All our work on leg yielding focused on flexion, but to do proper corners, shoulder fores, and lead changes, you have to have a proper bend.
What is the difference between bend and flexion? Bend refers to the arc of the horse's entire body, while flexion is just focused on the horse's neck and jaw. A horse can be straight through the body, but flexed through the neck such as during a leg yield and still be correct and balanced. A horse that is flexed left, however, but bend right in the body, is crooked.
Different horses have different degrees of bendability. A longer necked horse will usually have more ability to flex its neck laterally, and a longer backed horse will usually have more ability to arc its body. Unless injured though, all horses will be more bendable in front of the withers (neck and jaw) than behind the withers (rib cage and pelvis). A proper bend will have the horse bent fluidly from ears to tail, which means the rider often has to limit the arc in the neck, to the amount the body can be flexed.
Most of you will notice your horse flexes and bends more easily one way that the other. This is because, just like people, more horses have a dominant side. Again, just like people, the typical horse is right side dominant. A right sided horse will typically favour their left lead (because they push off from their right hind when cantering to the left), but will prefer trotting to the right, and will bend better to the right. Why? Because the right side is stronger, and so tighter, and the horse will want to bring that right hind up and under more to its midline, which will tighten that right side.
Humans and horses are thought to have dominant sides to increase reaction times: when you have one side clearly favoured by the brain, your reaction will be to use that side without a second though...if both sides were equal there may be a moment of indecision while deciding which hand/leg to move with first, resulting in precious loss of time.
You will hear me refer to "soft side" and "stiff side". As per above, the horse will typically be soft (more bendable) to the right, and stiffer to the left...even though it is actually kind of reversed.
This of it this way:
Think of the muscles on the left being like a soft stretched out spring: not very strong and so easy to stretch. The muscles on the right are like a tightly coiled and strong spring. For the horse, this would mean that they are always wanting to be tipped a little to the right to feel even muscle wise. Similarly for the rider to feel they have even tension/contact on both sides of the mouth, they will want to have a shorter rein on the right side, which will just perpetuate the issue.
For the horse this will feel normal and straight as this is how they would carry themselves when left to their own devices, the problem is that for arena work, in particular dressage and jumping, we need the horse to be more even on both sides, so that they jump evenly, corner equally well, and can change leads both ways fluidly.
It is up to the rider to help the horse stretch out that tight/strong right side, and be more bendable to the left. How to do this, will be covered in Part 2 and beyond!
Karen