Effect of Water Depth on Limb and Back Kinematics in Horses Walking on a Water Treadmill.

The study focuses on understanding the impact of walking in different depths of water on the limb and back movements of horses, as water treadmills are commonly used in their training and rehabilitation process.

Research Objectives

The researchers aimed to identify how different water depths influence the movement or kinematics of horse limbs and backs while maintaining a consistent walking speed. Such understanding is crucial for designing effective and efficient water treadmill (WT) exercise sessions for horses’ training and rehabilitation.

Research Methodology

• Six horses with an average age of 15 years were included in the study, each undergoing a standardized WT exercise session lasting 19 minutes at a consistent walking speed of 1.6 m/s. The depths of water used were 0.0 cm, 7.5 cm, 21.0 cm, 32.0 cm, and 47.0 cm respectively.
• The horses were fitted with ten waterproof light-emitting-diode tea-light-markers and reflective-spheres at specific locations and inertial measurement units on the poll/withers/left and right tubera coxae and sacrum. These devices helped in assessing the range of motion (ROM) alterations at the mentioned locations.
• Univariable mixed effects linear regression analyses were performed for the collected data to understand the impact of water depth on limb and back kinematics, with statistical significance set at P ≤ .05.

Research Findings

• As the water depth increased, carpal and tarsal flexion during swing increased in a clear and consistent non-linear manner (P < 0.0001).
• There was observable growth in thoracic spine flexion-extension ROM with increased water depth (P < 0.0001).
• The dorsoventral and mediolateral ROM of the sacrum and left and right tubera coxae increased as water depth elevated (P < 0.001).
• It was noted that horses adapted to increments in water depth until reaching a threshold point, after which the biomechanical response stabilized while pelvic roll increased.

Conclusion

The researchers concluded that even moderate changes in water depth, while maintaining a walking speed of 1.6 m/s, can bring about significant alterations in the limb and back movements of horses. The findings bring attention to the crucial aspects to be considered while designing and implementing WT exercise programs for horses.