FACTORS AFFECTING AGE OF WALKING BY CHILDREN WITH MENTAL-RETARDATION

The relationship between age of walking and two factors of severity of intellectual disability and clinical types (autism, Down syndrome, ep ilepsy, and ''residual'') in children with mental retardation was inve stigated. Subjects were 118 children whose disabilities ranged from se vere to mild. Measures by clinical type were significant, and the diff erences of any two clinical types excepts between children with epilep sy and the ''residual'' group were significant, but severity of intell ectual disability was not significant. Most children with autism (27 s ubjects, 93%) walked by the normal time limit of 18 months. Only 3 chi ldren (11%) with Down syndrome began to walk within that limit, and 9 of them (33%) walked after 2 years of age. In the ''residual'' group ( including children with epilepsy), 37 children (60%) walked within the normal limit but 15 (25%) only after 2 years of age.