Movement strategies in vertical aiming of older adults
Movement strategies in vertical aiming of older adults
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DOI：
10.1007/s00221-011-2947-x
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发表时间：
2012-02-01
影响因子：
2
通讯作者：
Rodacki, Andre
中科院分区：
文献类型：
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作者：
Bennett, Simon J.;Elliott, Digby;Rodacki, Andre
当前的研究检查了老年人瞄准垂直目标时的运动动力学。中年晚期和老年早期的参与者完成了 20 次针对位于肩高起始位置向下或向上 0.16 m 的小目标的试验。瞄准方向有显着影响，导致更多的次运动，这主要反映了与向上目标相比，向下瞄准时的下射。在包含子运动的试验中，当瞄准向下的目标时，两组都表现出较短的总运动时间，同时主要运动的持续时间减少和子运动幅度增加。分散的测量也根据次运动的幅度而不同，因此当瞄准向下方向时，主要运动存在更大的空间和时间变化。虽然证据有限，表明各组之间存在差异，但在实现向下目标时，年龄和几项相关指标之间存在显着相关性。值得注意的是，在包含子运动的试验中，老年参与者表现出较大的幅度和较长的子运动持续时间，以及较短的主要运动幅度。当向下瞄准时，峰值速度的空间变异性也会随着年龄的变化而增加，但在没有子运动的试验中则不会。由于试验类型之间缺乏一致的发现，与运动产生的物理限制相关的解释被打折扣。相反，我们建议年长的参与者在瞄准垂直目标时在运动运动学上表现出策略差异，并且这些差异随着年龄的增长而逐渐变化，以保持速度与准确性的关系。
The current study examined the movement kinematics of older adults when aiming to vertically oriented targets. Late middle-age and early old-age participants completed 20 trials to a small target located downward or upward by 0.16 m from a home position at shoulder height. Aiming direction had a significant effect, resulting in more submovements, which were mostly reflective of undershooting when aiming to the downward compared to upward target. In trials containing a submovement, both groups exhibited shorter total movement time, concomitant with a decrease in duration of the primary movement and an increase in submovement amplitude, when aiming to the downward target. Measures of dispersion also differed in accord with the amplitude of submovements, such that there was greater spatial and temporal variability in the primary movement when aiming in the downward direction. While there was limited evidence of a difference between the groups, there were significant correlations between age and several dependent measures when aiming to the downward target. Of note, in trials containing submovements, older participants exhibited larger amplitude and longer duration submovements, as well as shorter amplitude primary movement. Spatial variability at peak velocity also increased as a function of age when aiming downward, but not in trials without submovements. An explanation related to physical limits on movement production is discounted given the lack of consistent findings between trial types. Instead, we suggest older participants' exhibit strategic differences in movement kinematics when aiming to vertically located targets, and that these change progressively with age in order to maintain speed-accuracy relations.