Hello, and welcome to Dr. Bartoe’s blog. This first blog post is inspired by a recent patient of ours. He is a 67-year-old male who felt unstable when walking and standing. It is not uncommon for us to see balance problems showing up as we age, but let’s take a look at what was creating the problem. With an examination, we found that he had difficulty processing information in his cerebellum, the part of the brain that coordinates movement, and he had a decreased amount of proprioception (feedback from his body). Reading that explanation, balance may sound a bit difficult and complex. While it is complex, we can break it down into parts and make sense of it. In the next few posts, we will explore the basics of balance, the three systems involved in balance, and then discuss some methods we can use to improve balance.
Balance is the brain’s ability to keep your body upright against gravity and to keep you moving to where you want to go, but balance is only one example of how our brain keeps our movements efficient and effective. We can see balance in every movement we make, from something as simple as reaching an arm out in front of you to pick up an object all the way to performing incredible acrobatic feats. Each of these actions requires coordination of the muscles in our body. Without this coordinated control, we would be unable to move with any speed or stability, let alone carry out the complex tasks that we do every single day: brushing your teeth, carrying a bag, standing on a boat or lifting your child.
There are many ways that problems with balance and coordination can appear. Looking back at our patient, he felt unstable. This often presents with a sensation of walking on a boat; the world around you swaying back and forth and keeping you off balance. Other presentations include vertigo, which is a spinning sensation, or the feeling of being uncoordinated in certain movements. We see this in patients who often run into corners, drop things, or even have a hard time playing sports and learning new skills. Understanding how these problems have arisen requires us to understand how the brain controls our movements.
Let’s take a look at what goes into moving through a simple activity. In our example of reaching an arm out to pick up an object, there is much more happening than we can see at first glance. In this example, your first thought of balance or coordination may have been focused on the movement of the arm. This makes sense as it is moving and requires a great deal of coordination to carry out smoothly. This is only half the story though. Before we can even move that arm through space, we must create a stable foundation to keep us upright while we move. As our arm raises out in front of us, we shift the weight of our arm away from our center of pressure (our center of balance). If you have seen a seesaw before, you know that as you add weight away from the center point of an object, gravity pulls down on that side. If we fail to create a stable base, we would fall over. In order to keep ourselves stable, the brain engages muscles along our spine, in the core, and all the way down through our legs and feet. Only once we have created a stable base do we move our arm to grab for the object.
The amazing part of the brain that carries out this incredibly complex organization is the Cerebellum. The cerebellum is an area of the brain located on the back and bottom of our cortex (brain). This “little brain” as the cerebellum’s name translates, composes only 10-15% of the brains mass while containing more than three times the number of neurons (brain cells) as the entire cortex. This shows the incredible amount of work that has to be done to keep us moving smoothly.
In order for the brain (including the cerebellum) to create movement of our body, it must first know where we are positioned in space. If we know where we are starting from, we can figure out the best movement pattern to make our movements accurate and energy efficient. A movement pattern is a series of muscle contractions from many different muscles carried out quickly in a set order to create the intended movement. If we are not able to tell where we are in space, we cannot create accurate movement patterns and end up having to correct our movements as they go wrong. Then to compound the problem, since we still can’t accurately tell where we are in space, each correction is off and we must correct repeatedly. We can see this easily in a finger-to-nose test (commonly referred to as a dysmetria test or “inappropriate movement” test). This is that test you see officers performing on suspected drunk drivers. The person reaches their arms out in front of them and tries to touch their nose with the tip one finger while keeping their eyes closed. The person’s hand may shake and fail to move in a straight line if they cannot coordinate appropriately. This is why having a means of measuring where the body is in space is so important.
In the next post, we will explore the three systems of balance. The three systems are 1. The Eyes, 2. The Vestibular System (inner ear), and 3. Proprioception (feedback from the muscles, joints, and skin). The brain takes in information from all three and combines it to get a clear picture of where we are in space. We will take a look at what happens when they fail to tell the brain the same information and in our last post, we will begin to move toward treatment options for balance disorders. For more information, please contact us.