Our Sense of Balance
How Balance Works
Balance is the ability to maintain an upright position. Coordination is the capacity to move through a complex set of movements while maintaining balance. Balance and coordination depend on the interaction of multiple systems in the body including the vestibular (inner ear), visual, and proprioception (referred to as your “touch and feel sense”) systems. Two particular areas of the central nervous system, the brainstem and cerebellum, receive and process the data obtained from the three sensory input systems. The result of this “central processing” is a coordinated response that allows us to maintain our balance and stability.
The vestibular system
The vestibular system constantly monitors the motion and position of our head throughout all normal daily activities. The vestibular system is housed within the right and left inner ears. Within each inner ear are two sets of “labyrinths” – structures that contain a series of canals and cavities – one located inside the other.
Each inner ear labyrinth contains the five individual organs responsible for generating information about head movement and head position. They are the “otolithic” organs (utricle and saccule) and the “semicircular canals” (anterior, posterior and horizontal). The otolithic organs primarily sense linear (forward, backward, sideways) movement as well as tilt of the head. The semicircular canals primarily sense angular (rotation around a center axis) movement of the head.
Nerve fibers from the inner ears send balance information to the brain. Within the brainstem these nerve fibers participate in an extensive neural network involving nerves from the eyes, the cerebellum, and the positional receptors or “proprioceptors” located in the feet, legs, trunk, arms, and neck. The brain interprets this information, making modifications in eye, head and body position to maintain a fixed eye position, and erect posture.
From birth, we tend to rely heavily on vestibular cues during movement and activities. Damage to the vestibular system, caused by a variety of illnesses or injuries, can alter the information being sent from the inner ears to the central nervous system. This will often result in dizziness, vertigo, nausea or unsteadiness.
The three primary balance systems (vestibular, visual, and proprioception) send signals to each other as well as to the brain about head and body movements. As the brain interprets these three input signals, it generates one specific response that is sent back to the muscles of the body to keep us stable, upright, and focused on the target of our interest. Balance is best when the signals sent into and out the brain are fast and accurate. If one of the systems involved in this process is damaged or adversely affected in any way, the other systems must work to compensate for the loss in order to keep us balanced. Temporary loss of one of these systems can result in postural or visual instability. For example, signals from a damaged vestibular system can result in impaired perception of body movement or position. This could also cause visual blurring during movement due to the loss of higher level eye reflex function. Disorders involving the visual system and proprioceptive system can also result in balance related problems.
When these symptoms are experienced, regardless of age, it is essential to see a qualified inner ear specialist and obtain a complete evaluation (with specific balance-related testing) to determine the exact cause of the symptoms and to determine an objective treatment course of action.
If you or a loved one are suffering with balance issues, please contact us today so that we may help you begin on your path to restoring balance.