Walking ability and its relationship to lower-extremity muscle strength in children with idiopathic inflammatory myopathies.
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.
Lohmann Siegel
Karen
K
Rehabilitation Medicine Department, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA. karen_siegel@nih.gov
Hicks
Jeanne E
JE
Koziol
Deloris E
DE
Gerber
Lynn H
LH
Rider
Lisa G
LG
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*