Bourassa & Associates Rehabilitation Centre
What is the Vestibular System? How does that relate to Balance? And what happens to it with age?
By Leah White B.Kin., M.P.T., C.A.F.C.I.
Q: What is the vestibular system? How does that relate to balance? And what happens to it with age?
A: The vestibular system comprises our peripheral vestibular apparatus and our central nervous system. The peripheral vestibular apparatus includes the inner ear and the associated nerve (the vestibulocochlear nerve) that connects it to the brain. The inner ear organ provides information about acceleration (e.g., taking off in an airplane) and rotational speed (e.g., bending, rolling over, looking up at the sky) of our body in space. The central nervous system (the brain and spinal cord) takes this information and combines it with signals from various sensory organs in our body including our eyes, and our muscle and joint receptors, particularly in our feet and neck, to create stable balance and vision. In short, the three most important components of balance are our visual system (eyes), our vestibular system, and our proprioceptive system (joints and muscles). Problems with balance can produce symptoms like dizziness, vertigo, nausea, blurred vision, and unstable gait, among others.
As we age, structures degenerate in all aspects of our body at varying rates. We can also succumb to various disease processes that cause decreased function in the affected organ. Changes in muscle and joint flexibility can affect the ability of the receptors to send appropriate signals to the brain about joint position in space and also limit our ability to respond to those changes and maintain our balance. For example, the majority of people will begin to experience decreased range of motion and strength in the ankle joint as they age. This lack of mobility limits the body’s ability to accommodate to perturbations in our balance and makes us prone the falling.
Disease processes like glaucoma or macular degeneration can impact the visual input that our brain relies on to determine our body position relative to the horizon. As a result, we are forced to rely on the other two major components of balance listed above; our inner ear and our joint receptors. This may require us to use a gait aid like a cane for extra tactile feedback with the ground which creates more proprioceptive input for our balance system to rely on. Or, we may walk slower, take shorter steps and not lift our feet as high which can again make us prone to falling, especially if we have to rush unexpectedly to the washroom or to answer the phone or doorbell.
Alternatively, tiny particles can become dislodged in the inner ear and cause our peripheral vestibular apparatus to lose its ability to determine which way is up and makes us feel as though the world is spinning. This dizziness can be nauseating and debilitating or it can be a mild annoyance. If you believe you may be experiencing any of the above, or simply believe you have poor balance, contact a physical therapist in your area that has specific training in vestibular and balance dysfunction. They can help determine why you may be dizziness and help devise a treatment plan to assist with your problem.