Grip and limb force limits to turning performance in competition horses

Area of Science:

• Biomechanics
• Animal Locomotion

Background:

• Manoeuverability is crucial for terrestrial locomotion and predator-prey dynamics.
• Bend running necessitates additional leg force for centripetal acceleration, unlike straight-line running.
• Human sprinters reduce speed on bends, a phenomenon predictable by limb force limitation models.

Purpose of the Study:

• To investigate the turning performance limits in horses during high-speed locomotion.
• To compare horse turning dynamics with predictions from biomechanical models of running.

Main Methods:

• Collected horizontal speed and angular velocity data of horses during polo and horse racing.
• Analyzed turning performance across various scenarios and turn radii.

Main Results:

• Horses exhibited reduced horizontal speed on large-radius turns, aligning with limb force limitation models.
• On small-radius turns, horses decreased angular velocity with increasing speed, consistent with friction-limited centripetal force.

Conclusions:

• Horse turning performance is constrained by different factors depending on the turn radius.
• Limb force limits speed on wider turns, while hoof-surface friction limits tighter turns to prevent slipping.