miniature horse riding

Question
I am a fairly new mini owner.  My question is I adopted a mini two years ago who they said was broke to ride and drive.  Well he drives beautifully and we have been showing for two years, but my question is how the heck can i find out if he is really trained to ride, without putting a young child on his back?!

Answer
Hi,
Because he is trained to drive, even if he wasn't trained to ride, he (probably) wouldn't have much of a problem with riding.  I would get a saddle on him and watch his reaction.  If he's like- "What is this?", I would assume he isn't trained to ride.  If he's okay with it, put a little weight on his back, and see how he does with that.  If he is fine with this too, I would have a younger child sit on him (make sure they wear a helmet just in case, and it wouldn't hurt to have a helper support them) and lead him around.  Then have the child take up the reins and try riding, just make sure you keep a hand on the lead.  
If you need any more info, I'd be happy to help!
~rb