title: Isokinetic muscle strength differences in patients with mucopolysaccharidosis I, II, and VI.
abstract: OBJECTIVE
  To determine muscular strength differences in patients with MPS-I, II, and VI versus age- and sex-matched healthy controls.
  
  
  METHODS
  Dominant leg isokinetic knee extension strength was measured at 90 and 120 degrees per second (d/s) using a dynamometer in 30 subjects with MPS and 42 controls (5-16 yrs). MPS-I was further divided into MPS-IA (attenuated) and MPS-IH (severe). Strength measures analyzed were peak torque (PkT), peak torque per unit body weight (PkT/BW) and per unit lean body mass (PkT/LBM), and average power (AP).
  
  
  RESULTS
  Following adjusting strength measures for age, MPS-IH and MPS-II had significantly lower strength measures for all variables at both angular velocities. MPS-VI had significantly lower PkT, PkT/LBM, and AP compared to controls at 90 and 120d/s. In contrast, MPS-IA was not significantly different from controls for any strength variable at either angular velocity.
  
  
  CONCLUSIONS
  The results of this study suggest that decrements in skeletal muscle strength depend on MPS diagnosis and severity of disease. Children with MPS-IH demonstrate the greatest difference in muscular strength compared to healthy controls.
authors.affiliation: School of Medicine and Public Health, University of Wisconsin, WI, USA.
authors.forename: Natalie E
authors.initials: NE
authors.lastname: Taylor
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, MN, USA Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Dengel
authors.affiliation: Division of Pediatric Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Troy C
authors.initials: TC
authors.lastname: Lund
authors.affiliation: Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Rudser
authors.affiliation: Division of Pediatric Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Orchard
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Steinberger
authors.affiliation: Division of Pediatric Genetics and Metabolism, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Chester B
authors.initials: CB
authors.lastname: Whitley
authors.affiliation: Division of Pediatric Endocrinology, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Lynda E
authors.initials: LE
authors.lastname: Polgreen
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000503:physiopathology; D008297:Male; D008059:Mucopolysaccharidosis I / Q000175:diagnosis / Q000503:physiopathology*; D016532:Mucopolysaccharidosis II / Q000175:diagnosis / Q000503:physiopathology*; D009087:Mucopolysaccharidosis VI / Q000175:diagnosis / Q000503:physiopathology*; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology*; D012720:Severity of Illness Index; D019415:Torque
keywords: Mucopolysaccharidosis; isokinetic; strength