Department of Kinesiology, University of Waterloo, Waterloo, Canada.
Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Canada.
PLoS One. 2018 Mar 12;13(3):e0193639. doi: 10.1371/journal.pone.0193639. eCollection 2018.
Kinematic analysis of upper limb reaching provides insight into the central nervous system control of movements. Until recently, kinematic examination of motor control has been limited to studies conducted in traditional research laboratories because motion capture equipment used for data collection is not easily portable and expensive. A recently developed markerless system, the Leap Motion Controller (LMC), is a portable and inexpensive tracking device that allows recording of 3D hand and finger position. The main goal of this study was to assess the concurrent reliability and validity of the LMC as compared to the Optotrak, a criterion-standard motion capture system, for measures of temporal accuracy and peak velocity during the performance of upper limb, visually-guided movements. In experiment 1, 14 participants executed aiming movements to visual targets presented on a computer monitor. Bland-Altman analysis was conducted to assess the validity and limits of agreement for measures of temporal accuracy (movement time, duration of deceleration interval), peak velocity, and spatial accuracy (endpoint accuracy). In addition, a one-sample t-test was used to test the hypothesis that the error difference between measures obtained from Optotrak and LMC is zero. In experiment 2, 15 participants performed a Fitts' type aiming task in order to assess whether the LMC is capable of assessing a well-known speed-accuracy trade-off relationship. Experiment 3 assessed the temporal coordination pattern during the performance of a sequence consisting of a reaching, grasping, and placement task in 15 participants. Results from the t-test showed that the error difference in temporal measures was significantly different from zero. Based on the results from the 3 experiments, the average temporal error in movement time was 40±44 ms, and the error in peak velocity was 0.024±0.103 m/s. The limits of agreement between the LMC and Optotrak for spatial accuracy measures ranged between 2-5 cm. Although the LMC system is a low-cost, highly portable system, which could facilitate collection of kinematic data outside of the traditional laboratory settings, the temporal and spatial errors may limit the use of the device in some settings.
上肢运动的运动学分析为中枢神经系统对运动的控制提供了深入的了解。直到最近，运动控制的运动学检查一直限于在传统研究实验室进行的研究，因为用于数据采集的运动捕捉设备不易携带且昂贵。最近开发的无标记系统 Leap Motion Controller (LMC) 是一种便携式且廉价的跟踪设备，可记录 3D 手和手指位置。本研究的主要目的是评估 LMC 与 Optotrak 的同时可靠性和有效性，Optotrak 是一种标准的运动捕捉系统，用于测量上肢视觉引导运动过程中的时间准确性和峰值速度。在实验 1 中，14 名参与者执行了指向计算机监视器上呈现的视觉目标的瞄准运动。 Bland-Altman 分析用于评估时间准确性（运动时间、减速间隔持续时间）、峰值速度和空间准确性（端点准确性）测量的有效性和一致性限制。此外，还使用单样本 t 检验来检验 Optotrak 和 LMC 获得的测量值之间的误差差是否为零的假设。在实验 2 中，15 名参与者进行了 Fitts 类型的瞄准任务，以评估 LMC 是否能够评估众所周知的速度-准确性权衡关系。实验 3 评估了 15 名参与者在执行由到达、抓取和放置任务组成的序列时的时间协调模式。t 检验的结果表明，时间测量的误差差与零显着不同。基于这 3 个实验的结果，运动时间的平均时间误差为 40±44ms，峰值速度的误差为 0.024±0.103m/s。LMC 和 Optotrak 之间空间准确性测量的一致性限制在 2-5cm 之间。尽管 LMC 系统是一种低成本、高度便携的系统，可促进传统实验室环境之外的运动学数据采集，但时间和空间误差可能会限制该设备在某些环境中的使用。
