Foot morphologic characteristics and risk of exercise-related injury.

OBJECTIVE: It is widely accepted that persons with flat or high-arched feet are at increased risk of exercise-associated injury, even though this purported association has not been scientifically evaluated. We evaluate the risk of exercise-associated injury among young men with flat, normal, and high-arched feet.
DESIGN: A prospective study of 246 US Army Infantry trainees followed up over a rigorous 12-week training program. All subjects were evaluated prior to onset of training. Evaluation included photographs of the right, weight-bearing foot that were digitized and utilized to make several measures of arch height.
SETTING: An army initial entry training center.
SUBJECTS: All trainees beginning army training on 2 successive weeks were potential volunteers. There were no criteria for exclusion other than declining to participate (n = 3). The subjects were healthy, active young men with a mean age of 20.3 years. OUTCOME MEASURE: The occurrence of a lower-extremity musculoskeletal injury resulting in a visit to and a diagnosis by an army physician or physician assistant. Treating physicians and physician assistants were blind to participation status and were not study staff members.
RESULTS: On univariate analysis, there was an association between arch height and risk of injury using several alternative operational definitions of foot type. The 20% with the flattest feet were at the lowest risk (reference group; odds ratio, 1.0), with adjusted odds ratios for any musculoskeletal injury of 3.0 (P < .05) for the middle 60% group and 6.1 (P < .05) for the highest 20% group.
CONCLUSIONS: These findings do not support the hypothesis that low-arched individuals are at increased risk of injury, and they have implications for runners, exercise enthusiasts, and clinicians. It may be possible to prevent substantial morbidity among active populations by identifying individuals at high risk and advising alternate activities.