Preparation before movement

The importance of activating the deep paravertebral (muscles closest to the skeleton) before activation of the larger superficial muscles (bit of a long sciencey post but I’ve tried to keep it simple!).

I am referencing this information from Dr Nichole Rombach on Motor Control Based Rehabilitation for Equine Spine Dysfunction. One of the topics she discussed was the function of the deep prevertebral muscles and their importance in dynamic stability.

Bear in mind a lot of this information is still mostly anecdotal and primarily based on human studies but it is likely that similar principles apply in the horse.

Nichole explained the theory of Dynamic stability which is achieved by a combination of feed-forward ↪ and feed-back ↩actions.

Feed-forward action is the anticipatory function allowing deep muscles to activate before movement, they ‘prepare/stabilise’ the body.

Feed-back action responds to sensory input from mechanoreceptors, nociceptors (pain), proprioceptors and gives feedback to the brain on where the body is, and how movement should be executed.

Feed-forward and feed-back actions must function together for optimal movement. Dysfunction may occur when feed-forward activation of the paravertebral muscles doesn’t occur, therefore, communication with the feed-back action is lost…therefore stability is lost. When there is a lack of stability, the proprioception mechanism is affected and results in hypo (less) or hyper (more) mobility.

When deep muscles atrophy, superficial muscles tighten to compensate for the lack of stability which should be the primary role of the deep muscles. This is where we may see horses that have overdeveloped superficial muscles, such as the brachiocephalic (underdeck muscles) as they now need to work as stabilisers AND movers, which they are not designed to do (this also has to do with muscle fibre type but I won’t delve into that). This is also why these muscles are often sore as they are working over time.

If you’re completely lost after all of that, in a nutshell, the deep skeletal muscles are important for stability and need to be activated first in order to complete a larger motion. This can be achieved through slow and specific exercises which I am able to teach you during a session (shift back and rebalance is a common one I teach). Think of it as strengthening the chassis of a car so the wheels can turn and move safely and easily. Below is an image highlighting some of these larger superficial muscles and some of the paravertebral muscles in the neck.