SPOTTING FRONTLIMB LAMENESS
The indicator of lameness that is easiest to see is the head bob. In sound horses, the head will move up and down slightly twice during each trot stride. It is up during the swing phase and down during the stance phase of each front limb. In a sound horse the motion of the head and neck will be symmetric for both sides.
A “head bob” is often seen when this motion is asymmetric between the two front limbs and exaggerated downward on the sound leg. This is typically associated with front-limb lameness. Most people with moderate horse experience can detect a bob, but that only tells you that a something is wrong. You have to understand why and how the bob is happening to utilize it as an indictor of which limb is the problem.
Essentially, when a horse is bobbing his head, he lifts it just before the painful leg lands. He uses the considerable weight of his head and neck to shift his weight and to keep it off the sore limb as much as he can. The down motion on the sound leg is exaggerated because this limb is accepting greater weight bearing. We use the phrase “down on sound” to remember this relationship, but sometimes the “up” is the only thing you’ll see.
A sound horse jogging on a longe line will