title: Bone properties and muscle strength of young haemophilia patients.
abstract: OBJECTIVE
  To evaluate bone properties, muscle strength and the relationship between the two, in young (7.0-17.7 years) haemophilia patients (h) and healthy boys (c).
  
  
  METHODS
  Twenty-seven boys with severe haemophilia and 33 healthy boys, of similar age, body mass, height, (mean +/- sd for h and c, respectively: 11.2 +/- 3.2 vs. 11.4 +/- 2.9 years, 42.6 +/- 16.6 vs. 41.6 +/- 17.3 kg, 145 +/- 18 vs. 146 +/- 17 cm) and pubertal stage according to secondary sex characteristics, volunteered for the study. all subjects were physically inactive (as determined by questionnaire).
  
  
  METHODS
  Subjects performed isokinetic elbow and knee extension and flexion tests at two angular velocities (biodex system ii dynamometer). Bone properties were evaluated by qualitative ultrasound (sunlight omnisense), at the distal radius and tibial mid-shaft. H subjects received prophylactic factor viii treatment within the 24 h preceding testing. No test was performed in the presence of haemorrhage.
  
  
  RESULTS
  Muscle strength was consistently higher in c compared with h, especially in the lower limbs (e.g. knee extension: 1.80 +/- 0.44 vs 1.48 +/- 0.53 N x m x kg(-1) body mass, respectively, p = 0.01). No differences were observed in tibial or radial speed of sound between groups. Correlations between muscle strength and bone properties were observed only in the lower limbs and only in c (r = 0.37-0.48).
  
  
  CONCLUSIONS
  Muscle strength, especially lower limbs' strength, was lower in haemophilia patients compared with a matched, similarly inactive population of healthy boys. Nevertheless, at this age range, this relative weakness is not associated with inferior bone properties.
authors: Ribstein Center for Sport Medicine Sciences and Research, Wingate Institute, Israel. bareket.falk@brocku.ca
authors: B
authors: B
authors: Falk
authors: S
authors: S
authors: Portal
authors: R
authors: R
authors: Tiktinsky
authors: L
authors: L
authors: Zigel
authors: Y
authors: Y
authors: Weinstein
authors: N
authors: N
authors: Constantini
authors: G
authors: G
authors: Kenet
authors: A
authors: A
authors: Eliakim
authors: U
authors: U
authors: Martinowitz
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D002648:Child; D004550:Elbow; D015444:Exercise / Q000502:physiology; D006467:Hemophilia A / Q000503:physiopathology*; D006801:Humans; D007717:Knee; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011884:Radius / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013977:Tibia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography