Locomotor characteristics of horses with navicular disease.

This research investigates the gait of horses suffering from navicular disease by measuring their ground reaction forces. The study shows these horses have abnormal force patterns regardless of sensory loss in the palmar region of their foot, suggesting an underlying abnormal gait could make certain horses more susceptible to the disease.

Methods

• The study involved 17 clinically normal Thoroughbreds and 8 Thoroughbred horses diagnosed with navicular disease.
• A force plate was used to measure the ground reaction forces as the horses trotted. This data was collected to understand the force-time curve variables which represent the force exerted by a horse in various phases of its stride.
• The force-time curve variables were derived from four points at the beginning and at the end of the vertical and craniocaudal (head-to-tail) horizontal force plots.
• The researchers conducted a principal component analysis separately on the data collected at the beginning and end of each stride. This statistical method was used to highlight the main patterns in the data.
• Similar measurements and analysis were taken before and after the horses with navicular disease were subjected to a nerve block, which disrupted sensation to the palmar digital region of the hoof.

Results

• Before the nerve block was administered, horses with navicular disease showed significant difference in their ground reaction force variables compared to normal horses, both at the beginning and end of the stance phase of the stride.
• After the nerve block was administered, the horses with navicular disease still showed significant difference in ground reaction force variables, but only at the beginning of the stance phase.

Conclusions

• The study concluded that horses suffering from navicular disease exhibit abnormal force patterns throughout their stride, which are not eliminated by sensory deprivation in the palmar region of the foot.
• The presence of abnormal patterns in a horse without navicular disease suggests some horses might be inherently predisposed to develop the condition due to an abnormal gait pattern.
• The researchers suggest that analysis of horse gait patterns could assist in early detection and the implementation of tailored management strategies for horses susceptible to navicular disease.