Noy Lior, Hassin-Baer Sharon, Fay-Karmon Tsvia, Kattouf Noora, Israeli-Korn Simon, van der Wel Robrecht, Friedman Jason
Faculty of Business Administration, Ono Academic College, Kiryat Ono, Israel.
Movement Disorders Institute, Department of Neurology, Chaim Sheba Medical Center, Ramat Gan, Israel.
J Neuroeng Rehabil. 2025 Mar 6;22(1):51. doi: 10.1186/s12984-025-01592-1.
In general, people are unable to produce slow, smooth movements - as movements become slower (i.e., with longer durations), they become jerkier. A hallmark feature of Parkinson's disease is bradykinesia - slowness of movement. In this study, we investigate the intersection of these two observations - how do people with Parkinson's disease (PwP) perform in a slow tracking task, and how does it vary as a function of movement frequency? On the one hand, as PwP move more slowly in day-to-day life, they may be better in a slow tracking task. On the other hand, their general impairment in movement production may lead to worse tracking outcomes.
We used a well-tested tracking task known as the one-person mirror game, where participants control the left-right movement of an ellipse on a graphics tablet. They did so using a stylus and were instructed to match the horizontal location of a stimulus, an ellipse moving in a sinusoidal fashion at different movement frequencies and peak velocities. We calculated the submovement rate, identifying both type 2 (acceleration zero crossings) and type 3 (jerk zero crossings) from the trajectories, as well as relative position error (dX) and mean timing error (dT). To account for age-related performance decline, we tested three groups: PwP (N = 31), age-matched controls (OC; N = 29), and younger controls (YC; N = 30) in a cross-sectional study, and used mixed-design ANOVAs to compare across groups and movement frequencies.
We reproduced earlier results showing that slow movements (i.e., with lower frequencies) require more submovements to track. PwP also generally performed more submovements than the other two groups, but only for type 3 submovements, whereas OC and YC performed submovements at a similar rate. Younger controls (YC) performed fewer tracking errors than older participants (both PwP and OC), and OC performed better than PwP.
The ability to smoothly track showed an age-related decline, with PwP producing more errors and using more submovements. This may be due to reduced automaticity in movement production. The findings of the study can be used to guide optimal movement frequencies for motor training for older adults and PwP.
一般来说，人们无法做出缓慢、流畅的动作——随着动作变得更慢（即持续时间更长），动作会变得更不平稳。帕金森病的一个标志性特征是运动迟缓——动作缓慢。在本研究中，我们探究这两种现象的交叉点——帕金森病患者（PwP）在慢速跟踪任务中的表现如何，以及它如何随运动频率而变化。一方面，由于帕金森病患者在日常生活中动作更慢，他们在慢速跟踪任务中可能表现更好。另一方面，他们在动作产生方面的总体损伤可能导致更差的跟踪结果。
我们使用了一种经过充分测试的跟踪任务，即单人镜像游戏，参与者在数位板上控制一个椭圆的左右移动。他们使用触控笔进行操作，并被要求匹配一个刺激物的水平位置，该刺激物是一个以不同运动频率和峰值速度做正弦运动的椭圆。我们计算了子运动速率，从轨迹中识别出2型（加速度过零点）和3型（加加速度过零点），以及相对位置误差（dX）和平均时间误差（dT）。为了考虑与年龄相关的表现下降，我们在一项横断面研究中测试了三组：帕金森病患者（N = 31）、年龄匹配的对照组（OC；N = 29）和年轻对照组（YC；N = 30），并使用混合设计方差分析来比较不同组和运动频率之间的差异。
我们重现了早期的结果，即缓慢动作（即频率较低）需要更多子运动来跟踪。帕金森病患者通常也比其他两组进行更多的子运动，但仅针对3型子运动，而OC组和YC组的子运动速率相似。年轻对照组（YC）比年长参与者（帕金森病患者组和OC组）的跟踪误差更少，且OC组比帕金森病患者组表现更好。
平稳跟踪的能力显示出与年龄相关的下降，帕金森病患者产生更多误差并使用更多子运动。这可能是由于动作产生的自动化程度降低。该研究结果可用于指导老年人和帕金森病患者运动训练的最佳运动频率。
