The kinematics of loading and fatigue in the standardbred trotter.

This research examined how the process of pulling a significant load impacts the locomotion patterns of Standardbred trotter horses during racing. It found that both loading and fatigue from this load significantly alter these locomotion patterns, potentially influencing certain types of injury to the horse’s movement system.

Research Methodology

• The study was conducted on four mature healthy Standardbred horses.
• The horses were made to trot with and without a horizontal-pulling load of 34 kg.
• The trotting was continued until the horses no longer willingly kept pace with the treadmill, even when encouraged.
• The researchers used a bipolar electrocardiogram to monitor the heart rate of the horses every minute.
• To analyze the movements, the kinematics for five consecutive strides of the horses were captured on film.
• The exercise on the treadmill lasted for around 7 to 10 minutes.

Results and Observations

• The average heart rate of the horses was found to be 206 beats/minute at the conclusion of the exercise.
• Due to the exertion of pulling the load, the horses notably reduced the stance phase time for both their forelimbs and hindlimbs.
• Three out of the four horses decreased their stride lengths as a result of the increased loading.
• The general movement pattern of the horses stayed relatively similar despite the additional load.
• More noticeable changes in the movement pattern were observed due to fatigue.
• It was observed that the limbs of the horse experienced significant compression due to greater joint excursion during the stance phase as a result of fatigue.
• The stride length of the horses increased significantly due to fatigue.

Conclusion

The findings of this research clearly show that both loading and fatigue significantly change the locomotor patterns of the Standardbred trotter. Although the horses could maintain similar joint movements with increased stride frequency under a significant horizontal load, power capacity compromise due to fatigue made it challenging for them to retain stride frequency. The increase in joint excursion from fatigue could significantly influence certain types of injuries to the horse’s locomotor system. This study provides valuable insights for training and injury prevention in racehorses.