Body weight is a strong predictor of postural stability

The relationship between low energy availability, injuries, and bone health in recreational female athletes

Background

Low energy availability (LEA) causes pathophysiology of the female athlete's body affecting the bone and reproductive health and was observed to have a high prevalence in recreational female athletes previously. The aim of this study was to analyse the relationship between low energy availability in females questionnaire (LEAF-Q), bone mineral density (BMD), and postural stability in recreational athletes.

Methods

Recreational female athletes (n = 24, age: 23.71 ± 2.94, Tier I) completed LEAF-Q, postural stability measurement during quiet stance (Zebris platform FDM; GmbH) and their BMD was measured using DXA (Hologic QDR Horizon A). Non-parametric statistical tests were used to analyse the relationships between LEAF-Q, BMD, and postural stability and to compare differences between participants divided by the LEAF-Q score and its subscales.

Results

Risk of LEA was observed in 50% of recreational athletes participating in this study. Up to 46% of participants perceived menstrual bleeding changes related to training and 37.50% experienced menstrual dysfunction. Body composition and body weight fluctuations were observed to affect postural stability and BMD. With the risk score for LEA, the BMD and postural stability were not negatively affected in recreational athletes. However, the high number of recreational athletes in the risk score for LEA and menstrual dysfunctions highlights the need for public health programs aimed to increase awareness of LEA and its health consequences and for open communication about the menstrual cycle. Future longitudinal studies observing LEA, BMD, menstrual function, postural stability, and their interrelationship in female athletes are needed to increase the knowledge of this topic.

International validation of meaningfulness of postural sway and gait to assess myeloneuropathy in adults with adrenoleukodystrophy

BACKGROUND

The most common manifestation of X-linked adrenoleukodystrophy (ALD) is a slowly progressive myeloneuropathy, which leads to imbalance and gait disturbances. The variable progression of the disease complicates evaluation of its progression rate. Wearable sensors allow for easy and frequent balance and gait collection. This study reports baseline data from a longitudinal study on the quantitative assessment of balance and gait with wearable sensors and their clinical relevance.

METHODS

Data were collected from adult patients in two institutions. Postural body sway and gait parameters were measured using accelerometers. Disease severity was measured by the Expanded Disability Severity Scale (EDSS). Falling frequency and quality of life (QOL) were collected in men. The relationship between sway and gait variables and EDSS score, participants' use of a walking aid, and falling frequency was evaluated.

RESULTS

One hundred twenty individuals with ALD were included. Sway variables significantly differentiate participants' assistive device use. Sway and gait variables were correlated to the EDSS in both sexes. Both gait speed and sway were correlated with falling frequency in men from one institution. Select QOL subscores were correlated with the EDSS in males from one institution. Accelerometry generated comparable results across sites.

DISCUSSION

This study confirms the clinical correlation between spinal cord disease and imbalance and gait in ALD. For the first time, this study shows clinically meaningful relationships for sway and gait with use of an assistive device, falling frequency and QOL. Wearable accelerometers are a valid means to measure sway and gait in ALD. These measures are promising outcomes for clinical trial designs to assess myeloneuropathy in ALD and to monitor disease progression in individuals.

A validation study to analyze the reliability of center of pressure data in static posturography in dogs

Introduction

Center of pressure (COP) parameters are frequently assessed to analyze movement disorders in humans and animals. Methodological discrepancies are a major concern when evaluating conflicting study results. This study aimed to assess the inter-observer reliability and test-retest reliability of body COP parameters including mediolateral and craniocaudal sway, total length, average speed and support surface in healthy dogs during quiet standing on a pressure plate. Additionally, it sought to determine the minimum number of trials and the shortest duration necessary for accurate COP assessment.

Materials and methods

Twelve clinically healthy dogs underwent three repeated trials, which were analyzed by three independent observers to evaluate inter-observer reliability. Test-retest reliability was assessed across the three trials per dog, each lasting 20 seconds (s). Selected 20 s measurements were analyzed in six different ways: 1 × 20 s, 1 × 15 s, 2 × 10 s, 4 × 5 s, 10 × 2 s, and 20 × 1 s.

Results

Results demonstrated excellent inter-observer reliability (ICC ≥ 0.93) for all COP parameters. However, only 5 s, 10 s, and 15 s measurements achieved the reliability threshold (ICC ≥ 0.60) for all evaluated parameters.

Discussion

The shortest repeatable durations were obtained from either two 5 s measurements or a single 10 s measurement. Most importantly, statistically significant differences were observed between the different measurement durations, which underlines the need to standardize measurement times in COP analysis. The results of this study aid scientists in implementing standardized methods, thereby easing comparisons across studies and enhancing the reliability and validity of research findings in veterinary medicine.

Framework for early detection and classification of balance pathologies using posturography and anthropometric variables

BACKGROUND

Early detection of balance-related pathologies in adults using Posturography, anthropometric and personal data is limited. Our goal is to address this issue. It will enable us to identify adults in early stages of balance disorders using easily accessible and measurable data.

METHODS

Open-source data of 163 subjects (47 males and 116 females) is used to train and test classification algorithms. Features include mean and standard deviation of the center of pressure displacement, obtained through posturography, the anthropometric and personal variables (age, sex, body mass index, foot length), and Trail Making Test scores. 75% of the data is employed for training and 25% of the data is used for testing. It is then validated using an indigenously collected dataset of healthy individuals.

FINDINGS

Accuracy and Sensitivity, both, increases when anthropometric and personal variables are included alongside center of pressure features for classification. Specificity decreases slightly with the addition of anthropometric and personal variables with center of pressure displacement feature, which also affects the classification algorithms' performance. Standard deviation of the center of pressure displacement is found to be more effective than the mean value. A similar trend of the increased performance is observed during validation, except when neural networks were used for the classification.

INTERPRETATION

Posturography data, Anthropometric measurements, personal data and self-assessment scales can identify balance issues in adults, making it suitable for community health centers with limited resources. Early detection prompts timely medical care, improving the management of disorders and thus enhancing the quality of life through rehabilitation.

Muscle mass and chronic dizziness: a cross-sectional study of a Korean population

BACKGROUND AND OBJECTIVES

Weight gain is associated with imbalance in older people. In contrast, overweightness or mild obesity is less common in patients with chronic dizziness. This paradox may be, at least in part, related to differences in the body composition indices adopted in the previous studies. This study aimed to determine any association between the predicted body composition and chronic dizziness or imbalance of unknown causes.

METHODS

We measured the lean body mass, body fat mass, and appendicular skeletal mass in 9243 people who participated in the Korean National Health and Nutrition Examination Survey 2019-2021. Sarcopenia was defined according to the Asian Working Group for Sarcopenia's guidelines. Obesity was defined as a body fat percentage of ≥ 25% for men and ≥ 35% for women.

RESULTS

The participants with chronic dizziness had a lower body mass index than those without (p = 0.001). Furthermore, sarcopenia was more common in those with chronic dizziness. In contrast, the degree of obesity was comparable in both groups. Multiple logistic regression analysis showed that sarcopenia was associated with a higher risk of chronic dizziness (odds ratio = 1.6, 95% confidence interval: 1.1-2.5; p = 0.026).

DISCUSSION

Given the association of sarcopenia with chronic dizziness or imbalance, muscle mass may play a role in maintaining balance and stability. Physical exercise could be recommended to increase muscle mass in patients with chronic dizziness/imbalance and sarcopenia. Additional research is required to establish a causal relationship between chronic dizziness and sarcopenia.

Effect of Vision and Surface Slope on Postural Sway in Healthy Adults: A Prospective Cohort Study

Postural stability requires an interaction between cognitive, perceptual, sensory, and motor functions. Thus, impairment in any of these systems may affect postural balance. This study assessed the effect of visual input and surface slope on postural stability. The study was conducted on healthy participants, 11 females and 11 males who were 24-34 years of age. They were asked to perform still upright bipedal standing on flat and +/-20° sloped surfaces with eyes open (EO) and closed (EC). Six center of pressure (COP) parameters were measured by posturography. A significant relationship was observed between COP parameters, standing conditions, and body mass index. Gender had no significant effect on the COP. The loss of visual input within each standing condition did not affect the COP parameters. In contrast, differences were observed between standing on a flat surface and uphill with EC and between standing on a flat surface and downhill with EC and EO. When the participants were standing on inclined surfaces, the loss of vision significantly increased the postural instability. Young healthy adults demonstrated the greatest difficulty in standing uphill with EC. This was followed by standing downhill with EC and standing downhill with EO.

The effect of surgical repair of the chest on postural stability among patients with pectus excavatum

Pectus excavatum is the most encountered of chest wall deformities. It may produce respiratory and cardiovascular symptoms, hence surgical repair of this defect is performed. The procedure involving the insertion of metal bars under the sternum (the Nuss procedure) usually brings significant improvement to patients. However, the effect of the repair on the postural stability of patients has not been studied so far. To investigate the problem of patients' stability in the postoperative period male patients with pectus excavatum (n = 21) and healthy controls (n = 22) were included in the study. Using posturography methods, we showed a negative impact of the pectus excavatum repair surgery on patients' postural stability in the first postoperative phase. The centre of pressure displacement parameters used to measure postural stability were lower after the repair for both, the frontal and sagittal plane as well as for the velocity of displacements in the sagittal plane in the double stance with eyes open. Poorer postural stability was also found in patients with pectus excavatum when compared to healthy controls. Our findings may be useful for functional monitoring in the evaluation and surgical management of pectus excavatum patients and also when designing the rehabilitation of patients undergoing the Nuss procedure.

Adipose tissue deposition region affects fall risk in people with obesity: A systematic review and meta-analysis

This review sought to meta-analyze previous research observing the effects of fat mass distribution on the fall risk among people with obesity. The literature search yielded five qualified studies enrolling 1218 participants (650 with android vs. 568 with gynoid). The outcome variables included the annual fall prevalence (primary outcome) and the center of pressure (COP) movement measurements during a posturography test (secondary) among people with android or gynoid obesity. Meta-analyses were conducted using the inverse variance weighted random-effects model. The odds ratio (OR) and standardized mean difference (SMD) were used as the effect size for the primary and secondary variables, respectively. The results revealed that more people with android obesity fall annually than their gynoid obesity counterparts (OR = 1.78 [1.34, 2.37], p < 0.0001). People with android obesity also exhibited significantly faster overall COP velocity (SMD = 0.49 [0.11, 0.88], p = 0.01) during standing compared to individuals with gynoid obesity. Our results indicated that people with android obesity could have a greater fall risk than those with gynoid obesity. Given the limited number of studies included, more well-designed and quality work is desired to further clarify how fat mass distribution alters the fall risk among people with obesity. A standardized approach to quantify the fat mass distribution (android vs. gynoid) is imperatively needed for people with obesity.

Acute effects of static balance exercise combined with different levels of blood flow restriction on motor performance fatigue as well as physiological and perceptual responses in young healthy males and females

PURPOSE

This study investigated the acute effects of a static balance exercise combined with different blood flow restriction (BFR) pressures on motor performance fatigue development and recovery as well as physiological and perceptual responses during exercise in males and females.

METHODS

Twenty-four recreational active males (n = 13) and females (n = 11) performed static balance exercise on a BOSU ball (3 sets of 60 s with 30 s rest in-between) on three separate (> 3 days) laboratory visits with three different BFR pressures (80% arterial occlusion pressure [AOP], 40%AOP, 30 mmHg [SHAM]) in random order. During exercise, activity of various leg muscles, vastus lateralis muscle oxygenation, and ratings of effort and pain perception were recorded. Maximal squat jump height was measured before, immediately after, 1, 2, 4, and 8 min after exercise to quantify motor performance fatigue development and recovery.

RESULTS

Quadriceps muscle activity as well as ratings of effort and pain were highest, while muscle oxygenation was lowest in the 80%AOP compared to the 40%AOP and SHAM condition, with no differences in postural sway between conditions. Squat jump height declined after exercise with the highest reduction in the 80%AOP (- 16.4 ± 5.2%) followed by the 40%AOP (- 9.1 ± 3.2%), and SHAM condition (- 5.4 ± 3.3%). Motor performance fatigue was not different after 1 min and 2 min of recovery in 40% AOP and 80% AOP compared to SHAM, respectively.

CONCLUSION

Static balance exercise combined with a high BFR pressure induced the largest changes in physiological and perceptual responses, without affecting balance performance. Although motor performance fatigue was increased by BFR, it may not lead to long-term impairments in maximal performance.

The Complexity of Head Movement is Correlated with Learning about Affordances for Walking

We asked whether the quantitative kinematics of standing postural activity might be related to short-term learning of affordances. Standing participants viewed a narrow path for 15 s, and then gave perceptual reports about the distance that they could walk along the path while wearing a weighted vest (novel affordance) or while not wearing the vest (familiar affordance). In a control condition, participants gave perceptual reports about egocentric distance along the path. During the 15 s viewing intervals, we measured the kinematics of head and torso movement as standing participants made a series of 12 perceptual reports. Perceptual reports improved across trials, but only in the condition in which participants were asked to perceive a novel affordance. The dynamical complexity of head movement changed across trials as participants gave perceptual reports about the novel affordance, but did not change systematically when perceiving a familiar affordance, or a non-affordance egocentric distance. We argue that the dynamical complexity of postural activity may have served an exploratory function supporting the learning of a novel affordance. Our results are consistent with the broader hypothesis that affordances are learned through active engagement with the environment, rather than (for example) through abstract cognitive processing.

Balancing ability of patients with lumbar spinal canal stenosis

PURPOSE

To determine the relationship between postural sway and the severity of lumbar spinal canal stenosis as well as the effect on postoperative improvement.

METHODS

Stabilometry was performed before and 6 months after surgery in 52 patients (29 men and 23 women; mean age, 74.1 ± 7.8 years) who underwent decompression surgery for lumbar spinal canal stenosis. The environmental area (EA; the area surrounding the circumference of the stabilogram) and locus length per EA (L/EA) were evaluated. The patients were divided into moderate (n = 22) and severe (n = 30) groups according to the severity of canal stenosis. Patient characteristics and parameters were compared between the groups before and after surgery, including the visual analog scale (VAS) score for leg pain, Oswestry Disability Index (ODI), EA, and L/EA. In addition, factors affecting EA and L/EA were evaluated using multiple regression analysis.

RESULTS

Age (p = 0.031), preoperative EA (p < 0.001), preoperative L/EA (p = 0.032), and sagittal vertical axis (p = 0.033) were significantly different between groups. The VAS score and ODI significantly improved postoperatively in both groups (p < 0.001). The EA significantly improved postoperatively only in the severe group (p < 0.001), whereas the L/EA did not significantly improve in either group. Multiple regression analysis showed that only the severity of canal stenosis was significantly associated with preoperative EA (p = 0.030), whereas age (p = 0.040) and severity of canal stenosis (p = 0.030) were significantly associated with preoperative L/EA. Diabetes was significantly associated with postoperative EA (p = 0.046) and L/EA (p = 0.030).

CONCLUSION

The severity of canal stenosis affected abnormal postural sway, which improved after decompression surgery.

The impact of obesity on static and proactive balance and gait patterns in sarcopenic older adults: an analytical cross-sectional investigation

Background

Obesity is increasingly recognized as a significant factor in the susceptibility of older adults to falls and related injuries. While existing literature has established a connection between obesity and reduced postural stability during stationary stances, the direct implications of obesity on walking dynamics, particularly among the older adults with sarcopenia, are not yet comprehensively understood.

Objective

Firstly, to investigate the influence of obesity on steady-state and proactive balance, as well as gait characteristics, among older adults with sarcopenic obesity (SO); and secondly, to unearth correlations between anthropometric characteristics and balance and gait parameters in the same demographic.

Methods

A cohort of 42 participants was categorized into control (CG; n = 22; age = 81.1 ± 4.0 years; BMI = 24.9 ± 0.6 kg/m²) and sarcopenic obese (SOG; n = 20; age = 77.7 ± 2.9 years; BMI = 34.5 ± 3.2 kg/m²) groups based on body mass index (BMI, kg/m²). Participants were assessed for anthropometric data, body mass, fat and lean body mass percentages (%), and BMI. Steady-state balance was gauged using the Romberg Test (ROM). Proactive balance evaluations employed the Functional Reach (FRT) and Timed Up and Go (TUG) tests. The 10-m walking test elucidated spatiotemporal gait metrics, including cadence, speed, stride length, stride time, and specific bilateral spatiotemporal components (stance, swing, 1st and 2nd double support, and single support phases) expressed as percentages of the gait cycle.

Results

The time taken to complete the TUG and ROM tests was significantly shorter in the CG compared to the SOG (p < 0.05). In contrast, the FRT revealed a shorter distance achieved in the SOG compared to the CG (p < 0.05). The CG exhibited a higher gait speed compared to the SOG (p < 0.05), with shorter stride and step lengths observed in the SOG compared to the CG (p < 0.05). Regarding gait cycle phases, the support phase was longer, and the swing phase was shorter in the SOG compared to the CG group (p < 0.05). LBM (%) showed the strongest positive correlation with the ROM (r = 0.77, p < 0.001), gait speed (r = 0.85, p < 0.001), TUG (r = -0.80, p < 0.001) and FRT (r = 0.74, p < 0.001).

Conclusion

Obesity induces added complexities for older adults with sarcopenia, particularly during the regulation of steady-state and proactive balance and gait. The percentage of lean body mass has emerged as a crucial determinant, highlighting a significant impact of reduced muscle mass on the observed alterations in static postural control and gait among older adults with SO.

NZ-RugbyHealth Study: Current Postural Control Ability of Former Rugby Union and Non-contact Sport Players

BACKGROUND

Players in contact sports frequently experience mild traumatic brain (concussion) injuries (TBI). While there are known disruptions to balance following acute head trauma, it is uncertain if sport-related concussion injuries have a lasting impact on postural control.

AIM

To assess postural control in retired rugby players in comparison to retired non-contact sport players, and to evaluate any association with self-reported sport-related concussion history.

METHODS

Using a cross-sectional design, 75 players in the NZ-RugbyHealth study from three sports groups (44 ± 8 years; 24 elite rugby, 30 community rugby, 21 non-contact sport) took part in this study. The SMART EquiTest® Balance Master was used to assess participant's ability to make effective use of visual, vestibular and proprioceptive information using standardised tests. Postural sway was also quantified using centre of pressure (COP) path length. The relationship among sports group, sport-related concussion history and postural control was evaluated using mixed regression models while controlling for age and body mass index.

RESULTS

Limited significant differences in balance metrics were found between the sports groups. A statistically significant (p < 0.001) interaction indicated a relationship between COP path length and sport-related concussion history in the most challenging balance condition, such that path length increased as the number of previous sport-related concussions increased.

CONCLUSION

There was some evidence for a relationship between sport-related concussion recurrence in sports players and postural stability in challenging balance conditions. There was no evidence of impaired balance ability in retired rugby players compared with non-contact sport athletes.

Predictors of static and dynamic balance control in kidney transplant recipients

BACKGROUND

We aimed to evaluate balance control and lower extremity muscle strength in kidney transplant recipients (KTRs) including a comparison to a healthy control group and determine the predictors of static and dynamic balance control after kidney transplantation.

METHODS

In this study 40 KTRs and 40 healthy controls were included. Balance control was assessed using the Biodex balance system. The static postural stability test (SPST) and clinical test of sensory integration and balance (CTSIB) were used to assess static balance control whereas the dynamic postural stability test (DPST) and limits of stability test (LOST) were used for dynamic balance control. Lower extremity muscle strength was measured with a hand-held dynamometer. Renal functions and laboratory findings of KTRs were recorded.

RESULTS

All the stability index scores of SPST and sway index in CTSIB were significantly higher in KTRs compared to healthy controls. The right anteroposterior stability index score in DPST and the reaction time in LOST were significantly higher whereas overall score in LOST and lower extremity muscle strength were significantly lower in KTRs. The linear regression analysis revealed that hemoglobin was the predictor of static balance control accounting for 11% of the variance and body weight was the predictor of dynamic balance control accounting for 34% of the variance.

CONCLUSION

Balance control, both static and dynamic, are impaired in KTRs as well as lower extremity muscle strength. Hemoglobin level is a predictor of static balance control whereas body weight is a predictor of dynamic balance control after kidney transplantation.

Body mass index, systemic inflammation and cognitive performance in adolescents: A cross-sectional study

BACKGROUND

Excessive body weight has been related to lower cognitive performance. One of the mechanisms through which excess body weight may affect cognition is inflammation.

HYPOTHESIS

Our hypothesis is that both body mass index (BMI) and circulating levels of inflammatory biomarkers will be negatively related to cognitive performance.

DESIGN

Cross-sectional study.

SETTING

Users of the public health centres of the Consorci Sanitari de Terrassa (Terrassa, Spain) between 2010 and 2017 aged 12-21 years.

PARTICIPANTS

One hundred and five adolescents (46 normoweight, 18 overweight, 41 obese).

MEASUREMENTS

Levels of high sensitivity C-reactive protein, interleukin 6, tumour necrosis factor α (TNFα) and fibrinogen were determined from blood samples. Cognitive performance was evaluated and six cognitive composites were obtained: working memory, cognitive flexibility, inhibitory control, decision-making, verbal memory, and fine motor speed. A single multivariate general lineal model was used to assess the influence of the four inflammatory biomarkers, as well as participants' BMI, sex, and age on the 6 cognitive indexes.

RESULTS

An inverse relationship between BMI and inhibitory control (F = 5.688, p = .019; β = -0.212, p = .031), verbal memory (F = 5.404, p = .022; β = -0.255, p = .009) and fine motor speed (F = 9.038, p = .003; β = -0.319, p = .001) was observed. Levels of TNFα and fibrinogen were inversely related to inhibitory control (F = 5.055, p = .027; β = -0.226, p = .021) and verbal memory (F = 4.732, p = .032; β = -0.274, p = .005), respectively.

LIMITATIONS

The cross-sectional nature of the study, the use of cognitive tests designed for clinical purposes, and the use of BMI as a proxy for adiposity are limitations of our study that must be taken into account when interpreting results.

CONCLUSIONS

Our data indicate that some components of executive functions, together with verbal memory, are sensitive to specific obesity-related inflammatory agents at early ages.

Rehabilitation in Older Adults Affected by Immobility Syndrome, Aided by Virtual Reality Technology: A Narrative Review

Individual mobility deficit in older adults induces a variety of medical conditions, diminishing their functional capacity in pursuing activities of daily living. In immobility syndrome patients, such conditions are prone further deterioration through a drastically reduced scope of physical activity, owing mostly to poor self-motivation and the monotonous character of conventional rehabilitation regimens. As evidenced by published research, virtual reality technology solutions in rehabilitation management actually add significantly to patients' self-motivation, while promoting their active involvement in therapy through visual, auditory, and kinaesthetic stimuli. Effective rehabilitation training aided by virtual reality solutions helps patients acquire specific physical and cognitive skills to be subsequently emulated in the real-world environment. The extra added advantage lies in facilitating such training within patients' own home environments, combined with online monitoring of their progress, when not personally supervised by a physiotherapist, which also boosts the overall cost effectiveness of the therapeutic management itself. This narrative review appears to be the very first one principally focused on critically comparing individual immobilisation with immobility syndrome, especially through the application of the Authors' own substantial hands-on therapeutic experience in managing various rehabilitation schemes, specifically aided by diverse virtual reality technology solutions.

Effects of Physical Activity Program on Body Composition, Physical Performance, and Neuromuscular Strategies during Walking in Older Adults with Sarcopenic Obesity: Randomized Controlled Trial

The potential impact of a specific physical activity program on biomechanical gait parameters and neuromuscular strategies around the ankle joint in older adults with sarcopenic obesity (SO) remains largely unexplored. The objective of this study was to investigate the effectiveness of a 24-week posture, strengthening, and motricity (PSM) program on improving neuromuscular strategies and biomechanical gait parameters in older adults with SO. 40 participants were randomly assigned to either the trained group (TG) and the control group (CG). Only the TG received the PSM program. Standardized evaluations were performed before and after the intervention, including walking tests on an instrumented gait analysis treadmill to evaluate biomechanical gait parameters and EMG activity of ankle muscles. After the PSM program, TG exhibited an increase in comfortable walking speed (+80%, p < 0.001) and step length (+38%, p < 0.05). Moreover, TG demonstrated a reduction in CoP velocity (-26%, p < 0.01). These gait modifications were associated with decreased muscle activity during the different gait phases (p < 0.05). The PSM program effectively improved gait and neuromuscular capacities in older adults with SO. Notably, these results shed light on the remarkable trainability of neuromuscular capacities in older adults with SO, despite the adverse effects of aging and obesity.

Postural stability and plantar pressure parameters in healthy subjects: variability, correlation analysis and differences under open and closed eye conditions

Introduction: The "postural control system" acts through biomechanical strategies and functional neuromuscular adaptations to maintain body balance under static and dynamic conditions. Postural stability and body weight distribution can be affected by external sensory inputs, such as different visual stimuli. Little information is available about the influence of visual receptors on stabilometric and plantar pressure parameters. The aim of this study was to analyze variability, correlations, and changes in these parameters under open- (OE) and closed-eye (CE) conditions. Methods: A total of 31 stabilometric and plantar pressure parameters were acquired in 20 young and healthy adults during baropodometric examination performed in bipedal standing under both visual conditions. Variability of parameters was evaluated via the coefficient of variation, correlation analysis via Pearson's R2, and statistical differences via the Wilcoxon test. Results: High intra-subject repeatability was found for all plantar pressure parameters and CoP-speed (CV < 40%) under OE and CE conditions, while CoP-sway area (CoPsa) and length surface function (LSF) showed larger variability (CV > 50%). Mean and peak pressures at midfoot and total foot loads showed the least number of significant correlations with other parameters under both visual conditions, whereas the arch-index and rearfoot loads showed the largest number of significant correlations. The limb side significantly affected most plantar pressure parameters. A trend of larger LSF and lower CoPsa and mean and peak pressures at the right forefoot was found under the CE condition. Discussion: The present study provides a deeper insight into the associations between postural stability and foot load. Interesting postural adaptations, particularly with respect to different visual stimuli, the effect of the dominant side, and the specific role of the midfoot in balance control were highlighted.

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.

The Influence of Anthropometric Variables and Filtering Frequency on Center of Pressure Data

Good postural control is considered to be a key component of an active lifestyle, and numerous studies have investigated the Center of Pressure (CoP) as a way of identifying motor deficits. However, the optimal frequency range for assessing CoP variables and the effect of filtering on the relationships between anthropometric variables and CoP are unclear. The aim of this work is to show the relationship between anthropometric variables and different ways of filtering the CoP data. CoP was measured in 221 healthy volunteers using a KISTLER force plate in four different test conditions, both mono and bipedal. The results show no significant changes in the existing correlations of the anthropometric variable values over different filter frequencies between 10 Hz and 13 Hz. Therefore, the findings with regard to anthropometric influences on CoP, with a reasonable but less than ideal filtering of the data, can be applied to other study settings.

Obesity Impairs Functional Recovery of Older Stroke Patients with Possible Sarcopenia: A Retrospective Cohort Study

The functional prognosis of older patients with coexisting obesity and possible sarcopenia remains uncertain following acute stroke. This study aimed to determine whether coexisting obesity independently affects activities of daily living (ADL) and balance ability at discharge in older patients with possible sarcopenia admitted to a stroke rehabilitation ward. A total of 111 patients aged 65 years or older with possible sarcopenia were included, of whom 36 (32.4%) had coexisting obesity. Possible sarcopenia was diagnosed based on low handgrip strength without reduced muscle mass, while obesity was determined by body fat percentage (≥25% for men, ≥30% for women). Multivariate linear regression analysis revealed that compared to patients without obesity, patients with obesity had a higher likelihood of poorer ADL (b = -0.169; p = 0.02) and balance ability (b = -0.14; p = 0.04) performance at discharge following a 4-week period of inpatient rehabilitation. These findings suggest that obesity may be a modifiable risk factor in the rehabilitation of older patients with possible sarcopenia and should be considered in the assessment of decreased muscle strength.

Somatic characteristic, morphological asymmetry and postural stability of youth male canoeists compared to control. A cross-sectional study

OBJECTIVE

To determine the relationships between selected morphological characteristics and the level of body composition asymmetry with postural stability among canoeists and a control group.

METHODS

The sample consisted of 43 males (21 canoeists 21.8±3.29 years and 22 university students 21.7±1.32 years). Measurements included body height and weight. Segmental body composition analysis was assessed using the bioelectrical impedance by determining: fat mass (FM, kg, %), fat-free mass (FFM, kg) and predicted muscle mass (PMM, kg). Postural stability was tested using the BIODEX Balance System. Anterior-posterior stability index (APSI), medial-lateral stability index (MLSI) and overall stability index (OSI) were calculated.

RESULTS

Our findings suggest that the canoeists had statistically lower level of fatty tissue compared to controls. There was a statistically important difference between groups in lower limb FM (% and kg). In both groups morphological asymmetry was observed, but in most cases-in athletes. Asymmetries between right and left arms appeared in all parameters, while asymmetries between right and left legs were noted in all parameters except FM (kg). There were relationships between stature and body weight with postural stability in canoeists. Canoeists demonstrated better balance than controls, particularly in the APSI. For all stability indices, significant differences were observed between right and left legs across all participants.

CONCLUSIONS

Athletes, with larger asymmetries or poorer balance, require more attention to improve performance and reduce the risk of overload injury. Future studies needed to develop sport-specific level of morphofunctional asymmetry which would be optimal for sport results and health as well.

Postural balance ability and vertical jumping performance in female veteran volleyball athletes and non-athletes

Lifetime participation in sports is associated with improved components of physical conditioning. The main purpose was to cross-sectionally investigate postural balance and vertical jumping performance in athletes with different histories of sports participation and secondarily to examine the restriction of vision on balance ability. A final aim was to investigate possible associations between balance and jumping performance. We hypothesized higher balance and jumping performance in active veteran volleyball athletes compared to retired athletes and non-athletes, suggesting a positive effect of continuous systematic training in active veteran athletes. We also hypothesized greater negative effect of vision removal on balance in the veteran compared to non-athletes due to athletes' stronger reliance on visual information. Eighty-one healthy middle-aged women (mean (standard deviation) 50 (5) years) were assigned to three experimental groups, a retired (n = 39, recreationally active former athletes), an active (n = 27, training 2days/week x 1.5 h/session) veteran volleyball athletes' and a control group (n = 15, sedentary participants). Participants completed an assessment of single-legged quiet stance trials with either left or right leg with eyes open while standing barefoot on a force plate and two-legged trials with both eyes open or closed. They also executed a protocol of countermovement jumps. Statistical analyses included univariate and full factorial ANOVAs with group and vision as fixed and repeated-measures factors and simple linear regression analysis. In the single-legged balance task, solely the mediolateral sway range was greater for the active (p < 0.001) and retired athletes (p < 0.001) compared to non-athletes, whereas in the two-legged stance, no differences among groups were found (p > 0.05). Restriction of vision deteriorated balance performance similarly in the three groups as a significant vision effect was found for path length (p < 0.001), anteroposterior (p < 0.001) and mediolateral sway (p < 0.05). The active and retired athletes had significantly (p < 0.001) greater height, mean and maximal power in countermovement jump compared to non-athletes. Results showed weak associations (average R² = 9.5%) of balance with jumping performance only in the veteran volleyball athletes' group. Overall, the findings showed that retired volleyball athletes exhibited similar balance ability and vertical jumping performance as the active ones, suggesting a positive impact of prior experience in systematic training.

The Rehabilitation Program Improves Balance Control in Children with Excessive Body Weight and Flat Feet by Activating the Intrinsic Muscles of the Foot: A Preliminary Study

BACKGROUND

determining the appropriate rehabilitation protocol is essential to influence the correction of flat feet, e.g., by activating the intrinsic muscles of the foot. Therefore, this study aimed to determine the impact of the exercises activating the intrinsic foot muscles for postural control in children with flat feet, with normal and excessive body weight.

METHODS

Fifty-four children aged 7 to 12 were enrolled in the research. Forty-five children were qualified for the final evaluation. Each child in the experimental group was demonstrated an appropriate technique for performing a short foot exercise without compensation by extrinsic muscle. The participants then performed a supervised short foot training session once a week and on other days of the week under the supervision of caregivers for 6 weeks. Flat feet were scored on the foot posture index scale. A postural test was evaluated with a Biodex balance system SD. Statistical significance in the foot posture index scale and postural test were evaluated using an analysis of variance (ANOVA) with Tukey's post-hoc test.

RESULTS

according to the six indices of the foot posture index scale, five indicators showed statistically significant improvement after rehabilitation. At the 8-12 platform mobility level, it was revealed that the excessive body weight group had significant improvements in the overall stability index and medio-lateral stability index, with eyes closed.

CONCLUSION

our results indicate that a 6-week rehabilitation program based on the activation of the intrinsic muscles of the foot resulted in an improvement in the foot position. This, in turn, affected balance control, especially in children with excess body weight in conditions of closed eyes.

Association between constitution, axiography, orthodontic cast analysis, and upper body posture in women aged 31 to 40 years

OBJECTIVE

Whether it is primarily the spine that reacts with pain to the negative consequences of everyday stress and possibly the temporomandibular system as a result (ascending chain), or whether incorrect stress in the dental area has an influence on body geometry (descending chain), is still a controversially discussed topic. The aim of this study is to investigate possible relationships between constitutional, axiographic, and dental parameters with upper body posture.

MATERIAL AND METHODS

A total of 106 subjectively healthy women between 31 and 40 years of age voluntarily participated in this study. Data collection was done by filling out a questionnaire with constitutional and anamnestic parameters and by evaluating orthodontic casts, axiographic measurements, and video raster stereographic measurements. These data were analyzed using correlations and group comparisons, with the significance level set at p ≤ 0.05.

RESULTS

Positive correlations were shown between the constitutional factors of body weight and BMI and the lumbar bending angle (p = 0.01), the kyphosis angle (p = 0.001), and lordosis angle (weight p = 0.05; BMI p = 0.03). In the cast analysis, regardless of the direction of the midline shift (left/right/none), a left lateral tilt can be seen which is greatest at 2.12° with a left midline shift. In addition, the elevated pelvic side correlates with the side of the displacement of the jaw, with the stronger manifestation being on the left side. With a vertical anterior bite in the normal range, the kyphosis angle is 48.09°, while with a deep bite, it is 60.92°, and with an open bite, it is 62.47°; thus, the group in the normal range differs significantly (p = 0.01) from the other two. The greater the protrusion, the smaller the sagittal plane angles (kyphosis angle, lumbar bending angle, each p = 0.03), and the more dorsal the posture (p = 0.04). The lordosis angle differs significantly (p = 0.001) between the group of subjects with a protrusion in the normal range (52.34°) and the group with an increased advancement of the mandible (41.79°).

CONCLUSION

There is a correlation between body weight, BMI, midline shift, and protrusion, as well as the vertical anterior step and upper body posture in women between 31 and 40 years of age. Interdisciplinary functional examinations of the temporomandibular musculature, and also sustained orthodontic treatment, can contribute to an improvement in upper body posture.

Overweight Impairs Postural Control of Female Night Workers

Objectives  To verify the relationships between sleep duration (Total Sleep Time - TST) and postural control of female night workers before and after shift. As well as, to verify if there is an influence of the body mass index (BMI) on the postural control of these female workers before and after shift. Methods  A total of 14 female night workers (mean age: 35.0 ± 7.7 years) were evaluated. An actigraph was placed on the wrist to evaluate the sleep-wake cycle. The body mass and height were measured, and BMI was calculated. Postural control was evaluated by means of a force platform, with eyes opened and eyes closed before and after the 12-hour workday. Results  There was an effect of the BMI on the velocity and the center of pressure path with eyes opened before ( t  = 2.55, p  = 0.02) and after ( t  = 4.10, p  < 0.01) night work. The BMI impaired the velocity and the center of pressure path with eyes closed before ( t  = 3.05, p  = 0.01; t  = 3.04, p  = 0.01) and after ( t  = 2.95, p  = 0.01; t  = 2.94, p  = 0.01) night work. Furthermore, high BMI is associated with female workers' postural sway ( p  < 0.05). Conclusion  Therefore, high BMI impairs the postural control of female night workers, indicating postural instability before and after night work.

Obstacle clearance performance in individuals with high body mass index

The objective of this study was to quantify performance in an obstacle clearance task among individuals with excess body weight or body mass index (BMI). Task performance was operationalized as the maximum obstacle height cleared, four duration measures of successful task completion and compensatory movements used in the process of task completion. Eighteen participants with a BMI exceeding 30 kg/m² completed a laboratory experiment that required stepping over seven lightweight obstacles. Obstacle heights were sequentially increased from 36 cm in 5 cm increments until participants were unsuccessful or unable to clear the obstacle up to 66 cm. Successful task completions decreased from 100% at an obstacle height of 36 cm to 66.1% at 66 cm. Higher obstacle heights were associated with significantly fewer task completions, longer leading and trailing leg stance and overall task duration, and more frequent use of compensatory movements for successful obstacle clearance. Cox PH regression was used to test the association between probability of obstacle clearance and normalized obstacle height adjusting for BMI, standing balance, and type of compensatory movement used, namely, hover and pivot motions involving the leg, and hands for bracing. The probability of successful task completion significantly decreased with increases in BMI (hazard ratio, HR = 1.14, 95% CI: 1.05-1.25), and increased with use of a leg pivot motion (HR = 0.30, 95% CI: 0.09-0.96) during task completion, after adjusting for standing balance and other types of compensatory movements. Overall, the results demonstrated that obstacle clearance performance is affected by an individual's BMI and the use of compensatory behaviors for regaining stability. The ability to recruit internal and external stabilization techniques could potentially serve as a clinical indicator of reduced fall risk and be the focus of fall prevention interventions. Implications for evaluating stability, fall risk, and identifying modifiable factors for fall prevention in the obese population are discussed.

Contribution of lower extremity muscles to center of mass acceleration during walking: Effect of body weight

Overweight or obesity is known to be associated with altered activations of lower extremity muscles. Such changes in muscular function may lead to the development of mobility impairments or joint diseases. However, little is known about how individual lower extremity muscles contribute to the whole-body center of mass (COM) control during walking and the effect of body weight. This study examined the contribution of individual lower extremity muscle force to the COM accelerations during walking in overweight and non-overweight individuals. Musculoskeletal simulations were performed for the stance phase of walking with data collected from 11 overweight and 13 non-overweight adults to estimate lower extremity muscle forces and their contributions to the COM acceleration. Mean time-series data from each parameter were compared between body size groups using Statistical Parametric Mapping. Compared to the non-overweight group, the overweight group revealed a greater gastrocnemius contribution to the mediolateral (p = 0.006) and vertical (p < 0.001) COM accelerations during mid-stance, and had a lower vastus contribution to the anteroposterior COM acceleration (p < 0.001) during pre-swing. Increased contributions from the large posterior calf muscles to the mediolateral COM acceleration may be related to efforts to alleviate COM sway in overweight individuals.

Factors associated with balance ability in Duchenne and Becker muscular dystrophies

BACKGROUND

Problems such as progressive muscle function loss, postural deteriorations, and contractures seen in patients with Duchenne and Becker muscular dystrophies (D/BMD) may affect children's balance ability, and impaired balance ability may lead to limitations in children's functional level.

RESEARCH QUESTION

What factors are associated with balance ability in children with D/BMD?

METHODS

Twenty participants with D/BMD were included in the study. Participants' ages were asked; height, body weight, and body mass index (BMI) were recorded. Children's functional level was assessed with the Motor Function Measurement-32 (MFM-32), Brooke and Vignos Scales. Muscle strength of hip flexion and extension, knee flexion and extension, and ankle dorsiflexion was measured with a handheld dynamometer. Balance measurements were performed using the Balance Master System. The relationship between balance and continuous independent variables was determined using Spearman's test.

RESULTS

The mean age of the participants was 8.57 ± 3.27 years. The balance abilities of children with BMD were better than those of children with DMD (p < 0.05). The balance diminished with age (p < 0.05), while there was a positive correlation between balance and weight, height, BMI (p < 0.05). There was a positive correlation between the balance and the MFM-32 total and subsection scores. Muscle strength was positively related to balance (p < 0.05).

SIGNIFICANCE

The results showed the balance ability in children with D/BMD was affected by age, height, weight, BMI, functional level, and muscle strength. Based on the results of this study, balance and strength training should be an integral part of the rehabilitation of children with D/BMD.

Postural instability in Parkinson's disease assessed with clinical "pull test" and standardized postural perturbations: effect of medication and body weight support

OBJECTIVE

This experiment tested if balance performance differed between a standardized treadmill surface perturbation task and a clinical pull test and was affected by medication or the presence of body weight support in people with Parkinson's disease (PD).

METHODS

Twenty-seven individuals were tested (14 PD in both ON- and OFF-medication states). Clinical pull test and rapid forward (backward fall) translations of the support surface were applied to induce postural reactions requiring at least 1 step to restore balance. The effects of pull type (clinical vs. treadmill), partial bodyweight support (0 vs 20% body weight) and group (control, PD ON-meds and PD OFF-meds) on reactive stepping as well as practice/learning effect were examined. The number of steps taken and the first step duration were entered in linear repeated-measures mixed-effect models separately.

RESULTS

The effects of pull type, group, and bodyweight support were all significant in both metrics, as was ON- vs. OFF-medication. A significant interaction term (group x pull type) was found in the first step duration, showing that the group difference was greater in treadmill compared to the clinical pull test. A significant practice effect was also observed within and across testing sessions.

CONCLUSIONS

A standardized treadmill perturbation performed slightly better than the classical pull test in distinguishing between groups, and partial weight support did not substantially degrade the test's performance to detect the balance deficits in people with PD.

The Influence of Weight Loss in Postural Control in Women Undergoing Sleeve Gastrectomy

BACKGROUND

Bariatric surgery is the most effective procedure for obesity management, with a greater body weight loss and the remission of several diseases. The aim of this study was to analyze the relationships between the anthropometric profile and postural control outcomes in a group of obese adult women, and the effect of bariatric surgery on postural control.

METHODS

eighty-eight women candidates for bariatric surgery were recruited. Static balance was measured with the ARGO stabilometric platform under two conditions: open eyes (OE) and closed eyes (CE).

RESULTS

Multiple linear regression indicated BMI as the first predictor for postural control in all parameters, except for APO in open eyes, predicted mainly by height. Changes in body weight and BMI showed no statistically significant correlations with modification of postural control parameters (OE), while they appeared to exert an influence under closed eyes conditions.

CONCLUSIONS

Before surgery, obese patients with a higher BMI showed a better postural control. After surgery, the sway path and antero-posterior oscillation improved under open eyes conditions, while the magnitude of weight loss was negatively correlated with differences in postural control.

One-year prevalence and clinical characteristics in chronic dizziness: The 2019-2020 Korean National Health and Nutrition Examination Survey

INTRODUCTION

In this cross-sectional study, we investigated the 1-year prevalence and related factors in the general population with an experience of chronic dizziness.

METHODS

This study analyzed persons (n = 5,163) who respond to dizziness and nutrition questionnaire from participant of Korean National Health and Nutrition Examination Survey (KNHANES, 2019-2020).

RESULTS

Of individuals over 40 years, 25.3% of the general population (61.6% females) reported either dizziness or imbalance for the past year. Moreover, 4.8% of the patients reported they suffered from chronic dizziness or imbalance for more than 3 months. In multiple regression analysis, patients with chronic dizziness were older, females, had lower body mass index (BMI), had stress awareness, and had a history of tinnitus within 1 year (>5 min per episode). Relative to normal body weight, both overweight and mild obesity (obesity stages 1 and 2) were associated with a significantly lower risk of chronic dizziness. Overweight, obesity stage 1, and obesity stage 2 had odds ratios of 0.549 [95% confidence interval (CI), 0.332-0.910], 0.445 (95% CI, 0.273-0.727), and 0.234 (95% CI, 0.070-0.779), respectively.

CONCLUSIONS

In this study, the prevalence of chronic dizziness in the general population was 4.8%. Our study demonstrated that overweight and mild obesity were independently associated with a lower risk of chronic dizziness in adults for the past year. Therefore, the optimal BMI for patients with dizziness should be defined and managed according to an integrated care pathway.

Changes in dynamic balance control in adults with obesity across walking speeds

Adults with obesity have gait instability, leading to increased fall risks and decreased physical activity. Whole-body angular momentum (WBAM) is regulated over a gait cycle, essential to avoid a fall. However, how obese adults regulate WBAM during walking is unknown. The current study investigated changes in WBAM about the body's center of mass (COM) during walking in obese and non-obese adults across different walking speeds. Twenty-eight young adults with obesity and normal weight walked barefoot at a fixed walking speed (FWS, 1.25 m/s) and at five different speeds based on their preferred walking speed (PWS): 50, 75, 100, 125, and 150 % of PWS. Adults with obesity walked slower with shorter step length, wider step width, and longer double support time (p < 0.01). The ranges of frontal- and transverse-plane WBAM were greater in obese adults (p < 0.01). We also found that the range of frontal-plane WBAM did not significantly change with walking speed (p > 0.05), while the range of transverse-plane WBAM increased with walking speed (p < 0.01). The ranges of frontal- and transverse-plane WBAM increased with the mediolateral ground reaction force and mediolateral moment arm (p < 0.01), which may be most affected by lateral foot placement relative to the body's COM. Our findings suggest that controlling mediolateral stability during walking is more challenging in obese adults, independent of their slow walking speed. Understanding whole-body rotational dynamics observed in obese walking provides an insight into the biomechanical link between obesity and gait instability, which may help find a way to reduce fall risks and increase physical activity.

The Effect of Different Body Mass Index Levels on Static and Dynamic Postural Balance Performance in Adults

Background and Purpose: It was aimed to examine the static and dynamic postural balance performance in adults with different Body Mass Index (BMI) levels. Methods: Study was conducted in Üsküdar Diabetes and Obesity Treatment Center between September and October 2021. Participants were divided into 5 groups according to BMI scores: normal-weight, overweight, 1st degree obese, 2nd degree obese, and 3rd degree obese. The static and dynamic balance performance of participants were assessed by the Limits of Stability (LOS) and modified Clinical Test of Sensory Integration of Balance (m-CTSIB) tests. Results: For LOS parameters, there was a significant difference between groups in reaction time scores only for the backward direction (p

The effect of diabetic retinopathy on standing posture during optic flow stimulation

BACKGROUND

Diabetic retinopathy is a principal cause of visual damage and blindness, in which laser treatment offers proven therapy. The progressive degeneration of the retina, secondary to diabetes, is believed to cause postural instability although this is not well documented. The aim of this research was to assess how optic flow stimuli contribute to the control of stance in people with impaired retinal functions.

RESEARCH QUESTION

Does the different retinal functionality correspond to different specific patterns of movements and muscles recruitment?

METHODS

Postural mechanisms and motor strategies were measured by testing subjects in quiet stance on a force platform with surface electromyography under different optic flow stimulations. Root mean square values of the center of pressure time-varying signals and normalized EMG values were used to evaluate the postural sway.

RESULTS

People with diabetic retinopathy, and to a greater extent laser group, were more unstable than healthy subjects. The greater amplitude of the body sway observed in the retinopathy group, and especially in the laser group, could be an expression of the difficulty for this population in processing this kind of visual information.

SIGNIFICANCE

The increase in muscle activity indicates that there are musculoskeletal and postural changes in the lower limb musculature with increasing severity of diabetic retinopathy. An impaired retinal function might negatively affect postural control in a way that is dependent on the severity of retinal damage.

Kinematic synergies in over-ground slip recovery outcomes: Distinct strategies or a single strategy?

BACKGROUND

After experiencing an unexpected slip perturbation, individuals' behavioral performance can be classified into three categories: recovery, feet-forward fall, and split fall. Researchers are uncertain whether these differences in slip outcomes are due to distinct strategies or part of a single strategy.

RESEARCH QUESTION

Whether older adults with different behavioral outcomes during their novel slip have different kinematic synergies?

METHODS

The kinematic synergies were extracted from segment angles in 87 participants using principal component analysis (PCA). The first two principal components (PC1 and PC2) in pre-slip, early-reactive, and late-reactive phases were compared across different slip outcomes.

RESULTS

Results showed that the kinematic synergies in pre-slip and early-reactive phases are highly consistent among the three outcomes (recovery, split fall, and feet-forward fall). For the late-reactive phase, both split falls and feet-forward falls showed different kinematics synergies from recoveries.

SIGNIFICANCE

Our findings indicated that a single strategy might be used for different slip outcomes in the pre-slip and early-reactive phases, while distinct strategies were used by fallers compared to recovered individuals. Specifically, larger trunk flexion in pre-slip phase, larger knee flexion and plantar flexion of the slipping limb in both early-reactive and late-reactive phase, and larger knee extension of the recovery limb in late-reactive phase would lower the fall risk. This study would help to assess the vulnerabilities in control strategy, according to which individualized treatment could be provided to reduce predisposition to specific types of falls.

The effect of body mass reduction on functional stability in young obese women

Functional stability is necessary for everyday activities. The studies have indicated the deterioration of functional stability during standing in the obese adults. This study aimed to determine whether the 3-month weight-loss program that resulted in body mass reduction equal to or greater than 5% of the initial body mass would improve functional stability in young obese women. For the purpose of this study, the data of 30 females were included. Their mean age was 35.8 ± 9.2. The women performed the anterior limit of stability test on the force platform twice: before and after weight-loss program. Their BMI at two sessions was 36.1 ± 5.1 and 32.3 ± 5, respectively. After the weight loss program, the COP velocities were increased in both phases of the anterior limit of stability test: the dynamic transition from standing to maximal forward-leaning and the maintenance of maximal forward-leaning position (p < 0.05). No significant changes in the values of the COP parameters were found in the eyes-closed trial (p > 0.05). The results suggest that body mass reduction in young obese women led to improved mobility and postural control when visual cuing was available. The longer-lasting weight-loss program might be necessary to observe this effect under visual deprivation conditions. Body mass should be reduced in obese patients to improve their mobility and functional stability; it may prevent unexpected falls.

Gait Slip-Induced Fall-Type Assessment Based on Regular Gait Characteristics in Older Adults

Older adults could experience split falls or feet-forward falls following an unexpected slip in gait due to different neuromuscular vulnerabilities, and different intervention strategies would be required for each type of faller. Thus, this study aimed to investigate the key factors affecting the fall types based on regular gait pattern. A total of 105 healthy older adults who experienced a laboratory-induced slip and fall were included. Their natural walking trial immediately prior to the novel slip trial was analyzed. To identify the factors related to fall type, gait characteristics and demographic factors were determined using univariate logistic regression, and then stepwise logistic regression was conducted to assess the slip-induced fall type based on these factors. The best fall-type prediction model involves gait speed and recovery foot angular velocity, which could predict 70.5% of feet-forward falls and 86.9% of split falls. Body mass index was also a crucial fall-type prediction with an overall prediction accuracy of 70.5%. Along with gait parameters, 84.1% of feet-forward falls and 78.7% of split falls could be predicted. The findings in this study revealed the determinators related to fall types, which enhances our knowledge of the mechanism associated to slip-induced fall and would be helpful for the development of tailored interventions for slip-induced fall prevention.

Effects of a Multicomponent Exercise Training Program on Balance Following Bariatric Surgery

Patients who undergo bariatric surgery (BS) have an increased risk of falls. Our aim was to determine if a multicomponent exercise intervention after BS improves balance. Eighty-four patients with obesity enrolled for BS were recruited and 1 month after BS randomly allocated to a control (CG; standard medical care) or exercise group (EG; exercise plus standard medical care) consisting of a supervised multicomponent training program (3d/week; 75 min/session; 5 months). Anthropometry, lower limb muscle strength (isokinetic dynamometer), vitamin D (ELISA) and balance in bipedal stance (force platform) were assessed pre-BS, 1 month and 6 months post-BS. One month post-BS, significant balance improvements were observed, namely in antero-posterior center of gravity (CoG) displacement and velocity, and medio-lateral and total CoG velocity. Between 1- and 6-months post-BS, improvements in balance were observed only in the EG, with a significant treatment effect on CoG displacement area and antero-posterior CoG displacement. No significant differences were observed between EG and CG over time in any of the anthropometric, muscle strength, and vitamin D variables assayed. In conclusion, a multicomponent exercise intervention program improves some balance parameters in patients with severe obesity following BS and therefore should be part of post-BS follow-up care as a potential strategy to reduce falls and associated injuries.

Mental Fatigue Impairs Postural Stability in Older Adults

Purpose: Postural instability can increase the risk of a fall in older adults. In this study, the impact of mental fatigue on postural stability among healthy older adults was investigated. Method: Participants were randomly divided into two groups: experimental and control groups. Postural stability of all participants was tested using the Biodex Balance System (BBS) before and immediately after watching a 30-min documentary program (control group) or completing a 30-min Stroop task (experimental group). Subjective ratings of mental fatigue were measured before and after the Stroop task or watching documentary program. Results: The results indicated that experimental group revealed higher stability scores in the posttest compared to pretest (P ≤ 0.001). However, there were no significant differences for BBS scores between pre and posttest in control group (P = .688). In addition, posttest of subjective ratings of mental fatigue was significantly different between experimental and control groups. Finally, there was also evidence of an association between Visual analog scale and BBS scores in the experimental group (rs = 0.712, P = .002). Conclusions: Mental fatigue caused by Stroop task had a negative impact on postural stability in older adults. This may be due to reduction in attentional resources that was caused by mental fatigue. Thus, mental fatigue could be considered as a risk factor for increased risk of falls in older adults.

Time Course and Mechanisms Underlying Standing Balance Recovery Early After Stroke: Design of a Prospective Cohort Study With Repeated Measurements

Introduction

Although most stroke survivors show some spontaneous neurological recovery from motor impairments of the most-affected leg, the contribution of this leg to standing balance control remains often poor. Consequently, it is unclear how spontaneous processes of neurological recovery contributes to early improvements in standing balance.

Objective

We aim to investigate (1) the time course of recovery of quiet stance balance control in the first 12 weeks poststroke and (2) how clinically observed improvements of lower limb motor impairments longitudinally relate to this limb's relative contribution to balance control.

Methods and Analysis

In this prospective longitudinal study, a cohort of 60 adults will be recruited within the first 3 weeks after a first-ever hemispheric stroke and mild-to-severe motor impairments. Individual recovery trajectories will be investigated by means of repeated measurements scheduled at 3, 5, 8, and 12 weeks poststroke. The Fugl-Meyer Motor Assessment and Motricity Index of the lower limb serve as clinical measures of motor impairments at the hemiplegic side. As soon as subjects are able to stand independently, bilateral posturography during quietly standing will be measured. First, the obtained center-of-pressure (COP) trajectories at each foot will be used for synchronization and contribution measures that establish (a-)symmetries between lower limbs. Second, the COP underneath both feet combined will be used to estimate overall stability. Random coefficient analyses will be used to model time-dependent changes in these measures and, subsequently, a hybrid model will be used to investigate longitudinal associations with improved motor impairments.

Discussion

The current study aims to investigate how stroke survivors "re-learn" to maintain standing balance as an integral part of daily life activities. The knowledge gained through this study may contribute to recommending treatment strategies for early stroke rehabilitation targeting behavioral restitution of the most-affected leg or learning to compensate with the less-affected leg.

Influence of footwear on postural sway: A systematic review and meta-analysis on barefoot and shod bipedal static posturography in patients and healthy subjects

BACKGROUND

Bipedal static posturography is widely used to assess postural control. However, standardized methods and evidence on the influence of footwear on balance in comparison to barefoot stance is sparse.

RESEARCH QUESTIONS

Is bipedal static posturography applied in a standardized way with respect to demographics and the experimental set-up (systematic review)? Does habitual footwear influence postural control in comparison to barefoot condition during bipedal static posturography in adult patients and healthy subjects (meta-analysis)?

METHODS

For this systematic review and meta-analysis, a comprehensive follow-up literature search was conducted from March 2009 until January 2020 according to the PRISMA guidelines. Original, research articles reporting on bipedal, unsupported, static posturography in adults (≥18 years) were included according to inclusion criteria (age, sex, height, weight, duration, repetitions, visual/foot condition, sampling frequency). Studies comparing habitual footwear with barefoot condition during bipedal static posturography were included for the meta-analysis. Center of pressure parameters (sway velocity, range, root mean square, paths lengths) with subjects having eyes closed (EC) or open (EO) were analyzed using random effects models.

RESULTS

For this systematic review and meta-analysis, 207 and eight out of 5189 studies with 12'341 and 156 subjects, respectively, were eligible. Most studies (89%) reported barefoot, 5% shod, and 6% barefoot and shod measurements. Less than half of studies (44%) included patients of which the minority (13%) suffered from neurological disease. Sway velocity in the anterior-posterior direction was higher in habitual shoes compared to barefoot with EC (SMD: 1.08; 95% CI: 0.68-1.48; p < 0.01; I² = 0%), with EO (SMD: 0.68; 95% CI: 0.11-1.26; p = 0.02; I² = 1%), and in the medio-lateral direction with EC (SMD: 1.30; 95% CI: 0.76-1.85, p < 0.01; I² = 37%).

SIGNIFICANCE

Methodical heterogeneity of bipedal static posturography hampers studies' comparability. Thus, we provide a standardized approach to increase knowledge whether habitual footwear decrease postural control in comparison to barefoot stance.

Bariatric surgery and exercise: A pilot study on postural stability in obese individuals

This study aimed to analyze the changes in postural stability of individuals with obesity after bariatric surgery, and the effect of three months of regular exercise on the static postural stability. Twenty-two subjects (7 females and 15 males) aged 31 to 68 years (Body mass index 35-55 kg.m-2) completed the study. Participants were divided into two groups: one group participated in an exercise program after the bariatric surgery (n = 10; age 48.9 ± 7.5 years; Body mass index 42 ± 5.6 kg.m-2) while the second group did not exercise at all after bariatric surgery (n = 12; age 44.7 ± 13.6 years, Body mass index 42.6 ± 6.0 kg.m-2). Static postural stability was measured using a Tekscan MobileMat pressure plate before and 4 months after the bariatric surgery. The exercise program included exercising three times a week including: one hour of strengthening, one hour of aerobic group exercise and at least one session of individual exercise at home. There were no significant differences in Center of force sway, Center of force ranges and average speed before and 4 months after bariatric surgery. Also, no effect of exercise was found. Post-pre differences of some parameters were negatively related to age (r from-0.46 to-0.72). Further studies are needed to explore this topic in depth.

Predicting Ability of Dynamic Balance in Construction Workers Based on Demographic Information and Anthropometric Dimensions

Background

Difficulties in walking and balance are risk factors for falling. This study aimed to predict dynamic balance based on demographic information and anthropometric dimensions in construction workers.

Methods

This descriptive-analytical study was conducted on 114 construction workers in 2020. First, the construction workers were asked to complete the demographic questionnaire determined in order to be included in the study. Then anthropometric dimensions were measured. The dynamic balance of participants was also assessed using the Y Balance test kit. Dynamic balance prediction was performed based on demographic information and anthropometric dimensions using multiple linear regression with SPSS software version 25.

Results

The highest average normalized reach distances of YBT were in the anterior direction and were 92.23 ± 12.43% and 92.28 ± 9.26% for right and left foot, respectively. Both maximal and average normalized composite reach in the YBT in each leg were negatively correlated with leg length and navicular drop and positively correlated with the ratio of sitting height to leg length. In addition, multiple linear regressions showed that age, navicular drop, leg length, and foot surface could predict 23% of the variance in YBT average normalized composite reach of the right leg, and age, navicular drop, and leg length could predict 21% of that in the left leg among construction workers.

Conclusion

Approximately one-fifth of the variability in the normalized composite reach of dynamic balance reach among construction workers using method YBT can be predicted by variables age, navicular drop, leg length, and foot surface.

Relationships between Height, Mass, Body Mass Index, and Trunk Muscle Activation during Seated Whole-Body Vibration Exposure

Operators of heavy equipment are often exposed to high levels of whole-body vibration (WBV), which has been associated with a variety of adverse health outcomes. Although anthropometric factors are known to impact vibration dose and risk of low back pain, studies have yet to investigate the influence of anthropometric factors on muscle activation during WBV exposure. This study quantified the relationships between muscle activation, vibration frequency, body mass, body mass index (BMI), and height both pre- and post-fatigue. Muscle activation of the external oblique (EO), internal oblique (IO), lumbar erector spinae (LE) and thoracic erector spinae (TE) were quantified using surface electromyography. Results indicate increased activation with increased mass, BMI, and frequency for the LE, TE, and IO, which may be a result of increased activation to stabilize the spine. Decreased muscle activation with increased height was seen in the TE, IO, and pre-fatigue EO, which could indicate higher risk for low back injury since height is associated with increased forces on the spine. This may contribute to the association between increased low back pain incidence and increased height. Results suggest that ISO 2631-1 health guidance should incorporate anthropometric factors, as these may influence muscle activation and back injury risk.

Prediction of fall risk among community-dwelling older adults using a wearable system

Falls are among the most common cause of decreased mobility and independence in older adults and rank as one of the most severe public health problems with frequent fatal consequences. In the present study, gait characteristics from 171 community-dwelling older adults were evaluated to determine their predictive ability for future falls using a wearable system. Participants wore a wearable sensor (inertial measurement unit, IMU) affixed to the sternum and performed a 10-m walking test. Measures of gait variability, complexity, and smoothness were extracted from each participant, and prospective fall incidence was evaluated over the following 6-months. Gait parameters were refined to better represent features for a random forest classifier for the fall-risk classification utilizing three experiments. The results show that the best-trained model for faller classification used both linear and nonlinear gait parameters and achieved an overall 81.6 ± 0.7% accuracy, 86.7 ± 0.5% sensitivity, 80.3 ± 0.2% specificity in the blind test. These findings augment the wearable sensor's potential as an ambulatory fall risk identification tool in community-dwelling settings. Furthermore, they highlight the importance of gait features that rely less on event detection methods, and more on time series analysis techniques. Fall prevention is a critical component in older individuals’ healthcare, and simple models based on gait-related tasks and a wearable IMU sensor can determine the risk of future falls.

Effect of telerehabilitation applied during COVID-19 isolation period on physical fitness and quality of life in overweight and obese individuals

Background/objectives

The aim of the study was to examine the effects of exercise training through telerehabilitation applied during COVID-19 isolation period on overweight and obese individuals on physical fitness and quality of life.

Subjects/methods

In our study, 41 participants between the ages of 18–65 years and whose BMI values were 25 kg/m² and above were randomly divided into two groups as telerehabilitation group (n: 21) and control group (n: 20). Exercise training applied to the telerehabilitation group with remote live connection included warm-up exercises, trunk stabilization exercises and breathing exercises under the supervision of a physiotherapist for 6 weeks, 3 days in a week. The control group was only informed about the importance of exercise for one session and evaluated at baseline and after 6 weeks. The physical fitness levels of individuals was assessed by Senior Fitness Test protocol and quality of life by Short Form-36.

Results

As a result of the study, statistically significant improvements were obtained in all parameters of physical fitness, quality of life in the telerehabilitation group (p < 0.05). In the difference values of the two groups, all parameters of physical fitness and quality of life were observed that there were statistically significant differences in favor of telerehabilitation group (p < 0.05).

Conclusions

As a result, it was found that exercise training applied through telerehabilitation during the COVID-19 pandemic process was an effective, safe and viable approach in overweight and obese individuals. In the future, studies investigating the long-term effectiveness of telerehabilitation in this population are needed.

Association between Anthropometric Variables, Sex, and Visual Biofeedback in Dynamic Postural Control Assessed on a Computerized Wobble Board

Anthropometrics and sex influence balance performances, and visual information can change anthropometrics’ relation and the postural sway. Therefore, the aim of the present study was to evaluate the effect of anthropometric characteristics, sex, and visual biofeedback and/or their interaction on a computerized wobble board. Twenty-seven (14 females, 13 males) young adults performed three 30-s double leg stance trials on a wobble board during two conditions: with visual and without visual biofeedback. Visual biofeedback improved (p = 0.010) balance on a wobble board with respect to the condition without visual biofeedback. Regardless of sex, no differences between conditions were found (p = 0.088). When investigating the effect of anthropometrics variables, sex, and their interactions on conditions, a significant main effect of the lower limb/height ratio, sex, and their interaction on the condition without visual biofeedback was found (p = 0.0008; R2 = 0.57). For the visual biofeedback condition, significant effects for sex and body mass (p = 0.0012; R2 = 0.43) and sex and whole-body moment of inertia (p = 0.0030; R2 = 0.39) were found. Results from the present study showed (1) visual biofeedback improved wobble board balance performance; (2) a significant main effect of lower limb/height ratio, sex, and their interaction on the wobble board performances without visual biofeedback emerged; (3) significant effects were found for sex and body mass and sex and moment of inertia in the visual biofeedback condition. Findings from the present study could have an impact on training and evaluations protocols, especially when several populations such as children, athletes, older adults and people with balance disorders are involved.

Relation of Physical Activity Level to Postural Balance in Obese and Overweight Spanish Adult Males: A Cross-Sectional Study

The aim of this study was to analyze the influence of physical activity level on postural control in obese and overweight Spanish adult males. Forty-three males aged between 25 and 60 years old were included. Anthropometric, body composition, and physical activity variables were assessed, and postural control was evaluated using the Sensory Organization Test. No correlation was found between the level of physical activity and postural control, assessed by the Sensory Organization Test within the whole sample. However, within the group with a higher total fat mass percentage, non-sedentary individuals presented improved scores on the somatosensory organization test when compared to sedentary individuals (96.9 ± 1.8 vs. 95.4 ± 1.2; p < 0.05) and poorer scores on the composite equilibrium score (73.4 ± 7.2 vs. 79.2 ± 6.9; p < 0.05). The altered integration of somatosensory inputs most likely affects the tuning, sequencing, and execution of balance strategies in sedentary men with a high total fat mass percentage.