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TBI and Concussion Management

TBI and concussion management is one of the "hot" topics today

Browse this reference page to find how posturography can help you manage your patients suffering from these issues, being them caused by sport injuries, motor vehicle accident or other traumatic events.

Posturography

Highlights

Currently, all tests and investigations, with the exception of clinical balance testing, remain experimental.

The CAPS® systems make it possible to have a very fast and objective testing of balance on the sidelines, requiring less than one minute, and without the intervention of highly trained personnel.

Introduction

Posturography equipment is usually used clinically to assess concussion and traumatic brain injuries (TBI).

So far the main criticism has been that posturography can ONLY be used in clinical settings. Hence, non clinical grade and subjective tests have been developed to provide a sideline assessment tool.

With the CAPS® (Comprehensive Assessment of Postural Systems), this is no longer true: they are clinical grade, portable, USB powered, easy to use posturography systems that you can use on the sidelines! And the same technology can be used to assess when an athlete is ready to return to play, by continously monitoring the recovery and rehabilitation progress after an injury and comparing the results with pre-injury baselines for the same subject.

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Background

Sports that involve physical contact are a major cause of head injuries. This is true for hockey as well as several other sports, including, but not limited to, football, soccer, lacrosse and rugby. Unfortunately, many coaches, athletes, parents and trainers do not have the knowledge and specialized training to detect the sometimes subtle symptoms of low level head injuries. According to Schneiders et al. [1] "Lack of knowledge of concussions could therefore be one of the main detriments to concussion prevention".

It is well established in the scientific literature that even mild Traumatic Brain Injuries (mTBIs) affect balance; for this reason, tasks involving balance and coordination are commonly used to determine neurological function in sports-related concussion [2][3]. According to Davis et al. [4] "currently, all tests and investigations, with the exception of clinical balance testing, remain experimental". Unfortunately, balance testing in its current forms requires too much time and specialized training to be suitable for routine and/or sideline testing of athletes. For instance a commonly used balance assessment called Balance Error Scoring System (BESS) requires 6 different test conditions for a total test time of about 3 minutes; it should be repeated 3 times [5] for a total of 9 minutes; it requires 2 persons highly trained in observing postural changes; it cannot be performed with skates or shoes, thus requiring additional time to remove and put them back on; and above all it is subjective in nature because it relies on observation making it somewhat unreliable [6] and capable of detecting only relatively large balance impairments.

Computerized Dynamic Posturography (CDP) instruments could overcome these limitations, but the devices so far used in research were designed for clinical and research labs, and so are difficult to transport, take up a lot of space, and require too much time and specialized training to be effectively used on the sidelines. The main consequence is that only impacts and concussions that produce obvious and immediate symptoms such as headaches, tinnitus (the perception of sound within the human ear in the absence of corresponding external sound), dizziness, disorientation or even momentary loss of consciousness are identified and treated, whereas those head injuries not producing evident symptoms go undetected and untreated, often until their cumulative effect becomes severe and permanent. Parker et al. [7] have shown that "athletes consistently demonstrated gait imbalance even in the absence of concussion. The findings of this study support the supposition that participation in high-impact sports has a measurable and possibly detrimental effect on balance control in the absence of a medically diagnosed concussion". Furthermore, it is well established that "Chronic Traumatic Brain Injury (CTBI) represents the cumulative, long-term neurological consequences of repetitive concussive and sub-concussive blows to the brain and since its treatment options are relatively limited, the prevention of CTBI is of paramount importance and will undoubtedly rely on increasing medical surveillance" [8].

A major limitation of most balance measuring methods and instruments instruments, including most CDP devices commonly used in clinical and research applications, is the fact that they do not possess the metrological characteristics (accuracy, precision and resolution) sufficient to detect small changes in a person's postural control such as those caused by minor impacts and otherwise asymptomatic concussions. As explained in our posturography page, not all posturographic instruments are created equal. Unfortunately, all too few users of balance measuring devices realize the simple fact that the data they obtain are only as good as the instruments used to collect them.

[1] Cusimano MD. "Canadian minor hockey participants' knowledge about concussion." Can J Neurol Sci. 2009 May;36(3):315-20.
[2] Schneiders AG, Sullivan SJ, Gray AR, Hammond-Tooke GD, McCrory PR. "Normative values for three clinical measures of motor performance used in the neurological assessment of sports concussion." J Sci Med Sport. 2010 Mar;13(2):196-201. Epub 2009 Jun 27.
[3] Guskiewicz KM. "Assessment of postural stability following sport-related concussion." Curr Sports Med Rep. 2003 Feb;2(1):24-30.
[4] Davis GA, Iverson GL, Guskiewicz KM, Ptito A, Johnston KM "Contributions of neuroimaging, balance testing, electrophysiology and blood markers to the assessment of sport-related concussion." Br J Sports Med. 2009 May;43 Suppl 1:i36-45.
[5] Broglio SP, Zhu W, Sopiarz K, Park Y. "Generalizability theory analysis of balance error scoring system reliability in healthy young adults." J Athl Train. 2009 Sep-Oct;44(5):497-502.
[6] Finnoff JT, Peterson VJ, Hollman JH, Smith J. "Intrarater and interrater reliability of the Balance Error Scoring System (BESS)" PM R. 2009 Jan;1(1):50-4. Epub 2008 Dec 10.
[7] Parker TM, Osternig LR, van Donkelaar P, Chou LS. "Balance control during gait in athletes and non-athletes following concussion." Med Eng Phys. 2008 Oct;30(8):959-67. Epub 2008 Feb 1.
[8] Rabadi MH, Jordan BD. "The cumulative effect of repetitive concussion in sports." Clin J Sport Med. 2001 Jul;11(3):194-8.

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The CAPS® Advantage

Since the CAPS® force platforms were designed to be highly portable (they were the first posturographic devices and some of the first medical devices in general capable of being run from a battery powered portable computer without requiring any external power source; and they were the first and still one of the few balance assessing tools that do not require any special setup such as leveling of the platform on the floor). Any of our CAPS® systems can be used wherever the need for a balance test or screening might arise, including on the sidelines of a sports arena.

The CAPS® force platforms were also designed to be extremely sensitive and accurate, so they can detect even minute changes in balance that might provide an early indication of changes in a person's body before these become evident and difficult to reverse. This is actually a very important point: just because a device seems to be able to measure sway and hence can assess balance, it does not mean it can do so with sufficient accuracy and precision. When standing still on a rigid surface a person's sway can be 2 mm or even less [9]; furthermore, a change in sway of less than 20% has been reported to be significant [10]. This means that the error in measuring the sway has to be less than 0.4 mm. Since sway is an amplitude within two extreme points, the error in measuring the position of the body has to be less than 0.2 mm, which is actually what the International Society for Posture and Gait Research (ISPGR) standards call for [11]. Few devices currently on the market satisfy the ISPGR standard, but the CAPS® force platforms do [12]. What can happen when devices are not accurate and precise enough is that even major changes go undetected, as a paper by Bernstein and Burkard clearly shows [13].

The CAPS® makes it possible to have a very fast and objective testing of balance on the sidelines, requiring less than one minute, and without the intervention of highly trained personnel. However, since it is also documented in the scientific literature that changes in an athlete's balance can occur because of fatigue, overall physical and mental status [14], as well as training [15][16], regular baselines should be obtained for each athlete to identify how much these aspects affect his/her balance. Furthermore, assessing the athlete's balance just before each game and immediately after high impact collisions common to several sports makes it possible to quickly identify otherwise undetected injuries, particularly head injuries that do not produce evident symptoms. Once an athlete has experienced an injury, monitoring the athlete's balance during the recovery provides coaches, athletic trainers and attending clinicians with an objective and quick assessment of the athlete's readiness to return to competition, rather than relying on the commonly used standard of being symptoms free for 24 hours.

[9] Browne J, O'Hare N. "Development of a Quality Control Procedure for Force Platforms." Physiol Meas. 2000; 21(4):515-24.
[10] Moghadam M, Ashayeri H, Salavati M, Sarafzadeh J, Taghipoor KD, Saeedi A, Salehi R. "Reliability of center of pressure measures of postural stability in healthy older adults: effects of postural task difficulty and cognitive load." Gait Posture. 2011;33(4);651-5.
[11] Scoppa F, Capra R, Gallamini M, Shiffer R. "Clinical stabilometry standardization: Basic definitions - acquisition interval - sampling frequency." Gait Posture. 2013;37:290-2.
[12] Pagnacco G, Carrick FR, Wright CHG, Oggero E. "In-situ verification of accuracy, precision and resolution of force and balance platforms." Biomed Sci Instrum 2014;50.
[13] Bernstein J, Burkard R. "Test Order Effects of Computerized Dynamic Posturography and Calorics", Am J Audiol; 2009 Jun; 18(1):34-44.
[14] van Donkelaar P, Osternig L, Chou LS. "Attentional and biomechanical deficits interact after mild traumatic brain injury." Exerc Sport Sci Rev. 2006 Apr;34(2):77-82.
[15] Schneiders AG, Sullivan SJ, McCrory PR, Gray A, Maruthayanar S, Singh P, Ranhotigammage P, Van der Salm R. "The effect of exercise on motor performance tasks used in the neurological assessment of sports-related concussion." Br J Sports Med. 2008 Dec;42(12):1011-3. Epub 2008 Feb 28.
[16] Fox ZG, Mihalik JP, Blackburn JT, Battaglini CL, Guskiewicz KM. "Return of postural control to baseline after anaerobic and aerobic exercise protocols." J Athl Train. 2008 Sep-Oct;43(5):456-63.

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