Effects of 7-Day Ketone Ingestion and a Physiological Workload on Postural Stability, Cognitive, and Muscular Exertion Measures in Professional Firefighters

Background: Postural stability and cognitive performance are challenged in firefighters. The purpose of this investigation was to examine the impact of 7-day ketone supplementation on postural stability, cognitive performance, and muscular activation before and after a physiological workload. Methods: Nine professional firefighters completed two experimental sessions (pre- and post-workload) in a counterbalanced, double-blind design. Participants ingested either a ketone salt (KS) or placebo (PLA) daily for seven days, and had an eighth ingestion 30 min prior to testing. Each experimental testing consisted of maximal voluntary contractions (MVIC) for four muscles (knee flexors—BF, extensor—VM, ankle dorsiflexors—TA, and plantar flexors—MG) using electromyography and postural stability testing (eyes open (EO), eyes closed (EC), and eyes open-dual-task using a FitLight™ system (EOT)), before (pre-workload) and after (post-workload) a simulated physiological workload. The workload consisted of 35 min steady state exercise at 60% of peak oxygen consumption wearing firefighter personal protective equipment (PPE). Results: Significant differences were limited to time effects (pre-workload vs. post-workload), with no differences between groups (KS vs. PLA). Significantly lower muscle activity in VM, TA, and MG during MVIC, greater postural sway and muscle activity in BF during EC and EOT, and slower response time during EOT were evident post-workload. Conclusions: A 7-day ketone supplementation does not impact postural stability, muscle activity, and cognitive tasks, but a fatiguing workload causes significant performance reduction.

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Dual-Tasking Effects on Dynamic Postural Stability in Athletes With and Without Anterior Cruciate Ligament Reconstruction

Journal of Sport Rehabilitation ◽

10.1123/jsr.2015-0012 ◽

2016 ◽

Vol 25 (4) ◽

pp. 324-329 ◽

Cited By ~ 8

Author(s):

Shahrzad Mohammadi-Rad ◽

Mahyar Salavati ◽

Ismail Ebrahimi-Takamjani ◽

Behnam Akhbari ◽

Shiva Sherafat ◽

...

Keyword(s):

Cognitive Performance ◽

Postural Stability ◽

Cruciate Ligament ◽

Stability Index ◽

Support Surface ◽

Dual Tasking ◽

Eyes Closed ◽

Error Ratio ◽

Eyes Open ◽

Anterior Cruciate

Purpose:To compare the effect of dual tasking on postural stability between patients with anterior cruciate ligament reconstruction (ACL-R) and healthy controls.Methods:Single-limb postural stability was assessed in 17 athletes with ACL-R and 17 healthy matched athletes while standing on a Biodex Balance System platform in 4 conditions: stability level of 8 (ie, more-stable support surface) with eyes open, stability level of 8 with eyes closed, stability level of 6 (ie, less-stable support surface) with eyes open, and stability level of 6 with eyes closed. Postural-stability tasks were performed with and without auditory Stroop task. The anteroposterior stability index (APSI), mediolateral stability index (MLSI), and overall stability index (OSI) as measures of postural performance, as well as reaction time and error ratio as measures of cognitive performance, were recorded.Results:Dual-tasking effect on postural stability was not significantly different between the groups in 3 postural conditions. Only in level 6 with eyes open, for APSI and OSI, patients with ACL-R showed lower postural stability under the dual-task condition. However, patients showed poorer performance on both reaction time and error ratio in all postural conditions.Conclusions:The patients with ACL-R appeared to sacrifice their cognitive performance to optimize their performance on postural stability. This posture-first strategy was reflected by a more pronounced effect of dual tasking on the auditory Stroop task than the postural-stability task. In situations where maintenance of posture is challenging, giving priority to the postural task at the expense of cognitive performance can ensure safety from balance loss.

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Muscle Activity during Postural Stability Tasks: Role of Military Footwear and Load Carriage

Safety ◽

10.3390/safety6030035 ◽

2020 ◽

Vol 6 (3) ◽

pp. 35

Author(s):

Sachini N.K. Kodithuwakku Arachchige ◽

Harish Chander ◽

Alana J. Turner ◽

Samuel J. Wilson ◽

Jeffrey D. Simpson ◽

...

Keyword(s):

Postural Control ◽

Muscle Activity ◽

Repeated Measures ◽

Postural Stability ◽

Load Carriage ◽

Plantar Flexors ◽

Extrinsic Factors ◽

Lower Extremity Muscle ◽

Design Characteristics ◽

The Impact

Decrements to postural control manifest as an increase in muscle activity, indicating continuous attempts to maintain body equilibrium and postural stability. Extrinsic factors such as footwear, and intrinsic factors such as muscle fatigue, can affect postural stability. The purpose of this study was to analyze the impact of two types of military footwear and a military-type load-carrying task on lower extremity muscle activity during various postural stability tasks. Sixteen males’ (age: 26.63 ± 3.93 years; mass: 87 ± 12.4 kg; height: 178.04 ± 6.2 cm) muscle activity from knee flexors, extensors, ankle dorsiflexors, and plantar flexors were measured using electromyography in standard (STD) and minimalist (MIN) military footwear, before (PRE) and after (POST) a simulated workload during sensory organization and motor control tests on the Neurocom EquitestTM. Mean muscle activity was analyzed using 2 (footwear) × 2 (time) repeated measures ANOVA with an alpha level of 0.05. Results revealed a requirement of significantly greater muscle activity in POST and STD. MIN demonstrated lesser balance decrements POST workload, which could be attributed to its design characteristics. Results will help in suggesting footwear design characteristics to minimize muscular exertion while eliciting better postural control, and to prevent postural instability due to overexertion in military personnel.

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The Influence of Proprioceptive Training with the Use of Virtual Reality on Postural Stability of Workers Working at Height

Sensors ◽

10.3390/s20133731 ◽

2020 ◽

Vol 20 (13) ◽

pp. 3731

Author(s):

Magdalena Cyma-Wejchenig ◽

Jacek Tarnas ◽

Katarzyna Marciniak ◽

Rafał Stemplewski

Keyword(s):

Virtual Reality ◽

Dual Task ◽

Postural Stability ◽

Center Of Pressure ◽

Force Plate ◽

Control Group ◽

Eyes Closed ◽

Proprioceptive Training ◽

Eyes Open ◽

The Impact

The aim of the study was to assess the impact of proprioceptive training with the use of virtual reality (VR) on the level of postural stability of high–altitude workers. Twenty-one men working at height were randomly assigned to the experimental group (EG) with training (n = 10) and control group (CG) without training (n = 11). Path length of the displacement of the center of pressure (COP) signal and its components in the anteroposterior and medial–lateral directions were measured with use of an AccuGaitTM force plate before and after intervention (6 weeks, 2 sessions × 30 min a week). Tests were performed at two different platform heights, with or without eyes open and with or without a dual task. Two–way ANOVA revealed statistically significant interaction effects for low–high threat, eyes open-eyes closed, and single task-dual task. Post-training values of average COP length were significantly lower in the EG than before training for all analyzed parameters. Based on these results, it can be concluded that the use of proprioceptive training with use of VR can support, or even replace, traditional methods of balance training.

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Gait Stability Measurement by Using Average Entropy

Entropy ◽

10.3390/e23040412 ◽

2021 ◽

Vol 23 (4) ◽

pp. 412

Author(s):

Han-Ping Huang ◽

Chang Francis Hsu ◽

Yi-Chih Mao ◽

Long Hsu ◽

Sien Chi

Keyword(s):

Postural Stability ◽

Multiscale Entropy ◽

Gait Stability ◽

Eyes Closed ◽

Stride Interval ◽

Step Interval ◽

Stability Measurement ◽

Eyes Open ◽

Two Measures ◽

Better Than

Gait stability has been measured by using many entropy-based methods. However, the relation between the entropy values and gait stability is worth further investigation. A research reported that average entropy (AE), a measure of disorder, could measure the static standing postural stability better than multiscale entropy and entropy of entropy (EoE), two measures of complexity. This study tested the validity of AE in gait stability measurement from the viewpoint of the disorder. For comparison, another five disorders, the EoE, and two traditional metrics methods were, respectively, used to measure the degrees of disorder and complexity of 10 step interval (SPI) and 79 stride interval (SI) time series, individually. As a result, every one of the 10 participants exhibited a relatively high AE value of the SPI when walking with eyes closed and a relatively low AE value when walking with eyes open. Most of the AE values of the SI of the 53 diseased subjects were greater than those of the 26 healthy subjects. A maximal overall accuracy of AE in differentiating the healthy from the diseased was 91.1%. Similar features also exists on those 5 disorder measurements but do not exist on the EoE values. Nevertheless, the EoE versus AE plot of the SI also exhibits an inverted U relation, consistent with the hypothesis for physiologic signals.

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Role of Occupational Footwear and Prolonged Walking on Lower Extremity Muscle Activation during Maximal Exertions and Postural Stability Tasks

Biomechanics ◽

10.3390/biomechanics1020017 ◽

2021 ◽

Vol 1 (2) ◽

pp. 202-213

Author(s):

Harish Chander ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Alana J. Turner ◽

Reuben F. Burch V ◽

Adam C. Knight ◽

...

Keyword(s):

Lower Extremity ◽

Muscle Activity ◽

Repeated Measures ◽

Postural Stability ◽

Muscle Activation ◽

Medial Gastrocnemius ◽

Lower Extremity Muscle ◽

Prolonged Duration ◽

The Mean ◽

The Impact

Background: Occupational footwear and a prolonged duration of walking have been previously reported to play a role in maintaining postural stability. The purpose of this paper was to analyze the impact of three types of occupational footwear: the steel-toed work boot (ST), the tactical work boot (TB), and the low-top work shoe (LT) on previously unreported lower extremity muscle activity during postural stability tasks. Methods: Electromyography (EMG) muscle activity was measured from four lower extremity muscles (vastus medialis (VM), medial hamstrings (MH), tibialis anterior (TA), and medial gastrocnemius (MG) during maximal voluntary isometric contractions (MVIC) and during a sensory organization test (SOT) every 30 min over a 4 h simulated workload while wearing ST, TB, and LT footwear. The mean MVIC and the mean and percentage MVIC during each SOT condition from each muscle was analyzed individually using a repeated measures ANOVA at an alpha level of 0.05. Results: Significant differences (p < 0.05) were found for maximal exertions, but this was limited to only the time main effect. No significant differences existed for EMG measures during the SOT. Conclusion: The findings suggest that occupational footwear type does not influence lower extremity muscle activity during both MVIC and SOT. Significantly lower muscle activity during maximal exertions over the course of the 4 h workload was evident, which can be attributed to localized muscular fatigue, but this was not sufficient to impact muscle activity during postural stability tasks.

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The Ability of Gymnastics Motoric Perceptual Based on Local Culture for Early Childhood in Aceh Province

Budapest International Research and Critics in Linguistics and Education (BirLE) Journal ◽

10.33258/birle.v3i2.907 ◽

2020 ◽

Vol 3 (2) ◽

pp. 749-762

Author(s):

Muhammad Riski Kurniawan ◽

Syamsulrizal Syamsulrizal ◽

Razali Razali ◽

Israwati Israwati

Keyword(s):

Early Childhood ◽

The Body ◽

Local Culture ◽

Homogeneity Test ◽

Tennis Ball ◽

Eyes Closed ◽

Aceh Province ◽

Eyes Open ◽

Perceptual Ability ◽

The Impact

Local culture-based gymnastics is a combination of Seudati dance with Saman dances movements as well as cheerful healthy exercises that are already in kindergarten. The purpose of this study was to determine the impact of the implementation of local culture-based exercise on the motorized perceptual ability of early childhood in Banda Aceh Kindergarten. This study uses a quantitative approach to the type of experimental research. Population and a sample of 30 students were selected by purposive sampling. Data collection techniques of motoric perceptual ability using tests: (1) Standing on the beam while touching the limbs as instructed by the teacher with eyes open, (2 ) Standing on the beam while touching the body as instructed by the teacher with eyes closed, (3) Jumping and landing in a line with two feet pressed together as instructed by the teacher with eyes open, (4) Jumping and landing in a line with two feet pressed together as instructed by the teacher with eyes closed , (5) Walking in balance, (6) Throwing a tennis ball into a basket with a distance of 2 meters. Before the data is analyzed, the research data is tested for the analysis requirements, namely the normality and homogeneity test. Then the data is analyzed using the t-test. Based on the results of data analysis obtained t count (18.455)> t table (2.045), thus it can be concluded that there is a significant influence between local culture-based exercise on the motoric perceptual ability of early childhood in Aceh kindergarten.

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Does Dual Motor Tasks Provokes Posture Adaptations in Healthy Young Adults? A Cross-sectional Study

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/49048.15374 ◽

2021 ◽

Author(s):

Carley Bowman ◽

Aleena Jose ◽

Martin G Rosario

Keyword(s):

Young Adults ◽

Postural Stability ◽

Cross Sectional Study ◽

P Value ◽

Motor Tasks ◽

Anova Analysis ◽

Dual Tasks ◽

Cross Sectional ◽

Eyes Closed ◽

Eyes Open

Introduction: Most studies on postural deviations during single and dual tasks have been extensively studied in neuromuscular and older adult populations. Nevertheless, further research is warranted to identify whether such tasks can impose postural adaptations in young, healthy adults without sensory impairments. Aim: To assess postural stability modifications in young adults during single tasks and dual motor tasks (holding a cup filled with water) while concomitantly challenging the sensory systems. Materials and Methods: This was the cross-sectional study on 82 young adults (18-45 years old) from Texas Woman’s University (TWU) Health Science Center in Dallas, Texas, and surrounding areas. Standing postural control was measured by collecting total sway, direction of sway and velocity in the Anterior-Posterior (AP) and Medial-Lateral (ML) directions during different balance tasks. For single and dual tasks, the tests were performed with a bipedal stance on foam involving challenging the sensory input via Eyes Open (EO), Eyes Closed (EC), and head movements with eyes open (EO HUD) and closed (EC HUD). The dual motor tasks were similar to the single tasks with the addition of holding a cup full of water to split attention. Data were placed into the Statistical Package for Social Sciences (SPSS) Data Analysis 25.0 system and were analysed for repeated measures Analysis of Variance (ANOVA) analysis. Results: Eighty-two healthy young adults participated in this study (mean age of 24.6±2.7 years, 13 males and 69 females). An ANOVA analysis revealed that postural stability was considerably altered during motor tasks. Sway in the Antero-Posterior (AP) direction, and velocity of sway increased as the complexity of the tasks intensified. A substantial difference in total sway during single tasks when eyes were closed compared to eyes open (p-value <0.01) was noted. There was a significant difference in total sway (AP and ML) during eyes open (EOM) to eyes closed (ECM) and during eyes open with head moving up and down (EOM HUD) (p-value 0.001). There were significant differences in mean AP velocity during EO (0.11±0.12) compared to EC HUD (0.19±0.15), and when comparing EOM (0.07±0.04) to ECM HUD (0.13±0.08) (p=0.01) Conclusion: This study identified postural changes when comparing single and dual tasks in healthy young adults, and the outcomes of this study showed definite distinctions in postural responses during single and dual motor tasks.

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Postural Stability in Athletes: The Role of Age, Sex, Performance Level, and Athlete Shoe Features

Sports ◽

10.3390/sports8060089 ◽

2020 ◽

Vol 8 (6) ◽

pp. 89

Author(s):

Albina Andreeva ◽

Andrey Melnikov ◽

Dmitry Skvortsov ◽

Kadriya Akhmerova ◽

Alexander Vavaev ◽

...

Keyword(s):

Postural Stability ◽

Female Athletes ◽

Center Of Pressure ◽

Performance Level ◽

Eyes Closed ◽

Different Types ◽

Eyes Open ◽

Athletic Shoes ◽

Posture Stability

The effects of different factors—such as age, sex, performance level, and athletic shoe features—on postural balance in athletes remain unclear. The main objective of our study is to identify the features of postural stability in athletes of different age, sex, performance level, and using different types of athletic shoes. This study assessed postural stability in athletes (n = 936, 6–47 years) in a normal bipedal stance with eyes open (EO) and eyes closed (EC). Postural stability was evaluated based on the center of pressure (COP), sway area (AS), and velocity (VCP) while standing on a stabiloplatform. Children (6–12 years) and teen athletes (13–17 years) showed reduced AS-EO (p < 0.01) and VCP-EO (p < 0.01) compared to control (n = 225, 7–30 years). In male and female athletes aged 18+, only VCP-EC was lower versus control. In females (13–17 and 18+), VCP-EO and EC were lower than in males (p < 0.05). Only in the Shooting group, the athletes’ performance levels had an effect on VCP-EO (p = 0.020). Long use of rigid athletic shoes with stiff ankle support was associated with reduced posture stability. Postural stability in athletes was mostly influenced by the athlete‘s age, and, to a lesser extent, by their sex, performance level, and athlete shoe features.

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Postural Stability in Obese Preoperative Bariatric Patients Using Static and Dynamic Evaluation

Obesity Facts ◽

10.1159/000509163 ◽

2020 ◽

Vol 13 (5) ◽

pp. 499-513

Author(s):

Gabriel M. Pagnotti ◽

Amna Haider ◽

Ariel Yang ◽

Kathryn E. Cottell ◽

Catherine M. Tuppo ◽

...

Keyword(s):

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Postural Instability ◽

Patient Specific ◽

Morbidly Obese ◽

Tissue Quality ◽

Eyes Closed ◽

Obese Subjects ◽

The Impact

Introduction: Globally, 300 million adults have clinical obesity. Heightened adiposity and inadequate musculature secondary to obesity alter bipedal stance and gait, diminish musculoskeletal tissue quality, and compromise neuromuscular feedback; these physiological changes alter stability and increase injury risk from falls. Studies in the field focus on obese patients across a broad range of body mass indices (BMI >30 kg/m2) but without isolating the most morbidly obese subset (BMI ≥40 kg/m2). We investigated the impact of obesity in perturbing postural stability in morbidly obese subjects elected for bariatric intervention, harboring a higher-spectrum BMI. Subjects and Methods: Traditional force plate measurements and stabilograms are gold standards employed when measuring center of pressure (COP) and postural sway. To quantify the extent of postural instability in subjects with obesity before bariatric surgery, we assessed 17 obese subjects with an average BMI of 40 kg/m2 in contrast to 13 nonobese subjects with an average BMI of 30 kg/m2. COP and postural sway were measured from static and dynamic tasks. Involuntary movements were measured when patients performed static stances, with eyes either opened or closed. Two additional voluntary movements were measured when subjects performed dynamic, upper torso tasks with eyes opened. Results: Mean body weight was 85% (p < 0.001) greater in obese than nonobese subjects. Following static balance assessments, we observed greater sway displacement in the anteroposterior (AP) direction in obese subjects with eyes open (87%, p < 0.002) and eyes closed (76%, p = 0.04) versus nonobese subjects. Obese subjects also exhibited a higher COP velocity in static tests when subjects’ eyes were open (47%, p = 0.04). Dynamic tests demonstrated no differences between groups in sway displacement in either direction; however, COP velocity in the mediolateral (ML) direction was reduced (31%, p < 0.02) in obese subjects while voluntarily swaying in the AP direction, but increased in the same cohort when swaying in the ML direction (40%, p < 0.04). Discussion and Conclusion: Importantly, these data highlight obesity’s contribution towards increased postural instability. Obese subjects exhibited greater COP displacement at higher AP velocities versus nonobese subjects, suggesting that clinically obese individuals show greater instability than nonobese subjects. Identifying factors contributory to instability could encourage patient-specific physical therapies and presurgical measures to mitigate instability and monitor postsurgical balance improvements.

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Impact of Global Mean Normalization on Regional Glucose Metabolism in the Human Brain

Neural Plasticity ◽

10.1155/2018/6120925 ◽

2018 ◽

Vol 2018 ◽

pp. 1-16 ◽

Cited By ~ 4

Author(s):

Kristian N. Mortensen ◽

Albert Gjedde ◽

Garth J. Thompson ◽

Peter Herman ◽

Maxime J. Parent ◽

...

Keyword(s):

Glucose Metabolism ◽

Human Brain ◽

Disease Biomarkers ◽

Eyes Closed ◽

Positron Emission ◽

Congenitally Blind ◽

Eyes Open ◽

Health And Disease ◽

The Impact ◽

Global Mean

Because the human brain consumes a disproportionate fraction of the resting body’s energy, positron emission tomography (PET) measurements of absolute glucose metabolism (CMRglc) can serve as disease biomarkers. Global mean normalization (GMN) of PET data reveals disease-based differences from healthy individuals as fractional changes across regions relative to a global mean. To assess the impact of GMN applied to metabolic data, we compared CMRglc with and without GMN in healthy awake volunteers with eyes closed (i.e., control) against specific physiological/clinical states, including healthy/awake with eyes open, healthy/awake but congenitally blind, healthy/sedated with anesthetics, and patients with disorders of consciousness. Without GMN, global CMRglc alterations compared to control were detected in all conditions except in congenitally blind where regional CMRglc variations were detected in the visual cortex. However, GMN introduced regional and bidirectional CMRglc changes at smaller fractions of the quantitative delocalized changes. While global information was lost with GMN, the quantitative approach (i.e., a validated method for quantitative baseline metabolic activity without GMN) not only preserved global CMRglc alterations induced by opening eyes, sedation, and varying consciousness but also detected regional CMRglc variations in the congenitally blind. These results caution the use of GMN upon PET-measured CMRglc data in health and disease.

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