With this assessment device, Dr. Scott MacKinnon (R) is able to assess the possible risks for overexertion injuries to the lower back associated with a manual materials handling task.

Two persons do the same job for 20 years in equal environments and one person ends up with debilitating back pain while the other is fine.

That’s the sort of puzzle that intrigues Dr. Scott MacKinnon, Memorial’s first Research Chair in Workplace Health and Safety. As part of the SafetyNet research program, his job is to spearhead interdisciplinary research initiatives in the area of workplace health and safety.

“Currently we have a regulatory environment which tries to set limits for workplace demands – for example, using protective equipment when noise exceeds certain limits.”

The problem with that approach, said Dr. MacKinnon, is that it can’t be used for manual materials handling tasks because we are far from knowing what exposures cause injury. “We have manual handling guidelines for the amount of load and where that load can be moved within a workstation. While these guidelines provide a good screening device, they are not discriminate enough to use as a model to relate an injury to the task.”

In reality, many workers can perform tasks without getting hurt even when they do not precisely follow guidelines. “So we’re slowly changing the way we understand the relationship between work practices and risk for injury and accident.”

Dr. MacKinnon said there are two types of injuries – acute and chronic. An acute injury, such as slipping on a puddle of water and wrenching your back, is generally related to poor housekeeping practices. “But the more insidious injuries, the ones with the higher cost to the healthcare system, are chronic injuries that evolve over time.”

Chronic injuries are difficult to prevent, predict and regulate from a legislative perspective. “Once people present with substantial demonstration of pain, for example from carpal tunnel syndrome, they may never be able to return to the job that they were doing.”

Dr. MacKinnon said his new job, in cooperation with other SafetyNet researchers, is to bring all the stakeholders together and look at issues related to workplace health and safety. “In a best practices model, everyone has to put their best foot forward. Employers must have the proper safety regulations in effect, but employees have to be educated enough to recognize risk and mediate that risk. That may mean refusing to do a certain task if they do not feel they can do it safely.”

The direct cost of an injury or accident is pretty straightforward but indirect costs creep into the system. Indirect costs include replacing an injured worker, increased management time for that employee, lower productivity, and perhaps lower quality of production. “For every dollar we spend in direct cost for injuries there’s at least $6 in indirect cost,” said Dr. MacKinnon. “It’s detrimental to the economy.”

Dr. MacKinnon’s background research gives him a good basis to approach his new interdisciplinary task. He has expertise in the analysis of human movement, including assessment of low back fatigue and pain; the development of operations guidelines for heavy materials handling activities and the cost-benefit analyses of ergonomic intervention programs. He has recently been investigating the influences of platform motion on injury, postural stability, motion sickness and fatigue on command and control in harsh maritime environments.

For more on the Research Chair in Workplace Health and Safety, see www.safetynet.mun.ca/researchChair.htm.