Writing kinematics and graphic rules in children with ADHD

Abstract

Introduction/Objective. The aim of this study was to coIntroduction/Objective. The aim of this study was to compare kinematic features and graphic rules of writing between children with attention deficit/hyperactivity disorder (ADHD) (with and without medical treatment) and typically developed children (TDC). Methods. In total, 55 children (26 with ADHD/ten subjects were on methylphenidate treatment and 29 TDC) completed a writing task on a digitizing board (in three repetitions; using non-inking stylus) which included a semicircle tracing, triangle, and letter copying. Kinematic features of movements in all tasks and graphic rules during a semicircle tracing were analyzed. Graphic rules were observed as expected movements (selecting the starting point and direction of tracing). Results. The values of kinematic parameter jerk were significantly larger in TDC group compared to all ADHD subjects (regardless of treatment) and increased constantly with semicircle task progression and repetition in both groups. Children with ADHD without methylphenidate treatment used overall slower movements compared to TDC. The tracing of children with ADHD taking methylphenidate was more automated (with less change in movement velocity and acceleration) compared to TDC. In ADHD group only, those with treatment traced faster and more automated compared to those without treatment. The majority of subjects used expected movements in semicircle tracing and this percentage increased with the task repetition (without difference between ADHD and TDC). Conclusion. Both children with ADHD and TDC used similar approach in the tracing task and were compliant with graphic rules. Methylphenidate treatment may positively influence writing kinematics in children with ADHD. Task repetition also influences writing.