Riley Brandt, University of Calgary
May 15, 2023
UCalgary researchers investigate why women are at higher risk of overuse injury
Although stress fractures are a common injury among physically active people, women are at two-to-four times higher risk than men. While the reasons for this difference in risk are not fully understood, bone shape or geometry and density are thought to be contributing factors.
Olivia Bruce, a PhD candidate in the Department of Biomedical Engineering, Schulich School of Engineering, and Dr. Brent Edwards, PhD, co-director of the Faculty of Kinesiology's Human Performance Lab, are working to understand how bone geometry and density affect stress-fracture risk in high-risk populations.
“We’ve known for a long time that women are at higher risk than men for stress fractures. In this work, we’re seeing how bone shape and density vary between men and women,” says Bruce. “Importantly, we’re also looking to see if those differences are actually meaningful, mechanically, for the development of stress fractures.”
To conduct her research, Bruce uses advanced medical imaging and statistical approaches to characterize how bone shape and density vary among young, active adults and between males and females. This data is then combined with computational models to determine how these variations affect stress-fracture risk. She says the Centre for Mobility and Joint Health in the McCaig Institute for Bone and Joint Health has been a great resource for the advanced medical imaging necessary for this work; results from the main study have been published in the journal, Bone.
“Our first generation of models suggested that females may have an increased risk of stress fracture because of subtle differences in their tibia [shin] bone geometry when compared to males,” says Edwards. “Female tibias are a bit narrower and have a thinner cortex than males, and this results in higher bone strain (deformation) during running. A really nice moment was when we developed the second generation of models on a completely new data set of females and males, and we found the exact same geometric differences.”
Stress fractures can take a minimum of 10 weeks to heal and sometimes require surgery to repair, which can be physically, financially and psychologically detrimental. People who get stress fractures are also more likely to fracture again in the future, making injury prevention critical. Understanding how bone geometry and density affect stress-fracture risk will help researchers develop screening tools, interventions, and more personalized training programs to reduce injury risk.
Another high-risk population for this type of injury is military personnel, making such research a critical need as stress fractures alone cost the American military more than US$100 million per year in medical costs and lost training time.
“We know there is really high incidence in these populations, but we don’t fully understand why,” says Bruce. “No one, surprisingly, has dug into the mechanics as to which 3D geometric features are specifically important.”
While bone shape and density are only two pieces of a larger puzzle, understanding how they affect stress-fracture risk and the disparity in risk between men and women will help researchers develop more effective injury-prevention and treatment strategies.
A related study by the researchers has been published in the journal, Computer Methods in Biomechanics and Biomedical Engineering.
The McCaig Institute for Bone and Joint Health
The McCaig Institute for Bone and Joint Health is comprised of basic scientists, orthopedic surgeons, rheumatologists, kinesiologists and biomedical engineers who research bone and joint diseases affecting more than six million Canadians. The McCaig Institute strives for early and accurate diagnosis, understanding of disease cause and progression, development of personalized treatments, prevention of bone and joint conditions and improvement of health care delivery in Alberta. The institute has over 80 faculty members, 80 staff members and 125 trainees at the University of Calgary and the University of Alberta. The McCaig Institute works closely with Alberta Health Services and the Alberta Bone and Joint Health Institute. Find more information
The Faculty of Kinesiology is the No. 1 ranked sport science school in North America and No. 11 globally. As a direct result of the 1988 Olympics, the faculty has developed a world-class environment for research and learning as well as built superb training facilities for coaches and athletes at the varsity, community and Olympic level. The faculty continues to have an impact by improving the health and mobility for all ages, from youth to older individuals and from recreation participants, elite athletes to Olympians, as well as those with disability and disease.
Brent Edwards is an associate professor in the Faculty of Kinesiology and Department of Biomedical Engineering at the Schulich School of Engineering and the Department of Clinical Neuroscience at the Cumming School of Medicine (CSM). He is also a member of the CSM’s McCaig Institute for Bone and Joint Health.