Analysis of kinematic parameters relationships in normal and dysgraphic children

Kinematic analysis of handwriting, using digital tablet together with appropriate tests and processing software, allows evaluation of subject graphomotor abilities. Several studies focused on the kinematic parameters extracted from the writing of both normal subjects and subjects with specific disorder, such as dysgraphia, recorded during simple tasks. However, relationships between these parameters have not yet been analyzed. The aim of this study was to examine and identify possible links between kinematic parameters like Amplitude (SA), Duration (SD) and Peak Velocity (PkVS) of Strokes extracted from handwriting and their changes between normal and dysgraphic children. Fifty normal and eighteen dysgraphic children, attending classes from 2nd to 5th grade of primary school, were involved in the study; three cursive tests were administered and analyzed. Results showed a linear relation between SA and PkVS parameters with a similar slope in both groups and reduced peak velocities in some dysgraphic children. A linear relationship was also present between SA and SD parameters in all tests for normal children while an unclear relation was found for dysgraphic children. The latter showed longer durations and slightly lower amplitudes than in normal subjects, in all tasks, as expected in case of poor fluency