Summary: DYNAMICS OF GECKOS RUNNING VERTICALLY.
K. Autumn*, S.T. Hsieh, D.M. Dudek, J. Chen, C.
Chitaphan, and R.J. Full. Univ. of California, Berkeley.
Geckos with adhesive toe pads rapidly climb even smooth
vertical surfaces. We challenged geckos (Hemidactylus
garnoti) to climb up a smooth vertical track that contained a
3D force platform. Kinematics from 3 cameras operating at
5001000fields/s showed that geckos climbed vertically at
up to 77cm/s with a stride frequency of 15Hz. Geckos used
a trotting gait in the majority of trials. During each step,
whole body vertical (in the direction of motion), lateral and
horizontal force all decreased to zero when the animal
attached or detached its toe pads. Peak vertical force was
twice body weight at mid-stance. Legged animals running on
a level attain a constant average velocity by accelerating and
decelerating their center of mass (COM) with each step.
Geckos climbed at a constant average velocity without
generating decelerating forces on their COM in the direction
of motion. Changes in vertical kinetic energy comprised