Differences in Muscle Activity Patterns and Graphical Product Quality in Children With Graphomotor Impairment

Drawing on a vertical surface, such as a blackboard (rather than a horizontal surface) is often used by occupational therapists as a way of developing fine motor control and visual motor integration in children. While there is anecdotal evidence to support this intervention, preliminary results in healthy children showed no differences in graphical quality while drawing on vertical or horizontal surfaces. This however was not investigated in children with graphomotor impairments.

The goal of this study is to determine whether movements produced on a vertical surface differ in their performance level and muscle activation patterns compared to movements produced on a horizontal surface.

The investigators predict that the level of performance on the vertical surface will exceed the level of performance on the horizontal surface. Additionally, the investigators hypothesize that the proximal muscles will be more activated and fatigued (in longer tasks) while drawing on the vertical surface, while the distal muscle will be more activated and fatigued while drawing on the horizontal surface.

Study group Inclusion criteria:

• Up to 50 percentile in the long form Beery-Buktenica Developmental Test of Visual-Motor Integration (Beery VMI).

Exclusion criteria

• children in special education,
• any orthopedic or neurologic impairment,
• visual impairment that could not be corrected with glasses, or
• ability to understand and follow simple instructions, reported by the parents.