scholarly journals Acrophobia and visual height intolerance: advances in epidemiology and mechanisms

2020 ◽  
Vol 267 (S1) ◽  
pp. 231-240
Author(s):  
Doreen Huppert ◽  
Max Wuehr ◽  
Thomas Brandt
Keyword(s):  
Motor Behavior ◽  
Behavioral Therapy ◽  
Critical Factor ◽  
Epidemiological Studies ◽  
Visual Exploration ◽  
Whole Body ◽  
Bilateral Vestibulopathy ◽  
Double Support ◽  
Roman Antiquity ◽  
Visual Height Intolerance

AbstractHistorical descriptions of fear at heights date back to Chinese and Roman antiquity. Current definitions distinguish between three different states of responses to height exposure: a physiological height imbalance that results from an impaired visual control of balance, a more or less distressing visual height intolerance, and acrophobia at the severest end of the spectrum. Epidemiological studies revealed a lifetime prevalence of visual height intolerance including acrophobia in 28% of adults (32% in women; 25% in men) and 34% among prepubertal children aged 8–10 years without gender preponderance. Visual height intolerance first occurring in adulthood usually persists throughout life, whereas an early manifestation in childhood usually shows a benign course with spontaneous relief within years. A high comorbidity was found with psychiatric disorders (e.g. anxiety and depressive syndromes) and other vertigo syndromes (e.g. vestibular migraine, Menière’s disease), but not with bilateral vestibulopathy. Neurophysiological analyses of stance, gait, and eye movements revealed an anxious control of postural stability, which entails a co-contraction of anti-gravity muscles that causes a general stiffening of the whole body including the oculomotor apparatus. Visual exploration is preferably reduced to fixation of the horizon. Gait alterations are characterized by a cautious slow walking mode with reduced stride length and increased double support phases. Anxiety is the critical factor in visual height intolerance and acrophobia leading to a motor behavior that resembles an atavistic primitive reflex of feigning death. The magnitude of anxiety and neurophysiological parameters of musculoskeletal stiffening increase with increasing height. They saturate, however, at about 20 m of absolute height above ground for postural symptoms and about 40 m for anxiety (70 m in acrophobic participants). With respect to management, a differentiation should be made between behavioral recommendations for prevention and therapy of the condition. Recommendations for coping strategies target behavioral advices on visual exploration, control of posture and locomotion as well as the role of cognition. Treatment of severely afflicted persons with distressing avoidance behavior mainly relies on behavioral therapy.

Effect of Heel to Toe Walking on Time Optimal Walking of a Biped During Single Support Phase

2014 ◽  
Author(s):  
Tara Farizeh ◽  
Mohammad Jafar Sadigh
Keyword(s):  
Whole Body ◽  
Maximum Speed ◽  
Flat Foot ◽  
Double Support ◽  
Time Optimal ◽  
Foot Model ◽  
Two Phases ◽  
Single Support Phase ◽  
Toe Walking ◽  
Support Phase

Dynamic modeling of a biped has gained lots of attention during past few decades. While stability and energy consumption were among the first issues which were considered by researchers, nowadays achieving maximum speed and improving pattern of motion to reach that speed are the important targets in this field. Walking model of bipeds usually includes two phases, single support phase (SSP), in which only the stance foot is in contact with the ground while the opposite leg is swinging; and double support phase (DSP) in which the swing leg is in contact with the ground in addition to the rear foot. It is common in the simplified model of walking to assume the stance leg foot, flat during the entire SSP; but one may know that for human walking, there is also a sub-phase during SSP in which the heel of stance foot leaves the ground while the whole body is supported by toe link. Actually in this sub phase the stance leg foot rotates around the toe joint. This paper is trying to study the effect of toe-link and heel to toe walking model on dynamic and specially speed of walking compare to flat foot model.

scholarly journals Increased cardiovascular risk markers in obesity are associated with body adiposity: Role of leptin

2006 ◽  
Vol 95 (06) ◽  
pp. 991-996 ◽  
Author(s):  
Javier Gómez-Ambrosi ◽  
Javier Salvador ◽  
Camilo Silva ◽  
Carlos Pastor ◽  
Fernando Rotellar ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Epidemiological Studies ◽  
Cross Sectional Study ◽  
Whole Body ◽  
Cross Sectional ◽  
Blood Concentrations ◽  
Air Displacement Plethysmography ◽  
Reactive Protein ◽  
Obese Subjects ◽  
Von Willebrand

SummaryEpidemiological studies have shown that obesity is associated with increased blood concentrations of proinflammatory factors and markers of endothelial dysfunction such as fibrinogen, C-reactive protein (CRP), and von Willebrand factor (vWF). We analyzed the association of these markers with percentage of body fat (BF), and the influence of leptin in a cross-sectional study of 1,089 subjects (366 men) aged 44 (34–53) [median (interquartile range)] years, who were classified as obese or non-obese according to BF estimated by whole-body air displacement plethysmography. Obesity was defined as BF ≥ 25% in men and ≥ 35% in women. Compared with non-obese subjects (mean ± SD), obese patients had higher concentrations of fibrinogen (312± 78 vs. 342 ± 81 mg/dl, P < 0.001), CRP (0.41 ± 0.75 vs. 0.75± 1. 04 mg/l, P = 0.014), vWF (107 ± 29 vs. 123 ± 55%, P < 0.001), and leptin (10.4 ± 6.5 vs. 37.5 ± 26. 1 ng/ml, P < 0.0001). A positive correlation was observed between BF and fibrinogen (r = 0.266; P < 0.0001), logCRP (r = 0.409; P < 0.0001), and vWF (r = 206; P < 0.0001). Leptin was correlated with fibrinogen (r = 0.219, P < 0.0001), logCRP (r = 0.339, P < 0.0001), and vWF (r = 0.124, P = 0.002), but the statistical significance was lost after including BF in adjusted-correlation and multivariate analysis, suggesting that they are not regulated by leptin per se. In conclusion, the obesity-associated increase in the circulating concentrations of fibrinogen, CRP, and vWF is highly associated to BF and apparently not determined by leptin.

Sensorimotor and Perceptual Function of Muscle Proprioception in Microgravity

1993 ◽  
Vol 3 (3) ◽  
pp. 259-273
Author(s):  
J.P. Roll ◽  
K. Popov ◽  
V. Gurfinkel ◽  
M. Lipshits ◽  
C. André-Deshays ◽  
...  
Keyword(s):  
Motor Behavior ◽  
Tibialis Anterior Muscle ◽  
Sensory Function ◽  
Whole Body ◽  
Proprioceptive Information ◽  
Muscle Vibration ◽  
Flexor Muscle ◽  
Experimental Conditions ◽  
Postural Responses ◽  
Third Dimension

Adaptive properties of the human proprioceptive systems were studied during the French-Soviet orbital flight (Aragatz mission, December 1988). The present space experiment investigated the hypothesis that the modifications of both biomechanical and physiological conditions occurring under microgravity involve considerable reorganization of body perception and postural control. The proprioceptive information originating in muscles is known to contribute, together with visual, vestibular, and sole cutaneous information to postural regulation. Moreover, by specifically activating the proprioceptive channel, muscle vibration is able to elicit both illusory movement sensations and postural responses. This experimental tool was used in microgravity in order to test various aspects of muscle sensory function. Ankle flexor and extensor vibration was applied under different experimental conditions. Quantitative analysis of motor responses was carried out on leg muscle EMG, goniometric, and kinesigraphic recordings. Joystick recordings and astronauts’ comments were used to describe the kinaesthetic sensations. The main results were as follows: 1) Under microgravity, the sensitivity of muscle receptors remains unchanged. 2) During the flight, the tonic vibration reflexes (TVR) increased significantly in flexor muscles, which exhibited a sustained tonic activity. 3) The whole-body postural responses normally induced by ankle flexor muscle vibration were suppressed, whereas they remained unchanged or were only reduced when vibrations were applied to the ankle extensor muscles. In all cases, the postural response velocity decreased. 4) A disfacilitation of the vibration-induced postural illusions was observed to occur during long-term exposure to microgravity. These illusions became atypical however. For example: body lift illusion could be induced by tibialis anterior muscle vibration, whereas it was never induced in the controls. The characteristics of the illusory body movements described under normal gravity can be restored by artificially increasing the axial foot support forces during the flight. In conclusion, these data suggest that a functional reorganization of the proprioceptive information processing occurs in microgravity, affecting both perceptual and motor aspects of behavior. It is possible that these proprioceptive adaptations may be partly attributable to the new whole-body propulsive foot functions imposed by exposure to weightlessness and to the adaptation of motor behavior to the third dimension of space.

scholarly journals The Fetal Origins of the Metabolic Syndrome: Can We Intervene?

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Noelle Ma ◽  
Daniel B. Hardy
Keyword(s):  
Metabolic Syndrome ◽  
Molecular Mechanisms ◽  
Dietary Intervention ◽  
Critical Factor ◽  
Epidemiological Studies ◽  
Fetal Life ◽  
Fetal Origins ◽  
The Metabolic Syndrome ◽  
Neonatal Life

Epidemiological studies have suggested that metabolic programming begins during fetal life and adverse eventsin uteroare a critical factor in the etiology of chronic diseases and overall health. While the underlying molecular mechanisms linking impaired fetal development to these adult diseases are being elucidated, little is known about how we can intervene early in life to diminish the incidence and severity of these long-term diseases. This paper highlights the latest clinical and pharmaceutical studies addressing how dietary intervention in fetal and neonatal life may be able to prevent aspects of the metabolic syndrome associated with IUGR pregnancies.

scholarly journals Molecular Probes for Evaluation of Oxidative Stress by In Vivo EPR Spectroscopy and Imaging: State-of-the-Art and Limitations

2019 ◽  
Vol 5 (1) ◽  
pp. 13 ◽  
Author(s):  
Nikola Babić ◽  
Fabienne Peyrot
Keyword(s):  
Oxidative Stress ◽  
Ex Vivo ◽  
Critical Factor ◽  
Molecular Probes ◽  
Antioxidant Defenses ◽  
Whole Body ◽  
Paramagnetic Resonance ◽  
The Status ◽  
Living Tissues

Oxidative stress, defined as a misbalance between the production of reactive oxygen species and the antioxidant defenses of the cell, appears as a critical factor either in the onset or in the etiology of many pathological conditions. Several methods of detection exist. However, they usually rely on ex vivo evaluation or reports on the status of living tissues only up to a few millimeters in depth, while a whole-body, real-time, non-invasive monitoring technique is required for early diagnosis or as an aid to therapy (to monitor the action of a drug). Methods based on electron paramagnetic resonance (EPR), in association with molecular probes based on aminoxyl radicals (nitroxides) or hydroxylamines especially, have emerged as very promising to meet these standards. The principles involve monitoring the rate of decrease or increase of the EPR signal in vivo after injection of the nitroxide or the hydroxylamine probe, respectively, in a pathological versus a control situation. There have been many successful applications in various rodent models. However, current limitations lie in both the field of the technical development of the spectrometers and the molecular probes. The scope of this review will mainly focus on the latter.

Effects of chronic coffee consumption on glucose kinetics in the conscious rat

2007 ◽  
Vol 85 (8) ◽  
pp. 823-830 ◽  
Author(s):  
J. Shearer ◽  
E.A. Sellars ◽  
A. Farah ◽  
T.E. Graham ◽  
D.H. Wasserman
Keyword(s):  
Coffee Consumption ◽  
Epidemiological Studies ◽  
Whole Body ◽  
Metabolic Clearance ◽  
Sprague Dawley ◽  
Glucose Kinetics ◽  
Conscious Rat ◽  
Beneficial Effects ◽  
Decaffeinated Coffee

Epidemiological studies indicate that regular coffee consumption reduces the risk of developing type 2 diabetes. Despite these findings, the biological mechanisms by which coffee consumption exerts these effects are unknown. The aim of this study was twofold: to develop a rat model that would further delineate the effects of regular coffee consumption on glucose kinetics, and to determine whether coffee, with or without caffeine, alters the actions of insulin on glucose kinetics in vivo. Male Sprague–Dawley rats were fed a high-fat diet for 4 weeks in combination with one of the following: (i) drinking water as placebo (PL), (ii) decaffeinated coffee (2 g/100 mL) (DC), or (iii) alkaloid caffeine (20 mg/100 mL) added to decaffeinated coffee (2 g/100 mL) (CAF). Catheters were chronically implanted in a carotid artery and jugular vein for sampling and infusions, respectively. Recovered animals (5 days postoperative) were fasted for 5 h before hyperinsulinemic-euglycemic clamps (2 mU·kg–1·min–1). Glucose was clamped at 6 mmol/L and isotopes (2-deoxy-[14C]glucose and [3-3H]glucose) were administered to obtain indices of whole-body and tissue-specific glucose kinetics. Glucose infusion rates and measures of whole-body metabolic clearance were greater in DC than in PL or CAF, indicating increased whole-body insulin sensitivity. As the only difference between DC and CAF was the addition of alkaloid caffeine, it can be concluded that caffeine antagonizes the beneficial effects of DC. Given these findings, decaffeinated coffee may represent a nutritional means of combating insulin resistance.

scholarly journals PENGARUH TERAPI PERILAKU KOQNITIF TERHADAP GAMBARAN DIRI: SISTEMATIKA REVIEW

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Resmi Pangaribuan ◽  
Putri Nanda Sari
Keyword(s):  
Body Image ◽  
Cognitive Behavioral Therapy ◽  
Irrational Beliefs ◽  
Behavioral Therapy ◽  
Original Data ◽  
Cognitive Behavioral ◽  
Body Image Disturbance ◽  
Whole Body ◽  
Inclusion Criteria ◽  
Body Area

Body image is a crucial factor in the formation of individual identity. Increasing body image on an individual requires an intervention which can change thoughts, feelings and attitudes affecting the behavior related to the whole body and its function. This systematic review evaluates the existed evidence to identify the effect of Cognitive Behavioral Therapy (CBT) on body image. The literature review is conducted by selecting the corresponding articles which are published between 2011 and 2017. Various databases used are CINAHL, EBSCO, Proquest, Pubmed, Science Direct, and Semantic Scholar. The inclusion criteria are the articles publishing original data, being fully written in English, researching human as an object and exploring the cognitive behavioral therapy and body image. There are eight articles that showed the effect of cognitive behavioral therapy on body image including reducing body image concern, reducing bad stigma towards body image and irrational beliefs on body changing, increasing body area satisfaction, improving appearance evaluation and improving a positive body image. The application of cognitive behavioral therapy is essential and effective in improving body image. This study recommends health professionals, especially nurses, to apply cognitive behavioral therapy in patients with various diseases involving body image disturbance.

scholarly journals Identifying differences in gait adaptability across various speeds using movement synergy analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244582
Author(s):  
David Ó’Reilly ◽  
Peter Federolf
Keyword(s):  
Principal Component ◽  
Neuromuscular Control ◽  
Whole Body ◽  
Supporting Evidence ◽  
Normal Walking ◽  
Optimal Model ◽  
Double Support ◽  
Leg Dominance ◽  
Perturbed Walking

Introduction The aim of this study was to identify movement synergies during normal-walking that can differentiate healthy adults in terms of gait adaptability at various speeds. To this end, the association between movement synergies and lower-limb coordination variability or Deviation Phase (DP) was investigated. This study also investigated the moderating effect of movement synergies on the relationship between DP and the smoothness of arm-swing motion (NJI). Method A principal component analysis of whole-body marker trajectories from normal-walking treadmill trials at 0.8m/s, 1.2m/s and 1.6m/s was undertaken. Both DP and NJI were derived from approx. 8 minutes of perturbed-walking treadmill trials. Principal movement components, PMk, were derived and the RMS of the 2nd-order differentiation of these PMk (PAkRMS) were included as independent variables representing the magnitude of neuromuscular control in each PMk. Each PAkRMS were input into maximal linear mixed-effects models against DP and (DP x NJI) respectively. A stepwise elimination of terms and comparison of models using Anova identified optimal models for both aims. Results The principal movement related to the push-off mechanism of gait (PA4RMS) was identified as an optimal model and demonstrated a significant negative effect on DP however this effect may differ considerably across walking-speeds. An optimal model for describing the variance in (DP x NJI) included a fixed-effect of PA6RMS representing Right—Left side weight transfer was identified. Interpretation The hypotheses that individuals who exhibited greater control on specific kinematic synergies would exhibit variations during perturbed walking was substantiated. Supporting evidence for the role of movement synergies during the double-support phase of gait in proactively correcting balance was presented as well as the potential for this approach in targeted rehabilitation. The potential influence of leg dominance on gait adaptability was also discussed. Future studies should investigate further the role of walking-speed and leg dominance on movement synergies and look to generalize these findings to patient populations.

scholarly journals A whole body characterization of individual strategies, gender differences, and common styles in overarm throwing

2019 ◽  
Vol 122 (6) ◽  
pp. 2486-2503 ◽  
Author(s):  
Antonella Maselli ◽  
Aishwar Dhawan ◽  
Marta Russo ◽  
Benedetta Cesqui ◽  
Francesco Lacquaniti ◽  
...  
Keyword(s):  
Gender Differences ◽  
Motor Control ◽  
Skill Acquisition ◽  
Motor Development ◽  
Motor Behavior ◽  
Developmental Trajectory ◽  
Gender Effects ◽  
Whole Body ◽  
Overarm Throwing ◽  
And Gender

Overarm throwing is a fundamental human skill. Since paleolithic hunter-gatherer societies, the ability of throwing played a key role in brain and body co-evolution. For decades, throwing skill acquisition has been the subject of developmental and gender studies. However, due to its complex multijoint nature, whole body throwing has found little space in quantitative studies of motor behavior. In this study we examined how overarm throwing varies within and between individuals in a sample of untrained adults. To quantitatively compare whole body kinematics across throwing actions, we introduced a new combination of spatiotemporal principal component, linear discrimination, and clustering analyses. We found that the identity and gender of a thrower can be robustly inferred by the kinematics of a single throw, reflecting the characteristic features in individual throwing strategies and providing a quantitative ground for the well-known differences between males and females in throwing behavior. We also identified four main classes of throwing strategies, stable within individuals and resembling the main stages of throwing proficiency acquisition during motor development. These results support earlier proposals linking interindividual and gender differences in throwing, with skill acquisition interrupted at different stages of the typical developmental trajectory of throwing motor behavior. NEW & NOTEWORTHY Unconstrained throwing, because of its complexity, received little attention in quantitative motor control studies. By introducing a new approach to analyze whole body kinematics, we quantitatively characterized gender effects, interindividual differences, and common patterns in nontrained throwers. The four throwing styles identified across individuals resemble different stages in the acquisition of throwing skills during development. These results advance our understanding of complex motor skills, bridging the gap between motor control, motor development, and sport science.

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