title: Side-to-side differences in bone strength in master jumpers and sprinters.
abstract: BACKGROUND
  This study evaluated side-to-side difference in tibial bone structure, calf muscle cross-sectional area (CSA) and hopping force in master athletes as a result of training for sports with different magnitudes of inter-leg loading difference.
  
  
  METHODS
  Tibial bone parameters (at 4%, 14%, 38% and 66% tibial length proximal to distal end), muscle CSA (at 66% tibial length) and hopping forces of both legs of 51 master athletes (conditioned jumpers, conditioned triple jumpers, unconditioned jumpers, hurdlers and sprinters) were examined using pQCT. In epiphyseal 4% slice bone CSA (Ar.tot), total BMC (vBMC.tot), trabecular BMC (vBMC.tb) cortical BMC (vBMC.ct), and trabecular BMD (vBMD.tb) were measured. In diaphyseal slices, Ar.tot, vBMC.ct, cortical density (vBMD.ct), cross-sectional moment of inertia (CSMI) and calf muscle CSA (MuscA) were examined.
  
  
  RESULTS
  In conditioned jumpers, side-to-side differences in favour of take-off leg were found in 4% slice in vBMC.tb (+4.1%) (P<0.05). A side-to-side difference was found in 66% slice vBMC.ct and CSMI (both P<0.05), with conditioned jumper (+2.8% and 6.6%) and triple jumper (+2.7% and 7.2%) values higher than other groups.
  
  
  CONCLUSIONS
  The results suggest that regular training in high-impact sports with uneven lower limb loading results in side-to-side differences in skeletal adaptation independent of age and gender, suggesting that high-impact exercise is effective in maintaining bone strength throughout human lifespan.
authors: Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Manchester, United Kingdom. a.ireland@mmu.ac.uk
authors: A
authors: A
authors: Ireland
authors: M
authors: M
authors: Korhonen
authors: A
authors: A
authors: Heinonen
authors: H
authors: H
authors: Suominen
authors: C
authors: C
authors: Baur
authors: S
authors: S
authors: Stevens
authors: H
authors: H
authors: Degens
authors: J
authors: J
authors: Rittweger
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D056352:Athletes; D015519:Bone Density; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000502:physiology; D011859:Radiography; D013177:Sports / Q000502:physiology*; D013977:Tibia / Q000000981:diagnostic imaging* / Q000502:physiology