Department of Bioengineering, George Mason University, Fairfax, VA, United States of America.
PeerJ. 2024 Sep 3;12:e17858. doi: 10.7717/peerj.17858. eCollection 2024.
The human upper extremity is characterized by inherent motor abundance, allowing a diverse array of tasks with agility and adaptability. Upper extremity functional limitations are a common sequela to Stroke, resulting in pronounced motor and sensory impairments in the contralesional arm. While many therapeutic interventions focus on rehabilitating the weaker arm, it is increasingly evident that it is necessary to consider bimanual coordination and motor control.
Participants were recruited to two groups differing in age (Group 1 ( = 10): 23.4 ± 2.9 years, Group 2 ( = 10): 55.9 ± 10.6 years) for an exploratory study on the use of accelerometry to quantify bilateral coordination. Three tasks featuring coordinated reaching were selected to investigate the acceleration of the upper arm, forearm, and hand during activities of daily living (ADLs). Subjects were equipped with acceleration and inclination sensors on each upper arm, each forearm, and each hand. Data was segmented in MATLAB to assess inter-limb and intra-limb coordination. Inter-limb coordination was indicated through dissimilarity indices and temporal locations of congruous movement between upper arm, forearm, or hand segments of the right and left limbs. Intra-limb coordination was likewise assessed between upper arm-forearm, upper arm-hand, and forearm-hand segment pairs of the dominant limb.
Acceleration data revealed task-specific movement features during the three distinct tasks. Groups demonstrated diminished similarity as task complexity increased. Groups differed significantly in the hand segments during the buttoning task, with Group 1 showing no coordination in the hand segments during buttoning, and strong coordination in reaching each button with the upper arm and forearm guiding extension. Group 2's dissimilarity scores and percentages of similarity indicated longer periods of inter-limb coordination, particularly towards movement completion. Group 1's dissimilarity scores and percentages of similarity indicated longer periods of intra-limb coordination, particularly in the coordination of the upper arm and forearm segments.
The Expanding Procrustes methodology can be applied to compute objective coordination scores using accessible and highly accurate wearable acceleration sensors. The findings of task duration, angular velocity, and peak roll angle are supported by previous studies finding older individuals to present with slower movements, reduced movement stability, and a reduction of laterality between the limbs. The theory of a shift towards ambidexterity with age is supported by the finding of greater inter-limb coordination in the group of subjects above the age of thirty-five. The group below the age of thirty was found to demonstrate longer periods of intra-limb coordination, with upper arm and forearm coordination emerging as a possible explanation for the demonstrated greater stability.
人类上肢具有内在的运动丰富性，能够灵活适应各种任务。上肢功能受限是中风的常见后遗症，导致对侧手臂明显的运动和感觉障碍。虽然许多治疗干预措施都集中在康复较弱的手臂上，但越来越明显的是，有必要考虑双手协调和运动控制。
为了进行一项关于使用加速度计来量化双手协调的探索性研究，我们招募了两组年龄不同的参与者（第 1 组（n=10）：23.4±2.9 岁，第 2 组（n=10）：55.9±10.6 岁）。选择了三个协调的上肢伸展任务，以研究日常生活活动（ADL）中上肢、前臂和手部的加速度。受试者在每个上臂、前臂和每个手上都配备了加速度和倾斜传感器。数据在 MATLAB 中进行了分段，以评估肢体间和肢体内的协调。肢体间协调通过上、下臂、前臂或手部节段之间相似性指数和运动时间来表示。对优势肢体的上臂-前臂、上臂-手部和前臂-手部节段对之间的肢体内协调进行了类似的评估。
加速度数据揭示了三个不同任务中特定于任务的运动特征。随着任务复杂性的增加，组间的相似性降低。在扣纽扣任务中，两组的手部节段差异显著，第 1 组在扣纽扣时手部节段没有协调，而上臂和前臂引导伸展以达到每个纽扣的协调能力较强。第 2 组的不相似性得分和相似性百分比表明，上肢和前臂的协调时间较长，特别是在运动完成阶段。第 1 组的不相似性得分和相似性百分比表明，上肢和前臂节段的协调时间较长，特别是在协调时。
可以使用可访问且高度准确的可穿戴加速度传感器，应用扩展 Procrustes 方法计算客观的协调得分。任务持续时间、角速度和峰值滚动角度的发现得到了先前研究的支持，这些研究发现老年人的动作较慢，运动稳定性降低，四肢之间的偏侧性降低。年龄增长导致向双手灵巧性转变的理论得到了支持，即 35 岁以上组的肢体间协调程度更高。年龄在 35 岁以下的组被发现具有更长的肢体内协调时间，而上臂和前臂的协调可能是表现出更高稳定性的原因。
