Static and dynamic postural control in low-vision and normal-vision adults

Deep Learning-Based Obesity Identification System for Young Adults Using Smartphone Inertial Measurements

Obesity recognition in adolescents is a growing concern. This study presents a deep learning-based obesity identification framework that integrates smartphone inertial measurements with deep learning models to address this issue. Utilizing data from accelerometers, gyroscopes, and rotation vectors collected via a mobile health application, we analyzed gait patterns for obesity indicators. Our framework employs three deep learning models: convolutional neural networks (CNNs), long-short-term memory network (LSTM), and a hybrid CNN-LSTM model. Trained on data from 138 subjects, including both normal and obese individuals, and tested on an additional 35 subjects, the hybrid model achieved the highest accuracy of 97%, followed by the LSTM model at 96.31% and the CNN model at 95.81%. Despite the promising outcomes, the study has limitations, such as a small sample and the exclusion of individuals with distorted gait. In future work, we aim to develop more generalized models that accommodate a broader range of gait patterns, including those with medical conditions.

Balance performance of healthy young individuals in real versus matched virtual environments: a systematic scoping review

Background

Due to technological advancements and the development of consumer-oriented head mounted displays (HMDs), virtual reality (VR) is used in studies on balance performance and balance trainability more and more frequently. Yet, it may be assumed that balance performance is affected by the physical characteristics of the HMD (e.g., weight) as well as by the virtual visual environment. Moreover, it has been shown that balance is age-dependent with children and adolescents showing worse performances compared to young adults, which may also affect their balance performance in virtual environments.

Objectives

The present systematic scoping review aims to provide an overview on the current evidence regarding balance performance of healthy, young individuals (6–30 years) in real and matched virtual environments.

Methods

A systematic literature search in the electronic databases PubMed, Web of Science, and SPORTDiscus (from their inception date to February 2024) resulted in 9,554 studies potentially eligible for inclusion. Eligibility criteria were: (i) investigation of healthy, young individuals (6–30 years), (ii) balance assessment in the real and a matched virtual environment, (iii) use of a fully immersive HMD, (iv) reporting of at least one balance parameter. A total of 10 studies met the predefined inclusion criteria and were thus included in this review. All studies were conducted with healthy, young adults (19–30 years).

Results

Five studies assessed static balance, four studies quantified dynamic balance, and one study measured static as well as dynamic balance performance. In healthy young adults, static balance performance was similar with and without VR during simple standing tasks (e.g., two-legged stance), but worse in VR during more challenging tasks (e.g., one-legged stance). Concerning dynamic balance, four out of five studies reported worse performance in VR, while one study did not find differences between visual environments. Most importantly, none of the studies investigating healthy children (6–12 years) and/or adolescents (13–18 years) met the predefined inclusion criteria.

Conclusion

In healthy young adults, balance performance seems to be affected by VR only during challenging static (e.g., one-legged stance) as well as during dynamic balance tasks. The underlying causes remain unclear, but factors such as perceived presence in VR, a shift in sensory organization and/or perceptual distortion may play a role. Of particular importance is the finding that there is a void in the literature on the influence of VR on balance performance of healthy children and adolescents.

The decline in postural balance has a negative impact on the performance of functional tasks in individuals with Parkinson's Disease

INTRODUCTION

An accurate assessment of balance problems is critical for decreasing the risk of falling in patients with Parkinson's Disease (PD). Reliable diagnostic tools such as Computerized Dynamic Posturography (CDP) are not feasible for the clinical setting. Therefore, the present study's aim was to assess the correlation between the clinical Balance Evaluation Systems Test (BESTest) and CDP.

METHODS

20 male older adults with Parkinson's Disease (PD) were included in this study. Participants first executed the Sit-To-Stand (STS), Step/Quick turn (SQT), and Step Up and Over (SUO) tests on a Balance Master® force platform, followed by a clinical balance evaluation using the BESTest.

RESULTS

Four outcomes of the CDP were negatively correlated with one or more BESTest domains or total BESTest score: STS sway velocity was negatively correlated with the anticipatory postural adjustment (p = 0.02) and sensory orientation (p = 0.01) domains. SQT turn time was negatively correlated with biomechanical restriction (for turns to the left, p = 0.01, and right, p = 0.03, respectively), postural response (p = 0.01, p = 0.01), dynamic balance during gait (p = 0.007, p = 0.001), and total score (p = 0.02, p = 0.01). Step over time to the right in SUP was negatively correlated with the limits of the stability domain (p = 0.002) and total BESTest score (p = 0.020). SUO impact index was negatively correlated with the anticipatory postural adjustment domain (p = 0.01).

CONCLUSION

This study shows that several BESTest domains are significantly correlated with CDP outcomes, demonstrating that the BESTest can be used as a more clinically feasible alternative for computerized posturography, without loss of information.

Population-Level Associations Between Visual Impairment and Functional Difficulties in California

PURPOSE

The prevalence of visual impairment is increasing, and there is a need to understand the functional implications. Using the American Community Survey (ACS) data, this study examined the relationship between visual impairment and functional difficulties in California.

METHODS

Using the 2010-2014 and 2015-2019 ACS 5-year estimates from the U.S. Census, data were obtained for visual impairment and functional difficulties including hearing, cognitive, ambulatory, self-care, and independent living difficulties. The prevalence of vision impairment and each functional difficulty was calculated on the Medical Service Study Area (MSSA) level in California. Unadjusted and adjusted linear regression models were performed to estimate the association between visual impairment and each functional difficulty, adjusting for age, sex, race and ethnicity, education level, English-speaking ability, poverty status, health insurance status, and urbanity of residence location.

RESULTS

The prevalence of visual impairment in California was 2.3% (659,502 of 28,794,572) in 2010-2014 and 2.3% (709,353 of 30,231,767) in 2015-2019 among the population ≥ 18 years old. There were statistically significant associations between the prevalence of vision impairment and increased prevalence of all functional difficulties, with the most positive correlation observed with ambulatory difficulty (slope estimate 0.58 ± 0.072 for 2010-2014 and 0.78 ± 0.082 for 2015-2019 for ambulatory difficulty).

CONCLUSIONS

There may be population-level impacts of functional consequences from vision impairment, suggesting the need for neighborhood-level investigation and policy-based interventions to address the burden of vision impairment on the population level.

Modern smartphone usage can negatively impact postural balance while standing on dynamically challenging grounds

BACKGROUND

While several studies have explored the impacts of smartphone usage on postural balance, their tasks are limited to texting or calling, and the studies were performed on rigid ground.

RESEARCH QUESTIONS

METHODS: Sixteen healthy young adults were recruited to perform two smartphone tasks: taking selfies and posting statuses on social media; participants were standing on four different grounds: rigid, foam-based compliant, robot-simulated compliant, and robot-simulated oscillatory grounds. The center-of-pressure (CoP) under each foot was recorded via force plates and the net CoP was calculated. Temporal, spatial, and control aspects of postural balance were analyzed by virtual time-to-contact (VTC), CoP path length (PL) and sway area (SA), and switching rate (SR), respectively. Two-way repeated measures analysis of variance (ANOVA) tests were performed for each dependent variable to compare the mean differences between smartphone tasks and ground conditions and their interaction effect. Paired t-tests with Bonferroni correction were used to determine significant differences in post-hoc analyses.

RESULTS

VTC decreased significantly whereas CoP PL and SA increased significantly during smartphone usage (all p-values <0.001). Interaction effects between task and ground condition (all p-values <0.001) were observed in all measures but SR, implying that the effect of smartphone usage on postural balance can significantly change depending on the ground condition.

SIGNIFICANCE

These results highlight the potential fall risks due to the impact of modern smartphone usage on standing balance. Understanding the effect of smartphone usage on standing balance and the interaction effect with various ground conditions opens the door for potential balance assistive devices and mobile phone applications to minimize falls.

The Effect of Visual Impairment on Postural Stability After Lumbar Spine Fracture: A Case Report and Review of the Literature

The role of vision in maintaining postural stability is crucial, and its loss, whether congenital or acquired, can significantly impact sensory-motor interactions, leading to musculoskeletal abnormalities and defective gait patterns. This case report discusses the complex interplay between visual impairment, post-traumatic kyphosis, and the development of spinal deformity in a 79-year-old blind patient. The patient sustained a simple fall resulting in an L1 compression fracture in 2016. Despite conservative treatment for the fracture, progressive spinal deformity became evident both clinically and radiographically. Further assessments, including evaluation of bone healing, facet arthroplasty, disc degeneration, and canal compromise, were performed. The patient's altered gait and postural abnormalities were indicative of the impact of visual impairment on postural stability. After addressing osteoporosis through endocrinology consultation and medical management, the patient underwent posterior spinal instrumentation and deformity correction, leading to a successful post-operative recovery with a return to baseline functional status. Visual impairment disrupts postural stability by limiting sensory input and prompting compensatory mechanisms, which may increase postural sway and instability. This abnormal gait further contributes to spinal deformities, and the fear of falling can exacerbate postural instability, limiting mobility. Over time, persistent postural imbalance leads to the creation of a state of continual asymmetric stress related to the spinal axis, which can progress to the development of spinal deformities, creating a self-perpetuating cycle.  This case underscores the significance of vision in postural stability and the adverse effects of visual impairment on spinal alignment. The development of spinal deformities in visually impaired individuals, especially in the presence of risk factors like osteoporosis, emphasizes the need for early intervention and postural training to prevent irreversible deformities. Decisions regarding surgical or non-surgical interventions for spinal deformities in visually impaired patients must consider multiple factors, including clinical symptoms, appearance, pain, functional limitations, and social issues. Future research should explore effective interventions for improving postural stability in visually impaired individuals and preventing the development of spinal deformity.

Physical activity and sport practice to improve balance control of visually impaired individuals: a narrative review with future perspectives

Visual disability negatively impacts balance, everyday self-efficacy, and mobility and often leads affected subjects to perceive physical exercise as a burdensome challenge thus discouraging them from practicing. Despite the well-proven benefits of regular physical activity in visually impaired people, especially addressing postural control, there are no specific guidelines and most of the available literature seems to be flawed by critical issues. Given the wide heterogeneity and the multidimensional needs of this population, a more realistic and target-specific perspective is needed in order to properly investigate and promote exercise practice and adherence for balance improvement. On this basis, through a critical overview of the recent literature, the present article aimed to enrich the current knowledge about this topic by providing innovative suggestions, both practical and methodological, and specifically deepening the disability-related deficits and peculiarities of different age ranges. Moreover, since a multidisciplinary approach is advisable when designing and leading exercise protocols tailored to visually impaired individuals, such innovative hints also highlighted the central role of the adapted physical activity specialist, hence contributing to foster its official professional recognition and involvement in this field.

The 'Postural Rhythm' of the Ground Reaction Force during Upright Stance and Its Conversion to Body Sway-The Effect of Vision, Support Surface and Adaptation to Repeated Trials

The ground reaction force (GRF) recorded by a platform when a person stands upright lies at the interface between the neural networks controlling stance and the body sway deduced from centre of pressure (CoP) displacement. It can be decomposed into vertical (VGRF) and horizontal (HGRF) vectors. Few studies have addressed the modulation of the GRFs by the sensory conditions and their relationship with body sway. We reconsidered the features of the GRFs oscillations in healthy young subjects (n = 24) standing for 90 s, with the aim of characterising the possible effects of vision, support surface and adaptation to repeated trials, and the correspondence between HGRF and CoP time-series. We compared the frequency spectra of these variables with eyes open or closed on solid support surface (EOS, ECS) and on foam (EOF, ECF). All stance trials were repeated in a sequence of eight. Conditions were randomised across different days. The oscillations of the VGRF, HGRF and CoP differed between each other, as per the dominant frequency of their spectra (around 4 Hz, 0.8 Hz and <0.4 Hz, respectively) featuring a low-pass filter effect from VGRF to HGRF to CoP. GRF frequencies hardly changed as a function of the experimental conditions, including adaptation. CoP frequencies diminished to <0.2 Hz when vision was available on hard support surface. Amplitudes of both GRFs and CoP oscillations decreased in the order ECF > EOF > ECS ≈ EOS. Adaptation had no effect except in ECF condition. Specific rhythms of the GRFs do not transfer to the CoP frequency, whereas the magnitude of the forces acting on the ground ultimately determines body sway. The discrepancies in the time-series of the HGRF and CoP oscillations confirm that the body's oscillation mode cannot be dictated by the inverted pendulum model in any experimental conditions. The findings emphasise the robustness of the VGRF "postural rhythm" and its correspondence with the cortical theta rhythm, shed new insight on current principles of balance control and on understanding of upright stance in healthy and elderly people as well as on injury prevention and rehabilitation.

Effects of Music Listening on Postural Balance in Adolescents with Visual Impairment

We aimed to investigate the effect of music on visually impaired adolescents' postural balance across different somatosensory and vestibular input conditions. We recruited 19 adolescent participants (9 males, 10 females) with severe congenital visual impairment. We recorded their mean center of pressure velocity (CoP_Vm) during static upright bipedal standing under somatosensory (firm and foam surfaces) and vestibular (head facing forward (HFF), head rotated 90° to the right (HRR), and head rotated 90° to the left (HRL)) perturbations in three auditory conditions (no-music, listening to Jupiter, and listening to their preferred music). We found that CoP_Vm decreased significantly when listening to both Jupiter and preferred music, compared to the no-music condition on both firm (p < .05) and foam (p < .001) surfaces and with the HFF (p < .05), rotated to the right (p < .001) or rotated to the left (p < .001). Moreover, CoP_Vm values increased significantly with somatosensory manipulation (p < .001) in all the auditory conditions and with vestibular manipulation (p < .01) only in the no-music condition. We concluded that listening to both Jupiter and preferred music improved postural balance in visually impaired adolescents, even in challenged postural conditions.

Effects of the Interference of Sensory Systems on Postural Control in Congenitally Blind Subjects

The postural system requires the sensory systems to maintain postural control (PC). Blind subjects use the somatosensory system to keep PC whereas sighted subjects use the visual system. So what happens to PC when challenging the sensory systems? We analyzed the center of pressure (COP) in ten blind and 10 sighted subjects under conditions: eyes open/closed (interference of visual system) and on firm/foam surfaces (interference of somatosensory system). We found that under the condition of eyes open on a firm surface, the blind subjects relied on the somatosensory system, whereas sighted subjects relied on the visual system. However, when eyes closed and on foam surface, similar behavior was found in both groups for all COP variables. In general blind subjects use their somatosensory system as the main sensory input to maintain PC.

Body Balance Analysis in the Visually Impaired Individuals Aged 18-24 Years

BACKGROUND

Proper body balance is maintained by both sensory, i.e., vision, hearing, vestibular, and proprioception, and motor nervous systems. Visual control facilitates balance both in a static position, as well as during movement. Visual dysfunctions can adversely affect balance and stability control.

METHODS

The study comprised a group of 30 individuals visually impaired from birth aged 18-24 years. The control group consisted of 50 persons in the same age range as the study group. The trial was performed as four separate tests: two on a stable surface platform, and two on an unstable surface platform.

RESULTS

No statistically significant differences were found in the posturography test on the stable platform between the study groups. When tested on an unstable ground surface, the visually impaired subjects obtained showed worse performance than the sighted persons. Statistically significant differences were observed in the majority of the analyzed results.

CONCLUSIONS

Visually impaired individuals present a poorer ability to maintain balance under dynamic conditions. Tests conducted on the unstable surface platform seem to be more relevant and applicable in the diagnosis of the subjects with visual impairment, as they differentiate the subjects to a greater extent.

Posturographic Analysis in Patients Affected by Central and Peripheral Visual Impairment

Although vision loss is known to affect equilibrium maintenance, postural control in patients affected by low vision has been poorly investigated. We evaluated postural stability and the ability to use visual, proprioceptive and vestibular information in different low vision patterns. Ten adults with normal vision (NC), fourteen adults affected by central visual impairment (CLV) and eight adults affected by peripheral visual impairment (PLV) were enrolled in our study. Patients underwent visual, vestibular and postural evaluation (bedside examination, Computed Dynamic Posturograophy). Motor Control Tests were performed to analyze automatic postural adaptive responses elicited by unexpected postural disturbances. Clinical evaluations did not show abnormality in all patients. In the Sensory Organization Test, CLV and PLV patients performed more poorly in conditions 3-6 and 3-4, as compared to NC subjects. The condition 5 score was significantly lower in the CLV group with respect to the PLV patients. Composite equilibrium scores demonstrated significant differences between low-vision subjects vs. NC subjects. No differences were found for somatosensorial contribution. Visual afferences showed lower values in all visually impaired subjects, while vestibular contribution was lower in the CLV patients as compared to the NC and PLV patients. MCT latencies were significantly worse in the CLV subjects. In the low-vision patients, postural control was modified with a specific pattern of strategy adaptation. Different modulations of postural control and different adaptive responses seemed to characterize CLV patients as compared to PLV subjects.

Analysis of Visual Risk Factors of Anterior Cruciate Ligament Injury of Knee Joint

This study aimed to explore whether the defect of visual function is a risk factor of knee anterior cruciate ligament (ACL) sports injury and to provide a theoretical basis for the primary prevention of ACL sports injury. This cross-sectional study included 392 participants divided into two groups: the sports injury group (287 with sports injury of knee) and the control group (105 healthy volunteers). Participants in the sports injury group were further divided into the ACL-Intact group (133) and the ACL-Deficient group (154). Participants in the sports injury group received a questionnaire about the conditions of their injury (including injury action, site condition, weather, contact) and a visual examination by synoptophore (including binocular vision, subjective and objective oblique angle, visual fusion range, stereoacuity). Participants in the control group only received the visual examination. In the end, we found that low visual fusion range (p = 0.003) and injury action, especially quick turn (p = 0.001), sudden stop (p < 0.001) and jump (p = 0.001), are the major risk factors for ACL injury in the analysis of the integrated data. In addition, athletes with low vision fusion range have increased risk of ACL sports injury when they make a sudden stop on wooden floor, plastic floor or cement floor on cloudy days (OR = 13.208). Visual factors, especially low fusion range, significantly increase the risk of ACL sports injury.

Can stabilization analysis following a single leg drop jump be compared between young and middle-aged adults

We aimed to verify whether the computational approaches previously proposed to analyze stability after a single-leg drop-jump (SLDJ) could be applied to a population of middle-aged adults. Fifteen middle-aged (56.4 ± 4.6 years) and 15 young adults (26.7 ± 3.9 years) performed five SLDJs. Stabilization measurements included (1) time to stabilization (TTS) based on vertical ground reaction force (GRF) (TTSv) and a fixed stabilization threshold; (2) TTS based on medio-lateral GRF (TTSml) using five different methods to preprocess the signal and stabilization threshold; (3) early medio-lateral stabilization- the averaged absolute values of the GRF in 0.2-1.4 s post-landing; (4) late medio-lateral stabilization - the averaged absolute values of the GRF at 1 s-5 s after landing. TTSv showed longer TTS values in middle-aged participants. In addition, middle-aged adults showed greater sway in late stabilization. However, TTSml values varied considerably between calculation methods, and early stabilization showed no significant differences between groups except in the first 0.2 s after landing. The results of the current study suggest that TTS calculations are sensitive to signal and threshold selection, and to the processing method. Calculations based on a fixed threshold are more appropriate for studying dynamic postural stability in middle age. With appropriate method selection, a decreased stabilizing performance can be demonstrated in middle-aged adults compared to young adults.

The effects of acoustic and optokinetic stimulus on the postural stability

Objectives

This article addresses the question of whether the simultaneous auditory and optokinetic stimulation affects the postural stability differently than only the stimulation with a single auditory or optokinetic stimulus.

Methods

The study involved 30 volunteers. The postural stability was evaluated by means of the posturography platform, which allows for both stable and dynamic posturography tests as well as for applying optokinetic stimulus. Three series of measurements were performed in each patient: measurements on an only with the optokinetic stimulus, measurements using only the acoustic stimulus, and finally measurements with both stimuli applied simultaneously.

Results

The results indicate that there are statistically significant differences in the findings obtained with the simultaneous auditory and visual stimulation and the observed results with only one of the stimuli on the dynamic platform. Hence, on the basis of the results obtained, it is possible to conclude that the acoustic stimulus has the potential to help maintain a stable posture. However, this process is not sufficiently compensated with the optokinetic stimulation alone.

Conclusion

The sense of sight may be essential for the maintenance of a stable posture. The presence of a sound stimulus improves the postural stability, although this improvement does not compensate for the disturbance caused by the optokinetic stimulus. Hence, functioning of auditory and visual system can influence patients posture.

Level of Evidence

4.

Pattern Strabismus in a Tertiary Hospital in Southern China: A Retrospective Review

Background and objectives: To analyze demographic and clinical features of pattern strabismus patients and assess the relationship among these clinical variables and risk factors. Materials and Methods: Medical records of pattern strabismus patients who had undergone strabismus surgery at our center between 2014 and 2019 were retrospectively reviewed. Data collected included gender, age at onset, age at surgery, refraction, Cobb angle, pre- and post-operative deviations in the primary position, up- and downgaze, angle of ocular torsion, type/amount of pattern, grade of oblique muscle function and presence/grade of binocular function. To verify the clinical significance of the Cobb angle, 666 patients who had undergone surgery within one week after ocular trauma between 2015 and 2021 were enrolled as controls. Results: Of the 8738 patients with horizontal strabismus, 905 (507 males and 398 females) had pattern strabismus, accounting for 10.36%. Among these 905 patients, 313 showed an A-pattern and 592 showed a V-pattern. The predominant subtype was V-exotropia, followed by A-exotropia, V-esotropia and A-esotropia. Over half of these patients (54.6%) manifested an A- or V-pattern in childhood. The overall mean ± SD Cobb angle was 5.03 ± 4.06° and the prevalence of thoracic scoliosis was 12.4%, both of which were higher than that observed in normal controls (4.26 ± 3.36° and 7.8%). Within A-pattern patients, 80.2% had SOOA and 81.5% an intorsion, while in V-pattern patients, 81.5% had IOOA and 73.4% an extorsion. Patients with binocular function showed decreases in all of these percent values. Only 126 (13.9%) had binocular function, while 11.8% of A-pattern and 15.1% of V-pattern patients still maintained binocular function. Pre-operative horizontal deviation was negatively correlated with binocular function (r = −0.223, p < 0.0001), while the grade of oblique muscle overaction was positively correlated with the amount of pattern (r = 0.768, p < 0.0001) and ocular torsion (r = 0.794, p < 0.0001). There were no significant correlations between the Cobb angle and any of the other clinical variables. There were 724 patients (80.0%) who had received an oblique muscle procedure and 181 (20.0%) who received horizontal rectus muscle surgery. The most commonly used procedure consisted of horizontal rectus surgery plus inferior oblique myectomy (n = 293, 32.4%), followed by isolated horizontal rectus surgery (n = 122, 13.4%). Reductions of pattern were 14.67 ± 6.93 PD in response to horizontal rectus surgery and 18.26 ± 7.49 PD following oblique muscle surgery. Post-operative deviations were less in V- versus A-pattern strabismus. Post-operative binocular function was obtained in 276 of these patients (30.5%), which represented a 16.6% increase over that of pre-operative levels. The number of patients with binocular function in V-pattern strabismus was greater than that of A-pattern strabismus (p = 0.048). Conclusions: Of patients receiving horizontal strabismus surgery, 10.36% showed pattern strabismus. In these patients, 54.6% manifested an A- or V-pattern in childhood, and V-exotropia was the most frequent subtype. Pattern strabismus patients showed a high risk for developing scoliosis. Cyclovertical muscle surgery was performed in 724 of these patients (80.0%), and horizontal rectus surgery was effective in correcting relatively small levels of patterns. Binocular function represented an important factor as being involved with affecting the occurrence and development of pattern strabismus.

Mobile Health App for Adolescents: Motion Sensor Data and Deep Learning Technique to Examine the Relationship between Obesity and Walking Patterns

With the prevalence of obesity in adolescents, and its long-term influence on their overall health, there is a large body of research exploring better ways to reduce the rate of obesity. A traditional way of maintaining an adequate body mass index (BMI), calculated by measuring the weight and height of an individual, is no longer enough, and we are in need of a better health care tool. Therefore, the current research proposes an easier method that offers instant and real-time feedback to the users from the data collected from the motion sensors of a smartphone. The study utilized the mHealth application to identify participants presenting the walking movements of the high BMI group. Using the feedforward deep learning models and convolutional neural network models, the study was able to distinguish the walking movements between nonobese and obese groups, at a rate of 90.5%. The research highlights the potential use of smartphones and suggests the mHealth application as a way to monitor individual health.

Effects of Stroboscopic Vision on Postural Control in Individuals With and Without Chronic Ankle Instability

Objectives: Patients with chronic ankle instability (CAI) tend to increase their reliance on visual information, perhaps to compensate for proprioceptive deficits which appear after lateral ankle sprains. However, little is known about how limited visual feedback would alter static postural control in patients with CAI compared with copers and controls. The purpose of this study was to identify the effects of reduced visual feedback via stroboscopic glasses on static balance among CAI, coper, and uninjured control participants. Design: Controlled trial in a laboratory setting. Methods: Nineteen patients with CAI, 19 copers, and 19 controls participated in this study. Each participant performed a single-leg balance test with eyes open, stroboscopic vision, and eyes closed. Two-way analysis of variance (group × condition) was used to examine the differences between condition (eyes open, stroboscopic vision, and eyes closed) and group (CAI, coper, and control). Results: There were no significant interactions for static balance. Although there were no group effects among 3 groups for all static postural control measures, visual condition main effects were present (P < .01) for each dependent variable. Across all groups, anterior–posterior and mediolateral center of pressure path length and center of pressure velocity with stroboscopic vision were greater than the condition with eyes open (P < .01) and less than with eyes closed (P < .01). Conclusions: Stroboscopic glasses could be cost effective visual disruption equipment during static postural control regardless of ankle injury history. However, incorporating static balance with limited visual information via stroboscopic glasses could not display the differences in visual reliance in individuals with and without CAI.

Changes in postural balance associated with a woman's aging process

CONTEXT

Aging causes a progressive worsening in postural balance, affecting functional independence and increasing the risk of falls.

OBJECTIVE

The aim of the study was to evaluate the effect of aging on the static balance in women from 50-years to 89-years of age.

DESIGN

This was a cross-sectional study, with 400 irregularly active women were evaluated and grouped by age: Group 6^th decade (age 50 to 59) ‒ 58 participants; Group 7^th decade (age 60 to 69) ‒ 214 participants; Group 8^th decade (age 70 to 79) ‒ 92 participants; Group 9^th decade (age 80 to 89) ‒ 36 participants. Postural balance was evaluated using a portable force platform in a standard standing position, with Eyes Open (EO) and Eyes Closed (EC).

RESULTS

In the two measurement conditions, the elderly women in Group 9^th decade presented mediolateral displacement and range, and mean velocity greater than the women's values in Groups 6^th and 7^th decade. In the EO e EC situation, the displacement was higher in the elderly Group 9^th decade compared to younger groups. Group 8^th has a mean velocity greater than Group 6^th decade in the EO situation.

CONCLUSIONS

Posturography showed a decline in postural balance with advancing age, suggesting that the 9^th decade of life is a borderline age to this detriment due to an increase in postural instability.

Path to Diagnosis and Clinical Characteristics of Advanced Glaucoma at Initial Diagnosis: a Tertiary Single Center Experience

Purpose: As routine health examinations become more common, many patients first diagnosed with glaucoma have advanced glaucoma. We analyzed the routes to diagnosis and the characteristics of patients initially diagnosed with advanced glaucoma.Methods: We retrospectively retrieved the medical records of patients first diagnosed with advanced glaucoma in our tertiary care center. The inclusion criteria were a mean deviation (MD) less than -12 dB on the visual field test, accompanied by structural damage. All patients were classified in terms of unilateral/bilateral disease, the intraocular pressure before medication, and lens status. We divided patients into those with monocular or binocular advanced glaucoma, high- or normal-pressure glaucoma, and those who were pseudophakic or phakic.Results: We included 73 patients of mean age 69.3 years. The visual field test MD was -19.6 dB. In those with binocular advanced glaucoma, incidental ophthalmic examination was the most common means of diagnosis (52.2%). Central-island visual field defects were the most common defects (54.2%). In those with monocular advanced glaucoma, glaucoma-associated symptoms most commonly triggered diagnosis (46.9%). Both superior and inferiorvisual field defects were the most common defects (42.8%). Glaucoma-associated symptoms were present in 68.2 and 22.8% of patients with high- and normal-pressure glaucoma, respectively. Central-island visual field defects were present in 43.6 and 29.4% of those with high- and normal-pressure glaucoma, respectively.Conclusions: We analyzed the routes to diagnosis and the clinical characteristics of patients with advanced glaucoma. In those with binocular disease, glaucoma was most commonly diagnosed on incidental ophthalmic examination. Central-island visual field defects were the most common defects in patients with binocular and high-pressure glaucoma, and the pseudophakic group. A multi-center longitudinal study on risk factors for delayed glaucoma diagnosis is needed.

Vision Evaluation Tools for Adults With Acquired Brain Injury: A Scoping Review

Background. Unrecognized visual deficits (VDs) following an acquired brain injury (ABI) may impact clients’ rehabilitation. Little is known about evaluation tools used in vision rehabilitation. Purpose. To systematically explore the literature describing evaluation tools used for VD on adults with ABI. Method. Using a scoping review methodology, we searched in MEDLINE(Ovid), Embase, CINAHL, PsycINFO, and the grey literature from inception to 2020. Quantitative and thematic analyses were performed. Findings. Of the 83 studies reporting on 86 evaluation tools, 47% used multiple tools to assess VD. Tools were mostly used by occupational therapists and psychologists to evaluate intermediate, intermediate to high, and high-level visual skills. Clinicians tend to select specific tools that focus on different levels of the hierarchy of visual skills. Implications. Future research should investigate the optimal timeframe for assessment of VD and the psychometric properties of tools to ensure comprehensive VD evaluation.

Acute effects of acupuncture in balance and gait of Parkinson disease patients - A preliminary study

INTRODUCTION

Balance and gait disorders are relevant symptoms in the quality of life of Parkinson's patients. Currently, there is no therapy to reverse or treat this condition. Acupuncture treatment is believed to improve motor ability through the cortico-basal-thalamus-cortical-ganglia.

AIM

To investigate qualitatively the acute effect of acupuncture on balance and gait in Parkinson's disease in 7 patients.

METHODS

This is a randomized and controlled crossover study. The same individual patient was part of both, experimental (real acupuncture) and control group (false acupuncture/sham), and the sequence was randomized. Balance and gait parameters were measured at two different moments, before and after treatment, using four force platforms as well as the collection of 3D markers positions taken by 11 cameras. Images were analyzed using Qualisys Track Manager software that let us extract data related to the quality of gait and balance.

RESULTS

Statistically significant differences were found in gait speed (p = 0.016), gait cadence (p = 0.006), support base width (p = 0.0001), medio-lateral oscillation (p = 0.017), left-right step length (p = 0.0002), and stride length: right-right (p = 0.0000) and left-left (p = 0.0018), time of left support phase (p = 0.029), right support phase (p = 0.025) and double support phase (p = 0.015), between the initial and final moments for the experimental group. Differences in right-left stride length were found for both groups.

CONCLUSION

Our results suggest that the acupuncture protocol used objectively could improve gait in Parkinson disease patients. A deep research involving a statistical evaluation supported on a larger number of voluntaries should be accomplished to confirming these promising preliminary results.

Association Between Visual Field Damage and Gait Dysfunction in Patients With Glaucoma

Importance

Gait dysfunction is common in older people with visual impairment and is a major cause of falls.

Objective

To compare 3-year longitudinal changes in gait measures across the spectrum of baseline visual field (VF) damage in glaucoma.

Design, Setting, and Participants

A post hoc analysis was designed on September 1, 2018, following a prospective cohort study, which enrolled older adults with glaucoma or suspected glaucoma from September 2013 to March 2015 and followed up for up to 3 years. Baseline VF damage was defined by integrated VF (IVF) sensitivity and categorized as normal/mild (IVF >28 dB), moderate (IVF, 23-28 dB), and severe (IVF, <23 dB). Each participant walked on an electronic walkway back and forth twice at normal pace each study year. Linear mixed-effects models evaluated longitudinal change in gait outcomes (1) stratified within each VF severity category and (2) across the range of IVF sensitivity. Analysis took place from October 2019 to October 2020.

Main Outcomes and Measures

Three-year changes in 7 gait assessments under usual-pace walking, including base support and its coefficient of variation, stride length and its coefficient of variation, stride velocity and its coefficient of variation, and cadence.

Results

Of 241 participants, the mean (SD) age was 70.8 (7.7) years, 116 (48.2%) were women, and 70 (29.0%) were African American. When comparing longitudinal gait changes over 3 years across the spectrum of IVF sensitivity, each 5-unit (dB) decrement was associated with more rapid declines in stride velocity (-0.05 z score unit/y; 95% CI, -0.09 to -0.01; P = .01) and cadence (-0.07 z score unit/y; 95% CI, -0.10 to -0.03; P < .001). When evaluating gait changes within each glaucoma severity group, shorter stride length was associated with persons with normal/mild (-0.06 z score unit/y; 95% CI, -0.10 to -0.03; P = .001), moderate (-0.08 z score unit/y; 95% CI, -0.12 to -0.04; P < .001), and severe VF damage (-0.16 z score unit/y; 95% CI, -0.24 to -0.07; P < .001), while stride velocity (-0.18 z score unit; 95% CI, -0.28 to -0.07; P = .002) and slower cadence (-0.15 z score unit; 95% CI, -0.25 to -0.04; P = .006) were associated with those with severe VF damage.

Conclusions and Relevance

At worse levels of baseline VF damage, patients with glaucoma in this study demonstrated an exacerbated decline in walking speeds (ie, stride velocity and cadence), indicating that mobility speeds decrease faster over time in older adults with glaucoma.

Anthropometric and demographic properties affect balance in healthy adults: an observational study

BACKGROUND

Anthropometric and demographic properties may affect balance, but there is no consensus on this subject; so, there is a need for studies that explore it. This study aimed to assess the relationship between balance and anthropometric as well as demographic properties; and to determine the effect of anthropometric and demographic properties on balance in healthy adults.

METHODS

Sixty healthy adults were included in this study. The ages of the participants were questioned; height, body weight, Body Mass Index, head circumference, upper extremity, lower extremity, and foot length were evaluated, and shoe numbers were recorded. Balance assessments were performed with the Balance Master System device.

RESULTS

The mean age of the participants was 23.50±1.97 years. The balance developed with age (P<0.05), while there was a negative correlation between height and balance (P<0.05). Weight gain affected balance negatively (P<0.05). The increase in head circumference, extremity, and foot length was associated with a deterioration in balance (P<0.05).

CONCLUSIONS

The results of the current study were showed that anthropometric and demographic properties affect balance. The increase in some of the anthropometric and demographic properties including height, weight, head circumference, extremity, and foot length harms the balance. During balance assessments, anthropometric and demographic characteristics should be considered as a factor that affects balance.

Smartphone-Based Inertial Odometry for Blind Walkers

Pedestrian tracking systems implemented in regular smartphones may provide a convenient mechanism for wayfinding and backtracking for people who are blind. However, virtually all existing studies only considered sighted participants, whose gait pattern may be different from that of blind walkers using a long cane or a dog guide. In this contribution, we present a comparative assessment of several algorithms using inertial sensors for pedestrian tracking, as applied to data from WeAllWalk, the only published inertial sensor dataset collected indoors from blind walkers. We consider two situations of interest. In the first situation, a map of the building is not available, in which case we assume that users walk in a network of corridors intersecting at 45° or 90°. We propose a new two-stage turn detector that, combined with an LSTM-based step counter, can robustly reconstruct the path traversed. We compare this with RoNIN, a state-of-the-art algorithm based on deep learning. In the second situation, a map is available, which provides a strong prior on the possible trajectories. For these situations, we experiment with particle filtering, with an additional clustering stage based on mean shift. Our results highlight the importance of training and testing inertial odometry systems for assisted navigation with data from blind walkers.

Association of posturography with clinical measures in balance rehabilitation of ataxic patients

The assessment of balance includes posturography measures and clinical balance tests in individuals with ataxia. Although both advantages and disadvantages of these assessments have been stated, no relationship between them in individuals with ataxia has been shown in the literature. The aim of this cross-sectional study was to investigate the relationships between commonly used clinical balance tests and posturography measures in ataxic individuals. The study included a total of 42 patients (mean age: 33.90 ± 8.75 years) with different diagnoses causing ataxia. The sensory organization test (SOT), limits of stability (LOS), unilateral stance and rhythmic weight shift (RWS) tests in computerized dynamic posturography and the clinical balance tests of Berg Balance Scale (BBS), International Cooperative Ataxia Rating Scale (ICARS) and timed up and go (TUG) test were used to assess balance. The Spearman correlation test was used to evaluate the relationships between the clinical balance tests and posturography variables. Moderate and strong correlations were found between the ICARS, BBS and TUG scores and Unilateral Stance sway velocity, directional control parameter of RWS and LOS (P < 0.01-0.05). The ICARS and BBS scores were correlated with the SOT-Composite Equilibrium Score (P < 0.01-0.05). The results of this study suggest the use of both posturography and clinical balance tests in the rehabilitation of ataxic individuals with mild-moderate balance impairment, because posturography variables determine the underlying cause of imbalance and clinical tests evaluate balance in functional activities.

Measurement of Human Walking Movements by Using a Mobile Health App: Motion Sensor Data Analysis

Background

This study presents a new approach to measure and analyze the walking balance of humans by collecting motion sensor data in a smartphone.

Objective

We aimed to develop a mobile health (mHealth) app that can measure the walking movements of human individuals and analyze the differences in the walking movements of different individuals based on their health conditions. A smartphone’s motion sensors were used to measure the walking movements and analyze the rotation matrix data by calculating the variation of each xyz rotation, which shows the variables in walking-related movement data over time.

Methods

Data were collected from 3 participants, that is, 2 healthy individuals (1 female and 1 male) and 1 male with back pain. The participant with back pain injured his back during strenuous exercise but he did not have any issues in walking. The participants wore the smartphone in the middle of their waistline (as the center of gravity) while walking. They were instructed to walk straight at their own pace in an indoor hallway of a building. The walked a distance of approximately 400 feet. They walked for 2-3 minutes in a straight line and then returned to the starting location. A rotation vector in the smartphone, calculated by the rotation matrix, was used to measure the pitch, roll, and yaw angles of the human body while walking. Each xyz-rotation vector datum was recalculated to find the variation in each participant’s walking movement.

Results

The male participant with back pain showed a diminished level of walking balance with a wider range of xyz-axis variations in the rotations compared to those of the healthy participants. The standard deviation in the xyz-axis of the male participant with back pain was larger than that of the healthy male participant. Moreover, the participant with back pain had the widest combined range of right-to-left and forward-to-backward motions. The healthy male participant showed smaller standard deviation while walking than the male participant with back pain and the female healthy participant, indicating that the healthy male participant had a well-balanced walking movement. The walking movement of the female healthy participant showed symmetry in the left-to-right (x-axis) and up-to-down (y-axis) motions in the x-y variations of rotation vectors, indicating that she had lesser bias in gait than the others.

Conclusions

This study shows that our mHealth app based on smartphone sensors and rotation vectors can measure the variations in the walking movements of different individuals. Further studies are needed to measure and compare walking movements by age, gender, as well as types of health problems or disease. This app can help in finding differences in gait in people with diseases that affect gait.

DYNAMIC POSTURAL BALANCE IS MEDIATED BY ANTHROPOMETRY AND BODY COMPOSITION IN OLDER WOMEN

OBJECTIVE

To investigate the relationship between anthropometry and body composition with dynamic postural balance in elderly women with low bone mineral density (BMD).

METHODS

45 older women (≥ 60 years), low BMD and nutritional diagnosis of low weight to overweight. For the assessment of body composition, Dual energy X-ray emission densitometry and anthropometric examination were used to measure: body mass (kg), height (cm) and BMI (k/m2). The assessment of dynamic postural balance was performed by the mini Balance Master Evaluation System clinical test and the computerized Balance Master® System test by the Sit to Stand and Step Up/Over tests.

RESULTS

There was a negative correlation between miniBESTest (r = - 0.566; p ≤ 0.001) and time to ascend and descend step (r = - 0.393; p ≤ 0.007) with fat mass, and positive correlation with miniBESTest (r = 0.526; p ≤0.001) and time to go up and down a step with muscle mass (r = 0.297; p ≤ 0.04). As for anthropometric variables, only height showed a positive correlation (r = 0.296; p ≤ 0.04) with the speed in the sit and stand test.

CONCLUSION

Lean mass reduces postural oscillations; in contrast, fat mass negatively interfered with dynamic postural balance in women with low BMD. Height was related to dynamic postural balance, the taller the elderly, the worse their balance. Level of Evidence II, Prognostic Studies - Investigating the Effect of a Patient Characteristic on the Outcome of Disease.

Impaired eye tracking is associated with symptom severity but not dynamic postural control in adolescents following concussion

PURPOSE

The purpose of the study was to (1) examine the relationship between self-reported symptoms and concussion-related eye tracking impairments, and (2) compare gait performance between (a) adolescents with a concussion who have normal eye tracking, (b) adolescents with a concussion who have abnormal eye tracking, and (c) healthy controls.

METHODS

A total of 30 concussed participants (age: 14.4 ± 2.2 years, mean ± SD, 50% female) and 30 controls (age: 14.2 ± 2.2 years, 47% female) completed eye tracking and gait assessments. The BOX score is a metric of pupillary disconjugacy, with scores <10 classified as normal and ≥10 abnormal. Symptoms were collected using the Post-Concussion Symptom Scale (PCSS), and gait speed was measured with triaxial inertial measurement units. We conducted a linear regression to examine the relationship between PCSS and BOX scores and a two-way mixed effects analysis of variance to examine the effect of group (abnormal BOX, normal BOX, and healthy control) on single- and dual-task gait speed.

RESULTS

There was a significant association between total PCSS score and BOX score in the concussion group (β = 0.16, p = 0.004, 95% confidence interval (95%CI): 0.06‒0.27), but not in the control group (β = 0.21, p = 0.08, 95%CI: -0.03 to 0.45). There were no significant associations between PCSS symptom profiles and BOX scores in the concussion or control groups. There were also no significant differences in single-task (Abnormal: 1.00 ± 0.14 m/s; Normal: 1.11 ± 0.21 m/s; Healthy: 1.14 ± 0.18 m/s; p = 0.08) or dual-task (Abnormal: 0.77 ± 0.15 m/s; Normal: 0.84 ± 0.21 m/s; Healthy: 0.90 ± 0.18 m/s; p = 0.16) gait speed.

CONCLUSION

The concussed group with impaired eye tracking reported higher total symptom severity, as well as worse symptom severity across the 5 PCSS symptom domain profiles. However, eye tracking deficits did not appear to be driven by any particular symptom domain. While not statistically significant, the slower gait speeds in those with abnormal BOX scores may still be clinically relevant since gait-related impairments may persist beyond clinical recovery.

Role of vision in static balance in persons with and without visual impairments

BACKGROUND

Vision is one of the elements of the system responsible for maintaining static balance. Any visual impairments or conditions hampering the reception of visual stimuli may affect static balance. It would be interesting to identify to what extent people with different degrees of dysfunction and in different conditions are able to compensate for the inability to receive visual stimuli while maintaining balance.

AIM

The aim of this study was to determine the role of the vision in maintaining static balance. This study sought to assess balance and the degree of compensation when the possibility of receiving visual stimuli is limited in persons without visual impairments and persons with varying degrees of visual impairments.

DESIGN

Controlled observational study.

SETTING

Main University Laboratory.

POPULATION

The study included 122 individuals, 81 of whom were visually impaired. The participants with visual impairments were divided into three groups according to their levels of disability.

METHODS

Subjects performed tests on a stabilographic platform: standing on both feet with eyes open and closed, single right- and left-leg stance with eyes open and closed. The center of pressure path length and the visual inspection indicator were analysed. Significance of differences between the groups regarding the visual inspection indicator and tests performed with eyes open and closed was assessed with the use of the Mann-Whitney U test. The effects and interactions between variables were verified using the ANOVA test for the main effects and factorial designs.

RESULTS

Differences were noted in balance of persons without visual impairments in single-leg stance tests with eyes open and closed as well as when standing on both feet with eyes open and closed. In persons with visual impairment, significant differences were observed in the single left-leg stance test with eyes open and closed only. Testing conditions and disability levels exerted a significant influence on static balance in single-leg tests.

CONCLUSIONS

The findings of the study confirm the role of vision in maintaining balance in the context of factors that may affect it, i.e. conditions (eyes open or closed) and possibilities of receiving visual stimuli (disability level).

CLINICAL REHABILITATION IMPACT

The significance of the visual effect was noted in single-leg tests. More demanding tests detect compensatory mechanisms of balance more accurately.

ANTHROPOMETRIC FACTORS AND BODY COMPOSITION AND THEIR RELATIONSHIP WITH DYNAMIC BALANCE TESTS

ABSTRACT Introduction: The limit of stability is characterized by the maximum angle of inclination that an individual can reach and greater variability in extreme conditions; it is a bold and/or dangerous motor control strategy. Objective: Assess whether anthropometric measurements and body composition interfere with limits of stability and weight-bearing at different speeds in adults. Methods: Eighty-seven subjects of both sexes aged between 20 and 40 years were analyzed using anthropometric assessment and body composition. A force platform, limits of stability (LoS) and rhythmic weight shift (RWS) tests were used for the balance assessments. Results: In the LoS test, being female was negatively correlated with foot size and reaction time, and positively correlated with maximum excursion. In the RWS test, the female group had a negative correlation with height and upper limb length (ULL), with mediolateral directional control. The male group had a negative correlation with ULL and laterolateral directional control. Conclusion: Body composition variables do not interfere in the LoS and RWS tests in subjects with normal body mass index (BMI) values, except for bone densitometry (BMD) in women. As regards anthropometric parameters, height, ULL and foot size in the female and male groups were as follows: ULL and foot size exert little influence on postural balance control. Level of evidence II, Diagnostic studies - Investigation of a diagnostic test.

Poorer Visual Acuity is Independently Associated With Impaired Balance and Step Length But Not Overall Physical Performance in Older Adults

This study examined the association between varying levels of visual acuity (VA) and physical performance (Short Physical Performance Battery) in older adults. A cross-sectional analysis of participants aged ≥50 years with a clinical diagnosis of vision loss across two studies was undertaken. Of 434 (96%) participants with available VA data, 74% (320/434) had nil, 7% (32/434) had mild, 8% (33/434) had moderate, and 11% (49/434) had severe visual impairment. Poorer VA of both better and worse eye was found to be significantly associated with poorer standing balance (p = .006 and p = .004, respectively); worse VA of the better eye was significantly associated with increased number of steps per meter (p = .005). Mean total Short Physical Performance Battery score of this study population was lower than published normative data for this age group. Physical activity programs for older people with reduced VA should be targeted at improving balance and gait skills to reduce falls risk.

The Consequences of Glaucoma on Mobility and Balance Control in the Older Adults: A Cross-Sectional Study

The aim of the study was to explore the functional impairments and related factors in older adults with moderate to advanced stages of glaucoma. Nineteen patients with glaucoma and 19 participants with no ocular disease performed step test and balance control tasks with analysis of overall stability index and fall risk index. Monocular and binocular Humphrey Visual Field tests were used to estimate visual field defect severity. The International Physical Activity Questionnaire was used to measure physical activity level. Patients with glaucoma showed poorer values for most of the mobility and balance control parameters with medium and large effect sizes (0.3-0.5). Mobility scores in patients were partly associated with their monocular visual field defect (rs = .507, p < .05). Low physical activity was identified as a risk factor for falls (rs = -.453, p < .05) and postural instability (rs = -.457, p < .05). Functional declines in dynamic tasks were not related to glaucoma severity. Older adults with glaucoma display impairment with mobility and balance control compared to controls, associated with the degree of monocular visual field loss and lower daily physical activity.

Gait and Balance as Predictors and/or Mediators of Falls in Glaucoma

Purpose

To investigate the association between balance and gait measures with fall rates in glaucoma patients.

Methods

Balance and gait were measured for 239 participants with glaucoma or suspected glaucoma. Daily falls were evaluated over 24 months. Annual accelerometer trials captured average daily steps. Multivariable negative binomial models evaluated balance and gait associations with average daily steps and rates of falls per time or step, as well as whether balance and gait parameters mediated the association between integrated visual field (IVF) sensitivity and falls.

Results

Average age was 70.5 years (SD = 7.6), and 22% of the participants had moderate to severe visual field damage. Over the first 12 months of the follow-up, the cumulative probability of falling one or more times was 44.8%, and the cumulative probability of falling two or more times was 17.7%. Gait deficits were associated with fewer daily steps (P < 0.03), but no balance parameters were (P > 0.19). Worse balance was associated with a higher rate of falls per year and step (P < 0.03). No gait measures were associated with the rate of falls per year (P > 0.17). More time in double support and greater swing time variability were associated with higher falls per step, and higher velocity and faster cadence were associated with fewer falls per step (P < 0.05 for all). Neither gait nor balance measures mediated the relationship between visual field damage and fall rates. IVF remained an independent predictor of falls per step (rate ratio = 1.36 to 1.48; P < 0.001 to P < 0.005) in multivariable models including individual balance/gait parameters.

Conclusions

Although balance and gait measures are associated with fall rates, they do not explain why persons with greater visual field damage fall more frequently, suggesting the importance of other potential factors such as hazard perception.

Physical Frailty and Fall Risk in Community-Dwelling Older Adults: A Cross-Sectional Study

Introduction

Frailty is a condition in older adults with decreased physical and cognitive performance that can affect health outcomes associated with fracture, disability, and falls. The aim of this study was to compare fall risk with different physical frailty statuses and investigate factors associated with fall risk in community-dwelling older adults.

Methods

The population studied included 367 older adults (mean age = 73.2 years ± 7.0; 237 females (64.6%) and 130 males (35.4%)) who live in Chiang Mai, Thailand. This study was of cross-sectional design. Fried's phenotype was used to screen the physical frailty status. The physiological profile assessment (PPA) was used to screen for fall risk. One-way ANOVA analysis was used to compare the fall risk between the different levels of frailty status. Linear regression analysis was used to assess the association between frailty status and fall risk.

Results

The prevalence of the frailty group was 8.7% and that of the prefrailty group was 76.8%. The three statuses of frailty identified were found to have different levels of risk of falling. The frailty group had a higher fall risk than the nonfrailty group and the prefrailty group. In addition, the nonfrailty group had a lower fall risk than the prefrailty group.

Conclusion

The frailty group had the highest fall risk in this cohort of older adults living in a community-dwelling facility. Therefore, it is important to assess the frailty status among older adults as it can be a predictor for fall risk. This assessment will therefore lead to a reduction in the rate of disability and death in the community.

Effect of sensory stimulation applied under the great toe on postural ability in patients with fibromyalgia

Fibromyalgia (FM) is a chronic pain syndrome, characterised by several symptoms. One of the most prevalent symptoms in FM is balance impairment that compromise the autonomy, function and performance status of patients.Purpose: The main objective of the present study was to evaluate the effect of sensory stimulation provided by the use of a low additional thickness of 0.8 mm placed under the great toes bilaterally on the centre of pressure (CoP) measures in patients with FM. It was hypothesised that postural ability would change with a low focal additional thickness used to compute these measures.Materials and Method: Twenty-four patients with FM voluntarily participated in this study. Postural performance during quiet standing was investigated through the CoP displacements recorded using a force-plate. Sensory stimulation was provided by a small additional thickness of 0.8 mm placed under the great toe bilaterally and two conditions were compared: additional thickness 0 (control) and 0.8 mm.Results: An improvement of body balance through spatial parameters with sensory cutaneous stimulation applied under the great toe bilaterally were observed in patients with FM. Our results showed a significant decrease of surface area and mean speed of CoP, associated to a significant decrease of variance of speed. An additional observation is that sagittal (Y) mean position of the CoP gets more anterior (+ 5 mm) relative to control condition.Conclusion: These findings brings new clinical perspectives in the development of intervention strategies in the management of patients with FM and balance disorders, completing validated therapeutic strategies.

Advanced glaucoma at diagnosis: current perspectives

Presentation with advanced glaucoma is a significant risk factor for lifetime blindness. The asymptomatic nature of glaucoma, particularly in early disease, means that substantial vision loss in one eye does not always translate into a perceptible loss of visual function. This, along with the lack of an effective screening strategy, contributes to late presentation. Those most at risk of presenting with advanced glaucoma have asymptomatic high intraocular pressure (IOP), no family history of glaucoma, are socially disadvantaged, and do not attend sight testing. Patients with glaucoma may have impaired functionality for daily activities, such as reading, walking and driving. Quality of life measures have shown this to be significantly worse in patients with more severe visual field loss, particularly if bilateral. In addition, quality of life decreases faster with further bilateral visual field loss when advanced visual field damage is present. Management of these patients requires disproportionally more resources than those with earlier disease. Both medical and surgical options are used as the initial approach to treat patients presenting with advanced glaucoma. The most recently published National Institute for Health and Care Excellence (NICE) guidelines suggest that patients presenting with advanced disease should be offered trabeculectomy as a primary intervention. However, more evidence is required to determine the best initial management. The Treatment of Advanced Glaucoma Study (TAGS) is being conducted, comparing primary medical management with primary mitomycin C-augmented trabeculectomy for people presenting with advanced open-angle glaucoma. The results of TAGS will provide robust evidence for the most appropriate initial intervention.

Measuring Disability in Glaucoma

BACKGROUND

Glaucomatous visual field loss can have far-reaching and debilitating consequences on an individual, affecting one's ability to perform many important tasks. Although assessment of glaucoma-related disability constitutes an important part of clinical care, there remains a lack of organized, detailed information on the most suitable methods to capture disability in glaucoma.

PURPOSE

This review details the available methods to measure glaucoma-related disability and highlights important findings from studies utilizing these various methods.

METHODS

The literature was reviewed to identify papers evaluating disability in glaucoma and findings were summarized by research methodology used and area of impairment.

RESULTS

Identified methods for capturing glaucoma-related disability included qualitative descriptions, glaucoma-specific quality of life questionnaires, vision-specific questionnaires, general health questionnaires, functional domain-specific questionnaires, evaluation of task performance, event assessment (ie, falls and motor vehicle accidents), and real-world behavior (ie, daily physical activity). Findings using these methods show a strong relationship between glaucoma and/or glaucoma severity and difficulties with reading, driving, mobility, and other tasks such as prehension and facial recognition. In addition, glaucoma has financial and psychological implications on the patient, and can affect caregivers in some cases as well.

CONCLUSIONS

A wide variety of research tools have been used to characterize the disability resulting from glaucoma. Together, these tools show that glaucoma affects many abilities which are important for independent living. Strengths and limitations of the various research techniques are discussed so that future studies may use the method(s) most suitable for answering the research question posed.

Controle postural estático e risco de quedas em mulheres idosas com e sem incontinência urinária

RESUMO A incontinência urinária (IU) está associada à ocorrência de quedas em idosos e pode ter relação com déficits no controle postural. O objetivo deste trabalho é comparar o controle postural estático, na condição de olhos abertos e fechados, e o risco de quedas entre idosas com IU e idosas sem IU. A amostra foi dividida em dois grupos: idosas com IU (n=21, idade=65,33±4,57 anos) e idosas sem IU (n=19, idade=66,37±5,26 anos). As características da perda urinária do grupo com IU foram avaliadas por meio do International Consultation on Incontinence Questionnaire: Short Form (ICIQ-SF). O controle postural estático dos grupos foi mensurado pelo deslocamento do centro de pressão (COP) por meio de uma plataforma de força; e o risco de quedas foi avaliado pelo teste timed up and go. Para a análise estatística, foi utilizado o teste U de Mann-Whitney e o teste qui-quadrado. A maioria das participantes com IU perdiam urina em pequena quantidade e todas perdiam em baixa frequência. Não foi observada diferença entre os grupos em relação às variáveis do COP (p>0,05) e o risco de quedas (p=0,082). Entretanto, na análise intragrupos, houve diferença na velocidade do COP de ambos os grupos na comparação olhos abertos versus olhos fechados (p<0,05). Não houve diferença no controle postural estático e no risco de quedas entre idosas com e sem IU.

Does the Level of Difficulty in Balancing Tasks Affect Haptic Sensitivity Via Light Touch?

The purpose of this study was to determine whether the contribution of bimanual light touch varies according to the difficulty level of postural tasks (e.g., vision occlusion, height of support surface). Fourteen healthy young adults each were asked to stand in a tandem position, on a 20-cm height balance beam. Postural tasks included light touch and no touch conditions in two vision conditions, nonvision and full vision. The root mean square of amplitude of oscillation (mediolateral), mean velocity, ellipse area, and path length of the center of pressure revealed that touch conditions reduced sway to a greater extent in the elevated support surface, nonvision condition. Highly unstable balance tasks increase the optimization of light touch and affect the attenuation of postural sway.

Effects of sport on static balance in athletes with visual impairments

BACKGROUND

Proper balance is crucial for postural control and physical activity performance. Issues related to balance as well as effects of various factors on balance are in the center of attention of specialists in a number of fields including sport. Research results show that every sports discipline demands different motor preparation (including balance) and persons with visual impairments exhibit worse balance compared to their sighted counterparts. Therefore, this study sought to assess static balance in athletes with visual impairments with reference to the type of sport they did, the length of their training experience, training loads and dysfunction level.

METHODS

The study involved 57 men (shooters, tandem cyclists, football and goalball players) with visual impairments. AMTI stabilographic platform was used to assess static balance. The study participants performed the following tests: standing on both feet with eyes open and closed and single-leg stance with eyes open and closed.

RESULTS

Balance in tests performed while standing on both feet did not differentiate athletes in terms of the sport they did. Static balance of athletes with visual impairments significantly differs in the single leg stance. Better balance was observed in tests with eyes open. Taking into consideration sports disciplines practiced by the athletes, significant differences in balance in single left leg tests with eyes open and closed were observed. Athletes training more than five hours per week manifested better balance compared to those who practiced less than five hours per week.

CONCLUSIONS

The findings indicate that athletes performing particular sports may use strategies of maintaining balance that result from the structure of these sports. The lack of differences in balance among athletes with different degrees of dysfunction may indicate their high fitness levels and show how balance is affected by physical activity performance. Results of the analysis of balance with regard to the length of training experience may suggest that it is not this factor but rather the quality of training that may exert an influence on this ability.

The effect of time restricted visual sensory input on asymmetry of ground reaction force components in female children

The association between visual sensory and the asymmetry index of sit-to-stand ground reaction force characteristics is not fully understood. Therefore, the purpose of this study was to investigate asymmetry index of sit-to-stand ground reaction forces, their times-to-peak, vertical loading rate, impulses, and free moment in blind and sighted children. 15 female children with congenital blindness and 30 healthy girls with no visual impairments volunteered to participate in this study. The girls with congenital blindness were placed in one group and the girls with no visual impairments were randomly divided into two groups of 15. The two condition groups consisted of, one eyes open and the other, eyes closed. The participants in the eyes closed group were asked to close their eyes for 20 min before the test, whereas those in the eyes open group kept their eyes open. Kinematic and kinetic data were collected using an eight-camera motion analysis system synchronized with two force plates embedded in the floor. A MANOVA test was run for between-group comparisons. There were no distinctive biomechanical alternations in all axes of ground reaction forces and their times-to-peak, vertical loading rate, impulses and free moments in congenital blindness and eyes closed groups compared with the eyes open group. However, eyes closed was associated with increased total time and second phase duration of sit-to-stand performance by 69% (p = 0.008) and 62% (p = 0.008), respectively. These findings reveal that individuals who are visually restricted in the short term, do not develop stereotypical movement strategies for sit-to-stand.

Neural Control of Balance During Walking

Neural control of standing balance has been extensively studied. However, most falls occur during walking rather than standing, and findings from standing balance research do not necessarily carry over to walking. This is primarily due to the constraints of the gait cycle: Body configuration changes dramatically over the gait cycle, necessitating different responses as this configuration changes. Notably, certain responses can only be initiated at specific points in the gait cycle, leading to onset times ranging from 350 to 600 ms, much longer than what is observed during standing (50-200 ms). Here, we investigated the neural control of upright balance during walking. Specifically, how the brain transforms sensory information related to upright balance into corrective motor responses. We used visual disturbances of 20 healthy young subjects walking in a virtual reality cave to induce the perception of a fall to the side and analyzed the muscular responses, changes in ground reaction forces and body kinematics. Our results showed changes in swing leg foot placement and stance leg ankle roll that accelerate the body in the direction opposite of the visually induced fall stimulus, consistent with previous results. Surprisingly, ankle musculature activity changed rapidly in response to the stimulus, suggesting the presence of a direct reflexive pathway from the visual system to the spinal cord, similar to the vestibulospinal pathway. We also observed systematic modulation of the ankle push-off, indicating the discovery of a previously unobserved balance mechanism. Such modulation has implications not only for balance but plays a role in modulation of step width and length as well as cadence. These results indicated a temporally-coordinated series of balance responses over the gait cycle that insures flexible control of upright balance during walking.

Visual, musculoskeletal and balance symptoms in individuals with visual impairment

BACKGROUND

Visual impairment is globally among the most prevalent disabilities. Research concerning the health consequences of visual deficits is challenged by confounding effects of age, because visual impairment becomes more prevalent with age. This study investigates the influence of visual deficits on visual, musculoskeletal and balance symptoms in adults with and without visual impairment, while controlling for age effects.

METHODS

Thirty-nine patients with visual impairment, aged 18-72 years, were compared to 37 age-matched controls with normal vision, allocated to two age groups: < 45 and ≥ 45 years. Self-reported symptoms were measured using the Visual, Musculoskeletal and Balance Symptoms Questionnaire and compared with demographic and optometric variables.

RESULTS

In total, patients with visual impairment reported more symptoms than age-matched normally sighted controls. Younger adults in the control group were almost free from symptoms, whereas younger adults with visual impairment reported levels of symptoms equal to older adults with visual impairment. Multiple logistic regression modelling identified use of eyeglasses, magnifying aids and presence of anisometropia to be the most influential risk factors for reporting visual, musculoskeletal and balance symptoms, with accentuated influence on balance symptoms.

CONCLUSIONS

People with visual impairments and people with age-related normal visual deficits are both predisposed to report visual, musculoskeletal and balance symptoms relative to people without visual defects or need for eye-wear correction. Age-related variations in symptoms were observed in the control groups but not in the visual impairment groups, with younger visual impairment patients reporting as many symptoms as older visual impairment patients. These findings indicate a need for a wider interdisciplinary perspective on eye care concerning people with visual impairment and people with need for habitual daily use of eye wear correction.

Effects of vision and cognitive load on static postural control in subjects with and without patellofemoral pain syndrome

OBJECTIVE

To compare the effects of vision and cognitive load on static postural control in subjects with and without patellofemoral pain syndrome (PFPS).

METHODS

Twenty-eight PFPS patients and 28 controls participated in the study. Postural control was assessed in isolation as well as with visual manipulation and cognitive loading on symptomatic limb. The outcome measures of postural control were quantified in terms of area, anterior-posterior (AP), medial-lateral (ML), and mean velocity (MV) of the displacements of center of pressure (COP). In addition, cognitive performance (auditory Stroop task) was measured in the forms of average reaction time and error ratio in baseline (sitting) and different postural conditions.

RESULTS

PFPS subjects showed greater increases in area (p = 0.01), AP (p = 0.01), and ML (p = 0.05) displacements of COP in the blindfolded tasks as compared to control group. However, cognitive load did not differently affect postural control in the two groups. Although PFPS and control group had similar reaction times in the sitting position (p = 0.29), PFPS subjects had longer reaction times than healthy subjects in dual task conditions (p = 0.04).

CONCLUSION

Visual inputs seem to be essential for discriminating postural control between PFPS and healthy individuals. PFPS patients biased toward decreasing cognitive performance more than healthy subjects when they perform the single leg stance and cognitive task concurrently.

Does structural leg-length discrepancy affect postural control? Preliminary study

BACKGROUND

Leg-length inequality results in an altered position of the spine and pelvis. Previous studies on the influence of leg asymmetry on postural control have been inconclusive. The purpose of this paper was to investigate the effect of structural leg-length discrepancy (LLD) on the control of posture.

METHODS

We studied 38 individuals (19 patients with structural LLD, 19 healthy subjects). The examination included measurement of the length of the lower limbs and weight distribution as well as a static posturography. All statistical analyses were performed with Statistica software version 10.0. Non-parametrical Kruskal-Wallis with Dunn's post test and Spearman test were used. Differences between the groups and correlation between mean COP sway velocity and the value of LLD as well as the value of LLD and weight distribution were assumed as statistically significant at p < 0.05.

RESULTS

There was a significant difference in the asymmetry of weight distribution between the group of patients and the healthy subjects (p = 0.0005). Differences in a posturographic examination between the groups were not statistically significant (p > 0.05). Meaningful differences in mean COP velocity in mediolateral direction between tandem stance with eyes open and closed were detected in both groups (in controls p = 0.000134, in patients both with the shorter leg in a front and rear position, p = 0.029, p = 0.026 respectively). There was a positive moderate correlation between the value of LLD and the value of mean COP velocity in normal standing in mediolateral direction with eyes open (r = 0.47) and closed (r = 0.54) and in anterioposterior plane with eyes closed (r = 0.05).

CONCLUSIONS

The fact that there were no significant differences in posturography between the groups might indicate compensations to the altered posture and neuromuscular adaptations in patients with structural leg-length inequality. LLD causes an increased asymmetry of weight distribution. This study confirmed a fundamental role of the sight in postural control, especially in unstable conditions. The analysis of mean COP sway velocity may suggest a proportional deterioration of postural control with the increase of the value of leg-length asymmetry.

TRIAL REGISTRATION NUMBER

Trial registry: ClinicalTrials.gov NCT03048656 , 8 February 2017 (retrospectively registered).

Gait Implications of Visual Field Damage from Glaucoma

PURPOSE

To evaluate fall-relevant gait features in older glaucoma patients.

METHODS

The GAITRite Electronic Walkway was used to define fall-related gait parameters in 239 patients with suspected or manifest glaucoma under normal usual-pace walking conditions and while carrying a cup or tray. Multiple linear regression models assessed the association between gait parameters and integrated visual field (IVF) sensitivity after controlling for age, race, sex, medications, and comorbid illness.

RESULTS

Under normal walking conditions, worse IVF sensitivity was associated with a wider base of support (β = 0.60 cm/5 dB IVF sensitivity decrement, 95% confidence interval [CI] = 0.12-1.09, P = 0.016). Worse IVF sensitivity was not associated with slower gait speed, shorter step or stride length, or greater left-right drift under normal walking conditions (P > 0.05 for all), but was during cup and/or tray carrying conditions (P < 0.05 for all). Worse IVF sensitivity was positively associated with greater stride-to-stride variability in step length, stride length, and stride velocity (P < 0.005 for all). Inferior and superior IVF sensitivity demonstrated associations with each of the above gait parameters as well, though these associations were consistently similar to, or weaker than, the associations noted for overall IVF sensitivity.

CONCLUSION

Glaucoma severity was associated with several gait parameters predictive of higher fall risk in prior studies, particularly measures of stride-to-stride variability. Gait may be useful in identifying glaucoma patients at higher risk of falls, and in designing and testing interventions to prevent falls in this high-risk group.

TRANSLATIONAL RELEVANCE

These findings could serve to inform the development of the interventions for falls prevention in glaucoma patients.

Role of vision in sighted and blind soccer players in adapting to an unstable balance task

This study tested whether a compensatory hypothesis exists on postural control during standing unstable balance tasks comparing blind soccer players (n = 7) to sighted soccer players (n = 15) and sighted sedentary individuals (n = 6). All subjects performed a pre-test, a training of ten practice trials on a single day, and a post-test balance test. All tests were performed on an unstable surface placed on a force platform and under closed-eyes conditions, and a final test was performed with open eyes. Balance performance was assessed by resultant distance (RD) and the magnitude of mean velocity (MV) of the centre of pressure (CoP) displacement, and EMG signals from the gastrocnemius lateralis, tibialis anterior, rectus femoris, and peroneus longus were measured with surface electromyography. Principal component analysis (PCA) on EMG muscular activation was used to assess EMG pattern differences during the balance tasks. All groups improved their performance, obtaining low scores for the closed-eyes condition balance task after the training period in RD, VM, and aids received to keep balance in the novel task, and no differences were found between groups or in interaction effects. Sighted individuals and the control group showed significantly lower RD and VM scores under open-eyes conditions than blind participants. As regards neuromuscular behaviour, three principal patterns explained 84.15% of the variability in the measured data. The theoretical improvement of the other senses caused by visual deprivation does not allow blind individuals to obtain better balance than sighted individuals under closed-eyes conditions, thereby reinforcing the prominent role of vision in integrating and processing the other sensory inputs. In addition, blind individuals seem to increase their muscular co-activation as a safety strategy, but this behaviour is not different to that shown by sighted people under closed-eyes conditions.

Postural balance control in women with generalized joint laxity

Objectives

This study aims to investigate the potential relationship between joint laxity and postural balance by using tetra-ataxiometric posturography (Tetrax®).

Patients and methods

A total of 69 healthy volunteers were included in the study and classified into three groups based on their hypermobility severity determined with Beighton-Horan hypermobility index scores. Of those, 29 participants were non-hypermobile, 13 participants were mildly hypermobile and remaining 27 patients had severe hypermobility. Postural control of the participants was evaluated by using the Tetrax® device in eight different positions. The stability index, Fourier index, weight distribution index, and synchronization index scores of each participant were recorded.

Results

We found that the participants with severe hypermobility exhibited significantly higher stability index scores while the position of the head is extended and rotated right. The weight distribution index on elastic surfaces was impaired in non-hypermobile and severely hypermobile participants. We observed that the Fourier Index scores were higher at a higher-medium frequency (0.5-1 Hz) in participants with severe hypermobility. There was no difference between the groups in terms of synchronization index scores.

Conclusion

These findings suggest that severely hypermobile individuals have a decreased postural stability in head-extended and head- rotated positions when compared to individuals who are non-hypermobile. This increased instability may lead to an increased risk of musculoskeletal injuries, especially in sports that require extension and rotation movements of the head.