Centre of mass movement and mechanical energy fluctuation during gallop locomotion in the Thoroughbred racehorse

• DOI: 10.1242/jeb.02439
• Publication Date: 2006-09-19T19:31:45Z
• Authors: Thilo Pfau; Thomas H. Witte; Alan M. Wilson
• Keywords: Mechanical energy; Biomechanics; Elastic energy; Ground reaction force

During locomotion cyclical interchange between different forms of mechanical energy enhances economy; however, 100% efficiency cannot be achieved and ultimately some work must performed de novo. There is a metabolic cost associated with fluctuations in energy, even the most efficient animals. In this study we investigate exchanges involved high-speed gallop Thoroughbred race horses during over-ground using innovative, mobile data collection techniques. We use hoof-mounted accelerometers to capture foot contact times, GPS logger monitor speed an inertial sensor mounted over dorsal spinous processes fourth sixth thoracic vertebrae (the withers) horse trunk movement six degrees freedom. Trunk were used estimate centre mass (CoM). Linear (craniocaudal, mediolateral dorsoventral) rotational (roll, pitch heading) kinematic parameters (displacement, velocity acceleration) calculated for seven at speeds ranging from 7 17 m s(-1) their regular training sessions. These external (potential linear kinetic CoM) as well selected components internal (angular energy). Elastic storage limbs was estimated duty factor, sine wave assumptions published leg stiffness values. External changes dominated by craniocaudal velocity. Potential change, which phase front limb stances, small. small compared overall amplitude fluctuation energy. Galloping high does not therefore fit classical spring mechanics.