point to certain types of jobs that where ergonomics would make a significant difference in safety. Jobs where workers frequently lift materials while twisting their bodies, for instance, or jobs on heavy machinery or motor vehicles that cause whole-body vibration. But for the most frequent injury, there are also non-physical sources of pain. The study found that a rapid work pace, monotonous work, little decision-making power and high levels of stress were associated with back disorders.

These varieties of sources that contribute to injury make them hard to root out but important nonetheless. “Scientific evidence and industry data,” the study concludes, “strongly indicate that properly implemented strategies to reduce the incidence, severity, and consequences of work-related musculoskeletal disorders can be effective.” But employers and employees must take into account several possibilities beyond the immediate activity of a job and be highly committed to making changes.

The compromise between keeping and dumping the new rules is more study and more delay. The NAS study clearly suggests that this is not necessary, and rules that incorporate better definitions and more research would result in safer more productive workplaces nationwide.