Effect of Peripheral Sensory Electrical Stimulation Combined With Handwriting Practice on Nondominant Handwriting...

Introduction Tracing letters is recognized in occupational therapy as an effective method for improving writing skills with the non-dominant hand. Additionally, peripheral sensory nerve electrical stimulation (PES) increases corticospinal tract excitability and enhances the acquisition and retention of motor skills. This study aimed to investigate whether combining character tracing with PES can improve non-dominant handwriting ability in adults. Methods The participants were randomly assigned to one of three groups: handwriting with PES (PES group), handwriting only (non-PES group), and a control group. All participants were instructed to copy a sample character using a ballpoint pen with their non-dominant hand at baseline and five days after the intervention. The primary outcome was character quality assessed using computer-based character recognition software and human-rated global legibility scales. Writing speed during the copying task was the secondary outcome. The intervention groups practiced character tracing for 15 minutes per day for five consecutive days. In the PES group, stimulation was applied for 40 minutes before and 15 minutes during each handwriting session. Outcome data were tested for normality, and non-normally distributed data were log-transformed before analysis. Analysis of covariance (ANCOVA) was used to adjust for the writing speed. Results ANCOVA revealed a significant improvement in character quality in the PES group compared with that in the control group after the intervention. However, no significant differences were observed between the PES and non-PES groups or between the non-PES and control groups. Conclusion When adjusted for writing speed, handwriting practice combined with PES significantly improved non-dominant handwriting quality compared with no intervention. However, PES alone did not demonstrate a clear additional benefit over handwriting practice.