Effect of forelimb lameness on hoof kinematics of horses at a walk.

This research investigates the impact of unilateral, weight-bearing lameness in horses on hoof movement during a walk. After inducing lameness in the right forelimb of clinically normal horses, the study tracked changes in hoof kinematics. It further assessed whether the incurred changes return to baseline values after the administration of perineural anesthesia.

Methods

• The study involved 6 clinically normal Quarter Horses. A sole-pressure model was used to induce three grades of lameness in the right forelimb of each horse.
• After the induction of lameness, perineural anesthesia was given to eliminate lameness.
• Optical kinematics were obtained for both forelimbs when the horse was walking, before (baseline values) and after the induction of lameness, and after the administration of perineural anesthesia.
• Linear acceleration profiles were used to identify hoof events. Each stride was divided into five segments: hoof-contact, break-over, initial-swing, terminal-swing, and total-swing.
• Kinematic variables were then compared within and between limbs for each segment using a repeated-measures ANOVA statistical model.

Results

• For the hoof-contact and terminal-swing segments, the hoof of the left (nonlame) forelimb had greater sagittal-plane orientation than did the hoof of the right (lame) forelimb.
• The break-over duration and maximum cranial acceleration were increased from baseline for the lame limb after the induction of lameness.
• After perineural anesthesia, break-over duration for the lame limb returned to a baseline-like value, and the orientation of the hoof during the terminal-swing segment did not differ between the lame and nonlame limbs.

Conclusions

• Subclinical (not visibly perceptible) unilateral lameness in the forelimb of a horse significantly alters hoof kinematics when the horse is walking.
• The application of hoof kinematics can aid in detecting such subclinical lameness in horses.