title: Normal ranges of hip motion of infants between nine and 24 months of age.
abstract: The means and standard deviations were obtained for hip extension limitation, internal rotation, external rotation and abduction at nine, 12, 18 and 24 months of age from a sample of 86 normal, healthy children. Statistically significant changes were found for three of the four motions tested. Hip extension limitation decreased from 10 degrees at nine months to 3 degrees at 24 months. At nine months external rotation was greater than internal rotation in all cases, but with increasing age the mean values for the two motions began to approximate each other. There was a statistically significant positive correlation between infants with the greatest hip extension limitation and the degree of external rotation. There was also a significant negative correlation between the least hip extension limitation and greater abduction.
mesh_terms: D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D009068:Movement; D012016:Reference Values; D012737:Sex Factors