Variation in surface strain on the equine hoof wall at the midstep with shoeing, gait, substrate, direction of travel, and hoof shape.

The research study examines the deformation and strain experienced by a healthy horse’s front hoof during movement, and how these change with different conditions and hoof shapes.

Methods and Objectives

• The primary goal of this study was to examine and record the strain experienced by a healthy horse’s front hoof during movement under varying conditions and hoof shapes.
• Strain was recorded from the outer surface of the right forehooves of 12 horses, using 5 rosette gauges placed around the hoof’s circumference.
• The focus was on observing the changes in both the magnitudes and orientations of strain when different factors were altered.

Factors Tested

• Shoeing vs. Unshod: Comparing whether being shoed or unshoed significantly changed the hoof’s mechanical behavior.
• Gait (Walk vs. Trot): Exploring if there are differences in hoof deformation between these two common horse gaits.
• Substrate (Treadmill vs. Ground): Comparing the differences in strain patterns on different surfaces.
• Turning Direction (Straight, Left, Right): Looking into whether the direction of travel affected the hoof strain.
• Hoof Shape Parameters (Toe Length, Toe Angle, Medial and Lateral Wall Angles): Understanding how hoof shape could influence strain and hoof deformation.

Results and Observations

• Shoeing led to some strain reorientation but did not essentially change the magnitudes of the larger, compressive principal strain. Shoes decreased the variation in strains, indicating they help stabilize the hoof’s deformation.
• Strain magnitudes were significantly greater when trotting than walking, but the orientation change was minimal, implying a similar deformation pattern between these two gaits.
• There were small yet significant differences between locomotion on the treadmill and on the ground. These differences were more noticeable at the toe of the hoof than at the sides.
• While turning, the inside quarter of the hoof experienced 40% more strain than straight-line movement. Strain was similarly reduced on the opposite quarter.
• Strain magnitudes increased with toe length and toe angle but were inversely proportional to the medial and lateral angles. This suggests that a hoof with more erect quarters is stiffer and possibly offers less impact absorption.
• The changes related to toe length and angle correlated with the animals’ body size range and contradicted results from in vitro tests.