BY: PHIL PALMER
In the current climate of the ‘Wild West‘ of concussion clinics, many tools are being used to assess this type of serious injury, also known as traumatic brain injury (TBI), or acquired brain injury.
Assessments can include physical and mental status examination, Glasglow Coma Scale, Immediate Post-Concussion and Cognitive Testing (ImPACT) computer-based system, Balance Evaluation Scoring System (BESS), Inertial Sway measuring devices, and Optogait assessments.1-3
Each assessment method is designed to evaluate the different aspects of the complex physical, cognitive, emotional and sleep disturbances that can result from a concussion4.
Establishing a ‘baseline’ with patients before a concussion occurs is useful in evaluating a person post-concussion to determine how the injury has affected them.1,3,5 This is not always possible given how and when a brain injury can occur. An assessment baseline can always be performed when commencing treatment and as an introduction to a rehabilitation program.
One tool we are using to establish a person’s pre-injury baseline is the Optogait, which is considered a ‘gold-standard’ device for measuring gait (how a person walks), balance and movement symmetry.6-9
The simple 30-60 second test of walking on a treadmill can be recorded by a computer system using lasers to establish the individual characteristics of the patient’s gait, which can then be remeasured throughout the rehabilitation program.
The amount you move when standing still, (your postural sway) is measured by 3D accelerometers (which track acceleration), gyroscopes (which track orientation), and magnetometers (which, according to the journal, Karger, ‘measure the ‘magnetic fields emitted by the brain, generated by neuronal activity)10. These tools allow a much more precise measurement of sway – up to 1,000 times per second more – compared to the manual use of a stop watch.
We also determine the speed of cognitive processing during walking by testing patients walking while counting backwards. The eyes and head together (Vestibular Ocular Reflex) are tested in order to determine concussive symptoms.
These tests are useful when a patient may feel their concussion symptoms have resolved, but in fact their cognitive processing is still poor.
The Gyko component of the protocol also tests sway, which is the movement of the centre of mass, and upper vs. lower body plus compensatory movement patters made by the brain to return to a normal set point so it would make sense that the tests are not highly correlated like the march in place and BESS, performed using the OPTOGAIT.
At Genesis Rehabilitation, Physiotherapy and Sports Injury Clinic, where I am the clinical director, we also use the Gyko system to determine changes in physical functioning with changes in body position.
More recently, a validation study was conducted to utilize the Optogait® equipment for evaluating the march-in-place test traditionally used for vestibular (inner ear) testing, called the Fukuda or Unterberger Stepping Test.3,13-15 This study validated BESS testing, but was not highly correlated to the ImPACT testing.3 ImPACT does not specifically measure various aspects of balance, postural stability, or a physical asymmetry, so it would make sense that the tests are not highly correlated like the march-in-place and BESS.
ImPACT is widely used because of the ability to use a computer in the field to perform the assessment, however recent validity studies on ImPACT suggests that approximately 20% of the time underperformance of the test in group/team settings may result in athletes returning to play too soon.2,16 This error creates the ability of a patient to, in a sense ‘cheat’ on their baseline test, so in the event of a concussion they can return to play faster, since their post-concussion score would be low and close to the baseline score.17
Using objective physical characteristics of the pathophysiology of TBI, the data collection with the OPTOGAIT equipment cannot be easily altered by the patient, thus “ you can’t cheat” testing of gait, postural sway, or marching in place tests with your eyes open or closed.
Dr. Philip Palmer is a chiropractor serving Toronto and the surrounding area. He is the clinical director of Genesis Rehabilitation, Physiotherapy and Sports Injury Clinic.
- Hirsch MA, Grafton L, Runyon MS, et al. The Effect of Cognitive Task Complexity on Postural Sway in Adults Following Concussion. Archives of Physical Medicine and Rehabilitation. 2015;96(10):e51.
- Gaudet CE, Weyandt LL. Immediate Post-Concussion and Cognitive Testing (ImPACT): a systematic review of the prevalence and assessment of invalid performance. The Clinical neuropsychologist. 2017;31(1):43-58.
- Engelson MA, Bruns R, Nightingale CJ, et al. Validation of the OptoGait System for Monitoring Treatment and Recovery of Post-Concussion Athletes. Journal of chiropractic medicine.
- Harmon KG, Drezner JA, Gammons M, et al. American Medical Society for Sports Medicine position statement: concussion in sport. British journal of sports medicine. 2013;47(1):15-26.
- Alberts JL, Hirsch JR, Koop MM, et al. Using Accelerometer and Gyroscopic Measures to Quantify Postural Stability. Journal of athletic training. 2015;50(6):578-588.
- Lienhard K, Schneider D, Maffiuletti NA. Validity of the Optogait photoelectric system for the assessment of spatiotemporal gait parameters. Medical Engineering & Physics. 2013;35(4):500-504.
- Lee MM, Song CH, Lee KJ, Jung SW, Shin DC, Shin SH. Concurrent Validity and Test-retest Reliability of the OPTOGait Photoelectric Cell System for the Assessment of Spatio-temporal Parameters of the Gait of Young Adults. Journal of physical therapy science. 2014;26(1):81-85.
- Gomez Bernal A, Becerro-de-Bengoa-Vallejo R, Losa-Iglesias ME. Reliability of the OptoGait portable photoelectric cell system for the quantification of spatial-temporal parameters of gait in young adults. Gait & Posture. 2016;50:196-200.
- Ammann R, Wyss T. Comaparison of Three Gold-Standards to Measure Ground Contact Time in Runners. SPORTWISSENSCHAFTLICHE. 2011.
- Neville C, Ludlow C, Rieger B. Measuring postural stability with an inertial sensor: validity and sensitivity. Medical devices (Auckland, NZ). 2015;8:447-455.
- Iosa M, Morone G, Bini F, Fusco A, Paolucci S, Marinozzi F. The connection between anthropometry and gait harmony unveiled through the lens of the golden ratio. Neuroscience letters. 2016;612:138-144.
- Iosa M, Bini F, Marinozzi F, et al. Stability and Harmony of Gait in Patients with Subacute Stroke. Journal of Medical and Biological Engineering. 2016;36(5):635-643.
- Zhang YB, Wang WQ. Reliability of the Fukuda stepping test to determine the side of vestibular dysfunction. The Journal of international medical research. 2011;39(4):1432-1437.
- Honaker JA, Boismier TE, Shepard NP, Shepard NT. Fukuda stepping test: sensitivity and specificity. Journal of the American Academy of Audiology. 2009;20(5):311-314; quiz 335.
- Grommes C, Conway D. The stepping test: a step back in history. Journal of the history of the neurosciences. 2011;20(1):29-33.
- Maerlender AC, Masterson CJ, James TD, et al. Test–retest, retest, and retest: Growth curve models of repeat testing with Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). Journal of clinical and experimental neuropsychology. 2016;38(8):869-874.
- Schatz P, Glatts C. “Sandbagging” baseline test performance on ImPACT, without detection, is more difficult than it appears. Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists. 2013;28(3):236-244.
PHOTOS: Optogait Technologies Inc.