Pain, proprioception, performance and patterns of movement

Some helpful person (I think it may have been Jane Holderness again!) shared a very interesting article on Facebook and it got me thinking. The article is written about human movement and biomechanics but the principles are equally appropriate when considering horses and - more importantly - rehabilitation from lameness.

"Improving your proprioception is an excellent goal for anyone who wants to improve sports performance or reduce pain. In fact, I would claim that any therapy or training method that can achieve either goal efficiently works primarily by improving proprioception. "

 The twin goals of improving performance and reducing pain are absolutely key to rehabilitating the horses who come here and I have thought for several years that the tracks and the different surfaces we use are vital.

In fact, one of the main benefits of our tracks is that they improve proprioception - its something I blogged about in 2009, as our experience with the horses here exactly coincided with the rehabilitation which Prof Jean-Marie Denoix and Jean Pierre Pailloux wrote about in their book "Physical therapy and massage for the horse".

They explain that restoring correct movement can be achieved by the horse moving over different types of terrain. The different surfaces, stimulation and sensations boost proprioception and "eventually lead to soundness of movement".

This is also why I encourage owners to work on varied terrain with their horses when they go home - and why I discourage the use of hoof-boots unless there is no alternative. Proprioceptive input is vital and, particularly following injury or long-term lameness, the horse needs the best possible proprioceptive input - and the best proprioception comes from hard-working bare hooves.

As the article points out, the proprioceptive maps in the brain depend on regular, consistent stimulus in order to keep them maintained and functioning at their best - use it or lose it!

There is a close relationship between pain and proprioception, too.

I've seen with horses who've been here that their soundness can improve rapidly as proprioception changes; nevertheless, although they are sounder, extensive damage to tissue and bone cannot have completely healed in a 12 week time frame.

Equally, trauma apparent on x-ray or even MRI is no indication of how lame a horse may be. Delicate flowers with mild injuries may be as or more lame than tough old troopers with extensive damage.

One explanation comes here, another article from the same blog:

"Pain is created by the brain, not passively perceived by the brain as a preformed sensation that arrives from the body. When a body part is damaged, nerve endings send a signal to the brain containing information about the nature of the damage. But no pain is felt until the brain interprets this information and decides that pain would be a good way to encourage you to take action that will help protect and heal the damage. 

The brain considers a huge amount of factors in making this decision and no two brains will decide the same thing. Many different parts of the brain help process the pain response, including areas that govern emotions, past memories, and future intentions. Therefore, pain is not an accurate measurement of the amount of tissue damage in an area, it is a signal encouraging action. "

The author is talking about the human body, but wouldn't it make sense, in horses too, that if proprioception improves, biomechanics change and stress and damage to tissue is reduced - then pain (and lameness) may correspondingly reduce or even disappear - before healing is complete?

This is a huge subject and is undoubtedly one I will come back to soon :-)