Department of Biology, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA.
J Exp Biol. 2012 Jan 15;215(Pt 2):247-55. doi: 10.1242/jeb.061135.
Bipedal running is common among lizard species, but although the kinematics and performance of this gait have been well characterized, the advantages in biologically relevant situations are still unclear. Obstacle negotiation is a task that is ecologically relevant to many animals while moving at high speeds, such as during bipedal running, yet little is known about how obstacles impact locomotion and performance. We examined the effects of obstacle negotiation on the kinematics and performance of lizards during bipedal locomotion. We quantified three-dimensional kinematics from high-speed video (500 Hz) of six-lined racerunners (Aspidoscelis sexlineata) running on a 3 m racetrack both with and without an obstacle spanning the width of the track. The lizards did not alter their kinematics prior to contacting the obstacle. Although contact with the obstacle caused changes to the hindlimb kinematics, mean forward speed did not differ between treatments. The deviation of the vertical position of the body center of mass did not differ between treatments, suggesting that in the absence of a cost to overall performance, lizards forgo maintaining normal kinematics while negotiating obstacles in favor of a steady body center of mass height to avoid destabilizing locomotion.
两足奔跑在蜥蜴物种中很常见，但尽管这种步态的运动学和性能已经得到很好的描述，但在生物学上相关的情况下的优势仍不清楚。在高速移动时，如在两足奔跑中，障碍物的协商是许多动物在生态上相关的任务，但我们对障碍物如何影响运动和性能知之甚少。我们研究了障碍物协商对蜥蜴在两足运动中运动学和性能的影响。我们从六线快跑者（Aspidoscelis sexlineata）在 3 米赛道上以 500 Hz 的高速视频量化了三维运动学，赛道上有和没有障碍物。蜥蜴在接触障碍物之前不会改变它们的运动学。虽然与障碍物接触会导致后肢运动学发生变化，但在处理之间，平均前进速度没有差异。身体质心的垂直位置偏差在处理之间没有差异，这表明在不影响整体性能的情况下，蜥蜴在障碍物协商中放弃保持正常运动学，以稳定身体质心高度，避免运动不稳定。
