Variability in DDK rate productions in typically-developing children in Scotland

Diadochokinesis (DDK) skills are routinely assessed in clinical practice to evaluate potential motor involvement in a child’s speech difficulty. Research on the development of this skill in typically developing children shows a developmental trajectory of DDK rate, with an increased DDK rate and reduced variability in performance as children grow [1, 2, 3] . However, Williams & Stackhouse (2000) found in their cohort of 3-5-year-olds that while consistency of DDK productions improved with age, there was still considerable variability in the rate of DDK productions by age. Further, a review of several studies[4] established high variability in DDK productions within a larger range of age groups (2-17 years). The high level of variability reported for DDK rate warrants further research to better understand the role of variability in charting children’s developmental patterns for DDK performance.