Relationship between morphological and stabilographic variables in standing horses.

Area of Science:

• Equine Biomechanics
• Animal Physiology
• Postural Control

Background:

• Stabilograms analyze center of pressure (COP) movement in the horizontal plane to assess postural balance.
• Existing stabilographic variables quantify balance, but their dependence on animal size is not well understood.
• Understanding size-dependency is crucial for accurate interpretation of postural performance in horses.

Purpose of the Study:

• To identify the most representative morphological variable for horse size.
• To determine the most representative stabilographic variables for postural balance.
• To evaluate if size normalization enhances the estimation of postural performance in horses.

Main Methods:

• Measured morphological variables (croup height, mass, base of support length/width) in 24 horses.
• Recorded stabilographic variables (craniocaudal, mediolateral, resultant amplitudes, velocities, frequencies) using force plates.
• Employed principal component analysis to identify key morphological and stabilographic components.

Main Results:

• Body mass was identified as the primary morphological variable representing horse size.
• Five stabilographic variables (CC amplitude, CC velocity, CC frequency, ML amplitude, ML frequency) explained 91% of sway pattern variation.
• Horse mass correlated with CC velocity and ML frequency; larger horses showed slower ML sway frequencies and smaller CC velocities.

Conclusions:

• Postural balance measurements in horses are influenced by body size.
• Body mass is a significant factor affecting stabilographic variables like CC velocity and ML frequency.
• Size normalization may be necessary for accurate comparative analysis of postural performance across horses of different sizes.