Age of Acquisition of Motor Abilities in Infants:

Abstract

Pediatric physical and occupational therapists rely on knowledge of the age of acquisition of motor abilities in infancy in order to identify those at-risk infants exhibiting delays. Sources of this knowledge include clinical authorities. The purpose of this paper is to evaluate the validity of the age of acquisition of specific motor abilities reported in two recently published clinical observation sources by comparing them with the data obtained systematically in the normative study of the Alberta Infant Motor Scale (AIMS). Overall, 43 percent of the AIMS items were reported to occur earlier in the clinical observation sources than were indicated by the normative data. The negative consequences associated with potential false positives when using one of these two clinical observation souces suggest that rehabilitation therapists use a norm-referenced, large sample test, such as the AIMS, when identifying infants who are delated in early motor development.