Abourachid Anick, Herbin Marc, Hackert Rémi, Maes Ludovic, Martin Véronique
FRE2696, CNRS, MNHN, Université P6, Col. de France, Muséum National d'Histoire Naturelle, Département Ecologie et Gestion de la Biodiversité, FRE 2696, Pavillon d'Anatomie Comparée, CP 55, 57 rue Cuvier, 75231 Paris cedex 05, France.
J Exp Biol. 2007 Jan;210(Pt 2):366-72. doi: 10.1242/jeb.02632.
A framework to study interlimb coordination, which allowed the analysis of all the symmetrical and asymmetrical gaits, was recently proposed. It suggests that gait depends on a common basic pattern controlling the coordination of the forelimbs (fore lag, FL), the coordination of the hindlimbs (hind lag, HL) and the relationship between these two pairs of limbs (pair lag, PL) in an anteroposterior sequence of movement (APS). These three time parameters are sufficient for identifying all steady gaits. We assumed in this work that this same framework could also be used to study non-steady locomotion, particularly the transitions between symmetrical and asymmetrical gaits. Moreover, as the limbs are coordinated in time and also in space during locomotion, we associated three analogous space parameters (fore gap, FG; hind gap, HG and pair gap, PG) to the three time parameters. We studied the interlimb coordination of dogs and cats moving on a runway with a symmetrical gait. In the middle of the runway, the gait was disturbed by an obstacle, and the animal had to change to an asymmetrical coordination to get over it. The time (FL, HL, PL) and space (FG, HG, PG) parameters of each sequence of the trials were calculated. The results demonstrated that the APS method allows quantification of the interlimb coordination during the symmetrical and asymmetrical phases and during the transition between them, in both dogs and cats. The space and time parameters make it possible to link the timing and the spacing of the footfalls, and to quantify the spatiotemporal dimension of gaits in different mammals. The slight differences observed between dogs and cats could reflect their morphological differences. The APS method could thus be used to understand the implication of morphology in interlimb coordination. All these results are consistent with current knowledge in biomechanics and neurobiology, therefore the APS reflects the actual biological functioning of quadrupedal interlimb coordination.
最近提出了一个用于研究肢体间协调的框架，该框架允许对所有对称和不对称步态进行分析。它表明，步态取决于一个共同的基本模式，该模式以前后运动序列（APS）控制前肢的协调（前滞后，FL）、后肢的协调（后滞后，HL）以及这两对肢体之间的关系（对滞后，PL）。这三个时间参数足以识别所有稳定步态。在这项工作中，我们假设这个相同的框架也可用于研究非稳定运动，特别是对称和不对称步态之间的转换。此外，由于肢体在运动过程中在时间和空间上都是协调的，我们将三个类似的空间参数（前间隙，FG；后间隙，HG和对间隙，PG）与三个时间参数相关联。我们研究了在跑道上以对称步态移动的狗和猫的肢体间协调。在跑道中间，步态受到障碍物干扰，动物必须改变为不对称协调才能越过它。计算了试验每个序列的时间（FL、HL、PL）和空间（FG、HG、PG）参数。结果表明，APS方法可以量化狗和猫在对称和不对称阶段以及它们之间转换过程中的肢体间协调。空间和时间参数使得可以将脚步的时间和间距联系起来，并量化不同哺乳动物步态的时空维度。在狗和猫之间观察到的细微差异可能反映了它们的形态差异。因此，APS方法可用于理解形态学在肢体间协调中的作用。所有这些结果都与生物力学和神经生物学的现有知识一致，因此APS反映了四足动物肢体间协调的实际生物学功能。
