Assessment of the reliability of a technique to measure postural sway in horses.

The research study examines the reliability of using a force platform, which measures center-of-pressure (COP) values, as a method to study postural sway or the balance in horses. The study concludes that this method produced reliable results and could be useful for assessing balance issues in horses.

Methods

• The study involved six 2-year-old horses that were free from any lameness and neurological diseases.
• The horses were made to stand still with all four hooves on a force platform.
• COP data were recorded at a frequency of 1,000 Hz and 3-dimensional kinematics were collected at 60 Hz for a duration of 10 seconds.
• Five trials were conducted at each of the three time periods (15-minute intervals) or at one time period on three different days.
• Mean values for each set of five trials and actual, normalized, and relative COP variables were calculated.
• The reliability of the method was assessed through the use of an agreement boundary which provides limits to ascertain the margin of error and variability in measurements.

Results

• The results of the COP measurements within the same day and across different days were found to be similar, and yielded small agreement boundary limits.
• The reliability of the measurement varied for different variables such as area, mediolateral range, radius, craniocaudal range, and velocity. The smallest relative reliability was found for the area, followed by the mediolateral range, radius, craniocaudal range, and velocity.
• Head height had the highest relative intraday reliability (12%), but a high agreement boundary limit drop at the same time (+/- 0.15 m).

Conclusion

• The study concludes that the method of using a force platform for analyzing postural sway in horses produced reliable results.
• This technique could provide a simple and sensitive measure for identifying balance problems in horses.
• The agreement boundaries that were recorded provide 95% confidence intervals, which could be used as limits of error and variability in measurements. If these boundaries are exceeded in real-world applications, it can indicate meaningful effects such as balance issues in the horse.