Background: Children with developmental disorders who require occupational therapy often show clumsiness in handwriting (hereafter referred to as clumsy children). The quality of handwriting has been reported to be deteriorated in children who had physical function-related issues for using handwriting tools. However, to date there has not been any clinical research to investigate the types and severity of deficits in physical function that influence the using handwriting tools. Similarly, how the trends and the severity of problems in physical function affect the characteristics of the results of handwriting task was previously unaddressed. Objective: This study investigated the influence of characteristics of physical function on drawing performance and drawing motion in clumsy children.

Method: Participants were healthy children and clumsy children enrolled in grades 2-6 of elementary school. The participants' drawing performance was evaluated using the triangle drawing task on a tablet personal computer. The participants' drawing motion was evaluated using the two-dimensional movement analysis device. The physical function of clumsy children was evaluated using the clinical observational assessment. Results: The largest stray distance, the range of speed and the difference of speed for the healthy child group by grade and each clumsy child. The sway length ratio of the clumsy children differed from those of the healthy children group. Clumsy children who exhibited poor drawing skills also had problems in posture maintenance, muscle condition, upper limb coordination, and eye movement.

Conclusion: We found the influence of poor physical function on poor drawing and drawing motion in clumsy children.