Posted by James Rooney on March 28, 2003 at 14:36:57:
In Reply to: Re: proprioception posted by Edith on March 28, 2003 at 13:41:32:
: : : : : I'm quite interested in learning more about the horse's amazing "feats" of proprioception (his awareness of where his feet are). Considering the speed of his movements, the uneveness of ground surfaces, and often the lack of visual stimuli (as when racing in a pack or in the dark) a sound horse will rarely mis-step, and I find this very impressive. I am not so much interested in normal processes, but in how these processes can be interrupted or distorted by injury, or by poor farriery. On the flip side, I'm guessing that normal proprioception can be restored after injury, and improved by good farriery. I come by this interest out of personal experience with a badly sprained ankle. I kept re-injuring it until I "re-educated" it to restore the proprioceptive pathways that had been damaged and began wearing custom-fitted orthotic shoe inserts. The ligaments are still floppy but I don't roll that ankle any more, I can sense it starting to roll and can unload it in time to prevent injury.
: : : : : On a related note most of us have been taught that the shape of the hoof wall will be influenced by where we put the perimeter of the hoof or shoe, and indeed, most of us have observed this to be true empiracally (sp?), but I haven't seen much "true" science on the subject.
: : : : : Also, can blood flow, nutrient uptake, or other metabolic processes within the hoof capsule be affected by changes in proprioceptive efficiency?
: : : : : Lastly, I've always been curious how a horse with a palmar digital neurectomy seems to get around with no problems. I used to ride a nerved horse and she never took a bad step.
: : : : : I'm not sure where my curiousity on this subject is leading to, maybe just my own gee-whiz-type understanding of all things equine, but does it seem to anybody else that this is an important and understudied subject that may lead to something significant and/or interesting? Anybody know of any hard science on the matter or have any feedback?
: : : : : :) Speedy Petey
: : : : Of further interest is the Tennessee Walking Horse that knows where the end of that stack is. If you want to perceive how he does this, simply hold an object behind your back and touch various parts of it. You will find you can do this with relative ease. How do you know where something is that you cannot see and is not a part of you? I'm not sure anyone knows exactly how this works, but it does work.
: : : : M. W. Myers, D.V.M.
: : : You open an enormous and complicated can of worms. Proprioception is not just peripheral; it involves the eyes, the vestibular apparatus of the inner ear, as well as the coordinating centers in the brain. Just to add more confusion or fun, at least, years ago I saw an anesthetized mule in a sling lowered into a pool of water. As soon as one hoof touched water, the mule began to paddle!
: : For what its worth I looked up the following from the American Heritage Dictionary.
: : Proprioception: The reception of stimuli arising within the organism.
: : Proprioceptor: A sensory receptor, chiefly in muscles, tendons and joints, that responds to stimuli arising within the organism.
: : Phil
: First thanks Phil.. I was on my way to look that up!
: Second... do not laugh.... But that is like some people are extreamly aware of their bodies and can stand on anything walk through anything etc etc etc... while other people can not walk and chew bubble gum at the same time. My dad has an Appy that can not even balance on four feet on flat ground. Shoeing has help so now it is only if he tries to move even on flat ground (yes it really can be that bad). He is a walking conformational disaster and can not see in the dark. On the other hand I have a QH mare that could be the next equine bulldozer and you could never spill a drop out of your water glass while she is bulldozing away.
: Then my once in a life time horse went blind in her right eye due to an extreamly rare optical nerve tumor and I did not even know it. She NEVER once missed a step and went through anything and everything. Even when the tumor effected both eyes and she was completely blind.... She would lead like a dream as long as you kept on hand on her neck and when she would get near the trailer she would slow down til she lightly bumped the back of the trailer and then loaded up like a horse that could see.
: Edith
I must add one further comment. The appaloosa mentioned might well have a lesion of brain and/or spinal cord. With this horse or any other acting in such a way, it is quite possible it has a neurological disorder manifesting as ataxia (wobbling) and lack of coordination. This is not primarily a problem of proprioception but, rather, of damage to equililbrium tracts in the spinal cord or centers in the brain. A careful neurolgical examinatin is always in order with any animal with such signs.