Stride length related to a horses shoulder conformation?

Question
Hi,
I have heard in the past that a horse with a more sloping shoulder will have a longer, smoother stride and a horse with a more upright shoulder will have a shorter, choppier stride.  I read on this website that it's the not straightness of the shoulder at all, but it's the angle of the humerus and scapula and the size of the humerus in relation to the scapula.  However, I have no idea how to identify where each bone begins and ends!  I am looking at this horse as a possible purchase, and would appreciate it if you could take a look and see how his stride will be based on his shoulder (I originally thought that his shoulder was upright so he would have a short stride, but I would love to know how to determine the stride of a horse based on a picture like this one):

http://i163.photobucket.com/albums/t316/yellowjacket988/jumpingpicturesandrocket...

Thank you!

Answer
Hi Caroline.
  You don't mention what breed this horse is. In the Standardbred, there are many things that influence gait, including pedigree and shoeing. There is really no way to determine gait from a picture of a horse standing in an aisleway. I would suggest taking him on a test ride, or at the very least working him on a lunge line.
  Here are a few sites that may help you with equine anatomy:
http://en.wikipedia.org/wiki/Horse_anatomy
http://vetmedicine.about.com/od/equinehorseanatomy/Equine_Horse_Veterinary_Anato...
http://www.allabouthorses.com/horse-health/injuries/horse-anatomy.html
http://www.equisearch.com/horses_care/health/anatomy/

  Hope this is enough info to get you started.
Anne Stepien