High-speed gallop locomotion in the Thoroughbred racehorse. II. The effect of incline on centre of mass movement and mechanical energy fluctuation.

The research investigates how incline impacts the mechanical energy changes and mechanical cost of transportation when horses gallop up slopes of varying degrees. It was found that most of the work is carried out during the hindlimb stance and increased effort is needed to move uphill, which corresponds to a rise in the horse’s potential energy.

Methods and Techniques

• The experiment involved six racehorses galloping at speeds between 9.0 to 12.0 m/s across different gradients.
• An inertial sensor was attached to the horses’ thoracic vertebrae to capture trunk movements in six degrees of freedom. This sensor provided information on linear movements (back and forth, side to side, up and down) and rotational movements (roll, pitch and heading).
• Footfall timings were recorded through a tried and tested system of accelerometers strapped to the horses’ limbs.
• The horses’ speed was tracked using a GPS data logger.
• Details regarding the track’s inclines were procured via a track survey.
• Calculations of displacement, velocity, and acceleration were made based on the collected kinematic data.
• Total mechanical energy fluctuations and mechanical cost of transport were estimated from these measurements.

Findings

• The results depicted that incline had a minor effect on the horse’s trunk movement while galloping.
• The need for increased work to maneuver the horse uphill was demonstrated by the rise in linear mechanical work and MCT. This work led to increased potential energy of the horse’s center of mass (CoM).
• The majority of the work within a stride was performed during the stance of the hindlimbs.

Significance

• This research offers novel insights into the mechanics of uphill locomotion in galloping horses. Understanding these dynamics improves our knowledge on how animals move on various terrains, which can impact fields like veterinary medicine and animal sports training.