Window 2: Balance / Posturography for Concussion ManagementWritten By: David Burns
Balance testing with advanced technologies rather than simply “eye balling” it, is the best way to accurately gain a “window” into the vestibular or “balance” system. Thankfully, new technology like the CAPS force plate from Vestibular Technologies, provides a very fast and valid assessment tool for detecting even low grade concussions.
Sophisticated force plate technology, like the CAPS unit, can identify postural stability deficits lasting approximately 72 hours following sport-related concussion. “It appears that postural stability testing provides a useful tool for objectively assessing the motor domain of neurologic functioning and should be considered a reliable and valid addition to the assessment of athletes suffering from concussion…” (Paul McCrory, 2009).
While understanding the level of function of your balance system is important as a measurement for concussion, it is also key to preventing concussion injuries. Areas in your brainstem and cerebellum receive information that is vital to balance. This information comes from the joints, muscles, inner ear and eyes. One area where this information is compiled is the “vestibular nuclei” in the brainstem.
Vestibular nuclei have descending tracts (i.e. MLF) that go to the smaller stabilizing muscles of the spine (i.e. shunt muscles). Shunt muscle integrity or function in turn influences the “moving muscles” (i.e. spurt muscles). Poor shunt stability equals weak spurt activity. Now with decreased stability of the spine from shunt muscles and general decreased strength of the moving bigger stabilizing muscles of the neck we have increased risk for concussion.
Without spurt and shunt activity your head would be like the “bobble heads” you get at a baseball game. It is like watching a baby trying to support their head. It “bobbles” around because of a lack of stability. If you begin to observe players on the field you will note differences in head stability. Any movement of the trunk or contact to the head and the degree of whipping action will be increased. This whipping action is not good news for the brain which will be jostled inside the skull.
Now the integrity of your balance is not necessarily going to be the same in all body or head positions. This is why it is important to test and measure balance is various postures. Often times a person’s balance can be decreased in a specific posture, for examples with their head back in extension.
OK, so if we know that our balance reflects what our vestibular nuclei are doing. And if we know that our vestibular nuclei send signals to our shunt stabilizing muscles and we know that stabilization is important for concussion prevention. It should be clear that in order to decrease risk of injury, we want to improve our balance in that given posture.
Now, if a players balance is decreased with their head in extension and by association they have decreased stability in this position what is their risk while they go up for a header or to catch a ball, whether that be a football, baseball or basketball? Exactly! They are more at risk.
Decreased balance = decreased joint stability = increased risk of concussion.
This blog and the other blog “windows” into brain function are not intended for anybody to make any diagnosis or determine treatment for anybody. It is simply intended to help patients understand what a functional approach to neurology, brain function, concussion management, sports performance evaluation may entail. But most importantly, to help the patient or client communicate with the provider so that they or their children can achieve the best brain health possible. Achieving optimal brain health is an interdependent process, an active process that starts with communication.