This does not necessarily mean he is a one eyed one football team supporter! Go the mighty Eagles!
One sidedness means the horses it stiff to one rein and/ or curled on one rein. This is identified by the horse’s inability to correctly follow a circle line or be straight through the body on a straight line.
Normally, if a horse is one sided it would refer to the side the horse was curled to. This means the horse bends too much on that rein to the inside. The corrections are similar to the ones used with a horse that falls out, but perhaps not as strongly because often the line is still being followed, only with too much bend. Use a more supporting outside rein. This will need to be applied until the horse only has the bend for the line he is riding. The outside leg will need to be maintained so the horse continues on the line you want (not normally as strongly as with the horse that falls out). Be careful that the outside leg does not come too far back when applying the aid. This might result in the horse bending the hind quarters more around the inside leg, making him more bent, not straighter. The inside leg continues to encourage the horse forward and provide a support for the inside bend of the body.
This helps correct the horse on “one side”, but we always have two sides: inside and outside or left and right. The one sided horse will not be as willing to travel on circles on the other rein, “his stiff side”. This is similar to the bend/ flexion exercises that involve regular changes of rein. Changes of rein out of the circle, serpentines and decreasing and increasing the circle are great for developing suppleness. This keeps the muscles stretching and contracting on a regular basis. (This helps) Stretching the tight muscles and also means the muscles have periods of rest and activity, therefore not becoming fatigued.
Straightening the horse on the curled side to the outside aids is a very important first step in stretching those inside muscles. This prepares the horse for the change of rein and the greater stretching, when these muscles become the outside muscles on the new rein and even more stretch is required.
The size of the circle line is important, as the smaller the circle the more difficult the horse will find it. So if you are working on correcting a “one sided” problem do not ride circles that are too small. Sizes of 20m and down to 15m are all that is needed in the beginning.
It is always important to remember that we are training the muscles, tendons and ligaments and this takes time. A good rule of thumb is six weeks to start to re-programme and strengthen the horse in the new way of going. During this period, work should be progressive and regular, with rest and stretching periods offered to the horse.
The goal is to have an ambidextrous horse, with even left and right sides