This gorgeous post reveals how we might view our horses as we do ourselves when going back to work after injury, or time off, and also how we might listen to what our horses are telling us when they say no in the ways they can.
We've had our own experiences here with this kind of thing. A pony who needed acupuncture stopped jumping. A QH with PSSM stopped moving. A Hanoverian who needs his chiropractor stamps his hoof when his hip is brushed.
All of these could be viewed as "disobedience" or "bad" behaviors, and yet these are all good-natured, willing horses. They tell us things with their bodies, they do not use words. A wonderful vet once told me: Assume every negative behavior comes from pain.
The next question to ask is what's wrong? What's going on? I can all but guarantee you that if you stop and ask this question the horse will give you more information, but first he will drop his head and touch you with his muzzle and say thank you for listening.