Effects of egg-bar shoes on the 3-dimensional kinematics of the distal forelimb in horses walking on a sand track.

This research explores the effect of egg-bar shoes on the movement of horses’ forelimbs, specifically on the motion of the three digital joints. The study noted significant changes in movement when these shoes are used as compared to standard shoes, which could validate the clinical use of egg-bar shoes in horses.

Objective and Methodology

• The objective of the research was to understand better the effects of egg-bar shoes on the three-dimensional (3D) kinematics of the horse’s distal forelimb. This was done by observing horses walking on a sand track.
• The researchers conducted this study on four healthy horses. They surgically attached ultrasonic markers to the four distal segments of the left forelimb of each horse. They then recorded the 3D movements of these segments while the horses were walking on a sand track.
• The digital joints’ rotations were calculated using a joint coordinate system, and the data obtained from horses shod with egg-bar shoes were compared to horses with standard shoes.

Results

• The study found that egg-bar shoes reduced the initial sinking of the heels into the ground during landing. The heels were raised by up to 5.1 degrees compared to standard shoes at mid-stance.
• Simultaneously, there was an increase in maximal flexion of the distal and proximal interphalangeal joints at the beginning of the stance phase.
• At heel-off, extension of the distal interphalangeal joint was reduced by 3.8 degrees.
• In extrasagittal planes of movement, egg-bar shoes prevented the medial quarter from sinking into the ground, leading to a slight reduction in distal interphalangeal joint’s medial rotation and lateromotion (sideways movement).

Conclusions

• Egg-bar shoes prevent the heels and, to a lesser degree, the medial side of the hoof from sinking into the ground while walking on a sand track. They also contribute to a decrease in the distal interphalangeal joint’s maximal extension at heel-off and stabilize the hoof in the transversal plane.
• The quantitative results from this research support the use of egg-bar shoes clinically. These shoes seem to change the biomechanics of a horse’s gait in a way that might be beneficial, especially on softer surfaces such as sand.