As a rider we all know how important it is for a horse to work in balance. During our horses training us riders need to develop the feel to know when that is happening. We always strive for the horse to push evenly from all four limbs. They are to be equal in how they carry weight on either side.
Majority of horses will to a degree carry more weight on the forehand, through training for some disciplines (dressage being the primary example) we adjust that distribution over a period of time so educating the horse to engage more the hind legs, sit more and thus lighten the forehand.
A horse will not be born equally balanced (nor are humans), like us they can be more one side dominant. During our training of the horses its essential we can feel this and, in turn correct it. We all are aware that a horse working correctly over his back will move more evenly, carry weight correctly and thus also prevent added stress and overload on tendons and ligaments.
Whilst training to improve balance in our horse, so also straightness becomes more correct. During this period the horse would naturally be loaded on one shoulder more than the other. It is often the case that they can be stiffer on one rein. Our aim is to have them feeling even on both sides, and with equal weight into both hands moving with freedom softness and lightness forwards.
Riders often forgo their own development in favour of the horses, however to assist the horse to improve we must also invest some time into ourselves. Part of that is to be aware of our own imbalances. A unbalanced rider cannot ride the horse to their own full potential. A balanced rider will also be in a position to be stable and secure in the saddle. Often it's the unbalanced rider will be more likely to fall off.