Working hands: Certain workplace exertions harm
muscles
very day, working Americans exert their muscles
in repetitive and forceful jobs. And as a result, work-related musculoskeletal
disorders in the United States annually account for nearly 70 million
physician office visits and cost more than $45 billion in compensation,
lost wages and lost productivity, according to the Institute of Medicine.
Professor Rob
Radwin is leading a research effort with Assistant Professor Walter
Block, Associate Professor Tom
Best and Assistant Scientist Mary
Sesto to investigate the physiological, anatomical and biomechanical
properties of muscles and tendons involved in repetitive manual work.
The research is supported in part by a three-year R01 grant from the
National Institute for Occupational Safety and Health, and by the MRI
scanner GE Medical Systems recently donated to the department.
One aspect of the group’s research includes
studying how equipment and power tools used in manufacturing plants
act on workers’ hands and arms. “Not only do people have
to produce forces to use these tools, but the tools produce rapidly
building forces as well,” says Radwin. “The tool operator
has to respond by contracting their muscles to prevent losing control.
Sometimes the tools are stronger than the operator, thereby stretching
the muscles.”
Recent studies show these muscle-lengthening contractions,
called eccentric exertions, might be harmful to muscles. In controlled
experiments, the researchers expose volunteers to eccentric exertions,
and using both mechanical means and MRI, measure changes in the muscles
and tendons.
The group already has found that even short-term repeated
exertions of this type result in muscle mechanics and MRI changes in
the lab. The researchers hope their results will show how exertions
in the workplace are involved in work-related disorders and ultimately,
how to prevent injuries.
