The effect of anatomic variation on the risk of overuse injuries has not been adequately evaluated. To determine the association of several common anatomic characteristics (genu varum, genu valgum, genu recurvatum, and lower limb length differences) with risk of overuse injury, we made prospective morphologic measurements of young men prior to beginning 12 wk of Army infantry training. The training included frequent running, marching, calisthenics, and other vigorous activities. Lower extremity anatomic landmarks were highlighted, and front- and side-view photographic slides were taken of the 294 study volunteers. The slides were computer digitized, and the following measures calculated: pelvic width to knee width ratio (to assess genu valgum/varum), quadriceps angle (Q-angle), knee angle at full extension, and lower limb length differences. The cumulative incidence of lower limb overuse injury was 30%. Relative risk (RR) of overuse injury was significantly higher among participants with the most valgus knees (RR = 1.9). Those with Q-angle of more than 15° had significantly increased risk specifically for stress fractures (RR = 5.4). Anatomic characteristics were associated with several other types of injuries, including pain and nonacute muscle strain due to overuse. This pilot study provides evidence that some lower limb morphologic characteristics may place individuals at increased risk of overuse injuries.
Walter Reed Army Institute of Research, Washington, DC; U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD; Army Research Institute of Environmental Medicine, Natick, MA; and Walter Reed Army Medical Center, Washington, DC
Submitted for publication September 1995.
Accepted for publication April 1996.
The authors thank Wendy Robinson Weringo, formerly of ARIEM, for valuable assistance with all aspects of conducting this study and Drs. Robert Tuthill and Anne Stoddard of the University of Massachusetts School of Public Health for guidance in study design and analysis. Both Dr. Wayne Leadbetter of the Orthopaedic Center, Rockville, MD, and Dr. William J. Hopkinson, Associate Professor in the Department of Orthopaedic Surgery, Loyola University Stritch School of Medicine, provided careful review and helpful comments. We also thank the soldiers who volunteered their participation, without whose cooperation this study would not have been possible.
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