Clinical interpretation of "development of in-hand manipulation and relationship with activities".

OBJECTIVES This study examines the age-related increase of in-hand manipulation, the consistency of using a manipulation strategy, and the relationship between the frequency of in-hand manipulation and activities that typically require use of intrinsic hand control. METHOD Children (N = 184) between 2 years and 7 years of age were observed during selected activities that could elicit three forms of in-hand manipulation: rotation, finger-to-palm translation, and palm-to-finger translation. The child's use of a manipulation strategy was recorded. Activities that required manipulation of objects including a spoon, buttons, and crayons were also observed. RESULTS The study demonstrated that the frequency of two types of in-hand manipulation increases with age and illustrated the uneven nature of development of different types of in-hand manipulation. Even when the child had the ability, use of in-hand manipulation as a movement strategy was inconsistent. Small but significant relationships between in-hand manipulation skill and performance in selected activities were found when the effects of age were controlled. CONCLUSION On a practical level, the findings raise questions as to whether maturity of in-hand manipulation may be a factor limiting performance in the everyday activities of typically developing children.