Mediolateral Sway Research Articles

Effects of Differential Jump Training on Balance Performance in Female Volleyball Players

The purpose of this study was to determine whether coordinative jump training that induces neuromuscular stimuli can affect balance performance, associated with injury risk, in elite-level female volleyball players. During the competitive season, the balance performance of 12 elite female players (highest Austrian division) was obtained via a wobble board (WB; 200 Hz) placed on an AMTI force plate (1000 Hz). Three identically repeated measurements defined two intervals (control and intervention phases), both comparable in duration and regular training. The intervention included 6 weeks of differential training (8 sessions of 15–20 min) that delivered variations in dynamics around the ankle joints. Multilevel mixed models were used to assess the effect on postural control. WB performance decreased from 27.0 ± 13.2% to 19.6 ± 11.3% during the control phase and increased to 54.5 ± 16.2% during the intervention (β = 49.1 ± 3.5; p < 0.001). Decreased sway area [cm²] (β = −7.5 ± 1.6; p < 0.001), anterior–posterior (β = −4.1 ± 0.4; p < 0.001) and mediolateral sway [mm] (β = −2.7 ± 0.6; p = 0.12), and mean velocity [mm∙s−1] (β = −9.0 ± 3.6; p < 0.05) were observed during the intervention compared with the control phase. Inter-limb asymmetry was reduced (β = −41.8 ± 14.4; p < 0.05). The applied training concept enhanced balance performance and postural control in elite female volleyball players. Due to the low additional physiological loads of the program and increased injury risk during the competitive season, we recommend this intervention for supporting injury prevention during this period.

Multiscale entropy derived complexity index analysis demonstrates significant mediolateral sway in persons with multiple sclerosis compared to healthy controls.

Clinical assessment of Multiple Sclerosis relies heavily on the Expanded Disability Status Scale, a non-linear rating system based on physician assessment of disease progression and walking ability. This inherently makes this method both subjective and limited in repeatability. This study developed a technically derived outcome measure of posture to compare a cohort of Multiple Sclerosis and Control subjects during an Eyes-Open and Eyes-closed task. Analysing traditional sway parameters and a multiscale entropy derived complexity index of posturography showed a significant difference in medio-lateral sway between groups during the Eyes-Open condition. This technically derived outcome measure may be of clinical benefit in the longitudinal assessment of the functional impact of balance in MS cohorts and assist in the evaluation of pharmaceutical and rehabilitation interventions.

Postural Stability and Dynamic Balance in Adult Spinal Deformity: Prospective Pilot Study

We sought to evaluate dynamic balance and postural stability in patients with adult spinal deformity (ASD) compared with published age-matched normative data. Eleven patients with ASD were prospectively enrolled. Postural stability was tested using static and dynamic posturography; patients stood on a movable platform with an integrated force plate and performed standardized sensory organization testing (SOT), evaluating the influence of sensory processing on postural stability under 6 conditions, and motor control testing, assessing reflexive postural reactions to an external perturbation. Patient performance was compared with that of published age-matched controls. Quality of life metrics included scores on the Scoliosis Research Society-22 questionnaire, SF-36, and Morse Fall Scale. Correlations between postural stability and radiographic measurements were performed. ASD patients demonstrated significantly lower SOT scores (P ≤ 0.03) in 5 of 6 conditions tested and greater latency of limb movement during backward translation (P= 0.04) compared with controls. Lower SOT scores were associated with a history of falls. ASD patients who self-reported falling in the previous 6 months, when compared with nonfallers, demonstrated significantly lower SOT scores (P= 0.04) and significantly lower Scoliosis Research Society-22 self-image subscores (P= 0.003). Thoracic kyphosis and mediolateral sway (predictor of falls) were positively correlated in the eyes-open and eyes-closed conditions (P ≤ 0.04). ASD patients demonstrated impaired postural stability, diminished sensory integration, and delayed response to external perturbations compared with normal control data. Postural stability and quality of life metrics correlated with self-reported falls. These findings suggest that ASD patients have abnormal postural stability and may be at elevated risk of falls.

Visceral Mobilization and Functional Constipation in Stroke Survivors: A Randomized, Controlled, Double-Blind, Clinical Trial

IntroductionChronic functional constipation is common among stroke survivors. Osteopathy is an effective form of treatment as it acts on the structures surrounding the bowels that may have lost their normal capacity of resilience. The aim of the present study was to evaluate the effect of visceral mobilization on symptoms of functional constipation and static balance in stroke survivors.Materials and methodsThirty stroke survivors met the eligibility criteria and were randomly allocated to a group physical therapy and visceral manipulation or a group physical therapy. Both groups were submitted to conventional physical therapy. The group physical therapy and visceral manipulation was also submitted to visceral mobilization (sphincter inhibition and mobilization of the large intestine), whereas the group physical therapy was submitted to a sham procedure (superficial touching over the intestines). Evaluations were conducted prior to the intervention, immediately after the first intervention session and one week after the end of the five sessions. At each evaluation, the static balance was analyzed using a computerized plantar pressure sensor. Moreover, an intestinal symptoms rating scale was administered during the pre-intervention evaluation, and one week after the end of the intervention.ResultsSignificant improvements were found in intestinal symptoms (frequency of bowel movements, abdominal pain/discomfort, difficulty eliminating stools, sensation of intestinal swelling or distention, difficulty eliminating gas, sensation of incomplete bowel movement and, anal pain during bowel movement) and static balance (anteroposterior sway: F = 82.06, p = 0.0001; velocity of anteroposterior sway: F = 17.6, p = 0.001; and velocity of mediolateral sway: F = 4.41, p = 0.01).ConclusionVisceral mobilization can be part of a neurologic rehabilitation program to improve symptoms of constipation and static balance in stroke survivors.

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.

Effectiveness of an Unexpected Disturbance Program in the Early Stage of Rehabilitation in Athletes With Unilateral Knee Ligament Injury.

Sensorimotor, proprioceptive, and neuromuscular programs are critical for the successful rehabilitation of injured athletes, and these decrease reinjury rates. To investigate the effects of an unexpected disturbance program (UDP) on balance and unilateral strength metrics in athletes with unilateral knee ligament injury. A 3-week parallel-group experimental design consisting of 9 rehabilitation sessions. National Sports Institute. Twenty-one national-level athletes (age 21.4 [4.4]y, body mass 63.9 [10.8]kg, height 169.0 [10.2]cm) who had sustained a unilateral knee ligament injury. An UDP program designed to evoke rapid sensorimotor responses was compared with traditional training and a nonexercise control group. Unilateral total, anteroposterior, and mediolateral sway with eyes open and closed and unilateral isometric strength. Traditional exercises tended to outperform the UDP when unilateral balance testing was performed with eyes open; however, balance improvement following UDP tended to be greater in the eyes-closed condition. Significant strength gains in both the injured and uninjured legs were only observed following the UDP. This increase in unilateral isometric strength was 23.4 and 35.1 kg greater than the strength improvements seen in the traditional rehabilitation and control groups (P < .05). UDP could improve neural aspects of rehabilitation to improve rehabilitation outcomes by improving strength, sensorimotor function, and proprioception. Given the complementary adaptations, an UDP could provide an effective adjunct to traditional rehabilitation protocols and improve return-to-play outcomes.

Postural control processes during standing and step initiation in autism spectrum disorder

BackgroundIndividuals with autism spectrum disorder (ASD) show a reduced ability to maintain postural stability, though motor control mechanisms contributing to these issues and the extent to which they are associated with other gross motor activities (e.g., stepping) are not yet known.MethodsSeventeen individuals with ASD and 20 typically developing (TD) controls (ages 6–19 years) completed three tests of postural control during standing. During the neutral stance, individuals stood with their feet shoulder width apart. During the Romberg one stance, they stood with feet close together. During the circular sway, participants stood with feet shoulder width apart and swayed in a circular motion. The standard deviation (SD) of their center of pressure (COP) in the mediolateral (ML) and anteroposterior (AP) directions and the COP trajectory length were examined for each stance. We also assessed mutual information (MI), or the shared dependencies between COP in the ML and AP directions. Participants also completed a stepping task in which they stepped forward from one force platform to an adjacent platform. The amplitude and duration of anticipatory postural adjustments (APAs) were examined, as were the maximum lateral sway, duration, and velocity of COP adjustments following the initial step. We examined stepping variables using separate one-way ANCOVAs with height as a covariate. The relationships between postural control and stepping measures and ASD symptom severity were assessed using Spearman correlations with scores on the Autism Diagnostic Observation Schedule–Second Edition (ADOS-2) and the Autism Diagnostic Interview-Revised (ADI-R).ResultsIndividuals with ASD showed increased COP trajectory length across stance conditions (p = 0.05) and reduced MI during circular sway relative to TD controls (p = 0.02). During stepping, groups did not differ on APA amplitude (p = 0.97) or duration (p = 0.41), but during their initial step, individuals with ASD showed reduced ML sway (p = 0.06), reduced body transfer duration (p < 0.01), and increased body transfer velocity (p = 0.02) compared to controls. Greater neutral stance COPML variability (r = 0.55, p = 0.02) and decreased lateral sway (r = − 0.55, p = 0.02) when stepping were associated with more severe restricted and repetitive behaviors in participants with ASD.ConclusionsWe found that individuals with ASD showed reduced MI during circular sway suggesting a reduced ability to effectively coordinate joint movements during dynamic postural adjustments. Additionally, individuals with ASD showed reduced lateral sway when stepping indicating that motor rigidity may interfere with balance and gait. Postural control and stepping deficits were related to repetitive behaviors in individuals with ASD indicating that motor rigidity and key clinical issues in ASD may represent overlapping pathological processes.

Static balance in older adults with chronic obstructive pulmonary disease undergoing pulmonary rehabilitation

OBJECTIVE: To compare balance between older adults with and without chronic obstructive pulmonary disease (COPD) in tasks involving proprioceptive changes and respiratory muscle load, and to investigate the association between balance, functional capacity, and peripheral and respiratory muscle strength. METHODS: Fourteen older adults with COPD undergoing pulmonary rehabilitation and nine older adults without pulmonary disease were evaluated for static balance on a force platform under four conditions: eyes open, eyes closed, eyes closed on foam, and eyes open with respiratory overload. Differences between groups, among conditions and group/condition interactions, were tested using two-way ANOVA. Associations were explored using Pearson’s correlation coefficient. RESULTS: No differences in the posturographic variables were found in the group/condition interactions (p ≥ 0.23). The COPD group exhibited greater total displacement (F = 8.79, p = 0.003), mediolateral sway (F = 4.01, p = 0.04) and anteroposterior velocity (F = 4.28, p = 0.04) in the group effect analysis. Significant differences were found between eyes closed on foam and other conditions for all posturographic variables: anteroposterior sway (F = 13.39), mediolateral sway (F = 28.58), total displacement (F = 59.4), area (F = 37.68), anteroposterior velocity (F = 26.42), and mediolateral velocity (F = 33.29), in the condition effect analysis (p &lt; 0.001, post-hoc). In the COPD group, significant correlations were found between the Glittre-ADL test, anteroposterior sway (r = 0.68, p = 0.01), and anteroposterior velocity (r = 0.67, p = 0.009); the 6MWT was also correlated with anteroposterior velocity (r = 0.59, p = 0.03). CONCLUSION: Older adults with COPD present balance deficits compared to healthy individuals. The unstable surface caused greater postural instability compared to other conditions in both groups. Impaired balance was associated with reduced physical function and exercise capacity.

20 Optic Flow Stimuli Effects on Standing Balance in Young and Older People with Low and High Fall Risk

Abstract Introduction Optic flow stimuli can destabilise postural control, especially those with increased visual field dependence. This study aimed to examine the effects of optic flow stimuli on postural stability between: 1) younger and older adults; and 2) low-falls-risk and high-falls-risk older adults. Methods 76 participants were grouped into ‘young’ (20-40 years, n=25), and ‘old’ (≥65 years, n=51); the latter was further stratified into ‘old-LFR’ (low fall risk, n=27) and ‘old-HFR’ (high fall risk, n=24). Participants stood on a force platform in a dark room with motion capture markers on the head, torso and lower limb. Optic flow stimuli were projected on a large screen encompassing the field of view as moving white dots for 30 seconds in four different conditions: radial expansion, radial contraction, circular (roll vection) anticlockwise and circular clockwise. Postural control was calculated from center of pressure (COP) and lower limb joint and trunk angles; changes between baseline (static dots) and optic flow conditions were compared between groups. Results Optic flow stimuli led young and older participants to shift their COP in the expected direction for each stimulus condition (forward for expansion, backward for contraction, left for anticlockwise, right for clockwise). For radial expansion, significantly increased anteroposterior sway was found in old-LFR and old-HFR (p≤0.001) but not \young (p≥0.17). Similar results were seen for radial contraction. For circular clockwise, significantly increase mediolateral sway was found in old-HFR (p=0.002) but not young (p=0.912) or old-LFR (p=0.749). Results differed for circular anticlockwise, with greater changes seen in anteroposterior sway compared with mediolateral, particularly in old-HFR. No stimuli by group interaction effects were seen in body kinematics. Conclusions Optic flow stimuli have a more destabilising effect on balance in older than younger adults, particularly those at increased risk of falling.

Psychiatric Patients on Neuroleptics: Evaluation of Parkinsonism and Quantified Assessment of Gait.

We aimed to characterize parkinsonian features and gait performance of psychiatric patients on neuroleptics (PPN) and to compare them to Parkinson's disease (PD) and healthy controls (HC). Hospitalized PPN (n = 27) were recruited, examined, and rated for parkinsonian signs according to the motor part of the Movement Disorders Society Unified Parkinson's Disease Rating Scale and performed a 10-m "timed-up-and-go" (TUG) test with a smartphone-based motion capture system attached to their sternum. Gait parameters and mUPDRS scores were compared to those of consecutive age-matched PD patients (n = 18) and HC (n = 27). Psychiatric patients on neuroleptics exhibited parkinsonism (mUPDRS score range: 8-44) but less than that of PD patients (18.2 ± 9.2 vs 29.8 ± 10.3, P = 0.001). TUG times were slower for PPN and PD versus HC (total: 30.6 ± 7.6 seconds vs 30.0 ± 7.3 seconds vs 20.0 ± 3.2 seconds, straight walking: 10.6 ± 2.7 seconds vs 10.6 ± 2.4 seconds vs 6.8 ± 1.2 seconds) (P < 0.001), and cadence and step length were similar among PPN and PD and different from HC as well. Although their gait speed was slower than HC but similar to PD, PPN had lower mediolateral sway (4.3 ± 1.1 cm vs 6.7 ± 2.9 cm vs 6.9 ± 2.9 cm, respectively, P < 0.001) than both. Parkinsonism is very common in hospitalized PPN, but usually milder than that of PD. It seems that wearable sensor-based technology for assessing gait and balance may present a more sensitive and quantitative tool to detect clinical aspects of neuroleptic-induced parkinsonism than standard clinical ratings.

Fall Risk Prediction in Multiple Sclerosis Using Postural Sway Measures: A Machine Learning Approach

Numerous postural sway metrics have been shown to be sensitive to balance impairment and fall risk in individuals with MS. Yet, there are no guidelines concerning the most appropriate postural sway metrics to monitor impairment. This investigation implemented a machine learning approach to assess the accuracy and feature importance of various postural sway metrics to differentiate individuals with MS from healthy controls as a function of physiological fall risk. 153 participants (50 controls and 103 individuals with MS) underwent a static posturography assessment and a physiological fall risk assessment. Participants were further classified into four subgroups based on fall risk: controls, low-risk MS (n = 34), moderate-risk MS (n = 27), high-risk MS (n = 42). Twenty common sway metrics were derived following standard procedures and subsequently used to train a machine learning algorithm (random forest – RF, with 10-fold cross validation) to predict individuals’ fall risk grouping. The sway-metric based RF classifier had high accuracy in discriminating controls from MS individuals (>86%). Sway sample entropy was identified as the strongest feature for classification of low-risk MS individuals from healthy controls. Whereas for all other comparisons, mediolateral sway amplitude was identified as the strongest predictor for fall risk groupings.

Effects of augmenting cholinergic neurotransmission on balance in Parkinson's disease

IntroductionDegeneration of cholinergic systems may contribute to impairments of balance and gait in Parkinson's disease (PD) and phase 2 clinical trials have suggested that centrally acting cholinesterase inhibitors reduce falls. Here, we examined the effects of augmenting cholinergic neurotransmission on static and dynamic balance, indices of fall risk. MethodsA single-site, randomized, double-blind, crossover trial examined the effect of donepezil in patients with PD. Forty-nine participants with idiopathic PD were randomized and 45 completed the trial. Each treatment period was 6 weeks with a 6-week washout between treatments. Donepezil in 2.5 mg capsules, or identical appearing placebo capsules, was increased from two per day (5 mg) to four capsules (10 mg) after 3 weeks. The primary outcome measures were the range of the medio-lateral sway when standing (static balance) and the variability of the stride duration when walking (dynamic balance). A linear mixed model was used to investigate whether the change in outcomes between weeks 0 and 6 differed between phases. ResultsThere were no significant differences in treatment effects between placebo and donepezil for medio-lateral sway range during quiet standing (p = 0.28), nor in gait variability (p = 0.31). None of the secondary outcome measures or exploratory analyses were significant although one secondary measure of static balance was increased by donepezil. ConclusionsContrary to our hypothesis, cholinergic augmentation with donepezil at 10 mg/day for 6 weeks did not affect measures of static or dynamic balance in people with PD. These results are compared with other phase 2 trials of cholinesterase inhibitors and considerations for future trials are discussed.

Complexity based measures of postural stability provide novel evidence of functional decline in fragile X premutation carriers

BackgroundFragile X Associated Tremor/Ataxia Syndrome (FXTAS) is a neurodegenerative movement disorder characterized by tremor, ataxic gait, and balance issues resulting from a premutation of the Fragile X Mental Retardation 1 (FMR1) gene. No biomarkers have yet been identified to allow early diagnosis of FXTAS, however, recent studies have reported subtle issues in the stability of younger premutation carriers, before disease onset. This study investigates the efficacy of multiscale entropy analysis (MSE) in detecting early changes in the motor system of premutation carriers without FXTAS.MethodsSway complexity of 12 female Premutation carriers and 15 healthy Controls were measured under four conditions: eyes open, closed, and two dual-task conditions. A Sustained Attention Response Task (SART) and a working memory based N-Back task were employed to increase cognitive load while standing on the forceplate. A Complexity Index (Ci) was calculated for anterior-posterior (AP) and mediolateral (ML) sway. Independent t-tests were used to assess between-group differences and Oneway repeated measures ANOVA were used to assess within group differences with Bonferroni corrections to adjust for multiple comparisons.ResultsGroup performances were comparable with eyes open and closed conditions. The Carrier group’s Ci was consistent across tasks and conditions while the Control group’s AP Ci increased significantly during the cognitive dual-task (p = 0.001). There was also a strong correlation between CGG repeat length and complexity for the Carrier group (p = 0.004).SignificanceIncreased sway complexity is believed to stem from reallocation of attention to facilitate the increased cognitive demands of dual-tasks. Carriers’ complexity did not change during dual-tasks, possibly indicating capacity interference and inefficient division of attention. Lower sway complexity in carriers suggests diminished adaptive capacity under stress as well as degradation of motor functioning. Therefore, sway complexity may be a useful tool in identifying early functional decline in FMR1 premutation carriers as well as monitoring progression towards disease onset.

Balance Performance With and Without Visual Information: A Comparison of Elite Players With Chronic Ankle Instability

Introduction: This research was conducted to determine whether professional athletes with Chronic Ankle Instability (CAI) exhibit differences in maintaining balance under conditions of with and without visual information Materials and Methods: Forty-five elite players with CAI were classified into soccer, volleyball, and basketball groups (n=15 each). All participants performed a static single-leg balance test in conditions wherein visual information was provided and withheld. Also, their center of pressure (CoP) oscillation parameters was measured. The data were examined through an analysis of variance (ANOVA) and the Tukey test. Results: A significant difference was found between the soccer and volleyball players (P=0.034) in anteroposterior CoP displacement. Furthermore, there was a significant difference between soccer compared with volleyball (P=0.001) and basketball (P=0.02) groups regarding mediolateral sway and sway area (P=0.003 and P=0.03, respectively) when they performed the test with their eyes open. A significant difference occurred between the soccer and volleyball players concerning anteroposterior and mediolateral sway (P=0.002 and P=0.04, respectively) and sway area (P=0.004) when they performed the test with their eyes closed. Conclusion: Given the necessity of maintaining a good balance in sports, volleyball coaches should design practices that reduce players’ reliance on visual information. These practices should strengthen their proprioceptive abilities through an increased challenge to their proprioceptive senses.

Postural Stability and Academic Achievements among Fifth Graders: An Experimental Field Study

Postural stability was previously associated with academic achievements among primary school children, but only little is known on how cognitive-motor processes underlie academic achievements. This research was primarily aimed at investigating cognitive-motor performance (e.g., single vs. dual-task gait) and it correlates with achievements in math and language-arts. Fifth-graders (N = 86) performed several motor tasks while their mediolateral trunk sway was assessed using a Kinect 3D sensor. Achievements in math and language-arts were assess one's comply with motor task demands using standardized tests.

Longitudinal Assessment of Balance and Gait After Concussion and Return to Play in Collegiate Athletes.

In longitudinal studies tracking recovery after concussion, researchers often have not considered the timing of return to play (RTP) as a factor in their designs, which can limit the understanding of how RTP may affect the analysis and resulting conclusions. To evaluate the recovery of balance and gait in concussed athletes using a novel linear mixed-model design that allows an inflection point to account for changes in trend that may occur after RTP. Cohort study. University athletics departments, applied field setting. Twenty-three concussed (5 women, 18 men; age = 20.1 ± 1.3 years) and 25 healthy control (6 women, 19 men; age = 20.9 ± 1.4 years) participants were studied. Participants were referred by their team athletic trainers. Measures consisted of the Balance Error Scoring System (BESS) total score, sway (instrumented root mean square of mediolateral sway), single-task gait speed, gait speed while simultaneously reading a handheld article (dual-task gait speed), dual-task cost of reading on gait speed, and dual-task cost of walking on reading. We observed no significant effects or interactions for the BESS. Instrumented sway was worse in concussed participants, and a change in the recovery trend occurred after RTP. We observed group and time effects and group × time and group × RTP change interactions (P ≤ .046). No initial between-groups differences were found for single-task or dual-task gait. Both groups increased gait speed initially and then leveled off after the average RTP date. We noted time and RTP change effects and positive group × time interactions for both conditions (P ≤ .042) and a group × RTP change interaction for single-task gait speed (P = .005). No significant effects or interactions were present for the dual-task cost of reading on gait speed or the dual-task cost of walking on reading. Changes in the rate of recovery were coincident with the timing of RTP. Although we cannot suggest these changes were a result of the athletes returning to play, these findings demonstrate the need for further research to evaluate the effects of RTP on concussion recovery.

High Postural Sway Is an Independent Risk Factor for Osteoporotic Fractures but Not for Mortality in Elderly Women.

The aim of this prospective cohort study was to investigate the independent effect of postural sway on overall fracture and osteoporotic fracture risk after controlling for other established fracture risk factors. As a secondary outcome, mortality was also investigated. The study sample is a stratified random sample of 1568 women born between 1932 and 1941, residing in Kuopio province, eastern Finland. Fracture data were obtained through study questionnaires and verified through hospital records. Mortality data were verified through the National Registry. Using static posturography, postural sway was recorded for 1568 women at the fifth year of follow-up in 1994 through 1997. Mediolateral (ML), anteroposterior (AP), and total sway parameters were used for analysis. Mean follow-up time for any fractures, osteoporotic fractures, and mortality was 10.6, 11.4, and 17.5 years, respectively. After adjustment, subjects in the highest quartile of ML sway (HR, 2.0; 95% CI, 1.5 to 2.8) and total sway (HR, 1.6; 95% CI, 1.2 to 2.2) had a higher risk for any fracture. Osteoporotic fracture risk was also higher in the fourth quartile of ML sway (HR, 1.9; 95% CI, 1.1 to 3.0) and total sway (HR, 1.7; 95% CI, 1.0 to 2.8). The models were adjusted for fracture risk assessment tool risk factors and leg-extension strength. Further, women having both lowest bone density and highest postural sway were at 4.9 (95% CI, 2.6 to 9.5) times higher risk of overall fracture and 11.8 (95% CI, 2.7 to 51.3) times higher risk for osteoporotic fracture in comparison with subjects having highest bone density and lowest postural sway. The association between postural sway and mortality was not significant after adjustment. In conclusion, high postural sway is an independent risk factor for any fractures as well as for osteoporotic fractures. A combination of low bone density and high postural sway poses even higher fracture risk than either factor alone. Postural sway does not predict mortality independently. © 2019 American Society for Bone and Mineral Research.

Complexity of Center of Pressure in Postural Control for Children With Autism Spectrum Disorders Was Partially Compromised.

The purpose of this study was to compare the complexity of postural control between children with autism spectrum disorder (ASD) and typical developing children during altered visual and somatosensory conditions using the multiscale entropy. Eleven children with ASD and 11 typical developing children were tested during quiet standing under 4 conditions: (1)eyes open and standing on a stable surface, (2)eyes open and standing on a compliant surface, (3)eyes closed and standing on a stable surface, and (4)eyes closed and standing on a compliant surface. The center of pressure data were collected, and multiscale entropy and sway area of center of pressure were calculated. The ASD group exhibited lower complexity in mediolateral sway compared with typical developing children with a large effect size (partial η2 = .21). However, based on the different postural control modes, the anteroposterior sway complexity did not demonstrate a similar decrease for children with ASD. The altered visual or somatosensory conditions alone did not significantly affect the postural sway complexity. The authors concluded that the complexity of postural control for children with ASD was partially compromised. Reduced mediolateral sway complexity could potentially increase the risks of fall.

Postural sway, falls, and self-reported neuropathy in aging female cancer survivors

BackgroundFalls are a major public health concern in older adults, and the proportion of older adults that has been diagnosed with cancer is growing. Yet, while falls, peripheral neuropathy, and postural instability are more common in aging cancer survivors, it is unclear how these factors interact. Research questionOur objective was to examine how components of sway related to self-reported neuropathy and falls. MethodsPostural sway during static stance was recorded with an inertial sensor (APDM Opal), placed on the lumbar spine region in 434 older female cancer survivors (mean age 63) and 49 healthy older female control subjects (mean age 63). Measures of sway were resolved into principal components that were compared between women with and women without self-reported falls in the previous 6 months and between those with and without self-reported symptoms of peripheral neuropathy. ResultsCancer survivors had worse sway than healthy control subjects in components related to sway magnitude and mediolateral frequency of sway, but no difference in the component related to resultant / AP sway jerk and frequency. Cancer survivors who reported neuropathy were more likely to have higher resultant / AP sway frequencies and jerk than asymptomatic survivors, while survivors who reported a fall were more likely to have lower frequencies of mediolateral sway than non-fallers. Falls were more strongly associated with mediolateral sway in survivors with more severe neuropathy; whereas falls were more strongly associated with resultant / AP sway frequency in survivors with less severe neuropathy SignificancePostural stability, falls, and neuropathy have complex interactions that can vary across components of postural sway. While the frequency of mediolateral sway was associated with falls across our entire cohort, neuropathy influenced the associations between specific characteristics of sway and falls, which may have implications for fall prevention interventions.

Postural sway changes during static standing with concurrent task in children with traumatic brain injury.

Objectives:To investigate the effects of concurrent tasks (motor and cognitive) on postural control performance in children with traumatic brain injury (TBI) compared to typically developing (TD) control subjects.Methods:Sixteen children with TBI (aged 11.63±1.89 years) and 22 TD controls (aged 11.41±2.24 years) participated in this case-control study. This study was conducted between May 2016 and March 2017. Each child performed static standing under 3 different conditions: single, concurrent motor, and concurrent cognitive task. Postural control performance measure includes sway area, anterior-posterior (AP) sway velocity, medio-lateral (ML) sway velocity, AP sway distance and ML sway distance as measured using the APDM® Mobility Lab (Oregon, Portland). A repeated-measure analysis of variance was used to analyse the data.Results:We found that children with TBI showed significantly more deterioration in postural control performance than TD children (p<0.05). Both concurrent tasks (motor and cognitive) significantly decreased postural control performance in both groups with more pronounced changes in children with TBI than that of the TD controls.Conclusion:The results demonstrated that, performing concurrent tasks (motor and cognitive) during upright standing resulted in deterioration of postural control performance. The existence of cognitive and balance impairment in children with TBI will possibly cause concurrent tasks to be more complex and demands greater attention compared to single task.