2015 ISAKOS Biennial Congress ePoster #2611

Gender Differences in Dynamic Loading in Elite Athletes: Implications for Risk Assessment and Injury Prevention

Kenneth J. Hunt, MD, Aurora, CO UNITED STATES
Nathaniel Wilcox-Fogel, MS, Woodside, CA UNITED STATES
Rishi Trikha, BS, Palo Alto, CA UNITED STATES
Stanford University, Stanford, CA, USA

FDA Status Not Applicable

Summary: Body-mass adjusted peak and mean pressures are greater in the forefoot in female athletes compared to males, whereas male athletes exert significantly greater maximum force on the lateral foot during sports activities compared to females. Identification of biomechanical risk in individual athletes allows for early implementation of measures to prevent common sports injuries.

Abstract:

Introduction

Foot and ankle injuries account for significant missed time in elite athletes. A recent review of our institution’s injury database demonstrates that more than a quarter of all musculoskeletal injuries are foot/ankle injuries. In addition, there appears to be a significantly higher injury rate among female athletes compared to male athletes, particularly for bone stress injuries in the foot. This is consistent with previously reported differences in injury rates between genders. For example, metatarsal stress fractures are more common in women, whereas Jones fractures are much more common in male athletes. While some gender-specific risk factors have been reported, little is known about how dynamic loading of the foot during sports activities differs between men and women, potentially increasing risk of these injuries. We hypothesize that dynamic loading differences between genders during sports activities will correspond to the most common locations of stress injuries in the foot.

Methods

We recruited 106 healthy varsity athletes (89 male, 17 female) to participate. Dynamic foot loading data was collected using a validated wireless insole pressure measurement system during a series of athletic movements including running, jumping and cutting. Data was collected for contact area, maximum force, peak pressure, and maximum mean pressure at each of eleven foot regions during each athletic movement. Force and pressure data were normalized to body weight The averages between left and right foot were calculated for each variable and foot region in each athlete and paired t-tests were performed for gender group comparisons using commercially available statistical software. Significance was considered for p value less than 0.05.

Results

Male athletes displayed a significantly greater contact area compared to female athletes. Male athletes also demonstrated higher maximum force at the base of the fifth metatarsal. This included a 47% greater maximum force while jump-landing, a 47% greater maximum force while performing a jump-takeoff, a 27% greater maximum force during running, and a 23% greater maximum force during cutting. Conversely, female athletes showed higher pressures in the medial forefoot than male athletes. This included a 44% greater peak pressure and a 48% greater maximum mean pressure during running, and a 29% greater peak pressure and 44% greater maximum mean pressure during cutting.

Discussion/Conclusion:
Our findings suggest that body-mass adjusted dynamic loading patterns differ significantly between male and female athletes particularly in the midfoot and forefoot, during sports activities. These differences coincide with the locations of common stress injuries to the foot, suggesting significant biomechanical contribution to these frequent injuries. Modern sensor technologies used for wireless insoles can facilitate identification of risk factors in individual elite athletes. Identification of risk factors may play a role in preventive measures, including athlete education, modifications in footwear and individualized training regimens to prevent stress and overuse injuries in high level athletes.