October 5, 2006 Source: :
http://newsrelease.uwaterloo.ca/news.php?id=4782 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.
| 