News Release

2006-10-05 10:28:37

UW digital ergonomics research seeks to make workplaces safer

WATERLOO, Ont. (Thursday, Oct. 5, 2006) -- Innovative digital ergonomics research led by a University of Waterloo faculty member aims to make workplaces safer by eliminating a common injury -- shoulder strain.

By combining computer technologies, such as digital human modelling, together with laboratory experiments, Clark Dickerson and his research team are working toward reducing the risks or stresses involved in jobs even before the workplaces are built.

As a result, the research should ultimately lead to better health among employees and lower injury compensation costs.

Dickerson, a professor of kinesiology, has been awarded a grant from the Canadian Foundation for Innovation to advance research in digital ergonomics aimed at preventing shoulder injuries on the job.

His project, entitled Enabling Advanced Digital Ergonomics and Shoulder Biomechanics Research, has a total budget of $470,630, with $178,035 from CFI's leaders opportunity fund and the remainder from provincial and industry sources.

Dickerson's team investigates how to prevent musculoskeletal disorders in the workplace. These pathologies, caused by exposure to stressful work conditions, represent more than $100 billion in annual costs to society. Commonly injured areas of the body include the low back, wrists and shoulder.

"My research focuses on identifying, quantifying and reducing work-related stresses in the shoulder through mathematical modelling and experimentation," said Dickerson, who earned his PHD in biomedical engineering at the University of Michigan, in Ann Arbor.

Dickerson said his work provides computerized design tools and enables insights into the impact of human body movements, including muscle activity in the shoulders, arms and hands.

"These can then be used together to improve the safety and usability of workspaces and other man-machine interfaces, thereby reducing the frequency and severity of occupational shoulder injuries," he said.

His research team studies typical tasks at work, including dynamic movements with force and precision requirements. To quantify the impact of such tasks on the shoulder, researchers develop several biomechanical computer models and then evaluate the models through experiments.

The team uses a dynamic model of the upper limb to calculate joint torques and forces. Then, a computer model of the internal shoulder geometry reconstructs the underlying musculoskeletal structure. That model establishes the line-of-action of each muscle, as well as the positions and orientations of each bone.

"This model calculates the instantaneous orientations of 38 muscle elements while respecting orthopedic obstacles using geodesic conventions," Dickerson said.

Another computer model balances the forces and torques created by external loads through distributing muscular demand with an optimization approach, which also estimates specific tissue stresses. Yet another model describes a mathematical formulation of physical efforts.

In the lab, experiments are conducted with human subjects to monitor movement, muscle activity, work perception and hand forces. Afterward, the results of the computer models are compared with the empirical data.

"The primary purpose of our approach is to enable informed prospective job design," Dickerson said, explaining that integration of computer models with existing software allows simulated future jobs to be analyzed for potentially injurious stresses to shoulder tissues.

"Simply put, we want to increase the comfort of workers and decrease the effort in the shoulder when they perform their work, and we would like to do so before they are exposed to potentially harmful work environments," he said.

Resources

Contacts:

Clark Dickerson, professor of kinesiology, 519-888-4567 ext. 37844 or
cdickers@uwaterloo.ca

John Morris, UW media relations, 519-888-4435 or jmorris@uwaterloo.ca

University of Waterloo release no. 116

2006-10-05 10:28:37