I've heard people say it's bad too. But as far as anything we do to our horses while riding, I really don't think it's going to do much harm.  I'd imagine that people say it's hard on their back, tendons, and ligaments....but so is cutting, reining, dressage, jumping....and on and on it goes. Learning to properly mount a horse is important.  Even a well broke horse can get sour to mounting if someone does it rudely every time whether the horse is parked or not.  My friend's horse knows to stand by tailgates or picnic tables.  That works well for all involved.

Amanda

I once met a lady who was crippled. She mounted her horse by having it lay down, where she climbed on and asked the horse to get up. They had a long and happy relationship. I'm sure it was different for her horse to get up with an extra 120lbs vs getting up with me on it's back. He weight didn't seem to cause any long term problems

When I was doing CTR I taught my horses to move over next to objects so I could stand on the object and mount. It was fairly simple to teach and the horses learned it very quickly. Ken McNab demonstrats it on one of his RFD-TV programs.  I stand by the fence and depending which arm I raise, I kiss and the horse will rotate either right left 90* to become parallel with the fence. I stand on a fence rail and mount. But it works just as well with a fender of the trailer, a rock, a log and ditch  etc.

Thanks for your input, however, I'm not sure why you would take from my question that I do not properly mount a horse.  My horse is very well behaved and stands still for mounting.  While I said I appreciate a horse that parks for mounting, let me be clear, I do not park my horse for mounting. When I ride my husbands much taller horse there are several things I do to make mounting easier; putting the horse in a downhill position in relation to myself, use a picnic table bench or a downed tree on the trail.

Perhaps my question was not stated clearly.  My question is: how does parking a horse to mount impact the horse?