Differences In Lower Extremity Anthropometric And Strength Measures In High School Male And Female Athletes

Abstract

Sex differences in anthropometric and physiologic parameters continue to be cited as risk factors associated with the increased frequency of anterior cruciate ligament injuries in females. PURPOSE: To compare selected lower extremity anthropometric and strength measures for differences between the sexes. METHODS: We recruited 22 female (age, 16.2 + 1.5 yrs; Tanner stage, 4.2 + 0.6, hgt, 167.7 + 5.9 cm, wgt, 60.0 + 5.3 kg) and 24 male (age, 16.5 + 1.3 yrs; Tanner stage, 4.7 + 0.6, hgt, 180.4. + 6.5 cm, wgt, 77.6 + 10.5 kg) high school varsity basketball and soccer players for this cross-sectional study. Selected anthropometric measures were obtained bilaterally from all participants: hip width, femur length, tibial length, standing quadriceps angle (SQA) and navicular drop. Isokinetic peak torque values for concentric (CON) and eccentric (ECC) hip abduction at 60 deg/s and 300 deg/s were obtained and normalized to Nm/kg body mass. Data were analyzed with a series of two-tailed t-tests for differences between the sexes (Bonferroni-adjusted alpha = 0.003). RESULTS: Females had greater SQA (12.7 + 3.4 deg vs. 8.1 + 2.4 deg, P < 0.0001) while males had greater average femur length (P < 0.0001) and tibial length (P < 0.0001). No sex differences were observed in navicular drop (P > 0.35) or ratio of femur length to tibial length (P > 0.67). None of the hip abductor isokinetic measures were different between the sexes, although males tended toward higher ECC peak torque values than females at 300 deg/s, 1.65 Nm/kg BM vs. 1.36 Nm/kg BM, respectively (P = 0.08). CONCLUSION: The absence of sex differences in foot pronation as measured by navicular drop was consistent with recent studies by Nguyen and Shultz (2007) and Hertel et al. (2004). We observed several significant differences in lower extremity anthropometric measures between the female and male high school varsity athletes; however, relationship of these differences to ACL injury risk remains to be determined. Supported by the John C. Erkkila, MD, Endowment for Health and Human Performance.