Question: We have no problem - my horse is fantastic. One question concerns me - I have heard within RM breed association discussions that the young horse should not be trained until the knees are closed.  My horse has been broke for about 10 months - since he was about 2 1/2 - and his knees still haven't fully closed.  He hasn't been used very much at all until I got him, now we try and go out trail riding 4-5 times a wwek for 1 1/2 - 2 hours.  

I'm trying to build up his fitness level but we don't do  hard riding - just enjoyable pleasure rides...should I be worried about his knees and might he experience trouble later on in
life?  Thanks for taking the time to answer this question.

Susan

Yours would be  a rare horse indeed if his knees are not closed by this age.
They are almost always closed by age 2 1/2. ... The rest of him, however, is still growing.  Most importantly, his back (spine) will not be fully formed until he is 6.  Think of what weight on his back may do to those still growing parts, and be sensible in your riding routine.

As to future problems -- his conformation, his general health, and his nutrition levels as a youngster will all play a part in whether on not there are soundness issues.  Certainly plenty of horses are ridden at 2 1/2 and even younger without obvious trouble later in life.  Then there are the others which do exhibit soundness problems due to stress on immature bones
and tendons.  If you are worried, have a good veterinarian, one with some interest and knowledge of biomechanics,  do a complete exam with radiographs to see if there is damage in the knees or other joints.
 

Lee Ziegler