Sway Research

Normative Data for the Sway Balance System

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AUTHORS: Brett, Benjamin L., PhD; Zuckerman, Scott L., MD, MPH; Terry, Douglas P., PhD; Solomon, Gary S., PhD; Iverson, Grant L., PhD

OBJECTIVES: Static balance, postural stability, and reaction time are commonly impaired after a sport-related concussion. The Sway Balance System assesses postural sway (ie, stability) and simple reaction time using the triaxial accelerometer built into iOS mobile devices. The purpose of this study was to provide normative data for children and adolescents and to examine for age and sex differences on the Sway Balance System.

CONCLUSION: Age and sex are important factors to consider when assessing Balance and Reaction Time scores using the Sway Balance System’s Sports protocol in youth. We provide age- and sex-based normative values for the Sway Balance System, which will likely be helpful when using this technology to assess and manage concussions.

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Reliability and validity of a motion-based reaction time assessment using a mobile device

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AUTHORS: Mark Burghart, Jordan Craig, Jeff Radel & Jessie Huisinga

ABSTRACT: Information processing speed is often altered following a concussion. Few portable assessments exist to evaluate simple reaction time (SRT) in hospitals and clinics. We evaluated the use of a SRT application for mobile device measurement. 27 healthy adults (age = 30.7 ± 11.5 years) completed SRT tests using a mobile device with Sway, an application for SRT testing. Participants completed computerized SRT tests using the Computerized Test of Information Processing (CTIP). Test–retest reliability was assessed using intraclass correlation coefficients (ICC) between Sway trials. Pearson correlations and Bland-Altman analyses were used to assess criterion validity between Sway and CTIP means. ICC comparisons between Sway tests were all statistically significant. ICCs ranged from 0.84–0.90, with p-values <.001. A one-way analysis of variance (ANOVA) revealed no significant differences between trials (F3,104 =  1.35, p = .26. Pearson correlation between Sway and CTIP outcomes yielded a significant correlation (r = 0.59, p = .001). The mean difference between measurement methods was 43.7 ms, with limits of agreement between −140.8–53.4 ms. High ICC indicates Sway is a reliable method to assess SRT. A strong correlation and clinically acceptable agreement between Sway and the computer-based test indicates that Sway is suited for rapid administration of SRT testing in healthy individuals. Future research using Sway to assess altered information processing in a population of individuals after concussion is warranted.

Sway Balance Mobile Application: Reliability, Acclimation, and Baseline Administration

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AUTHORS: Mummareddy, Brett BL, Yengo-Kahn AM, Solomon GS, Zuckerman SL

OBJECTIVES: To describe historic baseline session administration practices, to assess the utility of a practice trial (an acclimation trial) before the official balance session, and to examine the within-session reliability of the Sway Balance Mobile Application (SBMA).

RESULTS: Variable administration practices with significant differences between baseline session averages across methods were found. Individuals who performed an acclimation trial had a significantly higher baseline session average than those who did not. Within-session reliability estimates were in the low to adequate range (r = 0.53-0.78), with higher estimates found for 2 consecutive baseline tests (r = 0.75-0.78).

CONCLUSION: For maximum clinical utility, a standardized protocol for postural control baseline acquisition is necessary. Acclimation trial should be administered before a baseline session to minimize variability, especially with only 1 to 2 baseline tests. The highest reliability was observed across 2 consecutive baseline tests within the same baseline session. We suggest obtaining baseline balance measurements with an acclimation trial followed by a baseline session with 2 baseline tests. Prospective studies are required for validation.

Normative Data Set of SWAY Balance Mobile Assessment in Pediatric Athletes

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AUTHORS: Stevi L. Anderson, MS, Dustin Gatens, MS, Colette Glatts, MS, and Stephen A. Russo, PhD

METHODS: Baseline assessments completed by certified athletic trainers at an outpatient concussion center or sports medicine offices in Philadelphia, PA and surrounding suburban Pennsylvania and New Jersey or during an athletic trainer’s baseline assessment of collegiate athletes at a National Collegiate Athletic Association (NCAA) Division-II University in Fort Lauderdale, FL. Test results of a sample of 466 athletes aged 5 to 18 years were included. The SWAY Balance test was administered using a mobile device on all participants as part of a standard preseason, baseline evaluation, following the standard evaluation protocol. Baseline SWAY Balance mobile assessment balance and reaction time scores, age and sex effects, were examined.

RESULTS: Normative scores are described, with results stratified into 4 age groups (5-9, 10-12, 13-17, and 18 years old). Balance scores, overall and within each individual stance score, improved with the age of the participants. Sex effects on balance were only seen in single-leg stances, with females outperforming males. Reaction time was found to be faster in males and improved with age, peaking at 13 to 17 years old and slowing in 18-year-olds.

CONCLUSION: Normative, age-specific SWAY Balance test results provided are of clinical use as references in the concussion assessments of pediatric athletes.

Balance Performance in Collegiate Athletes: A Comparison of Balance Error Scoring System Measures

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AUTHORS: Nicole C. Dabbs, Nicole M. Sauls, Alice Zayer and Harish Chander

METHODS: One hundred and eighty-four Division-II male and female athletes (age 20.07 ± 1.67 years, height 175.54 ± 11.94 cm, weight 75.24 ± 14.20 kg) volunteered to complete a single testing session. Balance measures were assessed with Sway Medical’s Concussion Management System Application (Sway Medical, Tulsa, OK, USA, version used) an application software that uses tri-axial accelerometers within the iOS mobile device to calculate postural sway during BESS. All participants completed one testing session that included a familiarization and a testing condition for BESS test, using both the BBS and SMBA devices simultaneously. Pearson’s r correlations were used to determine the relationship between the BBS and SMBA during each of the five conditions and an overall score. Correlational strengths were based on the
during each of the five conditions and an overall score.

RESULTS: There were significant, moderate, and negative correlations for DL (p < 0.001, r = −0.32, R2 = 0.10) J. Funct. Morphol. Kinesiol. 2017, 2, 26 2 4 of 7 and TL (p ≤ 0.001, r = −0.32, R = 0.10). There was no significant correlation (p = 0.08, r = −0.13, R2 = 0.01) for TR. There were significant, high, and negative correlations for SLR (p < 0.001, r = −0.64, conditions showed a significant, high, and negative correlation (p < 0.001, r = −0.70, R2 = 0.50) (Figure R2 = 0.41) and SLL (p ≤ 0.001, r = −0.70, R2 = 0.50). The overall score incorporating all five. The SMBA was also validated through the analysis of z-scores showing no significant (p = 1.0) stance conditions showed a significant, high, and negative correlation (p < 0.001, r = −0.70, R2 = 0.50) statistical differences for all five stance conditions and the overall score between the two systems. The SMBA was also validated through the analysis of z-scores showing no significant (p = 1.0) statistical differences for all five stance conditions and the overall score between the two systems.

CONCLUSION: In today’s society, electronic devices are widely used, and the SMBA is easily accessible, simple to administer in any setting, and an affordable tool for balance and postural stability assessments, especially using the BESS protocol. The results from the study demonstrate that the SMBA could be used as a valid measure during BESS in healthy collegiate Division-II athletes.

Correlation Between Scores on the Modified CTSIB When Using the SWAY and NeuroCom VSR Sport

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AUTHORS: Foster Mackenzie P., Johnson Victoria L., Kegg Ryan J., McDowell Claudia A., Mercer Morgan L., Sponsler Britany L., Sta

BACKGROUND: Data collected from gyroscopes and accelerometers as well as force plates have been found to have a strong correlation according to various research studies. (cite). The Modified Clinical Test of Sensory Interaction and Balance (mCTSIB) is a tool commonly used to assess postural sway with a focus on sensory contributions. Few studies are available directly comparing the “score” data collected by specific systems.

METHODS: All testing was done on-site at SFU. A consent form was provided to subjects. Subjects were given instruction once and then performed the mCTSIB accord-ing to the specific protocol of each device, with participants alternating which test was performed first. Subjects completed the mCTSIB two times in total. The iPad and harness was worn during both trials. Data was recorded and an-alyzed for any correlation. During pilot testing, it was revealed that due to the protocols on the software, the timing of the tests would not match up correctly for data collection. (SWAY 30 sec, VSR Sport 3, 10 sec increments) Four trials were completed for each device: Eyes open firm surface, eyes closed firm surface, eyes open foam surface, eyes closed foam surface

CONCLUSION: Moderate inverse correlation was found between scores during the following trials: Eyes closed on firm surface (p = 0.0011), Eyes closed on foam surface (p = 0.0006), Composite score of all four trials (p = 0.0008). The SWAY Balance System may be an effective and viable tool for balance as-sessment. Further research is needed using different SWAY Balance System protocols to determine if it is a reasonable alternative for use with concussed individuals.

The Relationship Between Sway Balance and Self-Reported Symptoms Following a Sports-Related Concussion

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AUTHORS: Tiffany McGuffin, MS, ATC; Stephanie M. Turner, MS; Tami Case, PA-C; Damond Blueitt, MD; J. Craig Garrison, PhD, PT, ATC, SCS; Kalyssa Creed MS, CCRP; Angela C. Baleztena, MS, ATC; Anthony J. Anzalone, MS; Jonathan M. Oliver

BACKGROUND: Following a sports-related concussion, patients often exhibit deficits in postural stability and reaction time (RT). The Sway BalanceTM System (SWAY) is an FDA-approved mobile application that has proven to reliably and objectively assess both balance and RT. The post-concussion symptom scale (PCSS) asks patients to self- report their symptoms following a concussive injury. The relationship between self-reported symptoms of concussion and the SWAY protocol has not been examined.

METHODS: 67 pediatric athletes who sustained a sports-related concussion were included in the study. All participants completed the PCSS and SWAY within 14 days of injury during their first visit to a pediatric sports-concussion clinic. The SWAY system calculates balances scores from 0 to 100 (0 = completely unstable, 100 = completely stable) for each of the following: bipedal stance (feet together), tandem stance (R foot forward), tandem stance (L foot forward), single leg stance (R), single leg stance (L). RT scores include: motion reaction time (MRT) score, and MRT (milliseconds). The self-reported PCSS symptoms of balance difficulties and feeling slowed down, were used to determine whether or not the perception of symptoms associated with poor balance and decreased reaction time were related to SWAY scores.

RESULTS: Pearson product-moment correlations were utilized to examine the relationship between SWAY scores and the PCSS balance difficulties and feeling slowed down scores. The self-reported feeling slowed down score was not related to any of the SWAY scores, but the self-reported balance score was positively correlated to single leg (R) score (r = 0.246; p = 0.043).

CONCLUSION: These data suggest that subjective assessments of balance and RT via the PCSS may not be linked to SWAY scores. Patients may not be able to sensitively detect or perceive difficulties (or lack thereof) with postural stability or RT following a sports- related concussion. Further study is warranted using additional objective measures of balance and RT to determine if patients suffering from sports-related concussion are consistently inaccurate in perceiving such deficits. Baseline balance and RT scores may be more useful for detection of postural instability or RT deficits following a concussion than reliance on subjective measures of balance and RT as patients likely cannot accurately discern whether or not balance or RT deficits are present following injury.

Validity of using smart phone sway balance application in measuring dynamic balance

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AUTHORS: Mohamed M. Eldesoky, Neveen A. Abd-Elraouf, Khaled E. Ayad, Enas E. Abu-Taleb.

METHODS: The study protocol, aim and importance were explained to all the participants. A written agreement form was signed by each participant. All the participants caught the iphone device containing the SBS in the upright position with the screen facing their mid of sternum and pressed it against their sternum while performed four tests (foot together, semi tandem, tandem and single leg stance) all done with eyes opened while the participant standing on the platform of the BBS (performing the test on BBS and the SBS at the same time as it is concurrent validity test) fig.1, 2, 3&4. The dominant leg was the leg in front in both tandem and semi tandem positions and the leg of weight bearing in the single leg stance position. Each test was done for 10 seconds and all participants performed experimental trials on level 8 Biodex Balance System difficulty with a familiarization trail prior to it. The overall stability index for each test was collected from experimental trial of each participant on both BBS and the same the overall postural sway was collected from SBS for each test and statistically analyzed.

RESULTS: Thirty healthy subjects participated in this study. Data obtained from the study group regarding overall posture sway of smart phone sway balance application were correlated with overall stability index of biodex balance system at stability level 8 under four conditions; foot together, semi tandem, tandem and single leg stance. The correlations between overall posture sway and overall stability index at level 8 were moderate negative significant correlation at foot together (r = -0.42, p = 0.02), moderate negative no significant correlation at foot semi tandem (r = -0.35, p = 0.053), strong negative significant correlation at foot tandem (r = -0.8, p = 0.0001), and moderate negative significant correlations at single leg stance (r = – 0.61, p = 0.0001).

CONCLUSION: Using of smart phone Sway Balance application in measuring the dynamic balance is valid as well as the static balance as it was compared with the laboratory gold standard Biodex Balance System which is proved to be valid in measuring dynamic balance. This is a very important result as it providing an easy using, portable, cost effective and objective method to evaluate the dynamic balance in any field. So, it is recommended to the physical therapists to use the SBS in testing and reevaluation of the dynamic balance and at any field.

Test-Retest Reliability of the Sway Balance Mobile Application

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AUTHORS: Ryan Z. Amick, PhD, Alex Chaparro, PhD, Jeremy A. Patterson, PhD, Michael J. Jorgensen, PhD

BACKGROUND: The SWAY Balance Mobile Application is an FDA-cleared balance testing system which uses the built-in tri-axial accelerometers of a mobile electronic device to objectively assess postural movement. The system was designed to provide a means of quantitative balance assessment in clinical and on-field environments. The purpose of this study was to determine the intrasession and intersession reliability, as well as the minimum difference to be considered real, of the SWAY Balance Mobile Application.

METHODS: 24 individuals (15 male, 9 female; aged 25.96 (95.78 years)) performed the SWAY Balance protocol twice per testing session over a period of three testing sessions. Each testing session was separated by a minimum of seven days. Interclass Correlation Coefficients were calculated as an indication of the test-retest reliability. The minimum difference to be considered real was calculated to determine the minimum score change necessary to indicate an actual change in balance performance.

RESULTS: Mean SWAY Balance scores ranged from 86.90 (914.37) to 89.90 (911.19). Repeated measures ANOVA revealed no significant mean differences between SWAY balance scores of the experimental trials (F(5,115) 0.673; p 0.65). Excellent reliability was found (ICC(3,1) 0.76; SEM 5.39) with a minimum difference to be considered real of approximately 15.

CONCLUSION: Results indicate that SWAY provides excellent overall reliability. However, it may be appropriate to have subjects perform a familiarization trial at the beginning of each testing session. Additionally, SWAY may demonstrate a ceiling effect when assessing balance improvements in those who already demonstrate good balance.

Concussion Screening Evaluation: BESS vs. SWAY

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AUTHORS: Jeremy Altman, Linda Ye, Zach Hatoum, Aurash Zarrinbakhsh, Aidan Neustadtl, Dave Milzman, MD

OBJECTIVE: The Balance Error Scoring System (BESS) is the current gold standard for evaluating balance, one of the best predictors for the need for concussion intervention. Sway, a new gyroscope based iPhone application, is being proposed as a more sensitive and objective test. Our study compares Sway to BESS to determine if there is equal efficacy.

RESULTS: There is a moderate to strong correlation between BESS and Sway scores. The results are significant (p<.001). The average score of 4.1 on BESS correlates to an average score of 77.1 on Sway. According to “Normative data for the balance error scoring system: Implications for brain injury evaluation” (G.L. Iverson, M.L. Kaarto, and M.S. Koehle), the 76-90th percentile of individuals ages 20-39 scored 4-6 on BESS.

CONCLUSION: Sway is equally, if not more, sensitive as BESS. Sway leaves little room for human error. Future studies can determine if use of this simple accurate test will improve diagnosis of G concussion in the ED.

Using Sway as an Objective Assessment for Sports Related Concussion Balance Testing in High School and College Athletes

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AUTHORS: Thomas M. Mullin, MD, Nicholas R. Phillips, MD, Corina Martinez, PT, Claude T. Moorman III, MD, Jeffrey R. Bytomski, DO, FirstLight Health System, Samaritan Athletic Medicine

OBJECTIVE: Balance assessment is an important component of concussion assessment. We compared an objective measure of balance using the SWAY Balance application for the Apple iPhone to the balance error scoring system (BESS) in non-concussed high school and collegiate athletes.

RESULTS: Across age and gender, there was an inverse relationship between overall SWAY and the global BESS score (r= –0.402, P<0.001), the BESS firm score (r= –0.34, P=0.004) and the BESS foam score (r= –0.27, P=0.024). For high school age subjects, there was an inverse relationship between the SWAY score and the global BESS score (r= −0.33, P=0.017) and for BESS Firm (r= −0.35, P=0.01). For the college age subjects (all were male), there was an inverse relationship between the SWAY score and the global BESS score (r= −0.52, P=0.032).

CONCLUSION: There is a significant inverse relationship between BESS testing and SWAY balance testing in non-concussed high school and collegiate athletes. Use of a smart phone with software utilizing the accelerometer may one day provide an objective tool for the assessment of balance in sport-related concussion.

Validity and Reliability of Mobile Postural Stability Testing Devices for use in Clinical Concussion Assessment

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AUTHORS: Haley C. Seymour, Nicole B. Brashears, Kho T. Roberts, Stephanie A. Mock, Michelle A. Cleary PhD, ATC, CSCS, Tricia M. Kasamatsu PhD, ATC

OBJECTIVE: The purpose of our study was to: 1. Explore the reliability of mobile postural stability tests including a pressure-sensing platform (MobileMat®, Tekscan, Inc., Boston, MA), and a mobile smartphone/tablet application (SwayBalance®, SwayMedical LLC, Tulsa, OK). 2. Establish validity of the mobile postural stability tests in comparison to the laboratory gold-standard forceplate device (a forceplate device, BioSway®, Biodex Stability System, Shirley, NY), as well as the common clinically used modified Balance Error Scoring System. The research questions that guided this investigation were as follows: 1. Are ATs using reliable tools for assessing concussion in sport? 2. How do new mobile postural stability tests compare to the gold-standard device?

CONCLUSION: All the devices were found to have moderate to excellent intra-device reliability; however, scores generated by these tests did not significantly correlate with the gold standard forceplate device. Clinicians should use caution when interpreting data from these mobile postural stability tests. If these tests are used in the clinical setting, baseline testing should utilize the same test that will be used post-injury. Based on our findings, we have arrived at the following conclusions: 1. All of the tested mobile postural stability testing devices are reliable within themselves. The postural stability tests have not been demonstrated to be valid compared to each other. Clinicians should use caution when changing between postural stability tests. Ideally a clinician will choose one test to implement in their setting and complete both baseline and post-injury testing with the same device. Due to the lack of validity when comparing the individual tests to one another, results from one test cannot and should not be transferred from device to device.

Comparison of BESS, Biodex Balance System SD, and Sway Balance App

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AUTHORS: Kevin M. Swartz, ATC; Jordan T. Eshbaugh, ACT; Schott L. Bruce, EdD, ATC

BACKGROUND: A correlation study comparing SBA to BESS has been done, but not for comparing SBA to BBS. Pearson r for SBA to BESS (r = – 0.787, p < 0.01). No correlational studies comparing BESS to BBS were found in the literature. A pair of concurrent validity studies comparing SBA to BBS have been done, but no validity studies for SBA & BESS. No statistical difference between the SBA & BBS devices on a firm surface ( p > 0.05) indicating validity. Statistical difference found standing on a foam surface (p < 0.05). No statistical difference using a single leg stance among SBA & BBS devices ( p = 0.818) 4 indicating validity. The purpose of our study was to determine if a relationship exists between BESS, BBS, and SBA.

METHODS: Groups of 3 subjects were assessed simultaneously, randomly assigned the order for each balance platform. The BBS and SBA were scored by each unit, measuring the subject’s postural sway. Each unit graded on a different numerical scale: BBS scale 0 (perfect balance) to 4 (poor balance), SBA scale 100 (perfect balance to 0 (no balance), The BESS was scored by the number of errors the subject committed while in the specified stances. Balance scores were then converted to z-score for standardization & correlations were run with like stances.

RESULTS: There were no significant correlations between any of the three balance assessment tools. Pearson r correlation statistics were run on the balance assessment tools. There were no statistically significant results found with these subjects, in these circumstances

Sideline Screening for Balance and Neurocognition. There’s an App for That…

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AUTHORS: Mark Burghart MOT, OTR/L, Jordan Taylor M.Ed., CSCS, and Jeff Radel PhD

BACKGROUND: Symptoms of concussion can be subtle, have variable onset, and can be difficult to measure. Identifying a concussion accurately is critical for preventing subsequent brain injuries, particularly in youth sports. Current tests of neural function are not practical or objective when used in practice/play settings.

METHODS: Obtain informed consent & demographic data: 22 members of the KC Spartans full-contact women’s football team – 30 ±5.5 years old, 15 ±1.7 years education, 28.4 ±4.8 BMI, 41% of subjects reported prior head injuries (9 of 22), 27% reported more than one head injury (6 of 22), 14% have been diagnosed with concussion (3 of 22), SCAT2 test (20 min) given by trained administrator, Concussion Manager testing (5-7 min) with iPod Touch • Test results compared to determine extent of agreement between SCAT2 and CM app measures, Bland-Altman2 analysis determines “agreement” of scores across tests, irrespective of differing measurement scales; is more robust than tests of variance or correlation when test format is a consideration.

CONCLUSION: Concussion Manager app is a viable alternative to the SCAT2 in screening for concussion symptoms: High agreement of CM app & SCAT2 test results, Objective (CM app) vs. subjective (SCAT2) balance tests, CM app includes reaction time measures, automatic data recording, and on-line access to current & prior test results, Supports evidence-based education through hands-on involvement of stakeholders (athletes, coaches).

Reliability and Responsiveness of a Mobile Device Application for Measurement of Postural Sway in People with Parkinson Disease

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AUTHORS: Connie Fiems MPT, DHSc, NCS; Elizabeth S. Moore1 PhD; Eric L. Dugan PhD; Stephanie A. Combs-Miller1 PT, PhD, NCS

OBJECTIVE: To determine the test-retest reliability and responsiveness of the SWAY BalanceTM application (SWAY) for measuring postural sway under varied static standing conditions in individuals with Parkinson disease (PD) across Hoehn & Yahr levels (H&Y) 1-3.

CONCLUSION: Our results indicate both SWAY protocols demonstrate high to fair test-retest reliability in individuals with PD. The mCTSIB achieved high reliability that may ensure clinical validity. Further study with a larger, more heterogeneous sample is required to determine responsiveness with SEM and MDC, as well as normative values for this population. Because many participants were not able to maintain test positions, issues concerning measurement error and protocol difficulty should be explored.

The Relationship Between Sway Assessment, Dizziness Handicap Inventory and Videonystagmography Tests in Dizzy Patients

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AUTHORS: Kristine Sonstrom MS, Jennifer Franson-Hopper AuD, and Elias Michaelides MD, Yale Hearing and Balance Center, Department of Otolaryngology, School of Medicine, New Haven, CT

INTRODUCTION: The evolution of smartphone technology has provided patients with an ability to self evaluate and quantify their physical symptoms prior to an evaluation by a medical professional. Modern mobile devices employ accelerometers which function to measure postural sway. The introduction of a new technology, SWAY BalanceTM, operates through a software platform utilizing a tri-axial accelerometer measuring postural sway. To our knowledge, this technology has not been utilized in patients with vestibular related disorders. Two current assessments used to evaluate patient dizziness include Videonystagmography (VNG) and the Dizziness Handicap Inventory (DHI). Presently used force platforms can be challenging due to equipment cost, size, mobility, accessibility, duration of use and need for specialized personnel. SWAY BalanceTM provides an attractive means of screening dizzy patients for quantitative information associated with their dizziness and balance.

CONCLUSION: The SWAY BalanceTM mobile application provides a convenient and attractive means of obtaining quantitative information on dizzy patients by measuring postural sway while isolating each component of the balance system. Our findings suggest there is no significant relationship between the VNG, DHI and SWAYTM Balance Assessment and no significant difference between test subjects and controls on the fall and mBESS assessment. Our results demonstrated the ceiling effect among different portions of the SWAYTM fall assessment and no significant differences between our test subjects and controls. It is suggested that modifications to the SWAYTM Balance protocol specific for those with vestibular related disorders could make the test more sensitive to asymptomatic and symptomatic dizzy patients. Although this pilot study did not indicate a significant relationship between these three measures, further research is warranted under specific conditions modified for those patients with vestibular related disorders.

Comparison of Postural Sway Using a Balance Platform and Mobile App

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AUTHORS: Nobuo Takeshima, Jeremy A. Patterson, FACSM, Ryan Z. Amick, Nicole L. Rogers, Kaelin C. Young, Michael E. Rogers, FACSM Wichita State University, Wichita, Kansas, USA

OBJECTIVE: Balance training has become common in therapeutic exercise routines for rehabilitation, injury prevention, and fall prevention. Unstable surfaces such as foam pads are commonly used in these purportedly to improve balance. While postural sway is often used as a measure of balance ability and to evaluate the efficacy of such programs to improve postural balance, there is little research regarding the measurement of sway while standing on foam pads. Purpose: To compare measures of postural sway from a clinical balance platform against a mobile application.

CONCLUSION: The mobile application is a valid and useful clinical tool for the evaluation of balance as results did not differ with the balance platform when measuring balance on the stable surface.
Given that postural sway did not differ between unilateral stance on firm versus foam surfaces with the balance platform, it appears that the balance platform does not effectively measure sway while standing on foam. Therefore, this mobile application may be a better tool for quantification of sway while standing on foam.

Comparison of a Mobile Technology Application with the Balance Error Scoring System

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AUTHORS:  Patterson, Jeremy A., Amick, Ryan Z., Pandya, Priyanka D., Hankansson, Nils, and Jorgensen, Michael J.

ABSTRACT:  The most widely used method for postural balance assessment relies on the subjective observations of a test administrator. Accelerometry has been shown to provide a valid and reliable method for assessment of balance, and recent advances in microelectromechanical systems have made the technology available in mobile electronic devices.

PURPOSE:  To compare a mobile technology application with a commonly used subjective balance assessment.

METHODS: Twenty-one nonathlete col- lege-aged individuals (7 men, 14 women; mean age 23 ± 3 years) volunteered to participate. Subjects were excluded if they reported any preexisting condition that might affect postural balance.

RESULTS:  A strong inverse correlation was found between the scores for the two balance assessment methods (= -.767, < .01).

CONCLUSION:  Advances in technology have provided an attractive means to objectively quantify postural balance with off-the-shelf mobile consumer electronic devices.

Validation of Measures from the Smartphone Sway Balance Application: A Pilot Study

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AUTHOR: Jeremy A. Patterson, PhD, FACSM

BACKGROUND: A number of different balance assessment techniques are currently available and widely used. These include both subjective and objective assessments. The ability to provide quantitative measures of balance and posture is the benefit of objective tools, however these instruments are not generally utilized outside of research laboratory settings due to cost, complexity of operation, size, duration of assessment, and general prac- ticality. The purpose of this pilot study was to assess the value and validity of using software developed to access the iPod and iPhone accelerometers output and translate that to the measurement of human balance.

METHODS: Thirty healthy college-aged individuals (13 male, 17 female; age = 26.1 ± 8.5 years) volunteered. Participants performed a static Athlete’s Single Leg Test protocol for 10 sec, on a Biodex Balance System SD while concurrently utilizing a mobile device with balance software. Anterior/posterior stability was recorded using both devices, described as the displacement in degrees from level, and was termed the “balance score.”

RESULTS: There were no significant differences between the two reported balance scores (p = 0.818. Mean bal- ance score on the balance platform was 1.41 ± 0.90, as compared to 1.38 ± 0.72 using the mobile device.

CONCLUSION: There is a need for a valid, convenient, and cost-effective tool to objectively measure balance. Results of this study are promising, as balance score derived from the Smartphone accelerometers were consist- ent with balance scores obtained from a previously validated balance system. However, further investigation is necessary as this version of the mobile software only assessed balance in the anterior/posterior direction. Addi- tionally, further testing is necessary on a healthy populations and as well as those with impairment of the motor control system.

LEVEL OF EVIDENCE: Level 2b (Observational study of validity)

Mobile Reaction Time

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WHAT IS REACTION TIME: Reaction time is a measure of sensory and neuromotor function that encompasses stimulus recognition and processing followed by the initiation of a neuromotor response. Reaction time can be tested with varying levels of difficulty in the sensory phase, or the neuromotor response phase. The Simple Reaction Time (SRT) test is the most elementary form of reaction time measurement, which looks at signal processing of a single stimulus with a defined physical response, such as pressing a button.

MEASURING REACTION TIME: Reaction time is typically evaluated digitally with a computer program, measuring the time lapse between stimulus presentation on the screen and the touch of a keyboard or click of a mouse. More practical and accessible tools for reaction time assessment have been suggested1, however these tools are typically not digitally connected for archiving individualized comparative measurements and require equipment that is not always available outside of the clinic. Computerized testing is generally accepted as the gold standard for reaction time assessment despite mouse and keyboard latency variations of 20 to 50 milliseconds2,3 between commercially available models. The main practical limitation of computerized testing is the immobility of the testing platform. Recent efforts to promote cognitive assessment on mobile devices have attempted to address the portability issue in computerized testing with the use of touch screen devices. A transition to touch screen reaction time assessment has been slowed due to latency in the touch identification mechanisms of mobile devices. Recent studies have failed to produce statistical equivalence between touch-based reaction time assessment and computerized testing.

Comparison of the SWAY Balance Mobile Application to the BESS Balance Assessment in Older Adults

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AUTHORS: Samantha D. Jansen, Ryan Z. Amick, Danielle C. Stern, and Jeremy A. Patterson, FACSM

ABSTRACT: Balance assessment has commonly been subjective; however, advances in handheld mobile devices have provided objective balance measurement tools. Recently, the SWAY Balance Mobile Application, which utilizes tri-axial accelerometers to determine balance variations, was significantly correlated with the Balance Error Scoring System (BESS) for young adults. Older adults have not been assessed.

PURPOSE: Compare the objective SWAY to the subjective BESS balance assessment for older adults.

METHODS: Forty-three older adults (19 male; aged 60.14 + 6.72 years) completed the SWAY and the BESS concurrently. A lower score on the BESS indicates better balance, whereas, a higher score on the SWAY indicates better balance. Correlation analyses were used to determine the relationship between the SWAY and the BESS.

RESULTS: There was a significant negative correlation between the SWAY scores and the BESS scores (r = -0.640, p < .01).

CONCLUSION: SWAY may provide an objective way to assess balance of older adults.

Association Between Balance and Lower Extremity Strength in Older Adults Aged 50 to 74

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AUTHORS: Caitlin D. Stover, Ryan Z. Amick, David E. Geddam, Kaelin C. Young, Jeremy A. Patterson, FACSM

ABSTRACT: The ability to reduce functional limitations in older adults is a significant public health concern. With increasing age, many functional abilities can decrease secondary to physiological changes, limiting the ability to perform activities of daily living. Improved balance and lower extremity strength have been shown to be associated with reduced functional limitations in older adults. Additionally, improved lower extremity strength has been shown to improve balance in older adults.

PURPOSE: The purpose of this study was to determine the association between lower extremity strength and balance as measured with a new balance assessment technique.

METHODS: 48 independent living older adults (21 male, 27 female; 59.7 (6.7) yrs) free of conditions known to affect balance, completed the SWAY balance assessment. The assessment utilizes a software application which accesses the accelerometer in a commonly available mobile consumer electronics device. For the balance assessment, the device is held against the chest at mid-sternum level. The assessment consists of 5 balance stances including feet together, tandem right foot front, tandem left foot front, single leg stance (SLS) right and SLS left. Each stance is assessed for 20 seconds. Upon completion of all balance stances, a balance score was generated. Lower extremity strength was then assessed by maximum voluntary contraction (MVC) with an isokinetic dynamometer for knee flexion (MVC-fl x) and extension (MVC-ext).

RESULTS: Mean MVC were 78.2 (26.3) Nm and 160.0 (61.8) Nm for MVC-flx and MVC-ext respectively. Mean SWAY score was 66.1 (16.6). A significant negative correlation was found between both the SWAY balance score and MVC-fl x (r= -0.289, p<0.05) and MVC-ext (r= -0.295, p<0.05). However, after controlling for age and sex, balance and strength associations were no longer significant (p>0.05). Age was the only observed significant independent variable within the regression model (r= -0.442, p<0.01).

CONCLUSION: The negative correlation found between SWAY and lower extremity strength may result from the SWAY Balance Mobile Application measuring balance differently than traditional methods. Additionally, the negative correlation between balance scores and age may indicate that age is the predominant factor in reduced balance observed in older adults irrespective of lower extremity strength.

Balance Assessment Using the Balance Error Scoring System: 10 Seconds versus 20 Seconds Evaluation Time

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AUTHORS: Ryan Z. Amick, Danielle C. Stern, Samantha D. Jansen, and Jeremy A. Patterson, FACSM

ABSTRACT: The Balance Error Scoring System (BESS) is a subjective clinical balance assessment frequently used by various healthcare providers. A test administrator records the number of pre-defined errors committed by the test subject as they perform a number of balance stances.

PURPOSE: The purpose of this study was to determine if there is a difference in the number of observed errors between the 1st and 2nd 10 second time intervals of the assessment.

METHODS: 44 subjects (19.6 + 1.2 yrs) performed a familiarization trial immediately followed by an experimental trial. All trials were scored by a Certified Athletic Trainer.

RESULTS: BESS errors during the 1st and 2nd 10 second time intervals were 2.8 ± 2.4 and 3.3 ± 2.8 respectively. Paired samples t-test reveals no significant difference between the means.

CONCLUSION: Our results conclude that there is no significant difference in observed errors between the 1st and 2nd 10 second time intervals of BESS. 

BESS Scores Observed in Real Time Versus with Slow-Motion Video Recording

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AUTHORS: Danielle C. Stern, Ryan Z. Amick, Samantha D. Jansen, and Jeremy A. Patterson, FACSM 

ABSTRACT: The Balance Error Scoring System (BESS) is a subjective clinical balance assessment frequently used by various healthcare providers. A test administrator records the number of pre-defined errors committed by the test subject as they perform a number of balance stances.

PURPOSE: The purpose of this study was to determine if there is a difference in the number of observed errors when scoring the BESS in real time versus watching a slow-motion video recording.

METHODS: 43 subjects (60.0 + 6.76 yrs) performed a familiarization trial immediately followed by an experimental trial. All trials were recorded on video and BESS scoring was completed by a Certified Athletic Trainer.

RESULTS: Total BESS scores evaluated in real time and evaluated with slow-motion video were 11.07 ± 4.10 and 11.23 ± 4.77 respectively. Paired samples t-test reveals no significant difference between the means.

CONCLUSION: Our results conclude that there is no significant difference in observed errors when scoring BESS in real time vs. slow motion video.

Assessing Balance in High School Athletes and Its Role in Concussion Management

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AUTHORS: Staab, Carina A.

ABSTRACT: Technological advancements in electronics have provided access to quantitative methods of measuring balance or postural stability. In the past decade mobile devices have added built-in motion sensors called tri-axial accelerometers. Developers are accessing the accelerometer outputs while the device is against the body, and translating the values to postural sway and/or stability.

PURPOSE: The purpose of this study was to assess balance in high school athletes using a mobile device software application using accelerometric motion sensors in order to provide information for concussion management and return-to-play.

METHODS: 121 healthy high school-aged athletes (62 male, 59 female; average age = 16.1 plus/minus 1.3 yr) performed a series of balance tasks (bilateral, tandem, single leg) over multiple visits. Age, sex, orthopedic injuries post concussions, height, and weight were also recorded.

RESULTS: Balance scores for concussed athletes did not show any significant difference between baseline and post-concussion test; however, there were three large effect size and one moderate effect size calculated. No significant differences were observed in balance scores between ages.

CONCLUSION: Balance or postural sway is one of many important factors in providing vital information to help medical professionals determine proper management and return-to-play. Mobile devices with tri axis accelerometers is a new innovative and cost-effective method to measure human balance, however, more research needs to be completed to assess its effectiveness in identifying potential impairments resulting from sports concussions or mild traumatic brain injury.

Validation of Balance Assessment Measures of an Accelerometric Mobile Device Application Versus a Balance Platform

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AUTHORS: Rohleder, Peter Alexander

ABSTRACT: Recent technological advancements in electronics and telecommunications have provided more accessible quantitative methods of assessing balance. The latest smartphones have built-in motion sensors called tri-axial accelerometers, which are an ideal choice for evaluating variability of movement and balance providing a non-invasive, portable method of measurement.

PURPOSE: The purpose of this study was to compare the balance assessment measures from a mobile device application (iPod) utilizing accelerometric motion sensors against the balance assessment measures of a clinically valid and reliable balance platform (BIODEX Balance System SD).

METHODS: 75 healthy college-aged individuals (37 male, 38 female; average age = 24.2±6.8 yr) performed a series of balance tasks over two visits (Study 1 and Study 2). During Study 1, 8 balance tests were assessed, beginning with two feet on ground (baseline) and progressively becoming more difficult and repeating them over three trials. iPod Touches with a software application to measure balance was used to assess sway. During Study 2, participants completed 4 balance assessments using a clinically validated balance platform and the iPod Touches, at the same time.

RESULTS: Data showed that the iPod Touches were consistent with expect outcomes, based off of normative data; the more unstable the assessment the higher the balance score compared to baseline or standing with feet together eyes open without foam. Analyses of the 3 trials suggest that a familiarization test should be performed when using the iPod Touch balance application and this is consistent with other devices. Results from Study 2 showed no significant difference between the two devices when measuring without foam, but a significant difference was found between the two while balancing on foam.

CONCLUSION: Balance scores measured by accelerometers within an iPod appear to be a valid and consistent method of measuring human balance.

Assessment of Balance and Cognitive Function in Youth Gymnasts

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AUTHORS: Epps, Elizabeth J.; Staab, Carina A.

ABSTRACT: International recruitment of female gymnast identifies children from the age of 4 years old. This study focuses on measuring components of gymnastics, using validated equipment to assess balance, reaction time, and working memory of level 4-5 gymnasts. 16 competitive female gymnasts (6-13 year-olds) were recruited. Single leg and Tandem Balance Test measured sway and stability while holding an iPod. Reaction time and memory was measured through a sequence of screens asking the subject to touch a point on the iPod as fast as possible and memorize a list of words, then tested recall of the word list. Results suggested no significance between trials 1, 2, and 3 on balance, reaction time and working memory.

CONCLUSION: Gymnastics requires balance, focus, and quick response. Gymnasts of different ages and cognitive abilities perform at different skill levels. This study provides valuable data for the gymnast and the coach on the strengths and weaknesses of each gymnast. Balance is frequently performed on one leg in the gymnast’s floor routine as well as on the balance beam; transference of muscle memory patterns from both events could be a factor in the balance performance during testing. Single leg balance stance scored lower demonstrating less sway of the gymnasts than tandem stance. This is an example of transfer of training of single leg balance stance on the balance beam and floor. Age could present an assumption of better balance, quicker reaction time [3] and cognitive function. A study with gymnasts involving balance, reaction time, and working memory should involve a larger group of gymnasts with varying levels of skill. Our data was skewed by two high scores for balance in trial 2 by two different gymnasts. The standard deviation in the second trial was tripled from the first trial, possibly due to distraction from the testing environment. The gymnast’s demonstrated an increase in working memory over the three trials, shown through a decrease in standard deviation for each trial. A larger group of gymnasts would allow those two girls to be excluded from the study, allowing for more reliability in the statistical analysis. Future studies will include a larger group of gymnasts and will set parameters that control such factors as, the number of participants in the testing environment.

Reproducibility of Balance Measures Using Motion Sensors in Smartphone Technology to Measure Balance: Preliminary Result.

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AUTHORS: Staab, Carina A.; Amick, Ryan Zackary; Epps, Elizabeth J.; Thummar, Tarunkumar

PURPOSE: This pilot study was to determine the reproducibility of the output generated by Smartphone accelerometers when used for balance assessment.

METHODS: 61 healthy individuals (28 male, 33 female; mean age = 23.8+6.2yr) performed a static Single Leg Athlete’s Test (SLS) and a Tandem Stand with eyes closed (TSEC) for 10 seconds each. A commercially available Smartphone was used to determine Anterior/Posterior stability. 4 trials were completed for each test with 1 minute rest between trials.

RESULTS: For each balance assessment, one-way ANOVA was performed and pairwise comparisons determined. For SLS, no significant differences were noted between trials (p = 0.05). For TSEC, trial 1 was significantly different from trials 2, 3, and 4 (p < 0.05). Additionally, for TSEC, a significant difference was observed between trials 2 and 4 (p < 0.05), however neither trial 2 nor 4 was significantly different than trial 3. For SLS, no significant differences were observed between trials 2, 3, or 4.

CONCLUSION: No significant differences were found between trials for SLS, the first trial of TSEC was found to be significantly different than subsequent trials. This may indicate a familiarization trial is necessary if Smartphone technology is to be used for conducting balance assessments.

National Athletic Trainers’ Association Position Statement: Management of Sport Concussion

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AUTHORS: Steven P. Broglio, PhD, ATC; Robert C. Cantu, MD; Gerard A. Gioia, PhD; Kevin M. Guskiewicz, PhD, ATC, FNATA, FACSM; Jeffrey Kutcher, MD; Michael Palm, MBA, ATC; Tamara C. Valovich McLeod, PhD, ATC, FNATA

MOTOR CONTROL: The assessment of 1 or more motor-control systems can provide useful information for concussion diagnosis and management. Perhaps the most common concussion-assessment tool is the evaluation of postural control. Overall balance deficits after injury have been attributed to failure to integrate sensory information arising from the vestibular and visual components of the balance mechanism.

NEUROCOGNITIVE TESTING: Neurocognitive testing has historically been viewed as the cornerstone of the concussion-assessment process, yet when used in isolation, this technique does not provide clinically adequate sensitivity to concussion. Therefore, neurocognitive testing should never be used in isolation but rather in conjunction with symptom and motor-control assessments to support the clinical examination.

SELF-REPORT SYMPTOM ASSESSMENT: Collecting subjective symptom information from a patient is a dynamic and complex process. Using symptom checklists (ie, yes/ no) or scales (ie, graded and summed responses) that assess symptom duration or severity (or both) in a standardized manner is recommended. In general, symptom reports provide good sensitivity to concussive injuries.

BASELINE TESTING: The baseline evaluation of an athlete for the purpose of concussion management should include a documented neurologic history with symptoms and physical examination (Table 3). Baseline testing should also involve the objective evaluation of multiple spheres of brain function and, at minimum, assess neurocognitive performance and motor control.