Descending pain modulation and its interaction with peripheral sensitization following sustained isometric muscle contraction in fibromyalgia

DEFF Research Database (Denmark)

Ge, H-Y; Nie, Hongling; Graven-Nielsen, Thomas

2012-01-01

OBJECTIVE: Sustained isometric muscle contraction (fatiguing contraction) recruits segmental and/or extrasegmental descending inhibition in healthy subjects but not in fibromyalgia (FM). We hypothesized that fatiguing contraction may shift descending pain modulation from inhibition towards...

Sustained inhibition of rat myometrial gap junctions and contractions by lindane

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Grindatti Carmen M

2003-10-01

Full Text Available Abstract Background Gap junctions increase in size and abundance coincident with parturition, forming an intercellular communication network that permits the uterus to develop the forceful, coordinated contractions necessary for delivery of the fetus. Lindane, a pesticide used in the human and veterinary treatment of scabies and lice as well as in agricultural applications, inhibits uterine contractions in vitro, inhibits myometrial gap junctions, and has been associated with prolonged gestation length in rats. The aim of the present study was to investigate whether brief exposures to lindane would elicit sustained inhibition of rat uterine contractile activity and myometrial gap junction intercellular communication. Methods To examine effects on uterine contraction, longitudinal uterine strips isolated from late gestation (day 20 rats were exposed to lindane in muscle baths and monitored for changes in spontaneous phasic contractions during and after exposure to lindane. Lucifer yellow dye transfer between myometrial cells in culture was used to monitor gap junction intercellular communication. Results During a 1-h exposure, 10 micro M and 100 micro M lindane decreased peak force and frequency of uterine contraction but 1 micro M lindane did not. After removal of the exposure buffer, contraction force remained significantly depressed in uterine strips exposed to 100 micro M lindane, returning to less than 50% basal levels 5 h after cessation of lindane exposure. In cultured myometrial myocytes, significant sustained inhibition of Lucifer yellow dye transfer was observed 24 h after lindane exposures as brief as 10 min and as low as 0.1 micro M lindane. Conclusion Brief in vitro exposures to lindane have long-term effects on myometrial functions that are necessary for parturition, inhibiting spontaneous phasic contractions in late gestation rat uterus and gap junction intercellular communication in myometrial cell cultures.

A radiological study on the effect of postural changes after far meal on contraction of the gallbladder

International Nuclear Information System (INIS)

Choi, Il Bong; Park, Seog Hee; Yim, Jeong Ik; Kim, Jong Woo; Bahk, Yong Whee

1982-01-01

Oral cholecystography is one of the most reliable and widely used x-ray examination which enables us to observed not only morphological features of the gallbladder (GB) but also functioning state. It was disclosed that functional evaluation of the GB is mandatory to recognize such kinetic disorders of the viscus as acalculous cholecystitis or dyskinesia. For the purpose of functional evaluation, fat meal has been used traditionally. Recently, cholecystokinin (CCK) and ceruletide were introduced into clinical diagnosis of the GB, the usefulness of which we have confirmed. In the present study we have made an attempt at improving cholecystagogic effect of conventional fat meals(FM) such as whole milk and egg yolk by changing the posture of the examined from sitting up to right decubitus position after the ingestion of fat meal. The hypothesis involved in this study is that the presence of quantitatively more fat meal in the duodenum per unit time may result in more effective cholecystagogic action and such a setting would be created by enhancement of pyloric passage of fat meal by decubitus posturing. Clinical materials consisted of 280 normal oral GB series (136 males and 144 females) and they were divided into 4 equally numbered groups of milk sitting and milk decubitus and egg sitting and egg decubitus. Upon confirming satisfactory opacification of the GB 11 hours after the ingestion of 3 g of sodium ipodate or iopanoic acid either 2 pieces of medium sized hen's egg yolk were given. The xaminess were than allowed either sitting up comfortably on a bench or lying down on the right flank on a couch. After the ingestion of fat mean, x-ray was taken at the end of 30 minutes in all but the milk decubitus group in which x-rays were taken serially at the end of 5, 15, 30 and 60 minutes. The frontal area of each opacified GB was measured by using a planimeter and the contraction rate before and after fat meal stimulation was calculated by the following equation and

A radiological study on the effect of postural changes after far meal on contraction of the gallbladder

Energy Technology Data Exchange (ETDEWEB)

Choi, Il Bong; Park, Seog Hee; Yim, Jeong Ik; Kim, Jong Woo; Bahk, Yong Whee [Catholic Medical College, Seoul (Korea, Republic of)

1982-06-15

Oral cholecystography is one of the most reliable and widely used x-ray examination which enables us to observed not only morphological features of the gallbladder (GB) but also functioning state. It was disclosed that functional evaluation of the GB is mandatory to recognize such kinetic disorders of the viscus as acalculous cholecystitis or dyskinesia. For the purpose of functional evaluation, fat meal has been used traditionally. Recently, cholecystokinin (CCK) and ceruletide were introduced into clinical diagnosis of the GB, the usefulness of which we have confirmed. In the present study we have made an attempt at improving cholecystagogic effect of conventional fat meals(FM) such as whole milk and egg yolk by changing the posture of the examined from sitting up to right decubitus position after the ingestion of fat meal. The hypothesis involved in this study is that the presence of quantitatively more fat meal in the duodenum per unit time may result in more effective cholecystagogic action and such a setting would be created by enhancement of pyloric passage of fat meal by decubitus posturing. Clinical materials consisted of 280 normal oral GB series (136 males and 144 females) and they were divided into 4 equally numbered groups of milk sitting and milk decubitus and egg sitting and egg decubitus. Upon confirming satisfactory opacification of the GB 11 hours after the ingestion of 3 g of sodium ipodate or iopanoic acid either 2 pieces of medium sized hen's egg yolk were given. The xaminess were than allowed either sitting up comfortably on a bench or lying down on the right flank on a couch. After the ingestion of fat mean, x-ray was taken at the end of 30 minutes in all but the milk decubitus group in which x-rays were taken serially at the end of 5, 15, 30 and 60 minutes. The frontal area of each opacified GB was measured by using a planimeter and the contraction rate before and after fat meal stimulation was calculated by the following equation and

Motor unit recruitment and bursts of activity in the surface electromyogram during a sustained contraction.

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Riley, Zachary A; Terry, Mary E; Mendez-Villanueva, Alberto; Litsey, Jane C; Enoka, Roger M

2008-06-01

Bursts of activity in the surface electromyogram (EMG) during a sustained contraction have been interpreted as corresponding to the transient recruitment of motor units, but this association has never been confirmed. The current study compared the timing of trains of action potentials discharged by single motor units during a sustained contraction with the bursts of activity detected in the surface EMG signal. The 20 motor units from 6 subjects [recruitment threshold, 35.3 +/- 11.3% maximal voluntary contraction (MVC) force] that were detected with fine wire electrodes discharged 2-9 trains of action potentials (7.2 +/- 5.6 s in duration) when recruited during a contraction that was sustained at a force below its recruitment threshold (target force, 25.4 +/- 10.6% MVC force). High-pass filtering the bipolar surface EMG signal improved its correlation with the single motor unit signal. An algorithm applied to the surface EMG was able to detect 75% of the trains of motor unit action potentials. The results indicate that bursts of activity in the surface EMG during a constant-force contraction correspond to the transient recruitment of higher-threshold motor units in healthy individuals, and these results could assist in the diagnosis and design of treatment in individuals who demonstrate deficits in motor unit activation.

Anatomy and histochemistry of spread-wing posture in birds. 2. Gliding flight in the California gull, Larus californicus: a paradox of fast fibers and posture.

Science.gov (United States)

Meyers, R A; Mathias, E

1997-09-01

Gliding flight is a postural activity which requires the wings to be held in a horizontal position to support the weight of the body. Postural behaviors typically utilize isometric contractions in which no change in length takes place. Due to longer actin-myosin interactions, slow contracting muscle fibers represent an economical means for this type of contraction. In specialized soaring birds, such as vultures and pelicans, a deep layer of the pectoralis muscle, composed entirely of slow fibers, is believed to perform this function. Muscles involved in gliding posture were examined in California gulls (Larus californicus) and tested for the presence of slow fibers using myosin ATPase histochemistry and antibodies. Surprisingly small numbers of slow fibers were found in the M. extensor metacarpi radialis, M. coracobrachialis cranialis, and M. coracobrachialis caudalis, which function in wrist extension, wing protraction, and body support, respectively. The low number of slow fibers in these muscles and the absence of slow fibers in muscles associated with wing extension and primary body support suggest that gulls do not require slow fibers for their postural behaviors. Gulls also lack the deep belly to the pectoralis found in other gliding birds. Since bird muscle is highly oxidative, we hypothesize that fast muscle fibers may function to maintain wing position during gliding flight in California gulls.

Measuring postural control during mini-squat posture in men with early knee osteoarthritis.

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Petrella, M; Gramani-Say, K; Serrão, P R M S; Lessi, G C; Barela, J A; Carvalho, R P; Mattiello, S M

2017-04-01

Studies have suggested a compromised postural control in individuals with knee osteoarthritis (OA) evidenced by larger and faster displacement of center of pressure (COP). However, quantification of postural control in the mini-squat posture performed by patients with early knee OA and its relation to muscle strength and self-reported symptoms have not been investigated. The main aim of this cross-sectional, observational, controlled study was to determine whether postural control in the mini-squat posture differs between individuals with early knee OA and a control group (CG) and verify the relation among knee extensor torque (KET) and self-reported physical function, stiffness and pain. Twenty four individuals with knee OA grades I and II (OAG) (mean age: 52.35±5.00) and twenty subjects without knee injuries (CG) (mean age: 51.40±8.07) participated in this study. Participants were assessed in postural control through a force plate (Bertec Mod. USA), which provided information about the anterior-posterior (AP) and medial-lateral (ML) COP displacement during the mini-squat, in isometric, concentric and eccentric knee extensor torque (KET) (90°/s) through an isokinetic dynamometer (BiodexMulti-Joint System3, Biodex Medical Incorporation, New York, NY, USA), and in self-reported symptoms through the WOMAC questionnaire. The main outcomes measured were the AP and ML COP amplitude and velocity of displacement; isometric, concentric, and eccentric KET and self-reported physical function, stiffness and pain. No significant differences were found between groups for postural control (p>0.05). Significant lower eccentric KET (p=0.01) and higher scores for the WOMAC subscales of pain (p=postural instability and the need to include quadriceps muscle strengthening, especially by eccentric contractions. The relationship between the self-reported symptoms and a lower and slower COP displacement suggest that the postural control strategy during tasks with a semi-flexed knee

CALF BLOOD-FLOW AND POSTURE - DOPPLER ULTRASOUND MEASUREMENTS DURING AND AFTER EXERCISE

NARCIS (Netherlands)

VANLEEUWEN, BE; BARENDSEN, GJ; LUBBERS, J; DEPATER, L

To investigate the joint effects of body posture and calf muscle pump, the calf blood flow of eight healthy volunteers was measured with pulsed Doppler equipment during and after 3 min of rhythmic exercise on a calf ergometer in the supine, sitting, and standing postures. Muscle contractions

Postural Muscle Dyscoordination in Children With Cerebral Palsy

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Jolanda C. van der Heide

2005-01-01

Full Text Available The present paper gives an overview of the knowledge currently available on muscular dyscoordination underlying postural problems in children with cerebral palsy (CP. Such information is a prerequisite for developing successful therapeutic interventions in children with CP. Until now, three children with CP functioning at GMFCS (Gross Motor Function Classification System level V have been documented. The children totally or partially lacked direction specificity in their postural adjustments and could not sit independently for more than 3 seconds. Some children functioning at GMFCS level IV have intact direction-specific adjustments, whereas others have problems in generating consistently direction-specific adjustments. Children at GMFCS levels I to III have an intact basic level of control but have difficulties in fine-tuning the degree of postural muscle contraction to the task-specific conditions, a dysfunction more prominently present in children with bilateral spastic CP than in children with spastic hemiplegia. The problems in the adaptation of the degree of muscle contraction might be the reason that children with CP, more often than typically developing children, show an excess of antagonistic coactivation during difficult balancing tasks and a preference for cranial-caudal recruitment during reaching. This might imply that both stereotypies might be regarded as functional strategies to compensate for the dysfunctional capacity to modulate subtly postural activity.

Meta-Analysis: Association Between Wrist Posture and Carpal Tunnel Syndrome Among Workers

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Doohee You

2014-03-01

Conclusion: We found evidence that prolonged exposure to non-neutral wrist postures is associated with a twofold increased risk for CTS compared with low hours of exposure to non-neutral wrist postures. Workplace interventions to prevent CTS should incorporate training and engineering interventions that reduce sustained non-neutral wrist postures.

The Potential Risk Factors Relevant to Lateral Epicondylitis by Wrist Coupling Posture.

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Su-Ya Lee

Full Text Available The use of awkward wrist postures and unskilled techniques might induce lateral epicondylitis. This study thus investigated the effects of wrist deviation combined with extension and movement velocity on the dynamic performances of the wrist muscles during the coupling posture via a custom-made bi-planar isokinetic dynamometer. Thirty subjects were recruited to perform the isokinetic testing. We measured the muscle strengths and activities for the wrist extensors and flexors during concentric and eccentric contractions at three movement velocities, 30°s-1, 90°s-1, and 180°s-1, combined with three wrist postures, neutral position (NP, radial deviation (RD, and ulnar deviation (UD. The root mean square (RMS of the electromyographic signal in the extensor digitorum communis (EDC, normalized peak torque of extensors, and ratio of normalized peak torque between wrist extensors and flexors, were all greater in the NP than RD and UD in both contractions. The ratio of RMS between EDC and flexor digitorum superficialis (FDS had a significantly greater value in RD than UD during the concentric contraction. The EDC showed significantly higher activity at the fast velocity in both contractions. Nevertheless, a significantly higher RMS of the electromyographic signal between EDC and FDS and the ratio of strength between wrist extensors and flexors were found at slow velocity in both contractions. The wrist deviation combined with extension and movement velocity of the wrist joint should thus be considered as influential factors which might alter the dynamic performances, and may result in further injury of the elbow joint.

Store-operated calcium entry is required for sustained contraction and Ca2+ oscillations of airway smooth muscle.

Science.gov (United States)

Chen, Jun; Sanderson, Michael J

2017-05-15

Airway hyper-responsiveness in asthma is driven by excessive contraction of airway smooth muscle cells (ASMCs). Agonist-induced Ca 2+ oscillations underlie this contraction of ASMCs and the magnitude of this contraction is proportional to the Ca 2+ oscillation frequency. Sustained contraction and Ca 2+ oscillations require an influx of extracellular Ca 2+ , although the mechanisms and pathways mediating this Ca 2+ influx during agonist-induced ASMC contraction are not well defined. By inhibiting store-operated calcium entry (SOCE) or voltage-gated Ca 2+ channels (VGCCs), we show that SOCE, rather than Ca 2+ influx via VGCCs, provides the major Ca 2+ entry pathway into ASMCs to sustain ASMCs contraction and Ca 2+ oscillations. SOCE may therefore serve as a potential target for new bronchodilators to reduce airway hyper-responsiveness in asthma. Asthma is characterized by airway hyper-responsiveness: the excessive contraction of airway smooth muscle. The extent of this airway contraction is proportional to the frequency of Ca 2+ oscillations within airway smooth muscle cells (ASMCs). Sustained Ca 2+ oscillations require a Ca 2+ influx to replenish Ca 2+ losses across the plasma membrane. Our previous studies implied store-operated calcium entry (SOCE) as the major pathway for this Ca 2+ influx. In the present study, we explore this hypothesis, by examining the effects of SOCE inhibitors (GSK7975A and GSK5498A) as well as L-type voltage-gated Ca 2+ channel inhibitors (nifedipine and nimodipine) on airway contraction and Ca 2+ oscillations and SOCE-mediated Ca 2+ influx in ASMCs within mouse precision-cut lung slices. We found that both GSK7975A and GSK5498A were able to fully relax methacholine-induced airway contraction by abolishing the Ca 2+ oscillations, in a manner similar to that observed in zero extracellular Ca 2+ ([Ca 2+ ] e ). In addition, GSK7975A and GSK5498A inhibited increases in intracellular Ca 2+ ([Ca 2+ ] i ) in ASMCs with depleted Ca 2+ -stores in

Expand your body when you look at yourself: The role of the posture in a mirror exposure task.

Science.gov (United States)

Miragall, Marta; Etchemendy, Ernestina; Cebolla, Ausiàs; Rodríguez, Víctor; Medrano, Carlos; Baños, Rosa María

2018-01-01

Mirror exposure (ME) is one of the main components of the treatment of patients with eating disorders symptomatology and it has shown its effectiveness in improving several outcomes (e.g., body dissatisfaction). However, the study as to what body posture should be adopted to maximize its effectiveness has been neglected. From embodied cognition and emotion theories, the adoption of an expansive (vs. contractive) body posture has been associated with positive changes in cognitive and emotional responses. The objective of this study was to analyze the effect of adopting an expansive (vs. contractive) posture before an ME task on body-related emotions and cognitions, as well as to analyze the possible moderator and mediator variables of these relationships. The sample was composed of 68 women (age: M = 21.74, SD = 3.12) with high scores on body dissatisfaction. Participants were randomly assigned to the expansive or contractive condition, where the openness of the arms/legs and the back position were manipulated. Posture was monitored by an electronic device and participants filled out several self-reported measures. ANCOVAs, moderation, mediation, and moderated mediated analyses were performed. Results showed that women in the expansive condition showed higher positive emotions after the ME. Moreover, exploratory analyses showed that adopting an expansive posture improved positive emotions, leading to improvements in negative emotions, body image satisfaction, and appraisal of the person's own body. Psychological interventions should explore the value of holding an expansive posture before the ME in women with body dissatisfaction.

Towards sustainable infrastructure development through integrated contracts : Experiences with inclusiveness in Dutch infrastructure projects

NARCIS (Netherlands)

Lenferink, Sander; Tillema, Taede; Arts, Jos

Current complex society necessitates finding inclusive arrangements for delivering sustainable road infrastructure integrating design, construction and maintenance stages of the project lifecycle. In this article we investigate whether linking stages by integrated contracts can lead to more

Sustained maximal voluntary contraction produces independent changes in human motor axons and the muscle they innervate.

Directory of Open Access Journals (Sweden)

David A Milder

Full Text Available The repetitive discharges required to produce a sustained muscle contraction results in activity-dependent hyperpolarization of the motor axons and a reduction in the force-generating capacity of the muscle. We investigated the relationship between these changes in the adductor pollicis muscle and the motor axons of its ulnar nerve supply, and the reproducibility of these changes. Ten subjects performed a 1-min maximal voluntary contraction. Activity-dependent changes in axonal excitability were measured using threshold tracking with electrical stimulation at the wrist; changes in the muscle were assessed as evoked and voluntary electromyography (EMG and isometric force. Separate components of axonal excitability and muscle properties were tested at 5 min intervals after the sustained contraction in 5 separate sessions. The current threshold required to produce the target muscle action potential increased immediately after the contraction by 14.8% (p<0.05, reflecting decreased axonal excitability secondary to hyperpolarization. This was not correlated with the decline in amplitude of muscle force or evoked EMG. A late reversal in threshold current after the initial recovery from hyperpolarization peaked at -5.9% at ∼35 min (p<0.05. This pattern was mirrored by other indices of axonal excitability revealing a previously unreported depolarization of motor axons in the late recovery period. Measures of axonal excitability were relatively stable at rest but less so after sustained activity. The coefficient of variation (CoV for threshold current increase was higher after activity (CoV 0.54, p<0.05 whereas changes in voluntary (CoV 0.12 and evoked twitch (CoV 0.15 force were relatively stable. These results demonstrate that activity-dependent changes in motor axon excitability are unlikely to contribute to concomitant changes in the muscle after sustained activity in healthy people. The variability in axonal excitability after sustained activity

Finite-element simulation of blood perfusion in muscle tissue during compression and sustained contraction

NARCIS (Netherlands)

Vankan, W.J.; Huyghe, J.M.R.J.; Slaaf, D.W.; Donkelaar, van C.C.; Drost, M.R.; Janssen, J.D.; Huson, A.

1997-01-01

Mechanical interaction between tissue stress and blood perfusion in skeletal muscles plays an important role in blood flow impediment during sustained contraction. The exact mechanism of this interaction is not clear, and experimental investigation of this mechanism is difficult. We developed a

Motor Difficulties in Autism Spectrum Disorder: Linking Symptom Severity and Postural Stability

Science.gov (United States)

Travers, Brittany G.; Powell, Patrick S.; Klinger, Laura G.; Klinger, Mark R.

2013-01-01

Postural stability is a fundamental aspect of motor ability that allows individuals to sustain and maintain the desired physical position of one's body. The present study examined postural stability in average-IQ adolescents and adults with Autism Spectrum Disorder (ASD). Twenty-six individuals with ASD and 26 age-and-IQ-matched individuals…

Efficacy of Nintendo Wii Training on Mechanical Leg Muscle Function and Postural Balance in Community-Dwelling Older Adults

DEFF Research Database (Denmark)

Jorgensen, Martin G; Laessoe, Uffe; Hendriksen, Carsten

2013-01-01

BACKGROUND: Older adults show increased risk of falling and major risk factors include impaired lower extremity muscle strength and postural balance. However, the potential positive effect of biofeedback-based Nintendo Wii training on muscle strength and postural balance in older adults is unknown....... METHODS: This randomized controlled trial examined postural balance and muscle strength in community-dwelling older adults (75±6 years) pre- and post-10 weeks of biofeedback-based Nintendo Wii training (WII, n = 28) or daily use of ethylene vinyl acetate copolymer insoles (controls [CON], n = 30). Primary...... end points were maximal muscle strength (maximal voluntary contraction) and center of pressure velocity moment during bilateral static stance. RESULTS: Intention-to-treat analysis with adjustment for age, sex, and baseline level showed that the WII group had higher maximal voluntary contraction...

Postural control and shoulder steadiness in F-16 pilots

DEFF Research Database (Denmark)

Lange, Britt; Murray, Mike; Chreiteh, Shadi S

2014-01-01

to a control group (CG; N = 28) or training group (TG; N = 27). Postural control was tested in four different settings: Romberg with open and closed eyes, unilateral stance, and perturbation. Maximal voluntary contraction and force steadiness was measured for shoulder elevation. RESULTS: At follow......-up, there was a significant between-group difference in the Romberg test with closed eyes only (95% confidence ellipse area; CG: 761 +/- 311 mm2; TG: 650 +/- 405 mm2). Prior to randomization, there were no significant differences in postural control and steadiness between 30 pilots who experienced neck pain within...... the previous 3 mo and 25 pilots without such pain. DISCUSSION: Impaired postural control and steadiness may only be quantifiable in individuals experiencing acute neck pain of certain intensity, and there may be a ceiling effect in the ability to improve these parameters. For individuals with highly developed...

Meta-analysis: association between wrist posture and carpal tunnel syndrome among workers.

Science.gov (United States)

You, Doohee; Smith, Allan H; Rempel, David

2014-03-01

Carpal tunnel syndrome (CTS) is a common work-related peripheral neuropathy. In addition to grip force and repetitive hand exertions, wrist posture (hyperextension and hyperflexion) may be a risk factor for CTS among workers. However, findings of studies evaluating the relationship between wrist posture and CTS are inconsistent. The purpose of this paper was to conduct a meta-analysis of existing studies to evaluate the evidence of the relationship between wrist posture at work and risk of CTS. PubMed and Google Scholar were searched to identify relevant studies published between 1980 and 2012. The following search terms were used: "work related", "carpal tunnel syndrome", "wrist posture", and "epidemiology". The studies defined wrist posture as the deviation of the wrist in extension or flexion from a neutral wrist posture. Relative risk (RR) of individual studies for postural risk was pooled to evaluate the overall risk of wrist posture on CTS. Nine studies met the inclusion criteria. All were cross-sectional or case-control designs and relied on self-report or observer's estimates for wrist posture assessment. The pooled RR of work-related CTS increased with increasing hours of exposure to wrist deviation or extension/flexion [RR = 2.01; 95% confidence interval (CI): 1.646-2.43; p Workplace interventions to prevent CTS should incorporate training and engineering interventions that reduce sustained non-neutral wrist postures.

Postural equilibrium during pregnancy: decreased stability with an increased reliance on visual cues.

Science.gov (United States)

Butler, Erin E; Colón, Iris; Druzin, Maurice L; Rose, Jessica

2006-10-01

The purpose of this study was to determine whether there are changes in postural equilibrium during pregnancy and to examine whether the incidence of falls increases during pregnancy. Static postural balance measures were collected from 12 pregnant women at 11 to 14, 19 to 22, and 36 to 39 weeks gestation and at 6 to 8 weeks after delivery and from 12 nulligravid control subjects who were matched for age, height, weight, and body mass index. Subjects were asked to stand quietly on a stable force platform for 30 seconds with eyes open and closed. Path length and average radial displacement were computed on the basis of the average of 3 trials for each condition. The women were asked at each session if they had sustained a fall in the previous 3 months. Postural stability remained relatively stable during the first trimester; however, second and third trimester and postpartum values for path length and average radial displacement with eyes open and closed were increased significantly compared with the control subjects, which indicates diminished postural balance. The difference between the eyes open and closed values of path length increased as pregnancy progressed. Although 25% of pregnant women sustained falls, none of the control subjects had fallen in the past year. These data suggest that postural stability declines during pregnancy and remains diminished at 6 to 8 weeks after delivery. The study also indicates that there is an increased reliance on visual cues to maintain balance during pregnancy.

The differences in postural reactions between scoliosis and scoliotic posture

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Jacek Wilczyński

2017-05-01

Full Text Available The aim of the research was to demonstrate the differences in amplitudes of postural reactions in girls with scoliotic posture and idiopathic scoliosis. 28 girls aged 7-18 years old were involved in the study. Children attended to the Interschool Centre of Corrective Exercises in Starachowice. The research was conducted in June 2011. Spine research was made by Exhibeon digital radiography. Based on the size of the angle of spinal curvature there were identified: scoliotic posture: 1-9° and scoliosis: ≥10°. Postural reactions were examined by static-dynamic Tecnobody’s ST 310 Plus Stability System platform. There were 21 (75% children with scoliotic posture, and 7 (25% with idiopathic scoliosis. Student's t-test showed a significantly higher postural reactions for scoliosis in relation to scoliotic postures in case of: Average Forward-Backward Speed (OE, (p=0,05, Medium-Lateral Standard Deviation X (CE, (p=0,002, and Ellipse area (CE, (p=0,012. To verify the significant differences, demonstrating the lack of homogeneity of variance, the Mann–Whitney U-test has been used, which showed a significant differences between the scoliotic posture and scoliosis in case of: Medium-Lateral Standard Deviation X (CE, (p=0,0012, Average Forward-Backward Speed (OE, (p=0,0548, and Ellipse area (CE (p=0,0047. Together with an increase of the angle of curvature, the value of these postural reactions also grew. Most of postural reactions didn’t fit the norm.

Sustainable Regulation of Information Sharing with Electronic Data Interchange by a Trust-Embedded Contract

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Guanghua Han

2017-06-01

Full Text Available This paper studies the risks in demand information sharing applications by electronic soft-orders using electronic data interchange (EDI systems in e-commerce and aims to suggest a sustainable regulation mechanism with a trust-embedded contract. In a supply chain with one retailer and one supplier, the retailer solicits private forecasted demand and places soft-orders via EDI to the supplier. To ensure abundant supply, the retailer has an incentive to inflate her soft-orders, which potentially harms the credible information sharing and sustainability of business cooperation. Normally, the degree to which the supplier relies on the retailer’s order information is specified by trust, which is evaluated according to the retailer’s reputation and supplier’s intuition in this study. Based on standard game theory, we find that both the retailer’s order and the quantity of supplier prepared materials are independent of the retailer’s forecast. Therefore, EDI based information sharing in e-commerce without a regulation mechanism leads to inefficient demand information sharing. Since both the supplier and retailer are proved to faces huge of potential profit losses due to the failure of information sharing, the commerce by EDI based information sharing is full of risk and unsustainable. Therefore, a regulation mechanism that leaded by the retailer is proposed to establish ‘win-win’ sustainable cooperation. Numerical experiments highlight the value of trust, the impact of reputation and intuition in decisions, and the effectiveness of the regulation mechanism by a cost-sharing contract.

Does increased postural threat lead to more conscious control of posture?

Science.gov (United States)

Huffman, J L; Horslen, B C; Carpenter, M G; Adkin, A L

2009-11-01

Although it is well established that postural threat modifies postural control, little is known regarding the underlying mechanism(s) responsible for these changes. It is possible that changes in postural control under conditions of elevated postural threat result from a shift to a more conscious control of posture. The purpose of this study was to determine the influence of elevated postural threat on conscious control of posture and to determine the relationship between conscious control and postural control measures. Forty-eight healthy young adults stood on a force plate at two different surface heights: ground level (LOW) and 3.2-m above ground level (HIGH). Centre of pressure measures calculated in the anterior-posterior (AP) direction were mean position (AP-MP), root mean square (AP-RMS) and mean power frequency (AP-MPF). A modified state-specific version of the Movement Specific Reinvestment Scale was used to measure conscious motor processing (CMP) and movement self-consciousness (MSC). Balance confidence, fear of falling, perceived stability, and perceived and actual anxiety indicators were also collected. A significant effect of postural threat was found for movement reinvestment as participants reported more conscious control and a greater concern about their posture at the HIGH height. Significant correlations between CMP and MSC with AP-MP were observed as participants who consciously controlled and were more concerned for their posture leaned further away from the platform edge. It is possible that changes in movement reinvestment can influence specific aspects of posture (leaning) but other aspects may be immune to these changes (amplitude and frequency).

Determining postural stability

Science.gov (United States)

Lieberman, Erez (Inventor); Forth, Katharine E. (Inventor); Paloski, William H. (Inventor)

2011-01-01

A method for determining postural stability of a person can include acquiring a plurality of pressure data points over a period of time from at least one pressure sensor. The method can also include the step of identifying a postural state for each pressure data point to generate a plurality of postural states. The method can include the step of determining a postural state of the person at a point in time based on at least the plurality of postural states.

Discharge characteristics of biceps brachii motor units at recruitment when older adults sustained an isometric contraction.

Science.gov (United States)

Pascoe, Michael A; Holmes, Matthew R; Enoka, Roger M

2011-02-01

The purpose of this study was to compare the discharge characteristics of motor units recruited during an isometric contraction that was sustained with the elbow flexor muscles by older adults at target forces that were less than the recruitment threshold force of each isolated motor unit. The discharge times of 27 single motor units were recorded from the biceps brachii in 11 old adults (78.8 ± 5.9 yr). The target force was set at either a relatively small (6.6 ± 3.7% maximum) or large (11.4 ± 4.5% maximum) difference below the recruitment threshold force and the contraction was sustained until the motor unit was recruited and discharged action potentials for about 60 s. The time to recruitment was longer for the large target-force difference (P = 0.001). At recruitment, the motor units discharged repetitively for both target-force differences, which contrasts with data from young adults when motor units discharged intermittently at recruitment for the large difference between recruitment threshold force and target force. The coefficient of variation (CV) for the first five interspike intervals (ISIs) increased from the small (18.7 ± 7.9) to large difference (35.0 ± 10.2%, P = 0.008) for the young adults, but did not differ for the two target force differences for the old adults (26.3 ± 14.7 to 24.0 ± 13.1%, P = 0.610). When analyzed across the discharge duration, the average CV for the ISI decreased similarly for the two target-force differences (P = 0.618) in old adults. These findings contrast with those of young adults and indicate that the integration of synaptic input during sustained contractions differs between young and old adults.

Response to Niklasson's comment on Lin, et al. (2012) : "the relation between postural movement and bilateral motor integration".

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Lin, Chin-Kai; Kuo, Bor-Chen; Wu, Huey-Min

2014-10-01

In the study of Lin, Wu, Lin, Wu, Wu, Kuo, and Yeung (2012 ), the relationship between the validity of postural movement and bilateral motor integration in terms of sensory integration theory was examined. Postural movement is the ability to use the antigravity postures required for stabilization of the neck, trunk and upper extremities via muscle co-contractions in the neck and upper extremities, and balance. Niklasson's (2013 ) comment argued that postural movement should include primitive reflexes in terms of the general abilities approach. Niklasson (2013 ) focused on the efficacy of the treatment rather than the theoretical frameworks implied in the therapeutic activities. For that purpose Lin, et al. (2012 ) used sensory integration as the theoretical foundation, and the relationship between postural movement and bilateral motor integration was assessed via empirical data. The result of Lin, et al. (2012 ) was offered as a theoretical reference for therapeutic activities.

Chaos in balance: non-linear measures of postural control predict individual variations in visual illusions of motion.

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Deborah Apthorp

Full Text Available Visually-induced illusions of self-motion (vection can be compelling for some people, but they are subject to large individual variations in strength. Do these variations depend, at least in part, on the extent to which people rely on vision to maintain their postural stability? We investigated by comparing physical posture measures to subjective vection ratings. Using a Bertec balance plate in a brightly-lit room, we measured 13 participants' excursions of the centre of foot pressure (CoP over a 60-second period with eyes open and with eyes closed during quiet stance. Subsequently, we collected vection strength ratings for large optic flow displays while seated, using both verbal ratings and online throttle measures. We also collected measures of postural sway (changes in anterior-posterior CoP in response to the same visual motion stimuli while standing on the plate. The magnitude of standing sway in response to expanding optic flow (in comparison to blank fixation periods was predictive of both verbal and throttle measures for seated vection. In addition, the ratio between eyes-open and eyes-closed CoP excursions during quiet stance (using the area of postural sway significantly predicted seated vection for both measures. Interestingly, these relationships were weaker for contracting optic flow displays, though these produced both stronger vection and more sway. Next we used a non-linear analysis (recurrence quantification analysis, RQA of the fluctuations in anterior-posterior position during quiet stance (both with eyes closed and eyes open; this was a much stronger predictor of seated vection for both expanding and contracting stimuli. Given the complex multisensory integration involved in postural control, our study adds to the growing evidence that non-linear measures drawn from complexity theory may provide a more informative measure of postural sway than the conventional linear measures.

Student Friendly Technique to Demonstrate Coordination between Postural (Involuntary) and Voluntary Muscle Contractions.

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Colgan, Wes

2015-01-01

Electromyography is a very useful technique for a number of clinical and research applications in physiology and other life science applications. We have adapted this technique as a student exercise to explore important aspects of postural control. With minimal effort and some mathematical calculations this student friendly technique efficiently demonstrates the interaction of anticipatory, or feedforward, mechanisms and feedback correction from sensory input.

Body posture and postural stability of people practicing qigong

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Jacek Wilczyński

2015-07-01

Full Text Available Introduction: Correct and stable posture is essential for the implementation of the majority of voluntary movements and locomotion. The study of postural stability is an element of clinical trials evaluating physical activity in order to determine the optimal therapeutic procedures. Qigong exercises are not only a form of prevention, helpful in maintaining wellbeing, but also a means of therapy in many diseases, including disorders of postural stability. Aim of the research: To analyse the association between the quality of posture and postural stability of people practicing qigong. Material and methods : The study involved 32 people. The mean age of those tested was 54 years. Posture study used optoelectronic method Diers formetric III 4D. Postural stability was tested on the platform Biodex Balance System. The studies were performed at the Posture Laboratory of the Institute of Physiotherapy at Jan Kochanowski University in Kielce. Results and conclusions : Spearman rank order correlation showed a positive correlation of relative rotation of the spine area with a general indicator of stability (p = 0.0206 at an average level (R = 0.4075 and with the index of the stability A/P (p = 0.0310, although at a lower level (R = 0.3819. With the increase in the relative rotation of the spine area the overall stability indicator and stability indicator A/P also increased. Significant positive correlations were also seen for the surface rotation (+max and a general indication of the stability and the stability index A/P. With the increase of surface rotation (+max of the spine the overall stability indicator and stability indicator A/P also increased.

Effects of flexi-bar and non-flexi-bar exercises on trunk muscles activity in different postures in healthy adults.

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Chung, Jun Sub; Park, Seol; Kim, JiYoung; Park, Ji Won

2015-07-01

[Purpose] The purpose of this study was to assess the effects of flexi-bar exercises and non-flexi-bar exercises on trunk muscle activity in different postures in healthy adults. [Subjects] Twenty healthy right-hand dominant adults (10 males and 10 females) were selected for this study. None of the participants had experienced any orthopedic problems in the spine or in the upper and lower extremities in the previous six months. [Methods] The subjects were instructed to adopt three exercise postures: posture 1, quadruped; posture 2, side-bridge; and posture 3, standing. Surface electromyography of selected trunk muscles was normalized to maximum voluntary isometric contraction. [Results] The external oblique, internal oblique, and erector spinae muscle activity showed significant differences between flexi-bar exercises and non-flexi-bar exercises. [Conclusion] The results of this study suggest that flexi-bar exercises are useful in the activation of trunk muscles.

Dynamic Contraction of the Positive Column of a Self-Sustained Glow Discharge in Molecular Gas Flow

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Shneider, Mikhail

2014-10-01

Contraction of the gas discharge, when current contracts from a significant volume of weakly ionized plasma into a thin arc channel, was attracted attention of scientists for more than a century. Studies of the contraction (also called constriction) mechanisms, besides carrying interesting science, are of practical importance, especially when contraction should be prevented. A set of time-dependent two-dimensional equations for the non-equilibrium weakly-ionized nitrogen/ air plasma is formulated. The process is described by a set of time-dependent continuity equations for the electrons, positive and negative ions; gas and vibrational temperature; by taking into account the convective heat and plasma losses by the transverse flux. Transition from the uniform to contracted state was analyzed. It was shown that such transition experiences a hysteresis, and that the critical current of the transition increases when the pressure (gas density) drops. Possible coexistence of the contracted and uniform state of the plasma in the discharge where the current flows along the density gradient of the background gas was discussed. In this talk the problems related to the dynamic contraction of the current channel inside a quasineutral positive column of a self-sustained glow discharge in molecular gas in a rectangular duct with convection cooling will be discussed. Study presented in this talk was stimulated by the fact that there are large number of experiments on the dynamic contraction of a glow discharge in nitrogen and air flows and a many of possible applications. Similar processes play a role in the powerful gas-discharge lasers. In addition, the problem of dynamic contraction in the large volume of non-equilibrium weakly ionized plasma is closely related to the problem of streamer to leader transitions in lightning and blue jets.

Sustainable kerbside recycling in the municipal garbage contract.

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Chowdhury, Moe

2009-12-01

In an era of global warming, rising energy costs and increasing volumes of wastes destined for landfills and incinerators, communities should set up environmentally sustainable services that are cost-effective for their citizens and revenue generators for municipalities. A win-win garbage collection and kerbside recycling program established more than eight years ago in a small rural community in Ohio, US is still going strong. It is offering a relatively inexpensive way for waste disposal by providing an incentive-based and highly participatory kerbside recycling and at the same time bringing in substantial franchise fees for the municipal coffers. Unlike garbage contracts in most communities that are designed for only residential waste collection, this program extends disposal and recycling services to non-residential establishments. It picks up hard-to-dispose household furniture, appliances and other bulky items without additional costs to the residents. By being creative and assessing local political and socio-economic milieu, public officials can implement a comprehensive service package for taking care of their community throwaways. However, before establishing such programs in partnership with a private firm, city administrators must understand the intricacies of bid specifications customized for municipal wastes and recyclable materials.

Interactions between posture and locomotion: motor patterns in humans walking with bent posture versus erect posture.

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Grasso, R; Zago, M; Lacquaniti, F

2000-01-01

Human erect locomotion is unique among living primates. Evolution selected specific biomechanical features that make human locomotion mechanically efficient. These features are matched by the motor patterns generated in the CNS. What happens when humans walk with bent postures? Are normal motor patterns of erect locomotion maintained or completely reorganized? Five healthy volunteers walked straight and forward at different speeds in three different postures (regular, knee-flexed, and knee- and trunk-flexed) while their motion, ground reaction forces, and electromyographic (EMG) activity were recorded. The three postures imply large differences in the position of the center of body mass relative to the body segments. The elevation angles of the trunk, pelvis, and lower limb segments relative to the vertical in the sagittal plane, the ground reaction forces and the rectified EMGs were analyzed over the gait cycle. The waveforms of the elevation angles along the gait cycle remained essentially unchanged irrespective of the adopted postures. The first two harmonics of these kinematic waveforms explain >95% of their variance. The phase shift but not the amplitude ratio between the first harmonic of the elevation angle waveforms of adjacent pairs was affected systematically by changes in posture. Thigh, shank, and foot angles covaried close to a plane in all conditions, but the plane orientation was systematically different in bent versus erect locomotion. This was explained by the changes in the temporal coupling among the three segments. For walking speeds >1 m s(-1), the plane orientation of bent locomotion indicates a much lower mechanical efficiency relative to erect locomotion. Ground reaction forces differed prominently in bent versus erect posture displaying characteristics intermediate between those typical of walking and those of running. Mean EMG activity was greater in bent postures for all recorded muscles independent of the functional role. The waveforms

SUSTAINED ISOMETRIC SHOULDER CONTRACTION ON MUSCULAR STRENGTH AND ENDURANCE: A RANDOMIZED CLINICAL TRIAL.

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Myers, Natalie L; Toonstra, Jenny L; Smith, Jacob S; Padgett, Cooper A; Uhl, Tim L

2015-12-01

The Advanced Throwers Ten Exercise Program incorporates sustained isometric contractions in conjunction with dynamic shoulder movements. It has been suggested that incorporating isometric holds may facilitate greater increases in muscular strength and endurance. However, no objective evidence currently exists to support this claim. The purpose of this research was to compare the effects of a sustained muscle contraction resistive training program (Advanced Throwers Ten Program) to a more traditional exercise training protocol to determine if increases in shoulder muscular strength and endurance occur in an otherwise healthy population. It was hypothesized that utilizing a sustained isometric hold during a shoulder scaption exercise from the Advanced Throwers Ten would produce greater increases in shoulder strength and endurance as compared to a traditional training program incorporating a isotonic scapular plane abduction (scaption) exercise. Randomized Clinical Trial. Fifty healthy participants were enrolled in this study, of which 25 were randomized into the traditional training group (age: 26 ± 8, height:172 ± 10 cm, weight: 73 ± 13 kg, Marx Activity Scale: 11 ± 4) and 25 were randomized to the Advanced Throwers Ten group (age: 28 ± 9, height: 169 ± 23 cm, weight: 74 ± 16 kg, Marx Activity Scale: 11 ± 5). No pre-intervention differences existed between the groups (P>0.05). Arm endurance and strength data were collected pre and post intervention using a portable load cell (BTE Evaluator, Hanover, MD). Both within and between group analyses were done in order to investigate average torque (strength) and angular impulse (endurance) changes. The traditional and Advanced Throwers Ten groups both significantly improved torque and angular impulse on both the dominant and non-dominant arms by 10-14%. There were no differences in strength or endurance following the interventions between the two training groups (p>0

Cardio-postural interactions and short-arm centrifugation.

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Blaber, Andrew; Goswami, Nandu; Xu, Da; Laurin, Alexendre

INTRODUCTION: We are interested in mechanisms associated with orthostatic tolerance. In previous studies we have shown that postural muscles in the calf contribute to both posture and blood pressure regulation during orthostatic stress. In this study we investigated the relationship between cardiovascular and postural muscle control before, during and after short arm human centrifuge (SAHC) up to 2.2 G. METHODS: Eleven healthy young subjects (6 m, 5 f), with no history of cardiovascular disease, falls or orthostatic hypotension, participated. All were familiarized with the SAHC with 10 minutes at 1-G at the feet. Each subject was instrumented in the supine position on the SAHC for beat-to-beat ECG and blood pressure (Portapres derived SBP). Bilateral lower leg EMG was collected from four leg postural muscles: tibialis anterior, medial gastrocnemius, lateral gastrocnemius, and medial soleus. Transdermal differential recording of signals was performed using an 8-channel EMG system, (Myosystem 1200, Noraxon Inc., Arizona, USA). Postural sway data of the body COP was computed from the force and moment data collected with a force platform (Accusway, AMTI, MA, USA). Before and after SAHC, the subject stood on a force platform with their gaze fixed on a point at eye level, closed their eyes and stood quietly for 5 min. A final stand was conducted 30 min after centrifugation with supine rest in between. During clockwise centrifugation (10-min 1g and 10-min 2.2g at the foot) the subjects’ head was hooded and in the dark. The subject’s body was restrained into the rotation arm with a parachute harness and given additional body support with a foot-plate. ECG, EMG and BP data were collected throughout and centre of pressure trajectory (COP) collected during the stand test. Subjects were requested to relax and not to voluntarily contract the leg muscles; however, they were not to suppress contractions as they occurred involuntarily or by reflex. A Continuous Wavelet

Foot posture influences the electromyographic activity of selected lower limb muscles during gait

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Menz Hylton B

2009-11-01

Full Text Available Abstract Background Some studies have found that flat-arched foot posture is related to altered lower limb muscle function compared to normal- or high-arched feet. However, the results from these studies were based on highly selected populations such as those with rheumatoid arthritis. Therefore, the objective of this study was to compare lower limb muscle function of normal and flat-arched feet in people without pain or disease. Methods Sixty adults aged 18 to 47 years were recruited to this study. Of these, 30 had normal-arched feet (15 male and 15 female and 30 had flat-arched feet (15 male and 15 female. Foot posture was classified using two clinical measurements (the arch index and navicular height and four skeletal alignment measurements from weightbearing foot x-rays. Intramuscular fine-wire electrodes were inserted into tibialis posterior and peroneus longus under ultrasound guidance, and surface EMG activity was recorded from tibialis anterior and medial gastrocnemius while participants walked barefoot at their self-selected comfortable walking speed. Time of peak amplitude, peak and root mean square (RMS amplitude were assessed from stance phase EMG data. Independent samples t-tests were performed to assess for significant differences between the normal- and flat-arched foot posture groups. Results During contact phase, the flat-arched group exhibited increased activity of tibialis anterior (peak amplitude; 65 versus 46% of maximum voluntary isometric contraction and decreased activity of peroneus longus (peak amplitude; 24 versus 37% of maximum voluntary isometric contraction. During midstance/propulsion, the flat-arched group exhibited increased activity of tibialis posterior (peak amplitude; 86 versus 60% of maximum voluntary isometric contraction and decreased activity of peroneus longus (RMS amplitude; 25 versus 39% of maximum voluntary isometric contraction. Effect sizes for these significant findings ranged from 0.48 to 1

Postural orientation and equilibrium processes associated with increased postural sway in autism spectrum disorder (ASD).

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Wang, Zheng; Hallac, Rami R; Conroy, Kaitlin C; White, Stormi P; Kane, Alex A; Collinsworth, Amy L; Sweeney, John A; Mosconi, Matthew W

2016-01-01

Increased postural sway has been repeatedly documented in children with autism spectrum disorder (ASD). Characterizing the control processes underlying this deficit, including postural orientation and equilibrium, may provide key insights into neurophysiological mechanisms associated with ASD. Postural orientation refers to children's ability to actively align their trunk and head with respect to their base of support, while postural equilibrium is an active process whereby children coordinate ankle dorsi-/plantar-flexion and hip abduction/adduction movements to stabilize their upper body. Dynamic engagement of each of these control processes is important for maintaining postural stability, though neither postural orientation nor equilibrium has been studied in ASD. Twenty-two children with ASD and 21 age and performance IQ-matched typically developing (TD) controls completed three standing tests. During static stance, participants were instructed to stand as still as possible. During dynamic stances, participants swayed at a comfortable speed and magnitude in either anterior-posterior (AP) or mediolateral (ML) directions. The center of pressure (COP) standard deviation and trajectory length were examined to determine if children with ASD showed increased postural sway. Postural orientation was assessed using a novel virtual time-to-contact (VTC) approach that characterized spatiotemporal dimensions of children's postural sway (i.e., body alignment) relative to their postural limitation boundary, defined as the maximum extent to which each child could sway in each direction. Postural equilibrium was quantified by evaluating the amount of shared or mutual information of COP time series measured along the AP and ML directions. Consistent with prior studies, children with ASD showed increased postural sway during both static and dynamic stances relative to TD children. In regard to postural orientation processes, children with ASD demonstrated reduced spatial

Body posture modulates action perception.

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Zimmermann, Marius; Toni, Ivan; de Lange, Floris P

2013-04-03

Recent studies have highlighted cognitive and neural similarities between planning and perceiving actions. Given that action planning involves a simulation of potential action plans that depends on the actor's body posture, we reasoned that perceiving actions may also be influenced by one's body posture. Here, we test whether and how this influence occurs by measuring behavioral and cerebral (fMRI) responses in human participants predicting goals of observed actions, while manipulating postural congruency between their own body posture and postures of the observed agents. Behaviorally, predicting action goals is facilitated when the body posture of the observer matches the posture achieved by the observed agent at the end of his action (action's goal posture). Cerebrally, this perceptual postural congruency effect modulates activity in a portion of the left intraparietal sulcus that has previously been shown to be involved in updating neural representations of one's own limb posture during action planning. This intraparietal area showed stronger responses when the goal posture of the observed action did not match the current body posture of the observer. These results add two novel elements to the notion that perceiving actions relies on the same predictive mechanism as planning actions. First, the predictions implemented by this mechanism are based on the current physical configuration of the body. Second, during both action planning and action observation, these predictions pertain to the goal state of the action.

Analysis of the postural stability in individuals with or without signs and symptoms of temporomandibular disorder.

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Ries, Lilian Gerdi Kittel; Bérzin, Fausto

2008-01-01

The objective of this study was to evaluate the stability and the distribution of weight of individuals with TMD (Temporomandibular Disorder) when placed in an orthostatic position. Forty female volunteers, participating in this study, were distributed into a control and a TMD group. Clinical examinations of the craniomandibular system and of the neck were performed. Postural stability was evaluated using a stabilographic platform. Through this system, the sway index (SI), the maximum medial-lateral distance (MMLD), the maximum anterior-posterior distance (MAPD) and the medial-lateral symmetry (MLS) could be determined. Tests were performed in the mandibular rest position and during isometric and isotonic contraction. The variables were analyzed through repeated measures ANOVA. The level of significance was p cervical region (p postural asymmetry, and cervical pain demonstrated a potential link with an increase in postural stability.

[Evaluation of the electromyography activity of pelvic floor muscle during postural exercises using the Wii Fit Plus©. Analysis and perspectives in rehabilitation].

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Steenstrup, B; Giralte, F; Bakker, E; Grise, P

2014-12-01

The aim of this work was to evaluate the effect of postural awareness by using the Wii Fit Plus© on the quality of the baseline (automatic) activity of the pelvic floor muscles (PFM) measured by intravaginal surface electromyography (sEMG). Four healthy continent female subjects, all able to perform a voluntary contraction, undertook 2 sets of 3 various exercises offered by the software Wii Fit Plus© using the Wii balance board© (WBB): one set without any visual control and the second set with postural control and sEMG visual feedback. Simultaneously, we recorded the sEMG activity of the PFM. Mean baseline activity of PFM in standing position at start was 2.87 mV, at submaximal voluntary contraction the sEMG activity raised at a mean of 14.43 mV (7.87-21.89). In the first set of exercises on the WBB without any visual feedback, the automatic activity of the PFM increased from 2.87 mV to 8.75 mV (7.96-9.59). In the second set, with visual postural and sEMG control, mean baseline sEMG activity even raised at 11.39 mV (10.17-11.58). Among women able of a voluntary contraction of PFM, visualisation of posture with the help of the WBB and of sEMG activity of the PFM during static and dynamic Wii Fit Plus© activities, may improve the automatic activation of the PFMs. 4. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

48 CFR 923.103 - Contract clauses.

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2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 923.103... Contract clauses. Insert the clause at 952.223-78, Sustainable Acquisition Program, or its Alternate I, in all contracts under which the contractor operates Government-owned facilities or Government-owned...

A Model for Sustainable Building Energy Efficiency Retrofit (BEER) Using Energy Performance Contracting (EPC) Mechanism for Hotel Buildings in China

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Xu, Pengpeng

Hotel building is one of the high-energy-consuming building types, and retrofitting hotel buildings is an untapped solution to help cut carbon emissions contributing towards sustainable development. Energy Performance Contracting (EPC) has been promulgated as a market mechanism for the delivery of energy efficiency projects. EPC mechanism has been introduced into China relatively recently, and it has not been implemented successfully in building energy efficiency retrofit projects. The aim of this research is to develop a model for achieving the sustainability of Building Energy Efficiency Retrofit (BEER) in hotel buildings under the Energy Performance Contracting (EPC) mechanism. The objectives include: • To identify a set of Key Performance Indicators (KPIs) for measuring the sustainability of BEER in hotel buildings; • To identify Critical Success Factors (CSFs) under EPC mechanism that have a strong correlation with sustainable BEER project; • To develop a model explaining the relationships between the CSFs and the sustainability performance of BEER in hotel building. Literature reviews revealed the essence of sustainable BEER and EPC, which help to develop a conceptual framework for analyzing sustainable BEER under EPC mechanism in hotel buildings. 11 potential KPIs for sustainable BEER and 28 success factors of EPC were selected based on the developed framework. A questionnaire survey was conducted to ascertain the importance of selected performance indicators and success factors. Fuzzy set theory was adopted in identifying the KPIs. Six KPIs were identified from the 11 selected performance indicators. Through a questionnaire survey, out of the 28 success factors, 21 Critical Success Factors (CSFs) were also indentified. Using the factor analysis technique, the 21 identified CSFs in this study were grouped into six clusters to help explain project success of sustainable BEER. Finally, AHP/ANP approach was used in this research to develop a model to

Effects of changes in skiing posture on the kinetics of the knee joint.

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Koyanagi, Maki; Shino, Konsei; Yoshimoto, Yoji; Inoue, Satoru; Sato, Mutsumi; Nakata, Ken

2006-01-01

This study was performed to investigate the effects of changes in the skiing posture on mechanical stress across the knee joint. The aim of the present study was to establish a safer form of skiing for the prevention of injury to the anterior cruciate ligament of the knee (ACL). Ten healthy volunteers were placed on a force plate on an artificial slope, and assumed forward and backward bending postures with a single leg by changing their centre of gravity. The knee flexion angles were limited to approximately 30 degrees by orthotics in each posture. Joint moments of the lower extremity were analyzed using a motion analysis system, and the muscle activities of the lower extremity were recorded by EMG and digitised to integrated EMG in each posture. In addition, extrusion of the lower leg by the boot was measured using a force sensor sheet inserted behind the calf. We found that the extension moment of the hip and ankle joints, and muscular activity of the hamstrings were increased in forward bending, whereas the extension moment of the knee and muscular activity of the quadriceps were decreased. Conversely, the muscular activity of the quadriceps, the flexion moment of the hip, extension moment of the knee joint, and pressure of the boot were increased in backward bending, whereas muscular activity of the hamstrings was decreased. The dependency on the hamstrings increased in forward bending in a skiing posture on a slope with slight knee flexion. Therefore, forward bending seemed to be an advantageous posture for the prevention of ACL injury. Conversely, in a backward bending skiing posture, the extension moment of the knee joint produced by muscle contraction of the quadriceps also increased imbalance in the hamstrings. The results of this study suggest that the internal force exerted by the quadriceps, in addition to the passive factor of extrusion of the lower leg by the boot, may contribute to non-contact ACL injury in a backward bending posture while skiing.

Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight.

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Murray, Mike; Lange, Britt; Chreiteh, Shadi Samir; Olsen, Henrik Baare; Nørnberg, Bo Riebeling; Boyle, Eleanor; Søgaard, Karen; Sjøgaard, Gisela

2016-04-01

Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB) and performing search and rescue (SAR). SAR was performed with Night Vision Goggles (NVG), while AB was performed with (AB+NVG) and without NVG (AB-NVG). EMG was recorded for: trapezius (TRA), upper neck extensors (UNE), and sternocleido-mastoid (SCM). Maximal voluntary contractions (MVC) were performed for normalization of EMG (MVE). Neck posture of pilots and crew-members was monitored and pain intensity of neck, shoulder, and back was recorded. Mean muscle activity for UNE was ∼10% MVE and significantly higher than TRA and SCM, and SCM was significantly lower than TRA. There was no significant difference between AB-NVG and AB+NVG. Muscle activity in the UNE was significantly higher during SAR+NVG than AB-NVG. Sortie time (%) with non-neutral neck posture for SAR+NVG and AB-NVG was: 80.4%, 74.5% (flexed), 55.5%, 47.9% (rotated), 4.5%, 3.7% (lateral flexed). Neck pain intensity increased significantly from pre- (0.7±1.3) to post-sortie (1.6±1.9) for pilots (p=0.028). If sustained, UNE activity of ∼10% MVE is high, and implies a risk for neck disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can Conservation Contracts Co-exist with Change? Payment for Ecosystem Services in the Context of Adaptive Decision-Making and Sustainability

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Hayes, Tanya; Murtinho, Felipe; Cárdenas Camacho, Luis Mario; Crespo, Patricio; McHugh, Sarah; Salmerón, David

2015-01-01

This paper considers the ability of payment for ecosystem services (PES) programs to operate in the context of dynamic and complex social-ecological systems. Drawing on the experiences of two different PES programs in Latin America, we examine how PES institutions fit with the tenets of adaptive decision-making for sustainable resource management. We identify how the program goals and the connection to the market influence the incentive structure, information gathering, learning and feedback processes, and the structure of decision-making rights, specifically the ability to make and modify resource-use rules. Although limited in their generalizability, findings from the two case studies suggest a tension between the contractual model of PES and adaptive decision-making in natural resource systems. PES programs are not inherently decentralized, flexible management tools, as PES contracts tend to restrict decision-making rights and offer minimal flexibility mechanisms to change resource-use practices over the duration of the contract period. Furthermore, PES design and flexibility is heavily dependent on the goals and mission of the buyer and the respective market. If PES is to facilitate sustainable resource management, greater attention is needed to assess how the institutional design of the PES contracts influence the motivation and capacity of participants and program officers alike to adaptively manage the respective resource systems.

Can conservation contracts co-exist with change? Payment for ecosystem services in the context of adaptive decision-making and sustainability.

Science.gov (United States)

Hayes, Tanya; Murtinho, Felipe; Cárdenas Camacho, Luis Mario; Crespo, Patricio; McHugh, Sarah; Salmerón, David

2015-01-01

This paper considers the ability of payment for ecosystem services (PES) programs to operate in the context of dynamic and complex social-ecological systems. Drawing on the experiences of two different PES programs in Latin America, we examine how PES institutions fit with the tenets of adaptive decision-making for sustainable resource management. We identify how the program goals and the connection to the market influence the incentive structure, information gathering, learning and feedback processes, and the structure of decision-making rights, specifically the ability to make and modify resource-use rules. Although limited in their generalizability, findings from the two case studies suggest a tension between the contractual model of PES and adaptive decision-making in natural resource systems. PES programs are not inherently decentralized, flexible management tools, as PES contracts tend to restrict decision-making rights and offer minimal flexibility mechanisms to change resource-use practices over the duration of the contract period. Furthermore, PES design and flexibility is heavily dependent on the goals and mission of the buyer and the respective market. If PES is to facilitate sustainable resource management, greater attention is needed to assess how the institutional design of the PES contracts influence the motivation and capacity of participants and program officers alike to adaptively manage the respective resource systems.

Finite-element simulation of blood perfusion in muscle tissue during compression and sustained contraction.

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Vankan, W J; Huyghe, J M; Slaaf, D W; van Donkelaar, C C; Drost, M R; Janssen, J D; Huson, A

1997-09-01

Mechanical interaction between tissue stress and blood perfusion in skeletal muscles plays an important role in blood flow impediment during sustained contraction. The exact mechanism of this interaction is not clear, and experimental investigation of this mechanism is difficult. We developed a finite-element model of the mechanical behavior of blood-perfused muscle tissue, which accounts for mechanical blood-tissue interaction in maximally vasodilated vasculature. Verification of the model was performed by comparing finite-element results of blood pressure and flow with experimental measurements in a muscle that is subject to well-controlled mechanical loading conditions. In addition, we performed simulations of blood perfusion during tetanic, isometric contraction and maximal vasodilation in a simplified, two-dimensional finite-element model of a rat calf muscle. A vascular waterfall in the venous compartment was identified as the main cause for blood flow impediment both in the experiment and in the finite-element simulations. The validated finite-element model offers possibilities for detailed analysis of blood perfusion in three-dimensional muscle models under complicated loading conditions.

Load type influences motor unit recruitment in biceps brachii during a sustained contraction.

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Baudry, Stéphane; Rudroff, Thorsten; Pierpoint, Lauren A; Enoka, Roger M

2009-09-01

Twenty subjects participated in four experiments designed to compare time to task failure and motor-unit recruitment threshold during contractions sustained at 15% of maximum as the elbow flexor muscles either supported an inertial load (position task) or exerted an equivalent constant torque against a rigid restraint (force task). Subcutaneous branched bipolar electrodes were used to record single motor unit activity from the biceps brachii muscle during ramp contractions performed before and at 50 and 90% of the time to failure for the position task during both fatiguing contractions. The time to task failure was briefer for the position task than for the force task (P=0.0002). Thirty and 29 motor units were isolated during the force and position tasks, respectively. The recruitment threshold declined by 48 and 30% (P=0.0001) during the position task for motor units with an initial recruitment threshold below and above the target force, respectively, whereas no significant change in recruitment threshold was observed during the force task. Changes in recruitment threshold were associated with a decrease in the mean discharge rate (-16%), an increase in discharge rate variability (+40%), and a prolongation of the first two interspike intervals (+29 and +13%). These data indicate that there were faster changes in motor unit recruitment and rate coding during the position task than the force task despite a similar net muscle torque during both tasks. Moreover, the results suggest that the differential synaptic input observed during the position task influences most of the motor unit pool.

Guide to Good Posture

Science.gov (United States)

... you are moving or still, can prevent pain, injuries, and other health problems. What is posture? Posture is how you hold your body. There are two types: Dynamic posture is how you hold yourself when you are moving, like when you are walking, running, or bending over to pick up something. Static ...

Comparison of the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy young women.

Science.gov (United States)

Shirazi, Zahra Rojhani; Jahromi, Fatemeh Nikhalat

2013-09-01

The maintenance of balance is an essential requirement for the performance of daily tasks and sporting activities and muscular fatigue is a factor to impair postural control, so this study was done to compare the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy subjects. Fifteen healthy female students (24.3 ± 2.6 years) completed three testing session with a break period of at least 2 days. During each session, postural control was assessed during two 30-s trials of bipedal stance with eyes close before and after the fatigue protocol. Fatigue protocols were performed by 60% of their unfatigued Maximum Voluntary Contraction of unilateral ankle plantar flexors, bilateral lumbar extensors and bilateral neck extensors. One of the three fatigue protocols was performed on each session. The result showed that fatigue had a significant effect on COP velocity and it increase COP velocity but there was not found any difference in postural sway between muscle groups. Localized muscle fatigue caused deficits in postural control regardless of the location of fatigue. Authors suggest the possibility of the contributions of central mechanisms to postural deficits due to fatigue and it seems that difference was not between muscle groups due to central fatigue.

Somatic features and body posture in children with scoliosis and scoliotic posture

Directory of Open Access Journals (Sweden)

Jacek Wilczyński

2017-08-01

Full Text Available Abstract The aim of the study was to evaluate the relationship between somatic features and body posture in children with scoliosis and scoliotic posture. The study included 28 girls aged 7-18 with scoliosis and scoliotic posture. The selection of the subjects was deliberate. Height measurements were conducted with an anthropometer and weight measurements were done with an electronic scale. Body posture tests were performed using Exhibeon 3D digital photogrammetry and digital radiographs. The significant Spearman correlations between postural variables for the sagittal plane and the somatic variables regarded: trunk inclination angle and BMI (R= 0,4553, p= p=0,015, Abs of the trunk inclination angle and BMI (R = 0.5522, p = 0.002, length of thoracic kyphosis and BMI (R=0,4147, p=0.028, lumbar lordosis and BMI (R=0,4509, p=0,016. The significant Spearman correlations between scoliotic posture variables and the somatic variables concerned: length of primary lordosis and body height (R =0,4923, p=0.008, the length of the primary lordosis and body mass (R = 0.3932, p = 0.038, the length of the primary lordosis and BMI (R=0,4923, p=0.008. Variation analysis regarding postural (Exhibeon and somatic variables showed significant correlations between the direction of the primary curvature and body mass (p=0,0432, body height and primary angle location (p=0,0290 and between the height of the body and the location of the secondary angle (p = 0,0278.

Improving gross motor function and postural control with hippotherapy in children with Down syndrome: case reports.

Science.gov (United States)

Champagne, Danielle; Dugas, Claude

2010-11-01

The purpose of this case report is to describe the impact of an 11-week hippotherapy program on the gross motor functions of two children (respectively 28 and 37 months old) diagnosed with Down syndrome. Hippotherapy is a strategy that uses the horse's motion to stimulate and enhance muscle contraction and postural control. The children were assessed by the Gross Motor Function Measure (GMFM) and accelerometry. The results indicate that both children improved on many dimensions of the GMFM. Power spectral analysis of the acceleration signals showed improvement in postural control of either the head or trunk, because the children adopted two different adaptative strategies to perturbation induced by the moving horse.

41 CFR 102-76.50 - What is sustainable development?

Science.gov (United States)

2010-07-01

... and Construction Sustainable Development § 102-76.50 What is sustainable development? Sustainable... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is sustainable development? 102-76.50 Section 102-76.50 Public Contracts and Property Management Federal Property Management...

Acute Effects of Posture Shirts on Rounded-Shoulder and Forward-Head Posture in College Students.

Science.gov (United States)

Manor, John; Hibberd, Elizabeth; Petschauer, Meredith; Myers, Joseph

2016-12-01

Rounded-shoulder and forward-head posture can be contributing factors to shoulder pain. Corrective techniques such as manual therapy and exercise have been shown to improve these altered postures, but there is little evidence that corrective garments such as posture shirts can alter posture. To determine the acute effects of corrective postureshirt use on rounded-shoulder and forward-head posture in asymptomatic college students. Repeated-measures intervention study with counterbalanced conditions. Research laboratory. 24 members of the general student body of a university, 18-25 y old, with a forward shoulder angle (FSA) >52° and no history of upper-extremity surgery, scoliosis, active shoulder pain, or shoulder pain in the previous 3 mo that restricted participation for 3 consecutive days. Photographic posture assessment under a control condition, under a sham or treatment condition (counterbalanced), under another control condition, and treatment or sham. FSA and forward head angle (FHA) calculated from a lateral photograph. FSA decreased relative to the control condition while participants wore the sham shirt (P = .029) but not the corrective posture shirt (P = 1.00). FHA was unchanged between groups (P = .371). Application of a corrective posture shirt did not acutely alter FSA or FHA, while application of a sham shirt may decrease FSA at rest.

Neck pain and postural balance among workers with high postural demands - a cross-sectional study

DEFF Research Database (Denmark)

Jørgensen, Marie B.; Skotte, Jørgen H.; Holtermann, Andreas

2011-01-01

Neck pain is related to impaired postural balance among patients and is highly prevalent among workers with high postural demands, for example, cleaners. We therefore hypothesised, that cleaners with neck pain suffer from postural dysfunction. This cross-sectional study tested if cleaners with neck...... pain have an impaired postural balance compared with cleaners without neck pain. Postural balance of 194 cleaners with (n = 85) and without (N = 109) neck pain was studied using three different tests. Success or failure to maintain the standing position for 30 s in unilateral stance was recorded...... to cleaners without neck/low back pain (p balance, measured as CEA (p

Neural basis of postural focus effect on concurrent postural and motor tasks: phase-locked electroencephalogram responses.

Science.gov (United States)

Huang, Cheng-Ya; Zhao, Chen-Guang; Hwang, Ing-Shiou

2014-11-01

Dual-task performance is strongly affected by the direction of attentional focus. This study investigated neural control of a postural-suprapostural procedure when postural focus strategy varied. Twelve adults concurrently conducted force-matching and maintained stabilometer stance with visual feedback on ankle movement (visual internal focus, VIF) and on stabilometer movement (visual external focus, VEF). Force-matching error, dynamics of ankle and stabilometer movements, and event-related potentials (ERPs) were registered. Postural control with VEF caused superior force-matching performance, more complex ankle movement, and stronger kinematic coupling between the ankle and stabilometer movements than postural control with VIF. The postural focus strategy also altered ERP temporal-spatial patterns. Postural control with VEF resulted in later N1 with less negativity around the bilateral fronto-central and contralateral sensorimotor areas, earlier P2 deflection with more positivity around the bilateral fronto-central and ipsilateral temporal areas, and late movement-related potential commencing in the left frontal-central area, as compared with postural control with VIF. The time-frequency distribution of the ERP principal component revealed phase-locked neural oscillations in the delta (1-4Hz), theta (4-7Hz), and beta (13-35Hz) rhythms. The delta and theta rhythms were more pronounced prior to the timing of P2 positive deflection, and beta rebound was greater after the completion of force-matching in VEF condition than VIF condition. This study is the first to reveal the neural correlation of postural focusing effect on a postural-suprapostural task. Postural control with VEF takes advantage of efficient task-switching to facilitate autonomous postural response, in agreement with the "constrained-action" hypothesis. Copyright © 2014 Elsevier B.V. All rights reserved.

How does practise of internal Chinese martial arts influence postural reaction control?

Science.gov (United States)

Gorgy, Olivier; Vercher, Jean-Louis; Coyle, Thelma

2008-04-01

The aim of this study was to determine the effects of Chinese martial arts practice on postural reaction control after perturbation. Participants standing in Romberg tandem posture were subjected to an unexpected lateral platform translation with the eyes open or closed at two translation amplitudes. The peak displacement of the centre of pressure and of the centre of mass, and the onset latency of muscular activity (tibialis anterior, gastrocnemius, lumbodorsal muscular group, and rectus abdominis), were evaluated for martial arts practitioners and for sport and non-sport participants. Compared with the sport and non-sport participants, the martial arts group showed lower maximal centre of pressure and centre of mass peak displacements in both the lateral and anterior - posterior directions, but no difference was found in the onset of muscular responses. We conclude that martial arts practice influences postural reaction control during a fixed-support strategy in a tandem task. The martial arts group used the ankle joint more frequently than the sport and non-sport participants, especially in the eyes-closed conditions. Our results suggest that the better balance recovery in the martial arts group is a consequence of better control of biomechanical properties of the lower limbs (e.g. through muscular response by co-contraction), not a change in the neuromuscular temporal pattern.

Study I: effects of 0.06% and 0.10% blood alcohol concentration on human postural control.

Science.gov (United States)

Modig, F; Patel, M; Magnusson, M; Fransson, P A

2012-03-01

Alcohol intoxication causes many accidental falls presented at emergency departments, with the injury severity often related to level of blood alcohol concentration (BAC). One way to evaluate the decline in postural control and the fall risk is to assess standing stability when challenged. The study objective was to comprehensively investigate alcohol-related impairments on postural control and adaptive motor learning at specific BAC levels. Effects of alcohol intoxication at 0.06% and 0.10% BAC were examined with posturography when unperturbed or perturbed by calf vibration. Twenty-five participants (mean age 25.1 years) were investigated standing with either eyes open or closed. Our results revealed several significant findings: (1) stability declined much faster from alcohol intoxication between 0.06% and 0.10% BAC (60-140%) compared with between 0.0% and 0.06% BAC (30%); (2) sustained exposure to repeated balance perturbations augmented the alcohol-related destabilization; (3) there were stronger effects of alcohol intoxication on stability in lateral direction than in anteroposterior direction; and (4) there was a gradual degradation of postural control particularly in lateral direction when the balance perturbations were repeated at 0.06% and 0.10% BAC, indicating adaptation deficits when intoxicated. To summarize, alcohol has profound deteriorating effects on human postural control, which are dose dependent, time dependent and direction specific. The maximal effects of alcohol intoxication on physiological performance might not be evident initially, but may be revealed first when under sustained sensory-motor challenges. Copyright © 2011 Elsevier B.V. All rights reserved.

Should Ballet Dancers Vary Postures and Underfoot Surfaces When Practicing Postural Balance?

Science.gov (United States)

Steinberg, Nili; Waddington, Gordon; Adams, Roger; Karin, Janet; Tirosh, Oren

2018-01-01

Postural balance (PB) is an important component skill for professional dancers. However, the effects of different types of postures and different underfoot surfaces on PB have not adequately been addressed. The main aim of this study was to investigate the effect of different conditions of footwear, surfaces, and standing positions on static and dynamic PB ability of young ballet dancers. A total of 36 male and female young professional ballet dancers (aged 14-19 years) completed static and dynamic balance testing, measured by head and lumbar accelerometers, while standing on one leg in the turnout position, under six different conditions: (1) "relaxed" posture; (2) "ballet" posture; (3) barefoot; (4) ballet shoes with textured insoles; (5) barefoot on a textured mat; and (6) barefoot on a spiky mat. A condition effect was found for static and dynamic PB. Static PB was reduced when dancers stood in the ballet posture compared with standing in the relaxed posture and when standing on a textured mat and on a spiky mat (p ballet shoes with textured insoles and when standing on a spiky mat compared with all other conditions (p ballet aligned position, including dance practice on different types of floors and on different types of textured/spiky materials may result in skill transfer to practice on normal floor surfaces, and both static and dynamic PB exercises should be assessed and generalized into practical dance routines.

Postural Control Disturbances Produced By Exposure to HMD and Dome Vr Systems

Science.gov (United States)

Harm, D. L.; Taylor, L. C.

2005-01-01

Two critical and unresolved human factors issues in VR systems are: 1) potential "cybersickness", a form of motion sickness which is experienced in virtual worlds, and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Most astronauts and cosmonauts experience perceptual and sensorimotor disturbances during and following space flight. All astronauts exhibit decrements in postural control following space flight. It has been suggested that training in virtual reality (VR) may be an effective countermeasure for minimizing perceptual and/or sensorimotor disturbances. People adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, and experimentally-produced stimulus rearrangements (e.g., reversing prisms, magnifying lenses, flight simulators, and VR systems). Adaptation is revealed by aftereffects including perceptual disturbances and sensorimotor control disturbances. The purpose of the current study was to compare disturbances in postural control produced by dome and head-mounted virtual environment displays. Individuals recovered from motion sickness and the detrimental effects of exposure to virtual reality on postural control within one hour. Sickness severity and initial decrements in postural equilibrium decreases over days, which suggests that subjects become dual-adapted over time. These findings provide some direction for developing training schedules for VR users that facilitate adaptation, and address safety concerns about aftereffects.

Mechanisms of repetitive retrograde contractions in response to sustained esophageal distension: a study evaluating patients with postfundoplication dysphagia.

Science.gov (United States)

Carlson, Dustin A; Kahrilas, Peter J; Ritter, Katherine; Lin, Zhiyue; Pandolfino, John E

2018-03-01

Repetitive retrograde contractions (RRCs) in response to sustained esophageal distension are a distinct contractility pattern observed with functional luminal imaging probe (FLIP) panometry that are common in type III (spastic) achalasia. RRCs are hypothesized to be indicative of either impaired inhibitory innervation or esophageal outflow obstruction. We aimed to apply FLIP panometry to patients with postfundoplication dysphagia (a model of esophageal obstruction) to explore mechanisms behind RRCs. Adult patients with dysphagia after Nissen fundoplication ( n = 32) or type III achalasia ( n = 25) were evaluated with high-resolution manometry (HRM) and upper endoscopy with FLIP. HRM studies were assessed for outflow obstruction and spastic features: premature contractility, hypercontractility, and impaired deglutitive inhibition during multiple-rapid swallows. FLIP studies were analyzed to determine the esophagogastric junction (EGJ)-distensibility index and contractility pattern, including RRCs. Barium esophagram was evaluated when available. RRCs were present in 8/32 (25%) fundoplication and 19/25 (76%) achalasia patients ( P esophageal outflow obstruction, as a predictor for RRCs. RRCs in response to sustained esophageal distension appear to be a manifestation of spastic esophageal motility. Although future study to further clarify the significance of RRCs is needed, RRCs on FLIP panometry should prompt evaluation for a major motor disorder. NEW & NOTEWORTHY Repetitive retrograde contractions (RRCs) are a common response to sustained esophageal distension among spastic achalasia patients when evaluated with the functional luminal imaging probe. We evaluated patients with postfundoplication dysphagia, i.e., patients with suspected mechanical obstruction, and found that RRCs occasionally occurred among postfundoplication patients, but often in association with manometric features of esophageal neuromuscular imbalance. Thus, RRCs appear to be a manifestation of

Common postural defects among music students.

Science.gov (United States)

Blanco-Piñeiro, Patricia; Díaz-Pereira, M Pino; Martínez, Aurora

2015-07-01

Postural quality during musical performance affects both musculoskeletal health and the quality of the performance. In this study we examined the posture of 100 students at a Higher Conservatory of Music in Spain. By analysing video tapes and photographs of the students while performing, a panel of experts extracted values of 11 variables reflecting aspects of overall postural quality or the postural quality of various parts of the body. The most common postural defects were identified, together with the situations in which they occur. It is concluded that most students incur in unphysiological postures during performance. It is hoped that use of the results of this study will help correct these errors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermoregulatory postures limit antipredator responses in peafowl.

Science.gov (United States)

Yorzinski, Jessica L; Lam, Jennifer; Schultz, Rachel; Davis, Melissa

2018-01-05

Many animals inhabit environments where they experience temperature fluctuations. One way in which animals can adjust to these temperature changes is through behavioral thermoregulation. However, we know little about the thermal benefits of postural changes and the costs they may incur. In this study, we examined the thermoregulatory role of two postures, the head-tuck and leg-tuck posture, in peafowl ( Pavo cristatus ) and evaluated whether the head-tuck posture imposes a predation cost. The heads and legs of peafowl are significantly warmer when the birds exhibit these postures, demonstrating that these postures serve an important thermoregulatory role. In addition, the birds are slower to respond to an approaching threat when they display the head-tuck posture, suggesting that a thermoregulatory posture can limit antipredator behavior. © 2018. Published by The Company of Biologists Ltd.

Thermoregulatory postures limit antipredator responses in peafowl

Directory of Open Access Journals (Sweden)

Jessica L. Yorzinski

2018-01-01

Full Text Available Many animals inhabit environments where they experience temperature fluctuations. One way in which animals can adjust to these temperature changes is through behavioral thermoregulation. However, we know little about the thermal benefits of postural changes and the costs they may incur. In this study, we examined the thermoregulatory role of two postures, the head-tuck and leg-tuck posture, in peafowl (Pavo cristatus and evaluated whether the head-tuck posture imposes a predation cost. The heads and legs of peafowl are significantly warmer when the birds exhibit these postures, demonstrating that these postures serve an important thermoregulatory role. In addition, the birds are slower to respond to an approaching threat when they display the head-tuck posture, suggesting that a thermoregulatory posture can limit antipredator behavior.

Imaging Posture Veils Neural Signals

Directory of Open Access Journals (Sweden)

Robert T Thibault

2016-10-01

Full Text Available Whereas modern brain imaging often demands holding body positions incongruent with everyday life, posture governs both neural activity and cognitive performance. Humans commonly perform while upright; yet, many neuroimaging methodologies require participants to remain motionless and adhere to non-ecological comportments within a confined space. This inconsistency between ecological postures and imaging constraints undermines the transferability and generalizability of many a neuroimaging assay.Here we highlight the influence of posture on brain function and behavior. Specifically, we challenge the tacit assumption that brain processes and cognitive performance are comparable across a spectrum of positions. We provide an integrative synthesis regarding the increasingly prominent influence of imaging postures on autonomic function, mental capacity, sensory thresholds, and neural activity. Arguing that neuroimagers and cognitive scientists could benefit from considering the influence posture wields on both general functioning and brain activity, we examine existing imaging technologies and the potential of portable and versatile imaging devices (e.g., functional near infrared spectroscopy. Finally, we discuss ways that accounting for posture may help unveil the complex brain processes of everyday cognition.

Membrane depolarization-induced RhoA/Rho-associated kinase activation and sustained contraction of rat caudal arterial smooth muscle involves genistein-sensitive tyrosine phosphorylation

Science.gov (United States)

Mita, Mitsuo; Tanaka, Hitoshi; Yanagihara, Hayato; Nakagawa, Jun-ichi; Hishinuma, Shigeru; Sutherland, Cindy; Walsh, Michael P.; Shoji, Masaru

2013-01-01

Rho-associated kinase (ROK) activation plays an important role in K+-induced contraction of rat caudal arterial smooth muscle (Mita et al., Biochem J. 2002; 364: 431–40). The present study investigated a potential role for tyrosine kinase activity in K+-induced RhoA activation and contraction. The non-selective tyrosine kinase inhibitor genistein, but not the src family tyrosine kinase inhibitor PP2, inhibited K+-induced sustained contraction (IC50 = 11.3 ± 2.4 µM). Genistein (10 µM) inhibited the K+-induced increase in myosin light chain (LC20) phosphorylation without affecting the Ca2+ transient. The tyrosine phosphatase inhibitor vanadate induced contraction that was reversed by genistein (IC50 = 6.5 ± 2.3 µM) and the ROK inhibitor Y-27632 (IC50 = 0.27 ± 0.04 µM). Vanadate also increased LC20 phosphorylation in a genistein- and Y-27632-dependent manner. K+ stimulation induced translocation of RhoA to the membrane, which was inhibited by genistein. Phosphorylation of MYPT1 (myosin-targeting subunit of myosin light chain phosphatase) was significantly increased at Thr855 and Thr697 by K+ stimulation in a genistein- and Y-27632-sensitive manner. Finally, K+ stimulation induced genistein-sensitive tyrosine phosphorylation of proteins of ∼55, 70 and 113 kDa. We conclude that a genistein-sensitive tyrosine kinase, activated by the membrane depolarization-induced increase in [Ca2+]i, is involved in the RhoA/ROK activation and sustained contraction induced by K+. Ca2+ sensitization, myosin light chain phosphatase, RhoA, Rho-associated kinase, tyrosine kinase PMID:24133693

Postural Coordination during Socio-motor Improvisation.

Science.gov (United States)

Gueugnon, Mathieu; Salesse, Robin N; Coste, Alexandre; Zhao, Zhong; Bardy, Benoît G; Marin, Ludovic

2016-01-01

Human interaction often relies on socio-motor improvisation. Creating unprepared movements during social interaction is not a random process but relies on rules of synchronization. These situations do not only involve people to be coordinated, but also require the adjustment of their posture in order to maintain balance and support movements. The present study investigated posture in such a context. More precisely, we first evaluated the impact of amplitude and complexity of arm movements on posture in solo situation. Then, we assessed the impact of interpersonal coordination on posture using the mirror game in which dyads performed improvised and synchronized movements (i.e., duo situation). Posture was measured through ankle-hip coordination in medio-lateral and antero-posterior directions (ML and AP respectively). Our results revealed the spontaneous emergence of in-phase pattern in ML direction and antiphase pattern in AP direction for solo and duo situations. These two patterns respectively refer to the simultaneous flexion/extension of the ankles and the hips in the same or opposite direction. It suggests different functional roles of postural coordination patterns in each direction, with in-phase supporting task performance in ML (dynamical stability) and antiphase supporting postural control in AP (mechanical stability). Although amplitude of movement did not influence posture, movement complexity disturbed postural stability in both directions. Conversely, interpersonal coordination promoted postural stability in ML but not in AP direction. These results are discussed in terms of the difference in coupling strength between ankle-hip coordination and interpersonal coordination.

Postural coordination during socio-motor improvisation

Directory of Open Access Journals (Sweden)

Mathieu Gueugnon

2016-08-01

Full Text Available Human interaction often relies on socio-motor improvisation. Creating unprepared movements during social interaction is not a random process but relies on rules of synchronization. These situations do not only involve people to be coordinated, but also require the adjustment of their posture in order to maintain balance and support movements. The present study investigated posture in such a context. More precisely, we first evaluated the impact of amplitude and complexity of arm movements on posture in solo situation. Then, we assessed the impact of interpersonal coordination on posture using the mirror game in which dyads performed improvised and synchronized movements (i.e., duo situation. Posture was measured through ankle-hip coordination in medio-lateral and antero-posterior directions (ML and AP respectively. Our results revealed the spontaneous emergence of in-phase pattern in ML direction and anti-phase pattern in AP direction for solo and duo situations. These two patterns respectively refer to the simultaneous flexion/extension of the ankles and the hips in the same or opposite direction. It suggests different functional roles of postural coordination patterns in each direction, with in-phase supporting task performance in ML (dynamical stability and antiphase supporting postural control in AP (mechanical stability. Although amplitude of movement did not influence posture, movement complexity disturbed postural stability in both directions. Conversely, interpersonal coordination promoted postural stability in ML but not in AP direction. These results are discussed in terms of the difference in coupling strength between ankle-hip coordination and interpersonal coordination.

Detecting altered postural control after cerebral concussion in athletes with normal postural stability

OpenAIRE

Cavanaugh, J; Guskiewicz, K; Giuliani, C; Marshall, S; Mercer, V; Stergiou, N

2005-01-01

Objective: To determine if approximate entropy (ApEn), a regularity statistic from non-linear dynamics, could detect changes in postural control during quiet standing in athletes with normal postural stability after cerebral concussion.

Voluntary drive-dependent changes in vastus lateralis motor unit firing rates during a sustained isometric contraction at 50% of maximum knee extension force.

NARCIS (Netherlands)

de Ruiter, C.J.; Elzinga, M.J.; Verdijk, PW; van Mechelen, W.; de Haan, A.

2004-01-01

The purpose of the present study was to relate the expected inter-subject variability in voluntary drive of the knee extensor muscles during a sustained isometric contraction to the changes in firing rates of single motor units. Voluntary activation, as established with super-imposed electrical

Anatomy and histochemistry of hindlimb flight posture in birds. I. The extended hindlimb posture of shorebirds.

Science.gov (United States)

McFarland, Joshua C; Meyers, Ron A

2008-08-01

Birds utilize one of two hindlimb postures during flight: an extended posture (with the hip and knee joints flexed, while the ankle joint is extended caudally) or a flexed posture (with the hip, knee, and ankle joints flexed beneath the body). American Avocets (Recurvirostra americana) and Black-necked Stilts (Himantopus mexicanus) extend their legs caudally during flight and support them for extended periods. Slow tonic and slow twitch muscle fibers are typically found in muscles functioning in postural support due to the fatigue resistance of these fibers. We hypothesized that a set of small muscles composed of high percentages of slow fibers and thus dedicated to postural support would function in securing the legs in the extended posture during flight. This study examined the anatomy and histochemical profile of eleven hindlimb muscles to gain insight into their functional roles during flight. Contrary to our hypothesis, all muscles possessed both fast twitch and slow twitch or slow tonic fibers. We believe this finding is due to the versatility of dynamic and postural functions the leg muscles must facilitate, including standing, walking, running, swimming, and hindlimb support during flight. Whether birds use an extended or flexed hindlimb flight posture may be related to the aerodynamic effect of leg position or may reflect evolutionary history. (c) 2008 Wiley-Liss, Inc.

Blackcurrant Alters Physiological Responses and Femoral Artery Diameter during Sustained Isometric Contraction

Directory of Open Access Journals (Sweden)

Matthew David Cook

2017-05-01

Full Text Available Blackcurrant is rich in anthocyanins that may affect exercise-induced physiological responses. We examined tissue oxygen saturation, muscle activity, cardiovascular responses and femoral artery diameter during a submaximal sustained isometric contraction. In a randomised, double-blind, crossover design, healthy men (n = 13, age: 25 ± 4 years, BMI: 25 ± 3 kg·m−2, mean ± SD ingested New Zealand blackcurrant (NZBC extract (600 mg∙day−1 CurraNZ™ or placebo (PL for 7-days separated by 14-days washout. Participants produced isometric maximal voluntary contractions (iMVC and a 120-s 30%iMVC of the quadriceps with electromyography (EMG, near-infrared spectroscopy, hemodynamic and ultrasound recordings. There was no effect of NZBC extract on iMVC (NZBC: 654 ± 73, PL: 650 ± 78 N. During the 30%iMVC with NZBC extract, total peripheral resistance, systolic, diastolic, and mean arterial pressure were lower with increased cardiac output and stroke volume. With NZBC extract, EMG root mean square of the vastus medialis and muscle oxygen saturation were lower with higher total haemoglobin. During the 30%iMVC, femoral artery diameter was increased with NZBC extract at 30 (6.9%, 60 (8.2%, 90 (7.7% and 120 s (6.0%. Intake of NZBC extract for 7-days altered cardiovascular responses, muscle oxygen saturation, muscle activity and femoral artery diameter during a 120-s 30%iMVC of the quadriceps. The present study provides insight into the potential mechanisms for enhanced exercise performance with intake of blackcurrant.

Effects of Balance Training on Postural Sway, Leg Extensor Strength, and Jumping Height in Adolescents

Science.gov (United States)

Granacher, Urs; Gollhofer, Albert; Kriemler, Susi

2010-01-01

Deficits in strength of the lower extremities and postural control have been associated with a high risk of sustaining sport-related injuries. Such injuries often occur during physical education (PE) classes and mostly affect the lower extremities. Thus, the objectives of this study were to investigate the effects of balance training on postural…

The dentist's operating posture - ergonomic aspects.

Science.gov (United States)

Pîrvu, C; Pătraşcu, I; Pîrvu, D; Ionescu, C

2014-06-15

The practice of dentistry involves laborious high finesse dental preparations, precision and control in executions that require a particular attention, concentration and patience of the dentist and finally the dentist's physical and mental resistance. The optimal therapeutic approach and the success of practice involve special working conditions for the dentist and his team in an ergonomic environment. The meaning of the posture in ergonomics is the manner in which different parts of the body are located and thus the reports are established between them in order to allow a special task execution. This article discusses the posture adopted by dentists when they work, beginning with the balanced posture and going to different variants of posture. The ideal posture of a dentist gives him, on the one hand the optimal working conditions (access, visibility and control in the mouth) and on the other hand, physical and psychological comfort throughout the execution of the clinical acts. Although the theme of dentist posture is treated with great care and often presented in the undergraduate courses and the continuing education courses on ergonomics in dentistry, many dentists do not know the subject well enough nor the theoretical issues and therefore nor the practical applicability. The risk and perspective of the musculoskeletal disorders related to unbalanced postures should determine the dentists take postural corrective actions and compensation measures in order to limit the negative effects of working in a bad posture.

Relationship between Muscle Function, Muscle Typology and Postural Performance According to Different Postural Conditions in Young and Older Adults.

Science.gov (United States)

Paillard, Thierry

2017-01-01

Although motor output of the postural function clearly influences postural performance in young and older subjects, no relationship has been formally established between them. However, the relationship between lower-extremity muscle strength/power and postural performance is often pointed out, especially in older subjects. In fact, the influence of motor output may vary according to the postural condition considered (e.g., static, dynamic, challenging, disturbing). In static postural condition, there may be a relationship between lower-extremity muscle strength and postural performance when the value of muscle strength is below a certain threshold in older subjects. Above this threshold of muscle strength, this relationship may disappear. In dynamic postural condition, lower-extremity muscle power could facilitate compensatory postural actions, limiting induced body imbalance likely to generate falls in older subjects. In young subjects, there could be a relationship between very early rapid torque of the leg extensor muscles and postural performance. In the case of postural reaction to (external) perturbations, a high percentage of type II muscle fibers could be associated with the ability to react quickly to postural perturbations in young subjects, while it may enable a reduction in the risk of falls in older subjects. In practice, in older subjects, muscle strength and/or power training contributes to reducing the risk of falls, as well as slowing down the involution of muscle typology regarding type II muscle fibers.

Postural risk assessment of mechanised firewood processing.

Science.gov (United States)

Spinelli, Raffaele; Aminti, Giovanni; De Francesco, Fabio

2017-03-01

The study assessed the postural risk of mechanised firewood processing with eight machines, representing the main technology solutions available on the market. Assessment was conducted with the Ovako Working posture Analysis System (OWAS) on 1000 still frames randomly extracted from videotaped work samples. The postural risk associated with firewood processing was variable and associated with technology type. Simple, manually operated new machines incurred a higher postural risk compared with semi- or fully automatic machines. In contrast, new semi-automatic and automatic machines were generally free from postural risk. In all cases, attention should be paid to postural risk that may occur during blockage resolution. The study did not cover the postural risk of firewood processing sites as a whole. The study provided useful information for selecting firewood processing machinery and for improving firewood machinery design, as part of a more articulate strategy aimed at enhancing the safety of firewood processing work sites. Practitioner Summary: The postural risk associated with mechanised firewood processing (eg cutting and splitting) depends on the type of equipment. Postural risk is highest (OWAS Action Category 2) with new in-line machines, designed for operation by a single worker. Fully automatic machines present minimum postural risk, except during blockage resolution.

Efficacy of Nintendo Wii training on mechanical leg muscle function and postural balance in community-dwelling older adults: a randomized controlled trial.

Science.gov (United States)

Jorgensen, Martin G; Laessoe, Uffe; Hendriksen, Carsten; Nielsen, Ole Bruno Faurholt; Aagaard, Per

2013-07-01

Older adults show increased risk of falling and major risk factors include impaired lower extremity muscle strength and postural balance. However, the potential positive effect of biofeedback-based Nintendo Wii training on muscle strength and postural balance in older adults is unknown. This randomized controlled trial examined postural balance and muscle strength in community-dwelling older adults (75±6 years) pre- and post-10 weeks of biofeedback-based Nintendo Wii training (WII, n = 28) or daily use of ethylene vinyl acetate copolymer insoles (controls [CON], n = 30). Primary end points were maximal muscle strength (maximal voluntary contraction) and center of pressure velocity moment during bilateral static stance. Intention-to-treat analysis with adjustment for age, sex, and baseline level showed that the WII group had higher maximal voluntary contraction strength (18%) than the control group at follow up (between-group difference = 269 N, 95% CI = 122; 416, and p = .001). In contrast, the center of pressure velocity moment did not differ (1%) between WII and CON at follow-up (between-group difference = 0.23 mm(2)/s, 95% CI = -4.1; 4.6, and p = .92). For secondary end points, pre-to-post changes favoring the WII group were evident in the rate of force development (p = .03), Timed Up and Go test (p = .01), short Falls Efficacy Scale-International (p = .03), and 30-second repeated Chair Stand Test (p = .01). Finally, participants rated the Wii training highly motivating at 5 and 10 weeks into the intervention. Biofeedback-based Wii training led to marked improvements in maximal leg muscle strength (maximal voluntary contraction; rate of force development) and overall functional performance in community-dwelling older adults. Unexpectedly, static bilateral postural balance remained unaltered with Wii training. The high level of participant motivation suggests that biofeedback-based Wii exercise may ensure a high degree of compliance to home- and/or community

Sustainability as Social Contract: Textile and Apparel Professionals’ Value Conflicts within the Corporate Moral Responsibility Spectrum

Directory of Open Access Journals (Sweden)

Rachel LoMonaco-Benzing

2016-12-01

Full Text Available Current discussions of sustainability in the textile and apparel (T&A supply chain tend to focus on consumer behavior or methods of production. Few studies investigate how T&A supply chain members experience corporate sustainability initiatives within their own moral value spectrum. This study was designed to describe the gaps that might exist between personal and corporate moral values of T&A supply chain members, and how individuals manage such gaps to align personal and corporate identities. The researchers investigated the views of ten T&A supply chain members residing in the United States, both as employees and consumers of T&A companies, through semi-structured interviews. Dunfee’s extant social contracts and Schwartz’s theory of basic values were used as theoretical frameworks to better understand the participants’ lived experiences in negotiating personal and corporate expectations. The findings revealed three themes: (a nature of the value gap; (b frustration due to the value gap; and (c strategies to manage the value gap. The strategies used to realign values split into either those that held sustainability as their responsibility and worked to move corporate values toward their personal values; or those that shifted the blame to others so that their values could remain untouched.

Relationship between postural alignment in sitting by photogrammetry and seated postural control in post-stroke subjects.

Science.gov (United States)

Iyengar, Y R; Vijayakumar, K; Abraham, J M; Misri, Z K; Suresh, B V; Unnikrishnan, B

2014-01-01

This study was executed to find out correlation between postural alignment in sitting measured through photogrammetry and postural control in sitting following stroke. A cross-sectional study with convenient sampling consisting of 45 subjects with acute and sub-acute stroke. Postural alignment in sitting was measured through photogrammetry and relevant angles were obtained through software MB Ruler (version 5.0). Seated postural control was measured through Function in Sitting Test (FIST). Correlation was obtained using Spearman's Rank Correlation co-efficient in SPSS software (version 17.0). Moderate positive correlation (r = 0.385; p < 0.01) was found between angle of lordosis and angle between acromion, lateral epicondyle and point between radius and ulna. Strong negative correlation (r = -0.435; p < 0.01) was found between cranio-vertebral angle and kyphosis. FIST showed moderate positive correlation (r = 0.3446; p < 0.05) with cranio-vertebral angle and strong positive correlation (r = 0.4336; p < 0.01) with Brunnstrom's stage of recovery in upper extremity. Degree of forward head posture in sitting correlates directly with seated postural control and inversely with degree of kyphosis in sitting post-stroke. Postural control in sitting post-stroke is directly related with Brunnstrom's stage of recovery in affected upper extremity in sitting.

Postural stability and the influence of concurrent muscle activation--Beneficial effects of jaw and fist clenching.

Science.gov (United States)

Ringhof, Steffen; Leibold, Timo; Hellmann, Daniel; Stein, Thorsten

2015-10-01

Recent studies reported on the potential benefits of submaximum clenching of the jaw on human postural control in upright unperturbed stance. However, it remained unclear whether these effects might also be observed among active controls. The purpose of the present study, therefore, was to comparatively examine the influence of concurrent muscle activation in terms of submaximum clenching of the jaw and submaximum clenching of the fists on postural stability. Posturographic analyses were conducted with 17 healthy young adults on firm and foam surfaces while either clenching the jaw (JAW) or clenching the fists (FIST), whereas habitual standing served as the control condition (CON). Both submaximum tasks were performed at 25% maximum voluntary contraction, assessed, and visualized in real time by means of electromyography. Statistical analyses revealed that center of pressure (COP) displacements were significantly reduced during JAW and FIST, but with no differences between both concurrent clenching activities. Further, a significant increase in COP displacements was observed for the foam as compared to the firm condition. The results showed that concurrent muscle activation significantly improved postural stability compared with habitual standing, and thus emphasize the beneficial effects of jaw and fist clenching for static postural control. It is suggested that concurrent activities contribute to the facilitation of human motor excitability, finally increasing the neural drive to the distal muscles. Future studies should evaluate whether elderly or patients with compromised postural control might benefit from these physiological responses, e.g., in the form of a reduced risk of falling. Copyright © 2015 Elsevier B.V. All rights reserved.

Botulinum toxin as treatment for focal dystonia : a systematic review of the pharmaco-therapeutic and pharmaco-economic value

NARCIS (Netherlands)

Zoons, E.; Dijkgraaf, M. G. W.; Dijk, J. M.; van Schaik, I. N.; Tijssen, M. A.

2012-01-01

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the

Botulinum toxin as treatment for focal dystonia: a systematic review of the pharmaco-therapeutic and pharmaco-economic value

NARCIS (Netherlands)

Zoons, E.; Dijkgraaf, M. G. W.; Dijk, J. M.; van Schaik, I. N.; Tijssen, M. A.

2012-01-01

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the

On the functional integration between postural and supra-postural tasks on the basis of contextual cues and task constraint.

Science.gov (United States)

de Lima, Andrea Cristina; de Azevedo Neto, Raymundo Machado; Teixeira, Luis Augusto

2010-10-01

In order to evaluate the effects of uncertainty about direction of mechanical perturbation and supra-postural task constraint on postural control, young adults had their upright stance perturbed while holding a tray in a horizontal position. Stance was perturbed by moving forward or backward a supporting platform, contrasting situations of certainty versus uncertainty of direction of displacement. Increased constraint on postural stability was imposed by a supra-postural task of equilibrating a cylinder on the tray. Performance was assessed through EMG of anterior leg muscles, angular displacement of the main joints involved in the postural reactions and displacement of the tray. Results showed that both certainty on the direction of perturbation and increased supra-postural task constraint led to decreased angular displacement of the knee and the hip. Furthermore, combination of certainty and high supra-postural task constraint produced shorter latency of muscular activation. Such postural responses were paralleled by decreased displacement of the tray. These results suggest a functional integration between the tasks, with central set priming reactive postural responses from contextual cues and increased stability demand. Copyright © 2010 Elsevier B.V. All rights reserved.

Neck pain and postural balance among workers with high postural demands - a cross-sectional study

Science.gov (United States)

2011-01-01

Background Neck pain is related to impaired postural balance among patients and is highly prevalent among workers with high postural demands, for example, cleaners. We therefore hypothesised, that cleaners with neck pain suffer from postural dysfunction. This cross-sectional study tested if cleaners with neck pain have an impaired postural balance compared with cleaners without neck pain. Methods Postural balance of 194 cleaners with (n = 85) and without (N = 109) neck pain was studied using three different tests. Success or failure to maintain the standing position for 30 s in unilateral stance was recorded. Participants were asked to stand on a force platform for 30 s in the Romberg position with eyes open and closed. The centre of pressure of the sway was calculated, and separated into a slow (rambling) and fast (trembling) component. Subsequently, the 95% confidence ellipse area (CEA) was calculated. Furthermore a perturbation test was performed. Results More cleaners with neck pain (81%) failed the unilateral stance compared with cleaners without neck pain (61%) (p neck pain in comparison with cleaners without neck pain in the Romberg position with eyes closed, but not with eyes open. Conclusions Postural balance is impaired among cleaners with neck pain and the current study suggests a particular role of the slow component of postural sway. Furthermore, the unilateral stance test is a simple test to illustrate functional impairment among cleaners with concurrent neck and low back pain. Trial registration ISRCTN96241850 PMID:21806796

Automated Assessment of Postural Stability (AAPS)

Science.gov (United States)

2016-10-01

performed a battery of standard clinical tests of dynamic posture, whereas the fourth subject performed the stereotyped postures (e.g. movements restricted...Processing & Control [2] Napoli A, Ward C, Glass S, Tucker C, Obeid I (2016) “Automated Assessment of Postural Stability System,” IEEE Engineering in

Gait, posture and cognition in Parkinson's disease

Directory of Open Access Journals (Sweden)

Alessandra Ferreira Barbosa

Full Text Available ABSTRACT Gait disorders and postural instability are the leading causes of falls and disability in Parkinson's disease (PD. Cognition plays an important role in postural control and may interfere with gait and posture assessment and treatment. It is important to recognize gait, posture and balance dysfunctions by choosing proper assessment tools for PD. Patients at higher risk of falling must be referred for rehabilitation as early as possible, because antiparkinsonian drugs and surgery do not improve gait and posture in PD.

Postural Control in Children with Autism.

Science.gov (United States)

Kohen-Raz, Reuven; And Others

1992-01-01

Postural control was evaluated in 91 autistic, 166 normal, and 18 mentally retarded children using a computerized posturographic procedure. In comparison to normal children, the autistic subjects were less likely to exhibit age-related changes in postural performance, and postures were more variable and less stable. (Author/JDD)

Dynamic stability control in forward falls: postural corrections after muscle fatigue in young and older adults.

Science.gov (United States)

Mademli, Lida; Arampatzis, Adamantios; Karamanidis, Kiros

2008-06-01

Many studies report that muscle strength loss may alter the human system's capacity to generate rapid force for balance corrections after perturbations, leading to deficient recovery behaviours. Yet little is known regarding the effect of modifications in the neuromuscular system induced by fatigue on dynamic stability control during postural perturbations. This study investigates the effect of muscle strength decline induced by fatiguing contractions on the dynamic stability control of young and older adults during forward falls. Eleven young and eleven older male adults had to regain balance after sudden falls before and after submaximal fatiguing knee extension-flexion contractions. Young subjects had a higher margin of stability than older ones before and after the fatiguing task. This reflects their enhanced ability in using mechanisms for maintaining dynamic stability (i.e. a greater base of support). The margin of stability, the boundary of the base of support and the position of the extrapolated centre of mass, remained unaffected by the reduction in muscle strength induced by the fatiguing contractions, indicating an appropriate adjustment of the motor commands to compensate the deficit in muscle strength. Both young and older adults were able to counteract the decreased horizontal ground reaction forces after the fatiguing task by flexing their knee to a greater extent, leading to similar decreases in the horizontal velocity of centre of mass as in the pre fatigue condition. The results demonstrate the ability of the central nervous system to rapidly modify the execution of postural corrections including mechanisms for maintaining dynamic stability.

Kinematics of the human mandible for different head postures.

Science.gov (United States)

Visscher, C M; Huddleston Slater, J J; Lobbezoo, F; Naeije, M

2000-04-01

The influence of head posture on movement paths of the incisal point (IP) and of the mandibular condyles during free open-close movements was studied. Ten persons, without craniomandibular or cervical spine disorders, participated in the study. Open close mandibular movements were recorded with the head in five postures, viz., natural head posture, forward head posture, military posture, and lateroflexion to the right and to the left side, using the Oral Kinesiologic Analysis System (OKAS-3D). This study showed that in a military head posture, the opening movement path of the incisal point is shifted anteriorly relative to the path in a natural head posture. In a forward head posture, the movement path is shifted posteriorly whereas during lateroflexion, it deviates to the side the head has moved to. Moreover, the intra-articular distance in the temporomandibular joint during closing is smaller with the head in military posture and greater in forward head posture, as compared to the natural head posture. During lateroflexion, the intra-articular distance on the ipsilateral side is smaller. The influence of head posture upon the kinematics of the mandible is probably a manifestation of differences in mandibular loading in the different head postures.

The Relationship Between Postural and Movement Stability.

Science.gov (United States)

Feldman, Anatol G

2016-01-01

Postural stabilization is provided by stretch reflexes, intermuscular reflexes, and intrinsic muscle properties. Taken together, these posture-stabilizing mechanisms resist deflections from the posture at which balance of muscle and external forces is maintained. Empirical findings suggest that for each muscle, these mechanisms become functional at a specific, spatial threshold-the muscle length or respective joint angle at which motor units begin to be recruited. Empirical data suggest that spinal and supraspinal centers can shift the spatial thresholds for a group of muscles that stabilized the initial posture. As a consequence, the same stabilizing mechanisms, instead of resisting motion from the initial posture, drive the body to another stable posture. In other words by shifting spatial thresholds, the nervous system converts movement resisting to movement-producing mechanisms. It is illustrated that, contrary to conventional view, this control strategy allows the system to transfer body balance to produce locomotion and other actions without loosing stability at any point of them. It also helps orient posture and movement with the direction of gravity. It is concluded that postural and movement stability is provided by a common mechanism.

Visual Vection does not Perturb Squatting Posture

Directory of Open Access Journals (Sweden)

Dietrich Gilles

2011-12-01

Full Text Available Vision contributes fundamentally to the control of the standing posture. The illusion of self motion falsely perceived (vection increases postural sway while standing. In this paper we examine the effect of vection on both standing and deep squatting with the hypothesis that the squatting posture should not be disturbed by the conflict of sensory information due to vection. The results show that standing posture only was affected by the visual stimuli. The widespread use of squatting for work as well as rest could be due in part to this lack of effect of sensory perturbation on postural stability.

Postural Stability of Patients with Schizophrenia during Challenging Sensory Conditions: Implication of Sensory Integration for Postural Control.

Science.gov (United States)

Teng, Ya-Ling; Chen, Chiung-Ling; Lou, Shu-Zon; Wang, Wei-Tsan; Wu, Jui-Yen; Ma, Hui-Ing; Chen, Vincent Chin-Hung

2016-01-01

Postural dysfunctions are prevalent in patients with schizophrenia and affect their daily life and ability to work. In addition, sensory functions and sensory integration that are crucial for postural control are also compromised. This study intended to examine how patients with schizophrenia coordinate multiple sensory systems to maintain postural stability in dynamic sensory conditions. Twenty-nine patients with schizophrenia and 32 control subjects were recruited. Postural stability of the participants was examined in six sensory conditions of different level of congruency of multiple sensory information, which was based on combinations of correct, removed, or conflicting sensory inputs from visual, somatosensory, and vestibular systems. The excursion of the center of pressure was measured by posturography. Equilibrium scores were derived to indicate the range of anterior-posterior (AP) postural sway, and sensory ratios were calculated to explore ability to use sensory information to maintain balance. The overall AP postural sway was significantly larger for patients with schizophrenia compared to the controls [patients (69.62±8.99); controls (76.53±7.47); t1,59 = -3.28, pmaintain balance compared to the controls.

Education and the Prevention of Postural Defects

Directory of Open Access Journals (Sweden)

Olchowska-Kotala Agnieszka

2014-12-01

Full Text Available Purpose. The aim of this study was to determine: whether and at what stage of education is proper body posture learned, the intention of young adults to participate in activities teaching proper posture, and the effects of factors related with the said intention. Methods. The study involved 430 university students aged 18-24 years. Anthropometric data was collected. Participants completed questionnaires assessing physical activity level (IPAQ and their intention to participate in extracurricular activities teaching proper posture while sitting or walking, proper running technique, corrective gymnastics, or weight loss exercises. A self-assessment of posture, physical fitness, attractiveness, and body satisfaction was also completed. Results. Lower back pain was experienced by 41% of the respondents. Most were taught proper posture-related habits in primary school, followed by secondary school, and then at university. Many students expressed their intention to participate in the extracurricular activities. None of the questionnaire variables were associated with the intention to learn proper walking posture or proper running technique. The intention to participate in classes teaching proper sitting posture was associated with lower back pain in women and low physical activity level in men. In women, a relationship was found between the intention to participate in weight loss exercises and body dissatisfaction, high BMI, and poor self-evaluations of posture and attractiveness. In men, this activity was associated with body dissatisfaction. Conclusions. There is a need for further education on the development of proper postural habits at the university level.

Improvement of posture stability by vibratory stimulation following anterior cruciate ligament reconstruction.

Science.gov (United States)

Brunetti, O; Filippi, G M; Lorenzini, M; Liti, A; Panichi, R; Roscini, M; Pettorossi, V E; Cerulli, G

2006-11-01

Surgical reconstruction of the anterior cruciate ligament (ACL) may reduce, but it does not always eliminate, knee and body instability because of a persisting proprioceptive deficit. In order to enhance body stability, a new protocol of treatment has been proposed consisting of mechanical vibration (100 Hz frequency and < 20 microm amplitude) of the quadriceps muscle in the leg that has undergone ACL reconstruction. In our trials, stimulation was performed when the quadriceps muscle was kept isometrically contracted. Treatment was started one month after surgery. Vibration was applied for short periods over three consecutive days. Nine months after treatment, postural stability was re-evaluated with the subjects standing on one leg with open and with closed eyes. The postural stability of the subjects having undergone vibration treatment, standing on the operated leg was significantly improved one day after treatment when evaluated as mean of speed and elliptic area of the center of pressure. The improvement persisted and increased during the following weeks. Peak torques of the operated leg extensor muscles also increased and reached values close to that of the leg, which had not been operated. Conversely, the balance of the untreated subjects standing on the operated leg did not improve and the restoration of the extensor muscle peak torque was poor. It is concluded that short lasting proprioceptive activation by vibration may lead to a faster and more complete equilibrium recovery probably by permanently changing the network controlling knee posture.

Gait, posture and cognition in Parkinson's disease

OpenAIRE

Barbosa, Alessandra Ferreira; Chen, Janini; Freitag, Fernanda; Valente, Debora; Souza, Carolina de Oliveira; Voos, Mariana Callil; Chien, Hsin Fen

2016-01-01

ABSTRACT Gait disorders and postural instability are the leading causes of falls and disability in Parkinson's disease (PD). Cognition plays an important role in postural control and may interfere with gait and posture assessment and treatment. It is important to recognize gait, posture and balance dysfunctions by choosing proper assessment tools for PD. Patients at higher risk of falling must be referred for rehabilitation as early as possible, because antiparkinsonian drugs and surgery do n...

Postural ortostatisk takykardisyndrom

DEFF Research Database (Denmark)

Brinth, Louise; Pors, Kirsten; Mehlsen, Jesper

2014-01-01

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous condition of dysautonomia and suspected autoimmunity characterized by abnormal increments in heart rate upon assumption of the upright posture accompanied by symptoms of cerebral hypoperfusion and sympathoexcitation. An increase...... in heart rate equal to or greater than 30 bpm or to levels higher than 120 bpm during a head-up tilt test is the main diagnostic criterion. Management includes both non-pharmacological and pharmacological treatment focusing on stress management, volume expansion and heart rate control....

Relationships among head posture, pain intensity, disability and deep cervical flexor muscle performance in subjects with postural neck pain

Directory of Open Access Journals (Sweden)

Arun V. Subbarayalu, PhD

2017-12-01

Full Text Available Objectives: Information Technology (IT professionals working with computers gradually develop forward head posture and, as a result, these professionals are susceptible to several neck disorders. This study intended to reveal the relationships between pain intensity, disability, head posture and deep cervical flexor (DCF muscle performance in patients with postural neck pain. Methods: A cross-sectional study was conducted on 84 IT professionals who were diagnosed with postural neck pain. The participants were recruited with a random sampling approach. A Visual Analogue Scale (VAS, the Northwick Park Neck Pain Questionnaire (NPQ, the Modified Head Posture Spinal Curvature Instrument (MHPSCI, and the Stabilizer Pressure Biofeedback Unit were used to measure neck pain intensity, neck disability, head posture, and DCF muscle performance, respectively. Results: The Pearson correlation coefficient revealed a significantly strong positive relationship between the VAS and the NPQ (r = 0.734. The cranio-vertebral (CV angle was found to have a significantly negative correlation with the VAS (r = −0.536 and a weak negative correlation with the NPQ (r = −0.389. Conclusion: This study concluded that a smaller CV angle corresponded to greater neck pain intensity and disability. Furthermore, there is no significant relationship between CV angle and DCF muscle performance, indicating that head posture re-education through postural correction exercises would not completely correct the motor control deficits in DCF muscles. In addition, a suitable exercise regimen that exclusively targets the deep cervical flexor muscle to improve its endurance is warranted. Keywords: Craniovertebral angle, Disability deep cervical flexors muscle performance, Head posture, Postural neck pain

Taboos and social contracts: Tools for ecosystem management ...

African Journals Online (AJOL)

Traditional taboos and social contracts played an important role in managing the Manambolomaty RAMSAR site. Taboos are defined as a prohibition imposed by social custom as a protective measure' and social contracts are – in conservation sense – a common agreement for achieving conservation, sustainable ...

Thermoregulatory postures limit antipredator responses in peafowl

OpenAIRE

Jessica L. Yorzinski; Jennifer Lam; Rachel Schultz; Melissa Davis

2018-01-01

Many animals inhabit environments where they experience temperature fluctuations. One way in which animals can adjust to these temperature changes is through behavioral thermoregulation. However, we know little about the thermal benefits of postural changes and the costs they may incur. In this study, we examined the thermoregulatory role of two postures, the head-tuck and leg-tuck posture, in peafowl (Pavo cristatus) and evaluated whether the head-tuck posture imposes a predation cost. The h...

Functional Neuroanatomy for Posture and Gait Control

Directory of Open Access Journals (Sweden)

Kaoru Takakusaki

2017-01-01

Full Text Available Here we argue functional neuroanatomy for posture- gait control. Multi-sensory information such as somatosensory, visual and vestibular sensation act on various areas of the brain so that adaptable posture- gait control can be achieved. Automatic process of gait, which is steady-state stepping movements associating with postural reflexes including headeye coordination accompanied by appropriate alignment of body segments and optimal level of postural muscle tone, is mediated by the descending pathways from the brainstem to the spinal cord. Particularly, reticulospinal pathways arising from the lateral part of the mesopontine tegmentum and spinal locomotor network contribute to this process. On the other hand, walking in unfamiliar circumstance requires cognitive process of postural control, which depends on knowledges of self-body, such as body schema and body motion in space. The cognitive information is produced at the temporoparietal association cortex, and is fundamental to sustention of vertical posture and construction of motor programs. The programs in the motor cortical areas run to execute anticipatory postural adjustment that is optimal for achievement of goal-directed movements. The basal ganglia and cerebellum may affect both the automatic and cognitive processes of posturegait control through reciprocal connections with the brainstem and cerebral cortex, respectively. Consequently, impairments in cognitive function by damages in the cerebral cortex, basal ganglia and cerebellum may disturb posture-gait control, resulting in falling.

Enhancing Economic Sustainability by Markdown Money Supply Contracts in the Fashion Industry: China vs U.S.A.

Directory of Open Access Journals (Sweden)

Bin Shen

2015-12-01

Full Text Available Supply chain contracts, such as the markdown money policy (MMP, are commonly adopted in the fashion industry. In this paper, we explore how fashion companies can use MMP to enhance economic sustainability from the cross-cultural perspective. We conduct case studies on two fashion firms (suppliers, one from China and one from U.S.A., that are adopting MMP in their respective supply chains. Via semi-structured interviews with staff members and some public data searching of the target companies, we find that the cultural factors, such as power distance and collectivism/individualism, affect contract selection, contract management, supplier–retailer leadership, and supplier–retailer relationship. We use the Hofstede’s national cultural dimensions theory to explain our insights. Specifically, in China, a country with a relatively high degree of power distance and collectivism, the companies tend to care more about the group interest and loyalty. The Chinese fashion companies are more willing to play the leading role in managing the relationships with their retailers, and offer MMP to them. In the U.S.A., a country with a relatively low degree of power distance and individualism, the companies are more likely to emphasize their own interest in trading. In fact, we find that American fashion suppliers tend to bargain with their retailers, and they are less willing to proactively provide the markdown money as a sponsor. Finally, managerial implications are provided, and several future challenges on MMP are examined.

Postural stability and occlusal status among Japanese elderly.

Science.gov (United States)

Song-Yu, Xuan; Rodis, Omar M M; Ogata, Sagiri; Can-Hu, Jin; Nishimura, Michiko; Matsumura, Seishi

2012-06-01

There are still no data available on the relationship between postural stability and occlusal status among the elderly. To examine relationships between postural stability and occlusal status through a cohort study among elderly Japanese. Oral examination, occlusal status, postural stability and a questionnaire were conducted and given to 87 community-dwelling Japanese at enrolment. The average occlusal pressure of the female group was statistically higher than the male group while average occlusal pressure and postural stability length were lesser in the group with more remaining teeth. Postural stability area and number of remaining teeth showed statistically significant correlations. Postural stability length was lesser in the group with strong occlusal force. Furthermore, the number of decayed teeth was fewer in the good hygiene group. This study identified a close relationship between occlusal status and postural stability of Japanese older individuals. Occlusal hypofunction was observed more in those with occlusal problems, and a decrease in their occlusal functions resulted in postural instability. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Postural Stability of Patients with Schizophrenia during Challenging Sensory Conditions: Implication of Sensory Integration for Postural Control.

Directory of Open Access Journals (Sweden)

Ya-Ling Teng

Full Text Available Postural dysfunctions are prevalent in patients with schizophrenia and affect their daily life and ability to work. In addition, sensory functions and sensory integration that are crucial for postural control are also compromised. This study intended to examine how patients with schizophrenia coordinate multiple sensory systems to maintain postural stability in dynamic sensory conditions. Twenty-nine patients with schizophrenia and 32 control subjects were recruited. Postural stability of the participants was examined in six sensory conditions of different level of congruency of multiple sensory information, which was based on combinations of correct, removed, or conflicting sensory inputs from visual, somatosensory, and vestibular systems. The excursion of the center of pressure was measured by posturography. Equilibrium scores were derived to indicate the range of anterior-posterior (AP postural sway, and sensory ratios were calculated to explore ability to use sensory information to maintain balance. The overall AP postural sway was significantly larger for patients with schizophrenia compared to the controls [patients (69.62±8.99; controls (76.53±7.47; t1,59 = -3.28, p<0.001]. The results of mixed-model ANOVAs showed a significant interaction between the group and sensory conditions [F5,295 = 5.55, p<0.001]. Further analysis indicated that AP postural sway was significantly larger for patients compared to the controls in conditions containing unreliable somatosensory information either with visual deprivation or with conflicting visual information. Sensory ratios were not significantly different between groups, although small and non-significant difference in inefficiency to utilize vestibular information was also noted. No significant correlations were found between postural stability and clinical characteristics. To sum up, patients with schizophrenia showed increased postural sway and a higher rate of falls during challenging sensory

Success factors of energy performance contracting (EPC) for sustainable building energy efficiency retrofit (BEER) of hotel buildings in China

International Nuclear Information System (INIS)

Xu Pengpeng; Chan, Edwin Hon-Wan; Queena Kun Qian

2011-01-01

Hotel building is a type of high-energy-consuming building and most existing hotel buildings need energy efficiency improvement in China. Energy performance contracting (EPC) is considered a win-win mechanism to organize building energy efficiency retrofit (BEER) project. However, EPC mechanism has been introduced into China relatively recently and many EPCs have not been successful in building energy efficiency retrofit projects. This research aims to develop a set of critical success factors (CSFs) of EPC for sustainable energy efficiency retrofit (BEER) of hotel buildings in China. Semi-structured interviews and a questionnaire survey with practitioners and other professionals were conducted. The findings reveal the relative importance of the 21 number of identified success factors. In order to explore the underlying relationship among the identified critical success factors (CSFs), factor analysis method was adopted for further investigation, which leads to grouping the 21 identified CSFs into six clusters. These are (1) project organization process, (2) EPC project financing for hotel retrofit, (3) knowledge and innovation of EPC, sustainable development (SD), and M and V, (4) implementation of sustainable development strategy, (5) contractual arrangement, and (6) external economic environment. Finally, several relevant policies were proposed to implement EPC successfully in sustainable BEER in hotel buildings. - Highlights: → EPC is a win-win mechanism to organize building energy efficiency retrofit project. → CSFs of EPC mechanism for sustainable BEER of hotel building in China are examined. → Six clusters are extracted from 21 identified CSFs based on factor analysis.

Postural instability detection: aging and the complexity of spatial-temporal distributional patterns for virtually contacting the stability boundary in human stance.

Directory of Open Access Journals (Sweden)

Melissa C Kilby

Full Text Available Falls among the older population can severely restrict their functional mobility and even cause death. Therefore, it is crucial to understand the mechanisms and conditions that cause falls, for which it is important to develop a predictive model of falls. One critical quantity for postural instability detection and prediction is the instantaneous stability of quiet upright stance based on motion data. However, well-established measures in the field of motor control that quantify overall postural stability using center-of-pressure (COP or center-of-mass (COM fluctuations are inadequate predictors of instantaneous stability. For this reason, 2D COP/COM virtual-time-to-contact (VTC is investigated to detect the postural stability deficits of healthy older people compared to young adults. VTC predicts the temporal safety margin to the functional stability boundary ( =  limits of the region of feasible COP or COM displacement and, therefore, provides an index of the risk of losing postural stability. The spatial directions with increased instability were also determined using quantities of VTC that have not previously been considered. Further, Lempel-Ziv-Complexity (LZC, a measure suitable for on-line monitoring of stability/instability, was applied to explore the temporal structure or complexity of VTC and the predictability of future postural instability based on previous behavior. These features were examined as a function of age, vision and different load weighting on the legs. The primary findings showed that for old adults the stability boundary was contracted and VTC reduced. Furthermore, the complexity decreased with aging and the direction with highest postural instability also changed in aging compared to the young adults. The findings reveal the sensitivity of the time dependent properties of 2D VTC to the detection of postural instability in aging, availability of visual information and postural stance and potential applicability as a

Cinerama sickness and postural instability.

Science.gov (United States)

Bos, Jelte E; Ledegang, Wietse D; Lubeck, Astrid J A; Stins, John F

2013-01-01

Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly larger right after the movie than before, and in a lesser extent still so after 45 min. The average standard deviation of the lateral centre of pressure excursions was significantly larger only right afterwards. When low-pass filtered at 0.1 Hz, lateral and for-aft excursions were both significantly larger right after the movie, while for-aft excursions then remained larger even after 45 min. Speculating on previous findings, we predict more sickness and postural instability in 3D than in 2D movies, also suggesting a possible, but yet unknown risk for work-related activities and vehicle operation. Watching motion pictures may be sickening and posturally destabilising, but effects in a cinema are unknown. We, therefore, carried out an observational study showing that sickness then is mainly an issue during the exposure while postural instability is an issue afterwards.

Exercise-induced muscle fatigue in the unaffected knee joint and its influence on postural control and lower limb kinematics in stroke patients

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Sun Wook Park

2017-01-01

Full Text Available This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants (20 stroke patients, 20 age-matched healthy participants were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exercise machine using the pneumatic resistance. We measured static and dynamic balance and lower-limb kinematics during gait. Changes in postural control parameters anteroposterior sway speed and total center of pressure distance differed significantly between the stroke and control groups. In addition, changes in gait kinematic parameters knee and ankle angles of initial contact differed significantly between stroke (paretic and non-paretic and control groups. Muscle fatigue in the unaffected knee and ankle impaired postural control and debilitates kinematic movement of ipsilateral and contralateral lower limbs, and may place the fatigued stroke patients at greater risk for falls.

Increased alertness, better than posture prioritization, explains dual-task performance in prosthesis users and controls under increasing postural and cognitive challenge.

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Howard, Charla L; Perry, Bonnie; Chow, John W; Wallace, Chris; Stokic, Dobrivoje S

2017-11-01

Sensorimotor impairments after limb amputation impose a threat to stability. Commonly described strategies for maintaining stability are the posture first strategy (prioritization of balance) and posture second strategy (prioritization of concurrent tasks). The existence of these strategies was examined in 13 below-knee prosthesis users and 15 controls during dual-task standing under increasing postural and cognitive challenge by evaluating path length, 95% sway area, and anterior-posterior and medial-lateral amplitudes of the center of pressure. The subjects stood on two force platforms under usual (hard surface/eyes open) and difficult (soft surface/eyes closed) conditions, first alone and while performing a cognitive task without and then with instruction on cognitive prioritization. During standing alone, sway was not significantly different between groups. After adding the cognitive task without prioritization instruction, prosthesis users increased sway more under the dual-task than single-task standing (p ≤ 0.028) during both usual and difficult conditions, favoring the posture second strategy. Controls, however, reduced dual-task sway under a greater postural challenge (p ≤ 0.017), suggesting the posture first strategy. With prioritization of the cognitive task, sway was unchanged or reduced in prosthesis users, suggesting departure from the posture second strategy, whereas controls maintained the posture first strategy. Individual analysis of dual tasking revealed that greater postural demand in controls and greater cognitive challenge in prosthesis users led to both reduced sway and improved cognitive performance, suggesting cognitive-motor facilitation. Thus, activation of additional resources through increased alertness, rather than posture prioritization, may explain dual-task performance in both prosthesis users and controls under increasing postural and cognitive challenge.

Postural adjustments are modulated by manual task complexity

Directory of Open Access Journals (Sweden)

Luis Augusto Teixeira

2009-09-01

Full Text Available Daily life activities of humans are characterized by dual tasks, in which a manual task is performed concomitantly with a postural task. Based on the assumption that both manual and postural tasks require attentional resources, no consensus exists as to how the central nervous system modulates postural adjustments in dual tasks. The aim of the present study was to analyze the effect of a manual task requiring attentional resources on shoulder and ankle adjustments as a function of the direction and predictability of postural perturbation. The participants (n=6 were evaluated during the performance of a simple and a complex manual task, while the base of support was moved backward or forward. Latency of activation of the tibialis anterior and gastroc-nemius muscles and angular acceleration of the shoulder were analyzed. The results showed that execution of the complex manual task delayed postural adjustment. Moreover, this delay occurred differently depending on the direction of postural perturbation. The delay in postural adjustment occurred proximally in the case of anterior displacement of the platform, and distally in the case of posterior displacement. Postural adjustments were more affected by the attentional task than by the predictability of platform displacement. These results are consistent with the concept of an integrated control between manual actions and the maintenance of static posture.

The effects of brief swaying on postural control.

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Pagé, Sara; Maheu, Maxime; Landry, Simon P; Champoux, François

2017-12-06

Postural control can be improved with balance training. However, the nature and duration of the training required to enhance posture remains unclear. We studied the effects of 5 min of a self-initiated balance exercise along a single axis on postural control in healthy individuals. Postural control was measured before and after a 5-min period where members of the experimental group were asked to lean their entire body forward and backward and members of the control group were asked to remain seated. A significant improvement for sway velocity, a postural control variable significantly associated with an increased risk of falls, was found in the experimental group following the body sway exercise. These data suggest that a basic exercise can rapidly improve postural control and reduce the risk of falls.

Activation timing of postural muscles of lower legs and prediction of postural disturbance during bilateral arm flexion in older adults.

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Yaguchi, Chie; Fujiwara, Katsuo; Kiyota, Naoe

2017-12-22

Activation timings of postural muscles of lower legs and prediction of postural disturbance were investigated in young and older adults during bilateral arm flexion in a self-timing task and an oddball task with different probabilities of target presentation. Arm flexion was started from a standing posture with hands suspended 10 cm below the horizontal level in front of the body, in which postural control focused on the ankles is important. Fourteen young and 14 older adults raised the arms in response to the target sound signal. Three task conditions were used: 15 and 45% probabilities of the target in the oddball task and self-timing. Analysis items were activation timing of postural muscles (erector spinae, biceps femoris, and gastrocnemius) with respect to the anterior deltoid (AD), and latency and amplitude of the P300 component of event-related brain potential. For young adults, all postural muscles were activated significantly earlier than AD under each condition, and time of preceding gastrocnemius activation was significantly longer in the order of the self-timing, 45 and 15% conditions. P300 latency was significantly shorter, and P300 amplitude was significantly smaller under the 45% condition than under the 15% condition. For older adults, although all postural muscles, including gastrocnemius, were activated significantly earlier than AD in the self-timing condition, only activation timing of gastrocnemius was not significantly earlier than that of AD in oddball tasks, regardless of target probability. No significant differences were found between 15 and 45% conditions in onset times of all postural muscles, and latency and amplitude of P300. These results suggest that during arm movement, young adults can achieve sufficient postural preparation in proportion to the probability of target presentation in the oddball task. Older adults can achieve postural control using ankle joints in the self-timing task. However, in the oddball task, older adults

Neuromechanical tuning of nonlinear postural control dynamics

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Ting, Lena H.; van Antwerp, Keith W.; Scrivens, Jevin E.; McKay, J. Lucas; Welch, Torrence D. J.; Bingham, Jeffrey T.; DeWeerth, Stephen P.

2009-06-01

Postural control may be an ideal physiological motor task for elucidating general questions about the organization, diversity, flexibility, and variability of biological motor behaviors using nonlinear dynamical analysis techniques. Rather than presenting "problems" to the nervous system, the redundancy of biological systems and variability in their behaviors may actually be exploited to allow for the flexible achievement of multiple and concurrent task-level goals associated with movement. Such variability may reflect the constant "tuning" of neuromechanical elements and their interactions for movement control. The problem faced by researchers is that there is no one-to-one mapping between the task goal and the coordination of the underlying elements. We review recent and ongoing research in postural control with the goal of identifying common mechanisms underlying variability in postural control, coordination of multiple postural strategies, and transitions between them. We present a delayed-feedback model used to characterize the variability observed in muscle coordination patterns during postural responses to perturbation. We emphasize the significance of delays in physiological postural systems, requiring the modulation and coordination of both the instantaneous, "passive" response to perturbations as well as the delayed, "active" responses to perturbations. The challenge for future research lies in understanding the mechanisms and principles underlying neuromechanical tuning of and transitions between the diversity of postural behaviors. Here we describe some of our recent and ongoing studies aimed at understanding variability in postural control using physical robotic systems, human experiments, dimensional analysis, and computational models that could be enhanced from a nonlinear dynamics approach.

Obesity impact on the attentional cost for controlling posture.

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Jean-Baptiste Mignardot

2010-12-01

Full Text Available This study investigated the effects of obesity on attentional resources allocated to postural control in seating and unipedal standing.Ten non obese adults (BMI = 22.4±1.3, age = 42.4±15.1 and 10 obese adult patients (BMI = 35.2±2.8, age = 46.2±19.6 maintained postural stability on a force platform in two postural tasks (seated and unipedal. The two postural tasks were performed (1 alone and (2 in a dual-task paradigm in combination with an auditory reaction time task (RT. Performing the RT task together with the postural one was supposed to require some attentional resources that allowed estimating the attentional cost of postural control. 4 trials were performed in each condition for a total of 16 trials.(1 Whereas seated non obese and obese patients exhibited similar centre of foot pressure oscillations (CoP, in the unipedal stance only obese patients strongly increased their CoP sway in comparison to controls. (2 Whatever the postural task, the additional RT task did not affect postural stability. (3 Seated, RT did not differ between the two groups. (4 RT strongly increased between the two postural conditions in the obese patients only, suggesting that body schema and the use of internal models was altered with obesity.Obese patients needed more attentional resources to control postural stability during unipedal stance than non obese participants. This was not the case in a more simple posture such as seating. To reduce the risk of fall as indicated by the critical values of CoP displacement, obese patients must dedicate a strong large part of their attentional resources to postural control, to the detriment of non-postural events. Obese patients were not able to easily perform multitasking as healthy adults do, reflecting weakened psycho-motor abilities.

Obesity Impact on the Attentional Cost for Controlling Posture

Science.gov (United States)

Mignardot, Jean-Baptiste; Olivier, Isabelle; Promayon, Emmanuel; Nougier, Vincent

2010-01-01

Background This study investigated the effects of obesity on attentional resources allocated to postural control in seating and unipedal standing. Methods Ten non obese adults (BMI = 22.4±1.3, age = 42.4±15.1) and 10 obese adult patients (BMI = 35.2±2.8, age = 46.2±19.6) maintained postural stability on a force platform in two postural tasks (seated and unipedal). The two postural tasks were performed (1) alone and (2) in a dual-task paradigm in combination with an auditory reaction time task (RT). Performing the RT task together with the postural one was supposed to require some attentional resources that allowed estimating the attentional cost of postural control. 4 trials were performed in each condition for a total of 16 trials. Findings (1) Whereas seated non obese and obese patients exhibited similar centre of foot pressure oscillations (CoP), in the unipedal stance only obese patients strongly increased their CoP sway in comparison to controls. (2) Whatever the postural task, the additional RT task did not affect postural stability. (3) Seated, RT did not differ between the two groups. (4) RT strongly increased between the two postural conditions in the obese patients only, suggesting that body schema and the use of internal models was altered with obesity. Interpretation Obese patients needed more attentional resources to control postural stability during unipedal stance than non obese participants. This was not the case in a more simple posture such as seating. To reduce the risk of fall as indicated by the critical values of CoP displacement, obese patients must dedicate a strong large part of their attentional resources to postural control, to the detriment of non-postural events. Obese patients were not able to easily perform multitasking as healthy adults do, reflecting weakened psycho-motor abilities. PMID:21187914

Dual task interference on postural sway, postural transitions and gait in people with Parkinson's disease and freezing of gait.

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de Souza Fortaleza, Ana Claudia; Mancini, Martina; Carlson-Kuhta, Patty; King, Laurie A; Nutt, John G; Chagas, Eliane Ferrari; Freitas, Ismael Forte; Horak, Fay B

2017-07-01

Freezing of gait (FoG) is associated with less automatic gait and more impaired cognition, balance and postural transitions compared to people with PD who do not have FoG. However, it is unknown whether dual-task cost during postural sway, postural transitions (such as gait initiation and turning), and gait are more in subjects with Parkinson's disease (PD) who have freezing of gait (FoG+) compared to those who do not have FoG (FoG-). Here, we hypothesized that the effects of a cognitive dual task on postural sway, postural transitions and gait would be larger in FoG+ than FoG-. Thirty FoG- and 24 FoG+ performed an Instrumented Stand and Walk test in OFF medication state, with and without a secondary cognitive task (serial subtraction by 3s). Measures of postural sway, gait initiation, turning, and walking were extracted using body-worn inertial sensors. FoG+ showed significantly larger dual task cost than FoG- for several gait metrics, but not during postural sway or postural transitions. During walking, FoG+ exhibited a larger dual task cost than FoG- resulting in shorter stride length and slower stride velocity. During standing, FoG+ showed a larger postural sway compared to FoG- and during gait initiation, FoG+, but not FoG-, showed a longer first step duration during the dual-task condition compared to single-task condition (interaction effect, p=0.04). During turning, both groups showed a slower turn peak speed in the dual-task condition compared to single task condition. These findings partly support our hypothesis that dual task cost on walking is greater in FoG+ than FoG-. Copyright © 2017. Published by Elsevier B.V.

Maintenance contract strategies for reliability at minimum cost

International Nuclear Information System (INIS)

Gamman, E.

1992-01-01

The conference paper deals with offshore contract philosophies concerning maintenance. The main philosophies of the contract should be built on the following key success factors: Safe operations and correct quality must be sustained at any time; the maintenance contractor should be viewed as a cooperation partner, not only as a supplier; optimum exploitation of learning curve effects and economies of scale. The paper illustrates the importance of each of them in a contract context with a few recommendations

A flexed posture in elderly patients is associated with impairments in postural control during walking.

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de Groot, Maartje H; van der Jagt-Willems, Hanna C; van Campen, Jos P C M; Lems, Willem F; Beijnen, Jos H; Lamoth, Claudine J C

2014-02-01

A flexed posture (FP) is characterized by protrusion of the head and an increased thoracic kyphosis (TK), which may be caused by osteoporotic vertebral fractures (VFs). These impairments may affect motor function, and consequently increase the risk of falling and fractures. The aim of the current study was therefore to examine postural control during walking in elderly patients with FP, and to investigate the relationship with geriatric phenomena that may cause FP, such as increased TK, VFs, frailty, polypharmacy and cognitive impairments. Fifty-six elderly patients (aged 80 ± 5.2 years; 70% female) walked 160 m at self-selected speed while trunk accelerations were recorded. Walking speed, mean stride time and coefficient of variation (CV) of stride time were recorded. In addition, postural control during walking was quantified by time-dependent variability measures derived from the theory of stochastic dynamics, indicating smoothness, degree of predictability, and local stability of trunk acceleration patterns. Twenty-five patients (45%) had FP and demonstrated a more variable and less structured gait pattern, and a more irregular trunk acceleration pattern than patients with normal posture. FP was significantly associated with an increased TK, but not with other geriatric phenomena. An increased TK may bring the body's centre of mass forward, which requires correcting responses, and reduces the ability to respond on perturbation, which was reflected by higher variation in the gait pattern in FP-patients. Impairments in postural control during walking are a major risk factor for falling: the results indicate that patients with FP have impaired postural control during walking and might therefore be at increased risk of falling. Copyright © 2013 Elsevier B.V. All rights reserved.

The dentist’s operating posture – ergonomic aspects

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Pîrvu, C; Pătraşcu, I; Pîrvu, D; Ionescu, C

2014-01-01

Abstract The practice of dentistry involves laborious high finesse dental preparations, precision and control in executions that require a particular attention, concentration and patience of the dentist and finally the dentist’s physical and mental resistance. The optimal therapeutic approach and the success of practice involve special working conditions for the dentist and his team in an ergonomic environment. The meaning of the posture in ergonomics is the manner in which different parts of the body are located and thus the reports are established between them in order to allow a special task execution. This article discusses the posture adopted by dentists when they work, beginning with the balanced posture and going to different variants of posture. The ideal posture of a dentist gives him, on the one hand the optimal working conditions (access, visibility and control in the mouth) and on the other hand, physical and psychological comfort throughout the execution of the clinical acts. Although the theme of dentist posture is treated with great care and often presented in the undergraduate courses and the continuing education courses on ergonomics in dentistry, many dentists do not know the subject well enough nor the theoretical issues and therefore nor the practical applicability. The risk and perspective of the musculoskeletal disorders related to unbalanced postures should determine the dentists take postural corrective actions and compensation measures in order to limit the negative effects of working in a bad posture. PMID:25184007

USE OF SOFTWARES FOR POSTURE ASSESSMENT: INTEGRATIVE REVIEW

Directory of Open Access Journals (Sweden)

Edyla Maria Porto de Freitas Camelo

2015-09-01

Full Text Available To carry out an integrative literature review on the postural analysis softwares available today. It is an integrative-narrative review of qualitative and methodological nature performed during April-July 2014. As inclusion criteria, the articles should be bibliographical or original research and available with full access. At first, we proceeded to the identification of the keywords for the softwares related to postural assessment commonly used in the health field, in such case "posture", "software", and "postural assessment". The search was narrowed by publication date from 2002 to 2014. Through the information acquired from the articles and from the software developers, information on 12 programs that assist the postural evaluation were obtained - Alcimage, All Body Scan 3D, Aplob, APPID, Biotonix, Corporis Pro, Fisimetrix, Fisiometer Posturograma, Physical Fisio, Physio Easy, Posture Print and SAPO. However, only one tool has more information and studies, namely SAPO. There are many postural analysis softwares available on the internet today, however, these are quite disparate in relation to possible answers and are still poorly widespread as research tools.

Effects of rapid maxillary expansion on head posture, postural stability, and fall risk

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Fatih Celebi

2017-01-01

Full Text Available Objective: The aim of this study was to investigate the effects of rapid maxillary expansion (RME on head posture, postural stability, and fall risk. Materials and Methods: A sample of 51 adolescent patients was randomly divided into two groups. In the first group, which consisted of 28 patients (15 females and 13 males, RME was performed as a part of routine orthodontic treatment. The remaining 23 individuals (12 females and 11 males served as the control group. Lateral cephalometric radiographs taken in natural head position, postural stability, and fall risk scores were obtained during the first visit. They were repeated on average 3.8 months and 3.5 months later for the study and control groups, respectively. The changes were analyzed using the Wilcoxon signed-rank test, paired samples t-test, Mann–Whitney U-test, and independent samples t-test. Results: As a result of RME, a statistically significant decrease was detected in the fall risk score (P < 0.05 in the study group, while the head position and postural stability remained unchanged. For the control group, no significant changes were observed in all measurements. Conclusions: The result of the present study suggests that RME has a capacity of improving fall risk.

Assessing Somatosensory Utilization during Unipedal Postural Control.

Science.gov (United States)

Goel, Rahul; De Dios, Yiri E; Gadd, Nichole E; Caldwell, Erin E; Peters, Brian T; Reschke, Millard F; Bloomberg, Jacob J; Oddsson, Lars I E; Mulavara, Ajitkumar P

2017-01-01

Multisensory-visual, vestibular and somatosensory information is integrated for appropriate postural control. The primary goal of this study was to assess somatosensory utilization during a functional motor task of unipedal postural control, in normal healthy adults. Assessing individual bias in the utilization of individual sensory contributions during postural control may help customization of rehabilitation protocols. In this study, a test paradigm of unipedal stance control in supine orientation with and without vision was assessed. Postural control in this test paradigm was hypothesized to utilize predominantly contributions of somatosensory information from the feet and ankle joint, with minimal vestibular input. Fourteen healthy subjects "stood" supine on their dominant leg while strapped to a backpack frame that was freely moving on air-bearings, to remove available otolith tilt cues with respect to gravity that influences postural control when standing upright. The backpack was attached through a cable to a pneumatic cylinder that provided a gravity-like load. Subjects performed three trials each with Eyes-open (EO) and Eyes-closed (EC) while loaded with 60% body weight. There was no difference in unipedal stance time (UST) across the two conditions with EC condition challenging the postural control system greater than the EO condition. Stabilogram-diffusion analysis (SDA) indicated that the critical mean square displacement was significantly different between the two conditions. Vestibular cues, both in terms of magnitude and the duration for which relevant information was available for postural control in this test paradigm, were minimized. These results support our hypothesis that maintaining unipedal stance in supine orientation without vision, minimizes vestibular contribution and thus predominantly utilizes somatosensory information for postural control.

[Head posture in orthodontics: physiopathology and clinical aspects 2].

Science.gov (United States)

Caltabiano, M; Verzi, P; Scire Scappuzzo, G

1989-01-01

The Authors review in orthodontic respects present knowledges about head posture involvement in craniofacial morphogenesis and pathology. Relationships between craniofacial morphology, craniocervical posture, craniomandibular posture, cervical spine curvature, hyoid bone position and posture of whole body in space are shown, in attempt to explain conditions such as "forward head posture", mouth breathing and some occlusal disorders. Main methods to evaluate craniocervical relations on lateral skull radiographs are analysed. Pathogenesis of pain syndromes associated with abnormal craniocervical and craniomandibular mechanics are also briefly treated.

Relationship between craniomandibular disorders and poor posture.

Science.gov (United States)

Nicolakis, P; Nicolakis, M; Piehslinger, E; Ebenbichler, G; Vachuda, M; Kirtley, C; Fialka-Moser, V

2000-04-01

The purpose of this research was to show that a relationship between craniomandibular disorders (CMD) and postural abnormalities has been repeatedly postulated, but still remains unproven. This study was intended to test this hypothesis. Twenty-five CMD patients (mean age 28.2 years) were compared with 25 gender and age matched controls (mean age 28.3 years) in a controlled, investigator-blinded trial. Twelve postural and ten muscle function parameters were examined. Measurements were separated into three subgroups, consisting of those variables associated with the cervical region, the trunk in the frontal plane, and the trunk in the sagittal plane. Within these subgroups, there was significantly more dysfunction in the patients, compared to control subjects (Mann-Whitney U test p Postural and muscle function abnormalities appeared to be more common in the CMD group. Since there is evidence of the mutual influence of posture and the craniomandibular system, control of body posture in CMD patients is recommended, especially if they do not respond to splint therapy. Whether poor posture is the reason or the result of CMD cannot be distinguished by the data presented here.

The reliability and validity of the Saliba Postural Classification System.

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Collins, Cristiana Kahl; Johnson, Vicky Saliba; Godwin, Ellen M; Pappas, Evangelos

2016-07-01

To determine the reliability and validity of the Saliba Postural Classification System (SPCS). Two physical therapists classified pictures of 100 volunteer participants standing in their habitual posture for inter and intra-tester reliability. For validity, 54 participants stood on a force plate in a habitual and a corrected posture, while a vertical force was applied through the shoulders until the clinician felt a postural give. Data were extracted at the time the give was felt and at a time in the corrected posture that matched the peak vertical ground reaction force (VGRF) in the habitual posture. Inter-tester reliability demonstrated 75% agreement with a Kappa = 0.64 (95% CI = 0.524-0.756, SE = 0.059). Intra-tester reliability demonstrated 87% agreement with a Kappa = 0.8, (95% CI = 0.702-0.898, SE = 0.05) and 80% agreement with a Kappa = 0.706, (95% CI = 0.594-0818, SE = 0.057). The examiner applied a significantly higher (p < 0.001) peak vertical force in the corrected posture prior to a postural give when compared to the habitual posture. Within the corrected posture, the %VGRF was higher when the test was ongoing vs. when a postural give was felt (p < 0.001). The %VGRF was not different between the two postures when comparing the peaks (p = 0.214). The SPCS has substantial agreement for inter- and intra-tester reliability and is largely a valid postural classification system as determined by the larger vertical forces in the corrected postures. Further studies on the correlation between the SPCS and diagnostic classifications are indicated.

Sustainability clauses in international supply chain contracts

DEFF Research Database (Denmark)

Peterkova, Katerina

2014-01-01

Our current society is not successful in mitigation of global social and environmental challenges. States lack legal tools, and sometimes also the will, to secure social and environmental interests transnationally and the existing soft and private regulation is criticized for its weak legitimacy...... but also to do business exclusively with socially responsible partners. Unawareness, either intentional or negligent, of unethical behaviour within a company’s supply chain may lead to an assumption that the company is complicit in such a conduct. The paper discusses a hypothesis that sustainability...... contractual clauses (SCCs) in international supply chain agreements may help to overcome the regulatory gap in relation to global sustainability while concurrently protect companies against potential social, economic and legal risks threatening in connection to unethical behaviour of their suppliers. As parts...

Ergonomic strategies to improve radiographers' posture during mammography activities.

Science.gov (United States)

Cernean, Nicolai; Serranheira, Florentino; Gonçalves, Pedro; Sá Dos Reis, Cláudia

2017-08-01

To identify alternatives for radiographers' postures while performing mammography that can contribute to reduce the risk of work-related musculoskeletal disorders (WRMSDs). Radiographers' postures to positioning craniocaudal (CC) and mediolateral oblique (MLO) views were simulated without any intervention for three scenarios: radiographer/patient with similar statures, radiographer smaller than patient and radiographer taller than patient. Actions were taken to modify the postures: seated radiographer; patient on a step; seated patient; radiographer on a step. All the postures were analysed using kinovea 0.8.15 software and the angles were measured twice and classified according to European standard EN1005-4: 2005. The non-acceptable angles were measured mainly during MLO positioning when radiographer was taller than the patient: 139° and 120° for arm-flexion and abduction, 72° for trunk and -24° for head/neck-flexion. The introduction of alternative postures (radiographer seated), allowed improvements in posture (60° and 99° for arm flexion and abduction, 14° for trunk and 0° for head/neck flexion), being classified as acceptable. The alternative postures simulated have the potential to reduce the risk of developing WRMSDs when radiographers and patients have different statures. • Radiographers' postures in mammography can contribute to work-related musculoskeletal disorders • Non-acceptable posture was identified for MLO breast positioning (radiographer taller than patient) • Adapting posture to patient biotype reduces the WRMSD risk for radiographers.

Postural ortostatisk takykardi-syndrom

DEFF Research Database (Denmark)

Brinth, Louise; Pors, Kirsten; Mehlsen, Jesper

2015-01-01

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous condition of dysautonomia and suspected autoimmunity characterized by abnormal increments in heart rate upon assumption of the upright posture accompanied by symptoms of cerebral hypoperfusion and sympathoexcitation. An increase...... in heart rate equal to or greater than 30 bpm or to levels higher than 120 bpm during a head-up tilt test is the main diagnostic criterion. Management includes both non-pharmacological and pharmacological treatment focusing on stress management, volume expansion and heart rate control....

Assessing Somatosensory Utilization during Unipedal Postural Control

OpenAIRE

Goel, Rahul; De Dios, Yiri E.; Gadd, Nichole E.; Caldwell, Erin E.; Peters, Brian T.; Reschke, Millard F.; Bloomberg, Jacob J.; Oddsson, Lars I. E.; Mulavara, Ajitkumar P.

2017-01-01

Multisensory—visual, vestibular and somatosensory information is integrated for appropriate postural control. The primary goal of this study was to assess somatosensory utilization during a functional motor task of unipedal postural control, in normal healthy adults. Assessing individual bias in the utilization of individual sensory contributions during postural control may help customization of rehabilitation protocols. In this study, a test paradigm of unipedal stance control in supine orie...

Postural Control in Children: Implications for Pediatric Practice

Science.gov (United States)

Westcott, Sarah L.; Burtner, Patricia

2004-01-01

Based on a systems theory of motor control, reactive postural control (RPA) and anticipatory postural control (APA) in children are reviewed from several perspectives in order to develop an evidence-based intervention strategy for improving postural control in children with limitations in motor function. Research on development of postural…

Decrease in back strength in asymmetric trunk postures

NARCIS (Netherlands)

Vink, P.; Daanen, H. A M; Meijst, W. J.; Ligteringen, J.

1992-01-01

The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry

Investigating the Effects of Different Working Postures on Cognitive Performance

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Sharareh Mohammadi

2018-01-01

Conclusion This study demonstrates that cognitive performance is affected by working postures. This study demonstrates that standard sitting posture is the best posture. Therefore, it is recommended that sitting posture can help in increasing cognitive performance in the workplace.

Testing postural control among various osteoporotic patient groups: a literature review.

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de Groot, Maartje H; van der Jagt-Willems, Hanna C; van Campen, Jos P C M; Lems, Willem F; Lamoth, Claudine J C

2012-10-01

Osteoporosis can cause vertebral fractures, which might lead to a flexed posture, impaired postural control and consequently increased fall risk. Therefore, the aim of the present review was to examine whether postural control of patients with osteoporosis, vertebral fractures, thoracic kyphosis and flexed posture is affected. Furthermore, instruments measuring postural control were evaluated and examined for sensitivity and easy clinical use. Until February 2011, electronic databases were systematically searched for cross-sectional studies. Methodological quality was assessed with a modified Downs & Black scale. Of the 518 found studies, 18 studies were included. Postural control was generally affected for patients with vertebral fractures, thoracic kyphosis and flexed posture. Patients with osteoporosis had impaired postural control when assessed with computerized instruments. Easy performance-based tests did not show any impairments. There is evidence for an impaired postural control in all patient groups included. Impaired postural control is an important risk factor for falls. Functional performance tests are not sensitive and specific enough to detect affected postural control in patients with osteoporosis. To detect impaired postural control among osteoporotic patients and to obtain more insight into the underlying mechanisms of postural control, computerized instruments are recommended, such as easy-to-use ambulant motion-sensing (accelerometry) technology. © 2012 Japan Geriatrics Society.

Voluntarily controlled but not merely observed visual feedback affects postural sway

Science.gov (United States)

Asai, Tomohisa; Hiromitsu, Kentaro; Imamizu, Hiroshi

2018-01-01

Online stabilization of human standing posture utilizes multisensory afferences (e.g., vision). Whereas visual feedback of spontaneous postural sway can stabilize postural control especially when observers concentrate on their body and intend to minimize postural sway, the effect of intentional control of visual feedback on postural sway itself remains unclear. This study assessed quiet standing posture in healthy adults voluntarily controlling or merely observing visual feedback. The visual feedback (moving square) had either low or high gain and was either horizontally flipped or not. Participants in the voluntary-control group were instructed to minimize their postural sway while voluntarily controlling visual feedback, whereas those in the observation group were instructed to minimize their postural sway while merely observing visual feedback. As a result, magnified and flipped visual feedback increased postural sway only in the voluntary-control group. Furthermore, regardless of the instructions and feedback manipulations, the experienced sense of control over visual feedback positively correlated with the magnitude of postural sway. We suggest that voluntarily controlled, but not merely observed, visual feedback is incorporated into the feedback control system for posture and begins to affect postural sway. PMID:29682421

Development of low postural tone compensatory patterns in children - theoretical basis.

Science.gov (United States)

Gogola, Anna; Saulicz, Edward; Kuszewski, Michał; Matyja, Małgorzata; Myśliwiec, Andrzej

2014-01-01

Neurological literature indicates the existence of children with low postural tone without association with central nervous system damage. This fact induces to think about mechanisms, which allow these children to maintain upright posture. There is a suspicion that compensatory mechanism included in this process, enables to achieve upright posture, but at expense of body posture quality. Observations of children's developmental stages caused determination of some postural tone area, which comprise both children with normotonia and with low postural tone without characteristics of central nervous system (CNS) damage. Set of specific qualities allows determination of two types of low postural tone: spastoidal and atetoidal type. Spastoidal type is characterized by deep trunk muscles (local) low postural tone compensated by excessive tension of superficial muscles (global). Atetoidal type includes children with low postural tone in both deep and superficial muscles. At inefficient active subsystem, verticalization proceeds at excessive use of passive subsystem qualities, that is meniscus, ligament, bone shape, and muscles passive features. From neurodevelopmental point of view compensatory mechanisms can be used in children with low postural tone in order to achieve upright posture, but at expense of body posture quality.

Anatomy and histochemistry of spread-wing posture in birds. I. Wing drying posture in the double-crested cormorant, Phalacrocorax auritus.

Science.gov (United States)

Meyers, Ron A

1997-07-01

Spread-wing postures of birds often have been studied with respect to the function of behavior, but ignored with regard to the mechanism by which the birds accomplish posture. The double-crested cormorant, Phalacrocorax auritus, was used as a model for this study of spread-wing posture. Those muscles capable of positioning and maintaining the wing in extension and protraction were assayed histochemically for the presence of slow (postural) muscle fibers. Within the forelimb of Phalacrocorax, Mm. coracobrachialis cranialis, pectoralis thoracicus (cranial portion), deltoideus minor, triceps scapularis, and extensor metacarpi radialis pars dorsalis and ventralis were found to contain populations of slow-twitch or slow-tonic muscle fibers. These slow fibers in the above muscles are considered to function during spread-wing posture in this species. J Morphol 233:67-76, 1997. © 1997 Wiley-Liss, Inc. Copyright © 1997 Wiley-Liss, Inc.

Acute effects of muscle fatigue on anticipatory and reactive postural control in older individuals: a systematic review of the evidence.

Science.gov (United States)

Papa, Evan V; Garg, Hina; Dibble, Leland E

2015-01-01

Falls are the leading cause of traumatic brain injury and fractures and the No. 1 cause of emergency department visits by older adults. Although declines in muscle strength and sensory function contribute to increased falls in older adults, skeletal muscle fatigue is often overlooked as an additional contributor to fall risk. In an effort to increase awareness of the detrimental effects of skeletal muscle fatigue on postural control, we sought to systematically review research studies examining this issue. The specific purpose of this review was to provide a detailed assessment of how anticipatory and reactive postural control tasks are influenced by acute muscle fatigue in healthy older individuals. An extensive search was performed using the CINAHL, Scopus, PubMed, SPORTDiscus, and AgeLine databases for the period from inception of each database to June 2013. This systematic review used standardized search criteria and quality assessments via the American Academy for Cerebral Palsy and Developmental Medicine Methodology to Develop Systematic Reviews of Treatment Interventions (2008 version, revision 1.2, AACPDM, Milwaukee, Wisconsin). A total of 334 citations were found. Six studies were selected for inclusion, whereas 328 studies were excluded from the analytical review. The majority of articles (5 of 6) utilized reactive postural control paradigms. All studies incorporated extrinsic measures of muscle fatigue, such as declines in maximal voluntary contraction or available active range of motion. The most common biomechanical postural control task outcomes were spatial measures, temporal measures, and end-points of lower extremity joint kinetics. On the basis of systematic review of relevant literature, it appears that muscle fatigue induces clear deteriorations in reactive postural control. A paucity of high-quality studies examining anticipatory postural control supports the need for further research in this area. These results should serve to heighten

Posture Detection Based on Smart Cushion for Wheelchair Users

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Congcong Ma

2017-03-01

Full Text Available The postures of wheelchair users can reveal their sitting habit, mood, and even predict health risks such as pressure ulcers or lower back pain. Mining the hidden information of the postures can reveal their wellness and general health conditions. In this paper, a cushion-based posture recognition system is used to process pressure sensor signals for the detection of user’s posture in the wheelchair. The proposed posture detection method is composed of three main steps: data level classification for posture detection, backward selection of sensor configuration, and recognition results compared with previous literature. Five supervised classification techniques—Decision Tree (J48, Support Vector Machines (SVM, Multilayer Perceptron (MLP, Naive Bayes, and k-Nearest Neighbor (k-NN—are compared in terms of classification accuracy, precision, recall, and F-measure. Results indicate that the J48 classifier provides the highest accuracy compared to other techniques. The backward selection method was used to determine the best sensor deployment configuration of the wheelchair. Several kinds of pressure sensor deployments are compared and our new method of deployment is shown to better detect postures of the wheelchair users. Performance analysis also took into account the Body Mass Index (BMI, useful for evaluating the robustness of the method across individual physical differences. Results show that our proposed sensor deployment is effective, achieving 99.47% posture recognition accuracy. Our proposed method is very competitive for posture recognition and robust in comparison with other former research. Accurate posture detection represents a fundamental basic block to develop several applications, including fatigue estimation and activity level assessment.

Relationship between Postural Deformities and Frontal Function in Parkinson's Disease

OpenAIRE

Ninomiya, Satoko; Morita, Akihiko; Teramoto, Hiroko; Akimoto, Takayoshi; Shiota, Hiroshi; Kamei, Satoshi

2015-01-01

Postural deformities and executive dysfunction (ED) are common symptoms of Parkinson's disease (PD); however, the relationship between postural deformities and ED in patients with PD remains unclear. This study assessed the relationship between postural deformities and ED in patients with PD. Sixty-five patients with sporadic PD were assessed for the severity of postural deformities and executive function. The severity of postural deformities was scored using the United Parkinson's Disease Ra...

PENINGKATAN STABILITAS POSTURAL PADA LANSIA MELALUI BALANCE EXERCISE

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Kusnanto .

2010-12-01

Full Text Available Stabilitas postural adalah masalah yang umum pada lansia. Balance exercise dapat dijadikan alternative latihan bagi lansia. Latihan ini meliputi 5 gerakan (plantar flexion, hip flexion, hip flexion, knee flexion dan side leg raise. Penelitian ini bertujuan untuk menganalisa efek dari balance exercise terhadap peningkatan stabilitas postural pada lansia. Penelitian ini menggunakan design pre eksperimen. Populasi yang digunakan adalah lansia di Panti Wreda Bangkalan. Total sampel adalah 11 responden, yang diambil berdasarkan kriteria inklusi. Variabel dependen adalah balance exercise dan variabel independen adalah stabilitas postural. Stabilitas postural diukur menggunakan 2 tes, yaitu tes Tinetti dan TUGT (Time Up and Go Test. Data dianalisa menggunakan paired t test dengan level signifikan 0,05. Hasil penelitian menunjukkan bahwa balance exercise secara signifikan dapat meningkatkan stabilitas postural. Pada tes Tinetti (p=0,000 dan di TUGT (p=0,001. Sehingga dapat disimpulkan bahwa terdapat hasil yang signifikan antara balance exercise dengan peningkatan stabilitas postural pada lansia. Hal ini disebabkan Karena balance exercise dapat membuat otot lansia menjadi hipertrofi. Hipertrofi dapat meningkatkan kekuatan otot sehingga stabilitas postural lansia dapat meningkat. Penelitian yang akan datang diharapkan melibatkan lebih banyak responden dengan waktu penelitian yang lebih lama dan pengukuran yang lebih baik untuk memastikan hasil yang lebih akurat.

Clinical evaluation of postural posture of patients with previous stroke subjected to early rehabilitation

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Anna Sagan

2018-02-01

Full Text Available Introduction: Impairment disorders are often found in patients with stroke and impairment of motor and cognitive functions. This is a very serious complication because, by imposing a motor impairment, it aggravates the condition of disability and makes it difficult to conduct physical rehabilitation.The resulting neurological deficits due to stroke determine functional disorders. The possibility of locomotion is usually compromised, therefore the risk of falls increases significantly. The aim of the work is to present Postural Assesment Scale for Strock PASS with the postural stroke assessment scale, the impact of early rehabilitation of patients staying in the neurology ward.Material and methods: Postural examination was carried out among 17 people, of which 8 were women, and 9 were male. The study was divided into two stages. The first stage occurred immediately after the stroke and the second one before the patient was discharged from the ward. Research was carried out at the Biegański Specialist Hospital in Grudziądz in the Department of Neurology and Clinical Neuroimmunology and Impact Department.Conclusions: The results of the postural studies carried out in people with previous stroke subjected to early physiotherapy have a beneficial effect of the conducted therapy. There are positive changes between the first and the final examination of the patients.

Invisible Motivation of Online Adult Learners During Contract Learning

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Seung Youn (Yonnie Chyung, Ed.D.

2007-07-01

Full Text Available In a face-to-face classroom, the instructor can easily diagnose students’ motivational status by observing their facial expressions and postures, but such cues are absent in an online classroom. Therefore, online instructors often estimate students’ motivational level based on their online behavior such as the number of messages they post, and look for effective strategies to help them actively participate in online dialogues. One such strategy is contract learning which facilitates self-directed behaviors through structuring an agreed learning process. This study reports a contract learning strategy in a graduate-level online class, examining whether a sample of 28 students’ motivation could indeed be predicted by their online behavior. Results from the study found that the students’ online behavior was not a predictor for their motivational status, though there were age and gender differences in their online behavior. The students felt more self-directed and motivated during contract learning, but what they really liked was being able to select assignments that were relevant to their interests and needs. This paper concludes by discussing practical implications of the findings at the end.

INFLUENCE FACTORS FOR LEASING MARKET CONTRACTS

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Oana BĂRBULESCU

2016-11-01

Full Text Available This paper aims to investigate the relationship between leasing contracts and some factors that influence the value of these contracts. In order to do this, we have decided on some quantitative marketing research by appealing to statistics for accomplishing the objectives that we have set: to find a correlation between the turnover percentage assigned to leasing expenses and several influence factors. This study indicated that the more contracts are signed by a firm, the more likely is to assign a bigger fraction of the income to each new leasing contract. The study confirmed that bigger companies are relying more on leasing as a way of financing than small companies. This study also discovered that companies with more employees are using larger contracts in order to sustain their activity. The findings are expected to contribute to adjusting the offers by the leasing companies, taking into consideration these factors and to using these factors in order to better predict the market evolution.

Postural balance in low back pain patients

DEFF Research Database (Denmark)

Maribo, Thomas; Schiøttz-Christensen, Berit; Jensen, Lone Donbæk

2012-01-01

INTRODUCTION: Altered postural control has been observed in low back pain (LBP) patients. They seem to be more dependent on vision when standing. The objective of the study was to determine concurrent and predictive validity of measures of postural stability in LBP patients. MATERIALS AND METHODS......: Centre of Pressure (CoP) measurements were tested against pain, fear of pain, and physical function. Velocity, anterior-posterior displacement, and the Romberg Ratio obtained on a portable force platform were used as measures of postural stability. RESULTS: Baseline and 12-week follow-up results of 97....... CONCLUSION: This first study of concurrent and predictive validity of postural balance in LBP patients revealed no association between CoP measures and pain, fear of pain, and physical function....

Relationship between Postural Deformities and Frontal Function in Parkinson’s Disease

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Satoko Ninomiya

2015-01-01

Full Text Available Postural deformities and executive dysfunction (ED are common symptoms of Parkinson’s disease (PD; however, the relationship between postural deformities and ED in patients with PD remains unclear. This study assessed the relationship between postural deformities and ED in patients with PD. Sixty-five patients with sporadic PD were assessed for the severity of postural deformities and executive function. The severity of postural deformities was scored using the United Parkinson’s Disease Rating Scale item 28 score: no postural deformity (0, mild postural deformities (1, or severe postural deformities (2–4. Executive function was assessed using the Behavioral Assessment of the Dysexecutive Syndrome (BADS and an age-controlled standardized BADS score <70 was defined as ED. Age-controlled standardized BADS scores were compared across the three groups using the Kruskal-Wallis test. Relationship between ED and the severity of postural deformities was assessed using the Mann-Whitney U test. Age-controlled standardized BADS score significantly differed among the three groups P=0.005. ED was significantly related to the severity of postural deformities P=0.0005. The severity of postural deformities was associated with a lower age-controlled standardized BADS score and ED, and these findings suggest that postural deformities were associated with frontal dysfunction in patients with PD.

Central common drive to antagonistic ankle muscles in relation to short-term co-contraction training in non-dancers and professional ballet dancers

DEFF Research Database (Denmark)

Geertsen, Svend Sparre; Kjær, Majken; Pedersen, Kasper Karhu

2013-01-01

Optimization of co-contraction of antagonistic muscles around the ankle joint has been shown to involve plastic changes in spinal and cortical neural circuitries. Such changes may explain the ability of elite ballet dancers to maintain a steady balance during various ballet postures. Here we inve...

Inactivity periods and postural change speed can explain atypical postural change patterns of Caenorhabditis elegans mutants.

Science.gov (United States)

Fukunaga, Tsukasa; Iwasaki, Wataru

2017-01-19

With rapid advances in genome sequencing and editing technologies, systematic and quantitative analysis of animal behavior is expected to be another key to facilitating data-driven behavioral genetics. The nematode Caenorhabditis elegans is a model organism in this field. Several video-tracking systems are available for automatically recording behavioral data for the nematode, but computational methods for analyzing these data are still under development. In this study, we applied the Gaussian mixture model-based binning method to time-series postural data for 322 C. elegans strains. We revealed that the occurrence patterns of the postural states and the transition patterns among these states have a relationship as expected, and such a relationship must be taken into account to identify strains with atypical behaviors that are different from those of wild type. Based on this observation, we identified several strains that exhibit atypical transition patterns that cannot be fully explained by their occurrence patterns of postural states. Surprisingly, we found that two simple factors-overall acceleration of postural movement and elimination of inactivity periods-explained the behavioral characteristics of strains with very atypical transition patterns; therefore, computational analysis of animal behavior must be accompanied by evaluation of the effects of these simple factors. Finally, we found that the npr-1 and npr-3 mutants have similar behavioral patterns that were not predictable by sequence homology, proving that our data-driven approach can reveal the functions of genes that have not yet been characterized. We propose that elimination of inactivity periods and overall acceleration of postural change speed can explain behavioral phenotypes of strains with very atypical postural transition patterns. Our methods and results constitute guidelines for effectively finding strains that show "truly" interesting behaviors and systematically uncovering novel gene

ADIABATIC HEATING OF CONTRACTING TURBULENT FLUIDS

International Nuclear Information System (INIS)

Robertson, Brant; Goldreich, Peter

2012-01-01

Turbulence influences the behavior of many astrophysical systems, frequently by providing non-thermal pressure support through random bulk motions. Although turbulence is commonly studied in systems with constant volume and mean density, turbulent astrophysical gases often expand or contract under the influence of pressure or gravity. Here, we examine the behavior of turbulence in contracting volumes using idealized models of compressed gases. Employing numerical simulations and an analytical model, we identify a simple mechanism by which the turbulent motions of contracting gases 'adiabatically heat', experiencing an increase in their random bulk velocities until the largest eddies in the gas circulate over a Hubble time of the contraction. Adiabatic heating provides a mechanism for sustaining turbulence in gases where no large-scale driving exists. We describe this mechanism in detail and discuss some potential applications to turbulence in astrophysical settings.

Variation between seated and standing/walking postures among male and female call centre operators

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Toomingas Allan

2012-03-01

Full Text Available Abstract Background The dose and time-pattern of sitting has been suggested in public health research to be an important determinant of risk for developing a number of diseases, including cardiovascular disorders and diabetes. The aim of the present study was to assess the time-pattern of seated and standing/walking postures amongst male and female call centre operators, on the basis of whole-shift posture recordings, analysed and described by a number of novel variables describing posture variation. Methods Seated vs. standing/walking was recorded using dichotomous inclinometers throughout an entire work shift for 43 male and 97 female call centre operators at 16 call centres. Data were analysed using an extensive set of variables describing occurrence of and switches between seated and standing/walking, posture similarity across the day, and compliance with standard recommendations for computer work. Results The majority of the operators, both male and female, spent more than 80% of the shift in a seated posture with an average of 10.4 switches/hour between seated and standing/walking or vice versa. Females spent, on average, 11% of the day in periods of sustained sitting longer than 1 hour; males 4.6% (p = 0.013. Only 38% and 11% of the operators complied with standard recommendations of getting an uninterrupted break from seated posture of at least 5 or 10 minutes, respectively, within each hour of work. Two thirds of all investigated variables showed coefficients of variation between subjects above 0.5. Since work tasks and contractual break schedules were observed to be essentially similar across operators and across days, this indicates that sedentary behaviours differed substantially between individuals. Conclusions The extensive occurrence of uninterrupted seated work indicates that efforts should be made at call centres - and probably in other settings in the office sector - to introduce more physical variation in terms of standing

Compromising Postural Balance in the Elderly

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Swanenburg, Jaap; de Bruin, Eling D.; Uebelhart, Daniel; Mulder, Theo

2009-01-01

Background: Additional tasks that are assumed to disturb standing postural control can be divided in added motor or added cognitive tasks. It is unknown which type of task causes the most disturbances of postural control in elderly. Objective: The aim of this study was to determine whether the dual

Postural steadiness and ankle force variability in peripheral neuropathy

Science.gov (United States)

Paxton, Roger J.; Feldman-Kothe, Caitlin; Trabert, Megan K.; Hitchcock, Leah N.; Reiser, Raoul F.; Tracy, Brian L.

2015-01-01

Introduction The purpose was to determine the effect of peripheral neuropathy (PN) on motor output variability for ankle muscles of older adults, and the relation between ankle motor variability and postural stability in PN patients. Methods Older adults with (O-PN) and without PN (O), and young adults (Y) underwent assessment of standing postural stability and ankle muscle force steadiness. Results O-PN displayed impaired ankle muscle force control and postural stability compared with O and Y groups. For O-PN, the amplitude of plantarflexor force fluctuations was moderately correlated with postural stability under no-vision conditions (r = 0.54, P = 0.01). Discussion The correlation of variations in ankle force with postural stability in PN suggests a contribution of ankle muscle dyscontrol to the postural instability that impacts physical function for older adults with PN. PMID:26284897

Posture and Texting: Effect on Balance in Young Adults.

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Nurul Retno Nurwulan

Full Text Available Using a mobile phone while doing another activity is a common dual-task activity in our daily lives. This study examined the effect of texting on the postural stability of young adults. Twenty college students were asked to perform static and dynamic postural stability tasks. Traditional COP and multivariate multiscale entropy (MMSE were used to assess the static postural stability and the Star Excursion Balance Test (SEBT was used to assess the dynamic postural stability. Results showed that (1 texting impaired postural stability, (2 the complexity index did not change much although the task conditions changed, and (3 performing texting is perceived to be more difficult.

Postural Response Signal Characteristics Identified by Method of Developed Statokinesigram

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Barbolyas Boris

2015-12-01

Full Text Available Human postural system is taken as complex biological system with specific input and output time characteristics, in this study. Evaluation of measured output characteristics is useful in medical diagnostics or in describing postural system disorders. System theory principle provide suitable basis for postural signals analysis. Participating volunteers were instructed to maintain quiet upright stance posture on firm support surface of stabilometric platform for 60s. Postural system actuation was realized by vibration stimuli applied bilaterally on Achilles tendons for 20s. Postural reaction signal, its time profile and static and dynamic characteristics were evaluated by Method of Developed Statokinesigram Trajectory (MDST.

Head movements and postures as pain behavior

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Al-Hamadi, Ayoub; Limbrecht-Ecklundt, Kerstin; Walter, Steffen; Traue, Harald C.

2018-01-01

Pain assessment can benefit from observation of pain behaviors, such as guarding or facial expression, and observational pain scales are widely used in clinical practice with nonverbal patients. However, little is known about head movements and postures in the context of pain. In this regard, we analyze videos of three publically available datasets. The BioVid dataset was recorded with healthy participants subjected to painful heat stimuli. In the BP4D dataset, healthy participants performed a cold-pressor test and several other tasks (meant to elicit emotion). The UNBC dataset videos show shoulder pain patients during range-of-motion tests to their affected and unaffected limbs. In all videos, participants were sitting in an upright position. We studied head movements and postures that occurred during the painful and control trials by measuring head orientation from video over time, followed by analyzing posture and movement summary statistics and occurrence frequencies of typical postures and movements. We found significant differences between pain and control trials with analyses of variance and binomial tests. In BioVid and BP4D, pain was accompanied by head movements and postures that tend to be oriented downwards or towards the pain site. We also found differences in movement range and speed in all three datasets. The results suggest that head movements and postures should be considered for pain assessment and research. As additional pain indicators, they possibly might improve pain management whenever behavior is assessed, especially in nonverbal individuals such as infants or patients with dementia. However, in advance more research is needed to identify specific head movements and postures in pain patients. PMID:29444153

Effects of disease severity and medication state on postural control asymmetry during challenging postural tasks in individuals with Parkinson's disease.

Science.gov (United States)

Barbieri, Fabio A; Polastri, Paula F; Baptista, André M; Lirani-Silva, Ellen; Simieli, Lucas; Orcioli-Silva, Diego; Beretta, Victor S; Gobbi, Lilian T B

2016-04-01

The aim of this study was to investigate the effects of disease severity and medication state on postural control asymmetry during challenging tasks in individuals with Parkinson's disease (PD). Nineteen people with PD and 11 neurologically healthy individuals performed three standing task conditions: bipedal standing, tandem and unipedal adapted standing; the individuals with PD performed the tasks in ON and OFF medication state. The participants with PD were distributed into 2 groups according to disease severity: unilateral group (n=8) and bilateral group (n=11). The two PD groups performed the evaluations both under and without the medication. Two force plates were used to analyze the posture. The symmetric index was calculated for various of center of pressure. ANOVA one-way (groups) and two-way (PD groups×medication), with repeated measures for medication, were calculated. For main effects of group, the bilateral group was more asymmetric than CG. For main effects of medication, only unipedal adapted standing presented effects of PD medication. There was PD groups×medication interaction. Under the effects of medication, the unilateral group presented lower asymmetry of RMS in anterior-posterior direction and area than the bilateral group in unipedal adapted standing. In addition, the unilateral group presented lower asymmetry of mean velocity, RMS in anterior-posterior direction and area in unipedal standing and area in tandem adapted standing after a medication dose. Postural control asymmetry during challenging postural tasks was dependent on disease severity and medication state in people with PD. The bilateral group presented higher postural control asymmetry than the control and unilateral groups in challenging postural tasks. Finally, the medication dose was able to reduce postural control asymmetry in the unilateral group during challenging postural tasks. Copyright © 2015 Elsevier B.V. All rights reserved.

Designing an Incentive Contract Menu for Sustaining the Electricity Market

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Ying Yu

2015-12-01

Full Text Available This paper designs an incentive contract menu to achieve long-term stability for electricity prices in a day-ahead electricity market. A bi-level Stackelberg game model is proposed to search for the optimal incentive mechanism under a one-leader and multi-followers gaming framework. A multi-agent simulation platform was developed to investigate the effectiveness of the incentive mechanism using an independent system operator (ISO and multiple power generating companies (GenCos. Further, a Q-learning approach was implemented to analyze and assess the response of GenCos to the incentive menu. Numerical examples are provided to demonstrate the effectiveness of the incentive contract.

An investigation into essential aspects of posture in primary school ...

African Journals Online (AJOL)

Postures of the subjects were analysed by means of photographic images using the pro forma of Barlow (1956, 1990). The majority of the executives had malposture with 2.3%, 23.3%, 58.1% and 16.3% and 6.3% of the subjects being categorised with slight postural defects, severe postural defects, very severe postural ...

Association between temporomandibular disorders and abnormal head postures

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Evandro Francisco FAULIN

2015-01-01

Full Text Available This study examines the possible correlation between the prevalence of temporomandibular disorders (TMD and different head postures in the frontal and sagittal planes using photographs of undergraduate students in the School of Dentistry at the Universidade de Brasília - UnB, Brazil. In this nonrandomized, cross-sectional study, the diagnoses of TMD were made with the Research Diagnostic Criteria (RDC/TMD axis I. The craniovertebral angle was used to evaluate forward head posture in the sagittal plane, and the interpupillary line was used to measure head tilt in the frontal plane. The measurements to evaluate head posture were made using the Software for the Assessment of Posture (SAPO. Students were divided into two study groups, based on the presence or absence of TMD. The study group comprised 46 students and the control group comprised 80 students. Data about head posture and TMD were analyzed with the Statistical Package for the Social Sciences, version 13. Most cases of TMD were classified as degenerative processes (group III, followed by disk displacement (group II and muscle disorders (group I. There was no sex predominance for the type of disorder. No association was found between prevalence rates for head postures in the frontal plane and the occurrence of TMD. The same result was found for the association of TMD diagnosis with craniovertebral angle among men and women, and the group that contained both men and women. Abnormal head postures were common among individuals both with and without TMD. No association was found between head posture evaluated in the frontal and sagittal planes and TMD diagnosis with the use of RDC/TMD.

Relationship between static foot posture and foot mobility

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McPoil Thomas G

2011-01-01

Full Text Available Abstract Background It is not uncommon for a person's foot posture and/or mobility to be assessed during a clinical examination. The exact relationship, however, between static posture and mobility is not known. Objective The purpose of this study was to determine the degree of association between static foot posture and mobility. Method The static foot posture and foot mobility of 203 healthy individuals was assessed and then analyzed to determine if low arched or "pronated" feet are more mobile than high arched or "supinated" feet. Results The study demonstrated that those individuals with a lower standing dorsal arch height and/or a wider standing midfoot width had greater mobility in their foot. In addition, those individuals with higher Foot Posture Index (FPI values demonstrated greater mobility and those with lower FPI values demonstrated less mobility. Finally, the amount of foot mobility that an individual has can be predicted reasonably well using either a 3 or 4 variable linear regression model. Conclusions Because of the relationship between static foot posture and mobility, it is recommended that both be assessed as part of a comprehensive evaluation of a individual with foot problems.

Characterization of postural control impairment in women with fibromyalgia

Science.gov (United States)

Sempere-Rubio, Núria; López-Pascual, Juan; Aguilar-Rodríguez, Marta; Cortés-Amador, Sara; Espí-López, Gemma; Villarrasa-Sapiña, Israel

2018-01-01

The main goal of this cross-sectional study was to detect whether women with fibromyalgia syndrome (FMS) have altered postural control and to study the sensory contribution to postural control. We also explored the possibility that self-induced anxiety and lower limb strength may be related to postural control. For this purpose, 129 women within an age range of 40 to 70 years were enrolled. Eighty of the enrolled women had FMS. Postural control variables, such as Ellipse, Root mean square (RMS) and Sample entropy (SampEn), in both directions (i.e. mediolateral and anteroposterior), were calculated under five different conditions. A force plate was used to register the center of pressure shifts. Furthermore, isometric lower limb strength was recorded with a portable dynamometer and normalized by lean body mass. The results showed that women with FMS have impaired postural control compared with healthy people, as they presented a significant increase in Ellipse and RMS values (pPostural control also worsens with the gradual alteration of sensory inputs in this population (p0.05). There were no significant correlations between postural control and lower limb strength (p>0.05). Therefore, women with FMS have impaired postural control that is worse when sensory inputs are altered but is not correlated with their lower limb strength. PMID:29723223

Effect of magnification loupes on dental hygiene student posture.

Science.gov (United States)

Maillet, J Peggy; Millar, A Michele; Burke, Jillian M; Maillet, Michelle A; Maillet, Wayne A; Neish, Nancy R

2008-01-01

The chair-side work posture of dental hygienists has long been a concern because of health-related problems potentially caused or exacerbated by poor posture. The purpose of this study was to investigate if using magnification loupes improved dental hygiene students' posture during provision of treatment. The treatment chosen was hand-scaling, and the effect of the timing of introduction of the loupes to students was also examined. Thirty-five novice dental hygiene students took part in the study. Each student was assessed providing dental hygiene care with and without loupes, thus controlling for innate differences in natural posture. Students were randomized into two groups. Group one used loupes in the first session and did not use them for the second session. Group two reversed this sequence. At the end of each session, all students were videotaped while performing scaling procedures. Their posture was assessed using an adapted version of Branson et al.'s Posture Assessment Instrument (PAI). Four raters assessed students at three time periods for nine posture components on the PAI. A paired t-test compared scores with and without loupes for each student. Scores showed a significant improvement in posture when using loupes (ppostural benefit is realized by requiring students to master the use of magnification loupes as early as possible within the curriculum.

Influence of pain on postural control in women with neck pain

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Juliana Soares

2013-04-01

Full Text Available The objective of this study was to investigate the influence of pain on postural control in women with neck pain and the relationship with possible changes in sensory systems and posture. The neck pain group was composed of women, aged between 20 and 50years, complaining of neck pain for more than three months; the control group was composed of women without complaints of neck pain. For the characterization of the groups, we used anamnesis, neck disability index and Visual Analogue Scale. Postural balance was assessed on force platform. Postural balance with manipulation of the sensory systems was measured by Foam Laser Dynamic Posturography, exposing the individual to six sensory organization tests. Posture was assessed by the Postural Assessment Software. The normality of the variables were verified using Shapiro-Wilk test, Student’s t-test and Mann-Whitney test for comparison between groups, with a significance level of5%. Groups were homogeneous in demographic variables. We observed higher amplitude and displacement velocity of the center of pressure in the neck pain group, showing greater postural balance. There were significant diferences incraniovertebral angle, showing forward head posture in symptomatic women. In dynamics posturography, we observed a difference between the groups: the score obtainedin the six sensory conditions showed that neck pain group presented greater balance impairment. Neck pain and forward head posture have a deleterious effect on postural control in symptomatic women, both in the static posture and dynamic posture.

Postural Variables in Girls Practicing Volleyball

Science.gov (United States)

Grabara, Malgorzata; Hadzik, Andrzej

2009-01-01

Study aim: To assess body posture of young female volleyball players in relation to their untrained mates. Material and methods: A group of 42 volleyball players and another of 43 untrained girls, all aged 13-16 years were studied with respect to their body posture indices by using computer posturography. Spinal angles and curvatures were…

Postural changes in dental hygienists. Four-year longitudinal study.

Science.gov (United States)

Barry, R M; Woodall, W R; Mahan, J M

1992-01-01

Numerous surveys identify the occurrence of musculoskeletal complaints as a concern in dentistry. However, no longitudinal data exist to indicate whether postural changes occur as a result of practicing dental hygiene. The purpose of this preliminary, four-year longitudinal study was to investigate whether any postural changes developed during the hygienists' clinical education and/or during subsequent dental hygiene practice after one and/or two years. It was anticipated that the awkward positions and intense physical demands placed on hygienists might initiate musculoskeletal problems, but that no postural changes would occur over this short period of time. Nine of 10 dental hygienists in the graduating class of 1987 were surveyed for existing musculoskeletal complaints, and the subjects were photographed for a measurement of postural change. Responses from participants indicated an increase in musculoskeletal-related complaints in each of the six areas investigated. The photographic findings indicated that one of the nine hygienists showed an increase in forward head posture, a postural change.

Barnacle geese achieve significant energetic savings by changing posture.

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Tickle, Peter G; Nudds, Robert L; Codd, Jonathan R

2012-01-01

Here we report the resting metabolic rate in barnacle geese (Branta leucopsis) and provide evidence for the significant energetic effect of posture. Under laboratory conditions flow-through respirometry together with synchronous recording of behaviour enabled a calculation of how metabolic rate varies with posture. Our principal finding is that standing bipedally incurs a 25% increase in metabolic rate compared to birds sitting on the ground. In addition to the expected decrease in energy consumption of hindlimb postural muscles when sitting, we hypothesise that a change in breathing mechanics represents one potential mechanism for at least part of the observed difference in energetic cost. Due to the significant effect of posture, future studies of resting metabolic rates need to take into account and/or report differences in posture.

THE PRESENCE OF POSTURAL DEFORMITIES OF THE YOUTH DEPENDING ON THE LEVEL OF PARENTS KNOWLADGE ABOUT DEFICIENT BODY POSTURE

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Zoran Bogdanović

2007-05-01

Full Text Available The subject of this study is deterimining the presence of postural deformities in sagittal view (defi cient kyphotic and lordotic body posture of the youth depanding on the level of parents knowladge about defi cient body posture. The complete content of the program was conducted in the territory of the city of Kragujevac in several elementary schools, comprising 299 students of the 5th grade and their parents. The object of this study was to determine the number of students with defi cient kyphotic and lordotic body posture, to determine the presence of dis arrangements depanding on the gender and to determine the presence of kyphotic and lordotic deformity depanding on the parents level of information about defi ciant body posture among children. Kyphotic deformity of the examiners of male population is mostly present in the group of parents who are poorly informed about body posture defi ciency. Regarding examiners of female population , the presence of deformation is equally divided on the group of parents who expressed themselves as being very well, those who are undecided and those who are poorly informed. The more signifi cant presence of kyphotic deformity is at examiners of male population than at the examiners of female population while the higher presence of lordotic deformity is at the examiners of female population. Regarding female population we can observe the highest presence of deformation in the group of parents who are undecided while the other groups are very equabal by the presence of deformation. Stated measures impose a statement that it is necessary to continuosly work on both - children education and parents education aiming to recognize posture defi ciency and physical deformation of school and preschool population and all of this with the object of reducing the deformation and on time detecting certain disarrangements and taking adaquate measures for its senctuary

Effects of posture on postoperative pulmonary function

DEFF Research Database (Denmark)

Nielsen, K G; Holte, Kathrine; Kehlet, H

2003-01-01

BACKGROUND: Pulmonary morbidity is still a relevant complication to major surgery despite improvements in surgical technique and anaesthetic methods. Postoperative posture may be a pathogenic factor, but the effects of changes in postoperative posture on pulmonary function have not been reviewed...

Multisensory training for postural sway control in non-injured elderly ...

African Journals Online (AJOL)

Multisensory training for postural sway control in non-injured elderly females. ... Elderly adults demonstrate increased postural sway, which may ultimately lead to falls. ... Keywords: multisensory training, postural sway control, balance ability, ...

Sustainability of a public system for plasma collection, contract fractionation and plasma-derived medicinal product manufacturing.

Science.gov (United States)

Grazzini, Giuliano; Ceccarelli, Anna; Calteri, Deanna; Catalano, Liviana; Calizzani, Gabriele; Cicchetti, Americo

2013-09-01

In Italy, the financial reimbursement for labile blood components exchanged between Regions is regulated by national tariffs defined in 1991 and updated in 1993-2003. Over the last five years, the need for establishing standard costs of healthcare services has arisen critically. In this perspective, the present study is aimed at defining both the costs of production of blood components and the related prices, as well as the prices of plasma-derived medicinal products obtained by national plasma, to be used for interregional financial reimbursement. In order to analyse the costs of production of blood components, 12 out 318 blood establishments were selected in 8 Italian Regions. For each step of the production process, driving costs were identified and production costs were. To define the costs of plasma-derived medicinal products obtained by national plasma, industrial costs currently sustained by National Health Service for contract fractionation were taken into account. The production costs of plasma-derived medicinal products obtained from national plasma showed a huge variability among blood establishments, which was much lower after standardization. The new suggested plasma tariffs were quite similar to those currently in force. Comparing the overall costs theoretically sustained by the National Health Service for plasma-derived medicinal products obtained from national plasma to current commercial costs, demonstrates that the national blood system could gain a 10% cost saving if it were able to produce plasma for fractionation within the standard costs defined in this study. Achieving national self-sufficiency through the production of plasma-derived medicinal products from national plasma, is a strategic goal of the National Health Service which must comply not only with quality, safety and availability requirements but also with the increasingly pressing need for economic sustainability.

The distribution contracts: an Iberian approach

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Sónia de Carvalho

2016-12-01

Full Text Available The contracts of commercial distribution are indispensable legal instruments to the development of the economic activity. The distribution, since the industrial revolution, acquired autonomy, given the necessity of specialized intermediation to distribute good and products. In this process, the structural organization of the distribution process suffered mutations, starting to assume a set of activities aiming at adjusting demand to supply, including, among others, clients canvassing, after-sales services, financing and assumption of risks, advisory services, promotion and advertising. The insufficiency of traditional contracts of purchase and sales and commission to satisfy the distributive needs caused by the industrial revolution will justify the development of new contractual schemes, such us agency contract, commercial concession and franchising. The obligation of the distributer to ensure the interests of the producer and to promote the distribution of the goods and services of the producer, in the context of a lasting relation of cooperation between the parts, through which the distributer is incorporated, with greater or minor intensity, in the producer distribution network, allowed us to sustain, as affirmed in the Portuguese and European literature, that distribution contracts could be framed in the same legal category. These contracts, as contracts that were shaped by praxis, do not have, with exception of agency contract, a legal framework in Portugal and Spain. It has been discussed in literature if agency contract legal framework can be applied, by analogy, to the contracts that fit in the legal category of distribution contracts. This paper aims at analyzing the legal framework of contracts of distribution in these legal systems, with the purpose to discuss the analogical application of the agency contract to these contracts.

Development of the Coordination between Posture and Manual Control

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Haddad, Jeffrey M.; Claxton, Laura J.; Keen, Rachel; Berthier, Neil E.; Riccio, Gary E.; Hamill, Joseph; Van Emmerik, Richard E. A.

2012-01-01

Studies have suggested that proper postural control is essential for the development of reaching. However, little research has examined the development of the coordination between posture and manual control throughout childhood. We investigated the coordination between posture and manual control in children (7- and 10-year-olds) and adults during…

Cerebellar transcranial direct current stimulation improves adaptive postural control.

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Poortvliet, Peter; Hsieh, Billie; Cresswell, Andrew; Au, Jacky; Meinzer, Marcus

2018-01-01

Rehabilitation interventions contribute to recovery of impaired postural control, but it remains a priority to optimize their effectiveness. A promising strategy may involve transcranial direct current stimulation (tDCS) of brain areas involved in fine-tuning of motor adaptation. This study explored the effects of cerebellar tDCS (ctDCS) on postural recovery from disturbance by Achilles tendon vibration. Twenty-eight healthy volunteers participated in this sham-ctDCS controlled study. Standing blindfolded on a force platform, four trials were completed: 60 s quiet standing followed by 20 min active (anodal-tDCS, 1 mA, 20 min, N = 14) or sham-ctDCS (40 s, N = 14) tDCS; three quiet standing trials with 15 s of Achilles tendon vibration and 25 s of postural recovery. Postural steadiness was quantified as displacement, standard deviation and path derived from the center of pressure (COP). Baseline demographics and quiet standing postural steadiness, and backwards displacement during vibration were comparable between groups. However, active-tDCS significantly improved postural steadiness during vibration and reduced forward displacement and variability in COP derivatives during recovery. We demonstrate that ctDCS results in short-term improvement of postural adaptation in healthy individuals. Future studies need to investigate if multisession ctDCS combined with training or rehabilitation interventions can induce prolonged improvement of postural balance. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Postural habits of young adults and possibilities of modification.

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Nowotny-Czupryna, Olga; Czupryna, Krzysztof; Bąk, Krzysztof; Wróblewska, Ewa; Rottermund, Jerzy

2013-01-01

The aim of the study was to assess postural habits in young, healthy people, identify correlations between postural errors and pain and attempt to modify bad habits. 144 people, aged 18-23 were enrolled. The intervention consisted of 4 stages: Stage 1 - identification of postural habits, description of responses to stress, back pain frequency and intensity (Jackson & Moskowitz); Stage 2 - correction of habitual position with the help of a physiotherapist, briefing about ergonomic everyday behaviours and consequences of continued non-ergonomic behaviours, Stage 3 - follow-up examination: self-assessment of changes, evaluation of the effects of modifications, determination of causes for discontinuing the behaviour modification programme, where applicable; and Stage 4 - final examination, assessment of results. Correlations were sought between inappropriate postural behaviour in various positions and between non-ergonomic postural behaviour and pain location and response to stress. Statistical analysis was carried out with Excel and Statistica v. 7.1. A non-parametric χ(2) test was used at phabit. 3. An attempt to modify non-ergonomic postural behaviours usually results in pain, which may act as a demotivating factor. 4. Discomfort associated with the modification of habitual postural behaviours is reduced after 3-4 months of regular training.

Postural stability in young and old women

DEFF Research Database (Denmark)

Jørgensen, Martin Grønbech

at an early stage, good knowledge and sensitive measurements of postural stability are essential. In addition, in order to develop effective intervention strategies such knowledge is of major importance. However, no single postural stability parameter has effectively been able to identify individuals at risk...... of falling. Hence, there is a strong need for development and identification of sensitive postural sway parameters in various demographic groups. The aim of this study was to explore differences in postural stability between physically active old (O) and young (Y) women using newly developed sway parameters....... METHODS AND MATERIALS: Center of pressure (CoP) excursion was measured (100 Hz) by force plate (AMTI) analysis in old (72.5±6.3 years) and young (25.8±1.6 years) women during static 2-leg (bilateral) and 1-leg (unilateral) standing (15-s) with eyes opened. RESULTS: O demonstrated elevated CoP sway length...

Postural effects when cycling in late pregnancy.

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O'Neill, Maureen E; Cooper, Karen A; Boyce, E Stewart; Hunyor, Stephen N

2006-12-01

This study assessed if upright cycling is preferable to semi-recumbent cycling during pregnancy. Healthy women with low risk singleton pregnancies were tested at 34-38 weeks gestation. They cycled for 12 min, either semi-recumbent (45 degrees, n = 27) or upright (n = 23), at 135-145 beats min(-1). When semi-recumbent, minute ventilation was greater (pposture-independent. All increased with exercise (p0.05). Small post-exercise fetal heart rate increases (by 8 beats min(-1), ppostures (n = 11 in each sub-group), with no adverse changes. Fetal heart rate accelerations and uterine activity (n = 11 in each sub-group) were not influenced by posture or exercise. (1) Neither posture had a distinct advantage. (2) Both postures were safe for short duration cycling. (3) The same target maternal heart rates are suitable for both postures because they resulted in similar oxygen consumptions and fetal heart rates.

Classifying Transition Behaviour in Postural Activity Monitoring

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James BRUSEY

2009-10-01

Full Text Available A few accelerometers positioned on different parts of the body can be used to accurately classify steady state behaviour, such as walking, running, or sitting. Such systems are usually built using supervised learning approaches. Transitions between postures are, however, difficult to deal with using posture classification systems proposed to date, since there is no label set for intermediary postures and also the exact point at which the transition occurs can sometimes be hard to pinpoint. The usual bypass when using supervised learning to train such systems is to discard a section of the dataset around each transition. This leads to poorer classification performance when the systems are deployed out of the laboratory and used on-line, particularly if the regimes monitored involve fast paced activity changes. Time-based filtering that takes advantage of sequential patterns is a potential mechanism to improve posture classification accuracy in such real-life applications. Also, such filtering should reduce the number of event messages needed to be sent across a wireless network to track posture remotely, hence extending the system’s life. To support time-based filtering, understanding transitions, which are the major event generators in a classification system, is a key. This work examines three approaches to post-process the output of a posture classifier using time-based filtering: a naïve voting scheme, an exponentially weighted voting scheme, and a Bayes filter. Best performance is obtained from the exponentially weighted voting scheme although it is suspected that a more sophisticated treatment of the Bayes filter might yield better results.

Barnacle geese achieve significant energetic savings by changing posture.

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Peter G Tickle

Full Text Available Here we report the resting metabolic rate in barnacle geese (Branta leucopsis and provide evidence for the significant energetic effect of posture. Under laboratory conditions flow-through respirometry together with synchronous recording of behaviour enabled a calculation of how metabolic rate varies with posture. Our principal finding is that standing bipedally incurs a 25% increase in metabolic rate compared to birds sitting on the ground. In addition to the expected decrease in energy consumption of hindlimb postural muscles when sitting, we hypothesise that a change in breathing mechanics represents one potential mechanism for at least part of the observed difference in energetic cost. Due to the significant effect of posture, future studies of resting metabolic rates need to take into account and/or report differences in posture.

The relationship between the stomatognathic system and body posture

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Antonino Cuccia

2009-01-01

Full Text Available In recent years, many researchers have investigated the various factors that can influence body posture: mood states, anxiety, head and neck positions, oral functions (respiration, swallowing, oculomotor and visual systems, and the inner ear. Recent studies indicate a role for trigeminal afferents on body posture, but this has not yet been demonstrated conclusively. The present study aims to review the papers that have shown a relationship between the stomatognathic system and body posture. These studies suggest that tension in the stomatognathic system can contribute to impaired neural control of posture. Numerous anatomical connections between the stomatognathic system's proprioceptive inputs and nervous structures are implicated in posture (cerebellum, vestibular and oculomotor nuclei, superior colliculus. If the proprioceptive information of the stomatognathic system is inaccurate, then head control and body position may be affected. In addition, the present review discusses the role the myofascial system plays in posture. If confirmed by further research, these considerations can improve our understanding and treatment of muscular-skeletal disorders that are associated with temporomandibular joint disorders, occlusal changes, and tooth loss.

The Relationship Between the Stomatognathic System and Body Posture

Science.gov (United States)

Cuccia, Antonino; Caradonna, Carola

2009-01-01

In recent years, many researchers have investigated the various factors that can influence body posture: mood states, anxiety, head and neck positions, oral functions (respiration, swallowing), oculomotor and visual systems, and the inner ear. Recent studies indicate a role for trigeminal afferents on body posture, but this has not yet been demonstrated conclusively. The present study aims to review the papers that have shown a relationship between the stomatognathic system and body posture. These studies suggest that tension in the stomatognathic system can contribute to impaired neural control of posture. Numerous anatomical connections between the stomatognathic system’s proprioceptive inputs and nervous structures are implicated in posture (cerebellum, vestibular and oculomotor nuclei, superior colliculus). If the proprioceptive information of the stomatognathic system is inaccurate, then head control and body position may be affected. In addition, the present review discusses the role the myofascial system plays in posture. If confirmed by further research, these considerations can improve our understanding and treatment of muscular-skeletal disorders that are associated with temporomandibular joint disorders, occlusal changes, and tooth loss. PMID:19142553

Do older adults perceive postural constraints for reach estimation?

Science.gov (United States)

Cordova, Alberto; Gabbard, Carl

2014-01-01

BACKGROUND/STUDY CONTEXT: Recent evidence indicates that older persons have difficulty mentally representing intended movements. Furthermore, in an estimation of reach paradigm using motor imagery, a form of mental representation, older persons significantly overestimated their ability compared with young adults. The authors tested the notion that older adults may also have difficulty perceiving the postural constraints associated with reach estimation. The authors compared young (Mage = 22 years) and older (Mage = 67) adults on reach estimation while seated and in a more postural demanding standing and leaning forward position. The expectation was a significant postural effect with the standing condition, as evidenced by reduced overestimation. Whereas there was no difference between groups in the seated condition (both overestimated), older adults underestimated whereas the younger group once again overestimated in the standing condition. From one perspective, these results show that older adults do perceive postural constraints in light of their own physical capabilities. That is, that group perceived greater postural demands with the standing posture and elected to program a more conservative strategy, resulting in underestimation.

Otolith and Vertical Canal Contributions to Dynamic Postural Control

Science.gov (United States)

Black, F. Owen

1999-01-01

The objective of this project is to determine: 1) how do normal subjects adjust postural movements in response to changing or altered otolith input, for example, due to aging? and 2) how do patients adapt postural control after altered unilateral or bilateral vestibular sensory inputs such as ablative inner ear surgery or ototoxicity, respectively? The following hypotheses are under investigation: 1) selective alteration of otolith input or abnormalities of otolith receptor function will result in distinctive spatial, frequency, and temporal patterns of head movements and body postural sway dynamics. 2) subjects with reduced, altered, or absent vertical semicircular canal receptor sensitivity but normal otolith receptor function or vice versa, should show predictable alterations of body and head movement strategies essential for the control of postural sway and movement. The effect of altered postural movement control upon compensation and/or adaptation will be determined. These experiments provide data for the development of computational models of postural control in normals, vestibular deficient subjects and normal humans exposed to unusual force environments, including orbital space flight.

Lung volumes during sustained microgravity on Spacelab SLS-1

Science.gov (United States)

Elliott, Ann R.; Prisk, G. Kim; Guy, Harold J. B.; West, John B.

1994-01-01

Gravity is known to influence the mechanical behavior of the lung and chest wall. However, the effect of sustained microgravity (microgravity) on lung volumes has not been reported. Pulmonary function tests were performed by four subjects before, during, and after 9 days of microgravity exposure. Ground measurements were made in standing and supine postures. Tests were performed using a bag-in-box-and-flowmeter system and a respiratory mass spectrometer. Measurements included functional residual capacity (FRC), expiratory reserve volume (ERV), residual volume (RV), inspiratory and expiratory vital capacities (IVC and EVC), and tidal volume (V9sub T)). Total lung capacity (TLC) was derived from the measured EVC and RV values. With preflight standing values as a comparison, FRC was significantly reduced by 15% (approximately 500 ml) in microgravity and 32% in the supine posture. ERV was reduced by 10 - 20% in microgravity and decreased by 64% in the supine posture. RV was significantly reduced by 18% (310 ml) in microgravity but did not significantly change in the supine posture compared with standing. IVC and EVC were slightly reduced during the first 24 h of microgravity but returned to 1-G standing values within 72 h of microgravity exposure. IVC and EVC in the supine posture were significantly reduced by 12% compared with standing. During microgravity, V(sub T) decreased by 15% (approximately 90 ml), but supine V(sub T) was unchanged compared with preflight standing values. TLC decreased by approximately 8% during microgravity and in the supine posture compared with preflight standing. The reductions in FRC, ERV, and RV during microgravity are probably due to the cranial shift of the diaphragm, an increase in intrathoracic blood volume, and more uniform alveolar expansion.

SEMG analysis of astronaut upper arm during isotonic muscle actions with normal standing posture

Science.gov (United States)

Qianxiang, Zhou; Chao, Ma; Xiaohui, Zheng

sEMG analysis of astronaut upper arm during isotonic muscle actions with normal standing posture*1 Introduction Now the research on the isotonic muscle actions by using Surface Electromyography (sEMG) is becoming a pop topic in fields of astronaut life support training and rehabilitations. And researchers paid more attention on the sEMG signal processes for reducing the influence of noise which is produced during monitoring process and the fatigue estimation of isotonic muscle actions with different force levels by using the parameters which are obtained from sEMG signals such as Condition Velocity(CV), Median Frequency(MDF), Mean Frequency(MNF) and so on. As the lucubrated research is done, more and more research on muscle fatigue issue of isotonic muscle actions are carried out with sEMG analysis and subjective estimate system of Borg scales at the same time. In this paper, the relationship between the variable for fatigue based on sEMG and the Borg scale during the course of isotonic muscle actions of the upper arm with different contraction levels are going to be investigated. Methods 13 young male subjects(23.4±2.45years, 64.7±5.43Kg, 171.7±5.41cm) with normal standing postures were introduced to do isotonic actions of the upper arm with different force levels(10% MVC, 30%MVC and 50%MVC). And the MVC which means maximal voluntary contraction was obtained firstly in the experiment. Also the sEMG would be recorded during the experiments; the Borg scales would be recorded for each contraction level. By using one-third band octave method, the fatigue variable (p) based on sEMG were set up and it was expressed as p = i g(fi ) · F (fi ). And g(fi ) is defined as the frequent factor which was 0.42+0.5 cos(π fi /f0 )+0.08 cos(2π fi /f0 ), 0 f0 . According to the equations, the p could be computed and the relationship between variable p and the Borg scale would be investigated. Results In the research, three kinds of fitted curves between variable p and Borg

A comparison of three observational techniques for assessing postural loads in industry.

Science.gov (United States)

Kee, Dohyung; Karwowski, Waldemar

2007-01-01

This study aims to compare 3 observational techniques for assessing postural load, namely, OWAS, RULA, and REBA. The comparison was based on the evaluation results generated by the classification techniques using 301 working postures. All postures were sampled from the iron and steel, electronics, automotive, and chemical industries, and a general hospital. While only about 21% of the 301 postures were classified at the action category/level 3 or 4 by both OWAS and REBA, about 56% of the postures were classified into action level 3 or 4 by RULA. The inter-method reliability for postural load category between OWAS and RULA was just 29.2%, and the reliability between RULA and REBA was 48.2%. These results showed that compared to RULA, OWAS, and REBA generally underestimated postural loads for the analyzed postures, irrespective of industry, work type, and whether or not the body postures were in a balanced state.

Implementing Coordinative Contracts between Manufacturer and Retailer in a Reverse Supply Chain

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Sung Wook Yoon

2016-09-01

Full Text Available There is an increasing need for company awareness of environmental problems and sustainable business practices. As a post-consumption activity, the reverse supply chain aims to extract value from products at the end of their lifecycle; it offers a means of pursuing sustainability through recycling, remanufacturing, refurbishing, and reusing. This study develops a series of procedures for implementing contracts between manufacturers and retailers to maximize individual profits and total profits through the reverse supply chain. To analyze the effects of the decision strategies made by parties acting on non-coordinative (decentralized and coordinative contracts, we model a two-echelon reverse supply chain environment using a system dynamics approach. In this study, we examine three cooperative contracts with differing shares of cost and profit between the two parties. Each contract is analyzed according to the following three contract processes. First, the manufacturer proposes a set of contracts that can be considered by the retailer. Second, the retailer evaluates the proposed contracts and chooses the one that is expected to maximize profits. Finally, the retailer and manufacturer adjust the parameters of the best contract to achieve the mutual goal of the supply chain. Using the experimental results, we discuss the best coordinative strategy between manufacturer and retailer for maximizing profits in the reverse supply chain.

Holding a handle for balance during continuous postural perturbations – immediate and transitionary effects on whole body posture

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Jernej Camernik

2016-09-01

Full Text Available When balance is exposed to perturbations, hand contacts are often used to assist postural control. We investigated the immediate and the transitionary effects of supportive hand contacts during continuous anteroposterior perturbations of stance by automated waist-pulls. Ten young adults were perturbed for five minutes and required to maintain balance by holding to a stationary, shoulder-high handle and following its removal. Centre of pressure (COP displacement, hip, knee, and ankle angles, leg and trunk muscle activity and handle contact forces were acquired. The analysis of results show that COP excursions are significantly smaller when the subjects utilize supportive hand contact and that the displacement of COP is strongly correlated to the perturbation force and significantly larger in the anterior than posterior direction. Regression analysis of hand forces revealed that subjects utilized the hand support significantly more during the posterior than anterior perturbations. Moreover, kinematical analysis showed that utilization of supportive hand contacts alters posture of the whole body and that postural readjustments after the release of the handle occur at different time scales in the hip, knee, and ankle joints. Overall, our findings show that supportive hand contacts are efficiently used for balance control during continuous postural perturbations and that utilization of a handle has significant immediate and transitionary effects on whole body posture.

Variation in posture quality across musical instruments and its impact during performances.

Science.gov (United States)

Blanco-Piñeiro, Patricia; Díaz-Pereira, M Pino; Martínez Vidal, Aurora

2018-06-01

Bad posture increases the risk that a musician may suffer from musculoskeletal disorders. This study compared posture quality required by different instruments or families of instruments. Using an ad-hoc postural observation instrument embracing 11 postural variables, four experts evaluated the postures of 100 students attending a Spanish higher conservatory of music. The agreement of the experts' evaluations was statistically confirmed by a Cohen's κ value between 0.855 and 1.000 and a Kendall value between 0.709 and 1.000 (p instrument families and seated posture with respect to pelvic attitude, dorsal curvature and head alignment in both sagittal and frontal planes. This analysis also showed an association between instrument families and standing posture with respect to the frontal plane of the axis of gravity, pelvic attitude, head alignment in the frontal plane, the sagittal plane of the shoulders and overall posture. While certain postural defects appear to be common to all families of instruments, others are more characteristic of some families than others. The instrument associated with the best posture quality was the bagpipe, followed by percussion and strings.

Recognition of dance-like actions: memory for static posture or dynamic movement?

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Vicary, Staci A; Robbins, Rachel A; Calvo-Merino, Beatriz; Stevens, Catherine J

2014-07-01

Dance-like actions are complex visual stimuli involving multiple changes in body posture across time and space. Visual perception research has demonstrated a difference between the processing of dynamic body movement and the processing of static body posture. Yet, it is unclear whether this processing dissociation continues during the retention of body movement and body form in visual working memory (VWM). When observing a dance-like action, it is likely that static snapshot images of body posture will be retained alongside dynamic images of the complete motion. Therefore, we hypothesized that, as in perception, posture and movement would differ in VWM. Additionally, if body posture and body movement are separable in VWM, as form- and motion-based items, respectively, then differential interference from intervening form and motion tasks should occur during recognition. In two experiments, we examined these hypotheses. In Experiment 1, the recognition of postures and movements was tested in conditions in which the formats of the study and test stimuli matched (movement-study to movement-test, posture-study to posture-test) or mismatched (movement-study to posture-test, posture-study to movement-test). In Experiment 2, the recognition of postures and movements was compared after intervening form and motion tasks. These results indicated that (1) the recognition of body movement based only on posture is possible, but it is significantly poorer than recognition based on the entire movement stimulus, and (2) form-based interference does not impair memory for movements, although motion-based interference does. We concluded that, whereas static posture information is encoded during the observation of dance-like actions, body movement and body posture differ in VWM.

[Occlusion and posture: is there evidence of correlation?].

Science.gov (United States)

Michelotti, A; Manzo, P; Farella, M; Martina, R

1999-11-01

The observation that the masticatory system and the postural body regulating system are anatomically and functionally related, has led to postulate several hypotheses of correlation between occlusal and postural disturbances. In the last decade, these arguments have gained a great social impact, also because they have been broadly spread by the mass-media. As a consequence, there has been a growing number of patients seeking concomitant occlusal and postural treatments. The aim of this study was to review critically the current evidence of correlation between the two systems; this in order to address clinical issues for the management of patients. Methodology of the studies reviewed has been evaluated according to the criteria suggested by Storey and Rugh 20 rif. Although there are some evidences of correlation between occlusion and posture, this appears limited to the cranio-cervical tract of the column and tends to disappear when descending in cranio-caudal direction. On the basis of this review of the literature, it's not advisable to treat postural imbalance by means of occlusal treatment or vice versa, particularly if the therapeutic modalities are irreversible.

Screening initial entry training trainees for postural faults and low back or hip pain.

Science.gov (United States)

Lane, John R

2014-01-01

The frequency of postural faults and postural awareness in military trainees has not been assessed. Five hundred Soldiers entering Advanced Individual Training were screened for standing posture and completed an anonymous questionnaire during inprocessing. Postural faults were identified in 202 subjects. Chi square analysis demonstrated a relationship between posture observed and posture reported: 87% of subjects with postural faults were unaware of postural faults; 12% with proper posture reported having poor posture. Subjects reported comparable frequencies of back pain and hip pain with postural faults (33.2%, 21.2%) and without faults (28.5%, 14.7%). Anonymous reporting was higher than formal reporting and requests for care during the same period (37% vs 3.4%).

Assessment of postural instability in patients with Parkinson's disease.

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Błaszczyk, J W; Orawiec, R; Duda-Kłodowska, D; Opala, G

2007-10-01

Postural instability is one of the most disabling features of idiopathic Parkinson's disease (PD). In this study, we focused on postural instability as the main factor predisposing parkinsonians to falls. For this purpose, changes in sway characteristics during quiet stance due to visual feedback exclusion were studied. We searched for postural sway measures that could be potential discriminators for an increased fall risk. A group of 110 subjects: 55 parkinsonians (Hoehn and Yahr: 1-3), and 55 age-matched healthy volunteers participated in the experiment. Their spontaneous sway characteristics while standing quiet with eyes open and eyes closed were analyzed. We found that an increased mediolateral sway and sway area while standing with eyes closed are characteristic of parkinsonian postural instability and may serve to quantify well a tendency to fall. These sway indices significantly correlated with disease severity rated both by the Hoehn and Yahr scale as well as by the Motor Section of the UPDRS. A forward shift of a mean COP position in parkinsonians which reflects their flexed posture was also significantly greater to compare with the elderly subjects and exhibited a high sensitivity to visual conditions. Both groups of postural sway abnormalities identified here may be used as accessible and reliable measures which allow for quantitative assessment of postural instability in Parkinson's disease.

Exercise and Posture

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... About Spondylitis › Treatment Information › Exercise & Posture Print Page Exercise Exercise is an integral part of any spondylitis ... For First Responders For Chiropractors Research Article Archive Exercise Guidelines Having an exercise program that accomplishes your ...

[The impact of different sports on posture regulation].

Science.gov (United States)

Schwesig, R; Kluttig, A; Leuchte, S; Becker, S; Schmidt, H; Esperer, H D

2009-09-01

Previous work has suggested that both the level of activity and the type of sport may have a major impact on postural control. However, no systematic investigation has been performed regarding the various types of professional sports. Particularly, the impact of competitional sports on the postural subsystems has not been elucidated so far. The aim of this study was to investigate the influence of the major professional sport types, such as handball, gymnastics, swimming, and shooting, on the subsystems of postural control. We also tested the hypothesis that specific types of sport have specific effects on postural regulation. 155 competitive male and female athletes (handball: n = 30; gymnastics: n = 44; swimming: n = 50; shooting: n = 31), and 34 age- and gender-matched controls were investigated using the Interactive Balance System (IBS; Tetrax Inc., Ramat Gan, Israel). The following spectral and time-domain indices were determined: power in the following frequency bands: P(F1) (0.03 - 0.1 Hz), P(F)(2 - 4) (0.1 - 0.5 Hz), P(F)(5 - 6) (0.5 - 1.0 Hz), P(F)(7 - 8) (> 1.0 Hz), stability index (STABI), and synchronisation index (SYN). Shooting athletes exhibited significantly smaller values of P(F1) (p = 0.003), P(F)(2 - 4) (p sports exert different effects on the various subsystems of posture control, where especially shooting competitors demonstrate a significantly better posture regulation. Those effects can be parameterised and quantified with the IBS which thus enables an efficient and purposeful training. Furthermore, the IBS is highly suitable for aptitude screening in sports with high posture regulatory demands (shooting competitions, gymnastics, diving etc.). Copyright Georg Thieme Verlag KG Stuttgart . New York .

Motor Variability during Sustained Contractions Increases with Cognitive Demand in Older Adults

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Vanden Noven, Marnie L.; Pereira, Hugo M.; Yoon, Tejin; Stevens, Alyssa A.; Nielson, Kristy A.; Hunter, Sandra K.

2014-01-01

To expose cortical involvement in age-related changes in motor performance, we compared steadiness (force fluctuations) and fatigability of submaximal isometric contractions with the ankle dorsiflexor muscles in older and young adults and with varying levels of cognitive demand imposed. Sixteen young (20.4 ± 2.1 year: 8 men, 9 women) and 17 older adults (68.8 ± 4.4 years: 9 men, 8 women) attended three sessions and performed a 40 s isometric contraction at 5% maximal voluntary contraction (MVC) force followed by an isometric contraction at 30% MVC until task failure. The cognitive demand required during the submaximal contractions in each session differed as follows: (1) high-cognitive demand session where difficult mental math was imposed (counting backward by 13 from a 4-digit number); (2) low-cognitive demand session which involved simple mental math (counting backward by 1); and (3) control session with no mental math. Anxiety was elevated during the high-cognitive demand session compared with other sessions for both age groups but more so for the older adults than young adults (p  Older adults had larger force fluctuations than young adults during: (1) the 5% MVC task as cognitive demand increased (p  = 0.007), and (2) the fatiguing contraction for all sessions (p  = 0.002). Time to task failure did not differ between sessions or age groups (p  > 0.05), but the variability between sessions (standard deviation of three sessions) was greater for older adults than young (2.02 ± 1.05 vs. 1.25 ± 0.51 min, p  age and was exacerbated when cognitive demand was imposed, and may be related to modulation of synergist and antagonist muscles and an altered neural strategy with age originating from central sources. These data have significant implications for cognitively demanding low-force motor tasks that are relevant to functional and ergonomic in an aging workforce. PMID:24904410

Eye Movements Affect Postural Control in Young and Older Females.

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Thomas, Neil M; Bampouras, Theodoros M; Donovan, Tim; Dewhurst, Susan

2016-01-01

Visual information is used for postural stabilization in humans. However, little is known about how eye movements prevalent in everyday life interact with the postural control system in older individuals. Therefore, the present study assessed the effects of stationary gaze fixations, smooth pursuits, and saccadic eye movements, with combinations of absent, fixed and oscillating large-field visual backgrounds to generate different forms of retinal flow, on postural control in healthy young and older females. Participants were presented with computer generated visual stimuli, whilst postural sway and gaze fixations were simultaneously assessed with a force platform and eye tracking equipment, respectively. The results showed that fixed backgrounds and stationary gaze fixations attenuated postural sway. In contrast, oscillating backgrounds and smooth pursuits increased postural sway. There were no differences regarding saccades. There were also no differences in postural sway or gaze errors between age groups in any visual condition. The stabilizing effect of the fixed visual stimuli show how retinal flow and extraocular factors guide postural adjustments. The destabilizing effect of oscillating visual backgrounds and smooth pursuits may be related to more challenging conditions for determining body shifts from retinal flow, and more complex extraocular signals, respectively. Because the older participants matched the young group's performance in all conditions, decreases of posture and gaze control during stance may not be a direct consequence of healthy aging. Further research examining extraocular and retinal mechanisms of balance control and the effects of eye movements, during locomotion, is needed to better inform fall prevention interventions.

[Self-evaluation of posture by elderly people with or without thoracic kyphosis].

Science.gov (United States)

Gasparotto, Lívia Pimenta Renó; Reis, Camila Costa Ibiapina; Ramos, Luiz Roberto; Santos, José Francisco Quirino Dos

2012-03-01

This article lists the differences between self-perception of body posture among the elderly suffering from postural alterations or not, in order to ascertain whether self-evaluation of posture can lead to preventive measures. Eighteen cases from the elderly population participated in the EPIDOSO project at UNIFESP and were subjected to postural evaluation. Postures were photographed and copies given to the participants and their subsequent comments were analyzed by the qualitative method. The narratives were taped and cataloguedusingthe technique of theoretical axial and selective coding from the perspective of symbolic interactionism. A passive attitude was identified among the elderly in relation to postural alterations. There is a distortion of body image by those with postural deviation. Participants with adequate spinal alignment were more conscious about body posture and the importance of this being assimilated in the phases prior to aging. The adoption of postural self-care seems to occur in the earlier stages of aging and preventive measures should be implemented at this stage. Lack of concern about posture is linked to the concept of the elderly regarding the notion that aging is, in itself, the accumulation of inevitably simultaneous or successive dysfunctions.

Posture-Motor and Posture-Ideomotor Dual-Tasking: A Putative Marker of Psychomotor Retardation and Depressive Rumination in Patients With Major Depressive Disorder.

Science.gov (United States)

Aftanas, Lyubomir I; Bazanova, Olga M; Novozhilova, Nataliya V

2018-01-01

Background: Recent studies have demonstrated that the assessment of postural performance may be a potentially reliable and objective marker of the psychomotor retardation (PMR) in the major depressive disorder (MDD). One of the important facets of MDD-related PMR is reflected in disrupted central mechanisms of psychomotor control, heavily influenced by compelling maladaptive depressive rumination. In view of this we designed a research paradigm that included sequential execution of simple single-posture task followed by more challenging divided attention posture tasks, involving concurring motor and ideomotor workloads. Another difficulty dimension assumed executing of all the tasks with eyes open (EO) (easy) and closed (EC) (difficult) conditions. We aimed at investigating the interplay between the severity of MDD, depressive rumination, and efficiency of postural performance. Methods: Compared with 24 age- and body mass index-matched healthy controls (HCs), 26 patients with MDD sequentially executed three experimental tasks: (1) single-posture task of maintaining a quiet stance (ST), (2) actual posture-motor dual task (AMT); and (3) mental/imaginary posture-motor dual task (MMT). All the tasks were performed in the EO and the EC conditions. The primary dependent variable was the amount of kinetic energy ( E ) expended for the center of pressure deviations (CoPDs), whereas the absolute divided attention cost index showed energy cost to the dual-tasking vs. the single-posture task according to the formula: Δ E = ( E Dual-task - E Single-task ). Results: The signs of PMR in the MDD group were objectively indexed by deficient posture control in the EC condition along with overall slowness of fine motor and ideomotor activity. Another important and probably more challenging feature of the findings was that the posture deficit manifested in the ST condition was substantially and significantly attenuated in the MMT and AMT performance dual-tasking activity. A multiple

Validity and reliability of a dental operator posture assessment instrument (PAI).

Science.gov (United States)

Branson, Bonnie G; Williams, Karen B; Bray, Kimberly Krust; Mcllnay, Sandy L; Dickey, Diana

2002-01-01

Basic operating posture is considered an important occupational health issue for oral health care clinicians. It is generally agreed that the physical posture of the operator, while providing care, should be such that all muscles are in a relaxed, well-balanced, and neutral position. Postures outside of this neutral position are likely to cause musculoskeletal discomfort. To date, the range of the neutral operator position has not been well-defined; nor have any specific instruments been identified that can quantitatively or semi-quantitatively assess dental operator posture. This paper reports on the development of an instrument that can be used to semi-quantitatively evaluate postural components. During the first phase of the study, an expert panel defined the basic parameters for acceptable, compromised, and harmful operator postures and established face validity of a posture assessment instrument (PAI). During the second phase, the PAI was tested for reliability using generalizability theory. Four raters tested the instrument for reliability. Overall, total PAI scores were similar amongst three of the raters, with the fourth rater's scores being slightly greater than the other three. The main effect of the rater on individual postural components was moderate, indicating that rater variance contributed to 11.9% of total variance. The PAI measures posture as it occurs and will have numerous applications when evaluating operator performance in the dental and dental hygiene education setting. Also, the PAI will prove useful when examining the effects of operator posture and musculoskeletal disorders.

Body surface posture evaluation: construction, validation and protocol of the SPGAP system (Posture evaluation rotating platform system).

Science.gov (United States)

Schwertner, Debora Soccal; Oliveira, Raul; Mazo, Giovana Zarpellon; Gioda, Fabiane Rosa; Kelber, Christian Roberto; Swarowsky, Alessandra

2016-05-04

Several posture evaluation devices have been used to detect deviations of the vertebral column. However it has been observed that the instruments present measurement errors related to the equipment, environment or measurement protocol. This study aimed to build, validate, analyze the reliability and describe a measurement protocol for the use of the Posture Evaluation Rotating Platform System (SPGAP, Brazilian abbreviation). The posture evaluation system comprises a Posture Evaluation Rotating Platform, video camera, calibration support and measurement software. Two pilot studies were carried out with 102 elderly individuals (average age 69 years old, SD = ±7.3) to establish a protocol for SPGAP, controlling the measurement errors related to the environment, equipment and the person under evaluation. Content validation was completed with input from judges with expertise in posture measurement. The variation coefficient method was used to validate the measurement by the instrument of an object with known dimensions. Finally, reliability was established using repeated measurements of the known object. Expert content judges gave the system excellent ratings for content validity (mean 9.4 out of 10; SD 1.13). The measurement of an object with known dimensions indicated excellent validity (all measurement errors reality. To verify the images of objects with known dimensions the values for the width and height were, respectively, CV 0.88 (width) and 2.33 (height), SD 0.22 (width) and 0.35 (height), minimum and maximum values 24.83-25.2 (width) and 14.56 - 15.75 (height). In the analysis of different images (similar) of an individual, greater discrepancies were observed in the values found. The cervical index, for example, presented minimum and maximum values of 15.38 and 37.5, a coefficient of variation of 0.29 and a standard deviation of 6.78. The SPGAP was shown to be a valid and reliable instrument for the quantitative analysis of body posture with applicability and

Análise comparativa entre avaliação postural visual e por fotogrametria computadorizada Comparative analysis between visual and computerized photogrammetry postural assessment

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DH Iunes

2009-08-01

Full Text Available OBJETIVOS: Comparar a concordância interobservador da avaliação postural visual e por fotogrametria e verificar se os resultados quantitativos da fotogrametria correspondem à detecção de simetrias e assimetrias pela avaliação postural visual qualitativa. MÉTODOS: Vinte e um voluntários (24±1,9 anos foram inicialmente avaliados visualmente por três fisioterapeutas experientes que preencheram um protocolo de avaliação postural. Em seguida tiveram fotografados a face e o corpo todo nos planos frontal anterior, posterior e sagital. As fotos foram utilizadas para traçar ângulos a partir de marcadores fixados à pele, em vários pontos anatômicos, que são referências frequentes na avaliação postural tradicional. Essas fotografias foram analisadas por três examinadores diferentes da avaliação postural visual. A concordância de cada método de avaliação postural foi avaliada pelos Coeficientes de Cramer V ou de PHI, considerando-se um nível de significância de 5%. RESULTADOS: Foi encontrada uma concordância entre os examinadores que utilizaram a fotogrametria para todos os segmentos avaliados. Não apresentaram concordância os segmentos comissura labial (p=0,00, acrômio clavicular (p=0,01, esternoclavicular (p=0,00, espinhas ilíacas anterior e posterior (p=0,00 e p=0,01 e ângulo inferior da escápula (p=0,00, que foram analizados por meio da avaliação postural visual. A comparação entre a fotogrametria e a avaliação postural visual demonstrou que o grau de concordância entre os dois métodos de avaliação foi pouco significativo para alguns segmentos do membro inferior e pelve. CONCLUSÕES: Nessas condições experimentais, os dados da fotogrametria não podem ser correlacionados com os dados da avaliação postural visual. A avaliação postural visual apresentou dados menos concordantes do que a fotogrametria, devendo ser questionada sua utilização como gold-standart.OBJECTIVES: To compare the interobserver

Development of anticipatory postural adjustments during locomotion in children.

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Hirschfeld, H; Forssberg, H

1992-08-01

1. Anticipatory postural adjustments were studied in children (6-14 yr of age) walking on a treadmill while pulling a handle. Electromyographs (EMGs) and movements were recorded from the left arm and leg. 2. Postural activity in the leg muscles preceded voluntary arm muscle activity in all age groups, including the youngest children (6 yr of age). The latency to both leg and arm muscle activity, from a triggering audio signal, decreased with age. 3. In older children the latency to both voluntary and postural activity was influenced by the phase of the step cycle. The shortest latency to the first activated postural muscle occurred during single support phase in combination with a long latency to arm muscle activity. 4. In the youngest children, there was no phase-dependent modulation of the latency to the activation of the postural muscles. The voluntary activity was delayed during the beginning of the support phase resulting in a long delay between leg and arm muscle activity. 5. The postural muscle activation pattern was modified in a phase-dependent manner in all children. Lateral gastrocnemius (LG) and hamstring muscles (HAM) were activated during the early support phase, whereas tibialis anterior (TA) and quadriceps (Q) muscles were activated during the late support phase and during the swing phase. However, in the 6-yr-old children, LG was also activated in the swing phase. LG was activated before the HAM activity in the youngest children but after HAM in 14-yr-old children and adults. 6. The occurrence of LG activity in postural responses before heel strike suggests an immature (nonplantigrade) gating of postural activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Foot posture in basketball players with history of the shin splint

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Saeed Forghany

2013-07-01

Full Text Available Introduction: Shin splint is one of the common injuries in most athletes. Although the relationship between abnormal foot posture and shin splint has been reported previously but, the relation between foot posture and shin splint has not been well documented. The aim of this study was to explore the relationship between foot postures in basketball players and the history of shin splint. Materials and Methods: Thirty Iranian male basketball players who had experience of shin splint during last three months were participated in this study. Foot Posture Index (FPI-6 was used as the measure of foot posture. Talar head palpation, curvature at the lateral malleoli, inversion/eversion of the calcaneus, prominence in the region of the talonavicular joint, congruence of the medial longitudinal arch, abduction /adduction of the forefoot on the rear foot were 6 items which were assessed with FPI in the standing position. Foot posture was defined as ‘normal’, ‘supinated’ or ‘pronated. Data were collected and analyzed by SPSS, version16. Results: Most participants showed abnormal foot posture (%80. Fifty-three percent of subjects had pronated foot (%53 and 10% did hyper-pronation. The foot postures of 17% of participants were in supination. The results of this study did not show a significant difference in foot posture between right and left foot (P > 0.05. Conclusion: abnormal foot posture were common (%80 in basketball players with the history of shin splints. These findings could support this idea that the footwear and orthotic prescription both can prevent and treat basketball players with history of shin splints. Keywords: Foot posture, Shin splints, Basketball

Use of Video Analysis System for Working Posture Evaluations

Science.gov (United States)

McKay, Timothy D.; Whitmore, Mihriban

1994-01-01

In a work environment, it is important to identify and quantify the relationship among work activities, working posture, and workplace design. Working posture may impact the physical comfort and well-being of individuals, as well as performance. The Posture Video Analysis Tool (PVAT) is an interactive menu and button driven software prototype written in Supercard (trademark). Human Factors analysts are provided with a predefined set of options typically associated with postural assessments and human performance issues. Once options have been selected, the program is used to evaluate working posture and dynamic tasks from video footage. PVAT has been used to evaluate postures from Orbiter missions, as well as from experimental testing of prototype glove box designs. PVAT can be used for video analysis in a number of industries, with little or no modification. It can contribute to various aspects of workplace design such as training, task allocations, procedural analyses, and hardware usability evaluations. The major advantage of the video analysis approach is the ability to gather data, non-intrusively, in restricted-access environments, such as emergency and operation rooms, contaminated areas, and control rooms. Video analysis also provides the opportunity to conduct preliminary evaluations of existing work areas.

Quantitative Postural Analysis of Children With Congenital Visual Impairment.

Science.gov (United States)

de Pádua, Michelle; Sauer, Juliana F; João, Silvia M A

2018-01-01

The aim of this study was to compare the postural alignment of children with visual impairment with that of children without visual impairment. The sample studied was 74 children of both sexes ages 5 to 12 years. Of these, 34 had visual impairment and 40 were control children. Digital photos from the standing position were used to analyze posture. Postural variables, such as tilt of the head, shoulder position, scapula position, lateral deviation of the spine, ankle position in the frontal plane and head posture, angle of thoracic kyphosis, angle of lumbar lordosis, pelvis position, and knee position in the frontal and sagittal planes, were measured with the Postural Assessment Software 0.63, version 36 (SAPO, São Paulo, Brazil), with markers placed in predetermined bony landmarks. The main results of this study showed that children with visual impairment have increased head tilt (P Visual impairment influences postural alignment. Children with visual impairment had increased head tilt, uneven shoulders, greater lateral deviation of the spine, thoracic kyphosis, lower lumbar lordosis, and more severe valgus deformities on knees. Copyright © 2017. Published by Elsevier Inc.

Effect of absence of vision on posture.

Science.gov (United States)

Alotaibi, Abdullah Z; Alghadir, Ahmad; Iqbal, Zaheen A; Anwer, Shahnawaz

2016-04-01

[Purpose] The visual system is one of the sensory systems that enables the body to assess and process information about the external environment. In the absence of vision, a blind person loses contact with the outside world and develops faulty motor patterns, which results in postural deficiencies. However, literature regarding the development of such deficiencies is limited. The aim of this study was to discuss the effect of absence of vision on posture, the possible biomechanics behind the resulting postural deficiencies, and strategies to correct and prevent them. [Subjects and Methods] Various electronic databases including PubMed, Medline, and Google scholar were examined using the words "body", "posture", "blind" and "absence of vision". References in the retrieved articles were also examined for cross-references. The search was limited to articles in the English language. [Results] A total of 74 papers were shortlisted for this review, most of which dated back to the 1950s and 60s. [Conclusion] Blind people exhibit consistent musculoskeletal deformities. Absence of vision leads to numerous abnormal sensory and motor interactions that often limit blind people in isolation. Rehabilitation of the blind is a multidisciplinary task. Specialists from different fields need to diagnose and treat the deficiencies of the blind together as a team. Before restoring the normal mechanics of posture and gait, the missing link with the external world should be reestablished.

Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size

OpenAIRE

Kubo, Tai; Kubo, Mugino O.

2016-01-01

Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade), yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. Accordi...

Correcting Poor Posture without Awareness or Willpower

Science.gov (United States)

Wernik, Uri

2012-01-01

In this article, a new technique for correcting poor posture is presented. Rather than intentionally increasing awareness or mobilizing willpower to correct posture, this approach offers a game using randomly drawn cards with easy daily assignments. A case using the technique is presented to emphasize the subjective experience of living with poor…

Lung function and postural changes during pregnancy.

Science.gov (United States)

Nørregaard, O; Schultz, P; Ostergaard, A; Dahl, R

1989-11-01

The aim of this study was to determine the effects of postural changes on lung function in pregnant women during the first, second, third trimester and post partum. A significant decrease in FRC, PEF and FEV1 was observed as a result of the postural changes. Arterial oxygenation, MVV and DLCO remained largely the same.

Relationship between posterior crossbite and postural alterations in children

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Juliana Jaqueline de Matos Lopes

2009-12-01

Full Text Available Objective: To evaluate the posture of individuals with functional posterior crossbite, malocclusion is one of the most in need of orthodontic treatment. Methods: This work presents an analysis of postural among children 6 to 12 years who present functional posterior cross bite of both genders who are in mixed dentition or no intervention prior orthodontic and orthopedic. Was obtained images in the plans: front and back where it was analyzed the asymmetry or symmetry of the individual in the image and in the lateral, anterior, a posterior or normality. Results: 100% had some kind of postural change, and the asymmetry between the scapulae (shoulder found the greatest change, as one of extreme importance in this age group represents a growing skeletal muscle. Conclusion: analyzes all of the children showed postural abnormalities and malocclusion are also of great importance not only to be treating the problem orally, but the postural problem with the help of a multidisciplinary team.

Clinical working postures of bachelor of oral health students.

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Horton, S J; Johnstone, C L; Hutchinson, C M W; Taylor, P A; Wade, K J

2011-09-01

To observe and describe the clinical working postures of final-year Bachelor of Oral Health (BOH) students. Pilot observational study. The University of Otago Faculty of Dentistry and School of Physiotherapy. Eight final-year BOH students voluntarily participated in this study, where postural data were collected using a digital video camera during a standard clinical treatment session. The postural data were analysed using 3D Match biomechanical software. Final-year BOH students who work in the seated position are exposed to neck flexion of greater than 35 degrees, together with trunk flexion greater than 20 degrees and bilateral elbow flexion greater than 90 degrees. The findings of this study agree with the findings of previous postural studies of dental professionals. Dental hygiene students, together with their clinical supervisors, need to be aware of the importance of good working posture early in their careers, and pay particular attention to the degree of neck flexion occurring for prolonged periods.

Effect of postural changes on ICP in healthy and ill subjects

DEFF Research Database (Denmark)

Petersen, Lonnie G; Juhler, Marianne

2015-01-01

to distinguish normal human physiology from disease entities such as idiopathic intracranial hypertension and normal pressure hydrocephalus, we investigated ICP in different body postures in both normal and ill subjects. METHODS: Thirty-one patients were included: four normal patients following complete removal......: upright standing, sitting in a chair, supine and right lateral lumbar puncture position. RESULTS: Linear regression of median ICP based on patient posture, group, and purpose of monitoring presented a significant model (p ... of differences in median ICP between body postures and supine ICP as the baseline, presented a highly significant model (p posture (p postures enabled...

Causes, Prevention and Correction of Impaired Posture in Children of Primary School Age

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В. А. Щирба

2016-09-01

Full Text Available Research Objective. The objective of our research was to provide theoretical substantiation and implement corrective gymnastics in practice for the purposes of prevention and correction of faults in schoolchildren’s posture. The main means for shaping the correct posture, preventing and correcting faults in posture are callisthenic routine and special corrective exercises. Research methods: anamnesis, somatoscopy, clinical and mathematical methods. Research results. The medical examination revealed that only six of 60 pupils had normal correctly shaped posture, which accounts for 10%. The posture of the other 90% of the pupils was impaired. The most common faults were: asymmetrical pectoral girdle and shoulder blades, stooping posture. The examination revealed 19 pupils with scoliotic posture, which accounts for 44 %. The posture of 24 pupils, or 40%, was hyperkyphotic and stooping. In other words, the posture of 84% of the pupils was scoliotic or hyperkyphotic. The rest of the pupils had flat and kypholordic posture. It is worth mentioning that some of the pupils examined had more serious disorders of their musculoskeletal system, namely: organic disorders, such as spinal disorders in the sagittal plane — the scoliosis types excluded from the study. Significantly, the first main reason of posture disorders is weakness of the pectoral muscle sling. Conclusions. The principal means of prevention and correction of impaired posture are using special physical exercises designed to create a muscular corpus and correct particular faults in posture. We therefore developed sets of exercises intended to correct posture defects and proposed them to the physical education teacher and class teachers.

Time-of-day influences postural balance in older adults

DEFF Research Database (Denmark)

Jorgensen, M G; Rathleff, Michael Skovdal; Laessoe, U

2012-01-01

Postural balance assessments are performed in both clinical and basic research settings on a daily basis. During a 24-h time span our physiology and physical performance undergo radical changes as we are influenced by the circadian rhythm. The time-of-day interaction on postural balance is unknow...... in older adults. The aim of this study was to investigate the time-of-day effect on postural balance in older adults....

Can smartwatches replace smartphones for posture tracking?

Science.gov (United States)

Mortazavi, Bobak; Nemati, Ebrahim; VanderWall, Kristina; Flores-Rodriguez, Hector G; Cai, Jun Yu Jacinta; Lucier, Jessica; Naeim, Arash; Sarrafzadeh, Majid

2015-10-22

This paper introduces a human posture tracking platform to identify the human postures of sitting, standing or lying down, based on a smartwatch. This work develops such a system as a proof-of-concept study to investigate a smartwatch's ability to be used in future remote health monitoring systems and applications. This work validates the smartwatches' ability to track the posture of users accurately in a laboratory setting while reducing the sampling rate to potentially improve battery life, the first steps in verifying that such a system would work in future clinical settings. The algorithm developed classifies the transitions between three posture states of sitting, standing and lying down, by identifying these transition movements, as well as other movements that might be mistaken for these transitions. The system is trained and developed on a Samsung Galaxy Gear smartwatch, and the algorithm was validated through a leave-one-subject-out cross-validation of 20 subjects. The system can identify the appropriate transitions at only 10 Hz with an F-score of 0.930, indicating its ability to effectively replace smart phones, if needed.

Static body postural misalignment in individuals with temporomandibular disorders: a systematic review

Science.gov (United States)

Chaves, Thaís C.; Turci, Aline M.; Pinheiro, Carina F.; Sousa, Letícia M.; Grossi, Débora B.

2014-01-01

BACKGROUND: The association between body postural changes and temporomandibular disorders (TMD) has been widely discussed in the literature, however, there is little evidence to support this association. OBJECTIVES: The aim of the present study was to conduct a systematic review to assess the evidence concerning the association between static body postural misalignment and TMD. METHOD: A search was conducted in the PubMed/Medline, Embase, Lilacs, Scielo, Cochrane, and Scopus databases including studies published in English between 1950 and March 2012. Cross-sectional, cohort, case control, and survey studies that assessed body posture in TMD patients were selected. Two reviewers performed each step independently. A methodological checklist was used to evaluate the quality of the selected articles. RESULTS: Twenty studies were analyzed for their methodological quality. Only one study was classified as a moderate quality study and two were classified as strong quality studies. Among all studies considered, only 12 included craniocervical postural assessment, 2 included assessment of craniocervical and shoulder postures,, and 6 included global assessment of body posture. CONCLUSION: There is strong evidence of craniocervical postural changes in myogenous TMD, moderate evidence of cervical postural misalignment in arthrogenous TMD, and no evidence of absence of craniocervical postural misalignment in mixed TMD patients or of global body postural misalignment in patients with TMD. It is important to note the poor methodological quality of the studies, particularly those regarding global body postural misalignment in TMD patients. PMID:25590441

Embeddedness as a facilitator of sustainable entrepreneurship

OpenAIRE

Dufays, Frédéric

2016-01-01

This conceptual paper makes the case for a strong embeddedness at all stages of sustainable entrepreneurship – opportunity identification and/or creation, evaluation, and exploitation. This strong embeddedness is argued to drive entrepreneurs towards sustainability through the set-up of long-term social contracts with multiple stakeholders. Building upon extant literature on sustainable, social, and environmental entrepreneurship and the framework of stakeholder theory, as well as the embedde...

Posture recognition based on fuzzy logic for home monitoring of the elderly.

Science.gov (United States)

Brulin, Damien; Benezeth, Yannick; Courtial, Estelle

2012-09-01

We propose in this paper a computer vision-based posture recognition method for home monitoring of the elderly. The proposed system performs human detection prior to the posture analysis; posture recognition is performed only on a human silhouette. The human detection approach has been designed to be robust to different environmental stimuli. Thus, posture is analyzed with simple and efficient features that are not designed to manage constraints related to the environment but only designed to describe human silhouettes. The posture recognition method, based on fuzzy logic, identifies four static postures and is robust to variation in the distance between the camera and the person, and to the person's morphology. With an accuracy of 74.29% of satisfactory posture recognition, this approach can detect emergency situations such as a fall within a health smart home.

Spatial and temporal analysis of postural control in dyslexic children.

Science.gov (United States)

Gouleme, Nathalie; Gerard, Christophe Loic; Bui-Quoc, Emmanuel; Bucci, Maria Pia

2015-07-01

The aim of this study is to examine postural control of dyslexic children using both spatial and temporal analysis. Thirty dyslexic (mean age 9.7±0.3years) and thirty non-dyslexic age-matched children participated in the study. Postural stability was evaluated using Multitest Equilibre from Framiral®. Posture was recorded in the following conditions: eyes open fixating a target (EO) and eyes closed (EC) on stable (-S-) and unstable (-U-) platforms. The findings of this study showed poor postural stability in dyslexic children with respect to the non-dyslexic children group, as demonstrated by both spatial and temporal analysis. In both groups of children postural control depends on the condition, and improves when the eyes are open on a stable platform. Dyslexic children have spectral power indices that are higher than in non-dyslexic children and they showed a shorter cancelling time. Poor postural control in dyslexic children could be due to a deficit in using sensory information most likely caused by impairment in cerebellar activity. The reliability of brain activation patterns, namely in using sensory input and cerebellar activity may explain the deficit in postural control in dyslexic children. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Motor variability during sustained contractions increases with cognitive demand in older adults

Directory of Open Access Journals (Sweden)

Marnie L Vanden Noven

2014-05-01

Full Text Available To expose cortical involvement in age-related changes in motor performance, we compared steadiness (force fluctuations and fatigability of submaximal isometric contractions with the ankle dorsiflexor muscles in older and young adults and with varying levels of cognitive demand imposed. Sixteen young (20 ± 2 yr: 8 men, 8 women and 17 older adults (69 ±4 yr: 9 men, 8 women attended three sessions and performed a 40 s isometric contraction at 5% maximal voluntary contraction (MVC force followed by an isometric contraction at 30% MVC until task failure. The cognitive demand required during the submaximal contractions in each session differed as follows: 1 high-cognitive demand session where difficult mental math was imposed (counting backward by 13 from a 4-digit number; 2 low-cognitive demand session which involved simple mental math (counting backward by one; and 3 control session with no mental math. Anxiety was elevated during the high-cognitive demand session compared with other sessions for both age groups but more so for the older adults than young adults (p0.05, but the variability between sessions (standard deviation [SD] of 3 sessions was greater for older adults than young (2.02 ± 1.05 min vs. 1.25 ± 0.51 min, P<0.05. Thus, variability in lower limb motor performance for low and moderate force isometric tasks increased with age and was exacerbated when cognitive demand was imposed, and may be related to modulation of synergist and antagonist muscles and an altered neural strategy with age originating from central sources. These data have significant implications for cognitively demanding low-force motor tasks that are relevant to functional and ergonomic in an aging workforce.

Regional differences in lumbar spinal posture and the influence of low back pain

Directory of Open Access Journals (Sweden)

Burnett Angus F

2008-11-01

Full Text Available Abstract Background Spinal posture is commonly a focus in the assessment and clinical management of low back pain (LBP patients. However, the link between spinal posture and LBP is not fully understood. Recent evidence suggests that considering regional, rather than total lumbar spine posture is important. The purpose of this study was to determine; if there are regional differences in habitual lumbar spine posture and movement, and if these findings are influenced by LBP. Methods One hundred and seventy female undergraduate nursing students, with and without LBP, participated in this cross-sectional study. Lower lumbar (LLx, Upper lumbar (ULx and total lumbar (TLx spine angles were measured using an electromagnetic tracking system in static postures and across a range of functional tasks. Results Regional differences in lumbar posture and movement were found. Mean LLx posture did not correlate with ULx posture in sitting (r = 0.036, p = 0.638, but showed a moderate inverse correlation with ULx posture in usual standing (r = -0.505, p Conclusion This study supports the concept of regional differences within the lumbar spine during common postures and movements. Global lumbar spine kinematics do not reflect regional lumbar spine kinematics, which has implications for interpretation of measures of spinal posture, motion and loading. BMI influenced regional lumbar posture and movement, possibly representing adaptation due to load.

Real-Time Hand Posture Recognition Using a Range Camera

Science.gov (United States)

Lahamy, Herve

The basic goal of human computer interaction is to improve the interaction between users and computers by making computers more usable and receptive to the user's needs. Within this context, the use of hand postures in replacement of traditional devices such as keyboards, mice and joysticks is being explored by many researchers. The goal is to interpret human postures via mathematical algorithms. Hand posture recognition has gained popularity in recent years, and could become the future tool for humans to interact with computers or virtual environments. An exhaustive description of the frequently used methods available in literature for hand posture recognition is provided. It focuses on the different types of sensors and data used, the segmentation and tracking methods, the features used to represent the hand postures as well as the classifiers considered in the recognition process. Those methods are usually presented as highly robust with a recognition rate close to 100%. However, a couple of critical points necessary for a successful real-time hand posture recognition system require major improvement. Those points include the features used to represent the hand segment, the number of postures simultaneously recognizable, the invariance of the features with respect to rotation, translation and scale and also the behavior of the classifiers against non-perfect hand segments for example segments including part of the arm or missing part of the palm. A 3D time-of-flight camera named SR4000 has been chosen to develop a new methodology because of its capability to provide in real-time and at high frame rate 3D information on the scene imaged. This sensor has been described and evaluated for its capability for capturing in real-time a moving hand. A new recognition method that uses the 3D information provided by the range camera to recognize hand postures has been proposed. The different steps of this methodology including the segmentation, the tracking, the hand

POSTURAL SHOCK IN PREGNANCY

Science.gov (United States)

Wilkening, Ralph L.; Knauer, John; Larson, Roger K.

1955-01-01

Signs and symptoms of shock may be produced in some patients in late pregnancy by putting them in the dorsal recumbent posture. Change from this position will relieve the condition. The features of the supine hypotensive syndrome can be duplicated by applying pressure to the abdomen with the patient in a lateral position. The postural variations of venous pressure, blood pressure, and pulse appear to be due to obstruction of venous return from the lower portion of the body caused by the large uterus of late pregnancy compressing the vena cava. When shock is observed in a woman in late pregnancy, she should be turned to a lateral position before more active measures of treatment are begun. ImagesFigure 1. PMID:14351983

Measuring postural sway in sitting

DEFF Research Database (Denmark)

Curtis, Derek John; Hansen, Lisbeth; Luun, Malene

2015-01-01

group appeared to result from an equally stable trunk supported on a less stable pelvis. Mediolateral marker sway and intersegmental angular sway showed a clearer age dependency. Trunk postural control does not appear to differ between children older and younger than 10 years old, but sagittal plane...... and younger than 10 years old, participated in this study. The children sat unsupported for 30 s while their posture and sway were quantified using stereophotogrammetry. The tendency in both age groups was to sit with a backward tilted pelvis and a kyphotic trunk. The sitting position was most varied...

Do children perceive postural constraints when estimating reach or action planning?

Science.gov (United States)

Gabbard, Carl; Cordova, Alberto; Lee, Sunghan

2009-03-01

Estimation of whether an object is reachable from a specific body position constitutes an important aspect in effective motor planning. Researchers who estimate reachability by way of motor imagery with adults consistently report the tendency to overestimate, with some evidence of a postural effect (postural stability hypothesis). This idea suggests that perceived reaching limits depend on an individual's perceived postural constraints. Based on previous work with adults, the authors expected a significant postural effect with the Reach 2 condition, as evidenced by reduced overestimation. Furthermore, the authors hypothesized that the postural effect would be greater in younger children. They then tested these propositions among children aged 7, 9, and 11 years by asking them to estimate reach while seated (Reach 1) and in the more demanding posture of standing on 1 foot and leaning forward (Reach 2). Results indicated no age or condition difference, therefore providing no support for a postural effect. When the authors compared these data to a published report of adults, a developmental difference emerged. That is, adults recognize the perceived postural constraint of the standing position resulting in under- rather than overestimation, as displayed in the seated condition. Although preliminary, these observations suggest that estimates of reach (action planning) continue to be refined between late childhood and young adulthood.

Multi-joint postural behavior in patients with knee osteoarthritis.

Science.gov (United States)

Turcot, Katia; Sagawa, Yoshimasa; Hoffmeyer, Pierre; Suvà, Domizio; Armand, Stéphane

2015-12-01

Previous studies have demonstrated balance impairment in patients with knee osteoarthritis (OA). Although it is currently accepted that postural control depends on multi-joint coordination, no study has previously considered this postural strategy in patients suffering from knee OA. The objectives of this study were to investigate the multi-joint postural behavior in patients with knee OA and to evaluate the association with clinical outcomes. Eighty-seven patients with knee OA and twenty-five healthy elderly were recruited to the study. A motion analysis system and two force plates were used to investigate the joint kinematics (trunk and lower body segments), the lower body joint moments, the vertical ground reaction force ratio and the center of pressure (COP) during a quiet standing task. Pain, functional capacity and quality of life status were also recorded. Patients with symptomatic and severe knee OA adopt a more flexed posture at all joint levels in comparison with the control group. A significant difference in the mean ratio was found between groups, showing an asymmetric weight distribution in patients with knee OA. A significant decrease in the COP range in the anterior-posterior direction was also observed in the group of patients. Only small associations were observed between postural impairments and clinical outcomes. This study brings new insights regarding the postural behavior of patients with severe knee OA during a quiet standing task. The results confirm the multi-joint asymmetric posture adopted by this population. Copyright © 2014 Elsevier B.V. All rights reserved.

Advantages and disadvantages of stiffness instructions when studying postural control.

Science.gov (United States)

Bonnet, Cédrick T

2016-05-01

To understand the maintenance of upright stance, researchers try to discover the fundamental mechanisms and attentional resources devoted to postural control and eventually to the performance of other tasks (e.g., counting in the head). During their studies, some researchers require participants to stand as steady as possible and other simply ask participants to stand naturally. Surprisingly, a clear and direct explanation of the usefulness of the steadiness requirement seems to be lacking, both in experimental and methodological discussions. Hence, the objective of the present note was to provide advantages and disadvantages of this steadiness requirement in studies of postural control. The advantages may be to study fundamental postural control, to eliminate useless postural variability, to control spurious body motions and to control the participants' thoughts. As disadvantages, this steadiness requirement only leads to study postural control in unnatural upright stance, it changes the focus of attention (internal vs. external) and the nature of postural control (unconscious vs. conscious), it increases the difficulty of a supposedly easy control task and it eliminates or reduces the opportunity to record exploratory behaviors. When looking carefully at the four advantages of the steadiness requirement, one can believe that they are, in fact, more disadvantageous than advantageous. Overall therefore, this requirement seems illegitimate and it is proposed that researchers should not use it in the study of postural control. They may use this requirement only if they search to know the limit until which participants can consciously reduce their postural sway. Copyright © 2015 Elsevier B.V. All rights reserved.

Testing postural control among various osteoporotic patient groups: A literature review

NARCIS (Netherlands)

de Groot, M.H.; van der Jagt-Willems, H.; van Campen, J.P.C.M.; Lems, W.F.; Lamoth, C.J.

2012-01-01

Aim: Osteoporosis can cause vertebral fractures, which might lead to a flexed posture, impaired postural control and consequently increased fall risk. Therefore, the aim of the present review was to examine whether postural control of patients with osteoporosis, vertebral fractures, thoracic

Testing postural control among various osteoporotic patient groups : A literature review

NARCIS (Netherlands)

de Groot, Maartje H.; van der Jagt-Willems, Hanna C.; van Campen, Jos P. C. M.; Lems, Willem F.; Lamoth, Claudine J. C.

2012-01-01

Aim: Osteoporosis can cause vertebral fractures, which might lead to a flexed posture, impaired postural control and consequently increased fall risk. Therefore, the aim of the present review was to examine whether postural control of patients with osteoporosis, vertebral fractures, thoracic

Body posture recognition and turning recording system for the care of bed bound patients.

Science.gov (United States)

Hsiao, Rong-Shue; Mi, Zhenqiang; Yang, Bo-Ru; Kau, Lih-Jen; Bitew, Mekuanint Agegnehu; Li, Tzu-Yu

2015-01-01

This paper proposes body posture recognition and turning recording system for assisting the care of bed bound patients in nursing homes. The system continuously detects the patient's body posture and records the length of time for each body posture. If the patient remains in the same body posture long enough to develop pressure ulcers, the system notifies caregivers to change the patient's body posture. The objective of recording is to provide the log of body turning for querying of patients' family members. In order to accurately detect patient's body posture, we developed a novel pressure sensing pad which contains force sensing resistor sensors. Based on the proposed pressure sensing pad, we developed a bed posture recognition module which includes a bed posture recognition algorithm. The algorithm is based on fuzzy theory. The body posture recognition algorithm can detect the patient's bed posture whether it is right lateral decubitus, left lateral decubitus, or supine. The detected information of patient's body posture can be then transmitted to the server of healthcare center by the communication module to perform the functions of recording and notification. Experimental results showed that the average posture recognition accuracy for our proposed module is 92%.

Effect of different head-neck-jaw postures on cervicocephalic kinesthetic sense.

Science.gov (United States)

Zafar, H; Alghadir, A H; Iqbal, Z A

2017-12-01

To investigate the effect of different induced head-neck-jaw postures on head-neck relocation error among healthy subjects. 30 healthy adult male subjects participated in this study. Cervicocephalic kinesthetic sense was measured while standing, habitual sitting, habitual sitting with clenched jaw and habitual sitting with forward head posture during right rotation, left rotation, flexion and extension using kinesthetic sensibility test. Head-neck relocation error was least while standing, followed by habitual sitting, habitual sitting with forward head posture and habitual sitting with jaw clenched. However, there was no significant difference in error between different tested postures during all the movements. To the best of our knowledge, this is the first study to see the effect of different induced head-neck-jaw postures on head-neck position sense among healthy subjects. Assuming a posture for a short duration of time doesn't affect head-neck relocation error in normal healthy subjects.

Influence of head posture on the visual acuity of children with nystagmus

Directory of Open Access Journals (Sweden)

Ana Carla Ramos Vieira da Costa

2014-01-01

Full Text Available Purpose: Evaluate the relationship between the postural alignment of the head and possible interference in the view of children. Methods: We evaluated 11 children between 2 and 7 years of age of both sexes, with the visually impaired, who had nystagmus and head lock position. The test Lea Grating Acuity Test® was used to collect measurements of visual acuity. This applied on two occasions: with and without postural alignment of the head. For reliability of the postural alignment of the head, the slopes were measured by Fisiologic® software. Results: The children had a poorer performance after physiological postural alignment. This poor performance is possible due to loss of position lock nystagmus to gain postural alignment, said to be ideal. Postural compensations were observed, and sharply increased eyestrain. Conclusion: The pursuit of traditional postural alignment affect the visual response of children with visual impairments.

Is postural control affected by expertise in alpine skiing?

OpenAIRE

Noe, F; Paillard, T

2005-01-01

Objectives: This study examined the postural performance of two groups of male skiers competing at different levels and the consequences on postural control of the suppression of visual afferences by eye closure.

Postural strategies assessed with inertial sensors in healthy and parkinsonian subjects.

Science.gov (United States)

Baston, Chiara; Mancini, Martina; Schoneburg, Bernadette; Horak, Fay; Rocchi, Laura

2014-01-01

The present study introduces a novel instrumented method to characterize postural movement strategies to maintain balance during stance (ankle and hip strategy), by means of inertial sensors, positioned on the legs and on the trunk. We evaluated postural strategies in subjects with 2 types of Parkinsonism: idiopathic Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP), and in age-matched control subjects standing under perturbed conditions implemented by the Sensory Organization Test (SOT). Coordination between the upper and lower segments of the body during postural sway was measured using a covariance index over time, by a sliding-window algorithm. Afterwards, a postural strategy index was computed. We also measured the amount of postural sway, as adjunctive information to characterize balance, by the root mean square of the horizontal trunk acceleration signal (RMS). showed that control subjects were able to change their postural strategy, whilst PSP and PD subjects persisted in use of an ankle strategy in all conditions. PD subjects had RMS values similar to control subjects even without changing postural strategy appropriately, whereas PSP subjects showed much larger RMS values than controls, resulting in several falls during the most challenging SOT conditions (5 and 6). Results are in accordance with the corresponding clinical literature describing postural behavior in the same kind of subjects. The proposed strategy index, based on the use of inertial sensors on the upper and lower body segments, is a promising and unobtrusive tool to characterize postural strategies performed to attain balance. Copyright © 2014 Elsevier B.V. All rights reserved.

Postural disorders and spatial neglect in stroke patients: a strong association.

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Pérennou, Dominic

2006-01-01

In this paper we analyse the arguments for a strong association between spatial neglect and postural disorders and attempt to better understand the mechanisms which underlie that. We first provide a general overview of the available tools for a rational assessment of postural control in a clinical context. We then analyse the arguments in favour of a close relationship, although not necessarily causal, between spatial neglect and: 1) body orientation with respect to gravity (including verticality perception i.e. the visual vertical, the haptic vertical, and the postural vertical); 2) body stabilisation with respect to the base of support; 3) posturographic features of stroke patients; 4) and finally their postural disability in daily life. This second part of the paper is based both on the literature review and on results of our current research. Neglect patients show a dramatic postural disability, due both to problems in body orientation with respect to gravity and to problems in body stabilisation. It might be that these problems are partly caused by a neglect phenomenon bearing on graviceptive (somaesthetic > vestibular) and visual information serving postural control. This could correspond to a kind of postural neglect involving both the bodily and nonbodily domains of spatial neglect. The existence of distorsion(s) in the body scheme are also probably involved, especially to explain the weight-bearing asymmetry in standing, and probably an impaired multisegmental postural coordination leading to an impaired body stabilisation. The present paper explains why neglect patients show longer/worse recovery of postural-walking autonomy than other stroke patients.

Effects of Levodopa on Postural Strategies in Parkinson's disease.

Science.gov (United States)

Baston, Chiara; Mancini, Martina; Rocchi, Laura; Horak, Fay

2016-05-01

Altered postural control and balance are major disabling issues of Parkinson's disease (PD). Static and dynamic posturography have provided insight into PD's postural deficits; however, little is known about impairments in postural coordination. We hypothesized that subjects with PD would show more ankle strategy during quiet stance than healthy control subjects, who would include some hip strategy, and this stiffer postural strategy would increase with disease progression. We quantified postural strategy and sway dispersion with inertial sensors (one placed on the shank and one on the posterior trunk at L5 level) while subjects were standing still with their eyes open. A total of 70 subjects with PD, including a mild group (H&Y≤2, N=33) and a more severe group (H&Y≥3, N=37), were assessed while OFF and while ON levodopa medication. We also included a healthy control group (N=21). Results showed an overall preference of ankle strategy in all groups while maintaining balance. Postural strategy was significantly lower ON compared to OFF medication (indicating more hip strategy), but no effect of disease stage was found. Instead, sway dispersion was significantly larger in ON compared to OFF medication, and significantly larger in the more severe PD group compared to the mild. In addition, increased hip strategy during stance was associated with poorer self-perception of balance. Copyright © 2016 Elsevier B.V. All rights reserved.

Associations between Tactile Sensory Threshold and Postural Performance and Effects of Healthy Aging and Subthreshold Vibrotactile Stimulation on Postural Outcomes in a Simple Dual Task.

Science.gov (United States)

Dettmer, Marius; Pourmoghaddam, Amir; Lee, Beom-Chan; Layne, Charles S

2016-01-01

Specific activities that require concurrent processing of postural and cognitive tasks may increase the risk for falls in older adults. We investigated whether peripheral receptor sensitivity was associated with postural performance in a dual-task and whether an intervention in form of subthreshold vibration could affect performance. Ten younger (age: 20-35 years) and ten older adults (70-85 years) performed repeated auditory-verbal 1-back tasks while standing quietly on a force platform. Foot sole vibration was randomly added during several trials. Several postural control and performance measures were assessed and statistically analyzed (significance set to α-levels of .05). There were moderate correlations between peripheral sensitivity and several postural performance and control measures (r = .45 to .59). Several postural performance measures differed significantly between older and younger adults (p stimulation should focus on older adults whose balance is significantly affected.

Is there a relationship between foetal position and both preferred lying posture after birth and pattern of subsequent postural deformity in non-ambulant people with cerebral palsy?

Science.gov (United States)

Porter, D; Michael, S; Kirkwood, C

2010-09-01

A pattern of postural deformity was observed in a previous study that included an association between direction of spinal curvature and direction of windsweeping with more windswept deformities occurring to the right and lateral spinal curvatures occurring convex to the left. The direction of this pattern was found to be associated with preferred lying posture in early life. The aim of this study was to test the association between foetal position and both the preferred lying posture after birth, and the direction of subsequent postural deformity in non-ambulant children with cerebral palsy (CP). A retrospective cohort study was carried out involving 60 participants at level five on the gross motor function classification for CP. Foetal position during the last month of pregnancy was taken from antenatal records and parents were interviewed to identify preferred lying posture in the first year of life. At the time of the physical assessment ages ranged from 1 year and 1 month to 19 years with a median age of 13 years and 1 month. Foetal presentation was found to be associated with the preferred lying posture with participants carried in a left occipito-anterior/lateral position more likely to adopt a supine head right lying posture, and vice versa. An association was also observed between the foetal position and asymmetrical postural deformity occurring later in life with participants carried in a left occipito-anterior/lateral presentation more likely to have a convex left spinal curve, a lower left pelvic obliquity, and a windswept hip pattern to the right. Clinicians should be aware of the association between foetal presentation, asymmetrical lying posture, and the direction of subsequent postural deformity for severely disabled children. A hypothesis is described that might help to explain these findings.

The posture of adolescent male handball players: A two-year study.

Science.gov (United States)

Grabara, Małgorzata

2018-02-06

Young athletes at the stage of growth acceleration tend to exhibit increased susceptibility to postural abnormalities, especially in the trunk region. The aim of this study was to assess and compare the posture in male adolescent handball players over two years of regular training sessions. The study group comprised 21 handball players. At the start of the study 15 participants were aged 14 and 6 participants were aged 15 (mean 14.25 ± 0.58). The measurements were repeated three times. Posture was assessed with a photogrammetric method based on the moiré phenomenon. The analysis of posture relative to symmetry in the frontal and transverse planes did not reveal any significant differences between posture indicators obtained during the successive measurements. Sagittal plane posture indicators revealed significant changes in torso forward inclination angle and the shape of anteroposterior spinal curvatures. The latter consisted of significant deepening of the upper thoracic curve (angle α) and flattening of the lumbosacral curve (angle γ). A two-year period of handball training did not result in posture asymmetries in young male handball players. The observed changes in the shape of anteroposterior spinal curvatures might be related both to sports training and somatic parameters.

Spinal curvature and characteristics of postural change in pregnant women.

Science.gov (United States)

Okanishi, Natsuko; Kito, Nobuhiro; Akiyama, Mitoshi; Yamamoto, Masako

2012-07-01

Pregnant women often report complaints due to physiological and postural changes. Postural changes during pregnancy may cause low back pain and pelvic girdle pain. This study aimed to compare the characteristics of postural changes in pregnant compared with non-pregnant women. Prospective case-control study. Pregnancy care center. Fifteen women at 17-34 weeks pregnancy comprised the study group, while 10 non-pregnant female volunteers comprised the control group. Standing posture was evaluated in the sagittal plane with static digital pictures. Two angles were measured by image analysis software: (1) between the trunk and pelvis; and (2) between the trunk and lower extremity. Spinal curvature was measured with Spinal Mouse® to calculate the means of sacral inclination, thoracic and lumbar curvature and inclination. The principal components were calculated until eigenvalues surpassed 1. Three distinct factors with eigenvalues of 1.00-2.49 were identified, consistent with lumbosacral spinal curvature and inclination, thoracic spine curvature, and inclination of the body. These factors accounted for 77.2% of the total variance in posture variables. Eleven pregnant women showed postural characteristics of lumbar kyphosis and sacral posterior inclination. Body inclination showed a variety of patterns compared with those in healthy women. Spinal curvature demonstrated a tendency for lumbar kyphosis in pregnant women. Pregnancy may cause changes in spinal curvature and posture, which may in turn lead to relevant symptoms. Our data provide a basis for investigating the effects of spinal curvature and postural changes on symptoms during pregnancy. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

Cumulative trauma disorders in the upper extremities: reliability of the postural and repetitive risk-factors index.

Science.gov (United States)

James, C P; Harburn, K L; Kramer, J F

1997-08-01

This study addresses test-retest reliability of the Postural and Repetitive Risk-Factors Index (PRRI) for work-related upper body injuries. This assessment was developed by the present authors. A repeated measures design was used to assess the test-retest reliability of a videotaped work-site assessment of subjects' movements. Ten heavy users of video display terminals (VDTs) from a local banking industry participated in the study. The 10 subjects' movements were videotaped for 2 hours on each of 2 separate days, while working on-site at their VDTs. The videotaped assessment, which utilized known postural risk factors for developing musculoskeletal disorder, pain, and discomfort in heavy VDT users (ie, repetitiveness, awkward and static postures, and contraction time), was called the PRRI. The videotaped movement assessments were subsequently analyzed in 15-minute sessions (five sessions per 2-hour videotape, which produced a total of 10 sessions over the 2 testing days), and each session was chosen randomly from the videotape. The subjects' movements were given a postural risk score according to the criteria in the PRRI. Each subject was therefore tested a total of 10 times (ie, 10 sessions), over two days. The maximum PRRI score for both sides of the body was 216 points. Reliability coefficients (RCs) for the PRRI scores were calculated, and the reliability of any one session met the minimum criterion for excellent reliability, which was .75. A two-way analysis of variance (ANOVA) confirmed that there was no statistically significant difference between sessions (p < .05). Calculations using the standard error of measurement (SEM) indicated that an individual tested once, on one day and with a PRRI score of 25, required a change of at least 8 points in order to be confident that a true change in score had occurred. The significant results from the reliability tests indicated that the PRRI was a reliable measurement tool that could be used by occupational health

Prism adaptation improves postural imbalance in neglect patients

NARCIS (Netherlands)

Nijboer, Tanja C W; Olthoff, Liselot; Van der Stigchel, Stefan; Visser-Meily, Johanna M a

2014-01-01

Several studies have found a negative relation between neglect and postural imbalance. The aim of the current study was to investigate the influence of a single session of prism adaptation on balance [i.e. mediolateral and anteroposterior center of pressure (CoP)] and postural sway (i.e. mean

ANALISIS KETIGGIAN MEJA KERJA YANG IDEAL TERHADAP POSTUR PEKERJA DIVISI CUTTING INDUSTRI GARMEN DENGAN POSTURE EVALUATION (PEI PADA VIRTUAL ENVIROMENT

Directory of Open Access Journals (Sweden)

Boy Nurtjahyo

2012-02-01

Full Text Available Penelitian ini mencoba untuk mengimplementasikan suatu metodologi untuk mempelajari, dalam lingkungan virtual, aspek ergonomi dari suatu tempat kerja di industri garmen. Variabel tempat kerja yang diteliti dalam penelitian ini adalah ketinggian meja kerja. Tujuan penelitian ini adalah mendapatkan konfigurasi ketinggian meja yang ideal bagi pekerja divisi cutting industri garmen. Tool yang digunakan dalam menyelesaikan skripsi ini adalah Posture Evaluation Index yang mengintegrasikan skor Low Back Analysis (LBA, Ovako Working Posture (OWAS, dan Rapid Upper Limb Assessment (RULA. Penentuan konfigurasi yang ideal dilakukan dengan mempertimbangkan jenis pekerjaan dan posisi kerja ketika melakukan pekerjaan tersebut, apakah dalam posisi duduk atau berdiri. Analisis dilakukan dengan menggunakan model manusia digital yang disediakan software Jack pada virtual environment. Hasil penelitian dapat digunakan sebagai referensi dalam merancang tempat kerja yang lebih baik secara ergonomis. Kata kunci : Ergonomi, Virtual Environment, Divisi Cutting  Industri Garmen, Posture Evaluation Index   Abstract   The research deals with the implementation of a methodology in order to study, in a virtual environment, the ergonomics of a work cell in garment industry. The work cell’s variable studied in this research is table height. The goal of this research is to determine an ideal table height for the workers of cutting division in garment industry. The tool to conduct this research is called Posture Evaluation Index (PEI which integrates the score of Low Back Analysis (LBA, Ovako Working Posture (OWAS, dan Rapid Upper Limb Assessment (RULA. The Determination of table height configuration is based on type of work and work position (standing or sitting. The research uses digital human model form Jack software in a virtual environment. The result from this research can be a reference for future work cell design. Keywords: Ergonomics, Virtual Environment, Cutting

A New Standing Posture Detector to Enable People with Multiple Disabilities to Control Environmental Stimulation by Changing Their Standing Posture through a Commercial Wii Balance Board

Science.gov (United States)

Shih, Ching-Hsiang; Shih, Ching-Tien; Chiang, Ming-Shan

2010-01-01

This study assessed whether two persons with multiple disabilities would be able to control environmental stimulation using body swing (changing standing posture) and a Wii Balance Board with a newly developed standing posture detection program (i.e. a new software program turns a Wii Balance Board into a precise standing posture detector). The…

Contract portfolio optimization for a gasoline supply chain

Science.gov (United States)

Wang, Shanshan

Major oil companies sell gasoline through three channels of trade: branded (associated with long-term contracts), unbranded (associated with short-term contracts), and spot market. The branded channel provides them with a long-term secured and sustainable demand source, but requires an inflexible long-term commitment with demand and price risks. The unbranded channel provides a medium level of allocation flexibility. The spot market provides them with the greatest allocation flexibility to the changing market conditions, but the spot market's illiquidity mitigates this benefit. In order to sell the product in a profitable and sustainable way, they need an optimal contract portfolio. This dissertation addresses the contract portfolio optimization problem from different perspectives (retrospective view and forward-looking view) at different levels (strategic level, tactical level and operational level). The objective of the retrospective operational model is to develop a financial case to estimate the business value of having a dynamic optimization model and quantify the opportunity values missed in the past. This model proves the financial significance of the problem and provides top management valuable insights into the business. BP has applied the insights and principles gained from this work and implemented the model to the entire Midwest gasoline supply chain to retrospectively review optimization opportunities. The strategic model is the most parsimonious model that captures the essential economic tradeoffs among different contract types, to demonstrate the need for a contract portfolio and what drives the portfolio. We examine the properties of the optimal contract portfolio and provide a comparative statics analysis by changing the model parameters. As the strategic model encapsulates the business problem at the macroscopic level, the tactical model resolves lower level issues. It considers the time dynamics, the information flow and contracting flow. Using

Nuclear Posture Review

Science.gov (United States)

2018-02-01

REVIEW margin for further delay in recapitalizing the physical infrastructure needed to produce strategic materials and components for U.S. nuclear... REVIEW 2018 This page left intentionally blank REVIEW NUCLEAR POSTURE REVIEW FEBRUARY 2018...OFFICE OF THE SECRETARY OF DEFENSE This page left intentionally blank REVIEW CONTENTS SECRETARY’S PREFACE

Unipedal postural stability in nonathletes with core instability after intensive abdominal drawing-in maneuver.

Science.gov (United States)

Lee, Nam G; You, Joshua Sung H; Kim, Tae H; Choi, Bong S

2015-02-01

The exact neuromechanical nature and relative contribution of the abdominal drawing-in maneuver (ADIM) to postural instability warrants further investigation in uninjured and injured populations. To determine the effects of the ADIM on static core and unipedal postural stability in nonathletes with core instability. Controlled laboratory study. University research laboratory. A total of 19 nonathletes (4 women: age = 22.3 ± 1.3 years, height = 164.0 ± 1.7 cm, mass = 56.0 ± 4.6 kg; 15 men: age = 24.6 ± 2.8 years, height = 172.6 ± 4.7 cm, mass = 66.8 ± 7.6 kg) with core instability. Participants received ADIM training with visual feedback 20 minutes each day for 7 days each week over a 2-week period. Core instability was determined using a prone formal test and measured by a pressure biofeedback unit. Unipedal postural stability was determined by measuring the center-of-pressure sway and associated changes in the abdominal muscle-thickness ratios. Electromyographic activity was measured concurrently in the external oblique, erector spinae, gluteus medius, vastus medialis oblique, tibialis anterior, and medial gastrocnemius muscles. All participants initially were unable to complete the formal test. However, after the 2-week ADIM training period, all participants were able to reduce the pressure biofeedback unit by a range of 4 to 10 mm Hg from an initial 70 mm Hg and maintain it at 60 to 66 mm Hg with minimal activation of the external oblique (t(18) = 3.691, P = .002) and erector spinae (t(18) = 2.823, P = .01) muscles. Monitoring of the pressure biofeedback unit and other muscle activations confirmed that the correct muscle contraction defining the ADIM was accomplished. This core stabilization was well maintained in the unipedal-stance position, as evidenced by a decrease in the center-of-pressure sway measures (t(18) range, 3.953-5.775, P < .001), an increased muscle-thickness ratio for the transverse abdominis (t(18) = -2.327, P = .03), and a reduction in

Influência dos exercícios perineais e dos cones vaginais, associados à correção postural, no tratamento da incontinência urinária feminina Influence of perineal exercises and vaginal cones in association with corrective postural exercises, on female urinary incontinence treatment

Directory of Open Access Journals (Sweden)

LM Matheus

2006-12-01

of perineal muscle contraction, via functional evaluation of the pelvic floor (FEPF; quantitative urinary loss, using the pad test; and sensations of dampness and discomfort, via a visual analog scale (VAS. Postural data were collected using the static pelvic test, muscle chain flexibility test and postural evaluation. RESULTS: Comparing the data before and after the intervention, there were statistically significant decreases in urinary loss (p < 0.05 for both groups. There were gains in pelvic floor muscle contraction and significant decreases in the sensation of dampness. The degree of discomfort following the intervention was significantly lower for the group that did perineal exercises. The pelvic static balance was corrected in most of the volunteers and there were gains in muscle chain flexibility. CONCLUSIONS: Static correction of the pelvis by means of postural exercises is an efficient method for female urinary incontinence treatment when associated with perineal muscle training.

Postural control in chronic obstructive pulmonary disease: a systematic review.

Science.gov (United States)

Porto, E F; Castro, A A M; Schmidt, V G S; Rabelo, H M; Kümpel, C; Nascimento, O A; Jardim, J R

2015-01-01

Patients with chronic obstructive pulmonary disease (COPD) fall frequently, although the risk of falls may seem less important than the respiratory consequences of the disease. Nevertheless, falls are associated to increased mortality, decreased independence and physical activity levels, and worsening of quality of life. The aims of this systematic review was to evaluate information in the literature with regard to whether impaired postural control is more prevalent in COPD patients than in healthy age-matched subjects, and to assess the main characteristics these patients present that contribute to impaired postural control. Five databases were searched with no dates or language limits. The MEDLINE, PubMed, EMBASE, Web of Science, and PEDro databases were searched using "balance", "postural control", and "COPD" as keywords. The search strategies were oriented and guided by a health science librarian and were performed on March 27, 2014. The studies included were those that evaluated postural control in COPD patients as their main outcome and scored more than five points on the PEDro scale. Studies supplied by the database search strategy were assessed independently by two blinded researchers. A total of 484 manuscripts were found using the "balance in COPD or postural control in COPD" keywords. Forty-three manuscripts appeared more than once, and 397 did not evaluate postural control in COPD patients as the primary outcome. Thus, only 14 studies had postural control as their primary outcome. Our study examiners found only seven studies that had a PEDro score higher than five points. The examiners' interrater agreement was 76.4%. Six of those studies were accomplished with a control group and one study used their patients as their own controls. The studies were published between 2004 and 2013. Patients with COPD present postural control impairment when compared with age-matched healthy controls. Associated factors contributing to impaired postural control were

Differences in body composition and prevalence for postural ...

African Journals Online (AJOL)

The aim of this study is to compare the prevalence rate for postural deviations and body composition status among two racial groups in South Africa. The sample (n = 216) consisted of 89 African girls and 127 Caucasian girls. Anthropometric (BMI and percentage body fat) and body posture measurements were performed.

Working Posture Analysis Methods and the Effects of Working Posture on Musculoskeletal Disorders

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Hatice Esen

2013-01-01

Full Text Available Musculoskeletal Disorders (MSDs which cause great health problems and social resource consumption are common problems which commonly influence working population. MSDs which is at the top of the list in the sense of health problems, expenses made for these disorders and which has negative influences in the sense of employee labor efficiency, quality of life, physical and social functions results from poor working postures. Observation, analysis of working postures with scientific methods, and making necessary recoveries and arrangements bring important contributions for control of working performance and decrease of MSDs. In this study, risk factors which cause the emergence of MSDs, types and symptoms of disorders are summarized, basic principles to be used in preventing these disorders are presented and scientific methods used in determination of risk factors are classified and presented.

Postural activity monitoring for increasing safety in bomb disposal missions

International Nuclear Information System (INIS)

Brusey, James; Rednic, Ramona; Gaura, Elena I; Kemp, John; Poole, Nigel

2009-01-01

In enclosed suits, such as those worn by explosive ordnance disposal (EOD) experts, evaporative cooling through perspiration is less effective and, particularly in hot environments, uncompensable heat stress (UHS) may occur. Although some suits have cooling systems, their effectiveness during missions is dependent on the operative's posture. In order to properly assess thermal state, temperature-based assessment systems need to take posture into account. This paper builds on previous work for instrumenting EOD suits with regard to temperature monitoring and proposes to also monitor operative posture with MEMS accelerometers. Posture is a key factor in predicting how body temperature will change and is therefore important in providing local or remote warning of the onset of UHS. In this work, the C4.5 decision tree algorithm is used to produce an on-line classifier that can differentiate between nine key postures from current acceleration readings. Additional features that summarize how acceleration is changing over time are used to improve average classification accuracy to around 97.2%. Without such temporal feature extraction, dynamic postures are difficult to classify accurately. Experimental results show that training over a variety of subjects, and in particular, mixing gender, improves results on unseen subjects. The main advantages of the on-line posture classification system described here are that it is accurate, does not require integration of acceleration over time, and is computationally lightweight, allowing it to be easily supported on wearable microprocessors

Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults.

Science.gov (United States)

Furtado, Fabianne; Gonçalves, Bruno da Silva B; Abranches, Isabela Lopes Laguardia; Abrantes, Ana Flávia; Forner-Cordero, Arturo

2016-01-01

The lack of sleep, both in quality and quantity, is an increasing problem in modern society, often related to workload and stress. A number of studies have addressed the effects of acute (total) sleep deprivation on postural control. However, up to date, the effects of chronic sleep deficits, either in quantity or quality, have not been analyzed. Thirty healthy adults participated in the study that consisted of registering activity with a wrist actigraph for more than a week before performing a series of postural control tests. Sleep and circadian rhythm variables were correlated and the sum of activity of the least active 5-h period, L5, a rhythm variable, obtained the greater coefficient value with sleep quality variables (wake after sleep onset WASO and efficiency sleep). Cluster analysis was performed to classify subjects into two groups based on L5 (low and high). The balance tests scores used to asses postural control were measured using Biodex Balance System and were compared between the two groups with different sleep quality. The postural tests were divided into dynamic (platform tilt with eyes open, closed and cursor) and static (clinical test of sensory integration). The results showed that during the tests with eyes closed, the group with worse sleep quality had also worse postural control performance. Lack of vision impairs postural balance more deeply in subjects with chronic sleep inefficiency. Chronic poor sleep quality impairs postural control similarly to total sleep deprivation.

Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults.

Directory of Open Access Journals (Sweden)

Fabianne Furtado

Full Text Available The lack of sleep, both in quality and quantity, is an increasing problem in modern society, often related to workload and stress. A number of studies have addressed the effects of acute (total sleep deprivation on postural control. However, up to date, the effects of chronic sleep deficits, either in quantity or quality, have not been analyzed. Thirty healthy adults participated in the study that consisted of registering activity with a wrist actigraph for more than a week before performing a series of postural control tests. Sleep and circadian rhythm variables were correlated and the sum of activity of the least active 5-h period, L5, a rhythm variable, obtained the greater coefficient value with sleep quality variables (wake after sleep onset WASO and efficiency sleep. Cluster analysis was performed to classify subjects into two groups based on L5 (low and high. The balance tests scores used to asses postural control were measured using Biodex Balance System and were compared between the two groups with different sleep quality. The postural tests were divided into dynamic (platform tilt with eyes open, closed and cursor and static (clinical test of sensory integration. The results showed that during the tests with eyes closed, the group with worse sleep quality had also worse postural control performance. Lack of vision impairs postural balance more deeply in subjects with chronic sleep inefficiency. Chronic poor sleep quality impairs postural control similarly to total sleep deprivation.

Predictors of Postural Stability in Children with ADHD

Science.gov (United States)

Ghanizadeh, Ahmad

2011-01-01

Objective: As children with ADHD who have more inattention problems are more frequently with fine motor problems, it is not clear whether postural balance problems are associated with different subtypes of ADHD. This study investigates the predictors of postural stability in children with ADHD considering the covariant factors of age, gender, and…

Bilateral movements increase sustained extensor force in the paretic arm.

Science.gov (United States)

Kang, Nyeonju; Cauraugh, James H

2018-04-01

Muscle weakness in the extensors poststroke is a common motor impairment. Unfortunately, research is unclear on whether bilateral movements increase extensor force production in the paretic arm. This study investigated sustained force production while stroke individuals maximally extended their wrist and fingers on their paretic arm. Specifically, we determined isometric force production in three conditions: (a) unilateral paretic arm, (b) unilateral nonparetic arm, and (c) bilateral (both arms executing the same movement simultaneously). Seventeen chronic stroke patients produced isometric sustained force by executing wrist and fingers extension in unilateral and bilateral contraction conditions. Mean force, force variability (coefficient of variation), and signal-to-noise ratio were calculated for each contraction condition. Analysis of two-way (Arm × Type of Condition: 2 × 2; Paretic or Nonparetic Arm × Unilateral or Bilateral Conditions) within-subjects ANOVAs revealed that the bilateral condition increased sustained force in the paretic arm, but reduced sustained force in the nonparetic arm. Further, although the paretic arm exhibited more force variability and less signal-to-noise ratio than the nonparetic arm during a unilateral condition, there were no differences when participants simultaneously executed isometric contractions with both arms. Our unique findings indicate that bilateral contractions transiently increased extensor force in the paretic arm. Implications for Rehabilitation Bilateral movements increased isometric wrsit extensor force in paretic arms and redcued force in nonparetic arms versus unilateral movements. Both paretic and nonparetic arms produced similar force variability and signal-to-noise ratio during bilateral movements. Increased sustained force in the paretic arm during the bilateral condition indicates that rehabilitation protocols based on bilateral movements may be beneficial for functional recovery.

Postural control and freezing of gait in Parkinson's disease.

Science.gov (United States)

Schlenstedt, Christian; Muthuraman, Muthuraman; Witt, Karsten; Weisser, Burkhard; Fasano, Alfonso; Deuschl, Günther

2016-03-01

The relationship between freezing of gait (FOG) and postural instability in Parkinson's disease (PD) is unclear. We analyzed the impact of FOG on postural control. 31 PD patients with FOG (PD+FOG), 27 PD patients without FOG (PD-FOG) and 22 healthy control (HC) were assessed in the ON state. Postural control was measured with the Fullerton Advanced Balance (FAB) scale and with center of pressure (COP) analysis during quiet stance and maximal voluntary forward/backward leaning. The groups were balanced concerning age, disease duration and disease severity. PD+FOG performed significantly worse in the FAB scale (21.8 ± 5.8) compared to PD-FOG (25.6 ± 5.0) and HC (34.9 ± 2.4) (mean ± SD, p postural control asymmetry. PD+FOG have reduced postural control compared to PD-FOG and HC. Our results show a relationship between the anterior-posterior COP position during quiet stance and FOG. The COP shift towards posterior in PD+FOG leads to a restricted precondition to generate forward progression during gait initiation. This may contribute to the occurrence of FOG or might be a compensatory strategy to avoid forward falls. Copyright © 2015 Elsevier Ltd. All rights reserved.

Increased dynamic regulation of postural tone through Alexander Technique training.

Science.gov (United States)

Cacciatore, T W; Gurfinkel, V S; Horak, F B; Cordo, P J; Ames, K E

2011-02-01

Gurfinkel and colleagues (2006) recently found that healthy adults dynamically modulate postural muscle tone in the body axis during anti-gravity postural maintenance and that this modulation is inversely correlated with axial stiffness. Our objective in the present study was to investigate whether dynamic modulation of axial postural tone can change through training. We examined whether teachers of the Alexander Technique (AT), who undergo "long-term" (3-year) training, have greater modulation of axial postural tone than matched control subjects. In addition, we performed a longitudinal study on the effect of "short-term" (10-week) AT training on the axial postural tone of individuals with low back pain (LBP), since short term AT training has previously been shown to reduce LBP. Axial postural tone was quantified by measuring the resistance of the neck, trunk and hips to small (±10°), slow (1°/s) torsional rotation during stance. Modulation of tone was determined by the torsional resistance to rotation (peak-to-peak, phase-advance, and variability of torque) and axial muscle activity (EMG). Peak-to-peak torque was lower (∼50%), while phase-advance and cycle-to-cycle variability were enhanced for AT teachers compared to matched control subjects at all levels of the axis. In addition, LBP subjects decreased trunk and hip stiffness following short-term AT training compared to a control intervention. While changes in static levels of postural tone may have contributed to the reduced stiffness observed with the AT, our results suggest that dynamic modulation of postural tone can be enhanced through long-term training in the AT, which may constitute an important direction for therapeutic intervention. Copyright © 2010 Elsevier B.V. All rights reserved.

Postural control in chronic obstructive pulmonary disease: a systematic review

Directory of Open Access Journals (Sweden)

Porto EF

2015-06-01

Full Text Available EF Porto,1,2 AAM Castro,1,3 VGS Schmidt,4 HM Rabelo,4 C Kümpel,2 OA Nascimento,5 JR Jardim5 1Pulmonary Rehabilitation Center, Federal University of São Paulo, 2Adventist University, São Paulo, 3Federal University of Pampa, Rio Grande do Sul, 4Pulmonary Rehabilitation Center, Adventist University, 5Respiratory Diseases, Pulmonary Rehabilitation Center, Federal University of São Paulo, São Paulo, Brazil Abstract: Patients with chronic obstructive pulmonary disease (COPD fall frequently, although the risk of falls may seem less important than the respiratory consequences of the disease. Nevertheless, falls are associated to increased mortality, decreased independence and physical activity levels, and worsening of quality of life. The aims of this systematic review was to evaluate information in the literature with regard to whether impaired postural control is more prevalent in COPD patients than in healthy age-matched subjects, and to assess the main characteristics these patients present that contribute to impaired postural control.Methods: Five databases were searched with no dates or language limits. The MEDLINE, PubMed, EMBASE, Web of Science, and PEDro databases were searched using “balance”, “postural control”, and “COPD” as keywords. The search strategies were oriented and guided by a health science librarian and were performed on March 27, 2014. The studies included were those that evaluated postural control in COPD patients as their main outcome and scored more than five points on the PEDro scale. Studies supplied by the database search strategy were assessed independently by two blinded researchers.Results: A total of 484 manuscripts were found using the “balance in COPD or postural control in COPD” keywords. Forty-three manuscripts appeared more than once, and 397 did not evaluate postural control in COPD patients as the primary outcome. Thus, only 14 studies had postural control as their primary outcome. Our study

Buying results? Contracting for health service delivery in developing countries.

Science.gov (United States)

Loevinsohn, Benjamin; Harding, April

To achieve the health-related Millennium Development Goals, the delivery of health services will need to improve. Contracting with non-state entities, including non-governmental organisations (NGOs), has been proposed as a means for improving health care delivery, and the global experience with such contracts is reviewed here. The ten investigated examples indicate that contracting for the delivery of primary care can be very effective and that improvements can be rapid. These results were achieved in various settings and services. Many of the anticipated difficulties with contracting were either not observed in practice or did not compromise contracting's effectiveness. Seven of the nine cases with sufficient experience (greater than 3 years' elapsed experience) have been sustained and expanded. Provision of a package of basic services by contractors costs between roughly US3 dollars and US6 dollars per head per year in low-income countries. Contracting for health service delivery should be expanded and future efforts must include rigorous evaluations.

MODIFIED PATH METHODOLOGY FOR OBTAINING INTERVAL-SCALED POSTURAL ASSESSMENTS OF FARMWORKERS.

Science.gov (United States)

Garrison, Emma B; Dropkin, Jonathan; Russell, Rebecca; Jenkins, Paul

2018-01-29

Agricultural workers perform tasks that frequently require awkward and extreme postures that are associated with musculoskeletal disorders (MSDs). The PATH (Posture, Activity, Tools, Handling) system currently provides a sound methodology for quantifying workers' exposure to these awkward postures on an ordinal scale of measurement, which places restrictions on the choice of analytic methods. This study reports a modification of the PATH methodology that instead captures these postures as degrees of flexion, an interval-scaled measurement. Rather than making live observations in the field, as in PATH, the postural assessments were performed on photographs using ImageJ photo analysis software. Capturing the postures in photographs permitted more careful measurement of the degrees of flexion. The current PATH methodology requires that the observer in the field be trained in the use of PATH, whereas the single photographer used in this modification requires only sufficient training to maintain the proper camera angle. Ultimately, these interval-scale measurements could be combined with other quantitative measures, such as those produced by electromyograms (EMGs), to provide more sophisticated estimates of future risk for MSDs. Further, these data can provide a baseline from which the effects of interventions designed to reduce hazardous postures can be calculated with greater precision. Copyright© by the American Society of Agricultural Engineers.

Postural stability in young adults with Down syndrome in challenging conditions.

Directory of Open Access Journals (Sweden)

Ewa Bieć

Full Text Available To evaluate postural control and performance in subjects with Down syndrome (SwDS, we measured postural sway (COP in quiet stance in four 20-second tests: with eyes open or closed and on hard or foam surface. Ten SwDS and eleven healthy subjects participated, aged 29.8 (4.8 and 28.4 (3.9, respectively. The time-series recorded with the sampling rate of 100 Hz were used to evaluate postural performance (COP amplitude and mean velocity and strategies (COP frequency, fractal dimension and entropy. There were no intergroup differences in the amplitude except the stance on foam pad with eyes open when SwDS had larger sway. The COP velocity and frequency were larger in SwDS than controls in all trials on foam pad. During stances on the foam pad SwDS increased fractal dimension showing higher complexity of their equilibrium system, while controls decreased sample entropy exhibiting more conscious control of posture in comparison to the stances on hard support surface. This indicated that each group used entirely different adjustments of postural strategies to the somatosensory challenge. It is proposed that the inferior postural control of SwDS results mainly from insufficient experience in dealing with unpredictable postural stimuli and deficit in motor learning.

Assessment of Postural Control in Children with Cerebral Palsy: A Review

Science.gov (United States)

Pavao, Silvia Leticia; dos Santos, Adriana Neves; Woollacott, Marjorie Hines; Rocha, Nelci Adriana Cicuto Ferreira

2013-01-01

This paper aimed to review studies that assessed postural control (PC) in children with cerebral palsy (CP) and describe the methods used to investigate postural control in this population. It also intended to describe the performance of children with CP in postural control. An extensive database search was performed using the keywords: postural…

Controle postural em indivíduos portadores da síndrome de Down: revisão de literatura Postural control in individuals with Down syndrome: a review

Directory of Open Access Journals (Sweden)

Regiane Luz Carvalho

2008-09-01

Full Text Available Este trabalho consistiu numa revisão da literatura sobre controle postural em indivíduos portadores da síndrome de Down, por meio de consulta às bases de dados Medline, Lilacs e Web of Science. Dentre os artigos publicados nos últimos 16 anos, selecionaram-se 30, dos quais 7 focalizam a natureza dos défices no sistema de controle postural, como alterações neurobiológicas e biomecânicas, e 23 enfocam o controle postural no período de desenvolvimento (11 artigos e em adolescentes e adultos (12 artigos portadores da síndrome. Discutem-se os marcos teóricos que conformam a compreensão do desenvolvimento postural e seus défices, bem como as implicações dessa compreensão para a prática da fisioterapia.This is a review of literature on postural control in individuals with the Down syndrome, by searching in Medline, Lilacs and Web of Science data bases. Among articles published in the last 16 years, 30 were selected, of which 7 focus on postural control system deficits, such as neurobiological and biomechanical alterations, and 23 focus postural control development (11 articles and in adolescents and adults (12 articles with the Down syndrome. The theoretic bases for understanding posture control development and deficits are discussed, in view of their implications for physical therapy practice.

Political Market Orientation and Strategic Party Postures in Danish Political Parties

DEFF Research Database (Denmark)

Ormrod, Robert P.; Henneberg, Stephan

2011-01-01

Purpose – This paper investigates the relationship between the strategic postures and political market orientation profile of two Danish parties. Profile stability at the organisational level is used as a control variable. Design/methodology/approach – The strategic political postures of two Danish...... are used to control for organisational stability. Findings – The self-typing study revealed that Party A was perceived to follow a Relationship Builder posture, and Party B a Convinced Ideologist posture. However, both market orientation profiles resembled the organisational structures of a Convinced...... in the political sphere. More specifically it empirically links political market orientation as an issue of political marketing implementation on the one hand, and strategic postures of parties as a strategic issue on the other, following a configuration theory logic. Research limitations...

Chiropractic biophysics technique: a linear algebra approach to posture in chiropractic.

Science.gov (United States)

Harrison, D D; Janik, T J; Harrison, G R; Troyanovich, S; Harrison, D E; Harrison, S O

1996-10-01

This paper discusses linear algebra as applied to human posture in chiropractic, specifically chiropractic biophysics technique (CBP). Rotations, reflections and translations are geometric functions studied in vector spaces in linear algebra. These mathematical functions are termed rigid body transformations and are applied to segmental spinal movement in the literature. Review of the literature indicates that these linear algebra concepts have been used to describe vertebral motion. However, these rigid body movers are presented here as applying to the global postural movements of the head, thoracic cage and pelvis. The unique inverse functions of rotations, reflections and translations provide a theoretical basis for making postural corrections in neutral static resting posture. Chiropractic biophysics technique (CBP) uses these concepts in examination procedures, manual spinal manipulation, instrument assisted spinal manipulation, postural exercises, extension traction and clinical outcome measures.

Postural health in women: the role of physiotherapy.

Science.gov (United States)

Britnell, S J; Cole, J V; Isherwood, L; Sran, M M; Britnell, N; Burgi, S; Candido, G; Watson, L

2005-05-01

To advise obstetric and gynaecology care providers of the physical, psychological, and environmental factors that affect women's posture throughout their lifespan, from adolescence to menopause. To outline the physiotherapy management of obstetrics, osteoporosis, and urinary incontinence in women and to identify recommendations for referral to a physiotherapist. Knowledge of abnormal postures, contributing factors and recommendations for physiotherapy management. MEDLINE, PEDro, and Cochrane Library Search from 1992 to 2003 for English-language articles and references from current textbooks related to posture and women's health conditions that are managed by physiotherapists. The evidence collected was reviewed by the authors and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on the Periodic Health Exam. 1. Pelvic floor muscle training with a physiotherapist is recommended to prevent urinary incontinence during pregnancy and after delivery (I-A). 2. Core stability training with a physiotherapist is recommended to prevent and treat back and pelvic pain during and following pregnancy (I-B). 3. Physiotherapist-prescribed exercises are recommended for women to elicit positive changes in bone mass and to reduce fall and fracture risk (I-A). 4. Pelvic floor muscle training with a physiotherapist is recommended for women with stress urinary incontinence (I-A). The Canadian Physiotherapy Association and Society of Obstetricians and Gynaecologists of Canada have developed this joint policy statement regarding posture in women's health that highlights the physical, psychological, and environmental factors that affect women's posture throughout their lifespan, from adolescence to menopause. This statement outlines the role of physiotherapy in the assessment and treatment of women's posture; outlines the physiotherapy management of obstetrics, osteoporosis, and urinary incontinence; and identifies recommendations for referral to a

Mild hallux valgus angle affects single-limb postural stability in asymptomatic subjects.

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Çınar-Medeni, Özge; Atalay Guzel, Nevin; Basar, Selda

2016-01-01

Single-limb postural stability is a key component of lower extremity functional status. Factors affecting postural stability should be well defined to prevent injuries. The aim of this study was to investigate the effect of the hallux valgus angle on postural stability in asymptomatic subjects. A total of 19 subjects were included in the study. The hallux valgus angle and postural stability were assessed. Participants were assigned to two groups according to whether the hallux valgus angle was pathological or not. A hallux valgus angle greater than 15 degrees was accepted as pathological. The relationship between the hallux valgus angle and postural stability, and the differences in postural stability scores between the two groups were analyzed. Postural stability was assessed with a stabilometer. The test was performed with the eyes open. We found a significant correlation between the hallux valgus angle and mediolateral and overall stability index (r= 0.484, p= 0.036; r = 0.463, p= 0.046 respectively). Subjects with a pathological mild hallux valgus angle had greater stability index scores than normal subjects (phallux valgus angle has negative effects on postural stability as a forefoot deformity. This deformity should be taken into account for injury prevention strategies in pain-free younger adults.

The effect of posture and repetition on urodynamic parameters: A prospective randomized study

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Ho Joon Jeon

2017-01-01

Full Text Available Purpose: To evaluate the effect of posture and repetition of filling cystometry on urodynamic parameters. Materials and Methods: Seventy-one men with benign prostatic hyperplasia participated in a urodynamic study between September 2015 and August 2016 and were randomly assigned to a supine to supine (group SS, n=16, erect to erect (group EE, n=16, supine to erect (group SE, n=19 or erect to supine (group ES, n=20 group. The patients underwent filling cystometry twice. We evaluated the effect of posture and the effect of repetition on filling cystometric parameters. We also evaluated the correlation between overactive bladder (OAB and detrusor overactivity (DO and between maximum voided volume (MVV and maximum cystometric capacity (MCC for each posture and filling cystometry time. Results: There was a decrease in bladder sensation and occurrence of DO, and an increase in bladder compliance and MCC in the supine posture group compared to that in the erect posture group. A more significant decrease in bladder sensation and occurrence of DO as well as an increase in MCC was seen during the second filling cystometry than the first one. The supine posture during first filling cystometry showed a better correlation between OAB and DO and between MVV and MCC than erect posture. Conclusions: There were clear effects of posture and filling cystometry repetition on urodynamic parameters. The supine posture and repeated filling cystometry caused the bladder to be less sensitive and less overactive. The supine posture showed a better correlation to OAB symptoms than erect posture during first filling cystometry.

Evaluation of body posture in nursing students

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Marília Fernandes Andrade

2017-08-01

Full Text Available Abstract OBJECTIVE To investigate the body posture of nursing students before and after clinical practice. METHOD The study was developed in two stages. Initially the body posture of students of the 2nd, 4th, 6th, and 8th periods were assessed through photogrammetry. All images were analyzed in a random and masked manner with CorporisPro® 3.1.3 software. Three evaluations were performed for each angle and then the mean value was calculated. Two years later, when the 4th period students had developed their clinical internships, their body posture was again evaluated. RESULTS The total sample consisted of 112 students. Comparison of their posture with the normality pattern showed that all the angles presented significant differences (p< 0.00, except for the angle of the Thales triangle. Reassessment of these students evidenced significant differences in the angles of the acromioclavicular joint (p=0.03, knee flexion (p< 0.00 and in the tibiotarsal angle (p< 0.00. CONCLUSION All the students presented alterations when compared to the normality values. The segments that presented significant differences between before and after practice were the acromioclavicular angle, knee flexion, and tibiotarsal angle; the latter two were in the rolling position.

Is there a relationship between head posture and craniomandibular pain?

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Visscher, C M; De Boer, W; Lobbezoo, F; Habets, L L M H; Naeije, M

2002-11-01

An often-suggested factor in the aetiology of craniomandibular disorders (CMD) is an anteroposition of the head. However, the results of clinical studies to the relationship between CMD and head posture are contradictory. Therefore, the first aim of this study was to determine differences in head posture between well-defined CMD pain patients with or without a painful cervical spine disorder and healthy controls. The second aim was to determine differences in head posture between myogenous and arthrogenous CMD pain patients and controls. Two hundred and fifty persons entered the study. From each person, a standardized oral history was taken and blind physical examinations of the masticatory system and of the neck were performed. The participants were only included into one of the subgroups when the presence or absence of their symptoms was confirmed by the results of the physical examination. Head posture was quantified using lateral photographs and a lateral radiograph of the head and the cervical spine. After correction for age and gender effects, no difference in head posture was found between any of the patient and non-patient groups (P > 0.27). Therefore, this study does not support the suggestion that painful craniomandibular disorders, with or without a painful cervical spine disorder, are related to head posture.

Posture and low back pain during pregnancy - 3D study.

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Glinkowski, Wojciech M; Tomasik, Paweł; Walesiak, Katarzyna; Głuszak, Michał; Krawczak, Karolina; Michoński, Jakub; Czyżewska, Anna; Żukowska, Agnieszka; Sitnik, Robert; Wielgoś, Mirosław

2016-01-01

Back pain is a common complaint of pregnant women. The posture, curvatures of the spine and the center of gravity changes are considered as the mechanisms leading to pain. The study aimed to assess spinal curvatures and static postural characteristics with three-dimensional surface topography and search for relationships with the occurrence of back pain complaints among pregnant women. The study was conducted from December 2012 to February 2014. Patients referred from University Clinic of Gynecology and Obstetrics were examined outpatient at the Posture Study Unit of Department of Orthopaedics and Traumatology. Sixty-five women at 4-39 weeks of pregnancy were assessed and surveyed with Oswestry Disability Index; posture was evaluated using surface topography. The study confirmed that difficulties in sitting and standing are significant in the third trimester of the pregnancy. The overall tendency for significant lumbar curvature changes in pregnant women was not confirmed. Major changes in sagittal trunk inclination in relation to the plumb line were not observed in the study group. The issue regarding how the pregnancy causes changes in spinal curvature and posture remains open for further studies. Presented method of 3D surface topography can reveal postural changes, but that requires several exams of each subject and strict follow-up of the series of cases.

FATIGUE AND FAULTY POSTURE CONNECTION AMONG CHILDREN, DIAGNOSED WITH DYSARTHRIA

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Andrejeva Julija

2015-08-01

Full Text Available Purpose : To analyze spastic dysarthria form in children population dependency of fatigue and faulty posture relationship. Methods: Research performed with the permission of the bioethics committee (RE-BK-063. The Dutch Fatigue Scale (DUFS. Posture in standing was assessed by Hoeger and Kendall. Research subjects n=40. n=20 children diagnosed with spastic dysarthria and n=20 of children without dysarthria. Their age was 10±2.1years. Boys were n=20 and girls - n=20.Results were statistically significant at p<0.05. Microsoft Office 2013, Excel package were used to count a research results. Results: For children with dysarthria fatigue level is more significant that for children without dysarthria; results were statistically significant, p<0.05. Posture disorder for children with dysarthria was statistically significant higher than among children without dysarthria, p<0.05. Conclusions: For children with dysarthria fatigue level is higher than for healthy children, thus for the girls fatigue level is higher than for the boys. Spastic form dysarthria has an impact to a child posture, by creating a direct dependency between posture deformation and skeletal muscle system disease, which decreases muscle power and increasing fatigue for a child. To correct faulty posture thus to decrease fatigue the tight collaboration needed between rehabilitation team members.

Fatigue and faulty posture connection among children, diagnosed with dysarthria

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Julija Andrejeva

2015-08-01

Full Text Available Purpose : To analyze spastic dysarthria form in children population dependency of fatigue and faulty posture relationship. Methods: Research performed with the permission of the bioethics committee (RE-BK-063. The Dutch Fatigue Scale (DUFS. Posture in standing was assessed by Hoeger and Kendall. Research subjects n=40. n=20 children diagnosed with spastic dysarthria and n=20 of children without dysarthria. Their age was 10±2.1years. Boys were n=20 and girls - n=20.Results were statistically significant at p<0.05. Microsoft Office 2013, Excel package were used to count a research results. Results: For children with dysarthria fatigue level is more significant that for children without dysarthria; results were statistically significant, p<0.05. Posture disorder for children with dysarthria was statistically significant higher than among children without dysarthria, p<0.05. Conclusions: For children with dysarthria fatigue level is higher than for healthy children, thus for the girls fatigue level is higher than for the boys. Spastic form dysarthria has an impact to a child posture, by creating a direct dependency between posture deformation and skeletal muscle system disease, which decreases muscle power and increasing fatigue for a child. To correct faulty posture thus to decrease fatigue the tight collaboration needed between rehabilitation team members.

Enhancing creativity: Proper body posture meets proper emotion.

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Hao, Ning; Xue, Hua; Yuan, Huan; Wang, Qing; Runco, Mark A

2017-02-01

This study tested whether compatibility or incompatibility between body posture and emotion was beneficial for creativity. In Study 1, participants were asked to solve the Alternative Uses Task (AUT) problems when performing open or closed body posture in positive or negative emotional state respectively. The results showed that originality of AUT performance was higher in the compatible conditions (i.e., open-positive and closed-negative) than in the incompatible conditions (i.e., closed-positive and open-negative). In Study 2, the compatibility effect was replicated in both the AUT and the Realistic Presented Problem test (i.e., RPP). Moreover, it was revealed that participants exhibited the highest associative flexibility in the open-positive condition, and the highest persistence in the closed-negative condition. These findings indicate that compatibility between body posture and emotion is beneficial for creativity. This may be because when the implicit emotions elicited by body posture match explicit emotions, the effects of emotions on creativity are enhanced, therefore promoting creativity through the flexibility or the persistence pathway respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Suboptimal Muscle Synergy Activation Patterns Generalize their Motor Function across Postures.

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Sohn, M Hongchul; Ting, Lena H

2016-01-01

We used a musculoskeletal model to investigate the possible biomechanical and neural bases of using consistent muscle synergy patterns to produce functional motor outputs across different biomechanical conditions, which we define as generalizability. Experimental studies in cats demonstrate that the same muscle synergies are used during reactive postural responses at widely varying configurations, producing similarly-oriented endpoint force vectors with respect to the limb axis. However, whether generalizability across postures arises due to similar biomechanical properties or to neural selection of a particular muscle activation pattern has not been explicitly tested. Here, we used a detailed cat hindlimb model to explore the set of feasible muscle activation patterns that produce experimental synergy force vectors at a target posture, and tested their generalizability by applying them to different test postures. We used three methods to select candidate muscle activation patterns: (1) randomly-selected feasible muscle activation patterns, (2) optimal muscle activation patterns minimizing muscle effort at a given posture, and (3) generalizable muscle activation patterns that explicitly minimized deviations from experimentally-identified synergy force vectors across all postures. Generalizability was measured by the deviation between the simulated force direction of the candidate muscle activation pattern and the experimental synergy force vectors at the test postures. Force angle deviations were the greatest for the randomly selected feasible muscle activation patterns (e.g., >100°), intermediate for effort-wise optimal muscle activation patterns (e.g., ~20°), and smallest for generalizable muscle activation patterns (e.g., synergy force vector was reduced by ~45% when generalizability requirements were imposed. Muscles recruited in the generalizable muscle activation patterns had less sensitive torque-producing characteristics to changes in postures. We

The Control of Posture in Newly Standing Infants is Task Dependent

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Claxton, Laura J.; Melzer, Dawn K.; Ryu, Joong Hyun; Haddad, Jeffrey M.

2012-01-01

The postural sway patterns of newly standing infants were compared under two conditions: standing while holding a toy and standing while not holding a toy. Infants exhibited a lower magnitude of postural sway and more complex sway patterns when holding the toy. These changes suggest that infants adapt postural sway in a manner that facilitates…

Aging causes a reorganization of cortical and spinal control of posture

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Selma ePapegaaij

2014-03-01

Full Text Available Classical studies in animal preparations suggest a strong role for spinal control of posture. In young adults it is now established that the cerebral cortex contributes to postural control of unperturbed and perturbed standing. The age-related degeneration and accompanying functional changes in the brain, reported so far mainly in conjunction with simple manual motor tasks, may also affect the mechanisms that control complex motor tasks involving posture. This review outlines the age-related structural and functional changes at spinal and cortical levels and provides a mechanistic analysis of how such changes may be linked to the behaviorally manifest postural deficits in old adults. The emerging picture is that the age-related reorganization in motor control during voluntary tasks, characterized by differential modulation of spinal reflexes, greater cortical activation and cortical disinhibition, is also present during postural tasks. We discuss the possibility that this reorganization underlies the increased coactivation and dual task interference reported in elderly. Finally, we propose a model for future studies to unravel the structure-function-behavior relations in postural control and aging.

CONCEPTUAL DELIMITATIONS ON SUSTAINABLE DEVELOPMENT

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Ienciu Ionel-Alin

2013-07-01

Full Text Available Sustainable development is a model for resource use meant to satisfy human needs, without polluting the environment, so that these needs can be satisfied not only in the present, but in the future as well. It is a concept of nowadays with no generally accepted definition, placing environment first and foremost, aiming at implementing the environmental policies in all structures and at all economic levels. Within the present study we have aimed at creating a conceptual delimitation on sustainable development, sustainability and socialresponsibility, concepts of present interest, that tend to become a mystery for the academic community and practitioners by their variety and complexity of approaches. During our scientific endeavor we believe that social responsibility is the foundation of sustainable development. Sustainable development is a concept used especially at macro-economic level, while social responsibility is used at entity level and incorporates the economic, environmental and social dimension, which has a voluntary character and tries to respond to the information needs of the society and other stakeholders. Sustainability at the entity\\'s level is the goal or final objective of sustainable development – satisfaction of present needs without compromising the possibility for future generations to satisfy their own needs, while social responsibility is an intermediate phase of sustainability wherein entities try to balance the economic, social and environmental dimension. Thus, we can state we include ourselves within social corporatism, slightly close to social institutionalism, which is characteristic to developed countries, giving a particular importance to social contract and relations between entity and society. We believe that in Romania, a POSDRU funded project should be regarded as a legal person with social values, which must be based on sustainable development and to promote, besides legal liability of automatically deriving

Effects of Dyslexia on Postural Control in Adults

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Patel, M.; Magnusson, M.; Lush, D.; Gomez, S.; Fransson, P. A.

2010-01-01

Dyslexia has been shown to affect postural control. The aim of the present study was to investigate the difference in postural stability measured as torque variance in an adult dyslexic group (n=14, determined using the Adult Dyslexia Checklist (ADCL) and nonsense word repetition test) and an adult non-dyslexic group (n=39) on a firm surface and…

Are Hypometric Anticipatory Postural Adjustments Contributing to Freezing of Gait in Parkinson’s Disease?

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Christian Schlenstedt

2018-02-01

Full Text Available Introduction: This study aims at investigating whether impaired anticipatory postural adjustments (APA during gait initiation contribute to the occurrence of freezing of gait (FOG or whether altered APAs compensate for FOG in Parkinson’s disease (PD.Methods: Gait initiation after 30 s quiet stance was analyzed without and with a cognitive dual task (DT in 33 PD subjects with FOG (PD+FOG, 30 PD subjects without FOG (PD-FOG, and 32 healthy controls (HC. APAs were characterized with inertial sensors and muscle activity of the tensor fasciae latae (TFL, gastrocnemius, and tibialis anterior was captured with electromyography recordings. Nine trials (of 190 were associated with start hesitation/FOG and analyzed separately.Results: PD+FOG and PD-FOG did not differ in disease duration, disease severity, age, or gender. PD+FOG had significantly smaller medio-lateral (ML and anterio-posterior APAs compared to PD-FOG (DT, p < 0.05. PD+FOG had more co-contraction of left and right TFL during APAs compared to PD-FOG (p < 0.01. Within the PD+FOG, the ML size of APA (DT was positively correlated with the severity of FOG history (NFOG-Q, with larger APAs associated with worse FOG (rho = 0.477, p = 0.025. ML APAs were larger during trials with observed FOG compared to trials of PD+FOG without FOG.Conclusions: People with PD who have a history of FOG have smaller ML APAs (weight shifting during gait initiation compared to PD-FOG and HC. However, start hesitation (FOG is not caused by an inability to sufficiently displace the center of mass toward the stance leg because APAs were larger during trials with observed FOG. We speculate that reducing the acceleration of the body center of mass with hip abductor co-contraction for APAs might be a compensatory strategy in PD+FOG, to address postural control deficits and enable step initiation.

Electromyography of the thigh muscles during lifting tasks in kneeling and squatting postures

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Gallagher, S.; Pollard, J.; Porter, W.L. [NIOSH, Pittsburgh, PA (United States). Pittsburgh Research Laboratory

2011-07-01

Underground coal miners who work in low-seam mines frequently handle materials in kneeling or squatting postures. To assess quadriceps and hamstring muscle demands in these postures, nine participants performed lateral load transfers in kneeling and squatting postures, during which electromyographic (EMG) data were collected. EMG activity was obtained at five points throughout the transfer for three quadriceps muscles and two hamstring muscles from each thigh. ANOVA results indicated that EMG data for nine of 10 thigh muscles were affected by an interaction between posture and angular position of the load lifted (p <0.001). Muscles of the right thigh were most active during the lifting portion of the task (lifting a block from the participant's right) and activity decreased as the block was transferred to the left. Left thigh muscles showed the opposite pattern. EMG activity for the majority of thigh muscles was affected by the size of the base of support provided by different postures, with lower EMG activity observed with a larger base of support and increased activity in postures where base of support was reduced (p<0.05). Thigh EMG activity was lowest in postures with fully flexed knees, which may explain worker preference for this posture. However, such postures are also associated with increased risk of meniscal damage.

Time-of-Day Influences on Static and Dynamic Postural Control

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Gribble, Phillip A; Tucker, W. Steven; White, Paul A

2007-01-01

Context: Assessment of postural control is used extensively in clinical and research applications. Time of day affects aspects of physical performance, but whether it also affects postural control is unknown.

Effect of intervention on development of hip posture in very preterm babies.

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Downs, J A; Edwards, A D; McCormick, D C; Roth, S C; Stewart, A L

1991-01-01

Preterm babies are physiologically hypotonic, which causes their posture to be flattened when lying in the prone position. This flattened posture may persist beyond term. In a prospective, randomised, controlled, double blind trial of postural support carried out on 45 babies born at less than 33 weeks of gestation, we showed that infants positioned with specific hip support during the period of intensive care had significantly fewer features of flattened posture at the age equivalent to term.

Usefulness of posture training for patients with temporomandibular disorders.

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Wright, E F; Domenech, M A; Fischer, J R

2000-02-01

Many practitioners have found that posture training has a positive impact on temporomandibular, or TMD, symptoms. The authors conducted a study to evaluate its effectiveness. Sixty patients with TMD and a primary muscle disorder were randomized into two groups: one group received posture training and TMD self-management instructions while the control group received TMD self-management instructions only. Four weeks after the study began, the authors reexamined the subjects for changes in symptoms, pain-free opening and pressure algometer pain thresholds. In addition, pretreatment and posttreatment posture measurements were recorded for subjects in the treatment group. Statistically significant improvement was demonstrated by the modified symptom severity index, maximum pain-free opening and pressure algometer threshold measurements, as well as by the subjects' perceived TMD and neck symptoms. Subjects in the treatment group reported having experienced a mean reduction in TMD and neck symptoms of 41.9 and 38.2 percent, respectively, while subjects in the control group reported a mean reduction in these symptoms of 8.1 and 9.3 percent. Within the treatment group, the authors found significant correlations between improvements in TMD symptoms and improvements in neck symptoms (P head and shoulder posture measurements at the outset of treatment (P Posture training and TMD self-management instructions are significantly more effective than TMD self-management instructions alone for patients with TMD who have a primary muscle disorder. Patients with TMD who hold their heads farther forward relative to the shoulders have a high probability of experiencing symptom improvement as a result of posture training and being provided with selfmanagement instructions.

Prevalence of incorrect body posture in children and adolescents with overweight and obesity.

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Maciałczyk-Paprocka, Katarzyna; Stawińska-Witoszyńska, Barbara; Kotwicki, Tomasz; Sowińska, Anna; Krzyżaniak, Alicja; Walkowiak, Jarosław; Krzywińska-Wiewiorowska, Małgorzata

2017-05-01

The ever increasing epidemics of overweight and obesity in school children may be one of the reasons of the growing numbers of children with incorrect body posture. The purpose of the study was the assessment of the prevalence of incorrect body posture in children and adolescents with overweight and obesity in Poznań, Poland. The population subject to study consisted of 2732 boys and girls aged 3-18 with obesity, overweight, and standard body mass. The assessment of body mass was performed based on BMI, adopting Cole's cutoff values. The evaluation of body posture was performed according to the postural error chart based on criteria complied by professor Dega. The prevalence rates of postural errors were significantly higher among children and adolescents with overweight and obesity than among the group with standard body mass. In the overweight group, it amounted to 69.2% and in the obese group to 78.6%.  The most common postural deviations in obese children and adolescents were valgus knees and flat feet. Overweight and obesity in children and adolescents, predisposing to higher incidence of some types of postural errors, call for prevention programs addressing both health problems. What is Known: • The increase in the prevalence of overweight and obesity among children and adolescents has drawn attention to additional health complications which may occur in this population such as occurrence of incorrect body posture. What is New: • The modified chart of postural errors proved to be an effective tool in the assessment of incorrect body posture. • This chart may be used in the assessment of posture during screening tests and prevention actions at school.

SHOULDER EXTERNAL ROTATOR STRENGTH IN RESPONSE TO VARIOUS SITTING POSTURES: A CONTROLLED LABORATORY STUDY.

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Pheasant, Steven; Haydt, Richard; Gottstein, Thomas; Grasso, Anthony; Lombard, Nicholas; Stone, Brandon

2018-02-01

The forward head rounded shoulder (FHRS) sitting posture has been associated with decreased shoulder complex muscle strength and function. Upon clinical observation, the adverse effects of the FHRS sitting posture on shoulder complex isometric muscle strength is also present when testing controls for scapular position. The purpose of the study was to assess the effect of various sitting postures on shoulder external rotator muscle isometric strength when the strength testing controls for scapular position. A cohort study, with subjects serving as their own controls. One hundred subjects ages 20-26 participated in the study. Each subject was placed in a neutral cervical sitting (NCS) posture which was maintained for five minutes after which the strength of the dominant shoulder external rotators was immediately tested with the glenohumeral joint in the neutral position using a Micro-FET3 Hand Held Muscle Testing Dynamometer (HHMTD). Each subject was returned to the NCS posture for subsequent external rotator strength testing after five minutes in a FHRS sitting posture, five additional minutes in the NCS posture and five minutes in a retracted cervical sitting (RCS) posture resulting in each subjects' external rotator strength being tested on four occasions. Subjects were randomized for order between the FHRS and RCS postures. Mean strength values for each condition were normalized to the mean strength value for the 1 st NCS condition for each subject. A statistically significant decline in shoulder external rotator strength following the FHRS sitting posture occurred compared to the appropriate postural conditions (pexternal rotator strength following five minutes in the FHRS sitting posture. The average percentage of strength decline in those with greater than a 10% reduction in external rotator strength was 19%. Sixty-four percent of the subjects experienced less than a 10% decline in shoulder external rotator strength in response to the FHRS sitting posture

Relationships between Malocclusion, Body Posture, and Nasopharyngeal Pathology in Pre-Orthodontic Children.

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Šidlauskienė, Monika; Smailienė, Dalia; Lopatienė, Kristina; Čekanauskas, Emilis; Pribuišienė, Rūta; Šidlauskas, Mantas

2015-06-18

Malocclusion, body posture, and breathing pattern may be correlated, but this issue is still controversial. The aim of the study was to examine the relationship between the type of malocclusion, body posture, and nasopharyngeal obstruction in children aged 7-14 years. The study group comprised 94 patients aged 7-14 years (mean±SD: 11.9±2.1 years); 44 (46.8%) males and 50 (53.2%) females. All patients passed an examination performed by the same orthodontist (study model and cephalometric radiograph analysis), orthopedic surgeon (body posture examined from the front, side, and back), and otorhinolaryngologist (anterior and posterior rhinoscopy and pharyngoscopy) in a blind manner. Postural disorders were observed in 72 (76.6%) patients. Hypertrophy of the adenoids was diagnosed in 54 (57.4%) patients, hypertrophy of the tonsils in 85 (90.3%), nasal septum deviation in 51 (54.3%), and allergic rhinitis in 19 (20.2%) patients. There was a statistically significant correlation between presence of kyphotic posture and a reduction in the SNB angle, representing sagittal position of the mandible. Also, there was a statistically significant association between kyphotic posture and nasopharyngeal obstruction (54.1% of patients with nasopharyngeal obstruction were kyphotic, compared with 25% of patients with no nasopharyngeal obstruction; p=0.02). Kyphotic posture and reduced SNB angle were more common among males. We concluded that: 1) there was a significant association between the sagittal position of the mandible (SNB angle) and a kyphotic posture; 2) kyphotic posture was significantly more common among patients with nasopharyngeal obstruction.

Postural Evaluation of Vertebral Column in Children and Teenagers with Hearing Loss

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Toscano, Carla Fabiana da Silva

2011-04-01

Full Text Available Introduction: Posture is determined by the performance of the visual, somatosensory and vestibular systems. Children with hearing loss can present problems in their posture or postural control, enabling postural deviations and alterations to appear in their vertebral column, possibly provoked by a hypoactivity of the vestibular system as a result of deafness. Objective: To evaluate the posture of the vertebral column in children and teenagers with hearing loss at school age, taking into consideration the sample gender and age. Method: A descriptive and prospective study was performed at both Duque de Caxias School and Rotary Rehabilitation and Special Education Center in Caruaru - Pernambuco. 44 students aged between 7-17 years old, out of whom 22 were female and 22 were male, with hearing loss were evaluated. The study was developed by way of a postural evaluation, using a symmetrograph, marking specific anatomical points with stickers placed over polystyrene balls and fixed with double-sided adhesive tape. Results:The results showed that all of the individuals evaluated in this study presented some kind of postural alteration in their vertebral column. Scoliosis was the most observed alteration among the students (84.1%, followed by thoracic hyperkyphosis (68.2%. Conclusion: It has been concluded that children and teenagers with hearing loss are exposed to postural alteration in their vertebral column. Such a condition can be associated with a number of factors comprising unfavorable ergonomics of the school environment, bad postural habits and impairment of the vestibular system by virtue of the hearing loss.

The study of postural workload in assembly of furniture upholstery

OpenAIRE

Marek Lasota Andrzej; Hankiewicz Krzysztof

2017-01-01

The productivity of the workers is affected by the Work-related Musculoskeletal Disorders (WRMSDs) which common cause of health problems, sick leave and it can result in decreased quality of work and increased absenteeism. The objective of this study is to evaluate and investigate the postural workload of sewing machine operators in the assembly of upholstery in furniture factory by using the Ovako Working Posture Analysing System (OWAS) with sampling. The results indicated that posture code ...

The final common pathway in postural control - Developmental perspective

NARCIS (Netherlands)

Kernell, D

A brief review is given concerning postural specialisations among mammalian muscle fibres and motor units. Most skeletal muscles contain a mixture of fibres with different characteristics, and their slow-twitch (S) units are well-known to possess properties suitable for postural tasks: they are

Textile sustainability: reuse of clean waste from the textile and apparel industry

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Broega, A. C.; Jordão, C.; Martins, S. B.

2017-10-01

Today societies are already experiencing changes in their production systems and even consumption in order to guarantee the survival and well-being of future generations. This fact emerges from the need to adopt a more sustainable posture in both people’s daily lives and productive systems. Within this context, textile sustainability emerges as the object of study of this work whose aim is to analyse which sustainability dimensions are being prioritized by the clean waste management systems of the textile and garment industries. This article aims to analyse solutions that are being proposed by sustainable creative business models in the reuse of discarded fabrics by the textile industry. Search also through a qualitative research by a case study (the Reuse Fabric Bank) understand the benefits generated by the re-use in environmental, economic, social and ways to add value.

Postural stability and ankle sprain history in athletes compared to uninjured controls

NARCIS (Netherlands)

Huurnink, A.; Fransz, D.P.; Kingma, I.; Verhagen, E.A.L.M.; van Dieen, J.H.

2014-01-01

Background Diminished postural stability is a risk factor for ankle sprain occurrence and ankle sprains result in impaired postural stability. To date, ankle sprain history has not been taken into account as a determinant of postural stability, while it could possibly specify subgroups of interest.

Postural stability in patients with knee osteoarthritis: comparison with controls and evaluation of relationships between postural stability scores and International Classification of Functioning, Disability and Health components.

Science.gov (United States)

Hsieh, Ru-Lan; Lee, Wen-Chung; Lo, Min-Tzu; Liao, Wei-Cheng

2013-02-01

To assess the differences in postural stability between patients with knee osteoarthritis and controls without knee osteoarthritis, and to evaluate possible relations between postural stability scores and International Classification of Functioning, Disability and Health (ICF) components. An age-matched, case-controlled trial with a cross-sectional design. A teaching hospital. Patients with knee osteoarthritis (n=73) and age-matched controls (n=60). Data on patients' postural stability and additional health-related variables were collected using various instruments. These included the Hospital Anxiety and Depression Scale, the Multidimensional Fatigue Inventory, the World Health Organization Quality of Life Brief Version, the physical function test (chair-rising time), the Chinese version of the Western Ontario and McMaster Universities Osteoarthritis Index, the Chinese version of the Knee Injury and Osteoarthritis Outcome Score, and the Biodex Stability System. A comparison of postural stability in patients with knee osteoarthritis versus that of controls was performed. The relation between postural stability scores for patients with knee osteoarthritis and ICF components was evaluated. Pearson correlation tests were used to determine the variables that correlated with postural stability among these patients. Patients with knee osteoarthritis displayed lower overall postural stability than controls (scores of 0.7 vs. 0.5, P=.006) and scored lower on the environmental domain of the World Health Organization Quality of Life Brief Version (62.2 vs 66.8, P=.014). For patients with knee osteoarthritis, postural stability was weakly associated with the ICF components of body functions and structures, including pain (r=.33-.34, P=.004), physical fatigue (r=.28, P=.016), and reduced motivation (r=.30, P=.011). Weak to moderate associations between postural stability and the ICF components of activities and participation were found; the relevant ICF variables included

[Research on respiration course of human at different postures by electrical impedance tomography].

Science.gov (United States)

Chen, Xiaoyan; Wu, Jun; Wang, Huaxiang; Li, Da

2010-10-01

In this paper, the respiration courses of human at different postures are reconstructed by electrical impedance tomography (EIT). Conjugate gradient least squares (CGLS) algorithm is applied to reconstruct the resistivity distribution during respiration courses, and the EIT images taken from human at flat lying, left lying, right lying, sitting and prone postures are reconstructed and compared. The relative changes of the resistivity in region of interest (ROI) are analyzed to evidence the influences caused by different postures. Results show that the changes in postures are the most influential factors for the reconstructions, and the EIT images vary with the postures. In human at flat-lying posture, the left and right lungs have larger pulmonary ventilation volume simultaneously, and the EIT-measured data are of lower variability.

Analisis ergonomi postur kerja operator pada proses pembuatan batako

Directory of Open Access Journals (Sweden)

Regina Anggraini

2017-03-01

Full Text Available Abstrak: Proses pembuatan batako merupakan salah satu pekerjaan yang membutuhkan penanganan material secara manual,sehingga tenaga fisik pekerja diperlukan meskipun mesin bantu cetak sudah tersedia. Berdasarkan pengamatan dilapangandiketahui bahwa seluruh aktivitas pembuatan batako banyak membutuhkan tenaga fisik. Pekerjaan membuat batako dapatdibagi menjadi beberapa elemen kerja dan setiap elemen kerja memberikan postur kerja yang bervariasi. Hasil analisis posturkerja dengan menggunakan REBA menunjukkan pekerja pada proses pemindahan batako basah memiliki nilai 11 dengan levelrisiko sangat tinggi. Perbaikan dilakukan dengan menambahkan kursi pekerja dan berhasil menurunkan skor REBA menjadi 5.Kata Kunci: Postur kerja, REBA Abstract: Brick-making process is one of those jobs that require manual materials handling, so that the physical exertion of workersneeded though a production machine is already available. Based on observations in the field note that the entire activity ofbrick-making requires a lot of physical exertion. Brick-making can be divided into several working elements and each element ofthe work provides a varied work posture. The results of the analysis work posture using REBA showed workers in the processof moving the wet concrete blocks have a value of 11 with a very high risk level. Improvement of working conditions by adding aseat for workers reduce the REBA score to 5 .Keywords: Work Posture , REBA

The study of postural workload in assembly of furniture upholstery

Directory of Open Access Journals (Sweden)

Marek Lasota Andrzej

2017-01-01

Full Text Available The productivity of the workers is affected by the Work-related Musculoskeletal Disorders (WRMSDs which common cause of health problems, sick leave and it can result in decreased quality of work and increased absenteeism. The objective of this study is to evaluate and investigate the postural workload of sewing machine operators in the assembly of upholstery in furniture factory by using the Ovako Working Posture Analysing System (OWAS with sampling. The results indicated that posture code 2111 (back code: 2 – bent forward; arms code: 1 – both below the shoulder joint; legs code: 1 – sitting position; load code: – 1 less than 10 kg was the most common working posture rating 38.1%; 63.9% of positions displayed non-neutral back postures and 52% received harmful action categories. The performed assembly tasks have an influence on harmless and harmful action categories. This study is crucial on assembly, and in the future work allows develop a framework for assessment the physical risk of WRMSDs in assembly.

Relationship between antigravity control and postural control in young children.

Science.gov (United States)

Sellers, J S

1988-04-01

The purposes of this study were 1) to determine the relationship between antigravity control (supine flexion and prone extension) and postural control (static and dynamic balance), 2) to determine the quality of antigravity and postural control, and 3) to determine whether sex and ethnic group differences correlate with differences in antigravity control and postural control in young children. I tested 107 black, Hispanic, and Caucasian children in a Head Start program, with a mean age of 61 months. The study results showed significant relationships between antigravity control and postural control. Subjects' supine flexion performance was significantly related to the quantity and quality of their static and dynamic balance performance, whereas prone extension performance was related only to the quality of dynamic balance performance. Quality scale measurements (r = .90) indicated that the children in this study had not yet developed full antigravity or postural control. The study results revealed differences between sexes in the quality of static balance and prone extension performance and ethnic differences in static balance, dynamic balance, and prone extension performance.

INFLUENCE OF INJURY ON DYNAMIC POSTURAL CONTROL IN RUNNERS.

Science.gov (United States)

Meardon, Stacey; Klusendorf, Anna; Kernozek, Thomas

2016-06-01

Injury has been linked with altered postural control in active populations. The association between running injury and dynamic postural control has not been examined. The purpose of this study was to examine dynamic postural control in injured and uninjured runners using the Star Excursion Balance Test (SEBT), Time to Stabilization (TTS) of ground reaction forces following a single-leg landing, and postural stability indices reflecting the fluctuations in GRFs during single-leg landing and stabilization tasks (forward and lateral hop). It was hypothesized that dynamic postural control differences would exist between runners with a history of injury that interrupted training for ≥7 days (INJ) when compared to runners without injury (CON). Case-control study. Twenty-two INJ (14 F, 8 M; 23.7 ± 2.1 y; 22.3 ± 2.8 kg/m2; 29.5 ± 16.3 mi/wk) currently running > 50% pre-injury mileage without pain were compared with twenty-two matched CON (14F, 8M; 22.7 ± 1.2 y; 22.7 ± 2.7 kg/m2; 31.2 ± 19.6 mi/wk). INJ group was stratified by site of injury into two groups (Hip/Thigh/Knee and Lower Leg/Ankle/Foot) for secondary analysis. Leg length-normalized anterior, posterolateral, and posteromedial reach distances on the SEBT, medial/lateral and anterior/posterior ground reaction force TTS, directional postural stability indices, and a composite dynamic postural stability index (DPSI), were assessed using mixed model ANOVA (α=0.05) and effect sizes (d). No group X direction interaction or group differences were observed for the SEBT (p=0.51, 0.71) or TTS (p=0.83, 0.72) measures. A group X direction interaction was found for postural stability indices during the forward landing task (ppostural stability index (VPSI) (p=0.01 for both, d=0.80, 0.95) and DPSI (p=0.01, 0.02, d=0.75, 0.93) when compared to CON suggesting impaired balance control. A group X direction interaction was also found for postural stability indices during the lateral landing

Effect of absence of vision on posture

OpenAIRE

Alotaibi, Abdullah Z.; Alghadir, Ahmad; Iqbal, Zaheen A.; Anwer, Shahnawaz

2016-01-01

[Purpose] The visual system is one of the sensory systems that enables the body to assess and process information about the external environment. In the absence of vision, a blind person loses contact with the outside world and develops faulty motor patterns, which results in postural deficiencies. However, literature regarding the development of such deficiencies is limited. The aim of this study was to discuss the effect of absence of vision on posture, the possible biomechanics behind the ...

FM contract relationships: from mobilisation to sustainable partnership

OpenAIRE

Ellison, I.; Owen, S.

2010-01-01

Purpose / theory\\ud Outsourcing is a fundamental business model for the Facilities Management (FM) industry. To enable sustained mutual success the parties involved must seek to understand the unique, socially constructed, and often highly complex situational realities of the organisational ecologies they are engaged in. The FM industry can unlock improved performance and strategic credibility through an appreciation of the need for different conversations.\\ud Design / methodology / approach\\...

Sitting Posture Monitoring System Based on a Low-Cost Load Cell Using Machine Learning

Directory of Open Access Journals (Sweden)

Jongryun Roh

2018-01-01

Full Text Available Sitting posture monitoring systems (SPMSs help assess the posture of a seated person in real-time and improve sitting posture. To date, SPMS studies reported have required many sensors mounted on the backrest plate and seat plate of a chair. The present study, therefore, developed a system that measures a total of six sitting postures including the posture that applied a load to the backrest plate, with four load cells mounted only on the seat plate. Various machine learning algorithms were applied to the body weight ratio measured by the developed SPMS to identify the method that most accurately classified the actual sitting posture of the seated person. After classifying the sitting postures using several classifiers, average and maximum classification rates of 97.20% and 97.94%, respectively, were obtained from nine subjects with a support vector machine using the radial basis function kernel; the results obtained by this classifier showed a statistically significant difference from the results of multiple classifications using other classifiers. The proposed SPMS was able to classify six sitting postures including the posture with loading on the backrest and showed the possibility of classifying the sitting posture even though the number of sensors is reduced.

Postural control in women with breast hypertrophy

Directory of Open Access Journals (Sweden)

Alessandra Ferreira Barbosa

2012-07-01

Full Text Available OBJECTIVES: The consequences of breast hypertrophy have been described based on the alteration of body mass distribution, leading to an impact on psychological and physical aspects. The principles of motor control suggest that breast hypertrophy can lead to sensorimotor alterations and the impairment of body balance due to postural misalignment. The aim of this study is to evaluate the postural control of women with breast hypertrophy under different sensory information conditions. METHOD: This cross-sectional study included 14 women with breast hypertrophy and 14 without breast hypertrophy, and the mean ages of the groups were 39 ±15 years and 39±16 years, respectively. A force platform was used to assess the sensory systems that contribute to postural control: somatosensory, visual and vestibular. Four postural conditions were sequentially tested: eyes open and fixed platform, eyes closed and fixed platform, eyes open and mobile platform, and eyes closed and mobile platform. The data were processed, and variables related to the center of pressure were analyzed for each condition. The Kruskal-Wallis test was used to compare the conditions between the groups for the area of center of pressure displacement and the velocity of center of pressure displacement in the anterior-posterior and medial-lateral directions. The alpha level error was set at 0.05. RESULTS: Women with breast hypertrophy presented an area that was significantly higher for three out of four conditions and a higher velocity of center of pressure displacement in the anterior-posterior direction under two conditions: eyes open and mobile platform and eyes closed and mobile platform. CONCLUSIONS: Women with breast hypertrophy have altered postural control, which was demonstrated by the higher area and velocity of center of pressure displacement.

Influence of Functional Head Postures on the Dynamic Functional ...

African Journals Online (AJOL)

Background: The dentist utilizes supine position during therapeutic procedures, while the patients assumes extended head posture during mastication. It is critical for the restorative dentist to evaluate and understand the possible effect of change in head posture on occlusal contacts. An understanding of the possible effect ...

Standing working posture compared in pregnant and non-pregnant conditions.

Science.gov (United States)

Paul, J A; Frings-Dresen, M H

1994-09-01

During pregnancy, an increase in body weight occurs together with changes in body weight distribution and in fit between body dimensions and workplace layout. These changes may cause alterations in working posture which may, in turn, have adverse consequences for the biomechanical load on the musculoskeletal system and so increase the risk of musculoskeletal disorders. Using photographic posture registration, the standing working posture was studied in 27 women during the last stage of pregnancy and after delivery (the experimental group). The women performed an assembly task while standing at various workplace layouts. The postural differences between the pregnant condition and the non-pregnant condition were studied and the effect of the various workplace layouts assessed. Ten non-pregnant controls were also studied twice to establish the effect of the time interval between the measuring occasions. We found that the women of the experimental group stood further from the work surface in the pregnant condition compared to the non-pregnant condition, the hips were positioned more backwards, and, in order to reach the tesk, they increased the flexion of the trunk, increased the anteflexion of the upper arms, and extended the arms more. At the workplace layout in which the work surface height was self-selected, the postural differences due to pregnancy were smallest or even absent, compared to the postural differences in the other workplace layouts studied. Ergonomists and workers in occupational health services should be alert to the consequences for the biomechanical load on the musculoskeletal system and the risk of development of health complaints caused by postural changes due to pregnancy. An adjustable workplace layout may prevent some problems.

Age-related effects on postural control under multi-task conditions.

Science.gov (United States)

Granacher, Urs; Bridenbaugh, Stephanie A; Muehlbauer, Thomas; Wehrle, Anja; Kressig, Reto W

2011-01-01

Changes in postural sway and gait patterns due to simultaneously performed cognitive (CI) and/or motor interference (MI) tasks have previously been reported and are associated with an increased risk of falling in older adults. The objectives of this study were to investigate the effects of a CI and/or MI task on static and dynamic postural control in young and elderly subjects, and to find out whether there is an association between measures of static and dynamic postural control while concurrently performing the CI and/or MI task. A total of 36 healthy young (n = 18; age: 22.3 ± 3.0 years; BMI: 21.0 ± 1.6 kg/m(2)) and elderly adults (n = 18; age: 73.5 ± 5.5 years; BMI: 24.2 ± 2.9 kg/m(2)) participated in this study. Static postural control was measured during bipedal stance, and dynamic postural control was obtained while walking on an instrumented walkway. Irrespective of the task condition, i.e. single-task or multiple tasks, elderly participants showed larger center-of-pressure displacements and greater stride-to-stride variability than younger participants. Associations between measures of static and dynamic postural control were found only under the single-task condition in the elderly. Age-related deficits in the postural control system seem to be primarily responsible for the observed results. The weak correlations detected between static and dynamic measures could indicate that fall-risk assessment should incorporate dynamic measures under multi-task conditions, and that skills like erect standing and walking are independent of each other and may have to be trained complementarily. Copyright © 2010 S. Karger AG, Basel.

The effect of sustained low-intensity contractions on supraspinal fatigue in human elbow flexor muscles

DEFF Research Database (Denmark)

Søgaard, Karen; Gandevia, Simon C; Todd, Gabrielle

2006-01-01

Subjects quickly fatigue when they perform maximal voluntary contractions (MVCs). Much of the loss of force is from processes within muscle (peripheral fatigue) but some occurs because voluntary activation of the muscle declines (central fatigue). The role of central fatigue during submaximal...... contractions is not clear. This study investigated whether central fatigue developed during prolonged low-force voluntary contractions. Subjects (n=9) held isometric elbow flexions of 15% MVC for 43 min. Voluntary activation was measured during brief MVCs every 3 min. During each MVC, transcranial magnetic...... several minutes while MVC torque only returned to approximately 85% baseline. The resting twitch showed no recovery. Thus, as well as fatigue in the muscle, the prolonged low-force contraction produced progressive central fatigue, and some of this impairment of the subjects' ability to drive the muscle...

Do posture correction exercises have to be boring? Using unstable surfaces to prevent poor posture in children

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Agnieszka Jankowicz-Szymanska

2016-07-01

Full Text Available Introduction: Poor posture in children is a common problem. It appears most often in early school-age children and, if not corrected, progresses quickly as they mature. Aim of the research: To find a method that can prevent poor posture, is effective and attractive for children, and can be used on a wide scale in state schools. Material and methods : Seventy-seven first year pupils were tested at the beginning and at the end of the school year. Nineteen children undertook corrective exercises using unstable surfaces; 41 children sat on sensorimotor pillows during classes; and 17 children were the control group. Body mass and body height were measured. Body mass index was calculated. The symmetry of the position of selected skeletal points was assessed: the acromions, lower angles of the scapulas, apexes of the iliac crests, antero-superior iliac spine, and postero-superior iliac spine using a Duometer electronic device. The differences between the groups and changes between the first and second study for each group were estimated. Results : In the first study there were no significant differences in quality of posture. In the second study a significant improvement was noted in symmetry of the shoulders, scapulas, and pelvis in children who sat on sensorimotor pillows, as well as the position of the iliac crests and iliac spines in children exercising regularly on unstable surfaces. Conclusions: Exercises using unstable surfaces and sitting on sensorimotor pillows during classes might be an effective alternative to traditional posture correction exercises.

Inversion of Side Scan Sonar Motion and Posture in Seabed Geomorphology

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Tao Weiliang

2017-08-01

Full Text Available Side scan sonar measurement platform, affected by underwater environment and its own motion precision, inevitably has posture and motion disturbance, which greatly affects accuracy of geomorphic image formation. It is difficult to sensitively and accurately capture these underwater disturbances by relying on auxiliary navigation devices. In this paper, we propose a method to invert motion and posture information of the measurement platform by using the matching relation between the strip images. The inversion algorithm is the key link in the image mosaic frame of side scan sonar, and the acquired motion posture information can effectively improve seabed topography and plotting accuracy and stability. In this paper, we first analyze influence of platform motion and posture on side scan sonar mapping, and establish the correlation model between motion, posture information and strip image matching information. Then, based on the model, a reverse neural network is established. Based on input, output of neural network, design of and test data set, a motion posture inversion mechanism based on strip image matching information is established. Accuracy and validity of the algorithm are verified by the experimental results.

Development of polygonal surface version of ICRP reference phantoms: Preliminary study for posture change

International Nuclear Information System (INIS)

Nguyen, Tat Thang; Yeom, Yeon Soo; Han, Min Cheol; Kim, Chan Hyeong

2013-01-01

Even though International Commission on Radiological Protection (ICRP) officially adopted a set of adult male and female voxel phantoms as the ICRP reference phantoms, there are several critical limitations due to the nature of voxel geometry and their low voxel resolutions. In order to overcome these limitations of the ICRP phantoms, we are currently developing polygonal surface version of ICRP reference phantoms by directly converting the ICRP voxel phantoms to polygonal surface geometries. Among the many advantages of the ICRP polygonal surface phantom, especially, it is flexible and deformable. In principle, it is, therefore, possible to make the posture-changed ICRP phantoms which can provide more accurate dose values for exposure situations strongly relevant to worker's postures. As a preliminary study for developing the posture-changed ICRP phantoms, in this work we changed the posture of the preliminary version of ICRP male polygon-surface phantom constructed in the previous study. Organ doses were then compared between original and posture-changed phantoms. In the present study, we successfully changed a posture of the preliminary version of ICRP male polygon-surface phantom to the walking posture. From this results, it was explicitly shown that the polygon-surface version of the ICRP phantoms can be sufficiently modified to be various postures with the posture-changing method used in this study. In addition, it was demonstrated that phantom's posture must be considered in certain exposure situations, which can differ dose values from the conventional standing-posture phantom

Postural adaptations to repeated optic flow stimulation in older adults

OpenAIRE

O’Connor, Kathryn W.; Loughlin, Patrick J.; Redfern, Mark S.; Sparto, Patrick J.

2008-01-01

The purpose of this study is to understand the processes of adaptation (changes in within-trial postural responses) and habituation (reductions in between-trial postural responses) to visual cues in older and young adults. Of particular interest were responses to sudden increases in optic flow magnitude. The postural sway of 25 healthy young adults and 24 healthy older adults was measured while subjects viewed anterior-posterior 0.4 Hz sinusoidal optic flow for 45 s. Three trials for each of ...

Posture changes and subfoveal choroidal blood flow.

Science.gov (United States)

Longo, Antonio; Geiser, Martial H; Riva, Charles E

2004-02-01

To evaluate the effect of posture change on subfoveal choroidal blood flow (ChBF) in normal volunteers. The pulsatile, nonpulsatile, and mean ChBF were measured with laser Doppler flowmetry in 11 healthy volunteers with a mean age of 32 +/- 13 (SD) years. The posture of the subjects was changed from standing (90 degrees ), to supine (-8 degrees ), and back to standing, with a mechanically driven table. During the whole experimental procedure, ChBF and heart rate (HR) were continuously recorded. After 30 seconds in standing position, the subjects were tilted to supine during approximately 30 seconds. They remained in this position for approximately 2 minutes, after which they were tilted back to the standing position (recovery), where they remained for another approximately 2 minutes. Systemic brachial artery blood pressure (BP) was measured in the baseline, supine, and recovery positions. This procedure was repeated to measure the intraocular pressure (IOP) at the different postures. Mean BP did not change significantly throughout the experimental procedure. As the body was tilted from standing to supine, HR decreased by 16% (P blood velocity. Based on previously reported experimental data that indicate that the ocular perfusion pressure increases less than predicted by purely hydrostatic considerations when the body is tilted from the standing to the supine position, the observed increase in ChBF suggests a passive response of the choroidal circulation to the posture change.

Ergonomic analysis of construction worker's body postures using wearable mobile sensors.

Science.gov (United States)

Nath, Nipun D; Akhavian, Reza; Behzadan, Amir H

2017-07-01

Construction jobs are more labor-intensive compared to other industries. As such, construction workers are often required to exceed their natural physical capability to cope with the increasing complexity and challenges in this industry. Over long periods of time, this sustained physical labor causes bodily injuries to the workers which in turn, conveys huge losses to the industry in terms of money, time, and productivity. Various safety and health organizations have established rules and regulations that limit the amount and intensity of workers' physical movements to mitigate work-related bodily injuries. A precursor to enforcing and implementing such regulations and improving the ergonomics conditions on the jobsite is to identify physical risks associated with a particular task. Manually assessing a field activity to identify the ergonomic risks is not trivial and often requires extra effort which may render it to be challenging if not impossible. In this paper, a low-cost ubiquitous approach is presented and validated which deploys built-in smartphone sensors to unobtrusively monitor workers' bodily postures and autonomously identify potential work-related ergonomic risks. Results indicates that measurements of trunk and shoulder flexions of a worker by smartphone sensory data are very close to corresponding measurements by observation. The proposed method is applicable for workers in various occupations who are exposed to WMSDs due to awkward postures. Examples include, but are not limited to industry laborers, carpenters, welders, farmers, health assistants, teachers, and office workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimating Co-Contraction Activation of Trunk Muscles Using a Novel Musculoskeletal Model for Pregnant Women

Directory of Open Access Journals (Sweden)

Saori Morino

2017-10-01

Full Text Available Weight gain and stretched abdominal muscles from an enlarged gravid uterus are remarkable features during pregnancy. These changes elicit postural instability and place strain on body segments, contributing to lower back pain. In general, the agonist and antagonist muscles act simultaneously to increase joint stabilization; however, this can cause additional muscle stress during movement. Furthermore, this activation can be observed in pregnant women because of their unstable body joints. Hence, physical modalities based on assessments of muscle activation are useful for managing low back pain during pregnancy. Musculoskeletal models are common when investigating muscle load. However, it is difficult to apply such models to pregnant women and estimate the co-contraction of muscles using musculoskeletal models. Therefore, the purpose of this study is to construct a musculoskeletal model for pregnant women that estimates the co-contraction of trunk muscles. First, motion analysis was conducted on a pregnant woman and the muscle activations of the rectus abdominis and erector spinae were measured. Then, the musculoskeletal model was specifically modified for pregnant women. Finally, the co-contraction was estimated from the results of the musculoskeletal model and electromyography data using a genetic algorithm. With the proposed methods, weakened abdominal muscle torque and the co-contraction activation of trunk muscles were estimated successfully.

Orthostatic intolerance and postural tachycardia syndrome as suspected adverse effects of vaccination against human papilloma virus

DEFF Research Database (Denmark)

Brinth, Louise S; Pors, Kirsten; Theibel, Ann C

2015-01-01

of postural orthostatic tachycardia syndrome (POTS) rested on finding a sustained heart rate increment of >30min(-1) (>40min(-1) in adolescents) or to levels >120min(-1) during orthostatic challenge. RESULTS: 35 women aged 23.3±7.1 years participated. Twenty-five had a high level of physical activity before...... vaccination and irregular periods were reported by all patients not on treatment with oral contraception. Serum bilirubin was below the lower detection limit in 17 patients. Twenty-one of the referred patients fulfilled the criteria for a diagnosis of POTS (60%, 95%CI 43-77%). All patients had orthostatic...

Fitness, Balance Efficacy, and Postural Control in Community-Dwelling Older Adults

OpenAIRE

Anna Lee; John R. Biggan; Christopher Ray

2016-01-01

Age-related declines in postural control and physical fitness are strong risk factors for falls in older adults. Balance efficacy has been utilized to identify poor postural control, reduced physical function, and fall risk. However, it is not clear as to whether balance efficacy is truly a better predictor of functional fitness outcomes or postural control. Distinguishing these associations is an important step in the...

Analysis of postural load during tasks related to milking cows-a case study.

Science.gov (United States)

Groborz, Anna; Tokarski, Tomasz; Roman-Liu, Danuta

2011-01-01

The aim of this study was to analyse postural load during tasks related to milking cows of 2 farmers on 2 different farms (one with a manual milk transport system, the other with a fully automated milk transport system) as a case study. The participants were full-time farmers, they were both healthy and experienced in their job. The Ovako Working Posture Analyzing System (OWAS) was used to evaluate postural load and postural risk. Postural load was medium for the farmer on the farm with a manual milk transport system and high for the farmer working on the farm with a fully automated milk transport system. Thus, it can be concluded that a higher level of farm mechanization not always mean that the farmer's postural load is lower, but limitation of OWAS should be considered.

Postural stability and ankle sprain history in athletes compared to uninjured controls.

Science.gov (United States)

Huurnink, Arnold; Fransz, Duncan P; Kingma, Idsart; Verhagen, Evert A L M; van Dieën, Jaap H

2014-02-01

Diminished postural stability is a risk factor for ankle sprain occurrence and ankle sprains result in impaired postural stability. To date, ankle sprain history has not been taken into account as a determinant of postural stability, while it could possibly specify subgroups of interest. Postural stability was compared between 18 field hockey athletes who had recovered from an ankle sprain (mean (SD); 3.6 (1.5) months post-injury), and 16 uninjured controls. Force plate and kinematics parameters were calculated during single-leg standing: mean center of pressure speed, mean absolute horizontal ground reaction force, mean absolute ankle angular velocity, and mean absolute hip angular velocity. Additionally, cluster analysis was applied to the 'injured' participants, and the cluster with diminished postural stability was compared to the other participants with respect to ankle sprain history. MANCOVA showed no significant difference between groups in postural stability (P = 0.68). A self-reported history of an (partial) ankle ligament rupture was typically present in the cluster with diminished postural stability. Subsequently, a 'preceding rupture' was added as a factor in the MANCOVA, which showed a significant association between diminished postural stability and a 'preceding rupture' (P = 0.01), for all four individual parameters (P: 0.001-0.029; Cohen's d: 0.96-2.23). Diminished postural stability is not apparent in all previously injured athletes. However, our analysis suggests that an (mild) ankle sprain with a preceding severe ankle sprain is associated with impaired balance ability. Therefore, sensorimotor training may be emphasized in this particular group and caution is warranted in return to play decisions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Posture estimation system for underground mine vehicles

CSIR Research Space (South Africa)

Hlophe, K

2010-09-01

Full Text Available Page 1 of 8 25th International Conference of CAD/CAM, Robotics & Factories of the Future Conference, 13-16 July 2010, Pretoria, South Africa A POSTURE ESTIMATION SYSTEM FOR UNDERGROUND MINE VEHICLES Khonzumusa Hlophe1, Gideon Ferreira2... and the transmitter. The main difference between the three systems is their implementation. This paper describes an implementation of a posture estimation system for underground mine vehicles. The paper is organized as follows. In the next section, a brief...

Reflex control of the spine and posture: a review of the literature from a chiropractic perspective

Directory of Open Access Journals (Sweden)

Schlappi Mark

2005-08-01

Full Text Available Abstract Objective This review details the anatomy and interactions of the postural and somatosensory reflexes. We attempt to identify the important role the nervous system plays in maintaining reflex control of the spine and posture. We also review, illustrate, and discuss how the human vertebral column develops, functions, and adapts to Earth's gravity in an upright position. We identify functional characteristics of the postural reflexes by reporting previous observations of subjects during periods of microgravity or weightlessness. Background Historically, chiropractic has centered around the concept that the nervous system controls and regulates all other bodily systems; and that disruption to normal nervous system function can contribute to a wide variety of common ailments. Surprisingly, the chiropractic literature has paid relatively little attention to the importance of neurological regulation of static upright human posture. With so much information available on how posture may affect health and function, we felt it important to review the neuroanatomical structures and pathways responsible for maintaining the spine and posture. Maintenance of static upright posture is regulated by the nervous system through the various postural reflexes. Hence, from a chiropractic standpoint, it is clinically beneficial to understand how the individual postural reflexes work, as it may explain some of the clinical presentations seen in chiropractic practice. Method We performed a manual search for available relevant textbooks, and a computer search of the MEDLINE, MANTIS, and Index to Chiropractic Literature databases from 1970 to present, using the following key words and phrases: "posture," "ocular," "vestibular," "cervical facet joint," "afferent," "vestibulocollic," "cervicocollic," "postural reflexes," "spaceflight," "microgravity," "weightlessness," "gravity," "posture," and "postural." Studies were selected if they specifically tested any or

The Improvement of Dental Posture Using Personalized Biofeedback.

Science.gov (United States)

Thanathornwong, Bhornsawan; Suebnukarn, Siriwan

2015-01-01

Dentists are subject to staying in static or awkward postures for long periods due to their highly concentrated work. This study describes a real-time personalized biofeedback system developed for dental posture training with the use of vibrotactile biofeedback. The real-time personalized biofeedback system was an integrated solution that comprised of two components: 1) a wearable device that contained an accelerometer sensor for measuring the tilt angle of the body (input) and provided real-time vibrotactile biofeedback (output); and 2) software for data capturing, processing, and personalized biofeedback generation. The implementation of real-time personalized vibrotactile feedback was computed using Hidden Markov Models (HMMs). For the test case, we calculated the probability and log-likelihood of the test movements under the Work related Musculoskeletal Disorders (WMSD) and non-WMSD HMMs. The vibrotactile biofeedback was provided to the user via a wearable device for a WMSD-predicted case. In the system evaluation, a randomized crossover trial was conducted to compare dental posture measure using tilt angles of the upper back and muscle activities of those dental students that received vibrotactile biofeedback from the system with the control group against the dental students who received no feedback. The participants who received feedback from the system had a lower tilt angle at 10th, 50th, and 90th percentiles of Backx and Backy, as well as muscular load, which were statistically different (pbiofeedback system for posture training in dental students is feasible and associated with quantitative improvements of the dental posture.

Contract theory and EU Contract Law

OpenAIRE

Hesselink, M.W.; Twigg-Flesner, C.

2016-01-01

This paper explores the relationship between contract theory and European contract law. In particular, it confronts the leading contract law theories with the main characteristics of EU contract law. The conclusion is that the two do not match well. In particular, monist normative contract theories are largely irreconcilable with the contract law of the EU. The paper further addresses the main implications of this mismatch, both for contract theory and for EU contract law. It suggests that in...

The Effect of Body Posture on Brain Glymphatic Transport.

Science.gov (United States)

Lee, Hedok; Xie, Lulu; Yu, Mei; Kang, Hongyi; Feng, Tian; Deane, Rashid; Logan, Jean; Nedergaard, Maiken; Benveniste, Helene

2015-08-05

The glymphatic pathway expedites clearance of waste, including soluble amyloid β (Aβ) from the brain. Transport through this pathway is controlled by the brain's arousal level because, during sleep or anesthesia, the brain's interstitial space volume expands (compared with wakefulness), resulting in faster waste removal. Humans, as well as animals, exhibit different body postures during sleep, which may also affect waste removal. Therefore, not only the level of consciousness, but also body posture, might affect CSF-interstitial fluid (ISF) exchange efficiency. We used dynamic-contrast-enhanced MRI and kinetic modeling to quantify CSF-ISF exchange rates in anesthetized rodents' brains in supine, prone, or lateral positions. To validate the MRI data and to assess specifically the influence of body posture on clearance of Aβ, we used fluorescence microscopy and radioactive tracers, respectively. The analysis showed that glymphatic transport was most efficient in the lateral position compared with the supine or prone positions. In the prone position, in which the rat's head was in the most upright position (mimicking posture during the awake state), transport was characterized by "retention" of the tracer, slower clearance, and more CSF efflux along larger caliber cervical vessels. The optical imaging and radiotracer studies confirmed that glymphatic transport and Aβ clearance were superior in the lateral and supine positions. We propose that the most popular sleep posture (lateral) has evolved to optimize waste removal during sleep and that posture must be considered in diagnostic imaging procedures developed in the future to assess CSF-ISF transport in humans. The rodent brain removes waste better during sleep or anesthesia compared with the awake state. Animals exhibit different body posture during the awake and sleep states, which might affect the brain's waste removal efficiency. We investigated the influence of body posture on brainwide transport of inert

Evaluation of body posture in individuals with internal temporomandibular joint derangement.

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Munhoz, Wagner Cesar; Marques, Amélia Pasqual; de Siqueira, José Tadeu Tesseroli

2005-10-01

Temporomandibular dysfunctions (TMD) comprise a great number of disruptions that may affect the temporomandibular joint (TMJ), the masticatory muscles, or both. TMJ internal derangement is a specific type of TMD, of which the etiology and physiopathology are broadly unknown, but have been suggested to be linked to head, neck, and body posture factors. This study aimed at verifying possible relationships between body posture and TMJ internal derangements (TMJ-id), by comparing 30 subjects presenting typical TMJ-id signs to 20 healthy subjects. Subjects' clinical evaluations included anamnesis, stomatognatic system evaluation, and plotting analysis on body posture photographs. No statistically significant differences were found between the groups. Results do not support the assertion that body posture plays a role in causing or enhancing TMD; however, these results should be cautiously considered because of the small number of subjects evaluated and the many posture variables submitted to statistical procedures that lead to high standard deviations.

The effects of foot morphology and anthropometry on unipodal postural control

Directory of Open Access Journals (Sweden)

Angelica C. Alonso

2016-03-01

Full Text Available Abstract The maintenance of posture is a constant challenge for the body, as it requires rapid and accurate responses to unforeseen disturbances, which are needed to prevent falls and maintain balance. The purpose of the present study was to compare different types of plantar arch in relation to postural balance, and analyze the relationships between variations the plantar arch and anthropometric characteristics of the feet with unipedal static balance. We evaluated 100 men and women between the ages of 20 and 40 years old, to determine anthropometry and posturography with a force platform. There was a weak correlation between plantar arches and anthropometric measurements and postural balance, except for the length of the male foot, which showed a correlation between increased size and poorer static balance. We conclude that the type of plantar arch does not influence postural balance, and of the anthropometric factors, only foot length was related to postural balance.

Rater reliability and construct validity of a mobile application for posture analysis.

Science.gov (United States)

Szucs, Kimberly A; Brown, Elena V Donoso

2018-01-01

[Purpose] Measurement of posture is important for those with a clinical diagnosis as well as researchers aiming to understand the impact of faulty postures on the development of musculoskeletal disorders. A reliable, cost-effective and low tech posture measure may be beneficial for research and clinical applications. The purpose of this study was to determine rater reliability and construct validity of a posture screening mobile application in healthy young adults. [Subjects and Methods] Pictures of subjects were taken in three standing positions. Two raters independently digitized the static standing posture image twice. The app calculated posture variables, including sagittal and coronal plane translations and angulations. Intra- and inter-rater reliability were calculated using the appropriate ICC models for complete agreement. Construct validity was determined through comparison of known groups using repeated measures ANOVA. [Results] Intra-rater reliability ranged from 0.71 to 0.99. Inter-rater reliability was good to excellent for all translations. ICCs were stronger for translations versus angulations. The construct validity analysis found that the app was able to detect the change in the four variables selected. [Conclusion] The posture mobile application has demonstrated strong rater reliability and preliminary evidence of construct validity. This application may have utility in clinical and research settings.

A new approach for assessing sleep duration and postures from ambulatory accelerometry.

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Cornelia Wrzus

Full Text Available Interest in the effects of sleeping behavior on health and performance is continuously increasing-both in research and with the general public. Ecologically valid investigations of this research topic necessitate the measurement of sleep within people's natural living contexts. We present evidence that a new approach for ambulatory accelerometry data offers a convenient, reliable, and valid measurement of both people's sleeping duration and quality in their natural environment. Ninety-two participants (14-83 years wore acceleration sensors on the sternum and right thigh while spending the night in their natural environment and following their normal routine. Physical activity, body posture, and change in body posture during the night were classified using a newly developed classification algorithm based on angular changes of body axes. The duration of supine posture and objective indicators of sleep quality showed convergent validity with self-reports of sleep duration and quality as well as external validity regarding expected age differences. The algorithms for classifying sleep postures and posture changes very reliably distinguished postures with 99.7% accuracy. We conclude that the new algorithm based on body posture classification using ambulatory accelerometry data offers a feasible and ecologically valid approach to monitor sleeping behavior in sizable and heterogeneous samples at home.

Investigation of postural edema in the lower extremities of traffic control workers

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Ana Paula Nunes Pereira Brito

2013-12-01

Full Text Available OBJECTIVE: Determine the prevalence of postural edema and investigate whether working posture - sitting down or standing up - affect its frequency. METHODS: Sixteen traffic control agents were assessed by water displacement volumetry and the results were analyzed in two groups, depending on working posture. Those who worked standing up for more than 4 hours were allocated to the SU group and those who worked sitting down for more than 4 hours were allocated to the SD group. Each worker was assessed before and after their working shift for three consecutive days. Data were analyzed using ANOVA and the test of equality of two proportions. The significance level was set at p ≤ 0.05. The assessment showed that members of both groups had postural edema of the lower extremities (p ≤ 0.001. RESULTS: When the frequency of postural edema was compared across groups, a trend was observed for greater edema formation in the SU group than in the SD group, although without statistically significant difference. CONCLUSION: It was concluded that traffic control agents suffer postural edema after 4 hours working in either of the postures investigated although with a predominance of edema formation among those who work standing up.

Evaluation of Neutral Body Posture on Shuttle Mission STS-57 (SPACEHAB-1). Revision

Science.gov (United States)

Mount, Frances E.; Whitmore, Mihriban; Stealey, Sheryl L.

2003-01-01

Research has shown that the space environment induces physiological changes in the human body, such as fluid shifts in the upper body and chest cavity, spinal lengthening, muscular atrophy, space motion sickness, cardiopulmonary deconditioning, and bone mass loss, as well as some changes in visual perception. These require a period of adaptation and can substantially affect both crew member performance and posture. These physiological effects, when work activities are conducted, have been known to impact the body's center of gravity, reach, flexibility, and dexterity. All these aspects of posture must be considered to safely and efficiently design space systems and hardware. NASA has documented its microgravity body posture in the Man-Systems Integration Standards (MSIS); the space community uses the MSIS posture to design workstations and tools for space application. However, the microgravity body posture should be further investigated for several reasons, including small sample size in previous studies, possible imprecision, and lack of detail. JSC undertook this study to investigate human body posture exhibited under microgravity conditions. STS-57 crew members were instructed to assume a relaxed posture that was not oriented to any work area or task. Crew members were asked to don shorts and tank tops and to be blindfolded while data were recorded. Video data were acquired once during the mission from each of the six crew members. No one crew member exhibited the typical NBP called out in the MSIS; one composite posture is not adequate. A range of postures may be more constructive for design purposes. Future evaluations should define precise posture requirements for workstation, glove box, maintenance, foot-restraint, and handhold activities.

Difference in postural control between patients with functional and mechanical ankle instability.

Science.gov (United States)

Chen, Henry; Li, Hong-Yun; Zhang, Jian; Hua, Ying-Hui; Chen, Shi-Yi

2014-10-01

Lateral ankle sprain is one of the most common injuries. Since the structural and pathological differences in mechanical ankle instability (MAI) and functional ankle instability (FAI) may not be the same, it may be better to treat these as separate groups. The purpose of this study was to compare the difference in postural sway between MAI and FAI in patients with chronic ankle instability (CAI). Twenty-six patients with CAI and 14 healthy control participants were included in the study. The CAI patients were subdivided into MAI (15 patients) and FAI (11 patients) groups. Patients who were diagnosed with lateral ankle ligaments rupture by magnetic resonance imaging and ultrasonography were assigned to the MAI group. All participants performed single-limb postural sway tests 3 times on each leg with eyes closed and open. The average distances from the mean center of pressure position in the mediolateral and anteroposterior directions were recorded and compared among the 3 groups. The unstable ankles in the MAI group showed significantly greater postural sway in the anterior, posterior, and medial directions compared with those in the control group with eyes closed. With eyes open, significantly greater postural sway was found in the anterior direction. In the FAI group, no difference was found in postural sway compared with those in the control group. The MAI group showed significantly greater postural sway in the anterior direction compared with the FAI group with eyes closed and open. No significant difference in postural sway was found between the unstable and stable ankles in the MAI or FAI groups, with or without vision. Patients with MAI have deficits in postural control, especially in anterior-posterior directions. However, no difference was found in postural sway in patients with FAI compared with healthy people. As MAI patients suffer from deficits in postural control, balance training should be applied in those patients. In addition, special training

Adolescent standing postural response to backpack loads: a randomised controlled experimental study

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Pirunsan Ubon

2002-04-01

Full Text Available Abstract Background Backpack loads produce changes in standing posture when compared with unloaded posture. Although 'poor' unloaded standing posture has been related to spinal pain, there is little evidence of whether, and how much, exposure to posterior load produces injurious effects on spinal tissue. The objective of this study was to describe the effect on adolescent sagittal plane standing posture of different loads and positions of a common design of school backpack. The underlying study aim was to test the appropriateness of two adult 'rules-of-thumb'-that for postural efficiency, backpacks should be worn high on the spine, and loads should be limited to 10% of body weight. Method A randomised controlled experimental study was conducted on 250 adolescents (12–18 years, randomly selected from five South Australian metropolitan high schools. Sagittal view anatomical points were marked on head, neck, shoulder, hip, thigh, knee and ankle. There were nine experimental conditions: combinations of backpack loads (3, 5 or 10% of body weight and positions (backpack centred at T7, T12 or L3. Sagittal plane photographs were taken of unloaded standing posture (baseline, and standing posture under the experimental conditions. Posture was quantified from the x (horizontal coordinate of each anatomical point under each experimental condition. Differences in postural response were described, and differences between conditions were determined using Analysis of Variance models. Results Neither age nor gender was a significant factor when comparing postural response to backpack loads or conditions. Backpacks positioned at T7 produced the largest forward (horizontal displacement at all the anatomical points. The horizontal position of all anatomical points increased linearly with load. Conclusion There is evidence refuting the 'rule-of-thumb' to carry the backpack high on the back. Typical school backpacks should be positioned with the centre at waist or

Influence of dental occlusion on postural control and plantar pressure distribution.

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Scharnweber, Benjamin; Adjami, Frederic; Schuster, Gabriele; Kopp, Stefan; Natrup, Jörg; Erbe, Christina; Ohlendorf, Daniela

2017-11-01

The number of studies investigating correlations between the temporomandibular system and body posture, postural control or plantar pressure distribution is continuously increasing. If a connection can be found, it is often of minor influence or for only a single parameter. However, small subject groups are critical. This study was conducted to define correlations between dental parameters, postural control and plantar pressure distribution in healthy males. In this study, 87 male subjects with an average age of 25.23 ± 3.5 years (ranging from 18 to 35 years) were examined. Dental casts of the subjects were analyzed. Postural control and plantar pressure distribution were recorded by a force platform. Possible orthodontic and orthopedic factors of influence were determined by either an anamnesis or a questionnaire. All tests performed were randomized and repeated three times each for intercuspal position (ICP) and blocked occlusion (BO). For a statistical analysis of the results, non-parametric tests (Wilcoxon-Matched-Pairs-Test, Kruskall-Wallis-Test) were used. A revision of the results via Bonferroni-Holm correction was considered. ICP increases body sway in the frontal (p ≤ 0.01) and sagittal planes (p ≤ 0.03) compared to BO, whereas all other 29 correlations were independent of the occlusion position. For both of the ICP or BO cases, Angle-class, midline-displacement, crossbite, or orthodontic therapy were found to have no influence on postural control or plantar pressure distribution (p > 0.05). However, the contact time of the left foot decreased (p ≤ 0.001) while detecting the plantar pressure distribution in each position. Persistent dental parameters have no effect on postural sway. In addition, postural control and plantar pressure distribution have been found to be independent postural criteria.

An investigation of rugby scrimmaging posture and individual maximum pushing force.

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Wu, Wen-Lan; Chang, Jyh-Jong; Wu, Jia-Hroung; Guo, Lan-Yuen

2007-02-01

Although rugby is a popular contact sport and the isokinetic muscle torque assessment has recently found widespread application in the field of sports medicine, little research has examined the factors associated with the performance of game-specific skills directly by using the isokinetic-type rugby scrimmaging machine. This study is designed to (a) measure and observe the differences in the maximum individual pushing forward force produced by scrimmaging in different body postures (3 body heights x 2 foot positions) with a self-developed rugby scrimmaging machine and (b) observe the variations in hip, knee, and ankle angles at different body postures and explore the relationship between these angle values and the individual maximum pushing force. Ten national rugby players were invited to participate in the examination. The experimental equipment included a self-developed rugby scrimmaging machine and a 3-dimensional motion analysis system. Our results showed that the foot positions (parallel and nonparallel foot positions) do not affect the maximum pushing force; however, the maximum pushing force was significantly lower in posture I (36% body height) than in posture II (38%) and posture III (40%). The maximum forward force in posture III (40% body height) was also slightly greater than for the scrum in posture II (38% body height). In addition, it was determined that hip, knee, and ankle angles under parallel feet positioning are factors that are closely negatively related in terms of affecting maximum pushing force in scrimmaging. In cross-feet postures, there was a positive correlation between individual forward force and hip angle of the rear leg. From our results, we can conclude that if the player stands in an appropriate starting position at the early stage of scrimmaging, it will benefit the forward force production.

Contributions of foot muscles and plantar fascia morphology to foot posture.

Science.gov (United States)

Angin, Salih; Mickle, Karen J; Nester, Christopher J

2018-03-01

The plantar foot muscles and plantar fascia differ between different foot postures. However, how each individual plantar structure contribute to foot posture has not been explored. The purpose of this study was to investigate the associations between static foot posture and morphology of plantar foot muscles and plantar fascia and thus the contributions of these structures to static foot posture. A total of 111 participants were recruited, 43 were classified as having pes planus and 68 as having normal foot posture using Foot Posture Index assessment tool. Images from the flexor digitorum longus (FDL), flexor hallucis longus (FHL), peroneus longus and brevis (PER), flexor hallucis brevis (FHB), flexor digitorum brevis (FDB) and abductor hallucis (AbH) muscles, and the calcaneal (PF1), middle (PF2) and metatarsal (PF3) regions of the plantar fascia were obtained using a Venue 40 ultrasound system with a 5-13 MHz transducer. In order of decreasing contribution, PF3 > FHB > FHL > PER > FDB were all associated with FPI and able to explain 69% of the change in FPI scores. PF3 was the highest contributor explaining 52% of increases in FPI score. Decreased thickness was associated with increased FPI score. Smaller cross sectional area (CSA) in FHB and PER muscles explained 20% and 8% of increase in FPI score. Larger CSA of FDB and FHL muscles explained 4% and 14% increase in FPI score respectively. The medial plantar structures and the plantar fascia appear to be the major contributors to static foot posture. Elucidating the individual contribution of multiple muscles of the foot could provide insight about their role in the foot posture. Copyright © 2018. Published by Elsevier B.V.

POSTUR KERJA DAN RISIKO LOW BACK PAIN PADA PEKERJA PASIRAN

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Denny Nurkertamanda

2017-10-01

Full Text Available Salah satu pekerjaan angkat angkut adalah pekerjaan menurunkan pasir dari atas truk. Dalam bekerja, pekerja menggunakan alat bantu berupa enggrong yang merupakan sekop dengan gagang pendek. Akibat penggunaan enggrong, pekerja bekerja dengan postur tubuh membungkuk. Postur kerja ini menimbulkan potensi low back pain pada pekerja. Penelitian ini merupakan penelitian cross sectional dengan jumlah sampel 9 partisipan. Tujuan dari penelitian adalah untuk mengetahui potensi risiko low back pain berdasarkan sudut kemiringan trunk ketika pekerja bekerja menurunkan pasir dengan enggrong. Sudut kemiringan trunk yang diprediksi meliputi: 1 sudut kemiringan trunk flexion, 2 sudut kemiringan trunk bending, dan 3 sudut kemiringan trunk twisting. Data postur kerja diambil dengan menggunakan kamera 3D Microsoft KinectTM dan dianalisis dengan menggunakan software Siemen Jack metode 3D Static Strength Prediction Program (3DSSPP untuk memprediksi sudut kemiringan trunk. Hasil analisis dari ke-6 postur kerja menunjukkan postur-postur kerja yang sering dilakukan pekerja mempunyai rerata sudut kemiringan trunk flexion sebesar 61,10 ± 10,090, sudut kemiringan trunk bending sebesar 19,80 ± 6,740 dan sudut kemiringan trunk twisting sebesar 20,00 ± 9,030. Rerata sudut kemiringan trunk flexion yang mencapai 87,28 %  dari sudut kemiringan maksimal merupakan penyebab utama risiko low back pain. Sehingga dapat disimpulkan potensi terjadinya low back pain pada pekerja pasiran dapat terjadi. Perlu intervensi ergonomi untuk mencegah dan mengurangi potensi risiko terjadi low back pain pada pekerja pasiran.   Abstract One of the manual matrial handling jobs is the derivative work from the top of the truck. In working the workers use a tool that enggrong which is a short-handed shovel. Due to the use of employee enggrong work with stooped posture. This work posture raises the potential for low back pain in workers. This study is a cross sectional study with a sample of 9

Cortical involvement in anticipatory postural reactions in man

DEFF Research Database (Denmark)

Petersen, Tue Hvass; Rosenberg, Kasper; Petersen, Nicolas Caesar

2009-01-01

All movements are accompanied by postural reactions which ensure that the balance of the body is maintained. It has not been resolved that to what extent the primary motor cortex and corticospinal tract are involved in the control of these reactions. Here, we investigated the contribution...... of the corticospinal tract to the activation of the soleus (SOL) muscle in standing human subjects (n = 10) in relation to voluntary heel raise, anticipatory postural activation of the soleus muscle when the subject pulled a handle and to reflex activation of the soleus muscle when the subject was suddenly pulled...... was observed prior to EMG onset for the external perturbation. These data suggest that the primary motor cortex is involved in activating the SOL muscle as part of an anticipatory postural reaction....

36 CFR 223.111 - Administration of contracts in designated disaster areas.

Science.gov (United States)

2010-07-01

...-sharing arrangement in paragraph (a) of this section, he may allow cancellation of the contract... disaster, (2) The sale of such timber will assist in sustaining the economy of such area, or (3) The sale...

Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size.

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Tai Kubo

Full Text Available Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade, yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. According to a large dataset presented in this study, the body sizes of all nonplantigrades (including nonvolant dinosaurs, nonvolant terrestrial birds, extant mammals, and extinct Nearctic mammals are above 500 g, except for macroscelid mammals (i.e., elephant shrew, a few alvarezsauroid dinosaurs, and nondinosaur ornithodirans (i.e., the immediate ancestors of dinosaurs. When nonplantigrade tetrapods evolved from plantigrade ancestors, lineages with nonplantigrade foot posture exhibited a steady increase in body size following Cope's rule. In contrast, contemporaneous plantigrade lineages exhibited no trend in body size evolution and were largely constrained to small body sizes. This evolutionary pattern of body size specific to foot posture occurred repeatedly during both the Mesozoic and the Cenozoic eras. Although disturbed by the end-Cretaceous extinction, species of mid to large body size have predominantly been nonplantigrade animals from the Jurassic until the present; conversely, species with small body size have been exclusively composed of plantigrades in the nonvolant terrestrial tetrapod fauna.

Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size.

Science.gov (United States)

Kubo, Tai; Kubo, Mugino O

2016-01-01

Dinosaurs had functionally digitigrade or sub-unguligrade foot postures. With their immediate ancestors, dinosaurs were the only terrestrial nonplantigrades during the Mesozoic. Extant terrestrial mammals have different optimal body sizes according to their foot posture (plantigrade, digitigrade, and unguligrade), yet the relationship of nonplantigrade foot posture with dinosaur body size has never been investigated, even though the body size of dinosaurs has been studied intensively. According to a large dataset presented in this study, the body sizes of all nonplantigrades (including nonvolant dinosaurs, nonvolant terrestrial birds, extant mammals, and extinct Nearctic mammals) are above 500 g, except for macroscelid mammals (i.e., elephant shrew), a few alvarezsauroid dinosaurs, and nondinosaur ornithodirans (i.e., the immediate ancestors of dinosaurs). When nonplantigrade tetrapods evolved from plantigrade ancestors, lineages with nonplantigrade foot posture exhibited a steady increase in body size following Cope's rule. In contrast, contemporaneous plantigrade lineages exhibited no trend in body size evolution and were largely constrained to small body sizes. This evolutionary pattern of body size specific to foot posture occurred repeatedly during both the Mesozoic and the Cenozoic eras. Although disturbed by the end-Cretaceous extinction, species of mid to large body size have predominantly been nonplantigrade animals from the Jurassic until the present; conversely, species with small body size have been exclusively composed of plantigrades in the nonvolant terrestrial tetrapod fauna.

Tai Chi training reduced coupling between respiration and postural control.

Science.gov (United States)

Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

2016-01-01

In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body's center-of-mass including those caused by spontaneous respiration. Both aging and disease increase "posturo-respiratory synchronization;" which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86 ± 5 yrs) or educational-control program (n=34, 85 ± 6 yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (ppostural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part from optimization of this multi-system interaction. Copyright © 2015

Does a crouched leg posture enhance running stability and robustness?

Science.gov (United States)

Blum, Yvonne; Birn-Jeffery, Aleksandra; Daley, Monica A; Seyfarth, Andre

2011-07-21

Humans and birds both walk and run bipedally on compliant legs. However, differences in leg architecture may result in species-specific leg control strategies as indicated by the observed gait patterns. In this work, control strategies for stable running are derived based on a conceptual model and compared with experimental data on running humans and pheasants (Phasianus colchicus). From a model perspective, running with compliant legs can be represented by the planar spring mass model and stabilized by applying swing leg control. Here, linear adaptations of the three leg parameters, leg angle, leg length and leg stiffness during late swing phase are assumed. Experimentally observed kinematic control parameters (leg rotation and leg length change) of human and avian running are compared, and interpreted within the context of this model, with specific focus on stability and robustness characteristics. The results suggest differences in stability characteristics and applied control strategies of human and avian running, which may relate to differences in leg posture (straight leg posture in humans, and crouched leg posture in birds). It has been suggested that crouched leg postures may improve stability. However, as the system of control strategies is overdetermined, our model findings suggest that a crouched leg posture does not necessarily enhance running stability. The model also predicts different leg stiffness adaptation rates for human and avian running, and suggests that a crouched avian leg posture, which is capable of both leg shortening and lengthening, allows for stable running without adjusting leg stiffness. In contrast, in straight-legged human running, the preparation of the ground contact seems to be more critical, requiring leg stiffness adjustment to remain stable. Finally, analysis of a simple robustness measure, the normalized maximum drop, suggests that the crouched leg posture may provide greater robustness to changes in terrain height

Heat-conserving postures hinder escape: a thermoregulation–predation trade-off in wintering birds

OpenAIRE

Jennie M. Carr; Steven L. Lima

2012-01-01

Wintering birds may conserve body heat by adopting postures with minimal leg exposure or significant ptiloerection. However, maximally heat-conserving postures may hinder a bird's ability to escape attack, leading to a trade-off between predation risk and thermoregulation. Such a trade-off implies that birds should use the most heat-conserving postures only at very cold temperatures. Feeding in a relatively low-risk environment should also facilitate the use of such heat-conserving postures. ...

Relations between Biomechanical Parameters and Static Power of Arms in Children with Disturbed Posture

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Slobodan Andrašić

2017-02-01

Full Text Available This study is aimed at determining the parameters and biomechanical analysis of their impact on the static arm strength in children with impaired posture as poor kyphotic posture, lordotic poor posture and children with flat feet. A transversal study included a sample of 67 children on the territory of the municipality of Subotica. The structure of the sample is as follows: 22 subjects with impaired kyphotic posture, 18 patients with impaired lordotic posture, and 27 subjects with flat feet. Measuring the level of static arm strength was done by the standardized "folding endurance" test. Observing the morphological development of children with kyphotic, lordotic poor posture and flat feet determined statistically significant differences in biomechanical variables.

POSTURAL CONTROL IN HEALTHY YOUNG ADULTS WITH AND WITHOUT CHRONIC MOTION SENSITIVITY

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Alyahya D

2016-02-01

Full Text Available Background: Postural control requires complex processing of peripheral sensory inputs from the visual, somatosensory and vestibular systems. Motion sensitivity and decreased postural control are influenced by visual-vestibular conflicts.The purpose of this study was to measure the difference between the postural control of healthy adults with and without history of sub-clinical chronic motion sensitivity using a computerized dynamic posturography in a virtual reality environment. Sub-clinical chronic motion sensitivity was operationally defined as a history of avoiding activities causing dizziness, nausea, imbalance, and/or blurred vision without having a related medical diagnosis. Methods: Twenty healthy adults between 22 and 33 years of age participated in the study. Eleven subjects had sub-clinical chronic motion sensitivity and 9 subjects did not. Postural control was measured in both groups using the Bertec Balance Advantage-Dynamic Computerized Dynamic Posturography with Immersion Virtual Reality (CDP-IVR. The CDP-IVR reports an over-all equilibrium score based on subjects’ center of gravity displacement and postural sway while immersed in a virtual reality environment. Subjects were tested on stable (condition 1 and unstable (condition2 platform conditions. Results: There was no significant difference between the two groups in terms of mean age, height, weight, body mass index in kg/m2, postural control scores for conditions 2, and average (p>0.05. However, significant differences were observed in mean postural control for condition 1 between groups (p=0.03. Conclusions: Results of this study suggest that healthy young adults without chronic sub-clinical motion sensitivity have better postural control than those with chronic sub-clinical motion sensitivity. Further investigation is warranted to explore wider age ranges with larger samples sizes as well as intervention strategies to improve postural control.

Effects of posture on postoperative pulmonary function

DEFF Research Database (Denmark)

Nielsen, K G; Holte, Kathrine; Kehlet, H

2003-01-01

BACKGROUND: Pulmonary morbidity is still a relevant complication to major surgery despite improvements in surgical technique and anaesthetic methods. Postoperative posture may be a pathogenic factor, but the effects of changes in postoperative posture on pulmonary function have not been reviewed....... METHODS: Review of controlled, clinical trials evaluating postoperative pulmonary function in patients positioned in the supine vs. the sitting or standing position and patients positioned in the supine vs. the lateral position. Data were obtained from a search in the Medline and Cochrane databases (1966...

Problems of display postures in the Charadrii (Aves: Charadriiformes)

African Journals Online (AJOL)

Studies of displays in the Charadrii (= waders or shorebirds) show that the same posture in different species, even quite closely related, may have a different function in a given context. As a corollary to this, two species even in the same genus may have quite different display postures to convey the same message.

Analysis of Muscle Contraction on Pottery Manufacturing Process Using Electromyography (EMG)

Science.gov (United States)

Soewardi, Hartomo; Azka Rahmayani, Amalia

2016-01-01

One of the most common problems in pottery manufacturing process is musculoskeletal disorders on workers. This disorder was caused by uncomfortable posture where the workers sit on the floor with one leg was folded and another was twisted for long duration. Back, waist, buttock, and right knee frequently experience the disorders. The objective of this research is to investigate the muscle contraction at such body part of workers in manufacturing process of pottery. Electromyography is used to investigate the muscle contraction based on the median frequency signal. Focus measurements is conducted on four muscles types. They are lower interscapular muscle on the right and left side, dorsal lumbar muscle, and lateral hamstring muscle. Statistical analysis is conducted to test differences of muscle contraction between female and male. The result of this research showed that the muscle which reached the highest contraction is dorsal lumbar muscle with the average of median frequency is 51,84 Hz. Then followed by lower interscapular muscle on the left side with the average of median frequency is 31,30 hz, lower interscapular muscle on the right side average of median frequency is 31,24 Hz, and lateral hamstring muscle average of median frequency is 21,77 Hz. Based on the statistic analysis result, there were no differences between male and female on left and right lower interscapular muscle and dorsal lumbar muscle but there were differences on lateral hamstring muscle with the significance level is 5%. Besides that, there were differences for all combination muscle types with the level of significance is 5%.

Body posture measurement in a context of example-based teaching

International Nuclear Information System (INIS)

Benoit, Eric; Perrin, Stephane; Coquin, Didier

2015-01-01

This paper presents a measurement process of body postures operated in a context of humanoid robot learning. The basic measured quantities are the angle joints of a human skeleton and the angle joints of a humanoid robot. Due to the differences between the two mechanical structures, the measurement results are expressed into a common representation space by the way of fuzzy scales. This paper shows how the common representation space can be defined, and presents a method to match weakly defined postures with uncertain measurements of a human posture

Can Postural Instability Respond to Galvanic Vestibular Stimulation in Patients with Parkinson’s Disease?

Directory of Open Access Journals (Sweden)

Hiroshi Kataoka

2016-01-01

Full Text Available Objective Galvanic vestibular stimulation (GVS activates the vestibular afferents, and these changes in vestibular input exert a strong influence on the subject’s posture or standing balance. In patients with Parkinson’s disease (PD, vestibular dysfunction might contribute to postural instability and gait disorders. Methods Current intensity was increased to 0.7 mA, and the current was applied to the patients for 20 minutes. To perform a sham stimulation, the current intensity was increased as described and then decreased to 0 mA over the course of 10 seconds. The patient’s status was recorded continuously for 20 minutes with the patient in the supine position. Results Three out of 5 patients diagnosed with PD with postural instability and/or abnormal axial posture showed a reduction in postural instability after GVS. The score for item 12 of the revised Unified Parkinson’s Disease Rating Scale part 3 was decreased in these patients. Conclusions The mechanism of postural instability is complex and not completely understood. In 2 out of the 5 patients, postural instability was not changed in response to GVS. Nonetheless, the GVS-induced change in postural instability for 3 patients in our study suggests that GVS might be a therapeutic option for postural instability.

Robotic finger perturbation training improves finger postural steadiness and hand dexterity.

Science.gov (United States)

Yoshitake, Yasuhide; Ikeda, Atsutoshi; Shinohara, Minoru

2018-02-01

The purpose of the study was to understand the effect of robotic finger perturbation training on steadiness in finger posture and hand dexterity in healthy young adults. A mobile robotic finger training system was designed to have the functions of high-speed mechanical response, two degrees of freedom, and adjustable loading amplitude and direction. Healthy young adults were assigned to one of the three groups: random perturbation training (RPT), constant force training (CFT), and control. Subjects in RPT and CFT performed steady posture training with their index finger using the robot in different modes: random force in RPT and constant force in CFT. After the 2-week intervention period, fluctuations of the index finger posture decreased only in RPT during steady position-matching tasks with an inertial load. Purdue pegboard test score improved also in RPT only. The relative change in finger postural fluctuations was negatively correlated with the relative change in the number of completed pegs in the pegboard test in RPT. The results indicate that finger posture training with random mechanical perturbations of varying amplitudes and directions of force is effective in improving finger postural steadiness and hand dexterity in healthy young adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Human posture experiments under water: ways of applying the findings to microgravity

Science.gov (United States)

Dirlich, Thomas

For the design and layout human spacecraft interiors the Neutral Body Posture (NBP) in micro-gravity is of great importance. The NBP has been defined as the stable, replicable and nearly constant posture the body "automatically" assumes when a human relaxes in microgravity. Furthermore the NBP, as published, suggests that there is one standard neutral posture for all individuals. Published experiments from space, parabolic flights and under water on the other hand show strong inter-individual variations of neutral (relaxed) postures. This might originate from the quite small sample sizes of subjects analyzed or the different experiment conditions, e. g. space and under water. Since 2008 a collaborative research project focussing on human postures and motions in microgravity has been ongoing at the Technische Univer-sitüt München (TUM). This collaborative effort is undertaken by the Institute of Astronautics a (LRT) and the Institute of Ergonomics (LfE). Several test campaigns have been conducted in simulated microgravity under water using a specially designed standardized experiment setup. Stereo-metric HD video footage and anthropometric data from over 50 subjects (female and male) has been gathered in over 80 experiments. The video data is analyzed using PCMAN software, developed by the LfE, resulting in a 3D volumetric CAD-based model of each subject and posture. Preliminary and ongoing analysis of the data offer evidence for the existence of intra-individually constant neutral postures, as well as continuously recurring relaxation strate-gies. But as with the data published prior the TUM experiments show quite a large variation of inter-individual postures. These variation might be induced or influenced by the special environmental conditions in the underwater experiment. Thus in present paper ways of stan-dardizing data and applying the findings gathered under water to real microgravity are being discussed. The following influences stemming from the

Effects of affective picture viewing on postural control

OpenAIRE

Stins, John F; Beek, Peter J

2007-01-01

Abstract Background Emotion theory holds that unpleasant events prime withdrawal actions, whereas pleasant events prime approach actions. Recent studies have suggested that passive viewing of emotion eliciting images results in postural adjustments, which become manifest as changes in body center of pressure (COP) trajectories. From those studies it appears that posture is modulated most when viewing pictures with negative valence. The present experiment was conducted to test the hypothesis t...

Associations between Tactile Sensory Threshold and Postural Performance and Effects of Healthy Aging and Subthreshold Vibrotactile Stimulation on Postural Outcomes in a Simple Dual Task

Science.gov (United States)

Dettmer, Marius; Pourmoghaddam, Amir; Lee, Beom-Chan; Layne, Charles S.

2016-01-01

Specific activities that require concurrent processing of postural and cognitive tasks may increase the risk for falls in older adults. We investigated whether peripheral receptor sensitivity was associated with postural performance in a dual-task and whether an intervention in form of subthreshold vibration could affect performance. Ten younger (age: 20–35 years) and ten older adults (70–85 years) performed repeated auditory-verbal 1-back tasks while standing quietly on a force platform. Foot sole vibration was randomly added during several trials. Several postural control and performance measures were assessed and statistically analyzed (significance set to α-levels of .05). There were moderate correlations between peripheral sensitivity and several postural performance and control measures (r = .45 to .59). Several postural performance measures differed significantly between older and younger adults (p older adults' performance in dual-tasks, and peripheral sensitivity may be a contributor to the observed differences. A vibration intervention may only be useful when there are more severe impairments of the sensorimotor system. Hence, future research regarding the efficacy of sensorimotor interventions in the form of vibrotactile stimulation should focus on older adults whose balance is significantly affected. PMID:27143967

Sustainable procurement portfolio management: a case study in a mining company

Directory of Open Access Journals (Sweden)

Tamires Magalhães de Mello

Full Text Available Abstract Sustainable procurement is a solution to integrate environmental and social considerations in all steps of procurement process, in order to reduce impacts on human health, environment, and human rights. Despite the existence of important works in this area, more studies for determining how the principles related to sustainable development can be integrated to procurement strategies are needed. This study presents a case study in a mining company to evaluate the elements that should be considered for the implementation of sustainability concept in the contracting of services through the application of a sustainability portfolio model. Results show that the contracts of the internal movement's category of the studied company fit as Strategic Commodity, which means that the items in this category have a risk in the strategic supply, because they need investments made by the buyer in the relationship with the supplier.

Intensive Abdominal Drawing-In Maneuver After Unipedal Postural Stability in Nonathletes With Core Instability

Science.gov (United States)

Lee, Nam G.; You, Joshua (Sung) H.; Kim, Tae H.; Choi, Bong S.

2015-01-01

Context: The exact neuromechanical nature and relative contribution of the abdominal drawing-in maneuver (ADIM) to postural instability warrants further investigation in uninjured and injured populations. Objective: To determine the effects of the ADIM on static core and unipedal postural stability in nonathletes with core instability. Design: Controlled laboratory study. Setting: University research laboratory. Patients or Other Participants: A total of 19 nonathletes (4 women: age = 22.3 ± 1.3 years, height = 164.0 ± 1.7 cm, mass = 56.0 ± 4.6 kg; 15 men: age = 24.6 ± 2.8 years, height = 172.6 ± 4.7 cm, mass = 66.8 ± 7.6 kg) with core instability. Intervention(s): Participants received ADIM training with visual feedback 20 minutes each day for 7 days each week over a 2-week period. Main Outcome Measures(s): Core instability was determined using a prone formal test and measured by a pressure biofeedback unit. Unipedal postural stability was determined by measuring the center-of-pressure sway and associated changes in the abdominal muscle-thickness ratios. Electromyographic activity was measured concurrently in the external oblique, erector spinae, gluteus medius, vastus medialis oblique, tibialis anterior, and medial gastrocnemius muscles. Results: All participants initially were unable to complete the formal test. However, after the 2-week ADIM training period, all participants were able to reduce the pressure biofeedback unit by a range of 4 to 10 mm Hg from an initial 70 mm Hg and maintain it at 60 to 66 mm Hg with minimal activation of the external oblique (t18 = 3.691, P = .002) and erector spinae (t18 = 2.823, P = .01) muscles. Monitoring of the pressure biofeedback unit and other muscle activations confirmed that the correct muscle contraction defining the ADIM was accomplished. This core stabilization was well maintained in the unipedal-stance position, as evidenced by a decrease in the center-of-pressure sway measures (t18 range, 3.953–5.775, P

Postural Control in Workplace Safety: Role of Occupational Footwear and Workload

OpenAIRE

Harish Chander; John C. Garner; Chip Wade; Adam C. Knight

2017-01-01

Maintaining postural stability is crucial, especially in hazardous occupational environments. The purpose of the study was to assess the role of three occupational footwear (low top shoe (LT); tactical work boot (TB) and steel-toed work boot (WB)) on postural stability when exposed to an occupational workload (4-h) involving standing/walking using the sensory organization test (SOT) equilibrium (EQ) scores and comparing current results with previously published postural sway variables from th...

Photographic measurement of head and cervical posture when viewing mobile phone: a pilot study.

Science.gov (United States)

Guan, Xiaofei; Fan, Guoxin; Wu, Xinbo; Zeng, Ying; Su, Hang; Gu, Guangfei; Zhou, Qi; Gu, Xin; Zhang, Hailong; He, Shisheng

2015-12-01

With the dramatic growth of mobile phone usage, concerns have been raised with regard to the adverse health effects of mobile phone on spinal posture. The aim of this study was to determine the head and cervical postures by photogrammetry when viewing the mobile phone screen, compared with those in neutral standing posture. A total of 186 subjects (81 females and 105 males) aged from 17 to 31 years old participated in this study. Subjects were instructed to stand neutrally and using mobile phone as in daily life. Using a photographic method, the sagittal head and cervical postures were assessed by head tilt angle, neck tilt angle, forward head shift and gaze angle. The photographic method showed a high intra-rater and inter-rater reliability in measuring the sagittal posture of cervical spine and gaze angle (ICCs ranged from 0.80 to 0.99). When looking at mobile phone, the head tilt angle significantly increased (from 74.55° to 95.22°, p = 0.000) and the neck angle decreased (from 54.68° to 38.77°, p = 0.000). The forward head posture was also confirmed by the significantly increased head shift (from 10.90 to 13.85 cm, p = 0.000). The posture assumed in mobile phone use was significantly correlated with neutral posture (p phone use. Compared to neutral standing, subjects display a more forward head posture when viewing the mobile phone screen, which is correlated with neutral posture, gaze angle and gender. Future studies will be needed to investigate a dose-response relationship between mobile phone use and assumed posture.

Models of Postural Control: Shared Variance in Joint and COM Motions.

Directory of Open Access Journals (Sweden)

Melissa C Kilby

Full Text Available This paper investigated the organization of the postural control system in human upright stance. To this aim the shared variance between joint and 3D total body center of mass (COM motions was analyzed using multivariate canonical correlation analysis (CCA. The CCA was performed as a function of established models of postural control that varied in their joint degrees of freedom (DOF, namely, an inverted pendulum ankle model (2DOF, ankle-hip model (4DOF, ankle-knee-hip model (5DOF, and ankle-knee-hip-neck model (7DOF. Healthy young adults performed various postural tasks (two-leg and one-leg quiet stances, voluntary AP and ML sway on a foam and rigid surface of support. Based on CCA model selection procedures, the amount of shared variance between joint and 3D COM motions and the cross-loading patterns we provide direct evidence of the contribution of multi-DOF postural control mechanisms to human balance. The direct model fitting of CCA showed that incrementing the DOFs in the model through to 7DOF was associated with progressively enhanced shared variance with COM motion. In the 7DOF model, the first canonical function revealed more active involvement of all joints during more challenging one leg stances and dynamic posture tasks. Furthermore, the shared variance was enhanced during the dynamic posture conditions, consistent with a reduction of dimension. This set of outcomes shows directly the degeneracy of multivariate joint regulation in postural control that is influenced by stance and surface of support conditions.

Forearm posture and mobility in quadrupedal dinosaurs.

Science.gov (United States)

VanBuren, Collin S; Bonnan, Matthew

2013-01-01

Quadrupedality evolved four independent times in dinosaurs; however, the constraints associated with these transitions in limb anatomy and function remain poorly understood, in particular the evolution of forearm posture and rotational ability (i.e., active pronation and supination). Results of previous qualitative studies are inconsistent, likely due to an inability to quantitatively assess the likelihood of their conclusions. We attempt to quantify antebrachial posture and mobility using the radius bone because its morphology is distinct between extant sprawled taxa with a limited active pronation ability and parasagittal taxa that have an enhanced ability to actively pronate the manus. We used a sliding semi-landmark, outline-based geometric morphometric approach of the proximal radial head and a measurement of the angle of curvature of the radius in a sample of 189 mammals, 49 dinosaurs, 35 squamates, 16 birds, and 5 crocodilians. Our results of radial head morphology showed that quadrupedal ceratopsians, bipedal non-hadrosaurid ornithopods, and theropods had limited pronation/supination ability, and sauropodomorphs have unique radial head morphology that likely allowed limited rotational ability. However, the curvature of the radius showed that no dinosaurian clade had the ability to cross the radius about the ulna, suggesting parallel antebrachial elements for all quadrupedal dinosaurs. We conclude that the bipedal origins of all quadrupedal dinosaur clades could have allowed for greater disparity in forelimb posture than previously appreciated, and future studies on dinosaur posture should not limit their classifications to the overly simplistic extant dichotomy.

Influence of musical groove on postural sway.

Science.gov (United States)

Ross, Jessica M; Warlaumont, Anne S; Abney, Drew H; Rigoli, Lillian M; Balasubramaniam, Ramesh

2016-03-01

Timescales of postural fluctuation reflect underlying neuromuscular processes in balance control that are influenced by sensory information and the performance of concurrent cognitive and motor tasks. An open question is how postural fluctuations entrain to complex environmental rhythms, such as in music, which also vary on multiple timescales. Musical groove describes the property of music that encourages auditory-motor synchronization and is used to study voluntary motor entrainment to rhythmic sounds. The influence of groove on balance control mechanisms remains unexplored. We recorded fluctuations in center of pressure (CoP) of standing participants (N = 40) listening to low and high groove music and during quiet stance. We found an effect of musical groove on radial sway variability, with the least amount of variability in the high groove condition. In addition, we observed that groove influenced postural sway entrainment at various temporal scales. For example, with increasing levels of groove, we observed more entrainment to shorter, local timescale rhythmic musical occurrences. In contrast, we observed more entrainment to longer, global timescale features of the music, such as periodicity, with decreasing levels of groove. Finally, musical experience influenced the amount of postural variability and entrainment at local and global timescales. We conclude that groove in music and musical experience can influence the neural mechanisms that govern balance control, and discuss implications of our findings in terms of multiscale sensorimotor coupling. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Forearm posture and mobility in quadrupedal dinosaurs.

Directory of Open Access Journals (Sweden)

Collin S VanBuren

Full Text Available Quadrupedality evolved four independent times in dinosaurs; however, the constraints associated with these transitions in limb anatomy and function remain poorly understood, in particular the evolution of forearm posture and rotational ability (i.e., active pronation and supination. Results of previous qualitative studies are inconsistent, likely due to an inability to quantitatively assess the likelihood of their conclusions. We attempt to quantify antebrachial posture and mobility using the radius bone because its morphology is distinct between extant sprawled taxa with a limited active pronation ability and parasagittal taxa that have an enhanced ability to actively pronate the manus. We used a sliding semi-landmark, outline-based geometric morphometric approach of the proximal radial head and a measurement of the angle of curvature of the radius in a sample of 189 mammals, 49 dinosaurs, 35 squamates, 16 birds, and 5 crocodilians. Our results of radial head morphology showed that quadrupedal ceratopsians, bipedal non-hadrosaurid ornithopods, and theropods had limited pronation/supination ability, and sauropodomorphs have unique radial head morphology that likely allowed limited rotational ability. However, the curvature of the radius showed that no dinosaurian clade had the ability to cross the radius about the ulna, suggesting parallel antebrachial elements for all quadrupedal dinosaurs. We conclude that the bipedal origins of all quadrupedal dinosaur clades could have allowed for greater disparity in forelimb posture than previously appreciated, and future studies on dinosaur posture should not limit their classifications to the overly simplistic extant dichotomy.

Collective hydrodynamic communication through ultra-fast contractions

Science.gov (United States)

Bhamla, Saad; Mathijssen, Arnold; Prakash, Manu

2017-11-01

The biophysical relationships between physiological sensors and actuators were fundamental to the development of early life forms, as responding to external stimuli promptly is key to survival. We study an unusual protist Spirostomum ambiguum, a single-celled organism that can grow up to 4mm in size, visible to the naked eye, as a model system for impulsive systems. Coiling its cytoskeleton, this ciliate can contract its long body within milliseconds, one of the fastest accelerations known in cell biology. We demonstrate that these rapid contractions generate long-ranged vortex flows that can trigger other cells to contract, repeatedly, which collectively leads to an ultra-fast hydrodynamic signal transduction across a colony that moves hundreds of times faster than the swimming speed. By combining high-speed PIV experiments and analytical modelling we determine the critical rheosensitivity required to sustain these signal waves. Whereas the biological motive is not fully understood, contractions are known to release toxins from membrane-bound extrusomes, thus we hypothesize that synchronised discharges could facilitate the repulsion of large-scale predators cooperatively. Please also see our other talk ``Rheosensing by impulsive cells at intermediate Reynolds numbers''.

Cephalic version by postural management for breech presentation.

Science.gov (United States)

Hofmeyr, G Justus; Kulier, Regina

2012-10-17

Babies with breech presentation (bottom first) are at increased risk of complications during birth, and are often delivered by caesarean section. The chance of breech presentation persisting at the time of delivery, and the risk of caesarean section, can be reduced by external cephalic version (ECV - turning the baby by manual manipulation through the mother's abdomen). It is also possible that maternal posture may influence fetal position. Many postural techniques have been used to promote cephalic version. The objective of this review was to assess the effects of postural management of breech presentation on measures of pregnancy outcome. We evaluated procedures in which the mother rests with her pelvis elevated. These include the knee-chest position, and a supine position with the pelvis elevated with a wedge-shaped cushion. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (22 August 2012). Randomised and quasi-randomised trials comparing postural management with pelvic elevation for breech presentation, with a control group. One or both review authors assessed eligibility and trial quality. We have included six studies involving a total of 417 women. The rates for non-cephalic births, Cesarean section and Apgar scores below 7 at one minute, regardless of whether ECV was attempted or not, were similar between the intervention and control groups (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.84 to 1.15; RR 1.10; 95% CI 0.89 to 1.37; RR 0.88; 95% CI 0.50 to 1.55). There is insufficient evidence from well-controlled trials to support the use of postural management for breech presentation. The numbers of women studied to date remain relatively small. Further research is needed.

Closed loop kinesthetic feedback for postural control rehabilitation.

Science.gov (United States)

Vérité, Fabien; Bachta, Wael; Morel, Guillaume

2014-01-01

Postural control rehabilitation may benefit from the use of smart devices providing biofeedback. This approach consists of increasing the patients perception of their postural state. Namely, postural state is monitored and fed back in real time to the patients through one or more sensory channels. This allows implementing rehabilitation exercises where the patients control their posture with the help of additional sensory inputs. In this paper, a closed loop control of the Center-Of-Pressure (CoP) based on kinesthetic feedback is proposed as a new form of biofeedback. The motion of a one Degree of Freedom (DoF) translational device, lightly touched by the patient's forefinger, is servoed to the patient's CoP position extracted from the measurements of a force plate on which he/she stands. As a result, the patient's CoP can be controllably displaced. A first set of experiments is used to prove the feasibility of this closed-loop control under ideal conditions favoring the perception of the kinesthetic feedback, while the subject is totally unaware of the context. A second set of experiments is then proposed to evaluate the robustness of this approach under experimental conditions that are more realistic with regards to the clinical context of a rehabilitation program involving biofeedback-based exercises.

Body posture in the sagittal plane and scoliotic variables in girls aged 7-18

Directory of Open Access Journals (Sweden)

Jacek Wilczyński

2018-02-01

Introduction. The aim of the study was to analyze the correlation between the variable posture in the sagittal plane and the scoliotic variables. Material and methods. The study involved 28 girls aged 7-18 years with scoliotic posture and scoliosis. Body posture as well as the spine were examined using Moiré’s spatial photogrammetry and the Exhibeon digital radiography method. Based on the size of the spinal curvature, the following were distinguished: scoliotic postures: 1-9° and scoliosis: ≥10°. Results. There were 21 (75% with scoliotic posture and 7 (25% with scoliosis. The size of the thoracic kyphosis and lumbar lordosis was normal. Conclusions. Between the body postural variables in the sagittal plane and the scoliotic variables, both positive (direct proportional and negative (inversely proportional correlations occurred. In the selection of scoliosis treatment method, the size of the postural variables in the sagittal plane should be taken into account, and each patient’s case should be individually considered.

Dynamic postural control and associated attentional demands in contemporary dancers versus non-dancers.

Science.gov (United States)

Sirois-Leclerc, Geneviève; Remaud, Anthony; Bilodeau, Martin

2017-01-01

Postural control is not a fully automatic process, but requires a certain level of attention, particularly as the difficulty of the postural task increases. This study aimed at testing whether experienced contemporary dancers, because of their specialized training involving the control of posture/balance, would present with a dual-task performance suggesting lesser attentional demands associated with dynamic postural control compared with non-dancers. Twenty dancers and 16 non-dancers performed a dynamic postural tracking task in both antero-posterior and side-to-side directions, while standing on a force platform. The postural task was performed, in turn, 1) as a stand-alone task, and concurrently with both 2) a simple reaction time task and 3) a choice reaction time task. Postural control performance was estimated through variables calculated from centre of pressure movements. Although no overall group difference was found in reaction time values, we found a better ability to control the side to side movements of the centre of pressure during the tracking task in dancers compared with non-dancers, which was dependent on the secondary task. This suggests that such increased ability is influenced by available attentional resources.

Dynamic postural control and associated attentional demands in contemporary dancers versus non-dancers.

Directory of Open Access Journals (Sweden)

Geneviève Sirois-Leclerc

Full Text Available Postural control is not a fully automatic process, but requires a certain level of attention, particularly as the difficulty of the postural task increases. This study aimed at testing whether experienced contemporary dancers, because of their specialized training involving the control of posture/balance, would present with a dual-task performance suggesting lesser attentional demands associated with dynamic postural control compared with non-dancers. Twenty dancers and 16 non-dancers performed a dynamic postural tracking task in both antero-posterior and side-to-side directions, while standing on a force platform. The postural task was performed, in turn, 1 as a stand-alone task, and concurrently with both 2 a simple reaction time task and 3 a choice reaction time task. Postural control performance was estimated through variables calculated from centre of pressure movements. Although no overall group difference was found in reaction time values, we found a better ability to control the side to side movements of the centre of pressure during the tracking task in dancers compared with non-dancers, which was dependent on the secondary task. This suggests that such increased ability is influenced by available attentional resources.

Feeding and resting postures of wild northern muriquis (Brachyteles hypoxanthus).

Science.gov (United States)

Iurck, Maria F; Nowak, Matthew G; Costa, Leny C M; Mendes, Sérgio L; Ford, Susan M; Strier, Karen B

2013-01-01

Increased body size in Brachyteles has been regarded as an important evolutionary adaptation that allowed a greater reliance on leaves compared to other more frugivorous Atelidae, but its association with muriqui positional behavior and substrate use is still unknown. Here, we present original data on the feeding and resting postures of the northern muriqui (Brachyteles hypoxanthus) and evaluate predictions about the relationships between body size, postural behavior, and substrate use derived from previously published data for other atelids (e.g. Alouatta, Ateles, and Lagothrix). The study was undertaken from August 2002 to July 2003 on a large group of well-habituated muriquis inhabiting the Reserva Particular do Patrimônio Natural - Felíciano Miguel Abdala in Minas Gerais, Brazil. Consistent with our predictions, we found that B. hypoxanthus was highly suspensory during postural feeding (60.9%) and commonly used tail-hind limb suspension/horizontal tripod (38.0%) or tail-forelimb/hind limb suspension (21.4%). However, although tail-suspensory postures permitted the muriquis to use the terminal canopy and small-sized substrates, these areas were also accessed via tail-assisted above-branch postural behaviors involving multiple substrates. Unexpectedly, tail-suspensory postures were found to be frequently associated with large substrates, tree trunks, and the understory. We suggest that Brachyteles' ability to access food resources from all areas of a feeding tree and from tree crowns at different canopy levels may account for their ability to efficiently exploit food resources in seasonal disturbed forest fragments of the Brazilian Atlantic Forest today. © 2012 Wiley Periodicals, Inc.

Contract theory and EU Contract Law

NARCIS (Netherlands)

Hesselink, M.W.; Twigg-Flesner, C.

2016-01-01

This paper explores the relationship between contract theory and European contract law. In particular, it confronts the leading contract law theories with the main characteristics of EU contract law. The conclusion is that the two do not match well. In particular, monist normative contract theories

Motor deficits in schizophrenia quantified by nonlinear analysis of postural sway.

Directory of Open Access Journals (Sweden)

Jerillyn S Kent

Full Text Available Motor dysfunction is a consistently reported but understudied aspect of schizophrenia. Postural sway area was examined in individuals with schizophrenia under four conditions with different amounts of visual and proprioceptive feedback: eyes open or closed and feet together or shoulder width apart. The nonlinear complexity of postural sway was assessed by detrended fluctuation analysis (DFA. The schizophrenia group (n = 27 exhibited greater sway area compared to controls (n = 37. Participants with schizophrenia showed increased sway area following the removal of visual input, while this pattern was absent in controls. Examination of DFA revealed decreased complexity of postural sway and abnormal changes in complexity upon removal of visual input in individuals with schizophrenia. Additionally, less complex postural sway was associated with increased symptom severity in participants with schizophrenia. Given the critical involvement of the cerebellum and related circuits in postural stability and sensorimotor integration, these results are consistent with growing evidence of motor, cerebellar, and sensory integration dysfunction in the disorder, and with theoretical models that implicate cerebellar deficits and more general disconnection of function in schizophrenia.

Postural control in restless legs syndrome with medication intervention using pramipexole.

Science.gov (United States)

Ahlgrén-Rimpiläinen, Aulikki; Lauerma, Hannu; Kähkönen, Seppo; Aalto, Heikki; Tuisku, Katinka; Holi, Matti; Pyykkö, Ilmari; Rimpiläinen, Ilpo

2014-02-01

Central dopamine regulation is involved in postural control and in the pathophysiology of restless legs syndrome (RLS) and Parkinson's disease (PD). Postural control abnormalities have been detected in PD, but there are no earlier studies with regard to RLS and postural control. Computerized force platform posturography was applied to measure the shift and the velocity (CPFV) of center point of forces (CPF) with eyes open (EO) and eyes closed (EC) in controls (n = 12) and prior and after a single day intervention with pramipexole in RLS subjects (n = 12). CPFV (EO) was significantly lower in the RLS group (p < 0.05) than in controls. After pramipexole intake, the difference disappeared and the subjective symptom severity diminished. Pramipexole did not significantly influence CPFV (EC) or CPF shift direction. Subjects with RLS used extensively visual mechanisms to control vestibule-spinal reflexes to improve or compensate the postural stability. Further research is needed to clarify altered feedback in the central nervous system and involvement of dopamine and vision in the postural control in RLS.

Posture-based processing in visual short-term memory for actions.

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Vicary, Staci A; Stevens, Catherine J

2014-01-01

Visual perception of human action involves both form and motion processing, which may rely on partially dissociable neural networks. If form and motion are dissociable during visual perception, then they may also be dissociable during their retention in visual short-term memory (VSTM). To elicit form-plus-motion and form-only processing of dance-like actions, individual action frames can be presented in the correct or incorrect order. The former appears coherent and should elicit action perception, engaging both form and motion pathways, whereas the latter appears incoherent and should elicit posture perception, engaging form pathways alone. It was hypothesized that, if form and motion are dissociable in VSTM, then recognition of static body posture should be better after viewing incoherent than after viewing coherent actions. However, as VSTM is capacity limited, posture-based encoding of actions may be ineffective with increased number of items or frames. Using a behavioural change detection task, recognition of a single test posture was significantly more likely after studying incoherent than after studying coherent stimuli. However, this effect only occurred for spans of two (but not three) items and for stimuli with five (but not nine) frames. As in perception, posture and motion are dissociable in VSTM.

Musculoskeletal pain and posture decrease step length in young adults

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Maria Regina Rachmawati

2009-08-01

Full Text Available Pain of the musculoskeletal system, especially low back pain, is one of the most frequent problems with a high risk of disability. The aim of this research study was to determine the existence of an association between low back pain on one hand, posture and step length on the other. This cross-sectional study was conducted on 77 healthy young adult subjects. Step length was measured with the Biodex Gait Trainer 2 (230 VAC. The study results indicate that 62.3% of the young adult subjects had suffered from low back pain. There was no significant association between gender and pain. In male subjects no significant association was found between pain on one hand and mean difference in step length and posture on the other. However, in female subjects with abnormal posture, there was a highly significant difference in left step length between subjects with back pain and those without (p=0.007. The results of a multiple regression analysis indicate that posture has the greatest influence on left step length (B=4.135; 95% Confidence Interval 0.292-7.977. It is recommended that in the examination of low back pain an assessment be made of posture, step length and difference in step lengths.

Musculoskeletal pain and posture decrease step length in young adults

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Maria Regina Rachmawati

2016-02-01

Full Text Available Pain of the musculoskeletal system, especially low back pain, is one of the most frequent problems with a high risk of disability. The aim of this research study was to determine the existence of an association between low back pain on one hand,  posture and step length on the other. This cross-sectional study was conducted on 77 healthy young adult subjects. Step length was measured with the Biodex Gait Trainer 2 (230 VAC. The study results indicate that 62.3% of the young adult subjects had suffered from low back pain. There was no significant association between gender and pain. In male subjects no significant association was found between pain on one hand and mean difference in step length and posture on the other. However, in female subjects with abnormal posture, there was a highly significant difference in left step length between subjects with back pain and those without (p=0.007.  The results of a multiple regression analysis indicate that posture has the greatest influence on left step length (B=4.135; 95% Confidence Interval 0.292-7.977. It is recommended that in the examination of low back pain an assessment be made of posture, step length and difference in step lengths.

Comparison of posture among adolescent male volleyball players and non-athletes

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Małgorzata Grabara

2014-11-01

Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

Comparison of posture among adolescent male volleyball players and non-athlete

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Małgorzata Grabara

2014-10-01

Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

Comparison of posture among adolescent male volleyball players and non-athletes

Science.gov (United States)

2014-01-01

Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified. PMID:25729154

Postural Control in Workplace Safety: Role of Occupational Footwear and Workload

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Harish Chander

2017-08-01

Full Text Available Maintaining postural stability is crucial, especially in hazardous occupational environments. The purpose of the study was to assess the role of three occupational footwear (low top shoe (LT; tactical work boot (TB and steel-toed work boot (WB on postural stability when exposed to an occupational workload (4-h involving standing/walking using the sensory organization test (SOT equilibrium (EQ scores and comparing current results with previously published postural sway variables from the same study. Fourteen male adults were tested on three separate days wearing a randomized occupational footwear, at the beginning (pre and every 30 min of the 4-h workload until 240th min. SOT EQ scores were analyzed using a 3 × 9 repeated measures analysis of variance at an alpha level of 0.05. Significant differences between footwear was found in eyes open (p = 0.03 and eyes closed (p = 0.001 conditions. Pairwise comparisons revealed that LT had significantly lower postural stability compared to TB and WB. No other significant differences were found between footwear and over time. Significant differences between footwear can be attributed to design characteristics of footwear. Lack of significant differences over time suggests that, even though the average EQ scores decreased during the workload implying less postural stability, SOT EQ scores alone may not be sufficient to detect postural stability changes over the 4-h workload.

Age-related differences in muscle fatigue vary by contraction type: a meta-analysis.

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Avin, Keith G; Law, Laura A Frey

2011-08-01

During senescence, despite the loss of strength (force-generating capability) associated with sarcopenia, muscle endurance may improve for isometric contractions. The purpose of this study was to perform a systematic meta-analysis of young versus older adults, considering likely moderators (ie, contraction type, joint, sex, activity level, and task intensity). A 2-stage systematic review identified potential studies from PubMed, CINAHL, PEDro, EBSCOhost: ERIC, EBSCOhost: Sportdiscus, and The Cochrane Library. Studies reporting fatigue tasks (voluntary activation) performed at a relative intensity in both young (18-45 years of age) and old (≥ 55 years of age) adults who were healthy were considered. Sample size, mean and variance outcome data (ie, fatigue index or endurance time), joint, contraction type, task intensity (percentage of maximum), sex, and activity levels were extracted. Effect sizes were (1) computed for all data points; (2) subgrouped by contraction type, sex, joint or muscle group, intensity, or activity level; and (3) further subgrouped between contraction type and the remaining moderators. Out of 3,457 potential studies, 46 publications (with 78 distinct effect size data points) met all inclusion criteria. A lack of available data limited subgroup analyses (ie, sex, intensity, joint), as did a disproportionate spread of data (most intensities ≥ 50% of maximum voluntary contraction). Overall, older adults were able to sustain relative-intensity tasks significantly longer or with less force decay than younger adults (effect size=0.49). However, this age-related difference was present only for sustained and intermittent isometric contractions, whereas this age-related advantage was lost for dynamic tasks. When controlling for contraction type, the additional modifiers played minor roles. Identifying muscle endurance capabilities in the older adult may provide an avenue to improve functional capabilities, despite a clearly established decrement in

Hand posture effects on handedness recognition as revealed by the Simon effect

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Allan P Lameira

2009-11-01

Full Text Available We investigated the influence of hand posture in handedness recognition, while varying the spatial correspondence between stimulus and response in a modified Simon task. Drawings of the left and right hands were displayed either in a back or palm view while participants discriminated stimulus handedness by pressing left/right keys with their hands resting either in a prone or supine posture. As a control, subjects performed a regular Simon task using simple geometric shapes as stimuli. Results showed that when hands were in a prone posture, the spatially corresponding trials (i.e., stimulus and response located on the same side were faster than the non-corresponding trials (i.e., stimulus and response on opposite sides. In contrast, for the supine posture, there was no difference between corresponding and non-corresponding trials. The control experiment with the regular Simon task showed that the posture of the responding hand had no influence on performance. When the stimulus is the drawing of a hand, however, the posture of the responding hand affects the spatial correspondence effect because response location is coded based on multiple reference points, including the body of the hand.

Differences in postural disturbances between female adolescents handball players and nontraining peers.

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Jandrić, Slavica Đ

2016-04-01

Physical activity and sport can influence the extent of the presence of the postural disturbances in children. The aim of this study was to investigate the occurrence of differences in the postural disturbances in female adolescents in relation to team handball training. This investigation involved 150 female adolescents with the average age of 13.4 ± 1.5 years divided into two groups (50 adolescents trained handball and 100 did non train it). The study determined a statistically significant difference in the total number of postural disturbances between the two groups of adolescents (p 0.05). Handball adolescents players have less postural disturbances than untrained adolescents. Flat foot is significantly less frequent in female adolescents handball players than in untrained ones. Findings obtained in this investigation can help us in planning continuous prevention, observation and care for untrained and trained team handball female adolescents with postural disturbances.

Physical activity limits the effects of age and Alzheimer's disease on postural control.

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Debove, Lola; Bru, Noelle; Couderc, Martine; Noé, Frederic; Paillard, Thierry

2017-09-01

The aim was to study the possible influence of physical activity on the postural performance of subjects with Alzheimer's disease (AD). The postural performance (i.e. surface area of the center of foot pressure displacement) of 3 groups was compared: Alzheimer active group (AA), Alzheimer non-active group (ANA) and healthy non-active group (HNA). The AA group's postural performance was superior to that of the ANA and HNA groups. AD disturbed postural performance but participation in regular physical activity made it possible to limit the disturbing effects of AD to a surprising extent, since the postural performance of active AD subjects was also superior to that of healthy subjects. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The Effect of Local Fatigue Induced at Proximal and Distal Muscles of Lower Extremity in Sagittal Plane on Visual Dependency in Quiet Standing Postural Stability of Healthy Young Females

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Manijeh Soleymani-Far

2007-10-01

Full Text Available Objective: The purpose of the present study was to assess the effect of local muscle fatigue induced at proximal and distal segments of lower extremity on sagittal plane mover on visual dependency in quiet standing postural stability. Materials & Methods: In this Quasi–experimental study (before – after comparison sagittal plane prime movers of the ankle and hip musculature were fatigued using isokinetic contractions at two test sessions with a randomized order and one week interval. Twenty five healthy young female students were َselected by using non probability selection and sample of convenience and asked to maintain single leg upright posture as immobile as possible. RMS and SD of Center of Pressure displacements were assessed in 30 seconds and consequently, the eyes were closed after 15 seconds. A analysis of variance (ANOVA for repeated measures was used to analyze the effect of the following factors over two periods of 5 seconds immediately before and after eye closure: (1 fatigue, (2 vision, (3 segment of fatigue. Results: The main effects of each within-subject factors (fatigue, vision and segment of fatigue were significant (P<0.05. The analysis of RMS and SD of Center of Pressure demonstrated a significant interaction between fatigue and vision, and fatigue and segment of fatigue so that the effects of Fatigue on Proximal segment and eye closed conditions were increased. Conclusion: The visual dependency for control of postural stability incremented following muscle fatigue. Proximal muscle fatigue lead to exaggeration of visual dependency for control of postural stability. Based on the present results, emphasis on the proprioception of proximal segment of lower extremity may be recommended for postural stability training.

Posture and lumbar puncture headache: a controlled trial in 50 patients.

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Handler, C E; Smith, F R; Perkin, G D; Rose, F C

1982-01-01

A prospective single blind trial in 50 patients was performed to investigate the effect of posture on post lumbar puncture headache (LPH). A difference between the frequency of headache at five hours between the two groups (prone for four hours, versus 30 degrees head down tilt for 30 minutes followed by supine posture for 3 1/2 hours) did not reach significance. These findings do not support the suggestion that a prone posture, by possibly reducing cerebrospinal fluid (CSF) leakage, signific...

Postural control of small for gestational age infants born at term Controle postural de lactentes nascidos a termo pequenos para a idade gestacional

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D Campos

2007-02-01

Full Text Available OBJECTIVE: This study compared the postural control of small (SGA and appropriate (AGA for gestational age infants born at term, at the ages of 3, 6, 9 and 12 months. METHOD: This was a cohort study of infants born at term, with birth weight less than the 10th percentile for the SGA group and between the 10th and 90th percentiles for the AGA group. Infants with genetic syndromes, malformations, congenital infections and internment in neonatal intensive care unit were excluded. The evaluation instrument was the Alberta Infant Motor Scale. RESULTS: Comparison of the SGA and AGA groups did not show any significant differences (p>0.05 at the assessment times. However, the postural control of the SGA group was influenced by the gestational age (r=-0.83; p= 0.006 and 5th minute Apgar (r= 0.79; p= 0.01 in the 3rd month, and by maternal occupation (r= 0.67; p= 0.01 in the 6th month. CONCLUSION: It was concluded that the postural control was similar in the groups. However, the postural control of the SGA group was influenced by biological and environmental factors.OBJETIVO: Este estudo teve por objetivo comparar o controle postural de lactentes nascidos a termo, pequenos (PIG e adequados para a idade gestacional (AIG nos 3º, 6º, 9º e 12º meses. MÉTODO: Estudo longitudinal de lactentes nascidos a termo, com peso de nascimento menor que o percentil 10 para o grupo PIG e entre o percentil 10 e 90 para o grupo AIG. Síndromes genéticas, más-formações, infecções congênitas e internados em unidade de terapia intensiva neonatal foram excluídos. O instrumento de avaliação foi Alberta Infant Motor Scale. RESULTADOS: A comparação do grupo PIG e AIG não mostrou diferença significativa (p> 0,05 nos meses avaliados. Entretanto, o controle postural do grupo PIG foi influenciado pela idade gestacional (r= -0,83/p= 0,006 e Apgar de 5' (r= 0,79/p= 0,01 no 3º mês; e pela ocupação materna (r= 0,67/p= 0,01 no 6º mês. CONCLUSÃO: Concluiu-se que o

Associations between Tactile Sensory Threshold and Postural Performance and Effects of Healthy Aging and Subthreshold Vibrotactile Stimulation on Postural Outcomes in a Simple Dual Task

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Marius Dettmer

2016-01-01

Full Text Available Specific activities that require concurrent processing of postural and cognitive tasks may increase the risk for falls in older adults. We investigated whether peripheral receptor sensitivity was associated with postural performance in a dual-task and whether an intervention in form of subthreshold vibration could affect performance. Ten younger (age: 20–35 years and ten older adults (70–85 years performed repeated auditory-verbal 1-back tasks while standing quietly on a force platform. Foot sole vibration was randomly added during several trials. Several postural control and performance measures were assessed and statistically analyzed (significance set to α-levels of .05. There were moderate correlations between peripheral sensitivity and several postural performance and control measures (r=.45 to .59. Several postural performance measures differed significantly between older and younger adults (p<0.05; addition of vibration did not affect outcome measures. Aging affects healthy older adults’ performance in dual-tasks, and peripheral sensitivity may be a contributor to the observed differences. A vibration intervention may only be useful when there are more severe impairments of the sensorimotor system. Hence, future research regarding the efficacy of sensorimotor interventions in the form of vibrotactile stimulation should focus on older adults whose balance is significantly affected.

Postural stability changes in the elderly with cataract simulation and refractive blur.

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Anand, Vijay; Buckley, John G; Scally, Andy; Elliott, David B

2003-11-01

To determine the influence of cataractous and refractive blur on postural stability and limb-load asymmetry (LLA) and to establish how postural stability changes with the spatial frequency and contrast of the visual stimulus. Thirteen elderly subjects (mean age, 70.76 +/- 4.14 [SD] years) with no history of falls and normal vision were recruited. Postural stability was determined as the root mean square [RMS] of the center of pressure (COP) signal in the anterior-posterior (A-P) and medial-lateral directions and LLA was determined as the ratio of the average body weight placed on the more-loaded limb to the less-loaded limb, recorded during a 30-second period. Data were collected under normal standing conditions and with somatosensory system input disrupted. Measurements were repeated with four visual targets with high (8 cyc/deg) or low (2 cyc/deg) spatial frequency and high (Weber contrast, approximately 95%) or low (Weber contrast, approximately 25%) contrast. Postural stability was measured under conditions of binocular refractive blur of 0, 1, 2, 4, and 8 D and with cataract simulation. The data were analyzed in a population-averaged linear model. The cataract simulation caused significant increases in postural instability equivalent to that caused by 8-D blur conditions, and its effect was greater when the input from the somatosensory system was disrupted. High spatial frequency targets increased postural instability. Refractive blur, cataract simulation, or eye closure had no effect on LLA. Findings indicate that cataractous and refractive blur increase postural instability, and show why the elderly, many of whom have poor vision along with musculoskeletal and central nervous system degeneration, are at greater risk of falling. Findings also highlight that changes in contrast sensitivity rather than resolution changes are responsible for increasing postural instability. Providing low spatial frequency information in certain environments may be useful in

Effects of hippotherapy on posture in individuals with Down Syndrome

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Ana Paula Espindula

Full Text Available Abstract Introduction: Individuals with Down syndrome (DS have alterations that affect the musculoskeletal system, causing abnormal patterns, and alter the morphological anatomical and mechanical axes that provide intrinsic stability to the skeleton, and can trigger misalignments and orthopedic disorders in adulthood. Objective: The objective of student to evaluate posture and postural alignment before and after the hippotherapyin individuals with DS. Methods: Posture of five individuals with DS was evaluated by the software SAPO before and after 27 sessions the hippotherapy. Data were subjected to qualitative descriptive analysis using cluster and statistical analysis with the aid of the software Sigma Stat 2.0, considering differences as statistically significant at p-value < 5%. Results: Improvements were achieved for the alignment of shoulder, head, hip, and lower limbs, in addition to decrease in kyphosis and head protrusion. Conclusion: Patients with DS demonstrated satisfactory changes in motor behavior reflected in improved static posture after treatment with hippotherapy.

Comparing postural balance among older adults and Parkinson's disease patients

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Isabela Andrelino de Almeida

Full Text Available ABSTRACT The objective of this study was to compare postural balance among healthy older adults and Parkinson's disease (PD patients during one-legged stance balance. We recruited 36 individuals of both sexes and divided them into two groups: healthy older adults (HG, and individuals with PD (PG. All the participants were assessed through a single-leg balance test, with eyes open, during 30 seconds (30 seconds of rest across trials on a force platform. Balance parameters were computed from mean across trials to quantify postural control: center of pressure (COP area and mean velocity in both directions of movement, anterior-posterior and medial-lateral. Significant differences between-group were reported for area of COP (P=0.002 and mean velocity in anterior-posterior direction (P=0.037, where poor postural control was related to PD patients rather than to healthy individuals. One-legged stance balance was a sensitive task used to discriminate poor postural control in Parkinson individuals.

Physiological complexity and system adaptability: evidence from postural control dynamics of older adults.

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Manor, Brad; Costa, Madalena D; Hu, Kun; Newton, Elizabeth; Starobinets, Olga; Kang, Hyun Gu; Peng, C K; Novak, Vera; Lipsitz, Lewis A

2010-12-01

The degree of multiscale complexity in human behavioral regulation, such as that required for postural control, appears to decrease with advanced aging or disease. To help delineate causes and functional consequences of complexity loss, we examined the effects of visual and somatosensory impairment on the complexity of postural sway during quiet standing and its relationship to postural adaptation to cognitive dual tasking. Participants of the MOBILIZE Boston Study were classified into mutually exclusive groups: controls [intact vision and foot somatosensation, n = 299, 76 ± 5 (SD) yr old], visual impairment only (Postural sway (i.e., center-of-pressure) dynamics were assessed during quiet standing and cognitive dual tasking, and a complexity index was quantified using multiscale entropy analysis. Postural sway speed and area, which did not correlate with complexity, were also computed. During quiet standing, the complexity index (mean ± SD) was highest in controls (9.5 ± 1.2) and successively lower in the visual (9.1 ± 1.1), somatosensory (8.6 ± 1.6), and combined (7.8 ± 1.3) impairment groups (P = 0.001). Dual tasking resulted in increased sway speed and area but reduced complexity (P postural sway speed from quiet standing to dual-tasking conditions. Sensory impairments contributed to decreased postural sway complexity, which reflected reduced adaptive capacity of the postural control system. Relatively low baseline complexity may, therefore, indicate control systems that are more vulnerable to cognitive and other stressors.

One month of contemporary dance modulates fractal posture in aging

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Olivier A. Coubard

2014-02-01

Full Text Available Understanding the human aging of postural control and how physical or motor activity improves balance and gait is challenging for both clinicians and researchers. Previous studies have evidenced that physical and sporting activity focusing on cardiovascular and strength conditioning help older adults develop their balance and gait and/or decrease their frequency of falls. Motor activity based on motor-skill learning has also been put forward as an alternative to develop balance and/or prevent falls in aging. Specifically dance has been advocated as a promising program to boost motor control. In this study, we examined the effects of contemporary dance (CD on postural control of older adults. Upright stance posturography was performed in 38 participants aged 54-89 years before and after the intervention period, during which one half of the randomly assigned participants was trained to CD and the other half was not trained at all (no dance, ND. CD training lasted 4 weeks, 3 times a week. We performed classical statistic scores of postural signal and dynamic analyses, namely signal diffusion analysis (SDA, recurrence quantification analysis (RQA and detrended fluctuation analysis (DFA. CD modulated postural control in older trainees, as revealed in the eyes closed condition by a decrease in fractal dimension and an increase in DFA alpha component in the mediolateral plane. The ND group showed an increase in length and mean velocity of postural signal, and the eyes open a decrease in RQA maximal diagonal line in the anteroposterior plane and an increase in DFA alpha component in the mediolateral plane. No change was found in SDA in either group. We suggest that such a massed practice of CD reduced the quantity of exchanges between the subject and the environment by increasing their postural confidence. Since CD has low-physical but high-motor impact, we conclude that it may be recommended as a useful program to rehabilitate posture in aging.

Dysphagia associated with cervical spine and postural disorders.

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Papadopoulou, Soultana; Exarchakos, Georgios; Beris, Alexander; Ploumis, Avraam

2013-12-01

Difficulties with swallowing may be both persistent and life threatening for the majority of those who experience it irrespective of age, gender, and race. The purpose of this review is to define oropharyngeal dysphagia and describe its relationship to cervical spine disorders and postural disturbances due to either congenital or acquired disorders. The etiology and diagnosis of dysphagia are analyzed, focusing on cervical spine pathology associated with dysphagia as severe cervical spine disorders and postural disturbances largely have been held accountable for deglutition disorders. Scoliosis, kyphosis–lordosis, and osteophytes are the primary focus of this review in an attempt to elucidate the link between cervical spine disorders and dysphagia. It is important for physicians to be knowledgeable about what triggers oropharyngeal dysphagia in cases of cervical spine and postural disorders. Moreover, the optimum treatment for dysphagia, including the use of therapeutic maneuvers during deglutition, neck exercises, and surgical treatment, is discussed.

Evaluation of body posture in nursing students.

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Andrade, Marília Fernandes; Chaves, Érika de Cássia Lopes; Miguel, Michele Rita Oliveira; Simão, Talita Prado; Nogueira, Denismar Alves; Iunes, Denise Hollanda

2017-08-28

To investigate the body posture of nursing students before and after clinical practice. The study was developed in two stages. Initially the body posture of students of the 2nd, 4th, 6th, and 8th periods were assessed through photogrammetry. All images were analyzed in a random and masked manner with CorporisPro® 3.1.3 software. Three evaluations were performed for each angle and then the mean value was calculated. Two years later, when the 4th period students had developed their clinical internships, their body posture was again evaluated. The total sample consisted of 112 students. Comparison of their posture with the normality pattern showed that all the angles presented significant differences (pcomposta por 112 estudantes. Comparando-se os estudantes com o padrão de normalidade, todos os ângulos apresentaram diferença significativa (p< 0,00), com exceção do ângulo triângulo de Tales. Reavaliando os mesmos estudantes, houve diferença significativa nos ângulos da articulação acromioclavicular (p=0,03), da flexão de joelhos (p< 0,00) e no ângulo tibiotársico (p< 0,00). Todos os estudantes apresentaram alterações, comparadas aos valores de normalidade. Os segmentos com diferença significativa, comparando-se antes e após a prática, foram o ângulo acromioclavicular, flexo de joelho e ângulo tibiotársico, sendo os dois últimos na posição de rolamento.

Light and heavy touch reduces postural sway and modifies axial tone in Parkinson's disease.

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Franzén, Erika; Paquette, Caroline; Gurfinkel, Victor; Horak, Fay

2012-10-01

Light touch with a stable object reduces postural sway by increasing axial postural tone in healthy subjects. However, it is unknown whether subjects with Parkinson's disease (PD), who have more postural sway and higher axial postural tone than healthy subjects, can benefit from haptic touch. To investigate the effect of light and heavy touch on postural stability and hip tone in subjects with PD. Fourteen subjects with mid-stage PD and 14 healthy control subjects were evaluated during quiet standing with eyes closed with their arms (a) crossed, (b) lightly touching a fixed rigid bar in front of them, and (c) firmly gripping the bar. Postural sway was measured with a forceplate, and axial hip tone was quantified using a unique device that measures the resistance of the hips to yaw rotation while maintaining active stance. Subjects with PD significantly decreased their postural sway with light or heavy touch (P touch, hip tone was larger in PD subjects. With touch, however, tone values were similar in both groups. This change in hip tone with touch was highly correlated with the initial amount of tone (PD, r = -.72 to -.95; controls, r = -.74 to -.85). The authors showed, for the first time, that subjects with PD benefit from touch similarly to control subjects and that despite higher axial postural tone, PD subjects are able to modulate their tone with touch. Future studies should investigate the complex relationship between touch and postural tone.

Fractal based complexity measure and variation in force during sustained isometric muscle contraction: effect of aging.

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Arjunan, Sridhar P; Kumar, Dinesh K; Bastos, Teodiano

2012-01-01

This study has investigated the effect of age on the fractal based complexity measure of muscle activity and variance in the force of isometric muscle contraction. Surface electromyogram (sEMG) and force of muscle contraction were recorded from 40 healthy subjects categorized into: Group 1: Young - age range 20-30; 10 Males and 10 Females, Group 2: Old - age range 55-70; 10 Males and 10 Females during isometric exercise at Maximum Voluntary contraction (MVC). The results show that there is a reduction in the complexity of surface electromyogram (sEMG) associated with aging. The results demonstrate that there is an increase in the coefficient of variance (CoV) of the force of muscle contraction and a decrease in complexity of sEMG for the Old age group when compared with the Young age group.

Efeitos da Reeducação Postural Global em escolares com escoliose Global Posture Reeducation effects in students with scoliosis

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Pollyana Coelho Vieira Toledo

2011-12-01

Full Text Available O objetivo deste estudo foi analisar o efeito do método da Reeducação Postural Global (RPG em escolares com diagnóstico de escoliose torácica não estrutural (ETNE. Os escolares com indicativo de ETNE ao exame postural e teste de Adams negativo foram encaminhados ao exame radiográfico para comprovação diagnóstica. Foram selecionados 20 participantes (11 meninos e 9 meninas, com 10±3 anos, divididos randomicamente em dois grupos homogêneos: o que realizou o RPG (GRPG durante 12 semanas com duração de 25 a 30 minutos cada sessão, de acordo com o que aguentou permanecer na postura; e o grupo controle (GC, sem intervenção. Após três meses, os dois grupos repetiram a avaliação postural e o exame radiográfico. Para avaliação das estatísticas, foi utilizada análise de variância (ANOVA univariada, com medidas repetidas, seguida do Post Hoc de Tukey para identificar as possíveis diferenças intra e intergrupos. O valor de α foi de 0,05. O GRPG apresentou redução significativa no ângulo de Cobb na comparação intragrupo (Δ%=-35,100; p=0,009, mas o GC não (Δ%=9,520; p=0,789. Pode-se concluir que escolares submetidos ao método da RPG apresentaram melhora do quadro de escoliose torácica não estrutural.The aim of this study was to analyze the effect of Global Reeducation Postural (RPG method in scholars diagnosed with thoracic nonstructural scoliosis (ETNE. Scholars with indicative of ETNE to postural exam and Adams test negative were directed to radiographic exam to diagnostic. Twenty participants were selected (11 boys and 9 girls, 10±3 years old and randomly divided in two homogeneous groups: group treated by RPG (GRPG and control group (CG. The GRPG was submitted a RPG treatment during 12 weeks in sessions from 25 to 30 minutes in agreement with each student tolerance at posture. The CG didn't suffer intervention. After three months, both groups repeated the postural and radiographic exam. For statistics, it was used

Skeletal muscle contraction-induced vasodilation in the microcirculation.

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Hong, Kwang-Seok; Kim, Kijeong

2017-10-01

Maximal whole body exercise leads skeletal muscle blood flow to markedly increase to match metabolic demands, a phenomenon termed exercise hyperaemia that is accomplished by increasing vasodilation. However, local vasodilatory mechanisms in response to skeletal muscle contraction remain uncertain. This review highlights metabolic vasodilators released from contracting skeletal muscle, endothelium, or blood cells. As a considerable skeletal muscle vasodilation potentially results in hypotension, sympathetic nerve activity needs to be augmented to elevate cardiac output and blood pressure during dynamic exercise. However, since the enhanced sympathetic vasoconstriction restrains skeletal muscle blood flow, intramuscular arteries have an indispensable ability to blunt sympathetic activity for exercise hyperaemia. In addition, we discuss that mechanical compression of the intramuscular vasculature contributes to causing the initial phase of increasing vasodilation following a single muscle contraction. We have also chosen to focus on conducted (or ascending) electrical signals that evoke vasodilation of proximal feed arteries to elevate blood flow in the microcirculation of skeletal muscle. Endothelial hyperpolarization originating within distal arterioles ascends into the proximal feed arteries, thereby increasing total blood flow in contracting skeletal muscle. This brief review summarizes molecular mechanisms underlying the regulation of skeletal muscle blood flow to a single or sustained muscle contraction.

Postural Control and Gait Performance in the Diabetic Peripheral Neuropathy: A Systematic Review.

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Mustapa, Amirah; Justine, Maria; Mohd Mustafah, Nadia; Jamil, Nursuriati; Manaf, Haidzir

2016-01-01

Purpose. The aim of this paper is to review the published studies on the characteristics of impairments in the postural control and gait performance in diabetic peripheral neuropathy (DPN). Methods. A review was performed by obtaining publication of all papers reporting on the postural control and gait performance in DPN from Google Scholar, Ovid, SAGE, Springerlink, Science Direct (SD), EBSCO Discovery Service, and Web of Science databases. The keywords used for searching were "postural control," "balance," "gait performance," "diabetes mellitus," and "diabetic peripheral neuropathy." Results. Total of 4,337 studies were hit in the search. 1,524 studies were screened on their titles and citations. Then, 79 studies were screened on their abstract. Only 38 studies were eligible to be selected: 17 studies on postural control and 21 studies on the gait performance. Most previous researches were found to have strong evidence of postural control impairments and noticeable gait deficits in DPN. Deterioration of somatosensory, visual, and vestibular systems with the pathologic condition of diabetes on cognitive impairment causes further instability of postural and gait performance in DPN. Conclusions. Postural instability and gait imbalance in DPN may contribute to high risk of fall incidence, especially in the geriatric population. Thus, further works are crucial to highlight this fact in the hospital based and community adults.

Diurnal changes in postural control in normal children: Computerized static and dynamic assessments.

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Bourelle, Sophie; Taiar, Redha; Berge, Benoit; Gautheron, Vincent; Cottalorda, Jerome

2014-01-01

Mild traumatic brain injury (mTBI) causes postural control deficits and accordingly comparison of aberrant postural control against normal postural control may help diagnose mTBI. However, in the current literature, little is known regarding the normal pattern of postural control in young children. This study was therefore conducted as an effort to fill this knowledge gap. Eight normal school-aged children participated. Posture assessment was conducted before (7-8 a.m. in the morning) and after (4-7 p.m. in the afternoon) school on regular school days using the Balance Master® evaluation system composed of 3 static tests and 2 dynamic balance tests. A significant difference in the weight-bearing squats was detected between morning hours and afternoon hours (P control of the lateral rhythmic weight shifts was observed at the end of the afternoon than at morning hours (P posture control in humans. On a regular school day, the capacity of postural control and laterality or medio-lateral balance in children varies between morning and afternoon hours. We suggest that posturographic assessment in children, either in normal (e.g., physical education and sports training) or in abnormal conditions (e.g., mTBI-associated balance disorders), be better performed late in the afternoon.

Posture and isokinetic shoulder strength in female water polo players

African Journals Online (AJOL)

Background: Being overhead athletes, water polo players can present with muscular imbalances of the shoulder, between the internal rotators (IR) and external rotators (ER), leading to changes in posture and an increased risk of injury. Objectives: To assess posture and isokinetic shoulder strength of female club-level ...

Postural And Eye-Positional Effects On Human Biting Force: An Experimental Study

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Altay Tabancacı

2012-06-01

Full Text Available Muscle groups affected on biting force are called temporal muscle as a major and masseter muscle as a minor. According to the human posture stability, forces of these muscles vary with the force directions. In this case, experimental investigation is strictly important such that biting force under different postural and eye- positional situations is changed. In this study, seven-male and seven-female within the age-range of 17-24 are considered corresponding to having with restorated molar tooth and without that type of tooth. With the help of specially designed biting fork, different posture- and eye-positions are investigated for experimental biting force analysis. Changes in eye-positions are not indicated significant difference for all postural positions. On one hand, it is obtained that biting force of no-filling tooth in men becomes maximum if facial muscles give full effort to biting. On the other hand, effect of facial muscles for women is not clearly noticed depending on the postural differences.

Postural loading assessment in assembly workers of an Iranian telecommunication manufacturing company.

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Kamalinia, Mojtaba; Nasl Saraji, Gebreal; Kee, Dohyung; Hosseini, Mostafa; Choobineh, Alireza

2013-01-01

Changes in industries and work practices have coincided with work-related musculoskeletal disorders (MSDs). This study was conducted to determine the prevalence of MSDs and to assess postural loading in assembly workers of an Iranian telecommunication manufacturing company. Data were collected from 193 randomly selected workers in 4 units of the company. The Nordic musculoskeletal disorders questionnaire and the UBC ergonomic checklist were used as data collection tools. Loading on the upper body assessment (LUBA) was used to assess postural loading. Lower back symptoms were the most prevalent problems among the workers (67.9%). LUBA showed that most assembly workers (94.3%) had experienced considerable and high postural loading (postural load index, PLI > 5). Regression analyses revealed that lighting, rotation, contact stress, repetition, gender and age were factors associated with symptoms. Work-related MSDs occurred at a high rate among workers. Postural loading requires consideration. Any ergonomic intervention should focus on eliminating ergonomic factors associated with symptoms.

Evaluation of the lambda model for human postural control during ankle strategy.

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Micheau, Philippe; Kron, Aymeric; Bourassa, Paul

2003-09-01

An accurate modeling of human stance might be helpful in assessing postural deficit. The objective of this article is to validate a mathematical postural control model for quiet standing posture. The postural dynamics is modeled in the sagittal plane as an inverted pendulum with torque applied at the ankle joint. The torque control system is represented by the physiological lambda model. Two neurophysiological command variables of the central nervous system, designated lambda and micro, establish the dynamic threshold muscle at which motoneuron recruitment begins. Kinematic data and electromyographic signals were collected on four young males in order to measure small voluntary sway and quiet standing posture. Validation of the mathematical model was achieved through comparison of the experimental and simulated results. The mathematical model allows computation of the unmeasurable neurophysiological commands lambda and micro that control the equilibrium position and stability. Furthermore, with the model it is possible to conclude that low-amplitude body sway during quiet stance is commanded by the central nervous system.

Differences in postural disturbances between female adolescents handball players and nontraining peers

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Jandrić Slavica Đ.

2016-01-01

Full Text Available Background/Aim. Physical activity and sport can influence the extent of the presence of the postural disturbances in children. The aim of this study was to investigate the occurrence of differences in the postural disturbances in female adolescents in relation to team handball training. Methods. This investigation involved 150 female adolescents with the average age of 13.4 ± 1.5 years divided into two groups (50 adolescents trained handball and 100 did non train it. Results. The study determined a statistically significant difference in the total number of postural disturbances between the two groups of adolescents (p 0.05. Conclusion. Handball adolescents players have less postural disturbances than untrained adolescents. Flat foot is significantly less frequent in female adolescents handball players than in untrained ones. Findings obtained in this investigation can help us in planning continuous prevention, observation and care for untrained and trained team handball female adolescents with postural disturbances.

PERANCANGAN KURSI RODA DAN LAY OUT KAMAR MANDI UNTUK MEMPERBAIKI POSTUR KERJA PERAWAT PANTI WREDHA SEMARANG

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Purnawan Adi W

2012-02-01

Panti Wredha Berthany is a treatment for people who have been elderly. In this house most of the patients dapt not bathe without assistance of others. Nurses who help them a bath about the pain in the back of the spine that often dideritanya. This is due to bad postures nurse. To find out how bad postures nurses, the nurses conducted the analysis with the postures OWAS (Ovako Working Posture Analysis System. Method OWAS built as a tool to identify body postures which may be responsible for muscle problems (Musculoskeletal disorders. This method is based on the simple and systematic classification of work postures. OWAS postures in the workplace are categorized into 3 main body segment of the body, hands and feet. Kegunaanya improve conditions for workers in the work, so that work performance can be improved. Based on the results of analysis using the method OWAS, note that when the postures nurses bathe patients classified in category postures quite dangerous and very dangerous. Therefore, action needs to be improvements in form design wheelchair and lay out a bathroom can make it easier to work when the nurse wash the patient. With this design, the frequency of transfer of patients that must be done by the nurses decreased and postures during patient more better. Keywords: lay out, planning, postures in the workplace, OWAS

Comparison of postural sway depending on balance pad type.

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Lee, DongGeon; Kim, HaNa; An, HyunJi; Jang, JiEun; Hong, SoungKyun; Jung, SunHye; Lee, Kyeongbong; Choi, Myong-Ryol; Lee, Kyung-Hee; Lee, GyuChang

2018-02-01

[Purpose] The purpose of the present study was to compare the postural sway of healthy adults standing on different types of balance pads. [Subjects and Methods] Nine healthy adults participated in this study. Postural body sway was measured while participants were standing on four different types of balance pads: Balance-pad Elite (BE), Aero-Step XL (AS), Dynair Ballkissen Senso (DBS), and Dynair Ballkissen XXL Meditation and Yoga (DBMY). A Wii Balance Board interfaced with Balancia software was used to measure postural body sway. [Results] In the sway velocity, sway path length, and sway area, no significant differences were found between baseline conditions (participants were standing on the floor with no balance pad) and the use of the BE or AS. However, significant increases in all parameters were found comparing baseline conditions to the use of either Dynair balance pad. Furthermore, the use of either Dynair balance pad significantly increased postural sway compared to both the BE and the AS. [Conclusion] These findings suggest that the DBS and DBMY balance pads may serve as superior tools for providing unstable condition for balance training than the BE and the AS balance pads.

Medio-lateral postural instability in subjects with tinnitus

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Zoi eKapoula

2011-05-01

Full Text Available Background: Many patients show modulation of tinnitus by gaze, jaw or neck movements, reflecting abnormal sensorimotor integration and interaction between various inputs. Postural control is based on multi-sensory integration (visual, vestibular, somatosensory, and oculomotor and indeed there is now evidence that posture can also be influenced by sound. Perhaps tinnitus influences posture similarly to external sound. This study examines the quality of postural performance in quiet stance in patients with modulated tinnitus.Methods: Twenty-three patients with highly modulated tinnitus were selected in the ENT service. Twelve reported exclusively or predominately left tinnitus, eight right and three bilateral. Eighteen control subjects were also tested. Subjects were asked to fixate a target at 40cm for 51s; posturography was performed with the platform (Technoconcept, 40Hz for both the eyes open and eyes closed conditions.Results: For both conditions, tinnitus subjects showed abnormally high lateral body sway (SDx. This was corroborated by fast Fourrier Transformation (FFTx and wavelet analysis. For patients with left tinnitus only, medio-lateral sway increased significantly when looking away from the center. Conclusions: Similarly to external sound stimulation, tinnitus could influence lateral sway by activating attention shift, and perhaps vestibular responses. Poor integration of sensorimotor signals is another possibility. Such abnormalities would be accentuated in left tinnitus because of the importance of the right cerebral cortex in processing both auditory-tinnitus and attention.

Functional synergies underlying control of upright posture during changes in head orientation.

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Eunse Park

Full Text Available BACKGROUND: Studies of human upright posture typically have stressed the need to control ankle and hip joints to achieve postural stability. Recent studies, however, suggest that postural stability involves multi degree-of-freedom (DOF coordination, especially when performing supra-postural tasks. This study investigated kinematic synergies related to control of the body's position in space (two, four and six DOF models and changes in the head's orientation (six DOF model. METHODOLOGY/PRINCIPAL FINDINGS: Subjects either tracked a vertically moving target with a head-mounted laser pointer or fixated a stationary point during 4-min trials. Uncontrolled manifold (UCM analysis was performed across tracking cycles at each point in time to determine the structure of joint configuration variance related to postural stability or tracking consistency. The effect of simulated removal of covariance among joints on that structure was investigated to further determine the role of multijoint coordination. Results indicated that cervical joint motion was poorly coordinated with other joints to stabilize the position of the body center of mass (CM. However, cervical joints were coordinated in a flexible manner with more caudal joints to achieve consistent changes in head orientation. CONCLUSIONS/SIGNIFICANCE: An understanding of multijoint coordination requires reference to the stability/control of important performance variables. The nature of that coordination differs depending on the reference variable. Stability of upright posture primarily involved multijoint coordination of lower extremity and lower trunk joints. Consistent changes in the orientation of the head, however, required flexible coordination of those joints with motion of the cervical spine. A two-segment model of postural control was unable to account for the observed stability of the CM position during the tracking task, further supporting the need to consider multijoint coordination to

Decerebrate posturing following traumatic brain injury: MRI findings and their diagnostic value

International Nuclear Information System (INIS)

Woischneck, D.; Skalej, M.; Firsching, R.; Kapapa, T.

2015-01-01

Aim: To determine the pathomorphological and clinical background to decerebrate posturing in humans following serious traumatic brain injury. Materials and methods: One hundred and twenty patients who had been unconscious for more than 24 h underwent diagnostic MRI within 8 days after trauma. The presence of decerebrate rigidity as the clinical parameter was correlated to MRI findings, such as traumatic lesions in defined brain areas. Significance was presumed as p < 0.05. Results: On the day of MRI 43 (36%) patients exhibited decerebrate posturing: 19 (23%) cases were unilateral and 24 (77%) bilateral. There was a significant correlation between midbrain lesions and the presence of rigidity. If a midbrain lesion was found in the absence of pontine lesions, decerebrate rigidity could be concluded (p < 0.05). There was no significant correlation to the rigidity in the case of midbrain lesions accompanied by pontine lesions, and no correlation to the rigidity could be detected for other regions of the brain. Both the occurrence of decerebrate posturing and the detection of brainstem lesions at MRI correlated with the Glasgow Outcome Scale. The combination of both parameters improved the probability of predicting the outcome. Conclusion: The rate of decerebrate posturing increases significantly in the presence of midbrain lesions. The presence of pontine lesions appears to be of secondary importance. The chances of predicting the Glasgow Outcome Scale are improved by the combination of clinical information (decerebrate posturing) and radiological parameters (type of brainstem lesion). - Highlights: • The pathomorphology of decerebrate posturing after TBI is not known for certain. • Midbrain lesions on MRI were correlated significantly to decerebrate posturing. • A combination of decerebrate posturing and brainstem lesions predict poor outcome

Relationship Between Postural Control and Restricted, Repetitive Behaviors in Autism Spectrum Disorders

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Krestin eRadonovich

2013-05-01

Full Text Available Restricted, repetitive behaviors (RRBs are one of the core diagnostic criteria of autism spectrum disorders (ASD, and include simple repetitive motor behaviors and more complex cognitive behaviors, such as compulsions and restricted interests. In addition to the core symptoms, impaired movement is often observed in ASD. Research suggests that the postural system in individuals with ASD is immature and may never reach adult levels. RRBs have been related to postural sway in individuals with mental retardation.Our goals were to determine whether subjects with ASD had greater postural sway and whether RBS-R scores were related to the magnitude of postural sway. We compared the center of pressure (COP sway area during quiet stance with scores on the Repetitive Behavior Scale-Revised (RBS-R in children with ASD and typically developing controls (TD ages 3-16. All subjects had Nonverbal IQ>70. Subjects performed four quiet stance trials at a self–selected stance width for 15 seconds. Subjects with ASD had greater postural sway area compared to controls. Not surprisingly, subjects with ASD exhibited greater frequencies and intensities of RRBs overall and on all 6 subscales. Further, there was a positive correlation between postural sway area and presence of RRBs. Interestingly, results of the postural sway area for the ASD group suggests that roughly half of the ASD subjects scored comparable to TD controls, whereas the other half scored >2 SD worse. Motor impaired children did not have significantly worse IQ scores, but were younger and had more RRBs.Results support previous findings of relationships between RRBs and postural control. It appears that motor control impairments may characterize a subset of individuals with ASD. Better delineation of motor control abilities in individuals with ASD will be important to help explain variations of abilities in ASD, inform treatment, and guide examination of underlying neural involvement in this diverse

Stereotypes and prejudice affect the recognition of emotional body postures.

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Bijlstra, Gijsbert; Holland, Rob W; Dotsch, Ron; Wigboldus, Daniel H J

2018-03-26

Most research on emotion recognition focuses on facial expressions. However, people communicate emotional information through bodily cues as well. Prior research on facial expressions has demonstrated that emotion recognition is modulated by top-down processes. Here, we tested whether this top-down modulation generalizes to the recognition of emotions from body postures. We report three studies demonstrating that stereotypes and prejudice about men and women may affect how fast people classify various emotional body postures. Our results suggest that gender cues activate gender associations, which affect the recognition of emotions from body postures in a top-down fashion. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Body Context and Posture Affect Mental Imagery of Hands

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Ionta, Silvio; Perruchoud, David; Draganski, Bogdan; Blanke, Olaf

2012-01-01

Different visual stimuli have been shown to recruit different mental imagery strategies. However the role of specific visual stimuli properties related to body context and posture in mental imagery is still under debate. Aiming to dissociate the behavioural correlates of mental processing of visual stimuli characterized by different body context, in the present study we investigated whether the mental rotation of stimuli showing either hands as attached to a body (hands-on-body) or not (hands-only), would be based on different mechanisms. We further examined the effects of postural changes on the mental rotation of both stimuli. Thirty healthy volunteers verbally judged the laterality of rotated hands-only and hands-on-body stimuli presented from the dorsum- or the palm-view, while positioning their hands on their knees (front postural condition) or behind their back (back postural condition). Mental rotation of hands-only, but not of hands-on-body, was modulated by the stimulus view and orientation. Additionally, only the hands-only stimuli were mentally rotated at different speeds according to the postural conditions. This indicates that different stimulus-related mechanisms are recruited in mental rotation by changing the bodily context in which a particular body part is presented. The present data suggest that, with respect to hands-only, mental rotation of hands-on-body is less dependent on biomechanical constraints and proprioceptive input. We interpret our results as evidence for preferential processing of visual- rather than kinesthetic-based mechanisms during mental transformation of hands-on-body and hands-only, respectively. PMID:22479618

Two stages and three components of the postural preparation to action.

Science.gov (United States)

Krishnan, Vennila; Aruin, Alexander S; Latash, Mark L

2011-07-01

Previous studies of postural preparation to action/perturbation have primarily focused on anticipatory postural adjustments (APAs), the changes in muscle activation levels resulting in the production of net forces and moments of force. We hypothesized that postural preparation to action consists of two stages: (1) Early postural adjustments (EPAs), seen a few hundred ms prior to an expected external perturbation and (2) APAs seen about 100 ms prior to the perturbation. We also hypothesized that each stage consists of three components, anticipatory synergy adjustments seen as changes in covariation of the magnitudes of commands to muscle groups (M-modes), changes in averaged across trials levels of muscle activation, and mechanical effects such as shifts of the center of pressure. Nine healthy participants were subjected to external perturbations created by a swinging pendulum while standing in a semi-squatting posture. Electrical activity of twelve trunk and leg muscles and displacements of the center of pressure were recorded and analyzed. Principal component analysis was used to identify four M-modes within the space of muscle activations using indices of integrated muscle activation. This analysis was performed twice, over two phases, 400-700 ms prior to the perturbation and over 200 ms just prior to the perturbation. Similar robust results were obtained using the data from both phases. An index of a multi-M-mode synergy stabilizing the center of pressure displacement was computed using the framework of the uncontrolled manifold hypothesis. The results showed high synergy indices during quiet stance. Each of the two stages started with a drop in the synergy index followed by a change in the averaged across trials activation levels in postural muscles. There was a very long electromechanical delay during the early postural adjustments and a much shorter delay during the APAs. Overall, the results support our main hypothesis on the two stages and three components

The effect of exercise on the cardio-postural relationship

OpenAIRE

Bruner, Michelle

2012-01-01

Syncope is common in individuals who experience orthostatic hypotension which is often associated with cardiovascular conditions, brain injuries, and ageing. A bi-directional link between the cardiovascular and postural control systems was recently identified, and may provide insight into syncope and orthostatic hypotension. This thesis examined the inter-dependent relationship between cardiovascular and postural controls before and after light exercise to induce mild orthostatic stress. It w...

Detection of motion and posture change using an IR-UWB radar.

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Van Nguyen; Javaid, Abdul Q; Weitnauer, Mary A

2016-08-01

Impulse radio ultra-wide band (IR-UWB) radar has recently emerged as a promising candidate for non-contact monitoring of respiration and heart rate. Different studies have reported various radar based algorithms for estimation of these physiological parameters. The radar can be placed under a subject's mattress as he lays stationary on his back or it can be attached to the ceiling directly above the subject's bed. However, advertent or inadvertent movement on part of the subject and different postures can affect the radar returned signal and also the accuracy of the estimated parameters from it. The detection and analysis of these postural changes can not only lead to improvement in estimation algorithms but also towards prevention of bed sores and ulcers in patients who require periodic posture changes. In this paper, we present an algorithm that detects and quantifies different types of motion events using an under-the-mattress IR-UWB radar. The algorithm also indicates a change in posture after a macro-movement event. Based on the findings of this paper, we anticipate that IR-UWB radar can be used for extracting posture related information in non-clinical enviroments for patients who are bed-ridden.

Effect of awareness through movement on the head posture of bruxist children.

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Quintero, Y; Restrepo, C C; Tamayo, V; Tamayo, M; Vélez, A L; Gallego, G; Peláez-Vargas, A

2009-01-01

The aim of this study was to evaluate the effectiveness of physiotherapy to improve the head posture and reduce the signs of bruxism in a group of bruxist children. A single-blind randomized clinical trial was performed. All the subjects were 3- to 6-year old, had complete primary dentition, dental and skeletal class I occlusion and were classified as bruxist according to the minimal criteria of the ICSD for bruxism. For each child, a clinical, photographic and radiographic evaluation of the head and cervical posture were realized with standardized techniques. The children were randomized in an experimental (n = 13) and a control (n = 13) group. A physiotherapeutic intervention was applied to the children of the experimental group once a week, until 10 sessions were completed. Afterwards, the cephalogram and the clinical and photographic evaluation of the head posture were measured again. The data were analysed with the t-test and Mann-Whitney test. The subjects of the experimental group showed statistically significant improvement in the natural head posture. The physiotherapeutic intervention showed to be efficient to improve the head posture at the moment of measurement in the studied children. The relationship between bruxism and head posture, if exists, seems to be worthwhile to examine.

Auditory white noise reduces postural fluctuations even in the absence of vision.

Science.gov (United States)

Ross, Jessica Marie; Balasubramaniam, Ramesh

2015-08-01