Does graphomotor intervention influence handwriting variability?

Abstract

ABSTRACT Handwriting is a complex task that results from a sequence of movements of different members. It has a specific variability’s structure, i.e., a fractal dynamics and temporal organization, which inform about the regularity with which children write as well as their adaptability to the task. The purpose of this study was to investigate: 1) variability’s structure after a graphomotor intervention; 2) variability’s structure 6 months after the intervention. 41 children (8-9 years) performed a 5-minute copy on a digitizing table, in three moments: before and after intervention and 6 months later. Movements were recorded using an x-y digitizing tablet with an inking pen and MovAlyzeR®. Nonlinear dynamic parameter sample entropy (SamEn) was used to assess pattern of regularity of sample kinematic time series, and the correlation dimension (CoDim) to characterize the fractal dynamics of handwriting. Intervention program was developed during 16 sessions (30’), twice a week, in small groups. We found significant differences in the horizontal component of SamEn and CoDim in the intergroup analysis from the pre to the follow-up moment. In both variables the trend is increasing with the control group assuming higher values. Children with the intervention became less regular in the horizontal component, but with a different level of control, that is, with greater adaptability. It is concluded that the children became aware of the strategies learned but only after the intervention did, they apply them in a visible way, with repercussions on the copying task. Nonlinear methods are an important tool to quantify changes in graphomotor behavior.