Grip strength and pen pressure are not key contributors to handwriting difficulties in children with developmental coordination disorder

Introduction
Children with developmental coordination disorder have significant difficulties with handwriting. Factors such as hand grip strength and pen pressure are often assumed by clinicians to play a role, although empirical evidence is lacking. The aim of this study was to measure grip strength and pen pressure to examine their relationships with handwriting performance in children with developmental coordination disorder.

Method
Sixteen 8–14-year-old children with developmental coordination disorder were compared with 20 typically developing age- and gender-matched controls. Palmar, pinch and tripod grip strength were measured using hand dynamometers. The mean pressure exerted on a writing tablet by the pen was obtained during a handwriting task. Group comparisons were made and correlations conducted between grip strength and pen pressure and a range of handwriting product and process measures.

Results
There were no group differences on the three measures of grip strength. However, the developmental coordination disorder group exerted less pressure on the writing surface compared to typically developing peers. There were no significant correlations between grip strength or pen pressure and handwriting performance in children with developmental coordination disorder.

Conclusion
Clinicians should be cautious when using measures of grip strength or pen pressure to inform them about aspects of handwriting skill in children with developmental coordination disorder.