• A motor quotient was calculated by dividing the age of a child's best motor achievement by his or her chronologic age. A quotient less than 50 was said to predict gross motor delay (walking at or later than 24 months). Applying the quotient to 144 8- to 18-month-old children yielded a sensitivity of 87%, specificity of 89%, and overreferral and underreferral rates of 12%. By viewing motor development as a ratio, one is able to forecast motor delay.
Capute AJ, Shapiro BK. The Motor QuotientA Method for the Early Detection of Motor Delay. Am J Dis Child. 1985;139(9):940–942. doi:10.1001/archpedi.1985.02140110094038