Even if they can’t tell you where it hurts, horses with back pain will soon be able to benefit from Scottish and Austrian research focusing on the long muscles of the equine back.

In the article, which is slated for an upcoming edition of The Veterinary Journal, researchers reported that electromyography (EMG) readings on the longissimus dorsi muscles of 15 healthy horses walking on treadmills were used to pinpoint painful areas that might otherwise have gone undetected.

Researchers now have a standard for comparison when mapping EMG activity on horses with suspected back pain.

Electromyography patterns help researchers to precisely track muscle activity within a step cycle. In healthy horses, maximum activity occurs at vertebra T16 (“T” standing for thoracic vertebra), an area located under the middle of a standard saddle’s caudal (rear) padding, according to Theresia Licka, PhD, DVM, senior lecturer in equine surgery at the Royal (Dick) School of Veterinary Studies in Scotland and member of the Movement Science Group in Vienna, where the research was performed.


Horse on treadmill with sensors to measure movement of back muscles
COURTESY DR. THERESIA LICKA

Measuring the movement of a horse’s back muscles.


“The area of the highest muscle activity is also the area of highest pressures measured under the saddle,” Licka said. “Ill-fitting saddles can be a problem, (but) even the best riders on the best fitting saddles will contribute to a (pre-existing) problem if the muscle is hard.”

The EMG readings also provide information about the use of the equine back muscles in different gaits. Whereas at the trot the muscles