Tsai Yi-Ju, Lin Sang-I
Department of Physical Therapy, College of Medicine, National Cheng Kung University, No. 1 Ta-Hsueh Road, Tainan, 701, Taiwan.
Age (Dordr). 2015 Feb;37(1):9739. doi: 10.1007/s11357-014-9739-8. Epub 2015 Jan 22.
Forward reaching is an integral part of many essential daily activities. It is often performed while standing quietly or after standing up from a seated position. This study sought to determine how a preceding balance task and aging would affect the task performance and movement strategy. Twenty-two healthy young and 20 older adults participated in this study and performed forward reaching under two task conditions. In forward reach (FR), reaching was performed during quiet standing. In up-and-reach (UR), subjects stood up from a seated position and then reached forward. A motion analysis system was used to calculate the location of the center of mass (COM) and joint angles at the initial and final positions, and the finger, COM, and joint angular displacements during the reaching task. For both groups, UR was initiated in a more flexed posture and had a significantly shorter reach distance and greater ankle dorsiflexion angle, compared to FR. The location of the COM, however, did not differ between the two task conditions. Older adults were found to significantly slow down their downward and forward COM motions in UR but not young adults. These findings showed that a preceding balance task increased the task demand and required modifications in the movement strategy. For older adults, the impact of increased task demand was greater, and adopting a cautious strategy could help to complete the task safely.
向前伸展是许多基本日常活动不可或缺的一部分。它通常在安静站立时或从坐姿起身之后进行。本研究旨在确定先前的平衡任务和衰老如何影响任务表现及运动策略。22名健康的年轻人和20名老年人参与了本研究，并在两种任务条件下进行向前伸展。在向前伸展（FR）任务中，伸展是在安静站立时进行。在起身伸展（UR）任务中，受试者从坐姿起身，然后向前伸展。使用运动分析系统来计算质心（COM）的位置以及初始和最终位置的关节角度，以及伸展任务期间手指、质心和关节的角位移。与FR相比，两组在UR任务开始时姿势都更弯曲，伸展距离明显更短，踝关节背屈角度更大。然而，两种任务条件下质心的位置并无差异。研究发现，老年人在UR任务中向下和向前的质心运动明显减慢，而年轻人则不然。这些发现表明，先前的平衡任务增加了任务需求，并需要对运动策略进行调整。对于老年人来说，任务需求增加的影响更大，采取谨慎的策略有助于安全地完成任务。
