title: The influence of gender and age on hamstring muscle length in healthy adults.
abstract: METHODS
  Cross-sectional descriptive study.
  
  
  OBJECTIVE
  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
  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 alpha<.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 degrees for PSLR and 11 degrees for PA. HML was not influenced by age.
  
  
  CONCLUSIONS
  This study provides physical therapists with typical values of HML in healthy men and women.
authors.affiliation: Mayo Clinic College of Medicine, Rochester, MN 55905, USA. youdas.james@mayo.edu
authors.forename: James W
authors.initials: JW
authors.lastname: Youdas
authors.forename: David A
authors.initials: DA
authors.lastname: Krause
authors.forename: John H
authors.initials: JH
authors.lastname: Hollman
authors.forename: William S
authors.initials: WS
authors.lastname: Harmsen
authors.forename: Edward
authors.initials: E
authors.lastname: Laskowski
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007866:Leg / Q000033:anatomy & histology* / Q000502:physiology; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D012737:Sex Factors