Stevens Nancy Jeanne
Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA.
J Exp Zool A Comp Exp Biol. 2006 Nov 1;305(11):953-63. doi: 10.1002/jez.a.336.
The coordination of limb movements during mammalian locomotion has been well documented in the literature. Most mammals use lateral sequence (LS) gaits, in which a forelimb follows an ipsilateral hind limb during the stride cycle. Primates, however, tend to utilize diagonal sequence (DS) gaits, whereby a contralateral forelimb follows a given hind limb during the stride cycle. A number of scenarios have been offered to explain why primates favor DS gaits, most of them relating to the use of the arboreal habitat and, in particular, the exploitation of a terminal branch niche. Yet to date, there is surprisingly little evidence to support the advantage of DS gaits for negotiating different aspects of the terminal branch environment. Nonetheless, it is apparent that primates possess unique morphologies and a higher than typically recognized degree of flexibility in gait sequence pattern, both of which likely offer advantages for moving upon discontinuous and unstable terminal branches. This paper reviews potential explanations for the use of DS gaits in primates and considers mechanisms by which gait sequence may be altered during different types of arboreal challenges.
哺乳动物运动过程中肢体动作的协调性在文献中已有详尽记载。大多数哺乳动物采用侧序（LS）步态，即在一个步幅周期内，前肢跟随同侧后肢运动。然而，灵长类动物倾向于采用对角序（DS）步态，即在步幅周期内，对侧前肢跟随特定的后肢运动。人们提出了多种设想来解释灵长类动物为何偏好DS步态，其中大多数与树栖栖息地的利用有关，特别是对末梢树枝生态位的开发利用。然而，迄今为止，令人惊讶的是几乎没有证据支持DS步态在应对末梢树枝环境不同方面时具有优势。尽管如此，很明显灵长类动物具有独特的形态结构以及比通常认为的更高的步态序列模式灵活性，这两者可能都为在间断且不稳定的末梢树枝上移动提供了优势。本文回顾了对灵长类动物使用DS步态的潜在解释，并探讨了在不同类型的树栖挑战中步态序列可能发生改变的机制。
