早期手臂运动中面向玩具的变化：手部运动学

Toy-oriented changes during early arm movements: hand kinematics.

作者信息

Bhat A N, Galloway J C

机构信息

Infant Motor Behavior Laboratory, Department of Physical Therapy, Biomechanics and Movement Science Program, University of Delaware, Newark, DE 19716, USA.

出版信息

Infant Behav Dev. 2006 Jul;29(3):358-72. doi: 10.1016/j.infbeh.2006.01.005. Epub 2006 Mar 7.

DOI:10.1016/j.infbeh.2006.01.005

PMID:17138291

Abstract

UNLABELLED

In a recent cross-sectional study, we found that young infants changed their spontaneous arm movements in the presence of a toy, termed 'toy-oriented changes', in systematic ways beginning many weeks before their first consistent reaches [Bhat, A. N., Heathcock, J. H., & Galloway, J. C. (2005). Toy-oriented changes in hand and joint kinematics during the emergence of purposeful reaching. Infant Behavior and Development, 28(4), 445-465]. The purpose of the present study was to test specific hypotheses regarding toy-oriented changes in a longitudinal design.

METHODS

Thirteen infants were observed every other week from 8 weeks of age up to the onset of reaching. At each session, hand and joint motions were observed with and without a toy present using a high-speed motion capture system. This paper focuses on the toy-oriented changes in hand variables.

RESULTS

As predicted, infants displayed a meaningful pattern of toy-oriented changes, which systematically changed as infants approached the first week of reaching. During the Early phase (8-10 weeks before reaching), infants scaled down their movement length and speed in the presence of a toy. During the Mid phase (4-6 weeks before reaching), infants scaled up movement number and speed, increased movement smoothness, and decreased their hand-toy distance in the presence of a toy. During the Late phase (within 2 weeks of reaching), infants continued to change their hand's position to get closer to the toy and began contacting it. Interestingly, movement number and smoothness displayed similar developmental patterns, where movement length and speed displayed similar patterns.

CONCLUSION

Toy-oriented adaptation of arm movements emerges in the first months of life and forms a complex, yet tractable continuum with purposeful reaching. These results provide a foundation to test more specific hypotheses of hand and joint coordination in both typically developing infants and those infants born at risk for coordination impairments.

摘要

未标注

在最近的一项横断面研究中，我们发现，在首次持续伸手够物的数周前，年幼婴儿就开始以系统的方式改变其在玩具出现时的自发手臂动作，即所谓的“以玩具为导向的变化”[Bhat, A. N., Heathcock, J. H., & Galloway, J. C. (2005). 有目的伸手够物出现过程中手部和关节运动学的以玩具为导向的变化。《婴儿行为与发展》，28(4)，445 - 465]。本研究的目的是在纵向设计中检验关于以玩具为导向的变化的具体假设。

方法

从13名婴儿8周龄开始，每隔一周观察一次，直至伸手够物开始。在每次观察期间，使用高速动作捕捉系统在有玩具和无玩具的情况下观察手部和关节运动。本文重点关注以玩具为导向的手部变量变化。

结果

正如预期的那样，婴儿表现出一种有意义的以玩具为导向的变化模式，随着婴儿接近首次伸手够物的第一周，这种模式会系统性地改变。在早期阶段（伸手够物前8 - 10周），婴儿在有玩具的情况下会减小其动作长度和速度。在中期阶段（伸手够物前4 - 6周），婴儿会增加动作次数和速度，提高动作流畅性，并在有玩具的情况下减小手部与玩具的距离。在后期阶段（伸手够物前2周内），婴儿继续改变手部位置以靠近玩具并开始接触它。有趣的是，动作次数和流畅性呈现出相似的发展模式，而动作长度和速度也呈现出相似的模式。