title: Walking ability and its relationship to lower-extremity muscle strength in children with idiopathic inflammatory myopathies.
abstract: OBJECTIVE
  To describe gait deficits and their association with lower-extremity muscle strength in children with juvenile idiopathic inflammatory myopathies (IIM).
  
  
  METHODS
  Cross-sectional, descriptive study.
  
  
  METHODS
  Clinical research center.
  
  
  METHODS
  Consecutive sample of 25 ambulatory children diagnosed with juvenile IIM.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Manual muscle test (MMT) of bilateral hip flexor, extensor, and abductor; knee extensor; and ankle plantarflexor strength, all measured on a 0- to 10-point scale and summary strength measures. Video-based movement analysis to determine walking speed; gait cycle time; right and left step time; stride length; right and left step length; and stance, swing, and double-limb support phase durations.
  
  
  RESULTS
  Walking speed (1.03+/-0.27 m/s) was reduced because of shortened stride lengths (1.03+/-0.21 m) more than prolonged gait cycle times (1.05+/-0.22s). Walking speed highly correlated with the number of muscle groups weaker than grade 7 out of 10 (r=-.89) and the strength of the hip flexors (r=.85).
  
  
  CONCLUSIONS
  Lower-extremity strength measures, including MMT scores of individual muscle groups and the number of weak muscle groups, were predictive of gait limitations in children with juvenile IIM.
authors.affiliation: Rehabilitation Medicine Department, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA. karen_siegel@nih.gov
authors.forename: Karen
authors.initials: K
authors.lastname: Lohmann Siegel
authors.forename: Jeanne E
authors.initials: JE
authors.lastname: Hicks
authors.forename: Deloris E
authors.initials: DE
authors.lastname: Koziol
authors.forename: Lynn H
authors.initials: LH
authors.lastname: Gerber
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Rider
mesh_terms: D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D016014:Linear Models; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009220:Myositis / Q000503:physiopathology*; D016138:Walking / Q000502:physiology*