title: Bone strength and muscle properties in postmenopausal women with and without a recent distal radius fracture.
abstract: Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk.
  
  
  BACKGROUND
  The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF.
  
  
  METHODS
  One hundred sixty-six postmenopausal women (50-78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6-24 months (Fx, n = 32) and without fracture (NFx, n = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSIc) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA).
  
  
  RESULTS
  There was a significant group difference (p < 0.05) for the forearm and lower leg, with the Fx group demonstrating 16 and 19% lower BSIc, 3 and 6% lower muscle density, and 20 and 21% lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures.
  
  
  CONCLUSIONS
  Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.
authors.affiliation: School of Physical Therapy, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada. katie.crockett@usask.ca.
authors.forename: K
authors.initials: K
authors.lastname: Crockett
authors.affiliation: School of Physical Therapy, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: C M
authors.initials: CM
authors.lastname: Arnold
authors.affiliation: College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Farthing
authors.affiliation: College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: P D
authors.initials: PD
authors.lastname: Chilibeck
authors.affiliation: Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Johnston
authors.affiliation: School of Physical Therapy, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Bath
authors.affiliation: College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: A D G
authors.initials: AD
authors.lastname: Baxter-Jones
authors.affiliation: College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada. saija.kontulainen@usask.ca.
authors.forename: S A
authors.initials: SA
authors.lastname: Kontulainen
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D000886:Anthropometry / Q000379:methods; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D006801:Humans; D008019:Life Style; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D015663:Osteoporosis, Postmenopausal / Q000473:pathology / Q000503:physiopathology; D058866:Osteoporotic Fractures / Q000473:pathology / Q000503:physiopathology*; D017698:Postmenopause / Q000502:physiology; D011885:Radius Fractures / Q000473:pathology / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014954:Wrist Injuries / Q000473:pathology / Q000503:physiopathology*
keywords: Distal radius fracture; Dual-energy x-ray absorptiometry (DXA); Musculoskeletal properties; Peripheral quantitative computed tomography (pQCT)