Bradykinesia and delayed step initiation are central features of Parkinson's disease (PD) and have been linked to reduced movement vigor. Evidence suggests that externally imposed urgency may upregulate vigor and improve motor speed. Previous home-based cueing interventions without time limits improved gait but failed to reduce reaction times, indicating that time constraints may be critical. We conducted a randomized controlled trial to evaluate whether time-constrained, visually guided reaching and stepping exercises enhance response speed in PD. Sixty participants with idiopathic PD (Hoehn & Yahr I-III) completed 24 supervised, home-based sessions using a set of small interactive devices that provided visual and auditory cues and recorded response times. The experimental group trained with time windows adapted during each session to maintain ∼80% success, receiving immediate success/failure feedback, while the control group performed identical tasks without time restrictions. Response times were assessed before and after training with choice stepping and reaching reaction time tasks in a laboratory setting, alongside gait and mobility tests. Repeated measures ANOVA revealed significant group × time interactions favoring the experimental group for both reaching (p < 0.05) and stepping (p < 0.001) reaction times, with medium-to-large effect sizes, whereas controls showed no change. Gait speed improved in both groups, with no additional between-group differences. These findings demonstrate that introducing temporal urgency during reactive training produces meaningful improvements in bradykinesia-related response times in individuals with PD, supporting the integration of time-constrained cueing into scalable home-based rehabilitation. ClinicalTrials.gov: NCT05829915.
Keywords: balance; exercise; gait disorders; occupational therapy; physiotherapy; rehabilitation.
Beating the Clock Improves Bradykinesia in Parkinson's Disease.People with Parkinson's disease often move slowly and have trouble starting actions such as reaching for an object or taking the first step. One reason may be that the brain does not create enough urgency to move quickly. Setting short time limits can create this urgency and encourage faster movement. In this study, we tested a home-based exercise program using small devices that gave light and sound signals. When a light appeared, participants had to touch it with their hand or step toward it. Everyone trained several times a week. The key difference was that in one group the time allowed to touch the target was shortened during training so that people succeeded about 80% of the time. The other group did the same exercises without time pressure. We found that participants who trained with time limits became faster at both reaching with the hand and starting a step. Those who trained without time limits did not improve movement speed. These results show that adding short, achievable time limits to simple exercises can help people with Parkinson's disease move faster. This approach is practical, safe, and can be done at home, making it a promising tool for rehabilitation and everyday life.