Question hello Lyn. are we riders spoiling the horse spine riding bareback?
As long as the horse is mature, no. The horse's spine is the last part of the skeleton to fully ossify (turn to all bone) and that doesn't happen until the horse is 8 yrs. old. Skeletal damage to the spine wouldn't happen in a mature horse riding bareback but with an immature horse the possibility exists. Weight is generally carried on the big muscles on either side of the spinal processes which are the bumps you can see on the backs of thin horses. The spinal column is supported by these muscles and associated ligaments. This is what the saddle tree sits on and what the rider's thighs rest on. A saddle tree sits on these and distributes the rider's weight over a broader area than just where the rider sits as when riding bareback. One reason why that is the only piece of tack that is required for distance riders. You can ride in any kind of saddle that works for you and the horse; bridles are not required, I know people who ride in halters. Kinder to the horse when riding for long periods of time to use a saddle. But an hour or 2, no big deal.
Horseman of over 50 yrs., certified equine massage therapist, trainer both riding and driving, long distance trail riding and driving. Both endurance and competitive trail riding and driving.
Organizations American Endurance Ride Assn., Eastern Competitive Trail Ride Assn., New Jersey Trail Ride Assn., Aromatherapists International, American Mustang and Burro Assn., United States Trotting Assn., Standardbred Pleasure Horse Org., US Wild Horse and Burro Association