title: Distal radius geometry and skeletal strength indices after peripubertal artistic gymnastics.
abstract: Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON): were compared with girls exposed to gymnastics during growth (EX/GYM: ), using peripheral quantitative computed tomography (pQCT) to evaluate postmenarcheal bone geometry, density, and strength. Pre- and perimenarcheal gymnastic loading yields advantages in indices of postmenarcheal bone geometry and skeletal strength.
  
  
  BACKGROUND
  Two prior studies using pQCT have reported bone density and size advantages in Tanner I/II gymnasts, but none describe gymnasts' bone properties later in adolescence. The current study used pQCT to evaluate whether girls exposed to gymnastics during late childhood growth and perimenarcheal growth exhibited greater indices of distal radius geometry, density, and skeletal strength.
  
  
  METHODS
  Postmenarcheal subjects underwent 4% and 33% distal radius pQCT scans, yielding: 1) vBMD and cross-sectional areas (CSA) (total bone, compartments); 2) polar strength-strain index; 3) index of structural strength in axial compression. Output was compared for EX/GYM: vs. NON: , adjusting for gynecological age and stature (maturity and body size), reporting means, standard errors, and significance.
  
  
  RESULTS
  Sixteen postmenarcheal EX/GYM: (age 16.7 years; gynecological age 3.4 years) and 13 NON: (age 16.2 years; gynecological age 3.6 years) were evaluated. At both diaphysis and metaphysis, EX/GYM: exhibited greater CSA and bone strength indices than NON; EX/GYM: exhibited 79% larger intramedullary CSA than NON: (p < 0.05). EX/GYM: had significantly higher 4% trabecular vBMD; differences were not detected for 4% total vBMD and 33% cortical vBMD.
  
  
  CONCLUSIONS
  Following pre-/perimenarcheal gymnastic exposure, relative to nongymnasts, postmenarcheal EX/GYM: demonstrated greater indices of distal radius geometry and skeletal strength (metaphysis and diaphysis) with greater metaphyseal trabecular vBMD; larger intramedullary cavity size was particularly striking.
authors.affiliation: Department of Orthopedic Surgery, SUNY Upstate Medical University, Institute for Human Performance, 505 Irving Avenue, Rm 3206, Syracuse, NY 13210, USA. dowthwaj@upstate.edu
authors.forename: J N
authors.initials: JN
authors.lastname: Dowthwaite
authors.forename: T A
authors.initials: TA
authors.lastname: Scerpella
mesh_terms: D000293:Adolescent; D015519:Bone Density / Q000502:physiology; D016022:Case-Control Studies; D018483:Diaphyses / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D006173:Gymnastics / Q000502:physiology*; D006801:Humans; D011627:Puberty / Q000502:physiology*; D011884:Radius / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016474:Weight-Bearing / Q000502:physiology; D055815:Young Adult