Riding is about being in perfect balance with your horse & not interfering or throwing the horse out of balance because the rider doesn’t have their own independent balance. There is nothing more displeasing for either the horse or for the spectator to see a rider who is out of balance with their horse & supporting themselves on the reins as well as banging on the poor horse’s back.
The horses’s back muscles are sensitive & when a rider bangs down heavily on their back it hurts them. You will often see this in the rising trot.
To do rising trot properly & correctly the rider needs to go slightly forward with their upper body & keep their lower leg back & underneath their upper body. This helps to keep the rider in balance with their horse. That way they are going with the horse as the horse trots forward & not getting left behind &
supporting themselves on the reins.
No different really to getting up out of a chair... You don’t stick your legs forward & go back with your body to get up out of the chair! Do you?
No you put your legs underneath you & go slightly forward with your upper body & rise up out of your chair. If you want to sit down on your chair you don’t put your legs forward & go back with your upper body if you did that you would lose your balance & crash onto the chair. Same happens when you sit or bang down on the horse’s back...... Poor horse!
When you go slightly forward with your upper body that doesn’t mean you collapse your core or round your lower back or round your shoulders. It should be the same as if you were standing correctly upright with your shoulders back only difference is you keep that position & go slightly forwards with your upper body.
This is what all riders should be taught from scratch, the correct basics. How to sit in perfect balance with their horses in walk, trot & canter. Not bouncing on their backs, interfering & supporting themselves on the reins.
The reins are there to show the horse where to go & how to go. Not for his support or the rider’s support.