Evi Verbecque

Psychometric properties of functional balance tests in children: a literature review

Identifying balance problems are the first step towards monitoring and rehabilitation. Therefore, this paper aims to make an overview of the psychometric properties of the functional balance tests available for children.

Age-related changes in postural sway in preschoolers.

OBJECTIVES The present study aimed to investigate age-related differences of postural sway in 3- to 6-year-old typically developing children in different sensory conditions and subsequently to provide reference values for global descriptive sway parameters in preschoolers. METHODS Ninety-six typically developing children, between 3 and 5 years of age, participated in this cross-sectional study. Postural sway was measured for 40s in four conditions (eyes open/eyes closed on stable ground/foam) by using a force plate. Global descriptive sway parameters were calculated and analysed using a 2 × 2 × 3 (surface × vision × age group) MANOVA (p<0.05) in the children that were able to complete the task (40s). RESULTS When sensory information was altered, a significantly smaller number of 3- and 4-year-olds was able to complete the task. Significant main effects of vision (p<0.05), surface (p<0.001) and an interaction effect between vision and surface (p<0.05) on all postural sway parameters were found. A significant main effect of age was found for antero-posterior amplitude (p=0.047), medio-lateral root mean square (p=0.012) and area (p=0.009) between 3- and 5-year-olds and 4- and 5-year-olds. No interaction effects (surface × vision × age group) were found. CONCLUSIONS During natural stance, the amount of postural sway distinguishes 5-year-olds from 3- and 4-year-olds, highlighting the need for age-specific reference values for specific balance-related sway parameters (e.g. RMS_ml). Regarding test conditions with altered sensory input, a larger number of 5-year-old children are able to perform more difficult tasks. Nevertheless, if 3- or 4-year-olds are able to perform the more difficult tasks, their performance can be compared to the older children.

Vestibular (dys)function in children with sensorineural hearing loss: a systematic review

Abstract Objective: The objective of this study is to provide an overview of the prevalence of vestibular dysfunction in children with SNHL classified according to the applied test and its corresponding sensitivity and specificity. Design: Data were gathered using a systematic search query including reference screening. Study sample: Pubmed, Web of Science and Embase were searched. Strategy and reporting of this review was based on the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Methodological quality was assessed with the COnsensus‐based Standards for the selection of health Measurement INstruments (COSMIN) checklist. Results: All studies, regardless the applied vestibular test, showed that vestibular function differs significantly between children with hearing loss and normal hearing (p < 0.05). Compared with caloric testing, the sensitivity of the Rotational Chair Test (RCT) varies between 61 and 80% and specificity between 21 and 80%, whereas this was, respectively, 71–100% and 30–100% for collic Vestibular Evoked Myogenic Potentials (cVEMP). Compared with RCT, the sensitivity was 88–100% and the specificity was 69–100% for the Dynamic Visual Acuity test, respectively, 67–100% and 71–100% for the (video) Head Impulse Test and 83% and 86% for the ocular VEMP. Conclusions: Currently, due to methodological shortcoming, evidence on sensitivity and specificity of vestibular tests is unknown to moderate. Future research should focus on adequate sample sizes (subgroups >30).

A Modified Version of the Timed Up and Go Test for Children Who Are Preschoolers.

Purpose: This study investigated factors predicting the Timed Up and Go (TUG) test in children who are preschoolers, using a modified protocol of the TUG. Method: This was a cross-sectional study of children 3 to 5 years old (n = 192). Regression analysis identified predictive factors for TUG performances. Differences in mean values (standard deviation) were calculated for each age group. Results: The results of 172 children were analyzed. Age and ethnicity were predictive of TUG performance (R2 = 0.280). Children who are preschoolers with Flemish ethnicity need less time to perform the TUG than their peers with another ethnicity (P < .05), but this difference is not significant for the age groups. The TUG performance differs significantly among all age groups (P < .05). Conclusions: A modified protocol for the TUG, which is sensitive to age-related changes in dynamic balance control, is proposed for children who are preschoolers.

Standing balance in preschoolers using nonlinear dynamics and sway density curve analysis

The aim of the present study was to investigate how age and sensory deprivation affect the temporal organization of CoP sway variability and the postural corrective commands during standing balance in typically developing preschoolers. A sample of 57 children aged 3-5 years participated in the study. Structural stabilometric descriptors of sample entropy (SEn), detrended fluctuation analysis (DFA), and sway density curve (SDC) analysis were employed to assess features of center of pressure sway. A force platform was used to collect center of pressure data during standing balance over 40 s in four conditions: standing on rigid and foam surfaces with eyes open and closed. The main results are as follows: (1) sample entropy decreased and DFA_coefficient increased with age, while the SDC variables remained unaltered among the 3-, 4-, and 5-year-old children; (2) as sensory conditions became more challenging, sample entropy decreased and DFA_coefficient increased, while MT and MD decreased and MD increased; age did not influence the responses to sensorial deprivation. In conclusion, 5-year-old children showed decreased variability of CoP sway during standing balance compared with the younger children, but all children used the same corrective torques to control for perturbations. More challenging sensory deprivation conditions resulted in decreased variability of postural sway, higher amplitudes and more frequent correcting torques for stabilization, but age did not influence these behaviors.

Age-related changes in arm motion during typical gait

BACKGROUND When toddlers learn to walk, they do so with a typical high guard position of the arms. As gait matures, children develop a reciprocal arm swing. So far, there have been no attempts to describe age-related changes of arm movements during walking after this first rapid development. RESEARCH QUESTION The purpose of this study was to investigate age-related changes in arm movement during typical gait. METHODS All participants (n = 102) received gait analysis using a full-body marker set (Plug-in Gait). Participants were divided into five age-groups: young children (G1: n = 20; 3.0-5.9y), children (G2: n = 24; 6.0-9.9y), pubertal children (G3: n = 26; 10.0-13.9y), adolescents (G4: n = 16; 14.0-18.9y) and adults (G5: n = 16; 19.0-35.2y). Age-related changes in arm movements were investigated by comparing continuous joint angular waveforms (spm1d) between all groups, as well as by comparing the mean joint angle and range of motion of the different joints between age-groups. RESULTS The overall shape of movement patterns was comparable across all age groups. Nevertheless, with advancing age, consistency increased. At the shoulder, G1&2 showed a larger mean extension angle compared to older children and adults. The range of shoulder axial rotation was significantly larger in adults compared to all other age groups. In the youngest groups (G1-G2), an increased mean elbow flexion and mean wrist extension angle was found. SIGNIFICANCE Determining an exact age of maturation of arm swing remains difficult as parameter specific adult-like values were not reached at the same age but should not be set before the age of ten to fourteen years for any parameter.

Dynamic Visual Acuity test while walking or running on treadmill: Reliability and normative data

BACKGROUND This study aimed to report normative reference data for a Dynamic Visual Acuity test while walking on treadmill. The protocols suitability was assessed by investigating its test-retest reliability and its validity through the drop-out rate and verification of the frequency of head movements. Furthermore, the influence of age on visual acuity loss (VAL) was determined to reveal the need for age-specific reference data. METHODS Visual acuity was measured in 171 healthy adult participants (age range: 20.0-77.3 years; mean age: 40.1 years) with the head stationary (SVA) and in a dynamic condition (DVA) while walking on treadmill at 3, 4, 6 and 9 km/h. Relative test-retest reliability on SVA and DVA was investigated with intraclass correlation coefficients (ICC). The measurement errors of SVA, DVA and VAL were calculated for absolute reliability. Influence of age on VAL was investigated with regression analysis, followed by an ANOVA to investigate decade-related differences. The drop-out rate during DVA was mapped using a frequency table. Head frequencies were monitored using 3D motion tracking software. RESULTS Strong consistency (ICC ≥ 0.89) was found for SVA and DVA values. Measurement errors for VAL were less than 0.1 logMAR. Younger participants (decade 3-4) showed less VAL at 3 and 4 km/h. The drop-out rate increased with increasing walking speed (0-18.8%), especially in older adults. Although head frequency increased with increasing speed, the dominant frequency ranged around 2 Hz for all walking speeds. CONCLUSION This DVA protocol is reliable and normative data have been established. To facilitate its use in clinical practice, further validation of the protocol in patients with bilateral vestibulopathy is needed.BACKGROUND This study aimed to report normative reference data for a Dynamic Visual Acuity test while walking on treadmill. The protocols suitability was assessed by investigating its test-retest reliability and its validity through the drop-out rate and verification of the frequency of head movements. Furthermore, the influence of age on visual acuity loss (VAL) was determined to reveal the need for age-specific reference data. METHODS Visual acuity was measured in 171 healthy adult participants (age range: 20.0-77.3 years; mean age: 40.1 years) with the head stationary (SVA) and in a dynamic condition (DVA) while walking on treadmill at 3, 4, 6 and 9 km/h. Relative test-retest reliability on SVA and DVA was investigated with intraclass correlation coefficients (ICC). The measurement errors of SVA, DVA and VAL were calculated for absolute reliability. Influence of age on VAL was investigated with regression analysis, followed by an ANOVA to investigate decade-related differences. The drop-out rate during DVA was mapped using a frequency table. Head frequencies were monitored using 3D motion tracking software. RESULTS Strong consistency (ICC ≥ 0.89) was found for SVA and DVA values. Measurement errors for VAL were less than 0.1 logMAR. Younger participants (decade 3-4) showed less VAL at 3 and 4 km/h. The drop-out rate increased with increasing walking speed (0-18.8%), especially in older adults. Although head frequency increased with increasing speed, the dominant frequency ranged around 2 Hz for all walking speeds. CONCLUSION This DVA protocol is reliable and normative data have been established. To facilitate its use in clinical practice, further validation of the protocol in patients with bilateral vestibulopathy is needed.

Developmental changes in spatial margin of stability in typically developing children relate to the mechanics of gait

BACKGROUND Immature balance control is considered an important rate limiter for maturation of gait. The spatial margin of stability (MoS) is a biomechanical measure of dynamic balance control that might provide insights into balance control strategies used by children during the developmental course of gait. RESEARCH HYPOTHESIS We hypothesize there will be an age-dependent decrease in MoS in children with typical development. To understand the mechanics, relations between MoS and spatio-temporal parameters of gait are investigated. METHODS Total body gait analysis of typically developing children (age 1-10, n = 84) were retrospectively selected from available databases. MoS is defined as the minimum distance between the center of pressure and the extrapolated center of mass along the mediolateral axis during the single support phases. RESULTS MoS shows a moderate negative correlation with stride length (rho = -0.510), leg length (rho = -0.440), age (rho = -0.368) and swing duration (rho = -0.350). A weak correlation was observed between MoS and walking speed (rho = -0.243) and step width (rho = 0.285). A stepwise linear regression model showed only one predictor, swing duration, explaining 18% of the variance in MoS. MoS decreases with increasing duration of swing (β = -0.422). This relation is independent of age. SIGNIFICANCE A larger MoS induces a larger lateral divergence of the CoM that could be compensated by a quicker step. Future research should compare the observed strategies in children to those used in adults and in children with altered balance control related to pathology.

Do spatiotemporal parameters and gait variability differ across the lifespan of healthy adults? A systematic review

BACKGROUND Aging is often associated with changes in the musculoskeletal system, peripheral and central nervous system. These age-related changes often result in mobility problems influencing gait performance. Compensatory strategies are used as a way to adapt to these physiological changes. RESEARCH QUESTION The aim of this review is to investigate the differences in spatiotemporal and gait variability measures throughout the healthy adult life. METHODS This systematic review was conducted according to the PRISMA guidelines and registered in the PROSPERO database (no. CRD42017057720). Databases MEDLINE (Pubmed), Web of Science (Web of Knowledge), Cochrane Library and ScienceDirect were systematically searched until March 2018. RESULTS Eighteen of the 3195 original studies met the eligibility criteria and were included in this review. The majority of studies reported spatiotemporal and gait variability measures in adults above the age of 65, followed by the young adult population, information of middle-aged adults is lacking. Spatiotemporal parameters and gait variability measures were extracted from 2112 healthy adults between 18 and 98 years old and, in general, tend to deteriorate with increasing age. Variability measures were only reported in an elderly population and show great variety between studies. SIGNIFICANCE The findings of this review suggest that most spatiotemporal parameters significantly differ across different age groups. Elderly populations show a reduction of preferred walking speed, cadence, step and stride length, all related to a more cautious gait, while gait variability measures remain stable over time. A preliminary framework of normative reference data is provided, enabling insights into the influence of aging on spatiotemporal parameters, however spatiotemporal parameters of middle-aged adults should be investigated more thoroughly.

Gait and its components in typically developing preschoolers

OBJECTIVES To determine whether key spatio-temporal components of gait can be identified in children who are preschoolers. Subsequently the obtained components were correlated to results of functional balance tests to determine which of them are related to balance control. METHODS Thirty-three typically developing children performed gait on treadmill at three speeds (range 2-4.5km/h), the Pediatric Balance Scale (PBS) and the Timed Up and Go test (TUG). Principal component analysis (PCA) with varimax rotation was performed to detect relations between means and variability of step time, -length and -width, walking speed, age, BMI and leg length. Pearson correlation coefficients between the principal components and z-scores of the PBS and TUG were calculated. RESULTS PCA revealed three principal components. The first component, maturation, showed high loadings for mean step length (0.911), age (0.897), walking speed (0.895), leg length (0.874) and step time variability (-0.672) explaining 37.57% of the variance. The second component, variability of gait, loaded with step length variability (0.819) and step width variability (0.818), explaining 18.02% of the variance. The third component, robustness, showed high loadings for mean step time (0.729), BMI (0.668) and mean step width (0.521), explaining 13.89% of the variance. A significant weak correlation was found between robustness and z-scores of the PBS (r=0.230, p=0.005). CONCLUSIONS It seems that the key spatio-temporal component robustness is complementary to functional balance tests, suggesting its relevance in the assessment of balance control in preschoolers.