Full R J, Tu M S
Dept of Zoology, University of California, Berkeley, 94720
J Exp Biol. 1990 Jan;148:129-46. doi: 10.1242/jeb.148.1.129.
Six-legged pedestrians, cockroaches, use a running gait during locomotion. The gait was defined by measuring ground reaction forces and mechanical energy fluctuations of the center of mass in Blaberus discoidalis (Serville) as they travelled over a miniature force platform. These six-legged animals produce horizontal and vertical ground-reaction patterns of force similar to those found in two-, four- and eight-legged runners. Lateral forces were less than half the vertical force fluctuations. At speeds between 0.08 and 0.66 ms-1, horizontal kinetic and gravitational potential energy changes were in phase. This pattern of energy fluctuation characterizes the bouncing gaits used by other animals that run. Blaberus discoidalis attained a maximum sustainable stride frequency of 13 Hz at 0.35 ms-1, the same speed and frequency predicted for a mammal of the same mass. Despite differences in body form, the mass-specific energy used to move the center of mass a given distance (0.9 J kg-1m-1) was the same for cockroaches, ghost crabs, mammals, and birds. Similarities in force production, stride frequency and mechanical energy production during locomotion suggest that there may be common design constraints in terrestrial locomotion which scale with body mass and are relatively independent of body form, leg number and skeletal type.
六条腿的步行者——蟑螂，在移动时采用奔跑步态。通过测量红斑大蠊（Serville）在微型测力平台上移动时的地面反作用力和质心的机械能波动来定义这种步态。这些六条腿的动物产生的水平和垂直地面反作用力模式与在两条腿、四条腿和八条腿的奔跑者中发现的模式相似。侧向力小于垂直力波动的一半。在0.08至0.66米/秒的速度之间，水平动能和重力势能变化是同步的。这种能量波动模式是其他奔跑动物所采用的弹跳步态的特征。红斑大蠊在0.35米/秒时达到了13赫兹的最大可持续步频，这与相同质量的哺乳动物预测的速度和频率相同。尽管身体形态不同，但蟑螂、幽灵蟹、哺乳动物和鸟类用于将质心移动给定距离（0.9焦耳·千克⁻¹·米⁻¹）的单位质量能量是相同的。运动过程中力的产生、步频和机械能产生的相似性表明，陆地运动可能存在共同的设计限制，这些限制与体重成比例，并且相对独立于身体形态、腿的数量和骨骼类型。
