The Influence of Gender and Age on Hamstring Muscle Length in Healthy Adults

James W. Youdas, David A. Krause, John H. Hollman, William S. Harmsen, Edward Laskowski

DOI: 10.2519/jospt.2005.1428

Study Design: Cross-sectional descriptive study. Objectives: To examine the factors of gender and age, stratified by 10-year increments, on hamstring muscle length (HML) as measured by passive straight leg raise (PSLR) and popliteal angle (PA). Background: Differences in HML between men and women have not been examined for a large group of healthy adults over a wide range of ages. The usefulness of these data is to provide some typical values of HML for future reference. Methods and Measures: Two hundred fourteen adults (108 women, 106 men; age range, 20-79 years) with no known history of hip or knee joint disease and no history of recent hamstring strain participated in the study. PSLR (trunk-thigh angle) and PA (thigh-leg angle) were estimated with a goniometer. A 2-way analysis of variance (ANOVA) was used to analyze the effects of 2 independent variables (gender and age) on 2 dependent variables (PSLR and PA). Statistical significance was established at a<.05. Results: HML differed significantly (P<.001) between genders for both methods of measurement, with females demonstrating greater flexibility than their male counterparts. The difference between genders was 8° for PSLR and 11° for PA. HML was not influenced by age. Conclusions: This study provides physical therapists with typical values of HML in healthy men and women.

J Orthop Sports Phys Ther. 2005;35(4):246-252. doi:10.2519/jospt.2005.1428

Key Words: flexibility, hip extensors, lower extremity, straight-leg raise

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