What you describe doesnt sound like RDA stuff to me. Or not yet.
It sounds pretty typical of riding in old age - what I experienced starting to ride aged 62, already with degeneration of my lower back.
The problems are not insurmountable and many have been discussed on NR in the past. I can only describe what I have done and what works for me.
First, on medical grounds - there were stages when my back was so bad that i couldnt sit on a normal chair without pain. In these circumstances clearly you shouldnt ride as it will be equally painful in the saddle. You need to have physio, get special seat supports, learn to manage your back and think of riding only when you are coping with daily life. I was told by my consultant not to ride, but I eventually decided to try it and found that it has been good for my back, especially rising trot.
But before encouraging you to soldier on, I must warn you that I do things in moderation. I dont walk too far before loosening up with rising trot (so a 2 hour Western trail ride is hard).
I dont canter sitting too far or canter far on two consecutive days.
The first imperative is to have a horse or pony that is not too wide in the barrell - you need to be able to sit straight across the horse, with your two knees even, not one further forward than the other. This is true for all older people. some broad backed ponies or cobs may be hard to ride, so the fact that you own a pony already may be creating a problem?
I find my weight is a factor too. if I put on weight the bulk of my thighs adds to the width of the horse.
Having short stirrups can also put more pressure on the base of your spine. A good RI let down my stirrups. You dont want to ride in a "frog" position.
Some of the pain in your hips and legs may be referred pain from your spine. it is with me, but it depends on the state of your hips. It hurts me if I put too much weight on my left hip when riding - so I automatically ride crooked to escape the pain. Horses dont actually mind this at all, but one needs to be aware of ways in which one is adjusting one's seat , and then compensate with other correcting aids if the horse too goes crooked as a result.
Next the saddle. A high cantle makes it hard to sit comfortably without putting pressure on the base of one's spine. My favourite riding school hack has been given a different saddle which is too small for my bottom. But since you own your tack you could find one that is comfy for you. I have ridden one or twice in a treeless saddle but personally at various schools have found a GP saddle or soft dressage saddle just fine. It is not something that really strikes me unless the saddle hurts me.
To reduce the wear on my joints I ride in Sprenger stirrups. I also try to alternate sitting in walk and canter with rising trot and forward seat which removes the weight from ones spine. I turn up at the yard disgracefully late -the consultant said not to take exercie before mid morning, so my body had a chance to loosen up first.
For mounting and dismounting (dismounting especially) there have been recent detailed threads. As I have posted many times, the Pony Club Handbook gives instructions for less able bodied people to dismount with the help of the left foot remaining in the stirrup until the right leg has cleared the cantle. My OH and I have never dismounted any other way. Please look at the recent thread.
My OH didnt start riding till he was 67 and we are now 71 years old, so we regard all these things as normal. Your medical condition is something on which I cant comment. But degeneration and increased crookedness is very common in old age and far more attention needs to be paid to providing happy riding for the elderly. There is so much for children and for the disabled, but next to nothing for us. Our teacher is one of the few who takes it seriously and taught one beginner who was already 70 years old.
It could well be that you need someone similar to help you. Dont go to any old riding school who will sneer at you and wring their hands and say its impossible, which is what happened to me.
You dont say where you live? But if you want to ride, there is hope and the RDA should not be your only option.
