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Ingraham, S J.1; Serfass, R C. FACSM1; Walker, A J.1; Smiley, J1; Tews, K1; Chapman, R1

Medicine & Science in Sports & Exercise: May 2003 - Volume 35 - Issue 5 - p S245
E-24B Free Communication/Slide Gender Response to Physiological and Hormonal Changes

1University of Minnesota, Minneapolis, MN

(Sponsor: Robert C. Serfass, FACSM)

Female athletes experience a significantly greater number of non-contact anterior cruciate ligament (ACL), ankle and back injuries when compared with male athletes in similar sports. The physiological hormonal cycling in females has gained attention in establishing a relationship of the incidence of these injuries in female athletes with specific hormones, most notably estrogen and progesterone. Relaxin is a polypeptide hormone that has been previously associated with pregnancy; however relaxin is produced by the corpus luteum in non-pregnant normally menstruating females. Relaxin is known to alter collagen synthesis which reduces the intrinsic strength of connective tissue. PURPOSE: The purpose of this study was to determine if there was a relationship between the speculative cycling of relaxin, labeled as the menstrual cycle relaxin phase (MCRP) in normally menstruating females with new injury or pain.

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28 collegiate and post-collegiate Division III female track and field athletes completed daily training logs throughout their track and field season recording menstrual cycle, injury and pain. This group represented a total of 109 menstrual cycles and 2297 days of recorded data.

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Probability of new injury and pain by day were computed, which revealed trends of high and low risk of injury and pain through a 30-day cycle. Chi-square analysis revealed a statistically significant odds ratio of 1.49 and 1.31 for new injury and pain in the MCRP phase (p < 0.05).

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This evidence supports the hypothesis that exposure time within the MCRP will change a female athlete's risk for sustaining an orthopedic or musculoskeletal injury, potentially implicating relaxin as a causative agent.

©2003The American College of Sports Medicine