Balance. We often take balance for granted when in fact, the simple act of standing is a complex physiological feat. Let us explore. In a very basic definition of balance 3 main physiological process are evident:
Maintaining balance while standing in the stationary position relies on intact sensory pathways, sensorimotor integration centers and motor pathways.The main sensory inputs are:
- Joint position sense (proprioception), carried in the dorsal columns of the spinal cord;
- Vestibular apparatus
Crucially, the brain can obtain sufficient information to maintain balance if any two of the three systems are intact.
Ok, if you read our blog you should be familiar with the term proprioception, the ability to track your body in space. The 2 other main sources for information our brains need for balance are visual input and vestibular (meaning, inner ear). The organism of the inner ear can help your brain track head movement, another form of spatial orientation. This all makes sense so far…
Let’s dig a little deeper. The brain has to be able to process and synthesize these separate bits of information to help us achieve and maintain consistent balance. In other words, for most people, our brains can quickly process different and changing sources of information to help us function in a gravitational field. So, how quickly? Well, in terms of processing proprioceptive response the slower parts of us is quoted as “up to 100 milliseconds.” There are more rapid systems of neural pathways that carry more specific information (precise localization of touch, pressure, vibration, etc.). The fibers of the swifter system travel the length of the spinal cord, “until they synapse in the medulla oblongata.” The medulla oblongata is the part of the brain referred to as the myelencephalon. (Note: There is a location in the brain, which is the “house” where all gross/big movement is sensed. This house is called the “primary motor cortex.” That’s where movement is first sensed. Processing that information happens later and also in the medulla oblongata to help further facilitate and maintain our balance.) The medulla oblongata is specifically associated with the body’s autonomic breathing mechanism (that’s not connected to balance. Oh wait, yes it is!!!!), but also sits beneath another brain structure the pons. The pons is associated with maintaining balance and often works with the medulla oblongata to regulate breathing (oh, so they ARE connected!).
This very quick review and basic understanding of what helps us maintain balance will help you to understand other blog