Effects of Head-Neck Position and Ground Surface on Gait Kinematics in Ridden Brazilian Criollo Horses.

Objective Overview

• This study examined how the position of the head and neck and the type of ground surface affect the walking and trotting movement patterns of ridden Brazilian Criollo horses.
• It aimed to identify unique biomechanical features in these horses, particularly focusing on diagonal limb coordination and support patterns during gait.

Introduction and Purpose

• The Criollo horse is known for its exceptional endurance and is traditionally used in various working roles that demand stability and efficiency.
• Despite its importance, detailed biomechanical studies on the Criollo breed’s locomotion are limited.
• This research focused on two main factors that might influence gait:
  • Head and neck position (HNP), which affects balance and movement coordination.
  • The type of ground surface (soft vs. hard), which impacts limb support during walking or trotting.
• The objective was to understand how these factors influence diagonal dissociation — a characteristic of trotting horses describing whether the hind or forelimb contacts the ground first in a diagonal pair — and limb support patterns.

Methods

• The study was conducted on eleven clinically sound Criollo horses.
• High-speed video recording at 120 frames per second was used to capture the horses’ gait kinematics while ridden.
• Two different head and neck positions (HNP1 and HNP2) were analyzed:
  • HNP1 favored more hindlimb-first diagonal contact (positive dissociation).
  • HNP2 showed more forelimb-first diagonal contact (negative dissociation).
• Horses were assessed on two types of surfaces:
  • Soft ground, which was associated with more hindlimb-first dissociation and tripedal support phases.
  • Hard ground, which mainly showed synchronous or non-dissociated diagonal limb contacts.
• Kinematic data was correlated with forelimb and pelvic morphometric measurements to examine possible anatomical influences on gait patterns.

Findings

• Diagonal dissociation was observed in 85.24% of hoof contacts, indicating that a standard symmetrical trot with perfectly simultaneous diagonal contacts was uncommon.
• Differences in HNP influenced the type of diagonal dissociation:
  • HNP1 (head/neck in one position) had more positive diagonal dissociations (hindlimb contacts first).
  • HNP2 had more negative dissociations (forelimb contacts first), with the difference statistically significant (p = 0.0398).
• Soft ground generally promoted hindlimb-first diagonal dissociation across both HNPs (p = 0.0446) and was linked to increased occurrence of tripedal limb support, meaning three limbs were in contact with the ground during parts of the gait cycle.
• On hard ground, horses favored synchronous diagonal contacts and fewer tripedal support phases.
• Correlations between limb support patterns and morphometric features were present but weak to moderate (correlation coefficients R ≤ 0.40):
  • Thoracic monopedal and tripedal supports had weak correlations with forelimb dimensions.
  • Pelvic monopedal and tripedal supports showed weak to moderate correlations with global body size dimensions.

Interpretation and Conclusion

• The observed high prevalence of dissociated limb contacts suggests that the Criollo horse does not typically perform a perfectly symmetrical trot.
• The variations related to head and neck position and surface type imply that gait adaptations help the horse maintain functional efficiency and stability, especially in conditions relevant to its traditional use (endurance and working activities on varied terrains).
• The weak to moderate anatomical correlations suggest that while body measurements have some influence on gait and limb support patterns, other factors such as neuromuscular control, training, and functional adaptation likely play important roles.
• Overall, the findings reveal a distinct biomechanical gait signature for the Brazilian Criollo horse, reflecting evolutionary and functional adaptations.

Significance

• This study provides valuable biomechanical insights into a breed important for endurance and working tasks.
• Understanding how head-neck position and surface affect gait can support better training, riding, and welfare practices tailored specifically for Criollo horses.
• It also contributes to the broader knowledge of equine locomotion, particularly regarding how different breeds may exhibit unique gait patterns linked to their morphology and typical uses.