Influence of dysgraphia on kinematic characteristics of handwriting in Italian primary school children

Handwriting is a complex skill that improves with schooling and it is accomplished after the child has achieved and integrated underlying perceptual-motor performance components. Even though nowadays children are expected to acquire a level of handwriting proficiency, even on the first day of school, at least 27% of the school population has difficulty with handwriting and needs to be screened for (with) an intervention program. In this paper, we examined the influence of dysgraphia on kinematic characteristics of normal and dysgraphic Italian children from 2nd to 5th grade of primary school. Three cursive tasks (sequence of lelele and Accurate and Fast copy of a sentence) were proposed and several kinematic parameters were evaluated. Since differences were present among grades both in normal and dysgraphic children, each parameter was compared between children coming from corresponding grades by means of the Wilcoxon rank sum test. The main results showed significant differences between the two groups within each grade for curvilinear velocity, total length and number of letters per second. Pen-lift durations were significantly different only in the Accurate and Fast tasks while number of strokes per second as well as stroke duration and length showed significant differences depending on the task and grade. These differences support the hypothesis of a lower fluency and automation as well as a different motor planning in dysgraphic subjects. Finally, many kinematic parameters could be useful for an early identification of dysgraphia in order to activate an immediate rehabilitative treatment.