Pitch then power: limitations to acceleration in quadrupeds

Area of Science:

• Biomechanics
• Animal Physiology
• Sports Science

Background:

• Rapid acceleration and deceleration are crucial for survival in predator-prey dynamics and athletic performance.
• These abilities are subject to strong natural and artificial selection pressures.
• Understanding the constraints on acceleration is vital for both evolutionary and performance contexts.

Purpose of the Study:

• To investigate the mechanical and physiological limitations governing maximal acceleration and deceleration.
• To examine these constraints in elite athletes bred and trained for speed.

Main Methods:

• Studied maximal acceleration in racing greyhounds.
• Studied maximal acceleration and deceleration in polo ponies.
• Observed these performances in a competitive setting.

Main Results:

• Maximum acceleration and deceleration are governed by two primary limits: one mechanical and one physiological.
• At lower speeds, acceleration/deceleration is limited by geometric constraints preventing pitching (nose-up or tail-up).
• At higher speeds, the primary limitation shifts to muscle power.

Conclusions:

• Geometric and muscle power constraints effectively define the upper limits of acceleration and deceleration.
• These findings have implications for understanding evolutionary adaptations and optimizing athletic training.