The anatomy and biomechanics of acceleration performance in the hare and greyhound

In an unpredictable environment, animals must not only strive to achieve fast and/ or efficient locomotion, but must also be able to rapidly change speed and direction, and negotiate uneven and varied terrain. The requirement of rapid acceleration is particularly important to enable effective chase of prey or escape from predation. This thesis investigates the anatomy and biomechanics of acceleration performance. The muscle-tendon architecture and geometry (muscle moment arms) of both pelvic and thoracic limbs of the hare and greyhound was determined. Both species were shown to possess significant adaptations for sprint and acceleration performance, including substantial volumes of pelvic limb (particularly hip extensor) muscle. Whilst the pelvic limb also possessed tendons capable of elastic energy storage and return, the thoracic limbs of both species were more generalised, with the presence of high force muscles - able to stabilise and prevent collapse of the limb during locomotion. Racing greyhounds showed exceptional acceleration performance and achieved very highú mechanical power outputs. Accelerating greyhounds and hares were shown to alter their running mechanics with acceleration. In the greyhound, work and power delivered at the hock joint increased significantly with acceleration. Hind limb effective mechanical advantage decreased with higher accelerations. Accelerating hares showed a decrease in the ratio of fore: hind limb vertical impulses with acceleration. Three hypotheses were investigated in order to propose what limits maximum acceleration in quadrupeds. Limited grip, limited power, and simple inherant anatomical dimensions were considered, concluding that under specific circumstances, all have the potential to constrain maximum accelerative ability.EThOS - Electronic Theses Online ServiceGBUnited Kingdo