Eilam D, Shefer G
Canadian Center for Ecological Zoology, Department of Zoology, Tel-Aviv University, Ramat-Aviv, Israel.
J Exp Biol. 1992 Dec;173:155-63. doi: 10.1242/jeb.173.1.155.
Conventional descriptions of interleg coupling relate to anatomical definitions such as fore- or hindlegs, right or left legs (i.e. the body is the frame of reference). This convention is obvious for forward walking, where forelegs (in anatomical terms) are also the leading legs (in terms of direction). In backward locomotion, however, the leading legs in terms of direction are the hindlegs in terms of anatomy. What effects do the anatomy and direction of movement have on the sequence of stepping? Our observations on the locomotion of mole rats in a transparent acrylic tunnel revealed that, as in nature, mole rats moved both forwards and backwards. They typically employed a diagonal sequence of steps in forward walking, whereas in backward walking they typically employed a lateral sequence. However, when stepping was described with movement direction as the frame of reference, both forward and backward walking were made up of the same sequence of steps. The same invariant trend was recorded during backward galloping, but to a lesser extent than during walking. We suggest that the backward sequence is simply a reversal of the forward sequence: a hindleg during backward locomotion acts like a foreleg in forward locomotion, while a foreleg acts like a hindleg in forward locomotion. Interleg coupling therefore remains invariant in relation to the direction of locomotion.
传统上对腿间耦合的描述涉及解剖学定义，如前腿或后腿、右腿或左腿（即身体作为参考框架）。这种惯例在向前行走时很明显，从解剖学角度看的前腿（在解剖学术语中）也是从方向角度看的领先腿（在方向方面）。然而，在向后运动时，从方向角度看的领先腿在解剖学上却是后腿。解剖结构和运动方向对迈步顺序有什么影响呢？我们对透明丙烯酸隧道中鼹形鼠运动的观察表明，和在自然环境中一样，鼹形鼠既能向前也能向后移动。它们在向前行走时通常采用对角迈步顺序，而在向后行走时通常采用侧向迈步顺序。然而，当以运动方向作为参考框架来描述迈步时，向前和向后行走都由相同的迈步顺序组成。在向后飞奔时也记录到了相同的不变趋势，但程度比行走时小。我们认为，向后顺序只是向前顺序的颠倒：向后运动时的后腿在向前运动中起前腿的作用，而向前运动时的前腿在向前运动中起后腿的作用。因此，腿间耦合相对于运动方向保持不变。
