title: The kangaroo's tail propels and powers pentapedal locomotion.
abstract: When moving slowly, kangaroos plant their tail on the ground in sequence with their front and hind legs. To determine the tail's role in this 'pentapedal' gait, we measured the forces the tail exerts on the ground and calculated the mechanical power it generates. We found that the tail is responsible for as much propulsive force as the front and hind legs combined. It also generates almost exclusively positive mechanical power, performing as much mass-specific mechanical work as does a human leg during walking at the same speed. Kangaroos use their muscular tail to support, propel and power their pentapedal gait just like a leg.
authors.affiliation: Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
authors.forename: Shawn M
authors.initials: SM
authors.lastname: O'Connor
authors.affiliation: School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Terence J
authors.initials: TJ
authors.lastname: Dawson
authors.affiliation: Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA.
authors.forename: Rodger
authors.initials: R
authors.lastname: Kram
authors.affiliation: Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada mdonelan@sfu.ca.
authors.forename: J Maxwell
authors.initials: JM
authors.lastname: Donelan
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005121:Extremities / Q000502:physiology; D005260:Female; D005684:Gait; D008124:Locomotion / Q000502:physiology*; D007614:Macropodidae / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D013623:Tail / Q000502:physiology*
keywords: biomechanics; energetics; kangaroo; locomotion; pentapedal