RESUMO
BACKGROUND: Micrographia, or small handwriting, is a common symptom of Parkinson's disease (PD). Weighted pens have previously been recommended to improve handwriting, but there is limited research supporting their effectiveness. Additionally, previous research has demonstrated that music as an auditory cue can reduce variability in fine motor movements, but its effect on handwriting in people with PD remains unknown. PURPOSE: This study explored potential handwriting interventions for people with PD by evaluating the effectiveness of weighted pens and auditory cues on handwriting. STUDY DESIGN: This was a pilot cohort study. METHODS: Eight older adults with PD used a standard pen and a weighted pen to write continuous cursive "l"s on 1.5-cm-lined paper for a total of 10 seconds while listening to auditory cues in 4 conditions: control (silence), metronome, activating music, and relaxing music. Kinematic data were measured with sensors attached to the tip of each pen, and muscle activity was measured with electromyography sensors adhered to the extensor digitorum communis and first dorsal interosseous. RESULTS: When writing with the standard pen, peak-to-peak time was reduced in the metronome (control = 0.807 ± 0.121 seconds, metronome = 0.701 ± 0.100 seconds, p = 0.024) and activating (control = 0.807 ± 0.121 seconds, activating = 0.691 ± 0.113 seconds, p = 0.009) conditions compared to the control condition. Furthermore, the weighted pen increased the variability of distance between letter peaks (standard = 0.187 ± 0.010, weighted = 0.482 ± 0.065, p = 0.033) and the variability of time needed to complete each letter (standard = 0.176 ± 0.010, weighted = 0.187 ± 0.016, p = 0.042) compared to the standard pen. Finally, area under the curve of the extensor digitorum communis was reduced in the metronome (metronome = 66.03 ± 25.74 mV, control = 88.98 ± 30.40 mV, p = 0.034) and activating music (activating = 66.49 ± 26.02 mV, control = 88.98 ± 30.40 mV, p = 0.012) conditions compared to control when writing with the standard pen. CONCLUSIONS: These results suggest that weighted pens may not improve handwriting in novice users, but auditory cues appear beneficial. This can inform future directions in the research and clinical application of handwriting interventions for persons with PD.
