Balance Sway Research Articles

Validity and Responsiveness of a Modified Balance Error Scoring System Assessment Using a Mobile Device Application in Patients Recovering from Ankle Sprain.

Static balance is often impaired in patients after ankle sprains. The ability to identify static balance impairments is dependent on an effective balance assessment tool. The Sway Balance Mobile Application (SWAY App) (Sway Medical, Tulsa, OK) uses a smart phone or tablet to assess postural sway during a modified Balance Error Scoring System (mBESS) assessment and shows promise as an accessible method to quantify changes in static balance after injury. The primary purposes of this study were to determine the ability to differentiate between those with ankle sprain versus controls (construct validity) and ability to detect change over time (responsiveness) of a mBESS assessment using a mobile device application to evaluate static balance after an acute ankle sprain. Case-control study. Twenty-two military academy Cadets with an acute ankle sprain and 20 healthy Cadets were enrolled in the study. All participants completed an assessment measuring self-reported function, ankle dorsiflexion range of motion (via the weightbearing lunge), dynamic balance, and static balance. Static balance measured with the mBESS using the SWAY App was validated against laboratory-based measures. Cadets with ankle sprains completed their assessment twice: once within two weeks of injury (baseline) and again after four weeks of rehabilitation that included balance training. Independent and paired t-tests were utilized to analyze differences over time and between groups. Effect sizes were calculated and relationships explored using Pearson's correlation coefficients. The mBESS scores measured by the SWAY App were lower in participants with acute ankle sprains than healthy Cadets (t = 3.15, p = 0.004). Injured participants improved their mBESS score measured by SWAY at four weeks following their initial assessments (t = 3.31, p = 0.004; Baseline: 74.2 +/- 16.1, 4-weeks: 82.7 +/- 9.5). The mBESS measured by the SWAY App demonstrated moderate to good correlation with a laboratory measure of static balance (r = -0.59, p \< 0.001). The mBESS assessed with a mobile device application is a valid and responsive clinical tool for evaluating static balance. The tool demonstrated construct (known groups) validity detecting balance differences between a healthy and injured group, concurrent validity demonstrating moderate to good correlation with established laboratory measures, and responsiveness to changes in static balance in military Cadets during recovery from an acute ankle sprain. Level 3.

The Convergent Validity of the SWAY Balance Application to Assess Postural Stability in Military Cadets Recovering from Concussion.

Concussions are often accompanied by balance disturbances. Clinically accurate evaluation systems are often expensive, large, and inaccessible to most clinicians. The Sway Balance Mobile Application (SWAY) is an accessible method to quantify balance changes. To determine the known groups and convergent validity of the SWAY to assess balance after a concussion. Case-Control Study. Twenty participants with acute concussion and twenty controls were recruited. At initial, one-week, and final return to activity (RTA) evaluations, all participants completed the Sports Concussion Assessment Tool (SCAT-5), and balance control measured by SWAY mBESS and NeuroCom Balance Master Sensory Organization Test (SOT). Mixed model ANOVAs were used to detect differences in SWAY mBESS and NeuroCom SOT scores with time (initial, one-week, final RTA) as the within-subjects factor and group (concussed, healthy) as the between-subjects factor. Spearman's Rho correlations explored the associations between NeuroCom SOT scores, SWAY scores, SCAT-5 symptom scores, and time in days to final RTA. The sampled population was predominantly male and age (20 ± 1), and BMI differences were insignificant between groups. The SWAY did not detect differences between healthy and concussed participants and did not detect change over time [F(2,40) = .114, p = 0.89; F(2,40)= .276, p =0.60]. When assessing the relationship between the SWAY and the SOT, no correlation was found at any time point (r = -0.317 to -0.062, p > 0.05). Time to RTA demonstrated a moderate correlation with both SCAT-5 symptom severity score (r = .693, p < 0.01) and SCAT-5 total symptom score (r = .611, p < 0.01) at the one-week follow-up. The SWAY mBESS does not appear to be a valid balance assessment for the concussed patient. The SWAY mBESS in patients with concussion failed to demonstrate convergent validity and did not demonstrate an ability to validate known groups. When assessing the time to final RTA, the one-week post-initial assessment SCAT-5 symptom severity and total scores may help determine the length of recovery in this population. Level 3.

Identifying responders to elamipretide in Barth syndrome: Hierarchical clustering for time series data

BackgroundBarth syndrome (BTHS) is a rare genetic disease that is characterized by cardiomyopathy, skeletal myopathy, neutropenia, and growth abnormalities and often leads to death in childhood. Recently, elamipretide has been tested as a potential first disease-modifying drug. This study aimed to identify patients with BTHS who may respond to elamipretide, based on continuous physiological measurements acquired through wearable devices.ResultsData from a randomized, double-blind, placebo-controlled crossover trial of 12 patients with BTHS were used, including physiological time series data measured using a wearable device (heart rate, respiratory rate, activity, and posture) and functional scores. The latter included the 6-minute walk test (6MWT), Patient-Reported Outcomes Measurement Information System (PROMIS) fatigue score, SWAY Balance Mobile Application score (SWAY balance score), BTHS Symptom Assessment (BTHS-SA) Total Fatigue score, muscle strength by handheld dynamometry, 5 times sit-and-stand test (5XSST), and monolysocardiolipin to cardiolipin ratio (MLCL:CL). Groups were created through median split of the functional scores into “highest score” and “lowest score”, and “best response to elamipretide” and “worst response to elamipretide”. Agglomerative hierarchical clustering (AHC) models were implemented to assess whether physiological data could classify patients according to functional status and distinguish non-responders from responders to elamipretide. AHC models clustered patients according to their functional status with accuracies of 60–93%, with the greatest accuracies for 6MWT (93%), PROMIS (87%), and SWAY balance score (80%). Another set of AHC models clustered patients with respect to their response to treatment with elamipretide with perfect accuracy (all 100%).ConclusionsIn this proof-of-concept study, we demonstrated that continuously acquired physiological measurements from wearable devices can be used to predict functional status and response to treatment among patients with BTHS.

Test-Retest reliability and preliminary reliable change estimates for Sway Balance tests administered remotely in community-dwelling adults.

Impaired balance and postural stability can occur with advanced age, following traumatic brain injury, in association with neurological disorders and diseases, and as the result of acute or chronic orthopedic problems. The remote assessment of balance and postural stability could be of value in clinical practice and research. We examined the test-retest reliability and reliable change estimates for Sway Balance Mobile Application tests (Sway Medical, Tulsa OK, USA) administered remotely from the participant's home. Primarily young, healthy community-dwelling adults completed Sway Balance Mobile Application tests remotely on their personal mobile devices once per week for three consecutive weeks while being supervised with a video-based virtual connection. Sway Balance tests include five stances (i.e., feet together, tandem right foot forward, tandem left foot forward, single leg right foot, single leg left foot), which are averaged to compute a Sway Balance composite score from 0 to 100, with higher scores indicating better postural stability. We examined test-retest reliability (measured with intraclass correlation coefficients, ICCs) and preliminary reliable change estimates for 70%, 80%, and 90% confidence intervals. Participants included 55 healthy adults (ages = 26.7 ± 9.9 years, interquartile range = 20-30, range = 18-58; 38 [69%] women). Test-retest reliability for the Sway Balance composite score across three weeks was.88. Test-retest reliability for individual stances ranged from 62 to 83 (all ps < 0.001). At the 80% confidence interval, preliminary reliable changes estimates were 9 points for the Sway Balance composite score. For a remote administration, test-retest reliability was moderate-to-good for all Sway Balance stances, as well as for the Sway Balance composite score. Reliable change estimates may allow clinicians to determine whether an improvement or decline in performance is greater than the expected improvement or decline due to measurement error in young adults.

Effects of a Cognitively Challenging Agility Boot Camp Program on Balance and Gait in People With Parkinson’s Disease: Does Freezing of Gait Status Matter?

Background and Aim: Individuals with Parkinson’s disease (PD) with and without freezing of Gait (FoG) may respond differently to exercise interventions for several reasons, including disease duration. This study aimed to determine whether both people with and without FoG benefit from the Agility Boot Camp with Cognitive Challenges (ABC-C) program. Methods: This secondary analysis of our ABC-C trial included 86 PD subjects: 44 without FoG (PD−FoG) and 42 with FoG (PD + FoG). We collected measures of standing sway balance, anticipatory postural adjustments, postural responses, and a 2-minute walk with and without a cognitive task. Two-way repeated analysis of variance, with disease duration as covariate, was used to investigate the effects of ABC-C program. Effect sizes were calculated using standardized response mean (SRM) for PD−FoG and PD + FoG, separately. Results: The ABC-C program was effective in improving gait performance in both PD−FoG and PD + FoG, even after controlling for disease duration. Specifically, dual-task gait speed (P < .0001), dual-cost stride length (P = .012), and these single-task measures: arm range of motion (P < .0001), toe-off angle (P = .005), gait cycle duration variability (P = .019), trunk coronal range of motion (P = .042), and stance time (P = .046) improved in both PD−FoG and PD + FoG. There was no interaction effect between time (before and after exercise) and group (PD−FoG/PD + FoG) in all 24 objective measures of balance and gait. Dual-task gait speed improved the most in PD + FoG (SRM = 1.01), whereas single-task arm range of motion improved the most in PD−FoG (SRM = 1.01). Conclusion: The ABC-C program was similarly effective in improving gait (and not balance) performance in both PD−FoG and PD + FoG.

A - 27 The Clinical Utilization of SWAY and mBESS for Post-Trauma and Follow-up Concussion Evaluations

Abstract Objective SWAY is a mobile software system using an accelerometer designed to measure postural sway and reaction time in the context of concussion. This study examined the efficacy of SWAY in detecting changes in balance and reaction time before and after concussion. Methods College athletes (N = 30, 10 females) underwent baseline, post-trauma, and follow-up evaluations following a concussion including SWAY, mBESS, Sports Concussion Assessment Tool 5th Edition (SCAT-5), and Immediate Post Concussion Assessment and Cognitive Testing (ImPACT). Results Paired-samples t-tests revealed a decline in SWAY balance from baseline (M = 82.65, SD = 14.48) to post-trauma (M = 74.61, SD = 17.41), t(29) = 2.99, p = 0.006, but no significant difference was observed in reaction time (M = 5.07, SD = 13.61), t(29) = 2.04, p = 0.050. Meanwhile, balance improved at follow-up (M = 78.93, SD = 15.32), and was no longer discrepant from baseline (M = 81.97, SD = 14.51), t(21) = 1.03, p = 0.316. Similarly, there was a significant decline in mBESS scores from baseline (M = 2.88, SD = 3.62) to post-trauma (M = 5.68, SD = 5.32), t(24) = −3.51, p = 0.002, followed by a return to baseline at follow up (M = 4.22, SD = 4.95), t(22) = −1.60, p = 0.124. Conclusions Although challenges were apparent in obtaining an optimal baseline, current results appear to support the clinical utility of SWAY for assessing balance in the context of concussion evaluations. Further research appears warranted to support SWAY as a method of diagnosing concussion and monitoring return to baseline.

A - 12 Pre-existing Anxiety and Vestibular Symptoms: The Relationship to Balance and Reaction Time in College Athletes

Abstract Objective Pre-existing physical and mental health conditions can contribute to deficits in reaction time and balance among athletes. The purpose of this study was to investigate whether athletes who endorsed symptoms of anxiety and/or vestibular dysfunction would have slower reaction time and worse balance than athletes who did not. Methods College athletes (n = 361) at the Florida Institute of Technology who completed a pre-participation baseline evaluation including the Patient Health Questionnaire (PHQ-9), Sport Concussion Assessment Tool (SCAT-5) Baseline version, Balance Error Scoring System (BESS), General Anxiety Disorder Seven Item Scale (GAD-7), and Sway Balance App. Results T-tests indicated athletes who endorsed no anxiety were shown to have better balance on Sway than athletes who endorsed at least one symptom of anxiety, (t(237) = 2.73, p = 0.007, d = 0.31. Athletes who endorsed no vestibular symptoms were also shown to have better balance on Sway than those who endorsed at least one vestibular symptom, t(359) = 2.14, p = 0.03, d = 0.27. Correlational results demonstrated as symptoms of anxiety (r = −0.21, n = 361, p &amp;lt; 0.001) or vestibular dysfunction (r = −0.15, n = 361, p = 0.006) increase, balance performance on Sway decreases. Post-hoc Tukey indicated athletes who endorsed either anxiety or vestibular symptoms had lower scores and thus worse balance on Sway than athletes who endorsed no symptoms (p = 0.009). Conclusions Findings suggest that pre-existing anxiety and vestibular symptoms have a negative impact on balance, supporting need for their inclusion in athletic concussion testing protocols.

Untreated adolescent idiopathic scoliotic girls display altered balance modalities during self-paced voluntary body sways compared to able-bodied girls

IntroductionThis study investigated self-paced voluntary oscillations of scoliotic and non-scoliotic girls. Temporal variables and frequency coherence were calculated for the overall, low and high frequency bandwidths of the center of pressure excursions and free-moment to identify which variables best describe sway balance modalities in both groups. MethodsTwenty-three girls with adolescent idiopathic moderate scoliosis (spinal curves to the right) formed the scoliotic group and 19 matched able-bodied girls formed the non-scoliotic group. Each girl performed self-paced voluntary medio-lateral and antero-posterior sways while standing on a force platform. Center of pressure displacements, out of plane deviation and free-moment were measured and their frequency content calculated. The magnitude of the coherence was calculated for each signal pairs for three frequency ranges. ResultsIn both sway conditions, the center of pressure excursion parameters were on average 28% higher for the scoliotic group. Factor analysis revealed that balance modalities were essentially based on frequency coherence pair interactions whereas temporal parameters play a secondary role. However, these balance modalities were altered in the scoliotic group. They relied essentially on 2 additional principal components and 3 additional variables reflecting a fine tuning of the control mechanism to maintain dynamic balance. InterpretationScoliotic girls appear to be performing a wide ellipsoidal trajectory when performing whole body oscillations. Superfluous variables could be related to the difficulty in preserving balance during body sway tasks and could parasitize the scoliotic dynamic control balance modalities. Self-paced voluntary sways could be an appropriate complementary balance test for untreated scoliotic girls.

Visuo-postural dependency index (VPDI) in human postural control

BackgroundComputerized stabilometry has been utilized to investigate the effect of vision on the neuromechanisms of human postural control. However, this approach lacks operational methods to quantify visual dependency during upright stance. This study had three goals: (1) To introduce the concept of visuo-postural dependency indices (VPDI) representing balance sway characteristics in multiple analytical domains (spatial, temporal, frequency, and structural), (2) To investigate the age and gender effects on VPDIs, and (3) To investigate the degree of relationships between VPDI and both subjective visual vertical and horizontal perception (SVV and SVH, respectively).Methods102 participants (16 to 80 years old) performed bipedal stances on a force platform with eyes open and closed. Response variables included the VPDIs computed for each postural index. In addition, 29 participants also performed SVV and SVH assessments.ResultsFifteen VPDIs showed to be robust indicators of visual input modulation, and the variation across their magnitudes of modulation revealed a non-homogeneous response to changes in visual stimuli. Gender and age were not found to be a significant factor to VPDI modulation.ConclusionsVPDIs revealed to be potential measures capable to quantitatively assess visuo-postural dependency and aid the assessment of fall risks and balance impairments.

An Accessible Training Device for Children With Cerebral Palsy.

Walking and balance capabilities can be improved upon using repetitive ankle dorsiflexion exercises. Here we developed two types of pedal switches incorporated with training devices to improve their walking and balance performance of children with cerebral palsy. The first type of pedal switch can be used to operate a home appliance, while the second type of pedal switch can connect them to web games. Pedal switches can be used for home rehabilitation. This randomized controlled trial included patients in the intervention (n = 24) and control (n = 24) groups who completed 15 weeks of ankle training. The experimental group performed ankle dorsiflexion using a pressure-activated pedal switch connected to the web games. The control group performed ankle dorsiflexion exercises using a pedal switch that operated a home appliance (a fan). Standing balance and walking performance were estimated using the Zebris FDM system, a pressure force platform, the Pediatric Balance Scale score, and the 1-minute walk test. The pre- and posttest data were analyzed using analysis of variance and analysis of covariance, which revealed that the intervention group had more significant improvements in sway patterns and balance and walking. The developed facility of a modified pedal switch integrated with web games can achieve better exercise adherence to promote balance and walking performance than that with home appliances. Maintaining motivation in children with cerebral palsy plays a very important role in the rehabilitation process.

The Effect of an Interactive Tele Rehabilitation Program on Balance in Older Individuals

Objective: To investigate the effect of a home-based interactive telerehabilitation program on balance performance in older people, and to compare the results with a nonsupervised home exercise (NHE) program. Subjects and Methods: A total of 50 participants (35 females), aged 65–90 years, were included in the study. The subjects were randomly assigned to one of three groups as the interactive telerehabilitation home exercise group (ITHE), NHE group or control group. The ITHE and NHE groups exercised three times per week for 8 weeks. The outcome measures were the Berg Functional Balance Scale (BBS), Timed Up and Go Test (TUG), Sway Balance Mobile Application, Trait Anxiety Inventory (TAI), and the World Health Organization Quality of Life Instrument-Older Adults Module (WHL). Results: In the control group, no difference was observed in the TUG and BBS scores, at the end of the 8 weeks compared with preexercise (pre-ex), whereas these scores increased significantly in the NHE (TUG: P &lt; 0.001, BBS: P &lt; 0.001) and ITHE groups (TUG: P &lt; 0.001, BBS: P = 0.003). The WHL scores increased significantly in all three groups, and no difference was observed in the TAI scores. There was a significant difference in SWAY score only in the telerehabilitation group compared with pre-ex (P &lt; 0.001). Conclusions: Although NHE and ITHE were effective on the improvement of balance, mobility and reduction of fall risk in older individuals, this effect was found to be greater in the ITHE group. Quality of life increased in all groups, but no change in anxiety level was observed.

Elamipretide Prevents the Natural History Progression of Cardiomyopathy-Related Disease Symptomatology in Patients with Barth Syndrome: A Tazpower Analysis

Introduction Barth Syndrome (BTHS) is an X-linked disease caused by defects in TAZ, the tafazzin encoding gene that creates mature cardiolipin. Clinical manifestations of cardiac/skeletal myopathy, neutropenia, and growth abnormalities result from immature cardiolipin. Elamipretide (ELAM) localizes to the inner mitochondrial membrane and associates with cardiolipin to improve mitochondrial membrane stability/ATP production. Hypothesis TAZPOWER evaluated the efficacy/tolerability of ELAM in BTHS. Methods Randomization: 1:1 to SQ ELAM 40mg once daily for 12wks, then placebo for 12wks, after a 4-wk washout period, or vice versa, in a blinded, crossover design (Part 1); Part 1 patients enrolled in an open-label extension (OLE; Part 2). FDA guidance supports using natural history controls (NHCs) providing external control grps with matched propensity scores for drug development in interventional, rare-disease studies. ELAM's effect on BTHS symptoms and cardiomyopathy at OLE wk 36 were compared to NHC patients. We used 4 domains of primary (6 minute walk test [6MWT]) and secondary (muscle strength by HHD, 5XSST [Five Times Sit to Stand], SWAY balance) functional outcomes. A correlation between functional assessments and heart function may exist; the relationship of stroke volume improvement to stroke volume was also evaluated. Results At OLE wk-36 baseline, ELAM-treated (N = 8) and NHC BTHS patients (N = 19) with similar between-grp prognostic covariates (age, 6MWT), performed poorly on functional assessments, and had pathologic exercise symptoms of heart failure with normal ejection fractions. At baseline, subjects showed markedly reduced indexed LV end-systolic and end-diastolic volumes resulting in markedly reduced stroke volumes. At OLE wk 36, ELAM-treated patients showed significantly greater mean improvements from baseline vs. NHC patients in 6MWT, muscle strength by HHD, 5xSST, and MDRI . Between-group difference in sway balance was not significant. Improvements in stroke volume appear to coincide with observed improvements in functional domain outcomes. Long-term ELAM-treated subjects showed significant increases in LVEDV, LVESV and avg indexed stroke volume . Treatment-emergent (91) and serious AEs (1, unrelated to ELAM) were reported, with injection site reactions being the most commonly reported AE. Conclusions In TAZPOWER OLE, ELAM was well tolerated and associated with large and statistically significant improvements vs. NHC in functional assessments after 36wks. LVEDV and stroke volume increases (major determinants of peak exercise capacity in hypertrophic cardiomyopathy) were also observed. Results demonstrate that BTHS patients on long-term ELAM therapy experience improvement in multiple disease-related symptoms, including cardiac function.

Normative Data for the Sway Balance System

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. Cross-sectional study. Middle and high schools across the United States. Participants were 3763 youth aged 9 to 21 years who completed the Sway Balance System Sports protocol in accordance with the company's recommended methods (ie, 1 acclimation trial and 2-3 baseline tests). Age and sex. Sway Balance score (0-100) and Sway Reaction Time score (0-100). A multivariate analysis of variance examined the effects of age and sex on balance and reaction time scores. Sway Balance and Reaction Time scores significantly differed by age [F(10, 7494) = 39.68, P < 0.001, V = 0.10, = 0.05] and sex [F(4, 7494) = 55.29, P < 0.001, V = 0.06, = 0.03]. Post hoc analyses revealed that older groups generally had better scores than younger groups on all balance comparisons (ps < 0.001) and many reaction time comparisons. Girls performed better than boys on balance [F(2, 3747) = 53.79, P < 0.001, = 0.03] and boys had faster reaction times [F(2, 3747) = 37.11, P < 0.001, = 0.02]. 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.

Comparison Of Age, Gender, And Sport On Performance Of Stability Test In Senior Participants

PURPOSE: The purpose of this study was threefold: to observe the differences in performance variables of the Modified Clinical Test of Sensory Interaction in Balance in active elderly participants and to compare results by age (50-59, 60-69, 70-79, 80+), sports (aerobic, basketball, golf, tennis, volleyball, and none), and gender. METHODS: Anlayses were based on a sample of 525 World Senior Games attendees who were age 50 and over. Data were obtained from voluntary participation in balance and mobility screening as part of the health fair offered to all participants at the annual Hunstman World Senior Games. Of the 525 participants tested, 383 were participants in at least one sporting event at the games and 142 were non-participants. All modified CTSIB were performed on the NeuroCom Balance Master. The measured variables (center of gravity sway (degrees/sec)) were; firm surface with eyes open, firm surface with eyes closed, foam surface with eyes open, and foam surface with eyes closed. RESUTS: All data were analysed using SAS, version 9.4. An initial analysis of gender and age category was performed. A final model was run with the significant variables from the initial analysis plus sports category. Post hoc Tukey pairwise comparisons were also performed. A significant difference ∗(p<0.0001) was found between stratified age groups in all balance test variables. No significant differences were found between gender nor sports categories for the 4 balance variables.CONCLUSION: While balance sway significantly increases with age in all 4 variables, they remain similar when comparing between gender and sports. This test may not be sensitive enough to detect differences between sports in our participants. Also, our participants are probably too active to detect differences in the variables tested regardless of sports category. Further research is needed to better differentiate between active and non-active individuals and performance on the modified CTSIB.

Effects of performing dual tasks on postural sway and postural control complexity in people with haemophilic arthropathy.

People with haemophilic arthropathy (PWHA) have impairments in postural control. However, little is known about the effects of demanding conditions, including the unipedal stance and dual tasks, on postural control in PWHA. Determine the effects of performing dual tasks while in the one-leg stance on postural sway and postural control complexity in PWHA vs. healthy active (HAG) and non-active (HNAG) groups of individuals. Fifteen PWHA and 34 healthy subjects (18 active and 16 non-active) were recruited. Vertical (V), mediolateral (ML) and anteroposterior (AP) centre of mass signals were acquired using a 3-axis accelerometer placed at the L3/L4 vertebrae of subjects as they performed the one-leg stance under single and dual-task conditions. Sway balance and the complexity of postural control were studied via root mean square (RMS) acceleration and sample entropy, respectively. Increased complexity of postural sway was attributed to increased automatism of postural control. RMS values for PWHA were higher than HAG under both conditions for the V and ML axes, and higher than HNAG under the dual-task condition for the ML axis. Sample entropy was lower in PWHA than healthy individuals under the dual-task condition for V and ML axes, and the single-task condition for the ML axis (P<.05). PWHA had poorer postural sway and decreased postural control complexity when performing a one-leg stance than healthy people, especially when the dual-task condition was applied. These results may help to design new approaches to assess and improve postural control in PWHA.

Effects of different types of proprioceptive neuromuscular facilitation stretching on dynamic balance control

The aim of this study was to compare the effectiveness of acute of contract–relax (CR) and contract–relax–antagonist–contraction (CRAC) targeting the quadriceps, hamstrings, anterior tibialis, and calf muscles and warm-up without stretching on medio-lateral (ML) and antero-posterior (AP) dynamic balance control in healthy young men applied by a physiotherapist in comparison to a control intervention without stretching. Twenty healthy young men between the age of 18 and 25 performed three interventions in randomized days after standard warm-up: CR intervention, CRAC intervention, and control intervention. ML and AP dynamic balance control was carried out before (Pre) and immediately after (Post) each intervention. Antero-posterior sway (AP sway) and medio-lateral sway (ML sway) under vision and no vision condition were analyzed by posturography. CRAC intervention improved significantly ML dynamic balance control by decreasing ML sway (vision, p = 0.006 and no vision, p < 0.001) and AP sway (vision, p = 0.013 and no vision, p < 0.001). In addition, ML dynamic balance sway was significanly lower after CRAC intervention than control intervention (vision, p < 0.001 and no vision, p < 0.001). In AP dynamic balance control, no effect of CR and CRAC interventions was detected. CRAC stretching of the quadriceps, hamstrings, anterior tibialis, and calf muscles improved ML dynamic balance.

Reliability of a New Test of Balance Function in Healthy and Concussion Populations.

Providing quantitative measures of balance and posture is a valuable aid in clinical assessment and in recent years several devices have been introduced that have demonstrated the accurate measure of balance via deviation of center of mass utilizing software algorithms and mobile devices. The purpose of this study was to assess the accuracy of EQ Balance against the SwayTM Balance System (Sway), another balance device that is currently established as an accurate measure of balance, and to evaluate the test–retest reliability of EQ Balance. Seventy individuals presenting to a sports medicine and concussion clinic volunteered to participate in the assessment of balance utilizing Sway and EQ Balance simultaneously. The group included 25 males and 45 females (mean age: 37.8 ± 14.8, range: 13–65) with and without concussion or other neurological conditions (39 concussed vs. 31 non-neurologically injured, or healthy). Twenty-six of the concussed participants were balance-impaired. Participants performed five postures while holding the mobile device against their chest. Participants held a device holder that secured two devices: one iPhone 6 with EQ Balance and a second iPhone 6 with Sway Balance. The average balance score on all five stances was recorded as the “average balance score”. Average balance scores were in statistical agreement between the two methods across the entire group, and for sub-groups according to the Deming regression (p < 0.01). The intra-class correlation (ICC) for the cohort was 0.87 (p < 0.001). Across the cohort, EQ Balance measured significantly worse balance scores in the balance-impaired group, comprised of participants with brain injury who failed a clinical balance screening test, compared to the group without clinically-determined balance impairment (this group includes healthy and some concussed patients). EQ Balance demonstrated safety, as it was considered safe to perform independently (i.e., without an observer) in those with impaired balance, and high test- retest reliability in the healthy and concussed patient population. Statistical agreement was established between the two measures of EQ Balance and Sway Balance for the average balance score across all five stances. The ICC analysis demonstrates strong consistency of the task output between test sessions. Given these results, EQ Balance demonstrates strength as a new balance assessment tool to accurately measure balance performance as part of a unique and novel gamified application in healthy and neurologically injured populations.

Kinematic Validation of Postural Sway Measured by Biodex Biosway (Force Plate) and SWAY Balance (Accelerometer) Technology.

Background The Biodex Biosway® Balance System and SWAY Balance® Mobile smartphone application (SBMA) are portable instruments that assess balance function with force plate and accelerometer technology, respectively. The validity of these indirect clinical measures of postural sway merits investigation. Purpose The purpose of this study was to investigate the concurrent validity of standing postural sway measurements by using the portable Biosway and SBMA systems with kinematic measurements of the whole body Center of Mass (COM) derived from a gold-standard reference, a motion capture system. Study Design Cross-sectional; repeated measures. Methods Forty healthy young adults (21 female, 19 male) participated in this study. Participants performed 10 standing balance tasks that included combinations of standing on one or two legs, with eyes open or closed, on a firm surface or foam surface and voluntary rhythmic sway. Postural sway was measured simultaneously from SBMA, Biosway, and the motion capture system. The linear relationships between the measurements were analyzed. Results Significant correlations were found between Biosway and COM velocity for both progressively challenging single and double leg stances (τb = 0.3 to 0.5, p < 0.01 to <0.0001). SBMA scores and COM velocity were significantly correlated only for single leg stances (τb = −0.5 to −0.6, p < 0.0001). SBMA scores had near-maximal values with zero to near-zero variance in double leg stances, indicating a ceiling effect. Conclusion The force plate-based Biodex Biosway is valid for assessing standing postural sway for a wide range of test conditions and challenges to standing balance, whereas an accelerometer-based SWAY Balance smartphone application is valid for assessing postural sway in progressively challenging single leg stance but is not sensitive enough to detect lower-magnitude postural sway changes in progressively challenging double leg stances.

Postural Control Responses to Different Acute and Chronic Training Load Profiles in Professional Rugby Union.

Troester, JC and Duffield, R. Postural control responses to different acute and chronic training load profiles in professional rugby union. J Strength Cond Res 36(1): 220-225, 2022-The current investigation identified the response of postural control (PC) measures of single-leg balance and landing to different accumulated training load profiles representing normal, higher, and spiked loads. Twenty-two professional rugby union players performed single-leg balance and landing tests on a 1,000-Hz force plate on the first training day of 24 weeks across the season after 36 hours of recovery. Internal (session rating of perceived exertion training load) and external (total and high-speed running distance) load measures were monitored during all training sessions and matches. Calculations of acute (7-day rolling average), chronic (28-day rolling average), and acute-to-chronic workload ratio were determined. Three-week load profiles were identified that represented normal, spike, and higher load profiles to determine the effect on PC, which were analyzed using 2-way repeated-measures analysis of variance. A significant effect of load profile on landing impulse on the dominant (p = 0.005) and nondominant legs (p = 0.001) was identified, with significantly greater impulse measures in the spike and higher load profiles (p = 0.001-0.041) compared with the normal load profile. Significant load profile × week interactions (p < 0.05) were identified for landing peak force on the dominant leg and impulse on both legs suggesting a decrement during the spike load profile and increased impulse in the higher load profile. No effects (p > 0.05) were identified for load profile changes in single-leg balance sway velocity or single-leg landing time to stabilization. The respective landing responses may indicate altered movement strategies under spike and higher load profiles resulting from neuromuscular fatigue in response to the accumulated load.

Normative Data Set of SWAY Balance Mobile Assessment in Pediatric Athletes.

To examine and describe normative values for an objective, mobile measure of postural stability commonly used in concussion assessments, SWAY Balance (SWAY Medical, Tulsa, Oklahoma). Retrospective analysis of baseline balance assessments in a healthy pediatric population. 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. 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. Normative, age-specific SWAY Balance test results provided are of clinical use as references in the concussion assessments of pediatric athletes.