Postural control in children with typical development and children with profound hearing loss

Postural Sway Velocity of Deaf Children with and without Vestibular Dysfunction

BACKGROUND

Sensory information obtained from the visual, somatosensory, and vestibular systems is responsible for regulating postural control, and if damage occurs in one or more of these sensory systems, postural control may be altered.

OBJECTIVE

To evaluate and compare the postural sway velocity between children with normal hearing and with sensorineural hearing loss (SNHL), matched by sex and age group, and to compare the postural sway velocity between children with normal hearing and with SNHL, with and without vestibular dysfunction.

METHODS

Cross-sectional study that evaluated 130 children (65 with normal hearing and 65 with SNHL), of both sexes and aged between 7 and 11 years, from public schools of the city of Caruaru, Pernambuco state, Brazil. The postural sway velocity of the center of pressure (COP) was assessed by a force platform, in two directions, anteroposterior (AP) and mediolateral (ML)), in three positions, namely bipedal support with feet together and parallel (parallel feet (PF)), bipedal support with one foot in front of the other (tandem foot (TF)), and single-leg support (one foot (OF)), evaluated with the eyes open and closed.

RESULTS

Children with SNHL demonstrated greater postural sway velocity compared to children with normal hearing in all the positions evaluated, with significant differences in the AP direction, with the eyes open (PF: p = 0.001; TF: p = 0.000; OF: p = 0.003) and closed (PF: p = 0.050; TF: p = 0.005). The same occurred in the ML direction, with the eyes open (PF: p = 0.001; TF: p = 0.000; OF: p = 0.001) and closed (PF: p = 0.002; TF: p = 0.000). The same occurred in relation to vestibular function, where the children with SNHL with an associated vestibular dysfunction demonstrated greater postural sway velocity compared to children with normal hearing in all the positions evaluated, demonstrating significant differences in the AP direction, with the eyes open (TF: p = 0.001; OF: p = 0.029) and eyes closed (PF: p = 0.036; TF: p = 0.033). The same occurred in the ML direction, with the eyes open (TF: p = 0.000) and with the eyes closed (PF: p = 0.008; TF: p = 0.009).

CONCLUSIONS

Children with SNHL demonstrated greater instability of postural control than children with normal hearing in all the directions assessed. Children with SNHL and an associated vestibular dysfunction demonstrated the greatest instability of postural control in this study.

Body representation drives auditory spatial perception

In contrast to the large body of findings confirming the influence of auditory cues on body perception and movement-related activity, the influence of body representation on spatial hearing remains essentially unexplored. Here, we use a disorientation task to assess whether a change in the body's orientation in space could lead to an illusory shift in the localization of a sound source. While most of the participants were initially able to locate the sound source with great precision, they all made substantial errors in judging the position of the same sound source following the body orientation-altering task. These results demonstrate that a change in body orientation can have a significant impact on the auditory processes underlying sound localization. The illusory errors not only confirm the strong connection between the auditory system and the representation of the body in space but also raise questions about the importance of hearing in determining spatial position.

The Effects of Core Stabilization Exercises on Respiratory Muscle Strength, Respiratory Functions, and Postural Control in Children With Hearing Loss: A Randomized Controlled Trial

OBJECTIVES

To evaluate the effects of core stabilization training on respiratory muscle strength, respiratory functions, and postural control in children with hearing loss.

DESIGN

We conducted a randomized controlled trial at Bezmialem Vakif University, Faculty of Health Sciences, Division of Physiotherapy and Rehabilitation. Thirty children with hearing loss who were diagnosed with prelingual sensorineural hearing loss were randomly allocated to the study (n = 15, 12.20 ± 1.69 years) and control (n = 15, 11.87 ± 2.20 years) groups. Core stabilization training protocol was performed by the study group for 8 weeks, 5 days/week, whereas the control group received no training. The primary outcome measure was respiratory muscle strength. The secondary outcome measures were: spirometry, postural control tests on Biodex Balance System, and Balance Error Scoring System (BESS). Exercise adherence was recorded via a diary for home sessions. Outcomes were assessed at baseline and the end of the 8 weeks.

RESULTS

In the study group, a significant improvement was observed in force vital capacity, peak expiratory flow of the spirometry test, maximum inspiratory pressure/expiratory pressure (MEP) of the respiratory muscle strength test; postural stability test except "anterior/posterior stability index", limits of stability test except "backward" and "forward/right", all parameters of the Modified Clinical Test for Sensory Interaction and Balance (mCTSIB) test except "eyes closed firm surface" of the Biodex Balance System, and total score of BESS. Group × time interaction was found in MEP, "overall" stability index in postural stability test, "overall," "left," and "backward left" of limits of stability test, all parameters of the mCTSIB, and BESS total.

CONCLUSIONS

Core stabilization exercises were effective in improving respiratory muscle strength, spirometry, and postural control in children with hearing loss.

Balance Control in Individuals with Hearing Impairment: A Systematic Review and Meta-Analysis

Comprehensive insights into balance control of individuals with hearing impairment are compared with individuals with hearing. Primary sources were obtained from 7 databases including PubMed, LILACS, SCOPUS, CINAHL, PEDro, CENTRAL, and Web of Science. The search period extended from inception until January 5, 2022. The systematic review included 24 studies and 27 trials, with a total of 2,148 participants. The meta-analysis showed a significant difference in the average balance control between individuals with hearing impairment and individuals with hearing, with individuals with hearing having a favorable advantage (p = 0.001). Additionally, average balance control was found to be in favor of individuals with hearing (p = 0.001) when comparing individuals with hearing impairment who participated in sports. Finally, individuals with hearing impairment who participated in sports demonstrated a significantly higher average difference in balance control (p = 0.001) when compared to sedentary people with hearing impairment. Our meta-analysis results indicate a balance defect in individuals with hearing impairment compared to individuals with hearing. In addition, with increasing age, the balance in individuals with hearing impairment improved. Additionally, the dependence of individuals with hearing impairment on the visual and proprioception systems to maintain balance increased. Finally, there was more dependence on the proprioception than the visual system, while individuals with hearing had stronger average balance control than individuals with hearing impairment who participated in sports, when compared to sedentary people with hearing impairment.

Effects of proprioception and core stability training followed by detraining on balance performance in deaf male students: a three-arm randomized controlled trial

PURPOSE

Children with hearing impairment are unable to speak and may suffer from some physical problems such as weakness in postural performance ability and development. The aim of the current study was to explore the effects of proprioception versus core stability training for an 8-week period followed by a 6-month detraining protocol on the balance performance of deaf students.

MATERIALS AND METHODS

This is a randomized controlled trial design of three groups in blinded evaluators. The study was conducted at the school gym. A total of 30 participants, of male deaf students, were randomized into three groups: (1) one group receiving proprioception training (PT, n = 10), (2), one group receiving core stability training (CST, n = 10) for 8 weeks, and (3), and control group (CON, n = 10). The Balance Error Scoring System (BESS) test and Y-balance test assess static and dynamic balance at pre- and post-training following a 6-month detraining.

RESULTS

Post 8 weeks of training intervention, PT and CST values showed significant improvements in both static (p = 0.001) and dynamic (p = 0.001) balance. Following the 6-month detraining, only the PT group maintained their improvements in both the static and dynamic balance tests (p = 0.348) and the CST group showed decreases in the balance tests (p = 0.034).

CONCLUSIONS

The results indicate that 8 weeks rehabilitation program (PT and CST) is an optimum training modality to enhance balance in deaf students and PT induces more training effects than CST for maintaining training benefits following the detraining. Clinical trial registry number: IRCT20170312033029N2; URL: https://en.irct.ir/trial/25584; Trial Id: 25584; Registration date: 2017-12-08; Study start date; 2017-12-22.

Impaired body-centered sensorimotor transformations in congenitally deaf people

Congenital deafness modifies an individual’s daily interaction with the environment and alters the fundamental perception of the external world. How congenital deafness shapes the interface between the internal and external worlds remains poorly understood. To interact efficiently with the external world, visuospatial representations of external target objects need to be effectively transformed into sensorimotor representations with reference to the body. Here, we tested the hypothesis that egocentric body-centred sensorimotor transformation is impaired in congenital deafness. Consistent with this hypothesis, we found that congenital deafness induced impairments in egocentric judgements, associating the external objects with the internal body. These impairments were due to deficient body-centred sensorimotor transformation per se, rather than the reduced fidelity of the visuospatial representations of the egocentric positions. At the neural level, we first replicated the previously well-documented critical involvement of the frontoparietal network in egocentric processing, in both congenitally deaf participants and hearing controls. However, both the strength of neural activity and the intra-network connectivity within the frontoparietal network alone could not account for egocentric performance variance. Instead, the inter-network connectivity between the task-positive frontoparietal network and the task-negative default-mode network was significantly correlated with egocentric performance: the more cross-talking between them, the worse the egocentric judgement. Accordingly, the impaired egocentric performance in the deaf group was related to increased inter-network connectivity between the frontoparietal network and the default-mode network and decreased intra-network connectivity within the default-mode network. The altered neural network dynamics in congenital deafness were observed for both evoked neural activity during egocentric processing and intrinsic neural activity during rest. Our findings thus not only demonstrate the optimal network configurations between the task-positive and -negative neural networks underlying coherent body-centred sensorimotor transformations but also unravel a critical cause (i.e. impaired body-centred sensorimotor transformation) of a variety of hitherto unexplained difficulties in sensory-guided movements the deaf population experiences in their daily life.

Impact of visual impairment on balance and visual processing functions in students with special educational needs

INTRODUCTION

Vision is critical for children's development. However, prevalence of visual impairment (VI) is high in students with special educational needs (SEN). Other than VI, SEN students are prone to having functional deficits. Whether visual problems relate to these functional deficits is unclear. This study aimed to assess the impact of vision on visual processing functions and balance in SEN students through a community service.

METHODS

Visual acuity (VA) and contrast sensitivity were measured in a total of 104 (aged 14.3±4.3) SEN students as the visual outcomes, followed by retinoscopy. Visual processing function assessment included facial expression recognition by card matching examiner's facial expression matching, and visual orientation recognition. Dynamic balance, by Timed Up and Go test, and static standing balance (postural sway in double-legged standing with feet-together and tandem-stance for open-eye and closed-eye conditions) were assessed. Static balance was presented in terms of the maximal medial-lateral and antero-posterior sways.

RESULTS

Of the 104 students, 62 (59.6%) were classified as visually impaired according to WHO classification of visual impairment based on presenting distance acuity. Ocular problems (e.g. optic nerve anomaly, uncorrected/ under-corrected refractive errors) and neurological anomalies were the major causes of vision loss. VA was positively associated with visual processing functions (all p ≤ 0.01), as SEN students with better vision tended to perform better in visual orientation and facial expression recognition tasks, as well as dynamic balance function (p = 0.04). For the static balance, postural sway and VA showed a positive relationship under open-eye and tandem stance conditions. However, the relationship between postural sway and VA became negative under closed-eye and tandem stance conditions.

CONCLUSION

This study found a high prevalence of SEN students with visual impairment, in which many of them were undetected. Optometric examination is important to improve their visual function to minimize the effect of vision on functional performance. Vision is critical in visual processing as well as playing an important role in maintaining balance in SEN students.

Center of pressure-based postural sway differences on parallel and single leg stance in Olympic deaf basketball and volleyball players

In sports such as basketball and volleyball, loss of balance due to the inability to maintain body stability and lack of postural control adversely affect athletic performance. Deaf athletes appear to struggle with balance and postural stability problems. The purpose of this study was to examine postural sway values in parallel and single leg stance of Olympic deaf basketball and volleyball players and reveal differences between the branches. Twenty-three male athletes from the Turkish national deaf basketball (n=11) and volleyball (n=12) teams participated in the study. After anthropometric measurements, the subjects completed postural sway (PS) tests in parallel/single leg stances with open eyes and closed eyes on a force plate. PS parameters (sway path, velocity, and area) obtained from the device software were used for the statistical analysis. The Mann-Whitney U-test was used to compare differences in PS parameters between basketball and volleyball players, and the alpha value was accepted as 0.05. Volleyball players had significantly better results in parallel stance and dominant leg PS values than basketball players (P<0.05). There was no significant difference between the groups in nondominant leg PS values (P>0.05). We think that proprioceptive and vestibular system enhancing training practices to be performed with stability exercises will be beneficial in terms of both promoting functional stability and interlimb coordination. Trainers and strength coaches should be aware of differences in the postural control mechanism of deaf athletes.

Vestibular status: A missing factor in our understanding of brain reorganization in deaf individuals

The brain of deaf people is definitely not just deaf, and we have to reconsider what we know about the impact of hearing loss on brain development in light of comorbid vestibular impairments.

Early general development and central auditory system maturation in children with cochlear implants - A case series

OBJECTIVES

A cochlear implant (CI) has the potential to improve the functioning of a deaf child in many aspects. Nevertheless, the dynamics of the general development, beyond the typically measured language abilities, directly after CI, is still unknown, especially if a child is implanted early. In this study we present a methodological framework for assessment of different domains of development, as well as the central auditory nervous system (CANS) maturation in infants and toddlers with a CI.

METHODS

Three children with bilateral congenital hearing loss and a unilateral CI, aged below 2.5 years, participated in a longitudinal study. Children were tested at three time points after cochlear implantation using the Polish Children Development Scale (CDS) consisting of a comprehensive battery of tests, as well as recordings of Cortical Auditory Evoked Potentials (CAEP).

RESULTS

All three children revealed gradual improvement in the overall CDS result as well as most of the CDS subscales. After 9 months of CI experience two younger children showed age-appropriate performance. In CAEP measurements a decrease of latency of the P1 component (an established biomarker of cortical auditory maturation) was observed in the same two children, with one achieving normal ranges of P1 latency after 9 months of CI use.

CONCLUSIONS

Our novel methodological framework can be successfully applied in small children with cochlear implants. It contributes to better understanding of the general development in early implanted children. The preliminary results indicate variability in children's performance in various developmental domains and thus the need to monitor the development of each child individually and holistically.

The influence of Pilates exercises on body balance in the standing position of hearing impaired people

PURPOSE

Hearing impairment may affect the body posture maintenance. The aim of the study was to evaluate the effect of modified Pilates exercise program on the body posture maintenance in hearing impaired people.

METHODS

Eighty students (aged 13-24) were enrolled and randomly allocated into two groups: test group (n = 41) which attended an original program based on modified Pilates exercises and control group (n = 39) which attended standard physical education classes. Stabilographic tests were conducted at baseline and after 6-week training program.

RESULTS

Both groups showed improved control of body balance in a standing position manifested in reductions of the length of path, surface area, and speed of deflection. Modified Pilates program was significantly more effective in improving body balance control in relaxed posture and with feet together than standard physical education classes. The greater efficiency of the modified Pilates program was expressed in a significant improvement in balance control parameters, i.e., path length, surface area, and speed of deflection.

CONCLUSIONS

The modified Pilates program was more effective in improving body balance control in the hearing impaired people than standard physical education classes. Modification of physical activity recommendations for hearing impaired students may be considered; however, further research is required. Implications for Rehabilitation Hearing impairment impacts the mental, social and, physical spheres of life as well as deteriorates equivalent reactions and the way body posture is maintained. In hearing impaired people, control of body balance and muscle coordination is often disturbed, thus more attention should be paid to exercises associated with balance which may improve the ability to learn and develop motor skills. Modified Pilates program was significantly more effective in improving body balance control than standard physical education classes in hearing impaired people.

Dominant deafness-onychodystrophy syndrome caused by an ATP6V1B2 mutation

Our report clarifies the role of ATP6V1B2 in patients with deafness and onycho‐osteodystrophy and confirms that a recurring ATP6V1B2 c.1516C>T [p.(Arg506*)], variant causes dominant deafness–onychodystrophy (DDOD) syndrome.

Postural seated balance in children can be assessed with good reliability

BACKGROUND

Seated postural stability can be measured using Tekscan, CONFORMat. Standing postural stability has gained great clinical and, research value by use of different force platforms with mostly good reliability. No reliability testing or biologic variation assessment has been documented regarding seated balance. This study determines the reliability of the parameters of seated balance in healthy children using the Tekscan CONFORMat equipment.

METHODS

Sixty-six healthy children completed six measurements of seating position the first three with the child seated in a relaxed normal back position and the next three with the child seated in a complete up-right back position. The SAM software calculated five default parameters of balance (area, distance, variability, antero-posterior (AP) excursion and left-right excursion).

RESULTS

Reliability parameters were assessed by one-way analysis of variance intra-class correlation (ICC) proving excellent reliability for relaxed and up-right back position with respect to distance (0.75/0.84) and good reliability with respect to variability (0.61/0.62) and area (0.61/0.60). AP excursion (0.41/0.59) and left-right excursion (0.54/0.24) showed fair to poor reliability.

CONCLUSION

In conclusion, two of the five default parameters of balance used in the Tekscan CONFORMat system are direction-independent parameters and have been found reproducible for measuring seated balance in children. This study can be used as reference for comparisons of seated balance in children with affected seated postural control and for evaluating a clinical treatment effect.

Body Perception and Action Following Deafness

The effect of deafness on sensory abilities has been the topic of extensive investigation over the past decades. These investigations have mostly focused on visual capacities. We are only now starting to investigate how the deaf experience their own bodies and body-related abilities. Indeed, a growing corpus of research suggests that auditory input could play an important role in body-related processing. Deafness could therefore disturb such processes. It has also been suggested that many unexplained daily difficulties experienced by the deaf could be related to deficits in this underexplored field. In the present review, we propose an overview of the current state of knowledge on the effects of deafness on body-related processing.

Postural control assessment in students with normal hearing and sensorineural hearing loss

Introduction

Objective

Methods

Results

Conclusions

Head Position Comparison between Students with Normal Hearing and Students with Sensorineural Hearing Loss

Introduction Head sense position is coordinated by sensory activity of the vestibular system, located in the inner ear. Children with sensorineural hearing loss may show changes in the vestibular system as a result of injury to the inner ear, which can alter the sense of head position in this population.

Aim Analyze the head alignment in students with normal hearing and students with sensorineural hearing loss and compare the data between groups.

Methods This prospective cross-sectional study examined the head alignment of 96 students, 48 with normal hearing and 48 with sensorineural hearing loss, aged between 7 and 18 years. The analysis of head alignment occurred through postural assessment performed according to the criteria proposed by Kendall et al. For data analysis we used the chi-square test or Fisher exact test.

Results The students with hearing loss had a higher occurrence of changes in the alignment of the head than normally hearing students (p < 0.001). Forward head posture was the type of postural change observed most, occurring in greater proportion in children with hearing loss (p < 0.001), followed by the side slope head posture (p < 0.001).

Conclusion Children with sensorineural hearing loss showed more changes in the head posture compared with children with normal hearing.

The effect of interventional proprioceptive training on static balance and gait in deaf children

Children with hearing impairment have balance and motor deficits primarily due to concomitant damage to the vestibular structures. Although early intervention focused on the development of communication skills, investigations of intervention for the amelioration of balance deficits in children with hearing loss have been minimal and inconclusive. Therefore, using an experimental design, the present study investigated the effect of a 12-session exercise balance program based on proprioception training on balance and gait in deaf as compared with hearing schoolchildren. The subjects, 10 deaf and 10 typically developing children were assigned to an experimental and a control group respectively. Taking up the initial differences between the groups through a pretest under different conditions, the participants in the experimental group went through a 12-session intervention program including static and dynamic training with emphasis on proprioceptive system. After this, the participants were tested again. The data obtained was analyzed using repeated measure. A comparison between the control and experimental groups revealed that the intervention program had not significantly increased gait velocity while it had significantly decreased the amount of sway. Thus, it was concluded that an exercise program that enhances somatosensory ability can result in improved balance in deaf children.

Balance assessment in hearing-impaired children

According to the scientific reports the postural stability is inseparably associated with hearing organ's correct functioning. The aim of the study was to evaluate the degree of disorders occurring in balance reactions in this group of children with profound hearing loss compared to their healthy peers. The study worked with a total of 228 children, including 65 who are deaf (DCH) and 163 subjects without any hearing deficits (CON) in the control group. Stabilometric measurements were performed with the use of a force distribution platform. The results indicate statistically significant differences in terms of one parameter (the total path length) recorded in the test with the eyes open and a whole range of parameters recorded when the subjects had their eyes closed (the width, height, and area of the ellipse, the total path length, and the horizontal and vertical sway). The study results showed better values of the static balance parameters in deaf children as compared to their peers without hearing disorders and the differences were particularly evident in the test with the subject's eyes closed. The results suggest significantly better processing of sensory stimuli in postural reactions particularly from propioception, and to a lesser extent, from the vision system observed in the subjects as compared to their peers in the control group.