Influence of the force applied and its period of application on the outcome of the flexion test of the distal forelimb of the horse.

The research article discusses how the levels of force applied, and its duration of application, impacts the results of a flexion test on a horse’s lower forelimb. By adjusting these variables, the researchers found that they could manipulate the outcome of the test, potentially raising questions around the standardization of these procedures.

Objective

The aim of the study was to explore the impact of the force applied and its period of application on the outcome of the distal forelimb flexion test in horses. The researchers wanted to understand how changes in these two factors might affect the resulting classification of horses as either ‘sound’ or ‘lame’.

Methodology

• The study was conducted on a group of eight sound horses.
• The flexion test results were scored based on a standard clinical classification, as well as by measuring the angle of maximum fetlock extension via the MacReflex gait analysis system.
• The researchers adjusted both the force of application and the period during which the force was applied, to observe the effects on the results of the flexion test.

Results

• The researchers found a strong correlation (r = 0.96) between the clinical score and kinematic parameter measured by the MacReflex system.
• Both the force applied and the period of application impacted the outcome of the flexion test.
• Increasing both variables led to more horses being classified as lame, while reducing them resulted in all horses being classified as sound.
• A five-minute flexion test at either full or 75% force resulted in the majority of the horses being classified as lame.

Conclusion

The research concluded that the manner in which the flexion test is conducted may need greater standardization to account for variance in the level of force and duration of its application. This standardization could lead to more consistent and useful results, improving the effectiveness of the flexion test for diagnosing lameness in horses.