PREDICTIVE VALUE OF AGE OF WALKING FOR LATER MOTOR-PERFORMANCE IN CHILDREN WITH MENTAL-RETARDATION

The purpose of the present study was to clarify the predictive value o f age of walking for later motor performance in children with mental r etardation. While paying due attention to other factors, our investiga tion focused on the relationship between a subject's age of walking, a nd his or her subsequent beam-walking performance. The subjects were 8 5 children with mental retardation with an average age of 13 years and 3 months. Beam-walking performance was measured by a procedure develo ped by the authors. Five low beams (5 cm) which varied in width (12.5, 10, 7.5, 5 and 2.5 cm) were employed. The performance of subjects was scored from zero to five points according to the width of the beam th at they were able to walk without falling off. From the results of mul tiple regression analysis, three independent variables were found to b e significantly related to beam-walking performance. The age of walkin g was the most basic variable: partial correlation coefficient (PCC) = -45; standardized partial regression coefficient (SPRC) = -0.41. The next variable in importance was walking duration (PCC = 0.38; SPRC = 0 .31). The autism variable also contributed significantly (PCC = 0.28; SPRC = 0.22). Therefore, within the age range used in the present stud y, the age of walking in children with mental retardation was thought to have sufficient predictive value, even when the variables which mig ht have possibly affected their subsequent performance were taken into consideration; the earlier the age of walking, the better the beam-wa lking performance.