Effects of occupational therapy on improvements in the handwriting ability of the adult non-dominant hand: An exploratory randomised controlled trial.

Introduction: Occupational therapy often involves handwriting acquisition practices that include the non-dominant hand when improvements in the dominant hand function are not possible because of trauma or stroke. This study explored whether character tracing and using a pegboard can effectively improve the handwriting of the non-dominant hand.

Methods: A randomised controlled trial involving 60 healthy university students aged ≥18 years was conducted. Participants were randomly assigned to the writing group, peg group or control group. The character recognition rate was evaluated by computer software. Furthermore, character quality and writing speed were evaluated by humans using global legibility scales. Evaluations were performed before the intervention (baseline) and on days 5 and 10 of the intervention. Using the non-dominant hand, the writing group traced characters on paper with a ballpoint pen, and the peg group used a pegboard for 15 min/day for 10 days.

Results: Compared with the peg and control groups, the writing group showed significant improvements in the character recognition rate and global legibility scale score. However, the global legibility scale score did not improve to the same level as that achieved with the dominant hand. None of the evaluation scores of the peg group showed significant improvements compared with those of the control group. There were no significant differences in improvements in the writing speed of the writing and peg groups compared with the control group.

Conclusion: Tracing characters can improve the handwriting ability of the non-dominant hand, but using a pegboard may be less effective. Future research is needed to examine how much practice is necessary to improve the handwriting ability of the non-dominant hand sufficiently.