title: Relationships Between Age at Menarche, Walking Gait Base of Support, and Stance Phase Frontal Plane Knee Biomechanics in Adolescent Girls.
abstract: BACKGROUND
  Age at menarche impacts patterns of pubertal growth and skeletal development. These effects may carry over into variation in biomechanical profiles involved in sports-related traumatic and overuse knee injuries. The present study investigated whether age at menarche is a potential indicator of knee injury risk through its influence on knee biomechanics during normal walking.
  
  
  OBJECTIVE
  To test the hypothesis that earlier menarche is related to postpubertal biomechanical risk factors for knee injuries, including a wider, more immature gait base of support, and greater valgus knee angles and moments.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  University research facility.
  
  
  METHODS
  Healthy, postmenarcheal, adolescent girls.
  
  
  METHODS
  Age at menarche was obtained by recall questionnaire. Pubertal growth and anthropometric data were collected by using standard methods. Biomechanical data were taken from tests of walking gait at self-selected speed. Reflective marker position data were collected with a 3-dimensional quantitative motion analysis system, and 3 force plates recorded kinetic data.
  
  
  METHODS
  Age at menarche; growth and anthropometric measurements; base of support; static knee frontal plane angle; and dynamic knee frontal plane angles and moments during stance.
  
  
  RESULTS
  Earlier menarche was correlated significantly with abbreviated pubertal growth and postpubertal retention of immature traits, including a wider base of support. Earlier menarche and wider base of support were both correlated with more valgus static knee angles, more valgus knee abduction angles and moments at foot-strike, and a more valgus peak knee abduction angle during stance. Peak knee abduction moment during stance was not correlated with age at menarche or base of support.
  
  
  CONCLUSIONS
  Earlier menarche and its effects on growth are associated with retention of a relatively immature gait base of support and a tendency for static and dynamic valgus knee alignment. This biomechanical profile may put girls with earlier menarche at greater risk for sports-related knee injuries.
  
  
  METHODS
  Not applicable.
authors.affiliation: Lifespan Health Research Center, Department of Community Health and Department of Orthopaedic Surgery, Sports Medicine and Rehabilitation, Wright State University Boonshoft School of Medicine, 3171 Research Blvd, Kettering, OH 45420(∗). Electronic address: andrew.froehle@wright.edu.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Froehle
authors.affiliation: Department of Orthopaedic Surgery, University of California, San Francisco Fresno Medical Education and Research, Fresno, CA(†).
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Grannis
authors.affiliation: Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, Columbia, MO(‡).
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Sherwood
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of Missouri, Columbia, MO(§).
authors.forename: Dana L
authors.initials: DL
authors.lastname: Duren
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008572:Menarche / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012016:Reference Values; D011795:Surveys and Questionnaires