Putting Bones to the Test - why female soldiers fracture their tibia more often than men

American Fitness, Jan, 2001

The U.S. Army is investigating the reason female soldiers suffer fractures along the tibia at twice the rate of their male counterparts. They are concerned because not only are stress fractures costly, they disable service personnel, thus compromising military readiness. To combat this problem, the Army is teaming up with researchers at Virginia Tech to study the effects of specialized exercises on young women's bones.

"During my tenure here, I don't think there has ever been a funded human exercise research project of this magnitude," says Bill Herbert, professor in the Department of Human Nutrition, Foods and Exercise and primary investigator on this project. "What really made this grant a success was our ability to assemble a very talented multidisciplinary team [with] the capacity to combine expertise in exercise physiology, nutrition, bone physiology and statistics. In addition, we have had invaluable collaboration from long-term colleagues in the local medical community."

The study will observe 160 women between the ages of 18 and 26 and observe the effects of 30 weeks of isokinetic resistance exercise on their non-dominant arms and legs by using the Biodex[R] exercise machine. A Mechanical Response Tissue Analyzer (MRTA) will gauge the stiffness of the arm and leg bones. The MRTA, one of a limited number of such machines in the world, will monitor changes in the shape of the bone using vibrations and sensors to measure the entire tibia or ulna. Participants will also have bone density and lean/fat mass measured by a DXA machine, a high-tech body scanner. While this work has important implications for reducing stress fractures, it also has long-term potential of preserving bone mass and preventing osteoporosis. For more information, visit www.tibial.ed.vt.edu.