(Blacksburg, Va., Jan. 15, 2001) Among healthy people, muscle strength decreases by only about five percent between the ages of 25 and 40. But between the ages of 50 and 60, muscle strength decreases by about 20 percent.

To many of us this change is noticeable only while were working out at the gym or rearranging furniture, but its a matter of critical importance to the millions of aging workers in physically demanding jobs.

Its also important to Maury Nussbaum, assistant professor of industrial and systems engineering (ISE) at Virginia Tech, who has received a $425,000 grant from the National Institute of Occupational Safety and Health (NIOSH) to study the effects of age on work capacity. "Physically demanding work isnt going away," Nussbaum remarks. During the mid-1990s, he notes, about 12 percent of workers were over 55 years of age and that is expected to rise to 15 percent within five years. Many of these workers are doing the same sort of physical work from assembly-line jobs to heavy construction that they did in their 20s.

"By 2020, about 52 million people in the U.S. will be over 65," he notes. "Many workers are staying on the job longer, and many industries have increased the average age of workers doing physically demanding jobs. We need to learn what older workers are capable of doing during complex exertions."

Nussbaum works in ISEs Human Factors Engineering program. "I try to learn how the workplace affects workers and how to design workstations to maximize work capacity and minimize risk," he says.

Theres evidence of an intriguing twist to the fact that muscle strength is diminished with age, Nussbaum notes. As we age, we also develop more endurance. "Despite being weaker, older workers seem to have more resistance to fatigue," he says.

Muscles are composed of two types of fibers "fatigue-able" and fatigue-resistant. The fatigue-able fibers provide maximum strength or force, and we experience a selecti
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Contact: Maury Nussbaum
nussbaum@vt.edu
540-231-6053
Virginia Tech
14-Jan-2001