U-M researchers seek to increase strength and mobility of the elderly

June 30, 2003
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ANN ARBOR—Many people find that as they grow older, the tasks they used to take for granted, like putting groceries away or lifting their grandchildren, become increasingly difficult. This happens because aging muscles lose their ability to generate both power and force.

A group of University of Michigan researchers is investigating ways to boost muscle power in the elderly. The project is funded in part by a three-year, $3.8 million grant from Michigan’s Life Sciences Corridor.

Headed by Bruce Carlson, director of the U-M Institute of Gerontology and a professor of cell and developmental biology, the team is exploring several approaches to strength building in human studies that began this spring.

Researchers are conducting two types of weight training over a 12-week period—one designed principally to build strength, the other designed to improve both strength and speed of movement. As the participants’ abilities increase, researchers boost the weight used so the training stays at the same percentage of their muscle capacity. For example, if lifting 40 pounds is 80 percent of a person’s ability at the start, as she becomes stronger, she might be able to lift 60 pounds with 80 percent of her muscle exertion. Before and after the training period, researchers take biopsies of thigh muscle to analyze strength and other characteristics of the muscle fiber.

Speed of movement is as important as the person’s strength because developing faster movement can help prevent certain types of falls among the elderly, Carlson said.

A key question is what kind of approach builds strength best. One of the ways the study will answer that is with the help of Neil Cole, president of Dexter-based Bio-Logic Engineering, which makes instrumentation to measure muscle power.

Researchers hope to build exercise programs that reduce the likelihood of falling and promote overall physical well-being and quality of life. Many people in the field of aging believe exercise is the key to better health and a more active lifestyle as people age.

The current group of study subjects includes 96 people ranging from their 20s to a group over 70.

Collaborating on the project are researchers from across U-M’s campus, each bringing a different expertise and approach. For example, Jeffrey Horowitz and Neil Alexander study how to make people stronger while James Ashton-Miller studies people’s gaits and the factors that lead to falling as they get older. Paul Cederna, a plastic surgeon, takes samples of muscle fibers and gives them to John Faulkner, a physiologist who analyzes the muscle samples at the individual fiber level.

Researchers are still seeking participants; Linda Nyquist is coordinating recruiting for the study. Contact her at (734) 936-6078.

In addition to Carlson and Cole, the team includes: Alexander, associate professor of geriatric medicine and associate research scientist with the Institute of Gerontology; Ashton-Miller, distinguished senior research scientist in mechanical engineering, biomedical engineering and Institute for Gerontology, and director of the Biomechanics Research Laboratory; Cederna, assistant professor of surgery and assistant research scientist with the Institute of Gerontology; Faulkner, professor of physiology and director of the Nathan Shock Center for Basic Biology on Aging at Institute of Gerontology; and Horowitz, assistant professor of kinesiology.