I got it from a popular drug therapy I was on in 1998, called Lupron. Anyhow, I have four wonderful horses. I didn't realize you had them too. I haven't stopped riding by any means. I just do what my pain allows me to do.
Riding is an excellent form of exercise, and works various joints and muscles.
Working these joints helps provide lubrication to keep them functioning well. If you had severe crippling osteoporosis then yes I might say ride only on a leadline or on a very slow, short, safe horse. But as far as I know that's not the case with you. You'd probably do yourself more harm than good, both physically and mentally. If it makes you feel better, purchase some shinguards and a body vest that barrel racers wear.