Meeting Abstract

91.6  Friday, Jan. 7  Galloping cheetahs: the challenges of high speed locomotion HUDSON, P.E.*; CORR, S.A.; WILSON, A.M.; Royal Veterinary College, London; University of Nottingham; Royal Veterinary College, London phudson@rvc.ac.uk

Running at high speed presents quadrupeds with several challenges, not only with straight line speed but also when accelerating, decelerating and manoeuvring. There is much speculation in the literature as to what limits speed with limits of force, power and minimum swing times commonly mentioned. As the fastest living land mammal with a recorded speed of 28.6 ms^-1, we are investigating the galloping gait of the cheetah to see how it may be adapted to such challenges and limitations. Here we compare the kinematics and kinetics of galloping in the cheetah to the racing greyhound, an animal of a similar mass and morphology yet can only achieve a maximum speed of around 19 ms^-1.
We have collected data from nine cheetahs and six greyhounds to date. Each animal chased a mechanical lure along a 90 m runway in which eight Kistler force plates were embedded. Subjects were videoed from both sides using four AOS high speed cameras (1280 x 600, 1000fps).
To date our runs have been recorded at disappointingly submaximal speeds (cheetah 17 ms^-1, greyhound 13 ms^-1), however, several differences in their gaits can still be observed. At these speeds the cheetahs used significantly longer forelimb stance times; however, their contact angles did not exhibit any species difference. Considerable movements of the scapular have previously been observed and we are currently investigating if this may explain our results. There is also much speculation as to how the flexion and extension of the back may aid high speed locomotion. Both the cheetah and greyhound have considerable spinal movement when galloping; however, the movements exhibited are very different. We have been examining the movements of their CoM during a galloping stride to investigate this further.