title: Physical activity engendering loads from diverse directions augments the growing skeleton.
abstract: OBJECTIVE
  An experiment was conducted to determine if modifying habitual activities to involve mechanical loading from more diverse directions can enhance the growing skeleton.
  
  
  METHODS
  Growing female C57BL/6J mice were housed individually for 3 months in enclosures designed to accentuate either non-linear locomotion (diverse-orientation loading) or linear locomotion (stereotypic-orientation loading) (n=10/cage type). Behavioral assessments were performed daily to quantify cage activity level. Following the experiment, trabecular and cortical bone structure in the humeral head and distal femoral metaphysis were analyzed with μCT.
  
  
  RESULTS
  Throughout the experiment, groups did not differ in cage activity level. Yet, following the experiment, the proximal humeri of mice that experienced increased diverse-orientation loading had significantly greater trabecular bone volume fraction (p=0.004), greater cortical bone area (p=0.005), greater cortical area fraction (p=0.0007), and thicker cortices (p=0.002). No significant group differences were detected in the distal femoral metaphysis.
  
  
  CONCLUSIONS
  Diverting habitual activities to entail loading from more diverse orientations can augment the growing mouse skeleton. This study suggests that low-intensity activities that produce loads from diverse directions may represent a viable alternative to vigorous, high-impact exercise as a means of benefiting skeletal health during growth.
authors.affiliation: Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
authors.forename: I J
authors.initials: IJ
authors.lastname: Wallace
authors.forename: A T
authors.initials: AT
authors.lastname: Kwaczala
authors.forename: S
authors.initials: S
authors.lastname: Judex
authors.forename: B
authors.initials: B
authors.lastname: Demes
authors.forename: K J
authors.initials: KJ
authors.lastname: Carlson
mesh_terms: D000818:Animals; D001846:Bone Development / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000379:methods; D014057:Tomography, X-Ray Computed; D016474:Weight-Bearing / Q000502:physiology*