Maki B E, Whitelaw R S, McIlroy W E
Centre for Studies in Aging, Sunnybrook Health Science Centre, University of Toronto, Ont., Canada.
Neurosci Lett. 1993 Jan 4;149(1):87-90. doi: 10.1016/0304-3940(93)90354-n.
The bilateral symmetry of feet-in-place responses to postural perturbations in the anterior-posterior direction has not been well studied. This paper presents evidence that right- and left-leg responses that appear to be approximately symmetrical in the sagittal plane may actually involve an asymmetry in the frontal plane, namely, a lateral weight shift. Comparison with trials where subjects stepped suggests that these lateral weight shifts represent early preparations for stepping responses that are aborted before the foot is actually lifted. Thus, it would seem that compensatory stepping involves a sequence of discrete modifiable stages, rather than a single immutable motor program. Moreover, postural responses that appear to be similar in the sagittal plane may actually be seen to involve quite different postural strategies, i.e. in terms of preparation for stepping, when viewed in the frontal plane.
对于前后方向姿势扰动的原地足部反应的双侧对称性尚未得到充分研究。本文提供的证据表明，在矢状面看似大致对称的右腿和左腿反应，在额状面可能实际上存在不对称，即侧向体重转移。与受试者迈步试验的比较表明，这些侧向体重转移代表了在脚实际抬起之前就被中止的迈步反应的早期准备。因此，似乎补偿性迈步涉及一系列离散的可修改阶段，而不是单一不变的运动程序。此外，在矢状面看似相似的姿势反应，当在额状面观察时，实际上可能涉及相当不同的姿势策略，即在迈步准备方面。
