Foam pads properties and their effects on posturography in participants of different weight

Screening People on Standing Balance with Romberg Testing and Walking Balance with Tandem Walking

The goal of this protocol is to inform readers about the exact procedures to use to perform two screening tests for vestibular disorders: tandem walking (TW) with eyes closed, also known as heel-toe walking, and the Clinical Test of Sensory Integration and Balance (CTSIB), which is also known as the modified Romberg. The study describes the steps for performing each test and each of the three CTSIB subtests so that the reader will be able to replicate the test conditions for use in the clinic, in the clinical laboratory, or in any other situation needing valid and reliable screening for balance skill which might be affected by changes in vestibular system function. The procedures detailed here can be easily administered and take less than 1 min per trial. References to published papers with normative data are provided. The representative results section includes examples of data collected with these screening tests.

Intermuscular coherence of plantar and dorsiflexor muscles in older adults with Parkinson's disease and age-matched controls during bipedal and unipedal stance

Introduction

Postural instability increases with age and is exacerbated in neurological disorders such as Parkinson's disease (PD). Reducing the base of support from bipedal to unipedal stance increases center of pressure (CoP) parameters and intermuscular coherence in lower-leg muscles of healthy older adults. To further develop an understanding of postural control in an altered state of neurological impairment, we explored intermuscular coherence in lower-leg muscles and CoP displacement in older adults with PD.

Methods

This study measured surface EMG from the medial (MG) and lateral (LG) gastrocnemii, soleus (SOL), and tibialis anterior (TA), and examined EMG amplitude and intermuscular coherence during bipedal and unipedal stance on a force plate with firm (no foam) and compliant (standing on foam) surface conditions in nine older adults with PD (70±5 years, 6 females) and 8 age-matched non-Parkinsonian older adults (5 females). Intermuscular coherence was analyzed between agonist-agonist and agonist-antagonist muscle pairs in the alpha (8-13 Hz) and beta (15-35 Hz) frequency bands.

Results

CoP parameters increased from bipedal to unipedal stance in both groups (p < 0.01), but did not increase from the firm to compliant surface condition (p > 0.05). During unipedal stance, CoP path length was shorter in older adults with PD (2027.9 ± 1074.1 mm) compared to controls (3128.5 ± 1198.7 mm) (p < 0.01). Alpha and beta agonist-agonist and agonist-antagonist coherence increased by 28% from bipedal to unipedal stance (p > 0.05), but did not differ between older adults with PD (0.09 ± 0.07) and controls (0.08 ± 0.05) (p > 0.05). The older adults with PD also had greater normalized EMG amplitude of the LG (63.5 ± 31.7%) and TA (60.6 ± 38.4%) during the balance tasks (p > 0.05) than the non-Parkinsonian counterparts.

Discussion

Older adults with PD had shorter path lengths during unipedal stance and required greater muscle activation than older adults without PD to perform the tasks, but intermuscular coherence did not differ between the groups. This may be attributable to their early disease stage and high motor function.

Vertical ground reaction force oscillation during standing on hard and compliant surfaces: The “postural rhythm”

When a person stands upright quietly, the position of the Centre of Mass (CoM), the vertical force acting on the ground and the geometrical configuration of body segments is accurately controlled around to the direction of gravity by multiple feedback mechanisms and by integrative brain centres that coordinate multi-joint movements. This is not always easy and the postural muscles continuously produce appropriate torques, recorded as ground reaction force by a force platform. We studied 23 young adults during a 90 s period, standing at ease on a hard (Solid) and on a compliant support (Foam) with eyes open (EO) and with eyes closed (EC), focusing on the vertical component of the ground reaction force (VGRF). Analysis of VGRF time series gave the amplitude of their rhythmic oscillations (the root mean square, RMS) and of their frequency spectrum. Sway Area and Path Length of the Centre of Pressure (CoP) were also calculated. VGRF RMS (as well as CoP sway measures) increased in the order EO Solid ≈ EC Solid < EO Foam < EC Foam. The VGRF frequency spectra featured prevailing frequencies around 4–5 Hz under all tested conditions, slightly higher on Solid than Foam support. Around that value, the VGRF frequencies varied in a larger range on hard than on compliant support. Sway Area and Path Length were inversely related to the prevailing VGRF frequency. Vision compared to no-vision decreased Sway Area and Path Length and VGRF RMS on Foam support. However, no significant effect of vision was found on VGRF mean frequency for either base of support condition. A description of the VGRF, at the interface between balance control mechanisms and sway of the CoP, can contribute information on how upright balance is maintained. Analysis of the frequency pattern of VGRF oscillations and its role in the maintenance of upright stance should complement the traditional measures of CoP excursions in the horizontal plane.

Active Videogame Training Combined with Conventional Therapy Alters Body Oscillation in Children with Cerebral Palsy: A Randomized Controlled Trial

Objective: Assess the effect of nonimmersive virtual reality (VR) training as complementary rehabilitation on body oscillation in children with cerebral palsy (CP) while standing on different bases of support and surfaces. Materials and Methods: Twenty-three children with unilateral CP randomly allocated to an intervention group (IG, n = 12) or control group (CG, n = 11). The IG underwent two weekly 50-minute sessions of VR training over 8 weeks, associated with conventional therapy, while the CG was submitted to two 45-minute sessions of conventional neurodevelopmental-based physiotherapy a week over the same time period. Participants were evaluated on a force platform under control conditions (CCs) (rigid surface, feet parallel); semitandem stance; flexible surface (FS) with feet parallel; and flexible surface in a semitandem (FSST) stance. The effect of the group and time factors on the center of pressure oscillation variables was analyzed by repeated-measures analysis of variance (ANOVA), with significance set at 0.05. Results: The main effect observed was for time on the FS, with a decline in the amplitude of mediolateral (ML Amp) (P = 0.01) and mediolateral root mean square (P = 0.01) after intervention. In the IG, ML Amp also declined after intervention under CCs (P = 0.02) and total velocity increased for FSST (P = 0.04). The percentage change was significant only in the IG. Conclusion: VR training as complementary rehabilitation can help improve body oscillation in children with CP and mild functional impairment. Nonimmersive VR can be considered a complementary tool for the physical rehabilitation of children with CP. This study was registered with the Brazilian Clinical Trials Registry (RBR-3zty4w).

Visual Predictors of Postural Sway in Older Adults

Purpose

Accurate perception of body position relative to the environment through visual cues provides sensory input to the control of postural stability. This study explored which vision measures are most important for control of postural sway in older adults with a range of visual characteristics.

Methods

Participants included 421 older adults (mean age = 72.6 ± 6.1), 220 with vision impairment associated with a range of eye diseases and 201 with normal vision. Participants completed a series of vision, cognitive, and physical function tests. Postural sway was measured using an electronic forceplate (HUR Labs) on a foam surface with eyes open. Linear regression analysis identified the strongest visual predictors of postural sway, controlling for potential confounding factors, including cognitive and physical function.

Results

In univariate regression models, unadjusted and adjusted for age, all of the vision tests were significantly associated with postural sway (P < 0.05), with the strongest predictor being visual motion sensitivity (standardized regression coefficient, β = 0.340; age-adjusted β = 0.253). In multiple regression models, motion sensitivity (β = 0.187), integrated binocular visual fields (β = -0.109), and age (β = 0.234) were the only significant visual predictors of sway, adjusted for confounding factors, explaining 23% of the variance in postural sway.

Conclusions

Of the vision tests, visual motion perception and binocular visual fields were most strongly associated with postural stability in older adults with and without vision impairment.

Translational Relevance

Findings provide insight into the visual contributions to postural stability in older adults and have implications for falls risk assessment.

Screening for balance in children and adults in a community science education setting: Normative data, influence of age, sex, and body mass index, and feasibility

BACKGROUND

Screening standing and walking balance is useful for people suspected of having vestibular disorders, a variety of neurologic and musculoskeletal disorders, and for screening astronauts returning after exposure to microgravity. Visitors to a community science education center children and adults, aged 4 to 85, were tested on tandem walking with eyes closed and the modified Romberg test on compliant foam. They were then asked about their experience participating in research, many people for the first time.

METHODS

Subjects performed 10 steps of tandem walking with eyes closed, and three trials of the modified Romberg, or Clinical Test of Sensory Integration and Balance, with eyes closed, standing on compliant memory foam, with a) head still, b) head shaking in yaw, and c) head nodding in pitch. Afterward, staff queried subjects about the experience of participating in science.

RESULTS

Age-related changes across the life span occurred in both sets of tests. Therefore, look-up tables by age are provided. Body mass index significantly affected tandem walking. Some sex differences were found. The tests were easy to administer in a community setting. Most participants enjoyed the experience and reported that they learned about the process of scientific research.

DISCUSSION

These data support and extend the evidence for age-related changes in balance performance across the lifespan and for an influence of body mass index on some balance skills. Clinicians and sports educators should be cognizant of these differences when they use these tests for screening. The community science education environment provided a useful laboratory in which to collect valid and reliable data, while simultaneously educating participants about the process of science.

Can the Clinical Test of Sensory Integration and Balance Predict Performance in Perturbed Walking

Human balance control is a critical prerequisite to nearly all activities, and human falls are a major health concern. The most robust way to assess reactive balance is to apply external perturbations. Perturbations are typically delivered with destabilizing motorized surfaces, external forces, visual motion, or neural stimulation. However, most devices that perturb walking in research settings are not likely to see wide clinical use due to cost, space, and time constraints. In contrast, there are low-cost destabilizing clinical tests that might require similar neural control mechanisms as walking. The present study examines and compares frontal plane balance responses with a research-based surface perturbation walking device to balance responses in a clinical standing balance assessment. We found that correlations between these walking and standing tests varied widely depending on the conditions compared. Correlations between standing and walking balance were highest when 1) a perturbation was present in walking tests, 2) subjects walked slowly, and 3) the standing tests were on foam as opposed to firm surface.Clinical Relevance- This study helps to clarify the relationship between standing and walking balance. We use the clinical test of sensory integration in standing balance and a perturbation treadmill device to measure walking balance.

The effects of mechanical noise bandwidth on balance across flat and compliant surfaces

Although the application of sub-sensory mechanical noise to the soles of the feet has been shown to enhance balance, there has been no study on how the bandwidth of the noise affects balance. Here, we report a single-blind randomized controlled study on the effects of a narrow and wide bandwidth mechanical noise on healthy young subjects’ sway during quiet standing on firm and compliant surfaces. For the firm surface, there was no improvement in balance for both bandwidths—this may be because the young subjects could already balance near-optimally or optimally on the surface by themselves. For the compliant surface, balance improved with the introduction of wide but not narrow bandwidth noise, and balance is improved for wide compared to narrow bandwidth noise. This could be explained using a simple model, which suggests that adding noise to a sub-threshold pressure stimulus results in markedly different frequency of nerve impulse transmitted to the brain for the narrow and wide bandwidth noise—the frequency is negligible for the former but significantly higher for the latter. Our results suggest that if a person’s standing balance is not optimal (for example, due to aging), it could be improved by applying a wide bandwidth noise to the feet.

The impact of x-ray incident angle on indirect fluoroscopy skin dose estimation

Indirect dosimetry to calculate peak skin dose (PSD) is generally based on reference air kerma or kerma-area-product, with effects of table attenuation, inverse square law and backscatter factor applied. When the incident x-ray beam angle changes, these factors would change as well. The purpose of this study is to identify the impact of incident x-ray beam angle on the accuracy of indirect PSD calculation and develop a correction method. Monte Carlo simulation was conducted to assist analytical equation derivation and to validate the developed analytical method. Direct PSD measurements were performed a Siemens Artis Zee biplane fluoroscopy and a GE OEC C-Arm at different angles to validate the proposed correction method and its independence of fluoroscopy systems. Compared with MC simulated PSD, the derived analytical equation successfully predicts these PSD changes for incident angles of 0, 15, 30 and 40 degrees, with the residual error magnitude of 0.3%–3.1% corresponding to different SSDs. The agreement between calculated PSD also agrees well with direct measurement.

The effect of the type of foam pad used in the modified Clinical Test of Sensory Interaction and Balance (mCTSIB) on the accuracy in identifying older adults with fall history

Background

The type of foam pad used in the modified Clinical Test of Sensory Interaction and Balance (mCTSIB) influences the accuracy with which elderly fallers are identified. Two types of foam are commonly used in practice: Airex and Neurocom foam.

Objective

The aim of this study was to assess the accuracy with which elderly fallers can be identified when the Airex foam and Neurocom foam are used in the mCTSIB.

Methods

One hundred eighty-four elderly participants with a mean age of 69 years were classified into faller and nonfaller groups based on their 12-month fall history. Balance stability was measured under four conditions of the mCTSIB for 120 s each: standing on a floor or a foam pad with their eyes open or eyes closed. The time needed to maintain stability was measured by a stopwatch, and postural sway characteristics were measured using an acceleration-based system. Comparisons between groups were performed by two-way mixed ANOVA. The accuracy of differentiating elderly fallers from nonfallers with different foam types was evaluated using receiver operating characteristic curve (ROC) analysis. The time to maintain stability under four conditions of the mCTSIB (composite score) and under two conditions on the foam (foam score) were used for the ROC analysis.

Results

The results showed that the nonfallers required more time to maintain stability and had a smaller sway area than the fallers ( p < 0 . 001 ). The foam led to a larger difference between groups, suggesting the use of foam in examining the risk of falls. The Airex and the Neurocom foam pads led to a large area under the curve (0.93 to 0.95) in identifying elderly fallers and nonfallers when the composite and foam scores were used. A cutoff score of 447/480 s for the composite score and 223/240 s for the foam score yielded a posttest accuracy of 88% to 89%, with a sensitivity of 0.80-0.92 and specificity of 0.88-0.95.

Conclusion

In conclusion, Airex and Neurocom foam can be used interchangeably with guidance in the mCTSIB, as they led to the accurate identification of elderly fallers among older persons who could walk and live independently in the community.

Differences in Responses on the Modified Clinical Test of Sensory Interaction and Balance on Medium Firm and Medium Density Foam in Healthy Controls and Patients with Vestibular Disorders

Purpose

To determine whether foam density affects modified Romberg balance test performance.

Materials and Methods

Controls and patients with vestibular disorders performed Romberg tests on medium and medium firm foam, with their eyes closed and the head still and moving in yaw and pitch. The trial duration and number of head movements were measured.

Results

Subjects aged >60 years performed longer and with more head movements on medium firm foam than on medium foam. Older controls did not differ between medium firm and medium foam. Older patients had higher scores on head-still and head-yaw trials on medium firm foam versus medium foam but pitch trials did not differ. Females, controls, and patients had longer trial durations and more head movements on medium firm foam than on medium density foam; male controls did not differ by foam density. Male patients differed in yaw trials.

Conclusion

Foam density affects scores. Clinical decision-making may be adversely affected if the clinician uses foam of a density that is not the same as that of the foam that was used in the studies that developed descriptive statistics, sensitivity, and specificity.

Impact of Somatosensory Input Deficiency on Subjective Visual Vertical Perception in Children With Reading Disorders

Purpose: Preliminary evidence indicated that children with a reading disorder (RD) may have deviance in their ability to perform high demanding cognitive tasks, such as reading, depending on somatosensory inputs. Until now, only anecdotical reports suggested that improving somatosensory inputs may influence their ability to maintain a stable perception of the visual world despite continuous movements of our eyes, head, and body. Here, we investigated whether changes in upright perception, the subjective visual vertical (SVV), were modulated by somatosensory inputs in a group of children with RD. Method: The SVV task was used under two distinct conditions, i.e., with or without somatosensory inputs from the foot. We enrolled a group of 20 children with reading disorders and 20 sex-, age-, IQ- matched children with neurotypical development. Results: Responses to the SVV task were found to be significantly less accurate in children with RD than in children with neurotypical development (p < 0.001). In the latter, SVV response did not depend on somatosensory inputs from the foot. In contrast, in children with RD somatosensory inputs, either improved or worsen their SVV depending on the tilt direction (p < 0.01). Conclusion: Our results suggested that SVV responses in children with RD could be related to an immaturity for heteromodal sensory integration, including somatosensory inputs.

Exercise using a foam bead bag improves balance and lower extremity strength in older adults

Background/Aims

Balance training using unstable support surfaces is widely used in clinics and research and can reduce the risk of falls in older people. This study aimed to investigate the effect of an exercise programme using a foam bead bag on older adults' ability to balance and the strength of their lower extremities and compare the effect with no exercise and foam pad exercise using the same programme.

Methods

A total of 24 older adults were allocated into one of three groups: control (n=8), foam pad exercise (n=8) and foam bead bag exercise (n=8). The foam pad exercise and foam bead bag exercise groups carried out a programme consisting of 30 minutes of exercise performed twice a week for 5 weeks. The control group did not participate in an exercise programme. Participants' balance abilities were measured using the Fullerton Advanced Balance Scale, the Timed Up and Go Test and the Single-Leg Stance Test. The strength of their lower extremities was measured using the 30-second sit-to-stand test.

Results

The Fullerton Advanced Balance scale and 30-second sit-to-stand scores significantly improved in the foam pad exercise and foam bead bag exercise groups. Both of these groups also demonstrated significant improvements in Timed Up and Go tests. The amount of time that participants were able to stand on one leg while unassisted significantly increased in the foam bead bag group only. No significant differences were found in balance ability or lower extremity strength in the control group.

Conclusions

A foam bead bag is a suitable alternative to a foam pad when performing exercises to improve balance and strength of the lower extremities in older adults.

Normative Performance on the Balance Error Scoring System by Youth, High School, and Collegiate Athletes

CONTEXT

  Annually, more than 1 million youth athletes in the United States receive or are suspected of receiving a concussion. The Balance Error Scoring System (BESS) is the most commonly used clinical balance evaluation designed to provide a better understanding of the motor-control processes of individuals with concussion. Despite the widespread use of the BESS, a fundamental gap exists in applying this tool to young athletes, as normative values are lacking for this population.

OBJECTIVE

  To determine age- and sex-specific normative values for the BESS in youth, high school, and collegiate athletes.

DESIGN

  Cross-sectional study.

SETTING

  Local youth sport organizations, high schools, and colleges.

PATIENTS OR OTHER PARTICIPANTS

  Student-athletes (N = 6762) completed preseason baseline concussion testing as part of a comprehensive concussion-management program. Groups were youth males aged 5 to 13 years (n = 360), high school males aged 14 to 18 years (n = 3743), collegiate males aged 19 to 23 years (n = 497), youth females aged 5 to 13 years (n = 246), high school females aged 14 to 18 years (n = 1673), and collegiate females aged 19 to 23 years (n = 243).

MAIN OUTCOME MEASURE(S)

  Errors according to the BESS specifications.

RESULTS

  Performance on the BESS was worse ( P < .01) in youth athletes than in high school and collegiate athletes. In the youth and high school cohorts, females exhibited better scores than males ( P < .05). Sex was not a factor for collegiate athletes. Data from the youth cohort were further subdivided into 4-year bins to evaluate potential motor-development differences. The error count was highest for 5- to 9-year-old males and decreased with age.

CONCLUSIONS

  Performance on the BESS depended on sex and age, particularly in youth athletes. These sex- and age-specific normative values provide a reference to facilitate and unify clinical decision making across multiple providers caring for youth athletes with concussions.

Influence of both cutaneous input from the foot soles and visual information on the control of postural stability in dyslexic children

Dyslexic children show impaired in postural stability. The aim of our study was to test the influence of foot soles and visual information on the postural control of dyslexic children, compared to non-dyslexic children. Postural stability was evaluated with TechnoConcept^® platform in twenty-four dyslexic children (mean age: 9.3±0.29years) and in twenty-four non-dyslexic children, gender- and age-matched, in two postural conditions (with and without foam: a 4-mm foam was put under their feet or not) and in two visual conditions (eyes open and eyes closed). We measured the surface area, the length and the mean velocity of the center of pressure (CoP). Moreover, we calculated the Romberg Quotient (RQ). Our results showed that the surface area, length and mean velocity of the CoP were significantly greater in the dyslexic children compared to the non-dyslexic children, particularly with foam and eyes closed. Furthermore, the RQ was significantly smaller in the dyslexic children and significantly greater without foam than with foam. All these findings suggest that dyslexic children are not able to compensate with other available inputs when sensorial inputs are less informative (with foam, or eyes closed), which results in poor postural stability. We suggest that the impairment of the cerebellar integration of all the sensorial inputs is responsible for the postural deficits observed in dyslexic children.

Influence of the Plantar Cutaneous Information in Postural Regulation Depending on the Age and the Physical Activity Status

The aim was to compare the balance control adaptation to different supporting surfaces depending on the age and the physical activity status. The balance control of two groups of young (n = 17) and old (n = 17) participants who practiced regular physical activity (active groups) and two groups of young (n = 17) and old (n = 17) participants who did not practice physical activity (non-active groups) was compared on a firm surface and on a foam surface. The parameters of the center of foot pressure (COP) displacement were compared between the groups. The two older groups were more disturbed than the two younger groups when they stood on a foam surface and there was no difference between active and non-active groups. This result may be linked to the structural and functional involutions of the plantar cutaneous sole and foot that occur with age advancement. The participants' physical activity practice might be not specific enough to generate a more efficient postural adaption to the foam condition for the active groups than the non-active groups within their respective age groups.

Comparisons of the effects of a foam pad, mung bean bag, and plastic bead bag on postural stability disturbance in healthy young adults

[Purpose] The aim of the present study was to compare the effects of unstable support surfaces, i.e. foam pad, mung bean bag, and plastic bead bag, on postural stability disturbance. [Subjects and Methods] Twenty-two healthy young adults (11 male and 11 female; aged 21.09 ± 1.44 years; BMI 20.40 ± 1.40 kg/m²) participated in the study. The Balance Master™ was used to evaluate the limit of stability and the unilateral stance performance. Each participant was assessed while standing on the following surfaces: 1) a firm surface, 2) a foam pad, 3) a mung bean bag, and 4) a plastic bead bag. The order of surfaces was randomly assigned. [Results] The mung bean bag and plastic bead bag showed greater disturbances in limit of stability and unilateral stance than the foam pad. There was no significant difference in postural stability disturbance between the mung bean bag and plastic bead bag. [Conclusion] These results suggested that both the mung bean bag and plastic bead bag could be used as a low-cost tool for balance assessment instead of a foam pad in healthy young adults.