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Sample records for interlimb postural coordination

  1. The role of anticipatory postural adjustments in interlimb coordination of coupled arm movements in the parasagittal plane: III. difference in the energy cost of postural actions during cyclic flexion-extension arm movements, ISO- and ANTI-directionally coupled.

    Science.gov (United States)

    Esposti, Roberto; Limonta, Eloisa; Esposito, Fabio; Baldissera, Fausto G

    2013-11-01

    When oscillating the upper limbs together in the parasagittal plane, movements coordination is lower (i.e., variability of the interlimb relative phase is higher) in antidirectional (ANTI) than in isodirectional (ISO) coupling. In contrast, we previously observed that for arm movements in the horizontal plane, the coordination was worse in ISO than ANTI and the energetic cost of postural activities was higher in ISO. Having hypothesised that the higher postural cost was one factor responsible for the coordination deficit in horizontal ISO, we measured the oxygen uptake ([Formula: see text]) in parasagittal movements, expecting that in this case too, the postural cost is higher in the less-coordinated mode (ANTI). Breath-by-breath metabolic ([Formula: see text], [Formula: see text]) and cardiorespiratory (HR, [Formula: see text]) parameters were measured in seven participants, who performed cyclic flexions-extensions in the parasagittal plane with either one arm or both arms, in ISO or ANTI coupling and at 1.4, 2.2 and 2.6 Hz. In each condition, the intermittent exercise (12 s movement, 12 s rest) lasted 264 s. A force platform recorded the mechanical actions to the ground. The exercise metabolic cost ([Formula: see text]) was found to be significantly higher in parasagittal ANTI than ISO. The movement amplitude being equal in the two modes, the ANTI-ISO difference should be ascribed to postural activities. This would confirm that the less-coordinated coupling mode requires the higher postural effort in parasagittal movements too. When rising the movement frequency, [Formula: see text] increased and linearly correlated with the coordination loss. Comparison of parasagittal with horizontal movements showed that [Formula: see text] was lower in parasagittal ANTI than in horizontal ISO (the less-coordinated modes), while it was not different between parasagittal ISO and horizontal ANTI (the more-coordinated modes).

  2. Interlimb Coordination: An Important Facet of Gross-Motor Ability

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    Bobbio, Tatiana; Gabbard, Carl; Cacola, Priscila

    2009-01-01

    Motor development attains landmark significance during early childhood. Although early childhood educators may be familiar with the gross-motor skill category, the subcategory of interlimb coordination needs greater attention than it typically receives from teachers of young children. Interlimb coordination primarily involves movements requiring…

  3. The role of anticipatory postural adjustments in interlimb coordination of coupled arm movements in the parasagittal plane: II. Postural activities and coupling coordination during cyclic flexion-extension arm movements, ISO- and ANTI-directionally coupled.

    Science.gov (United States)

    Baldissera, Fausto G; Esposti, Roberto

    2013-08-01

    When coupling cyclic adduction-abduction movements of the arms in the transverse (horizontal) plane, isodirectional (ISO) coupling is less stable than antidirectional (ANTI) coupling. We proposed that such deficiency stems from the disturbing action that anticipatory postural adjustments exert on ISO coupling. To ascertain if postural adjustments differentiate ISO versus ANTI coupling coordination in other types of cyclic arm movements, we examined flexion-extension oscillations in the parasagittal plane. Oscillations of the right arm alone elicited cyclic Postural Adjustments (PAs) in the left Anterior Deltoid and Posterior Deltoid, which replicated the excitation-inhibition pattern of the prime movers right Anterior Deltoid, right Posterior Deltoid. Cyclic PAs also developed symmetrically in Erector Spinae (RES and LES) and in phase opposition in Ischiocruralis (RIC and LIC), so as to discharge to the ground both an anteroposterior force, Fy, and a moment about the vertical axis, Tz. Oscillations of both arms in ISO coupling induced symmetric PAs in both ES and IC muscles, thus generating a large Fy but no Tz. In ANTI coupling, PAs in RES and LES remained symmetric but smaller in size, while PAs in RIC and LIC were large and opposite in phase, resulting in a large Tz and small Fy. Altogether, PAs would thus favour ISO and hamper ANTI parasagittal movements because (1) in the motor pathways to the prime movers of either arm, a convergence would occur between the voluntary commands and the commands for PAs linked to the movement of the other arm, the two commands having the same sign (excitatory or inhibitory) during ISO and an opposite sign during ANTI; (2) the postural effort of trunk and leg muscles would be higher for generating Tz in ANTI than Fy in ISO. These predictions fit with the finding that coupling stability was lower in ANTI than in ISO, i.e., opposite to horizontal movements. In conclusion, in both parasagittal and horizontal arm movements, the less

  4. HUMAN NEURONAL INTERLIMB COORDINATION DURING SPLIT-BELT LOCOMOTION

    NARCIS (Netherlands)

    DIETZ, [No Value; ZIJLSTRA, W; DUYSENS, J

    1994-01-01

    Human interlimb coordination and the adaptations in leg muscle activity were studied during walking on a treadmill with split belts. Four different belt speeds (0.5, 1.0, 1.5, 2.0 m/s) were offered in all possible combinations for the left and right leg. Subjects adapted automatically to a differenc

  5. Human neuronal interlimb coordination during split-belt locomotion

    NARCIS (Netherlands)

    Dietz, V.; Zijlstra, W.G.; Duysens, J.E.J.

    1994-01-01

    Human interlimb coordination and the adaptations in leg muscle activity were studied during walking on a treadmill with split belts. Four different belt speeds (0.5, 1.0, 1.5, 2.0 m/s) were offered in all possible combinations for the left and right leg. Subjects adapted automatically to a differenc

  6. Interlimb coordination and academic performance in elementary school children.

    Science.gov (United States)

    da Silva Pacheco, Sheila Cristina; Gabbard, Carl; Ries, Lilian Gerdi Kittel; Bobbio, Tatiana Godoy

    2016-10-01

    The specific mechanisms linking motor ability and cognitive performance, especially academic achievement, are still unclear. Whereas the literature provides an abundance of information on fine and visual-motor skill and cognitive attributes, much less has been reported on gross motor ability. This study examined interlimb coordination and its relationship to academic performance in children aged 8-11 years. Motor and academic skills were examined in 100 Brazilian children using the Bruininks-Oseretsky Test of Motor Proficiency and the Academic Performance Test. Participants were grouped into low (75%) academic achievers. There was a significant difference between groups for Total Motor Composite (P Coordination. Of the subtests of Body Coordination (Bilateral Coordination and Balance), Bilateral Coordination accounted for the highest impact on academic performance. Of interest here, that subtest consists primarily of gross motor tasks involving interlimb coordination. Overall, there was a positive relationship between motor behavior, in particular activities involving interlimb coordination, and academic performance. Application of these findings in the area of early assessment may be useful in the identification of later academic problems. © 2016 Japan Pediatric Society.

  7. Impaired Interlimb Coordination of Voluntary Leg Movements in Poststroke Hemiparesis

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    Tseng, Shih-Chiao

    2010-01-01

    Appropriate interlimb coordination of the lower extremities is particularly important for a variety of functional human motor behaviors such as jumping, kicking a ball, or simply walking. Specific interlimb coordination patterns may be especially impaired after a lesion to the motor system such as stroke, yet this has not been thoroughly examined to date. The purpose of this study was to investigate the motor deficits in individuals with chronic stroke and hemiparesis when performing unilateral versus bilateral inphase versus bilateral antiphase voluntary cyclic ankle movements. We recorded ankle angular trajectories and muscle activity from the dorsiflexors and plantarflexors and compared these between subjects with stroke and a group of healthy age-matched control subjects. Results showed clear abnormalities in both the kinematics and EMG of the stroke subjects, with significant movement degradation during the antiphase task compared with either the unilateral or the inphase task. The abnormalities included prolonged cycle durations, reduced ankle excursions, decreased agonist EMG bursts, and reduced EMG modulation across movement phases. By comparison, the control group showed nearly identical performance across all task conditions. These findings suggest that stroke involving the corticospinal system projection to the leg specifically impairs one or more components of the neural circuitry involved in lower extremity interlimb coordination. The express susceptibility of the antiphase pattern to exaggerated motor deficits could contribute to functional deficits in a number of antiphase leg movement tasks, including walking. PMID:20463199

  8. Human neuronal interlimb coordination during split-belt locomotion

    OpenAIRE

    Dietz, V; Zijlstra, W G; Duysens, J.E.J.

    1994-01-01

    Human interlimb coordination and the adaptations in leg muscle activity were studied during walking on a treadmill with split belts. Four different belt speeds (0.5, 1.0, 1.5, 2.0 m/s) were offered in all possible combinations for the left and right leg. Subjects adapted automatically to a difference in belt speed within 10–20 stride cycles.This adaptation was achieved by a reorganization of the stride cycle with a relative shortening of the duration of the support and lengthening of the swin...

  9. Social Postural Coordination

    Science.gov (United States)

    Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.

    2011-01-01

    The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…

  10. Social Postural Coordination

    Science.gov (United States)

    Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.

    2011-01-01

    The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…

  11. Laterally focused attention modulates asymmetric coupling in rhythmic interlimb coordination.

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    de Poel, Harjo J; Peper, C Lieke E; Beek, Peter J

    2008-03-01

    Peters (J Motor Behav 21:151-155, 1989; Interlimb coordination: neural, dynamical and cognitive constraints, Academic, Orlando, pp 595-615, 1994) suggested that expressions of handedness in bimanual coordination may be reflections of an inherent attentional bias. Indeed, previous results indicated that focusing attention on one of the limbs affected the relative phasing between the limbs in a manner comparable to the effects of hand dominance. The present study extended the comparison between the effects of attentional focus and handedness by testing their impact on the interactions between the limbs. Both left-handed and right-handed participants performed rhythmic bimanual coordination tasks (in-phase and antiphase coordination), while directing attention to either limb. Using brief mechanical perturbations, the degree to which the limbs were influenced by each other was determined. The results revealed that the non-dominant limb was more strongly affected by the dominant limb than vice versa and that, in line with Peters' proposition, this handedness-related asymmetry in coupling strength was reduced when attention was focused on the non-dominant limb, thereby highlighting the potential relation between inherent (handedness-related) asymmetries and voluntary attentional asymmetries. In contrast to previous findings, the (commonly observed) phase lead of the dominant limb was attenuated (rather than accrued) when attention was focused on this limb. This unexpected result was explained in terms of the observed attention-related difference in amplitude between the limbs.

  12. Interlimb communication

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas

    A continual coordination between the two legs is necessary for maintaining a symmetric walking pattern and adapting to changes in the external environment. Recent evidence in animals and humans suggests that spinal interneuronal circuits under supraspinal control may mediate communication between...... the lower limbs. The overall objective of the present thesis was to further investigate and elucidate neural pathways underlying interlimb communication in humans, focusing primarily on the possible interlimb connections to the biceps femoris muscle. The major aims were 1) to investigate whether interlimb...... walking (Study IV). The results of the this thesis provide new insights into the neural mechanisms underlying human interlimb communication, as well as their functional relevance to human locomotion. Although it is difficult to propose the exact neural pathways mediating interlimb reflexes...

  13. Learning a new bimanual coordination pattern: interlimb interactions, attentional focus, and transfer.

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    de Boer, Betteco J; Peper, C Lieke E; Beek, Peter J

    2013-01-01

    Because bimanual coordinative stability is governed by interlimb coupling, we examined how learning a new pattern (90°) was reflected in changes in the underlying interlimb interactions. Three interlimb interaction sources were distinguished: integrated timing of feedforward control signals, error corrections based on perceived relative phase, and phase entrainment by contralateral afference. By comparing 4 tasks that involve these interactions to a different extent, changes in the stabilizing contributions of these coupling sources could be studied. Furthermore, we studied how the learning process and changes in the underlying interactions were influenced by attentional focus (internal vs. external), and we examined retention of the learned pattern and transfer to the mirror-symmetrical pattern (270°). Results showed that stability and accuracy of the new pattern increased significantly with learning, due to improved integrated timing and error correction. Integrated timing improved first, possibly providing a reference frame for the error corrections that subsequently became more effective. Despite some qualitative differences in the learning process, neither performance of the learned pattern nor the underlying interlimb interactions was influenced by attentional focus. Whereas the learned pattern improved directly after practice, transfer followed later, suggesting that a more general representation was formed at a slower rate after practice.

  14. Emergence and stability of interlimb coordination patterns in children with developmental coordination disorder.

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    de Castro Ferracioli, Marcela; Hiraga, Cynthia Yukiko; Pellegrini, Ana Maria

    2014-02-01

    The purpose of this study was to investigate the emergence and stability of coordination patterns in children with developmental coordination disorder (DCD) when performing a rhythmic interlimb coordination task on rigid (floor) and elastic (mini-trampoline) surfaces. Twelve typically developing (TD) children and 12 children with DCD were required to clap while jumping under different conditions: in a chosen pattern - Free; when the feet touched the surface - Clapping-surface; when the body reached the maximum jumping height - Clapping-jump; and when the feet touched the surface and the body reached the maximum jumping height - Clapping-both. The results showed that the coordination pattern of children with DCD was more variable in the Free, Clapping-surface, and Clapping-jumping conditions and more variable on the mini-trampoline than on the floor under the Free condition when compared with the TD children. Clapping-jumping was more difficult to perform than Clapping-surface for both groups. These findings suggest that the children with DCD were less capable of rhythmically coordinating the jumping-clapping task because they used a type of exploratory strategy regarding the physical properties of the surfaces, whereas the TD children used a type of adaptive strategy displaying behavior that was more consistent across the tasks/environmental demands.

  15. Attentional Loads Associated with Interlimb Interactions Underlying Rhythmic Bimanual Coordination

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    Ridderikhoff, Arne; Peper, C. E.; Beek, Peter J.

    2008-01-01

    Studies of rhythmic bimanual coordination under dual-task conditions revealed (1) a dependence of secondary task performance on the stability of coordinative tasks, in that secondary task performance was better during in-phase than antiphase coordination, and (2) a shift in the mean relative phasing between the limbs compared to single-task…

  16. Rhythmic Interlimb Coordination Impairments and the Risk for Developing Mobility Limitations.

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    James, Eric G; Leveille, Suzanne G; Hausdorff, Jeffrey M; Travison, Thomas; Kennedy, David N; Tucker, Katherine L; Al Snih, Soham; Markides, Kyriakos S; Bean, Jonathan F

    2017-08-01

    The identification of novel rehabilitative impairments that are risk factors for mobility limitations may improve their prevention and treatment among older adults. We tested the hypothesis that impaired rhythmic interlimb ankle and shoulder coordination are risk factors for subsequent mobility limitations among older adults. We conducted a 1-year prospective cohort study of community-dwelling older adults (N = 99) aged 67 years and older who did not have mobility limitations (Short Physical Performance Battery score > 9) at baseline. Participants performed antiphase coordination of the right and left ankles or shoulders while paced by an auditory metronome. Using multivariable logistic regression, we determined odds ratios (ORs) for mobility limitations at 1-year follow-up as a function of coordination variability and asymmetry. After adjusting for age, sex, body mass index, Mini-Mental State Examination score, number of chronic conditions, and baseline Short Physical Performance Battery score, ORs were significant for developing mobility limitations based on a 1 SD difference in the variability of ankle (OR = 1.88; 95% confidence interval [CI]: 1.16-3.05) and shoulder (OR = 1.96; 95% CI: 1.17-3.29) coordination. ORs were significant for asymmetry of shoulder (OR = 2.11; 95% CI: 1.25-3.57), but not ankle (OR = 0.95; 95% CI: 0.59-1.55) coordination. Similar results were found in unadjusted analyses. The results support our hypothesis that impaired interlimb ankle and shoulder coordination are risk factors for the development of mobility limitations. Future work is needed to further examine the peripheral and central mechanisms underlying this relationship and to test whether enhancing coordination alters mobility limitations.

  17. Neuromuscular stimulation therapy after incomplete spinal cord injury promotes recovery of interlimb coordination during locomotion

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    Jung, R.; Belanger, A.; Kanchiku, T.; Fairchild, M.; Abbas, J. J.

    2009-10-01

    The mechanisms underlying the effects of neuromuscular electrical stimulation (NMES) induced repetitive limb movement therapy after incomplete spinal cord injury (iSCI) are unknown. This study establishes the capability of using therapeutic NMES in rodents with iSCI and evaluates its ability to promote recovery of interlimb control during locomotion. Ten adult female Long Evans rats received thoracic spinal contusion injuries (T9; 156 ± 9.52 Kdyne). 7 days post-recovery, 6/10 animals received NMES therapy for 15 min/day for 5 days, via electrodes implanted bilaterally into hip flexors and extensors. Six intact animals served as controls. Motor function was evaluated using the BBB locomotor scale for the first 6 days and on 14th day post-injury. 3D kinematic analysis of treadmill walking was performed on day 14 post-injury. Rodents receiving NMES therapy exhibited improved interlimb coordination in control of the hip joint, which was the specific NMES target. Symmetry indices improved significantly in the therapy group. Additionally, injured rodents receiving therapy more consistently displayed a high percentage of 1:1 coordinated steps, and more consistently achieved proper hindlimb touchdown timing. These results suggest that NMES techniques could provide an effective therapeutic tool for neuromotor treatment following iSCI.

  18. Interlimb coordination during forward and backward walking in primary school-aged children.

    Directory of Open Access Journals (Sweden)

    Pieter Meyns

    Full Text Available Previous studies comparing forward (FW and backward (BW walking suggested that the leg kinematics in BW were essentially those of FW in reverse. This led to the proposition that in adults the neural control of FW and BW originates from the same basic neural circuitry. One aspect that has not received much attention is to what extent development plays a role in the maturation of neural control of gait in different directions. BW has been examined either in adults or infants younger than one year. Therefore, we questioned which changes occur in the intermediate phases (i.e. in primary school-aged children. Furthermore, previous research focused on the lower limbs, thereby raising the question whether upper limb kinematics are also simply reversed from FW to BW. Therefore, in the current study the emphasis was put both on upper and lower limb movements, and the coordination between the limbs. Total body 3D gait analysis was performed in primary school-aged children (N = 24, aged five to twelve years at a preferred walking speed to record angular displacements of upper arm, lower arm, upper leg, lower leg, and foot with respect to the vertical (i.e. elevation angle. Kinematics and interlimb coordination were compared between FW and BW. Additionally, elevation angle traces of BW were reversed in time (revBW and correlated to FW traces. Results showed that upper and lower limb kinematics of FW correlated highly to revBW kinematics in children, which appears to be consistent with the proposal that control of FW and BW may be similar. In addition, age was found to mildly alter lower limb kinematic patterns. In contrast, interlimb coordination was similar across all children, but was different compared to adults, measured for comparison. It is concluded that development plays a role in the fine-tuning of neural control of FW and BW.

  19. Rhythmic Interlimb Coordination Impairments Are Associated With Mobility Limitations Among Older Adults.

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    James, Eric G; Leveille, Suzanne G; Hausdorff, Jeffrey M; Travison, Thomas; Cote, Sarah; Conatser, Philip; Karabulut, Murat; Mendes, Andrea C; Kennedy, David N; Tucker, Katherine L; Al Snih, Soham; Markides, Kyriakos S; Bean, Jonathan F

    2017-01-01

    Background/Study Context: Mobility limitations affect more than 25% of adults aged 70 years or older. This study tested the hypothesis that impairments in ankle and shoulder coordination are associated with mobility limitations among older adults. his study consisted of conducted a cross-sectional analysis from a sample of community-dwelling older adults (N = 130) aged ≥67 years. Motion capture equipment was used to collect kinematic data during rhythmic antiphase coordination of the right and left: (a) ankles moving in dorsi-plantarflexion; and (b) glenohumeral ("shoulder") moving in flexion-extension while paced by an auditory metronome. Coordination variability was measured as the standard deviation of the relative phase between right and left body segments. Mobility limitations were defined as a score of ≤9 on the Short Physical Performance Battery (SPPB). Odds ratios for mobility limitations as a function of coordination variability quartiles were determined using multivariable logistic regression. Adjusting for age, gender, body mass index, number of chronic conditions and Mini-Mental State Examination score, the odds ratios for mobility limitation (SPPB score ≤9) were 7.38 (95% confidence interval [CI]: 2.20-24.78) and 15.40 (95% CI: 4.31-55.07) for the 3rd and 4th (the poorest) ankle coordination quartiles, respectively, and 6.73 (95% CI: 2.11-21.51) for the 4th shoulder coordination quartile, compared with the best (the 1st) coordination quartiles. The results supported the hypothesis that impaired interlimb ankle and shoulder coordination are associated with the manifestation of mobility limitations. These findings indicate the need for further study of the role of coordination impairments as potential contributors to poor mobility among older adults.

  20. Central generation of grooming motor patterns and interlimb coordination in locusts.

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    Berkowitz, A; Laurent, G

    1996-12-15

    Coordinated bursts of leg motoneuron activity were evoked in locusts with deefferented legs by tactile stimulation of sites that evoke grooming behavior. This suggests that insect thoracic ganglia contain central pattern generators for directed leg movements. Motoneuron recordings were made from metathoracic and mesothoracic nerves, after eliminating all leg motor innervation, as well as all input from the brain, subesophageal ganglion, and prothoracic ganglion. Strong, brief trochanteral levator motoneuron bursts occurred, together with silence of the slow and fast trochanteral depressor motoneurons and activation of the common inhibitor motoneuron. The metathoracic slow tibial extensor motoneuron was active in a pattern distinct from its activity during walking or during rhythms evoked by the muscarinic agonist pilocarpine. Preparations in which the metathoracic ganglion was isolated from all other ganglia could still produce fictive motor patterns in response to tactile stimulation of metathoracic locations. Bursts of trochanteral levator and depressor motoneurons were clearly coordinated between the left and right metathoracic hemiganglia and also between the mesothoracic and the ipsilateral metathoracic ganglia. These data provide clear evidence for centrally generated interlimb coordination in an insect.

  1. Interlimb Coordination during Tied-Belt and Transverse Split-Belt Locomotion before and after an Incomplete Spinal Cord Injury.

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    Thibaudier, Yann; Hurteau, Marie-France; Dambreville, Charline; Chraibi, Anass; Goetz, Laurent; Frigon, Alain

    2017-05-01

    Coordination between the arms/forelimbs and legs/hindlimbs is often impaired in humans and quadrupedal mammals after incomplete spinal cord injury. In quadrupeds, the forelimbs often take more steps than the hindlimbs, producing a two-to-one forelimb-hindlimb (2-1 FL-HL) coordination. In locomotor performance scales, this is generally considered a loss of FL-HL coordination. Here, FL-HL coordination was quantified before and 8 weeks after a lateral spinal hemisection at the sixth thoracic segment in six adult cats. Cats were tested during tied-belt locomotion (equal front and rear speeds) and transverse split-belt locomotion with the forelimbs or hindlimbs stepping faster. The results show that consistent phasing between forelimb and hindlimb movements was maintained after hemisection, even with the appearance of 2-1 FL-HL coordination, indicating that new stable forms of coordination emerge. Moreover, transverse split-belt locomotion potently modulated interlimb coordination and was capable of restoring a one-to-one FL-HL coordination with a faster treadmill speed for the hindlimbs. In conclusion, the results suggest that neural communication persists after an incomplete spinal cord injury, despite an unequal number of steps between the forelimbs and hindlimbs, and that interlimb coordination can be modulated by having the forelimbs or hindlimbs move at a faster frequency. We propose that locomotor recovery scales incorporate more sensitive methods to quantify FL-HL coordination, to better reflect residual functional capacity and possible cervicolumbar neural communication. Lastly, devising training protocols that make use of the bidirectional influences of the cervical and lumbar locomotor pattern generators could strengthen interlimb coordination and promote locomotor recovery.

  2. Interlimb coordination in human crawling reveals similarities in development and neural control with quadrupeds.

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    Patrick, Susan K; Noah, J Adam; Yang, Jaynie F

    2009-02-01

    The study of quadrupeds has furnished most of our understanding of mammalian locomotion. To allow a more direct comparison of coordination between the four limbs in humans and quadrupeds, we studied crawling in the human, a behavior that is part of normal human development and mechanically more similar to quadrupedal locomotion than is bipedal walking. Interlimb coordination during hands-and-knees crawling is compared between humans and quadrupeds and between human infants and adults. Mechanical factors were manipulated during crawling to understand the relative contributions of mechanics and neural control. Twenty-six infants and seven adults were studied. Video, force plate, and electrogoniometer data were collected. Belt speed of the treadmill, width of base, and limb length were manipulated in adults. Influences of unweighting and limb length were explored in infants. Infants tended to move diagonal limbs together (trot-like). Adults additionally moved ipsilateral limbs together (pace-like). At lower speeds, movements of the four limbs were more equally spaced in time, with no clear pairing of limbs. At higher speeds, running symmetrical gaits were never observed, although one adult galloped. Widening stance prevented adults from using the pace-like gait, whereas lengthening the hind limbs (hands-and-feet crawling) largely prevented the trot-like gait. Limb length and unweighting had no effect on coordination in infants. We conclude that human crawling shares features both with other primates and with nonprimate quadrupeds, suggesting similar underlying mechanisms. The greater restriction in coordination patterns used by infants suggests their nervous system has less flexibility.

  3. Interlimb coordination in body-weight supported locomotion: A pilot study.

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    Seiterle, Stefan; Susko, Tyler; Artemiadis, Panagiotis K; Riener, Robert; Igo Krebs, Hermano

    2015-08-20

    Locomotion involves complex neural networks responsible for automatic and volitional actions. During locomotion, motor strategies can rapidly compensate for any obstruction or perturbation that could interfere with forward progression. In this pilot study, we examined the contribution of interlimb pathways for evoking muscle activation patterns in the contralateral limb when a unilateral perturbation was applied and in the case where body weight was externally supported. In particular, the latency of neuromuscular responses was measured, while the stimulus to afferent feedback was limited. The pilot experiment was conducted with six healthy young subjects. It employed the MIT-Skywalker (beta-prototype), a novel device intended for gait therapy. Subjects were asked to walk on the split-belt treadmill, while a fast unilateral perturbation was applied mid-stance by unexpectedly lowering one side of the split-treadmill walking surfaces. Subject's weight was externally supported via the body-weight support system consisting of an underneath bicycle seat and the torso was stabilized via a loosely fitted chest harness. Both the weight support and the chest harness limited the afferent feedback. The unilateral perturbations evoked changes in the electromyographic activity of the non-perturbed contralateral leg. The latency of all muscle responses exceeded 100ms, which precludes the conjecture that spinal cord alone is responsible for the perturbation response. It suggests the role of supraspinal or midbrain level pathways at the inter-leg coordination during gait.

  4. 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.

  5. Postural Coordination during Socio-motor Improvisation.

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    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.

  6. Investigation on Inter-Limb Coordination and Motion Stability, Intensity and Complexity of Trunk and Limbs during Hands-Knees Crawling in Human Adults.

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    Ma, Shenglan; Chen, Xiang; Cao, Shuai; Yu, Yi; Zhang, Xu

    2017-03-28

    This study aimed to investigate the inter-limb coordination pattern and the stability, intensity, and complexity of the trunk and limbs motions in human crawling under different speeds. Thirty healthy human adults finished hands-knees crawling trials on a treadmill at six different speeds (from 1 km/h to 2.5 km/h). A home-made multi-channel acquisition system consisting of five 3-axis accelerometers (ACC) and four force sensors was used for the data collection. Ipsilateral phase lag was used to represent inter-limb coordination pattern during crawling and power, harmonic ratio, and sample entropy of acceleration signals were adopted to depict the motion intensity, stability, and complexity of trunk and limbs respectively. Our results revealed some relationships between inter-limb coordination patterns and the stability and complexity of trunk movement. Trot-like crawling pattern was found to be the most stable and regular one at low speed in the view of trunk movement, and no-limb-pairing pattern showed the lowest stability and the greatest complexity at high speed. These relationships could be used to explain why subjects tended to avoid no-limb-pairing pattern when speed was over 2 km/h no matter which coordination type they used at low speeds. This also provided the evidence that the central nervous system (CNS) chose a stable inter-limb coordination pattern to keep the body safe and avoid tumbling. Although considerable progress has been made in the study of four-limb locomotion, much less is known about the reasons for the variety of inter-limb coordination. The research results of the exploration on the inter-limb coordination pattern choice during crawling from the standpoint of the motion stability, intensity, and complexity of trunk and limbs sheds light on the underlying motor control strategy of the human CNS and has important significance in the fields of clinical diagnosis, rehabilitation engineering, and kinematics research.

  7. Development of the Coordination between Posture and Manual Control

    Science.gov (United States)

    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…

  8. Sensory Feedback in Interlimb Coordination: Contralateral Afferent Contribution to the Short-Latency Crossed Response during Human Walking

    Science.gov (United States)

    Gervasio, Sabata; Voigt, Michael; Kersting, Uwe G.; Farina, Dario; Sinkjær, Thomas

    2017-01-01

    A constant coordination between the left and right leg is required to maintain stability during human locomotion, especially in a variable environment. The neural mechanisms underlying this interlimb coordination are not yet known. In animals, interneurons located within the spinal cord allow direct communication between the two sides without the need for the involvement of higher centers. These may also exist in humans since sensory feedback elicited by tibial nerve stimulation on one side (ipsilateral) can affect the muscles activation in the opposite side (contralateral), provoking short-latency crossed responses (SLCRs). The current study investigated whether contralateral afferent feedback contributes to the mechanism controlling the SLCR in human gastrocnemius muscle. Surface electromyogram, kinematic and kinetic data were recorded from subjects during normal walking and hybrid walking (with the legs moving in opposite directions). An inverse dynamics model was applied to estimate the gastrocnemius muscle proprioceptors’ firing rate. During normal walking, a significant correlation was observed between the magnitude of SLCRs and the estimated muscle spindle secondary afferent activity (P = 0.04). Moreover, estimated spindle secondary afferent and Golgi tendon organ activity were significantly different (P ≤ 0.01) when opposite responses have been observed, that is during normal (facilitation) and hybrid walking (inhibition) conditions. Contralateral sensory feedback, specifically spindle secondary afferents, likely plays a significant role in generating the SLCR. This observation has important implications for our understanding of what future research should be focusing on to optimize locomotor recovery in patient populations. PMID:28060839

  9. The role of anticipatory postural adjustments (APAs) in interlimb coordination of coupled arm movements in the parasagittal plane: I. APAs associated with fast discrete flexion and extension movements of one arm or of both arms ISO- and ANTI-directionally coupled.

    Science.gov (United States)

    Esposti, Roberto; Baldissera, Fausto G

    2013-08-01

    Coupling stability during cyclic arm movements in the horizontal (transverse) plane is lower in ISO- than in ANTI-directional coupling. We proposed that such impairment arises from the interference exerted in ISO by the anticipatory postural adjustments (APAs) linked to the primary movements. To evaluate if a link between coupling stability and postural adjustments also exist for arm movements with different postural requirements, we focused on arm(s) flexion-extension in the parasagittal plane and started by analysing the APAs distribution in arm, trunk and leg muscles. Fast flexion and extension of the right arm elicited APAs in the left anterior and posterior deltoid that replicated the excitation-inhibition of the homologous prime movers; this pattern would favour ISO and contrast ANTI-coupled movements. Instead, in the left latissimus dorsi, APAs were opposite to the voluntary actions in the right latissimus dorsi, thus favouring ANTI coupling. Symmetrical APAs were also elicited in right and left erector spinae (RES, LES) and asymmetrical APAs in Ischiocruralis (RIC, LIC), while an antero-posterior force (Fy) and a moment about the vertical axis (Tz) were discharged to the ground. When fast discrete movements were ISO-coupled, APAs were symmetrical in trunk (RES, LES) and leg (RIC, LIC) muscles and a large Fy but no Tz was generated. In ANTI coupling, APAs in RES and LES remained symmetrical, whereas they became antisymmetrical in RIC and LIC. A large Tz and a small Fy were recorded. In conclusion, during parasagittal movements, APAs in are elicited in both ISO and ANTI coupling, at variance with horizontal movements where they are only present in ISO. This would suggest that the difference in coupling stability between the two modes is smaller (or even reversed) in parasagittal with respect to horizontal arm movements.

  10. Development of the Coordination between Posture and Manual Control

    OpenAIRE

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

    2011-01-01

    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 7- and 10- year-old children, and adults during a precision fitting task as task constraints became more difficult. Participants fit a block through an opening as arm kinematics, trunk kinematics a...

  11. Leg muscle activation during gait in Parkinson's disease : Adaptation and interlimb coordination

    NARCIS (Netherlands)

    Dietz, [No Value; Zijlstra, W; Prokop, T; Berger, W

    1995-01-01

    Adaptation in leg muscle activity and coordination between lower limbs were studied during walking on a treadmill with split belts in one group of parkinsonian patients and one of age-matched healthy subjects. Four different belt speeds (0.25/0.5/0.75/1.0 m/sec) were applied in selected combinations

  12. Split-arm swinging: the effect of arm swinging manipulation on interlimb coordination during walking.

    Science.gov (United States)

    Bondi, Moshe; Zeilig, Gabi; Bloch, Ayala; Fasano, Alfonso; Plotnik, Meir

    2017-08-01

    Human locomotion is defined by bilateral coordination of gait (BCG) and shared features with the fore-hindlimb coordination of quadrupeds. The objective of the present study is to explore the influence of arm swinging (AS) on BCG. Sixteen young, healthy individuals (eight women; eight right motor-dominant, eight left-motor dominant) participated. Participants performed 10 walking trials (2 min). In each of the trials AS was unilaterally manipulated (e.g., arm restriction, weight on the wrist), bilaterally manipulated, or not manipulated. The order of trials was random. Walking trials were performed on a treadmill. Gait kinematics were recorded by a motion capture system. Using feedback-controlled belt speed allowed the participants to walk at a self-determined gait speed. Effects of the manipulations were assessed by AS amplitudes and the phase coordination index (PCI), which quantifies the left-right anti-phased stepping pattern. Most of the AS manipulations caused an increase in PCI values (i.e., reduced lower limb coordination). Unilateral AS manipulation had a reciprocal effect on the AS amplitude of the other arm such that, for example, over-swinging of the right arm led to a decrease in the AS amplitude of the left arm. Side of motor dominance was not found to have a significant impact on PCI and AS amplitude. The present findings suggest that lower limb BCG is markedly influenced by the rhythmic AS during walking. It may thus be important for gait rehabilitation programs targeting BCG to take AS into account.NEW & NOTEWORTHY Control mechanisms for four-limb coordination in human locomotion are not fully known. To study the influence of arm swinging (AS) on bilateral coordination of the lower limbs during walking, we introduced a split-AS paradigm in young, healthy adults. AS manipulations caused deterioration in the anti-phased stepping pattern and impacted the AS amplitudes for the contralateral arm, suggesting that lower limb coordination is markedly

  13. A coupled oscillator model of disordered interlimb coordination in patients with Parkinson's disease.

    Science.gov (United States)

    Asai, Yoshiyuki; Nomura, Taishin; Sato, Shunsuke; Tamaki, Akira; Matsuo, Yoshimi; Mizukura, Isao; Abe, Kazuo

    2003-02-01

    Coordination between the left and right limbs during cyclic movements, which can be characterized by the amplitude of each limb's oscillatory movement and relative phase, is impaired in patients with Parkinson's disease (PD). A pedaling exercise on an ergometer in a recent clinical study revealed several types of coordination disorder in PD patients. These include an irregular and burst-like amplitude modulation with intermittent changes in its relative phase, a typical sign of chaotic behavior in nonlinear dynamical systems. This clinical observation leads us to hypothesize that emergence of the rhythmic motor behaviors might be concerned with nonlinearity of an underlying dynamical system. In order to gain insight into this hypothesis, we consider a simple hard-wired central pattern generator model consisting of two identical oscillators connected by reciprocal inhibition. In the model, each oscillator acts as a neural half-center controlling movement of a single limb, either left or right, and receives a control input modeling a flow of descending signals from higher motor centers. When these two control inputs are tonic-constant and identical, the model has left-right symmetry and basically exhibits ordered coordination with an alternating periodic oscillation. We show that, depending on the intensities of these two control inputs and on the difference between them that introduces asymmetry into the model, the model can reproduce several behaviors observed in the clinical study. Bifurcation analysis of the model clarifies two possible mechanisms for the generation of disordered coordination in the model: one is the spontaneous symmetry-breaking bifurcation in the model with the left-right symmetry. The other is related to the degree of asymmetry reflecting the difference between the two control inputs. Finally, clinical implications by the model's dynamics are briefly discussed.

  14. Investigation of the Intra- and Inter-Limb Muscle Coordination of Hands-and-Knees Crawling in Human Adults by Means of Muscle Synergy Analysis

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2017-05-01

    Full Text Available To investigate the intra- and inter-limb muscle coordination mechanism of human hands-and-knees crawling by means of muscle synergy analysis, surface electromyographic (sEMG signals of 20 human adults were collected bilaterally from 32 limb related muscles during crawling with hands and knees at different speeds. The nonnegative matrix factorization (NMF algorithm was exerted on each limb to extract muscle synergies. The results showed that intra-limb coordination was relatively stable during human hands-and-knees crawling. Two synergies, one relating to the stance phase and the other relating to the swing phase, could be extracted from each limb during a crawling cycle. Synergy structures during different speeds kept good consistency, but the recruitment levels, durations, and phases of muscle synergies were adjusted to adapt the change of crawling speed. Furthermore, the ipsilateral phase lag (IPL value which was used to depict the inter-limb coordination changed with crawling speed for most subjects, and subjects using the no-limb-pairing mode at low speed tended to adopt the trot-like mode or pace-like mode at high speed. The research results could be well explained by the two-level central pattern generator (CPG model consisting of a half-center rhythm generator (RG and a pattern formation (PF circuit. This study sheds light on the underlying control mechanism of human crawling.

  15. Differences in segmental coordination and postural control in a multi-joint dance movement: développé arabesque.

    Science.gov (United States)

    Bronner, Shaw

    2012-03-01

    Analysis of skill at multiple points on the learning continuum provides insight into how complex limb and postural organization is modified with extended practice. Dancers at three skill levels were compared performing a domain-specific movement (développé arabesque) to identify motor control parameters underlying skill acquisition of a sequential multi-joint trunk and extremity movement. It was hypothesized that general organization would be similar between groups, but that segmental coordination and postural control would differ with skill level. Twenty-seven expert, advanced, and intermediate dancers performed six repetitions of an arabesque sequence with the right limb. Data were acquired with a five-camera motion analysis system. Differences between groups in pelvis and gesture limb displacement, joint coordination patterns, and variability were determined using ANOVA with post hoc comparisons where applicable. Subjects displayed similar movement organization and timing. Differences were found in postural pelvic control and intra- and inter-limb coordination. These differences were most apparent during the arabesque phase. Control of the pelvis appears to be a key area that requires prolonged practice to master.

  16. The amplitude of interlimb cutaneous reflexes in the leg is influenced by fingertip touch and vision during treadmill locomotion.

    Science.gov (United States)

    Forero, Juan; Misiaszek, John E

    2015-06-01

    Light touch at the fingertip has been shown to influence postural control during standing and walking. Interlimb cutaneous reflexes have been proposed to provide a neural link between the upper and lower limbs to assist in interlimb coordination during activities such as walking. In this study, we tested the hypothesis that cutaneous sensory pathways linking the arm and leg will be facilitated if subjects use light touch to assist with postural control during treadmill walking. To test this, interlimb cutaneous reflexes from the median nerve, serving the skin contact region, and radial nerve, serving an irrelevant sensory territory, were tested in the legs of subjects walking on treadmill in an unstable environment. Interlimb cutaneous reflexes were tested while subjects (a) touched or (b) did not touch a stable contact with their fingertip, and while the eyes were either (c) open or (d) closed. Reflexes arising from both nerves were facilitated when vision was removed that was then ameliorated when touch was provided. These changes in reflex amplitude during the eyes closed conditions were mirrored by changes in background muscle activity. We suggest that this facilitation of interlimb reflexes from both nerves arises from a generalized increase in excitability related to the postural anxiety of walking on a treadmill with the eyes closed, which is then restored by the provision of light touch. However, the influence of touch when the eyes were open differed depending upon the nerve stimulated. Radial nerve reflexes in the legs were suppressed when touch was provided, mirroring a suppression in the background muscle activity. In contrast, median nerve reflexes in the leg were larger when touch was provided with the eyes open, despite a suppression of background muscle activity. This nerve-specific effect of touch on the amplitude of the interlimb cutaneous reflexes suggests that touch sensory information from the median nerve was facilitated when that input was

  17. Human Energy Expenditure and Postural Coordination on the Mechanical Horse.

    Science.gov (United States)

    Baillet, Héloïse; Thouvarecq, Régis; Vérin, Eric; Tourny, Claire; Benguigui, Nicolas; Komar, John; Leroy, David

    2017-01-01

    The authors investigated and compared the energy expenditure and postural coordination of two groups of healthy subjects on a mechanical horse at 4 increasing oscillation frequencies. Energy expenditure was assessed from the oxygen consumption, respiratory quotient, and heart rate values, and postural coordination was characterized by relative phase computations between subjects (elbow, head, trunk) and horse. The results showed that the postural coordination of the riders was better adapted (i.e., maintenance of in-phase and antiphase) than that of the nonriders, but the energy expenditure remains the same. Likewise, we observed an energy system shifting only for nonriders (from aerobic to lactic anaerobic mode). Finally, cross-correlations showed a link between energy expenditure and postural coordination in the riders (i.e., effectiveness).

  18. Prenatal Development of Interlimb Motor Learning in the Rat Fetus

    Science.gov (United States)

    Robinson, Scott R.; Kleven, Gale A.; Brumley, Michele R.

    2008-01-01

    The role of sensory feedback in the early ontogeny of motor coordination remains a topic of speculation and debate. On E20 of gestation (the 20th day after conception, 2 days before birth), rat fetuses can alter interlimb coordination after a period of training with an interlimb yoke, which constrains limb movement and promotes synchronized,…

  19. Inter-joint coordination of posture on a seesaw device.

    Science.gov (United States)

    Noé, Frédéric; García-Massó, Xavier; Paillard, Thierry

    2017-06-01

    Even though specific adjustments of the multi-joint control of posture have been observed when posture is challenged, multi-joint coordination on a seesaw device has never been accurately assessed. The current study was conducted in order to investigate the multi-joint coordination when subjects were standing on either a seesaw device or on a stable surface, with the eyes open or closed. Eighteen healthy active subjects were recruited. A principal component analysis and a Self-Organizing Maps analysis were performed on the joint angles in order to detect and characterize dominant coordination patterns. Intermuscular EMG coherence was analysed in order to assess the neurophysiological mechanisms associated with these coordination patterns. The results illustrated a multi-joint organization of posture on both stable ground and on the seesaw, with a higher variability among the individual postural responses observed when standing on the seesaw. These findings challenge the classical assumption of ankle mechanisms as dominating control on seesaw devices and confirm that inter-joint coordination in postural control is strongly modulated by stance conditions. When standing on the seesaw without vision, a decrease in intermuscular coherence was observed without any impact on the joint coordination patterns, likely due to an increase dependence on proprioceptive information. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Shared neural resources between left and right interlimb coordination skills: the neural substrate of abstract motor representations.

    Science.gov (United States)

    Swinnen, S P; Vangheluwe, S; Wagemans, J; Coxon, J P; Goble, D J; Van Impe, A; Sunaert, S; Peeters, R; Wenderoth, N

    2010-02-01

    Functional magnetic resonance imaging was used to reveal the shared neural resources between movements performed with effectors of the left versus right body side. Prior to scanning, subjects extensively practiced a complex coordination pattern involving cyclical motions of the ipsilateral hand and foot according to a 90 degrees out-of-phase coordination mode. Brain activity associated with this (nonpreferred) coordination pattern was contrasted with pre-existing isodirectional (preferred) coordination to extract the learning-related brain networks. To identify the principal candidates for effector-independent movement encoding, the conjunction of training-related activity for left and right limb coordination was determined. A dominantly left-lateralized parietal-to-(pre)motor activation network was identified, with activation in inferior and superior parietal cortex extending into intraparietal sulcus and activation in the premotor areas, including inferior frontal gyrus (pars opercularis). Similar areas were previously identified during observation of complex coordination skills by expert performers. These parietal-premotor areas are principal candidates for abstract (effector-independent) movement encoding, promoting motor equivalence, and they form the highest level in the action representation hierarchy.

  1. Sensory feedback in interlimb coordination

    DEFF Research Database (Denmark)

    Gervasio, Sabata; Voigt, Michael; Kersting, Uwe G.

    2017-01-01

    direct communication between the two sides without the need for the involvement of higher centers. These may also exist in humans since sensory feedback elicited by tibial nerve stimulation on one side (ipsilateral) can affect the muscles activation in the opposite side (contralateral), provoking short......-latency crossed responses (SLCRs). The current study investigated whether contralateral afferent feedback contributes to the mechanism controlling the SLCR in human gastrocnemius muscle. Surface electromyogram, kinematic and kinetic data were recorded from subjects during normal walking and hybrid walking (with.......04). Moreover, estimated spindle secondary afferent and Golgi tendon organ activity were significantly different (P ≤ 0.01) when opposite responses have been observed, that is during normal (facilitation) and hybrid walking (inhibition) conditions. Contralateral sensory feedback, specifically spindle secondary...

  2. Anticipatory Postural Adjustments in a Bimanual Load-Lifting Task in Children with Developmental Coordination Disorder

    Science.gov (United States)

    Jover, Marianne; Schmitz, Christina; Centelles, Laurie; Chabrol, Brigitte; Assaiante, Christine

    2010-01-01

    Aim: Postural control is a fundamental component of action in which deficits have been shown to contribute to motor difficulties in children with developmental coordination disorder (DCD). The purpose of this study was to examine anticipatory postural adjustments (APAs) in children with DCD in a bimanual load-lifting task. Method: Sixteen children…

  3. Coordinated alpha and gamma control of muscles and spindles in movement and posture

    OpenAIRE

    Si eLi; Cheng eZhuang; Manzhao eHao; Xin eHe; Juan Carlos eMarquez Ruiz; Chuanxin Minos Niu; Ning eLan

    2015-01-01

    Mounting evidence suggests that both α and γ motoneurons are active during movement and posture, but how does the central motor system coordinate the α-γ controls in these tasks remains sketchy due to lack of in vivo data. Here a computational model of α-γ control of muscles and spindles was used to investigate α-γ integration and coordination for movement and posture. The model comprised physiologically realistic spinal circuitry, muscles, proprioceptors, and skeletal biomechanics. In the mo...

  4. Postural Adaptations To Supra-postural Tasks in Children With Developmental Coordination Disorder

    Directory of Open Access Journals (Sweden)

    Wade Michael G.

    2011-12-01

    Full Text Available We investigated the effect of varying memory (cognitive demands, and visual (perceptual demands on postural motion. Sixty four children (32 DCD, 32 TDC, 9-to-10 years were volunteers. Each performed separate memory and visual tasks at two levels of difficulty; easy (LD and hard (HD while recording their postural motion. For the memory task, both groups reduced postural sway in the HD condition. For the visual task only the TDC group reduced postural sway in the HD condition; DCD children did not. The DCD group did not reduce postural motion but, in fact, increased motion. We also found several group  task interactions on sway. Our data suggest a weakening of the action linkage between both cognitive and perceptual tasks in children diagnosed with movement difficulties. The data are discussed in the context of limitations in the embodied relationship between posture and both perceptual and cognitive activity.

  5. Effects of kettlebell training on postural coordination and jump performance

    DEFF Research Database (Denmark)

    Jay, Kenneth; Jakobsen, Markus Due; Sundstrup, Emil

    2013-01-01

    ABSTRACT: The aim of this study was to investigate the effectiveness of a worksite intervention using kettlebell training to improve postural reactions to perturbation and jump performance.This single-blind randomized controlled trial involved 40 adults (n=40) from occupations with a high....... The outcome measures were postural reactions to sudden perturbation and maximal countermovement jump height.Compared to the control group, the training group significant decreased stopping time following perturbation (-109ms, 95% CI [-196:-21]). Jump height increased significantly in the training group (1.5cm......, 95% CI [0.5:2.5]), but this was non-significantly different from control.Kettlebell training improves postural reactions to sudden perturbation. Future studies should investigate whether kettlebell training can reduce the risk of low-back injury in occupations with manual material handling or patient...

  6. Interlimb coupling strength scales with movement amplitude.

    Science.gov (United States)

    Peper, C Lieke E; de Boer, Betteco J; de Poel, Harjo J; Beek, Peter J

    2008-05-23

    The relation between movement amplitude and the strength of interlimb interactions was examined by comparing bimanual performance at different amplitude ratios (1:2, 1:1, and 2:1). For conditions with unequal amplitudes, the arm moving at the smaller amplitude was predicted to be more strongly affected by the contralateral arm than vice versa. This prediction was based on neurophysiological considerations and the HKB model of coupled oscillators. Participants performed rhythmic bimanual forearm movements at prescribed amplitude relations. After a brief mechanical perturbation of one arm, the relaxation process back to the initial coordination pattern was examined. This analysis focused on phase adaptations in the unperturbed arm, as these reflect the degree to which the movements of this arm were affected by the coupling influences stemming from the contralateral (perturbed) arm. The thus obtained index of coupling (IC) reflected the relative contribution of the unperturbed arm to the relaxation process. As predicted IC was larger when the perturbed arm moved at a larger amplitude than did the unperturbed arm, indicating that coupling strength scaled with movement amplitude. This result was discussed in relation to previous research regarding sources of asymmetry in coupling strength and the effects of amplitude disparity on interlimb coordination.

  7. Assessing Postural Asymmetry with a Podoscope in Infants with Central Coordination Disturbance

    Science.gov (United States)

    Pyzio-Kowalik, Magdalena; Wojtowicz, Dorota; Skrzek, Anna

    2013-01-01

    The aim of this study was to digitally evaluate the incidence and severity of postural asymmetry in infants with Central Coordination Disturbance (CCD) by using a computer-aided podoscope (PodoBaby) from CQ Elektronik System. A sample of 120 infants aged from 3 months (plus or minus 1 week) to 6 months (plus or minus 1 week) took part in the…

  8. The Nature and Control of Postural Adaptations of Boys with and without Developmental Coordination Disorder

    Science.gov (United States)

    Przysucha, Eryk P.; Taylor, M. Jane; Weber, Douglas

    2008-01-01

    This study compared the nature of postural adaptations and control tendencies, between 7 (n = 9) and 11-year-old boys (n = 10) with Developmental Coordination Disorder (DCD) and age-matched, younger (n = 10) and older (n = 9) peers in a leaning task. Examination of anterior-posterior, medio-lateral, maximum and mean area of sway, and path length…

  9. Postural Responses to a Suprapostural Visual Task among Children with and without Developmental Coordination Disorder

    Science.gov (United States)

    Chen, F. C.; Tsai, C. L.; Stoffregen, T. A.; Wade, M. G.

    2011-01-01

    We sought to determine the effects of varying the perceptual demands of a suprapostural visual task on the postural activity of children with developmental coordination disorder (DCD), and typically developing children (TDC). Sixty-four (32 per group) children aged between 9 and 10 years participated. In a within-participants design, each child…

  10. Postural Adaptations to a Suprapostural Memory Task among Children with and without Developmental Coordination Disorder

    Science.gov (United States)

    Chen, Fu-Chen; Tsai, Chia-Liang; Stoffregen, Thomas A.; Chang, Chihu-Hui; Wade, Michael G.

    2012-01-01

    Aim: The present study investigated the effects of varying the cognitive demands of a memory task (a suprapostural task) while recording postural motion on two groups of children, one diagnosed with developmental coordination disorder (DCD) and an age-matched group of typically developing children. Method: Two groups, each comprising 38 child…

  11. Postural Control in Children With Developmental Coordination Disorder

    OpenAIRE

    Geuze, Reint H.

    2005-01-01

    The development of static balance is a basic characteristic of normal motor development. Most developmental motor tests include a measure of static balance. Children with Developmental Coordination Disorder (DCD) often fail this item. This study reviews the balance problems of children with DCD. The general conclusion is drawn that under normal conditions static balance control is not a problem for children with DCD. Only in difficult, unattended, or novel situations such children seem to suf...

  12. The effect of fatigue on interlimb communication

    DEFF Research Database (Denmark)

    Gervasio, Sabata; Stevenson, Andrew James Thomas; Mrachacz-Kersting, Natalie

    2015-01-01

    was to investigate the possible effect of muscular fatigue on interlimb communication. Eight amateur male soccer players took part to two recording sessions in which they either performed a 90-minute simulated soccer match (SAFT90) or rested (control session). Interlimb communication was investigated by quantifying...

  13. Interaction between interpersonal and postural coordination during frequency scaled rhythmic sway: the role of dance expertise.

    Science.gov (United States)

    Sofianidis, George; Elliott, Mark T; Wing, Alan M; Hatzitaki, Vassilia

    2015-01-01

    Light fingertip touch between partners swaying rhythmically side by side evokes interpersonal synchrony. In non-dancers and dancers swaying to a metronome, we examined the effects of frequency scaling and touch between the partners on both postural (ankle-hip) and inter-personal coordination. In both groups, touch did not interfere with the ankle-hip coordination. In non-dancers but not dancers, increasing frequency resulted in a loss of the ankle-hip coupling that was accompanied by a reduction of the touch mediated interpersonal synchrony. It is suggested that the effect of touch on interpersonal synchrony depends on the reliability of the haptic information sensed at the fingertip and assumes an in phase ankle-hip coupling. These findings have implications in clinical practice when using touch to help balance impaired individuals.

  14. Multimodal Perception and Multicriterion Control of Nested Systems. 1; Coordination of Postural Control and Vehicular Control

    Science.gov (United States)

    Riccio, Gary E.; McDonald, P. Vernon

    1998-01-01

    The purpose of this report is to identify the essential characteristics of goal-directed whole-body motion. The report is organized into three major sections (Sections 2, 3, and 4). Section 2 reviews general themes from ecological psychology and control-systems engineering that are relevant to the perception and control of whole-body motion. These themes provide an organizational framework for analyzing the complex and interrelated phenomena that are the defining characteristics of whole-body motion. Section 3 of this report applies the organization framework from the first section to the problem of perception and control of aircraft motion. This is a familiar problem in control-systems engineering and ecological psychology. Section 4 examines an essential but generally neglected aspect of vehicular control: coordination of postural control and vehicular control. To facilitate presentation of this new idea, postural control and its coordination with vehicular control are analyzed in terms of conceptual categories that are familiar in the analysis of vehicular control.

  15. Altered postural control strategies and sensory organization in children with developmental coordination disorder.

    Science.gov (United States)

    Fong, Shirley S M; Tsang, William W N; Ng, Gabriel Y F

    2012-10-01

    The postural control of children with and without developmental coordination disorder (DCD) was compared under conditions of reduced or conflicting sensory input. Twenty-two children with DCD (16 males, 6 females; mean age 7 years 6 months, SD 1 year 5 months) and 19 children with normal motor development were tested (13 males, 6 females; mean age 6 years 11 months, SD 1 year 1 month). Standing balance, sensory organization and motor control strategy were evaluated using the sensory organization test (SOT). The results revealed that children with DCD had lower composite equilibrium scores (pchildren in the control group. No significant between-group difference in their average somatosensory ratio was observed. Additionally, children with DCD had lower motor strategy scores (swayed more on their hips) than the normal children when forced to depend on vestibular cues alone to balance (pchildren with DCD had deficits in standing balance control in conditions that included reduced or conflicting sensory signals. The visual and vestibular systems tended to be more involved in contributing to the balance deficits than the somatosensory system. Moreover, children with DCD tended to use hip strategy excessively when forced to rely primarily on vestibular signals to maintain postural stability.

  16. Contributions of trunk muscles to anticipatory postural control in children with and without developmental coordination disorder.

    Science.gov (United States)

    Kane, Kyra; Barden, John

    2012-06-01

    Current evidence suggests that movement quality is impacted by postural adjustments made in advance of planned movement. The trunk inevitably plays a key role in these adjustments, by creating a stable foundation for limb movement. The purpose of this study was to examine anticipatory trunk muscle activity during functional tasks in children with and without developmental coordination disorder (DCD). Eleven children with DCD (age 7 to 14 years) and 11 age-matched, typically-developing children performed three tasks: kicking a ball, climbing stairs, and single leg balance. Surface electromyography (EMG) was used to examine the neuromuscular activity of bilateral transversus abdominis/internal oblique, external oblique and L3/4 erector spinae, as well as the right tibialis anterior and rectus femoris muscles. Onset latencies for each muscle were calculated relative to the onset of rectus femoris activity. In comparison to the children with DCD, the typically-developing children demonstrated earlier onsets for right tibialis anterior, bilateral external oblique, and right transversus abdominis/internal oblique muscles. These results suggest that anticipatory postural adjustments may be associated with movement problems in children with DCD, and that timing of both proximal and distal muscles should be considered when designing intervention programs for children with DCD.

  17. Impaired postural control in children with developmental coordination disorder is related to less efficient central as well as peripheral control

    DEFF Research Database (Denmark)

    Speedtsberg, Merete Brink; Christensen, Sofie Bouschinger; Andersen, Ken Kjøller

    2017-01-01

    BACKGROUND: Developmental coordination disorder (DCD) is a neurodevelopmental impairment that affects approximately 6% of children in primary school age. Children with DCD are characterized by impaired postural control. It has yet to be determined what effect peripheral and central neuromuscular...... control has on their balance control. OBJECTIVE: The aim of this study was to investigate the underlying mechanisms to impaired postural control in children with DCD using the rambling-trembling decomposition of the center of pressure (CoP). METHOD: Nine children with DCD (9.0±0.5years, 7 boys, 2 girls...... with fixed support surface. In ML direction children with DCD had a lower relative contribution of rambling to total sway (p=0.013). CONCLUSION: This study showed that impaired postural control in children with DCD is associated with less efficient supraspinal control represented by increased rambling...

  18. Light finger contact concurrently reduces postural sway and enhances signal detection performance in children with developmental coordination disorder.

    Science.gov (United States)

    Chen, Fu-Chen; Tsai, Chia-Liang

    2016-03-01

    The current study examined the effects of light finger touch on postural sway and signal detection performance in children with developmental coordination disorder (DCD). Children with DCD (n=30; 18 boys, 12 girls; age=11.87 ± 0.48 years) and typically developing children (n=30; 14 boys, 16 girls; age=11.73 ± 0.52 years) were recruited from schools in Pintung County, Taiwan. Participants completed a signal detection task under no finger touch (NT) and light finger touch (LT) conditions, while postural sway in both anteroposterior (AP) and mediolateral (ML) axes was recorded. In both conditions, children with DCD exhibited significantly higher levels of postural sway (ppostural sway (ppostural sway was greater among TDC relative to children with DCD (ppostural sway and enhancing signal detection in both groups.

  19. Development of a 3D immersive videogame to improve arm-postural coordination in patients with TBI

    Directory of Open Access Journals (Sweden)

    Cassavaugh Nicholas D

    2011-10-01

    Full Text Available Abstract Background Traumatic brain injury (TBI disrupts the central and executive mechanisms of arm(s and postural (trunk and legs coordination. To address these issues, we developed a 3D immersive videogame-- Octopus. The game was developed using the basic principles of videogame design and previous experience of using videogames for rehabilitation of patients with acquired brain injuries. Unlike many other custom-designed virtual environments, Octopus included an actual gaming component with a system of multiple rewards, making the game challenging, competitive, motivating and fun. Effect of a short-term practice with the Octopus game on arm-postural coordination in patients with TBI was tested. Methods The game was developed using WorldViz Vizard software, integrated with the Qualysis system for motion analysis. Avatars of the participant's hands precisely reproducing the real-time kinematic patterns were synchronized with the simulated environment, presented in the first person 3D view on an 82-inch DLP screen. 13 individuals with mild-to-moderate manifestations of TBI participated in the study. While standing in front of the screen, the participants interacted with a computer-generated environment by popping bubbles blown by the Octopus. The bubbles followed a specific trajectory. Interception of the bubbles with the left or right hand avatar allowed flexible use of the postural segments for balance maintenance and arm transport. All participants practiced ten 90-s gaming trials during a single session, followed by a retention test. Arm-postural coordination was analysed using principal component analysis. Results As a result of the short-term practice, the participants improved in game performance, arm movement time, and precision. Improvements were achieved mostly by adapting efficient arm-postural coordination strategies. Of the 13 participants, 10 showed an immediate increase in arm forward reach and single-leg stance time. Conclusion

  20. Divergent Effects of Cognitive Load on Quiet Stance and Task-Linked Postural Coordination

    Science.gov (United States)

    Mitra, Suvobrata; Knight, Alec; Munn, Alexandra

    2013-01-01

    Performing a cognitive task while maintaining upright stance can lead to increased or reduced body sway depending on tasks and experimental conditions. Because greater sway is commonly taken to indicate loosened postural control, and vice versa, the precise impact of cognitive load on postural stability has remained unclear. In much of the large…

  1. Coordination of opposing sex-specific and core muscle groups regulates male tail posture during Caenorhabditis elegans male mating behavior

    Directory of Open Access Journals (Sweden)

    Sternberg Paul W

    2009-06-01

    Full Text Available Abstract Background To survive and reproduce, animals must be able to modify their motor behavior in response to changes in the environment. We studied a complex behavior of Caenorhabditis elegans, male mating behavior, which provided a model for understanding motor behaviors at the genetic, molecular as well as circuit level. C. elegans male mating behavior consists of a series of six sub-steps: response to contact, backing, turning, vulva location, spicule insertion, and sperm transfer. The male tail contains most of the sensory structures required for mating, in addition to the copulatory structures, and thus to carry out the steps of mating behavior, the male must keep his tail in contact with the hermaphrodite. However, because the hermaphrodite does not play an active role in mating and continues moving, the male must modify his tail posture to maintain contact. We provide a better understanding of the molecular and neuro-muscular pathways that regulate male tail posture during mating. Results Genetic and laser ablation analysis, in conjunction with behavioral assays were used to determine neurotransmitters, receptors, neurons and muscles required for the regulation of male tail posture. We showed that proper male tail posture is maintained by the coordinated activity of opposing muscle groups that curl the tail ventrally and dorsally. Specifically, acetylcholine regulates both ventral and dorsal curling of the male tail, partially through anthelmintic levamisole-sensitive, nicotinic receptor subunits. Male-specific muscles are required for acetylcholine-driven ventral curling of the male tail but dorsal curling requires the dorsal body wall muscles shared by males and hermaphrodites. Gamma-aminobutyric acid activity is required for both dorsal and ventral acetylcholine-induced curling of the male tail and an inhibitory gamma-aminobutyric acid receptor, UNC-49, prevents over-curling of the male tail during mating, suggesting that cross

  2. Parkinson's Disease-Related Impairments in Body Movement, Coordination and Postural Control Mechanisms When Performing 80° Lateral Gaze Shifts.

    Science.gov (United States)

    Bonnet, Cédrick T; Delval, Arnaud; Defebvre, Luc

    2015-09-01

    We investigated early signs of Parkinson's disease-related impairment in mediolateral postural control. Thirty-six participants (18 Hoehn & Yahr stage 2 patients in the off-drug condition and 18 healthy controls) were studied in a stationary gaze condition and when performing 80° lateral gaze shifts at 0.125 and 0.25 Hz. Body sway, coordination and postural control mechanisms were analyzed. All participants performed the visual tasks adequately. The patients were not unstable in the stationary gaze condition. In both groups, mediolateral ankle- and hip-based postural control mechanisms were significantly more active under gaze shift conditions than under the stationary gaze condition. As expected, the patients exhibited significantly greater angular movements of the lower back and significantly lower angular movements of the head (relative to controls) when performing gaze shifts. When considering linear displacements (rather than angular movements), the patients exhibited significantly greater displacements of the lower back and lower, slower displacements of the head than controls under gaze shift conditions. Relative to controls, the patients performed "en block" body movements. Overall, our results show that the patients' ankle- and hip-based mediolateral postural control mechanisms did not adapt to the difficulty of the visual task being performed.

  3. Slowed muscle force production and sensory organization deficits contribute to altered postural control strategies in children with developmental coordination disorder.

    Science.gov (United States)

    Fong, Shirley S M; Ng, Shamay S M; Yiu, Beverley P H L

    2013-09-01

    This study aimed to (1) compare the postural control strategies, sensory organization of balance control, and lower limb muscle performance of children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control strategies, sensory organization parameters and knee muscle performance indices among children with DCD. Fifty-eight DCD-affected children and 46 typically developing children participated in the study. Postural control strategies and sensory organization were evaluated with the sensory organization test (SOT). Knee muscle strength and time to produce maximum muscle torque (at 180°/s) were assessed using an isokinetic machine. Analysis of variance was used to compare the outcome variables between groups, and multiple regression analysis was used to examine the relationships between postural control strategies, sensory organization parameters, and isokinetic indices in children with DCD. The DCD group had significantly lower strategy scores (SOT conditions 5 and 6), lower visual and vestibular ratios, and took a longer time to reach peak torque in the knee flexor muscles than the control group (p>0.05). After accounting for age, sex, and body mass index, the vestibular ratio explained 35.8% of the variance in the strategy score of SOT condition 5 (ppostural control strategy, sensory organization and prolonged duration of muscle force development. Slowed knee muscle force production combined with poor visual and vestibular functioning may result in greater use of hip strategy by children with DCD in sensory challenging environments.

  4. Inter-limb differences in quadriceps strength and volitional activation.

    Science.gov (United States)

    Pietrosimone, Brian G; Park, Chang M; Gribble, Phillip A; Pfile, Kate R; Tevald, Michael A

    2012-01-01

    In this crossover study, we wished to determine if normalized inter-limb differences in strength differed from inter-limb differences in voluntary activation at 30°, 70°, and 90° of knee flexion. We also assessed the relationship between inter-limb differences in torque with the inter-limb differences in activation. Twenty-five healthy volunteers were used for final data analyses; the order of leg tested, joint angle, and measurement technique (isokinetic strength, voluntary activation) were randomly assigned. Quadriceps strength was measured isokinetically at 1.05 rad · s(-1), while quadriceps voluntary activation was assessed via the central activation ratio. Absolute values of inter-limb differences for both measures were calculated by subtracting the non-dominant leg values from those of the dominant leg. Inter-limb isokinetic strength differences were greater than inter-limb central activation ratio differences at all joint angles (P = 0.003). Interestingly, inter-limb deficits between measures were not strongly correlated, suggesting that these measurements may be evaluating completely different phenomena within the neuromuscular system. These measurement techniques may provide unique information regarding neuromuscular function, suggesting that researchers and clinicians must utilize information from both techniques to determine the true clinical nature of inter-limb deficits.

  5. Using Mean Absolute Relative Phase, Deviation Phase and Point-Estimation Relative Phase to Measure Postural Coordination in a Serial Reaching Task

    Directory of Open Access Journals (Sweden)

    Anne K. Galgon, Patricia A. Shewokis

    2016-03-01

    Full Text Available The objectives of this communication are to present the methods used to calculate mean absolute relative phase (MARP, deviation phase (DP and point estimate relative phase (PRP and compare their utility in measuring postural coordination during the performance of a serial reaching task. MARP and DP are derived from continuous relative phase time series representing the relationship between two body segments or joints during movements. MARP is a single measure used to quantify the coordination pattern and DP measures the stability of the coordination pattern. PRP also quantifies coordination patterns by measuring the relationship between the timing of maximal or minimal angular displacements of two segments within cycles of movement. Seven young adults practiced a bilateral serial reaching task 300 times over 3 days. Relative phase measures were used to evaluate inter-joint relationships for shoulder-hip (proximal and hip-ankle (distal postural coordination at early and late learning. MARP, PRP and DP distinguished between proximal and distal postural coordination. There was no effect of practice on any of the relative phase measures for the group, but individual differences were seen over practice. Combined, MARP and DP estimated stability of in-phase and anti-phase postural coordination patterns, however additional qualitative movement analyses may be needed to interpret findings in a serial task. We discuss the strengths and limitations of using MARP and DP and compare MARP and DP to PRP measures in assessing coordination patterns in the context of various types of skillful tasks.

  6. The effects of a concurrent cognitive task on the postural control of young children with and without developmental coordination disorder.

    Science.gov (United States)

    Laufer, Yocheved; Ashkenazi, Tal; Josman, Naomi

    2008-02-01

    The purpose of this study was to examine how dual-task performance affects the center of pressure (COP) sway characteristics and cognitive performance of children with developmental coordination disorder (DCD). Twenty-six children with DCD (mean age-5.1+/-0.59 years) and 20 typically developing children (mean age-5.0+/-0.57 years) participated in the study. The postural task consisted of standing quietly either on a firm or a compliant surface. The cognitive task involved naming simple objects appearing consecutively on a computer screen. Five tests were presented in random order, with the cognitive and the postural tasks tested either separately or concurrently. Mistakes in naming the objects were recorded, as were COP sway characteristics measured with a force-plate. Children with DCD demonstrated higher COP path-length velocity (PLV), and COP amplitude variability, as well as more mistakes in naming the objects in all stance conditions. A concurrent cognitive task increased all sway measures in both groups, with the effect on PLV greater in children with DCD. Cognitive performance was affected by dual tasking only in the control group. Young children with DCD demonstrated greater postural control activity than did the children in the control group during quiet stance, whether performed as a single or a dual task. This difference is accentuated during dual tasking when the children with DCD seem to prioritize the cognitive task.

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

    Science.gov (United States)

    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.

  8. Serotonergic activation of locomotor behavior and posture in one-day old rats.

    Science.gov (United States)

    Swann, Hillary E; Kempe, R Blaine; Van Orden, Ashley M; Brumley, Michele R

    2016-04-01

    The purpose of this study was to determine what dose of quipazine, a serotonergic agonist, facilitates air-stepping and induces postural control and patterns of locomotion in newborn rats. Subjects in both experiments were 1-day-old rat pups. In Experiment 1, pups were restrained and tested for air-stepping in a 35-min test session. Immediately following a 5-min baseline, pups were treated with quipazine (1.0, 3.0, or 10.0 mg/kg) or saline (vehicle control), administered intraperitoneally in a 50 μL injection. Bilateral alternating stepping occurred most frequently following treatment with 10.0 mg/kg quipazine, however the percentage of alternating steps, interlimb phase, and step period were very similar between the 3.0 and 10.0 mg/kg doses. For interlimb phase, the forelimbs and hindlimbs maintained a near perfect anti-phase pattern of coordination, with step period averaging about 1s. In Experiment 2, pups were treated with 3.0 or 10.0 mg/kg quipazine or saline, and then were placed on a surface (open field, unrestrained). Both doses of quipazine resulted in developmentally advanced postural control and locomotor patterns, including head elevation, postural stances, pivoting, crawling, and a few instances of quadrupedal walking. The 3.0 mg/kg dose of quipazine was the most effective at evoking sustained locomotion. Between the 2 experiments, behavior exhibited by the rat pup varied based on testing environment, emphasizing the role that environment and sensory cues exert over motor behavior. Overall, quipazine administered at a dose of 3.0 mg/kg was highly effective at promoting alternating limb coordination and inducing locomotor activity in both testing environments.

  9. Serotonergic Activation of Locomotor Behavior and Posture in One-day Old Rats

    Science.gov (United States)

    Swann, Hillary E.; Kempe, R. Blaine; Van Orden, Ashley M.; Brumley, Michele R.

    2016-01-01

    The purpose of this study was to determine what dose of quipazine, a serotonergic agonist, facilitates air-stepping and induces postural control and patterns of locomotion in newborn rats. Subjects in both experiments were 1-day-old rat pups. In Experiment 1, pups were restrained and tested for air-stepping in a 35-min test session. Immediately following a 5-min baseline, pups were treated with quipazine (1.0, 3.0, or 10.0 mg/kg) or saline (vehicle control), administered intraperitoneally in a 50 microliter injection. Bilateral alternating stepping occurred most frequently following treatment with 10.0 mg/kg quipazine, however the percentage of alternating steps, interlimb phase, and step period were very similar between the 3.0 and 10.0 mg/kg doses. For interlimb phase, the forelimbs and hindlimbs maintained a near perfect anti-phase pattern of coordination, with step period averaging about 1 second. In Experiment 2, pups were treated with 3.0 or 10.0 mg/kg quipazine or saline, and then were placed on a surface (open field, unrestrained). Both doses of quipazine resulted in developmentally advanced postural control and locomotor patterns, including head elevation, postural stances, pivoting, crawling, and a few instances of quadrupedal walking. The 3.0 mg/kg dose of quipazine was the most effective at evoking sustained locomotion. Between the 2 experiments, behavior exhibited by the rat pup varied based on testing environment, emphasizing the role that environment and sensory cues exert over motor behavior. Overall, quipazine administered at a dose of 3.0 mg/kg was highly effective at promoting alternating limb coordination and inducing locomotor activity in both testing environments. PMID:26795091

  10. Using Mean Absolute Relative Phase, Deviation Phase and Point-Estimation Relative Phase to Measure Postural Coordination in a Serial Reaching Task.

    Science.gov (United States)

    Galgon, Anne K; Shewokis, Patricia A

    2016-03-01

    The objectives of this communication are to present the methods used to calculate mean absolute relative phase (MARP), deviation phase (DP) and point estimate relative phase (PRP) and compare their utility in measuring postural coordination during the performance of a serial reaching task. MARP and DP are derived from continuous relative phase time series representing the relationship between two body segments or joints during movements. MARP is a single measure used to quantify the coordination pattern and DP measures the stability of the coordination pattern. PRP also quantifies coordination patterns by measuring the relationship between the timing of maximal or minimal angular displacements of two segments within cycles of movement. Seven young adults practiced a bilateral serial reaching task 300 times over 3 days. Relative phase measures were used to evaluate inter-joint relationships for shoulder-hip (proximal) and hip-ankle (distal) postural coordination at early and late learning. MARP, PRP and DP distinguished between proximal and distal postural coordination. There was no effect of practice on any of the relative phase measures for the group, but individual differences were seen over practice. Combined, MARP and DP estimated stability of in-phase and anti-phase postural coordination patterns, however additional qualitative movement analyses may be needed to interpret findings in a serial task. We discuss the strengths and limitations of using MARP and DP and compare MARP and DP to PRP measures in assessing coordination patterns in the context of various types of skillful tasks. Key pointsMARP, DP and PRP measures coordination between segments or joint anglesAdvantages and disadvantages of each measure should be considered in relationship to the performance taskMARP and DP may capture coordination patterns and stability of the patterns during discrete tasks or phases of movements within a taskPRP and SD or PRP may capture coordination patterns and

  11. Frequency-induced changes in interlimb interactions: increasing manifestations of closed-loop control.

    Science.gov (United States)

    de Boer, Betteco J; Peper, C Lieke E; Beek, Peter J

    2011-06-20

    In bimanual coordination, interactions between the limbs result in attraction to in-phase and antiphase coordination. Increasing movement frequency leads to decreasing stability of antiphase coordination, often resulting in a transition to the more stable in-phase pattern. It is unknown, however, how this frequency-induced loss of stability is engendered in terms of the interlimb interactions underwriting bimanual coordination. The present study was conducted to help resolve this issue. Using an established method (based on comparison of various unimanual and bimanual tasks involving both passive and active movements), three sources of interlimb interaction were dissociated: (1) integrated timing of feedforward signals, (2) afference-based correction of relative phase errors, and (3) phase entrainment by contralateral afference. Results indicated that phase entrainment strength remained unaffected by frequency and that the stabilizing effects of error correction and integrated timing decreased with increasing frequency. Their contributions, however, reflected an interesting interplay as frequency increased. For moderate frequencies coordinative stability was predominantly secured by integrated timing processes. However, at high frequencies, the stabilization of the antiphase pattern required combined contributions of both integrated timing and error correction. In sum, increasing frequency was found to induce a shift from predominantly open-loop control to more closed-loop control. The results may be accounted for by means of an internal forward model for sensorimotor integration in which the sensory signals are compared to values predicted on the basis of efference copies.

  12. Influence of Botulinum Toxin Therapy on Postural Control and Lower Limb Intersegmental Coordination in Children with Spastic Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Bernard Dan

    2013-01-01

    Full Text Available Botulinum toxin injections may significantly improve lower limb kinematics in gait of children with spastic forms of cerebral palsy. Here we aimed to analyze the effect of lower limb botulinum toxin injections on trunk postural control and lower limb intralimb (intersegmental coordination in children with spastic diplegia or spastic hemiplegia (GMFCS I or II. We recorded tridimensional trunk kinematics and thigh, shank and foot elevation angles in fourteen 3–12 year-old children with spastic diplegia and 14 with spastic hemiplegia while walking either barefoot or with ankle-foot orthoses (AFO before and after botulinum toxin infiltration according to a management protocol. We found significantly greater trunk excursions in the transverse plane (barefoot condition and in the frontal plane (AFO condition. Intralimb coordination showed significant differences only in the barefoot condition, suggesting that reducing the degrees of freedom may limit the emergence of selective coordination. Minimal relative phase analysis showed differences between the groups (diplegia and hemiplegia but there were no significant alterations unless the children wore AFO. We conclude that botulinum toxin injection in lower limb spastic muscles leads to changes in motor planning, including through interference with trunk stability, but a combination of therapies (orthoses and physical therapy is needed in order to learn new motor strategies.

  13. Earth-referenced handrail contact facilitates interlimb cutaneous reflexes during locomotion.

    Science.gov (United States)

    Lamont, Erin V; Zehr, E Paul

    2007-07-01

    The purpose of this study was to investigate whether the gating of interlimb cutaneous reflexes is altered by holding an earth-referenced handrail during locomotion. In the first experiment, subjects performed locomotor tasks of varying difficulty (level walking, incline walking, and stair climbing) while lightly holding an earth-referenced rail. In the second experiment, the extent of rail contact and nature of the rail stability (e.g., fixed vs. mobile rail) were varied while subjects performed incline walking. Cutaneous reflexes were evoked by delivering trains of electrical stimulation to the sural nerve at the ankle. EMG data were collected continuously from muscles in the upper and lower limbs and trunk. Results showed that modulation of reflexes across the body changed when the rail was held. Most interestingly, a facilitatory reflex in the shoulder extensor posterior deltoid emerged during swing phase only when subjects held a rail. This facilitatory reflex was largest during the more challenging tasks of incline walking and stair climbing, A similar reflex facilitation was observed in the elbow extensor triceps brachii. The observed facilitation of reflexes in triceps brachii and posterior deltoid was specifically expressed only when subjects held an earth-referenced rail. This suggests that interlimb reflexes in arm extensors may be enhanced to make use of a supportive handrail for stability during gait. Therefore, holding a rail may cause global changes in reflex thresholds across the body that may have widespread functional relevance for assisting in the maintenance of postural stability during locomotion.

  14. Postural Responses to a Moving Room in Children with and without Developmental Coordination Disorder

    Science.gov (United States)

    Chung, Hyun Chae; Stoffregen, Thomas A.

    2011-01-01

    Children (10 or 11 years old) with and without developmental coordination disorder (DCD) were exposed to imposed optic flow in a moving room. We manipulated the amplitude and frequency of oscillatory room motion, and we evaluated the coupling of standing body sway with room oscillations. The results revealed that standing sway of both children…

  15. Bimanual coordination and musical experience : The role of intrinsic dynamics and behavioral information

    NARCIS (Netherlands)

    Verheul, M.H.G.; Geuze, RH

    Rhythmic interlimb coordination arises from the interaction of intrinsic dynamics and behavioral information, that is, intention, memory, or external information specifying the required coordination pattern. This study investigates the influence of the content of memorized behavioral information on

  16. Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

    Science.gov (United States)

    Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

    2016-09-01

    Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002balance and strength training programs should take into account age-specific alterations in muscle activity.

  17. Rhythmic coordination dynamics in children with and without a developmental coordination disorder

    NARCIS (Netherlands)

    Volman, Michiel Joannes Maria

    1997-01-01

    The aim of the present thesis is to examine the intrinsic dynamics of rhythmic coordinated actions in children with and without DCD by testing the stability of these patterns. Two basically different coordination systems are examined, namely, rhythmic interlimb coordination and rhythmic

  18. Rhythmic coordination dynamics in children with and without a developmental coordination disorder

    NARCIS (Netherlands)

    Volman, Michiel Joannes Maria

    1997-01-01

    The aim of the present thesis is to examine the intrinsic dynamics of rhythmic coordinated actions in children with and without DCD by testing the stability of these patterns. Two basically different coordination systems are examined, namely, rhythmic interlimb coordination and rhythmic perception-a

  19. Intentional switches between bimanual coordination patterns are primarily effectuated by the nondominant hand

    NARCIS (Netherlands)

    de Poel, HJ; Peper, CE; Beek, PJ

    2006-01-01

    Based on indications that hand dominance is characterized by asymmetrical interlimb coupling strength (with the dominant hand exerting stronger influences on the nondominant hand than vice versa), intentional switches between rhythmic bimanual coordination patterns were predicted to be mediated prim

  20. The Assessment of Postural Control, Reflex Integration, and Bilateral Motor Coordination of Young Handicapped Children. Final Report.

    Science.gov (United States)

    DeGangi, Georgia; Larsen, Lawrence A.

    A measurement device, Assessment of Sensorimotor Integration in Preschool Children, was developed to assess postural control, reflex integration and bilateral motor integration in developmentally delayed children (3 to 5 years old). The test was administered to 113 normal children and results were compared with data collected on 23 developmentally…

  1. The efficacy of the Microsoft Kinect(TM) to assess human bimanual coordination.

    Science.gov (United States)

    Liddy, Joshua J; Zelaznik, Howard N; Huber, Jessica E; Rietdyk, Shirley; Claxton, Laura J; Samuel, Arjmand; Haddad, Jeffrey M

    2016-06-28

    The Microsoft Kinect has been used in studies examining posture and gait. Despite the advantages of portability and low cost, this device has not been used to assess interlimb coordination. Fundamental insights into movement control, variability, health, and functional status can be gained by examining coordination patterns. In this study, we investigated the efficacy of the Microsoft Kinect to capture bimanual coordination relative to a research-grade motion capture system. Twenty-four healthy adults performed coordinated hand movements in two patterns (in-phase and antiphase) at eight movement frequencies (1.00-3.33 Hz). Continuous relative phase (CRP) and discrete relative phase (DRP) were used to quantify the means (mCRP and mDRP) and variability (sdCRP and sdDRP) of coordination patterns. Between-device agreement was assessed using Bland-Altman bias with 95 % limits of agreement, concordance correlation coefficients (absolute agreement), and Pearson correlation coefficients (relative agreement). Modest-to-excellent relative and absolute agreements were found for mCRP in all conditions. However, mDRP showed poor agreement for the in-phase pattern at low frequencies, due to large between-device differences in a subset of participants. By contrast, poor absolute agreement was observed for both sdCRP and sdDRP, while relative agreement ranged from poor to excellent. Overall, the Kinect captures the macroscopic patterns of bimanual coordination better than coordination variability.

  2. The effect of fatigue on interlimb communication

    DEFF Research Database (Denmark)

    Gervasio, Sabata; Stevenson, Andrew James Thomas; Mrachacz-Kersting, Natalie

    2015-01-01

    Performing repeated motor tasks during a volleyball, basketball, or soccer game can lead to muscular fatigue, inducing a decrease in the capacity of a muscle to generate force, changes in motor coordination, and an alteration in motor performance. These changes have been attributed to an elevated...... risk of musculoskeletal injury. Little is known about if and how fatigue affects the coordination between the two legs during a long lasting game, and whether this could be one of the causes behind the increased occurrence of injuries towards the end of a game. The aim of the present study...... and control session. MVC was quantified while the participants performed a plantarflexion on a force platform, with the ankle and knee joints fastened at 90[[unable to display character: ⁰

  3. Interlimb Reflexes Induced by Electrical Stimulation of Cutaneous Nerves after Spinal Cord Injury.

    Science.gov (United States)

    Butler, Jane E; Godfrey, Sharlene; Thomas, Christine K

    2016-01-01

    Whether interlimb reflexes emerge only after a severe insult to the human spinal cord is controversial. Here the aim was to examine interlimb reflexes at rest in participants with chronic (>1 year) spinal cord injury (SCI, n = 17) and able-bodied control participants (n = 5). Cutaneous reflexes were evoked by delivering up to 30 trains of stimuli to either the superficial peroneal nerve on the dorsum of the foot or the radial nerve at the wrist (5 pulses, 300 Hz, approximately every 30 s). Participants were instructed to relax the test muscles prior to the delivery of the stimuli. Electromyographic activity was recorded bilaterally in proximal and distal arm and leg muscles. Superficial peroneal nerve stimulation evoked interlimb reflexes in ipsilateral and contralateral arm and contralateral leg muscles of SCI and control participants. Radial nerve stimulation evoked interlimb reflexes in the ipsilateral leg and contralateral arm muscles of control and SCI participants but only contralateral leg muscles of control participants. Interlimb reflexes evoked by superficial peroneal nerve stimulation were longer in latency and duration, and larger in magnitude in SCI participants. Interlimb reflex properties were similar for both SCI and control groups for radial nerve stimulation. Ascending interlimb reflexes tended to occur with a higher incidence in participants with SCI, while descending interlimb reflexes occurred with a higher incidence in able-bodied participants. However, the overall incidence of interlimb reflexes in SCI and neurologically intact participants was similar which suggests that the neural circuitry underlying these reflexes does not necessarily develop after central nervous system injury.

  4. Coordination pattern adaptability: energy cost of degenerate behaviors.

    Directory of Open Access Journals (Sweden)

    Ludovic Seifert

    Full Text Available This study investigated behavioral adaptability, which could be defined as a blend between stability and flexibility of the limbs movement and their inter-limb coordination, when individuals received informational constraints. Seven expert breaststroke swimmers performed three 200-m in breaststroke at constant submaximal intensity. Each trial was performed randomly in a different coordination pattern: 'freely-chosen', 'maximal glide' and 'minimal glide'. Two underwater and four aerial cameras enabled 3D movement analysis in order to assess elbow and knee angles, elbow-knee pair coordination, intra-cyclic velocity variations of the center of mass, stroke rate and stroke length and inter-limb coordination. The energy cost of locomotion was calculated from gas exchanges and blood lactate concentration. The results showed significantly higher glide, intra-cyclic velocity variations and energy cost under 'maximal glide' compared to 'freely-chosen' instructional conditions, as well as higher reorganization of limb movement and inter-limb coordination (p<0.05. In the 'minimal glide' condition, the swimmers did not show significantly shorter glide and lower energy cost, but they exhibited significantly lower deceleration of the center of mass, as well as modified limb movement and inter-limb coordination (p<0.05. These results highlight that a variety of structural adaptations can functionally satisfy the task-goal.

  5. Nature of spatial coupling in children with and without developmental coordination disorder in ball catching.

    Science.gov (United States)

    Przysucha, Eryk P; Maraj, Brian K V

    2013-07-01

    The nature of intra- and interlimb (bimanual) coordination was examined in ten boys with (M = 10.5 years, SD = 1.0) and without DCD (M = 10.8 years, SD = .9) in a two-handed catching task. Children with developmental coordination disorder (DCD) caught significantly fewer balls (MDCD = 56%, SD = 17.6 vs. MnoDCD = 93%, SD = 7.5), and both groups solved the "degrees of freedom problem" differently at intralimb level of coordination. Typically developing children coupled and decoupled the respective spatial relations, whereas the majority of children with DCD segmented their actions. At interlimb level, both groups exhibited a comparable degree of spatial symmetry. However, individual profiles also showed that children with varying degrees of movement issues exhibited movement patterns that were qualitatively and functionally diverse. Overall, in the context of previous research on interlimb coordination it appears that spatial, in addition to temporal organization, may be jeopardized in at least some children with DCD.

  6. Dynamic Control of Posture Across Locomotor Tasks

    OpenAIRE

    Earhart, Gammon M.

    2013-01-01

    Successful locomotion depends on postural control to establish and maintain appropriate postural orientation of body segments relative to one another and to the environment, and to ensure dynamic stability of the moving body. This paper provides a framework for considering dynamic postural control, highlighting the importance of coordination, consistency, and challenges to postural control posed by various locomotor tasks such as turning and backward walking. The impacts of aging and various ...

  7. Functional Neuroanatomy for Posture and Gait Control

    OpenAIRE

    Takakusaki, Kaoru

    2017-01-01

    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 p...

  8. Development of temporal and spatial bimanual coordination during childhood

    NARCIS (Netherlands)

    Boer, de B.J.; Peper, C.E.; Beek, P.J.

    2012-01-01

    Developmental changes in bimanual coordination were examined in four age groups: 6/7, 10/11, 14/15 years, and young adults. Temporal coupling was assessed through the stabilizing contributions of interlimb interactions related to planning, error correction, and reflexes during rhythmic wrist movemen

  9. Interlimb reflexes following ipsilateral knee joint rotations are suppressed in an unstable walking environment

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Sinkjær, Thomas;

    2015-01-01

    . To test this, interlimb reflexes were elicited in participants (n = 6) by either iKnee extension rotations during the late stance phase (50%) of the gait cycle or iKnee flexion rotations during the mid-swing phase (80%). The iKnee perturbations were applied while the participants walked normally...

  10. Interlimb communication following unexpected changes in treadmill velocity during human walking

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Sinkjær, Thomas;

    2015-01-01

    applied to the ipsilateral leg (iKnee) during the late stance phase of human gait (Stevenson et al. 2013). This interlimb reflex likely acts to slow the forward progression of the body in order to maintain dynamic stability following the perturbations. We examined this hypothesis by unexpectedly...

  11. Neuromechanical tuning of nonlinear postural control dynamics

    Science.gov (United States)

    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.

  12. Identifying leading joint strategies in a bimanual coordination task: does coordination stability depend on leading joint strategy?

    Science.gov (United States)

    Rodriguez, Tiffany M; Buchanan, John J; Ketcham, Caroline J

    2010-01-01

    The authors sought to determine if principles of the Leading Joint Hypothesis, when applied to a multijoint, bimanual coordination task, could provide insight into the contribution of intralimb dynamics to interlimb coordination. Participants repetitively traced ellipse templates with an isodirectional motion of the end effectors (both hands moving counterclockwise [CCW]) at two cycling frequencies. Ellipse templates were oriented either tilted right or tilted left, yielding a total of 4 left arm-right arm leading-joint combinations. Analysis of torque sign and impulse data indicated that the 4 ellipse-tracing conditions resulted in 4 distinct left arm-right arm leading-joint combinations: 2 conditions with similar leading joints and 2 conditions with different leading joints. Isodirectional CCW ellipse tracing was more stable when produced with similar leading joints compared with when produced with different leading joints. The authors discuss results within the context of intralimb control contributions to the stability of interlimb coordination patterns.

  13. Interlimb reflexes following ipsilateral knee joint rotations are suppressed in an unstable walking environment

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Sinkjær, Thomas

    2015-01-01

    Knee) extension rotations during walking contribute to slowing the forward progression of the body in order to maintain dynamic stability following the perturbation (Stevenson et al., 2015). However, little is known about how such interlimb reflexes are modulated in an unstable walking environment. Based....... To test this, interlimb reflexes were elicited in participants (n = 6) by either iKnee extension rotations during the late stance phase (50%) of the gait cycle or iKnee flexion rotations during the mid-swing phase (80%). The iKnee perturbations were applied while the participants walked normally......) in the unstable walking condition following both types of iKnee perturbations, while the cSOL reflexes remained unchanged. Consistent with previous studies, these preliminary results suggest that challenging dynamic stability during walking leads to specific changes in reflex amplitudes that are not related...

  14. Interlimb coordination during forward walking is largely preserved in backward walking in children with cerebral palsy

    NARCIS (Netherlands)

    Meyns, P.; Molenaers, G.; Desloovere, K.; Duysens, J.E.J.

    2014-01-01

    OBJECTIVE: Limb kinematics in backward walking (BW) are essentially those of forward walking (FW) in reverse. It has been argued that subcortical mechanisms could underlie both walking modes. METHODS: Therefore, we tested whether participants with supraspinal/cortical deficits (i.e. cerebral palsy)

  15. Interlimb coordination during forward and backward walking in primary school-aged children.

    NARCIS (Netherlands)

    Meyns, P.; Desloovere, K.; Molenaers, G.; Swinnen, S.P.; Duysens, J.E.J.

    2013-01-01

    Previous studies comparing forward (FW) and backward (BW) walking suggested that the leg kinematics in BW were essentially those of FW in reverse. This led to the proposition that in adults the neural control of FW and BW originates from the same basic neural circuitry. One aspect that has not recei

  16. Developmental plasticity of coordinated action patterns in the perinatal rat.

    Science.gov (United States)

    Brumley, Michele R; Kauer, Sierra D; Swann, Hillary E

    2015-05-01

    Some of the most simple, stereotyped, reflexive, and spinal-mediated motor behaviors expressed by animals display a level of flexibility and plasticity that is not always recognized. We discuss several examples of how coordinated action patterns have been shown to be flexible and adaptive in response to sensory feedback. We focus on interlimb and intralimb coordination during the expression of two action patterns (stepping and the leg extension response) in newborn rats, as well as interlimb motor learning. We also discuss the idea that the spinal cord is a major site for supporting plasticity in the developing motor system. An implication of this research is that normally occurring sensory stimulation during the perinatal period influences the typical development and expression of action patterns, and that exploiting the developmental plasticity of the motor system may lead to improved strategies for promoting recovery of function in human infants with motor disorders.

  17. On the assessment of coordination between upper extremities: towards a common language between rehabilitation engineers, clinicians and neuroscientists.

    Science.gov (United States)

    Shirota, Camila; Jansa, Jelka; Diaz, Javier; Balasubramanian, Sivakumar; Mazzoleni, Stefano; Borghese, N Alberto; Melendez-Calderon, Alejandro

    2016-09-08

    Well-developed coordination of the upper extremities is critical for function in everyday life. Interlimb coordination is an intuitive, yet subjective concept that refers to spatio-temporal relationships between kinematic, kinetic and physiological variables of two or more limbs executing a motor task with a common goal. While both the clinical and neuroscience communities agree on the relevance of assessing and quantifying interlimb coordination, rehabilitation engineers struggle to translate the knowledge and needs of clinicians and neuroscientists into technological devices for the impaired. The use of ambiguous definitions in the scientific literature, and lack of common agreement on what should be measured, present large barriers to advancements in this area. Here, we present the different definitions and approaches to assess and quantify interlimb coordination in the clinic, in motor control studies, and by state-of-the-art robotic devices. We then propose a taxonomy of interlimb activities and give recommendations for future neuroscience-based robotic- and sensor-based assessments of upper limb function that are applicable to the everyday clinical practice. We believe this is the first step towards our long-term goal of unifying different fields and help the generation of more consistent and effective tools for neurorehabilitation.

  18. Dynamic control of posture across locomotor tasks.

    Science.gov (United States)

    Earhart, Gammon M

    2013-09-15

    Successful locomotion depends on postural control to establish and maintain appropriate postural orientation of body segments relative to one another and to the environment and to ensure dynamic stability of the moving body. This article provides a framework for considering dynamic postural control, highlighting the importance of coordination, consistency, and challenges to postural control posed by various locomotor tasks, such as turning and backward walking. The impacts of aging and various movement disorders on postural control are discussed broadly in an effort to provide a general overview of the field and recommendations for assessment of dynamic postural control across different populations in both clinical and research settings. Suggestions for future research on dynamic postural control during locomotion also are provided and include discussion of opportunities afforded by new and developing technologies, the need for long-term monitoring of locomotor performance in everyday activities, gaps in our knowledge of how targeted intervention approaches modify dynamic postural control, and the relative paucity of literature regarding dynamic postural control in movement disorder populations other than Parkinson's disease.

  19. Neuromuscular Control and Coordination during Cycling

    Science.gov (United States)

    Li, Li

    2004-01-01

    The neuromuscular control aspect of cycling has been investigated through the effects of modifying posture and cadence. These studies show that changing posture has a more profound influence on neuromuscular coordination than does changing slope. Most of the changes with standing posture occur late in the downstroke: increased ankle and knee joint…

  20. Interlimb communication to the knee flexors during walking in humans

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Andersen, Jacob Buus;

    2013-01-01

    in the right leg following unexpected unilateral knee joint rotations during locomotion in either the flexion or extension direction. Strong reflex responses in the contralateral biceps femoris (cBF) muscle with a mean onset latency of 76 ± 6 ms were evoked only from ipsilateral knee extension joint rotations......A strong coordination between the two legs is important for maintaining a symmetric gait pattern and adapting to changes in the external environment. In humans as well as animals, receptors arising from the quadriceps muscle group influence the activation of ipsilateral muscles. Moreover, strong...... that the cBF reflex response may be a preparation of the contralateral leg for early load bearing, slowing the forward progression of the body in order to maintain dynamic equilibrium during walking....

  1. Effects of varying inter-limb spacing to limb length ratio in metachronal swimming

    Science.gov (United States)

    Lai, Hong Kuan; Merkel, Rachael; Santhanakrishnan, Arvind

    2016-11-01

    Crustaceans such as shrimp, krill and crayfish swim by rhythmic paddling of four to five pairs of closely spaced limbs. Each pair is phase-shifted in time relative to the neighboring pair, resulting in a metachronal wave that travels in the direction of animal motion. The broad goal of this study is to investigate how the mechanical design of the swimming limbs affect scalability of metachronal swimming in terms of limb-based Reynolds number (Re). A scaled robotic model of metachronal paddling was developed, consisting of four pairs of hinged acrylic plates actuated using stepper motors that were immersed in a rectangular tank containing water-glycerin fluid medium. 2D PIV measurements show that the propulsive jets transition from being primarily horizontal (thrust-producing direction) at Re of order 10 to angled vertically at Re of order 100. The ratio of inter-limb spacing to limb length among metachronal swimming organisms ranges between 0.2 to 0.65. 2D PIV will be used to examine the jets generated between adjacent limbs for varying inter-limb spacing to limb length ratios. The effect of increasing this ratio to beyond the biologically observed range will be discussed.

  2. Functional Neuroanatomy for Posture and Gait Control.

    Science.gov (United States)

    Takakusaki, Kaoru

    2017-01-01

    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.

  3. 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.

  4. Functional Neuroanatomy for Posture and Gait Control

    Science.gov (United States)

    Takakusaki, Kaoru

    2017-01-01

    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. PMID:28122432

  5. 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.

  6. Normal inter-limb differences during the straight leg raise neurodynamic test: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Boyd Benjamin S

    2012-12-01

    Full Text Available Abstract Background The straight leg raise (SLR neurodynamic test is commonly used to examine the sensitivity of the lower quarter nervous system to movement. Range of motion during the SLR varies considerably, due to factors such as age, sex and activity level. Knowing intra-individual, inter-limb differences may provide a normative measure that is not influenced by such demographic characteristics. This study aimed to determine normal asymmetries between limbs in healthy, asymptomatic individuals during SLR testing and the relationship of various demographic characteristics. Methods The limb elevation angle was measured using an inclinometer during SLR neurodynamic testing that involved pre-positioning the ankle in plantar flexion (PF/SLR and neutral dorsiflexion (DF/SLR. Phase 1 of the study included 20 participants where the ankle was positioned using an ankle brace replicating research testing conditions. Phase 2 included 20 additional participants where the ankle was manually positioned to replicate clinical testing conditions. Results The group average range of motion during PF/SLR was 57.1 degrees (SD: 16.8 degrees on the left and 56.7 degrees (SD: 17.2 degrees on the right while during DF/SLR the group average was 48.5 degrees (SD: 16.1 degrees on the left and 48.9 degrees (SD: 16.4 degrees on the right. The range of motion during SLR was moderately correlated to weight (−0.40 to −0.52, body mass index (−0.41 to −0.52, sex (0.40 to 0.42 and self-reported activity level (0.50 to 0.57. Intra-individual differences between limbs for range of motion during PF/SLR averaged 5.0 degrees (SD: 3.5 degrees (95% CI: 3.8 degrees, 6.1 degrees and during DF/SLR averaged 4.1 degrees (SD: 3.2 degrees (95% CI: 3.1 degrees, 5.1 degrees but were not correlated with any demographic characteristic. There were no significant differences between Phase 1 and Phase 2. Conclusions Overall range of motion during SLR was related to sex, weight, BMI and

  7. Development of postural adjustments during reaching in typically developing infants from 4 to 18 months

    NARCIS (Netherlands)

    van Balen, Lieke C.; Dijkstra, Linze Jaap; Hadders-Algra, Mijna

    Knowledge on the development of postural adjustments during infancy, in particular on the development of postural muscle coordination, is limited. This study aimed at the evaluation of the development of postural control during reaching in a supported sitting condition. Eleven typically developing

  8. Neural adaptations associated with interlimb transfer in a ballistic wrist flexion task.

    Directory of Open Access Journals (Sweden)

    Kathy L Ruddy

    2016-05-01

    Full Text Available Cross education is the process whereby training of one limb gives rise to increases in the subsequent performance of its opposite counterpart. The execution of many unilateral tasks is associated with increased excitability of corticospinal projections from primary motor cortex (M1 to the opposite limb. It has been proposed that these effects are causally related. Our aim was to establish whether changes in corticospinal excitability arising from prior training of the opposite limb determine levels of interlimb transfer. We used three vision conditions shown previously to modulate the excitability of corticospinal projections to the inactive (right limb during wrist flexion movements performed by the training (left limb. These were: mirrored visual feedback of the training limb; no visual feedback of either limb; and visual feedback of the inactive limb. Training comprised 300 discrete, ballistic wrist flexion movements executed as rapidly as possible. Performance of the right limb on the same task was assessed prior to, at the mid point of, and following left limb training. There was no evidence that variations in the excitability of corticospinal projections (assessed by transcranial magnetic stimulation (TMS to the inactive limb were associated with, or predictive of, the extent of interlimb transfer that was expressed. There were however associations between alterations in muscle activation dynamics observed for the untrained limb, and the degree of positive transfer that arose from training of the opposite limb. The results suggest that the acute adaptations that mediate the bilateral performance gains realised through unilateral practice of this ballistic wrist flexion task are mediated by neural elements other than those within M1 that are recruited at rest by single-pulse TMS.

  9. Neural Adaptations Associated with Interlimb Transfer in a Ballistic Wrist Flexion Task.

    Science.gov (United States)

    Ruddy, Kathy L; Rudolf, Anne K; Kalkman, Barbara; King, Maedbh; Daffertshofer, Andreas; Carroll, Timothy J; Carson, Richard G

    2016-01-01

    Cross education is the process whereby training of one limb gives rise to increases in the subsequent performance of its opposite counterpart. The execution of many unilateral tasks is associated with increased excitability of corticospinal projections from primary motor cortex (M1) to the opposite limb. It has been proposed that these effects are causally related. Our aim was to establish whether changes in corticospinal excitability (CSE) arising from prior training of the opposite limb determine levels of interlimb transfer. We used three vision conditions shown previously to modulate the excitability of corticospinal projections to the inactive (right) limb during wrist flexion movements performed by the training (left) limb. These were: (1) mirrored visual feedback of the training limb; (2) no visual feedback of either limb; and (3) visual feedback of the inactive limb. Training comprised 300 discrete, ballistic wrist flexion movements executed as rapidly as possible. Performance of the right limb on the same task was assessed prior to, at the mid point of, and following left limb training. There was no evidence that variations in the excitability of corticospinal projections (assessed by transcranial magnetic stimulation (TMS)) to the inactive limb were associated with, or predictive of, the extent of interlimb transfer that was expressed. There were however associations between alterations in muscle activation dynamics observed for the untrained limb, and the degree of positive transfer that arose from training of the opposite limb. The results suggest that the acute adaptations that mediate the bilateral performance gains realized through unilateral practice of this ballistic wrist flexion task are mediated by neural elements other than those within M1 that are recruited at rest by single-pulse TMS.

  10. Electronic spinal posture detection

    OpenAIRE

    Thoné, Jef; Jourand, Philippe; Puers, Robert

    2009-01-01

    A wearable automatic monitoring system for back posture has been developed and tested. Making use of only five accelerometers placed on strategic locations on the back, a stand alone system enables detection, logging and feedback of the patient’s posture. The system enables alerting the patient of a bad posture, or long-term data logging to analyze the patient’s posture over a prolonged period.

  11. Postural Synergies and Their Development

    Directory of Open Access Journals (Sweden)

    Mark L. Latash

    2005-01-01

    Full Text Available The recent developments of a particular approach to analyzing motor synergies based on the principle of motor abundance has allowed a quantitative assessment of multieffector coordination in motor tasks involving anticipatory adjustments to self-triggered postural perturbations and in voluntary posturalsway. This approach, the uncontrolled manifold (UCM hypothesis, is based on an assumption that the central nervous system organizes covariation of elemental variables to stabilize important performance variables in a task-specific manner. In particular, this approach has been used to demonstrate and to assess the emergence of synergies and their modification with motor practice in typical persons and persons with Down syndrome. The framework of the UCM hypothesis allows the formulation of testable hypotheses with respect to developing postural synergies in typically and atypically developing persons.

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

    Science.gov (United States)

    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

  13. Coordination: Neural, Behavioral and Social Dynamics

    CERN Document Server

    Fuchs, Armin

    2008-01-01

    One of the most striking features of Coordination Dynamics is its interdisciplinary character. The problems we are trying to solve in this field range from behavioral phenomena of interlimb coordination and coordination between stimuli and movements (perception-action tasks) through neural activation patterns that can be observed during these tasks to clinical applications and social behavior. It is not surprising that close collaboration among scientists from different fields as psychology, kinesiology, neurology and even physics are imperative to deal with the enormous difficulties we are facing when we try to understand a system as complex as the human brain. The chapters in this volume are not simply write-ups of the lectures given by the experts at the meeting but are written in a way that they give sufficient introductory information to be comprehensible and useful for all interested scientists and students.

  14. [Risks of awkward posture].

    Science.gov (United States)

    Bazzini, G; Capodaglio, E; Panigazzi, M; Prestifilippo, E; Vercesi, C

    2010-01-01

    For posture we mean the position of the body in the space and the relationship with its segments. The correct posture is determined by neurophysiological, biomechanical, emotional, psychological and relation factors, enabling us to perform daily and working activities with the lowest energy expenditure. When possible we suggest during posture variation, a preventive measure where there are prolonged fixed activities.

  15. Effects of Levodopa on Postural Strategies in Parkinson’s disease

    OpenAIRE

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

    2016-01-01

    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.

  16. Improving Postural Control in the Battement Tendu: One Teacher's Reflections and Somatic Exercises

    Science.gov (United States)

    Batson, Glenna

    2010-01-01

    The battement tendu is introduced early in dance training, remaining integral to a dancer's vocabulary. Although appearing relatively simple to execute, the tendu aesthetic takes years to master. One reason might be that efficient performance requires complex coordination of postural balance. Known as postural control, this coordination appears in…

  17. Intra- and inter-subject variation in lower limb coordination during countermovement jumps in children and adults

    DEFF Research Database (Denmark)

    Raffalt, Peter C; Alkjær, Tine; Simonsen, Erik B

    2016-01-01

    The purpose of the present study was to investigate the coordination pattern and coordination variability (intra-subject and inter-subject) in children and adults during vertical countermovement jumps. Ten children (mean age: 11.5±1.8years) and ten adults (mean age: 26.1±4.9years) participated...... in the experiment. Lower body 3D-kinematics and kinetics from both legs were obtained during 9 vertical jumps of each subject. Coordination pattern and coordination variability of intra-limb and inter-limb coupling were established by modified vector coding and continuous relative phase. The adult group jumped...

  18. Redistribution of intra- and inter-limb support moments during downhill walking on different slopes.

    Science.gov (United States)

    Hong, Shih-Wun; Wang, Ting-Ming; Lu, Tung-Wu; Li, Jia-Da; Leu, Tsai-Hsueh; Ho, Wei-Pin

    2014-02-07

    Downhill walking presents a greater risk of falling as a result of slipping or loss of balance in comparison with level walking. The current study aimed to investigate the effects of inclination angles on the intra-limb (inter-joint) and inter-limb sharing of the body support during downhill walking for a better understanding of the associated control strategy. Fifteen young male adults (age: 32.6±5.2 years, height: 168.9±5.5cm, mass: 68.4±8.7kg) performed level and downhill walking while their kinematic and kinetic data were measured for calculating joint moments and total support moments of the lower limbs using inverse dynamics analysis. The peak total support moments of both the leading and trailing limbs increased with increasing inclination angles (p0.05), but the contributions of the hip increased with reduced contributions from the ankle (p0.05). During double-limb support, the main contributor to the whole body support changed from the trailing limb to the leading limb with increasing inclination angles (p<0.05). Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Effects of temporal and spatial cueing on anticipatory postural control in a rapid interceptive task.

    Science.gov (United States)

    Huntley, Andrew H; Zettel, John L

    2015-04-10

    Balance disruptions induced by voluntary focal arm actions are accommodated via anticipatory postural adjustments, but how this coordinated control is organized by the central nervous system remains unclear: either as combined or separate streams of postural-focal motor commands. For example, a focal arm task that dictates extremely tight temporal constraints may induce a focal response in absence of an anticipatory postural adjustment, providing evidence for separate focal-postural control streams. This study sought to probe the organization of focal-postural control via an interceptive task with very little available response time, and to determine whether focal-postural coordination depends on temporal and/or spatial foreknowledge of the task. Ten healthy young adults (5 males and 5 females; 20-29 years) reacted to catch a ball when standing under four conditions of temporal and spatial foreknowledge. Response onset was characterized by muscle activity from both postural and focal arm muscles. The catching task resulted in rapid muscle responses, but there was no difference between the fastest focal and postural muscle onsets. As expected, temporal cuing resulted in faster focal and postural onsets compared to spatial and control cuing trials. The accompaniment and time-locking of focal and postural muscle onsets, suggests that postural-focal coupling remains intact even under external time constraints and provides evidence for a single combined command stream of postural and focal control under such circumstances.

  20. The organization and control of intra-limb anticipatory postural adjustments and their role in movement performance

    Directory of Open Access Journals (Sweden)

    Paolo Cavallari

    2016-10-01

    Full Text Available Anticipatory Postural Adjustments (APAs are commonly described as unconscious muscular activities aimed to counterbalance the perturbation caused by the primary movement, so as to ensure the whole-body balance, as well as contributing to initiate the displacement of the body centre of mass when starting gait or whole-body reaching movements. These activities usually create one or more fixation chains which spread over several muscles of different limbs, and may be thus called inter-limb APAs. However, it has been reported that APAs also precede voluntary movements involving tiny masses, like a flexion/extension of the wrist or even a brisk flexion of the index-finger. In particular, such movements are preceded by an intra-limb APA chain, that involves muscles acting on the proximal joints. Considering the small mass of the moving segments, it is unlikely that the ensuing perturbation could threaten the whole body balance, so that it is interesting to enquire the physiological role of intra-limb APAs and their organization and control compared to inter-limb APAs.This review is focused on intra-limb APAs and highlights a strict correspondence in their behaviour and temporal/spatial organization with respect to inter-limb APAs. Hence it is suggested that both are manifestations of the same phenomenon. Particular emphasis is given to intra-limb APAs preceding index finger flexion, because their relatively simple biomechanics and the fact that muscular actions were limited to a single arm allowed peculiar investigations, leading to important conclusions. Indeed, such paradigm provided evidence that by granting a proper fixation of those body segments proximal to the moving one APAs are involved in refining movement precision, and also that APAs and prime mover activation are driven by a shared motor command.

  1. The Organization and Control of Intra-Limb Anticipatory Postural Adjustments and Their Role in Movement Performance.

    Science.gov (United States)

    Cavallari, Paolo; Bolzoni, Francesco; Bruttini, Carlo; Esposti, Roberto

    2016-01-01

    Anticipatory Postural Adjustments (APAs) are commonly described as unconscious muscular activities aimed to counterbalance the perturbation caused by the primary movement, so as to ensure the whole-body balance, as well as contributing to initiate the displacement of the body center of mass when starting gait or whole-body reaching movements. These activities usually create one or more fixation chains which spread over several muscles of different limbs, and may be thus called inter-limb APAs. However, it has been reported that APAs also precede voluntary movements involving tiny masses, like a flexion/extension of the wrist or even a brisk flexion of the index-finger. In particular, such movements are preceded by an intra-limb APA chain, that involves muscles acting on the proximal joints. Considering the small mass of the moving segments, it is unlikely that the ensuing perturbation could threaten the whole-body balance, so that it is interesting to enquire the physiological role of intra-limb APAs and their organization and control compared to inter-limb APAs. This review is focused on intra-limb APAs and highlights a strict correspondence in their behavior and temporal/spatial organization with respect to inter-limb APAs. Hence it is suggested that both are manifestations of the same phenomenon. Particular emphasis is given to intra-limb APAs preceding index-finger flexion, because their relatively simple biomechanics and the fact that muscular actions were limited to a single arm allowed peculiar investigations, leading to important conclusions. Indeed, such paradigm provided evidence that by granting a proper fixation of those body segments proximal to the moving one APAs are involved in refining movement precision, and also that APAs and prime mover activation are driven by a shared motor command.

  2. Neural mechanisms influencing interlimb coordination during locomotion in humans: presynaptic modulation of forearm H-reflexes during leg cycling.

    Science.gov (United States)

    Nakajima, Tsuyoshi; Mezzarane, Rinaldo A; Klarner, Taryn; Barss, Trevor S; Hundza, Sandra R; Komiyama, Tomoyoshi; Zehr, E Paul

    2013-01-01

    Presynaptic inhibition of transmission between Ia afferent terminals and alpha motoneurons (Ia PSI) is a major control mechanism associated with soleus H-reflex modulation during human locomotion. Rhythmic arm cycling suppresses soleus H-reflex amplitude by increasing segmental Ia PSI. There is a reciprocal organization in the human nervous system such that arm cycling modulates H-reflexes in leg muscles and leg cycling modulates H-reflexes in forearm muscles. However, comparatively little is known about mechanisms subserving the effects from leg to arm. Using a conditioning-test (C-T) stimulation paradigm, the purpose of this study was to test the hypothesis that changes in Ia PSI underlie the modulation of H-reflexes in forearm flexor muscles during leg cycling. Subjects performed leg cycling and static activation while H-reflexes were evoked in forearm flexor muscles. H-reflexes were conditioned with either electrical stimuli to the radial nerve (to increase Ia PSI; C-T interval  = 20 ms) or to the superficial radial (SR) nerve (to reduce Ia PSI; C-T interval  = 37-47 ms). While stationary, H-reflex amplitudes were significantly suppressed by radial nerve conditioning and facilitated by SR nerve conditioning. Leg cycling suppressed H-reflex amplitudes and the amount of this suppression was increased with radial nerve conditioning. SR conditioning stimulation removed the suppression of H-reflex amplitude resulting from leg cycling. Interestingly, these effects and interactions on H-reflex amplitudes were observed with subthreshold conditioning stimulus intensities (radial n., ∼0.6×MT; SR n., ∼ perceptual threshold) that did not have clear post synaptic effects. That is, did not evoke reflexes in the surface EMG of forearm flexor muscles. We conclude that the interaction between leg cycling and somatosensory conditioning of forearm H-reflex amplitudes is mediated by modulation of Ia PSI pathways. Overall our results support a conservation of neural control mechanisms between the arms and legs during locomotor behaviors in humans.

  3. Neural mechanisms influencing interlimb coordination during locomotion in humans: presynaptic modulation of forearm H-reflexes during leg cycling.

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Nakajima

    Full Text Available Presynaptic inhibition of transmission between Ia afferent terminals and alpha motoneurons (Ia PSI is a major control mechanism associated with soleus H-reflex modulation during human locomotion. Rhythmic arm cycling suppresses soleus H-reflex amplitude by increasing segmental Ia PSI. There is a reciprocal organization in the human nervous system such that arm cycling modulates H-reflexes in leg muscles and leg cycling modulates H-reflexes in forearm muscles. However, comparatively little is known about mechanisms subserving the effects from leg to arm. Using a conditioning-test (C-T stimulation paradigm, the purpose of this study was to test the hypothesis that changes in Ia PSI underlie the modulation of H-reflexes in forearm flexor muscles during leg cycling. Subjects performed leg cycling and static activation while H-reflexes were evoked in forearm flexor muscles. H-reflexes were conditioned with either electrical stimuli to the radial nerve (to increase Ia PSI; C-T interval  = 20 ms or to the superficial radial (SR nerve (to reduce Ia PSI; C-T interval  = 37-47 ms. While stationary, H-reflex amplitudes were significantly suppressed by radial nerve conditioning and facilitated by SR nerve conditioning. Leg cycling suppressed H-reflex amplitudes and the amount of this suppression was increased with radial nerve conditioning. SR conditioning stimulation removed the suppression of H-reflex amplitude resulting from leg cycling. Interestingly, these effects and interactions on H-reflex amplitudes were observed with subthreshold conditioning stimulus intensities (radial n., ∼0.6×MT; SR n., ∼ perceptual threshold that did not have clear post synaptic effects. That is, did not evoke reflexes in the surface EMG of forearm flexor muscles. We conclude that the interaction between leg cycling and somatosensory conditioning of forearm H-reflex amplitudes is mediated by modulation of Ia PSI pathways. Overall our results support a conservation of neural control mechanisms between the arms and legs during locomotor behaviors in humans.

  4. Effect of optimization postural training on the coordination compliance and postoperative complications risk in patients scheduled by thyroid surgery%优化体位训练对行择期甲状腺手术患者配合依从性及术后并发症发生风险的影响

    Institute of Scientific and Technical Information of China (English)

    邵敏; 段晓侠

    2016-01-01

    Objective:To investigate the effects of optimization postural training on the coordination compliance and postoperative complications risk in patients scheduled by thyroid surgery. Methods:Eighty patients scheduled by thyroid surgery were randomly divided into the control group and observation group(40 cases each group). The control group and observation group were treated with conventional postural training and optimization postural training, respectively. The coordination compliance, healthy knowledge, postoperative SF-36 score, postoperative complications and nursing satisfaction between two groups were compared. Results:The coordination compliance,healthy knowledge,postoperative SF-36 score and nursing satisfaction in observation group were higher than those in control group(P<0. 05 to P<0. 01). The incidences of the postoperative headache,nausea and vomiting and waist back pain in observation group were lower than those in control group(P<0. 05 to P<0. 01). Conclusions:The optimization postural training in nursing the patients scheduled by thyroid surgery can effectively improve the coordination compliance,healthy knowledge,quality of life and nurse-patient relationship, reduce the postoperative complications risk, and the clinical effects of which are better than those of conventional postural training.%目的::探讨优化体位训练对行择期甲状腺手术患者配合依从性及术后并发症发生风险的影响。方法:行择期甲状腺手术患者共80例,随机分为对照组和观察组,各40例,分别采用常规体位训练和优化体位训练。比较2组患者配合依从性、健康相关知识掌握率、术后SF-36评分、术后并发症发生率及护理满意度等。结果:观察组患者配合依从性、健康相关知识掌握率、SF-36评分及患者护理满意度均高于对照组(P<0.05~P<0.01);术后并发症头痛、恶心呕吐和腰背痛的发生率均低于对照组(P<0.05~P<0.01)。结论:优化体

  5. Interlimb relation during the double support phase of gait: an electromyographic, mechanical and energy-based analysis.

    Science.gov (United States)

    Sousa, Andreia S P; Silva, Augusta; Tavares, João Manuel R S

    2013-03-01

    The purpose of this study is to analyse the interlimb relation and the influence of mechanical energy on metabolic energy expenditure during gait. In total, 22 subjects were monitored as to electromyographic activity, ground reaction forces and VO2 consumption (metabolic power) during gait. The results demonstrate a moderate negative correlation between the activity of tibialis anterior, biceps femoris and vastus medialis of the trailing limb during the transition between mid-stance and double support and that of the leading limb during double support for the same muscles, and between these and gastrocnemius medialis and soleus of the trailing limb during double support. Trailing limb soleus during the transition between mid-stance and double support was positively correlated to leading limb tibialis anterior, vastus medialis and biceps femoris during double support. Also, the trailing limb centre of mass mechanical work was strongly influenced by the leading limbs, although only the mechanical power related to forward progression of both limbs was correlated to metabolic power. These findings demonstrate a consistent interlimb relation in terms of electromyographic activity and centre of mass mechanical work, being the relations occurred in the plane of forward progression the more important to gait energy expenditure.

  6. Classic ballet dancers postural patterns

    Directory of Open Access Journals (Sweden)

    Joseani Paulini Neves Simas

    2008-06-01

    Full Text Available The aim of this study was to evaluate classic ballet practice and its influence on postural patterns and (a identify the most frequent postural changes; (b determine the postural pattern; (c verify the existence of association of practice time and postural changes. The investigation was carried out in two stages: one, description in which 106 dancers participated; the other, causal comparative in which 50 dancers participated; and (a questionnaire; (b a checkerboard; (c postural chart; (d measure tape; (e camera and (f pedoscope were used as instrument. Descriptive and inferential statistics was used for analysis. The results revealed the most frequent postural changes such as hyperlordosis, unleveled shoulders and pronated ankles. Ballet seems to have negative implications in the postural development , affecting especially the vertebral spine, trunk and feet. The practice time was not a parameter to indicate the increase in postural changes. In conclusion, ballet may be associated with postural changes and determining a characteristic postural pattern.

  7. Developmental constraints of quadrupedal coordination across crawling styles in human infants.

    Science.gov (United States)

    Patrick, Susan K; Noah, J Adam; Yang, Jaynie F

    2012-06-01

    Human infants can crawl using several very different styles; this diversity appears at first glance to contradict our previous findings from hands-and-knees crawling, which suggested that there were strict limitations on coordination, imposed either mechanically or by the developing nervous system. To determine whether coordination was similarly restricted across crawling styles, we studied free crawling overground in 22 infants who used a number of different locomotor strategies. Despite the wide variety in the use of individual limbs and even the number of limbs used, the duration of the stance phase increased with duration of cycle, whereas the duration of the swing phase remained more constant. Additionally, all infants showed organized, rhythmic interlimb coordination. Alternating patterns (e.g., trotlike) predominated (86% of infants). Alternatively, yet much less frequently, all limbs used could work in synchrony (14% of infants). Pacelike patterns were never observed, even in infants that crawled with the belly remaining in contact with the ground so that stability was not a factor. To explore the robustness of the interlimb coordination, a perturbation that prolonged swing of the leg was imposed on 14 additional infants crawling on hands and knees overground or on the treadmill. The perturbation led to a resetting of the crawling pattern, but never to a change in the coordination of the limbs. The findings concur with those regarding other infant animals, together suggesting that the nervous system itself limits the coordination patterns available at a young age.

  8. Posture effects on spontaneous limb movements, alternated stepping, and the leg extension response in neonatal rats.

    Science.gov (United States)

    Mendez-Gallardo, Valerie; Roberto, Megan E; Kauer, Sierra D; Brumley, Michele R

    2016-03-01

    The development of postural control is considered an important factor for the expression of coordinated behavior such as locomotion. In the natural setting of the nest, newborn rat pups adapt their posture to perform behaviors of ecological relevance such as those related to suckling. The current study explores the role of posture in the expression of three behaviors in the newborn rat: spontaneous limb activity, locomotor-like stepping behavior, and the leg extension response (LER). One-day-old rat pups were tested in one of two postures--prone or supine--on each of these behavioral measures. Results showed that pups expressed more spontaneous activity while supine, more stepping while prone, and no differences in LER expression between the two postures. Together these findings show that posture affects the expression of newborn behavior patterns in different ways, and suggest that posture may act as a facilitator or a limiting factor in the expression of different behaviors during early development.

  9. Exercise and Posture

    Science.gov (United States)

    ... Have Spondylitis? Treatment Information Medications Exercise & Posture Diet & Nutrition Medication & Diet Dietary Supplements Changing Your Diet The London AS / Low Starch Diet Complementary Treatments Possible Complications Iritis or Anterior Uveitis Fatigue in Spondylitis Pain in ...

  10. Functional synergies underlying control of upright posture during changes in head orientation.

    Directory of Open Access Journals (Sweden)

    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

  11. Postural perturbations: new insights for treatment of balance disorders

    Science.gov (United States)

    Horak, F. B.; Henry, S. M.; Shumway-Cook, A.; Peterson, B. W. (Principal Investigator)

    1997-01-01

    This article reviews the neural control of posture as understood through studies of automatic responses to mechanical perturbations. Recent studies of responses to postural perturbations have provided a new view of how postural stability is controlled, and this view has profound implications for physical therapy practice. We discuss the implications for rehabilitation of balance disorders and demonstrate how an understanding of the specific systems underlying postural control can help to focus and enrich our therapeutic approaches. By understanding the basic systems underlying control of balance, such as strategy selection, rapid latencies, coordinated temporal spatial patterns, force control, and context-specific adaptations, therapists can focus their treatment on each patient's specific impairments. Research on postural responses to surface translations has shown that balance is not based on a fixed set of equilibrium reflexes but on a flexible, functional motor skill that can adapt with training and experience. More research is needed to determine the extent to which quantification of automatic postural responses has practical implications for predicting falls in patients with constraints in their postural control system.

  12. Postural perturbations: new insights for treatment of balance disorders

    Science.gov (United States)

    Horak, F. B.; Henry, S. M.; Shumway-Cook, A.; Peterson, B. W. (Principal Investigator)

    1997-01-01

    This article reviews the neural control of posture as understood through studies of automatic responses to mechanical perturbations. Recent studies of responses to postural perturbations have provided a new view of how postural stability is controlled, and this view has profound implications for physical therapy practice. We discuss the implications for rehabilitation of balance disorders and demonstrate how an understanding of the specific systems underlying postural control can help to focus and enrich our therapeutic approaches. By understanding the basic systems underlying control of balance, such as strategy selection, rapid latencies, coordinated temporal spatial patterns, force control, and context-specific adaptations, therapists can focus their treatment on each patient's specific impairments. Research on postural responses to surface translations has shown that balance is not based on a fixed set of equilibrium reflexes but on a flexible, functional motor skill that can adapt with training and experience. More research is needed to determine the extent to which quantification of automatic postural responses has practical implications for predicting falls in patients with constraints in their postural control system.

  13. Autoimmune Basis for Postural Tachycardia Syndrome

    Science.gov (United States)

    2016-10-14

    Postural Orthostatic Tachycardia Syndrome; Postural Tachycardia Syndrome; Tachycardia; Arrhythmias, Cardiac; Autonomic Nervous System Diseases; Orthostatic Intolerance; Cardiovascular Diseases; Primary Dysautonomias

  14. Can quiet standing posture predict compensatory postural adjustment?

    Directory of Open Access Journals (Sweden)

    Gabriel Bueno Lahóz Moya

    2009-01-01

    Full Text Available OBJECTIVE: The aim of this study was to analyze whether quiet standing posture is related to compensatory postural adjustment. INTRODUCTION: The latest data in clinical practice suggests that static posture may play a significant role in musculoskeletal function, even in dynamic activities. However, no evidence exists regarding whether static posture during quiet standing is related to postural adjustment. METHODS: Twenty healthy participants standing on a movable surface underwent unexpected, standardized backward and forward postural perturbations while kinematic data were acquired; ankle, knee, pelvis and trunk positions were then calculated. An initial and a final video frame representing quiet standing posture and the end of the postural perturbation were selected in such a way that postural adjustments had occurred between these frames. The positions of the body segments were calculated in these initial and final frames, together with the displacement of body segments during postural adjustments between the initial and final frames. The relationship between the positions of body segments in the initial and final frames and their displacements over this time period was analyzed using multiple regressions with a significance level of p < 0.05. RESULTS: We failed to identify a relationship between the position of the body segments in the initial and final frames and the associated displacement of the body segments. DISCUSSION: The motion pattern during compensatory postural adjustment is not related to quiet standing posture or to the final posture of compensatory postural adjustment. This fact should be considered when treating balance disturbances and musculoskeletal abnormalities. CONCLUSION: Static posture cannot predict how body segments will behave during compensatory postural adjustment.

  15. Effects of aging on interjoint coordination during arm reaching

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius da Silva

    Full Text Available Abstract Introduction Moving the arm towards an object is a complex task. Movements of the arm joints must be well coordinated in order to obtain a smooth and accurate hand trajectory. Most studies regarding reaching movements address young subjects. Coordination differences in the neural mechanism underlying motor control throughout the life stages is yet unknown. The understanding of these changes can lead to a better comprehension of neuromotor pathologies and therefore to more suitable therapies. Methods Our purpose was to investigate interjoint coordination in three different aging groups (children, young, elderly. Kinematics and kinetics specific variables were analyzed focusing on defined parameters to get insight into arm coordination. Intersegmental dynamics was used to calculate shoulder and elbow torques assuming a 2-link segment model of the upper extremity (upper arm and forearm with two friction-less joints (shoulder and elbow. A virtual reality environment was used to examine multidirectional planar reaching in three different directions (randomly presented. Results Seven measures were computed to investigate group interlimb differences: shoulder and elbow muscle torques (peak and impulse, work performed by shoulder and elbow joints, maximum velocity, movement distance, distance error at final position, movement duration and acceleration duration. Our data analysis showed differences between movement performances for all analyzed variables, at all ages. Conclusion We found that the intersegmental dynamics for the interlimb (left/right comparisons were similar for the elderly and children groups as compared to the young. In addition, the coordination and control of motor tasks changes during life, becoming less effective in old age.

  16. Postural deformities in Parkinson's disease

    NARCIS (Netherlands)

    Doherty, K.M.; Warrenburg, B.P.C. van de; Peralta, M.C.; Silveira-Moriyama, L.; Azulay, J.P.; Gershanik, O.S.; Bloem, B.R.

    2011-01-01

    Postural deformities are frequent and disabling complications of Parkinson's disease (PD) and atypical parkinsonism. These deformities include camptocormia, antecollis, Pisa syndrome, and scoliosis. Recognition of specific postural syndromes might have differential diagnostic value in patients prese

  17. Amplification of interlimb reflexes evoked by stimulating the hand simultaneously with conditioning from the foot during locomotion.

    Science.gov (United States)

    Nakajima, Tsuyoshi; Barss, Trevor; Klarner, Taryn; Komiyama, Tomoyoshi; Zehr, E Paul

    2013-03-13

    Widespread interlimb reflexes evoked in leg muscles by cutaneous stimulation of the hand are phase-modulated and behaviorally relevant to produce functional changes in ankle trajectory during walking. These reflexes are complementary to the segmental responses evoked by stimulation at the ankle. Despite differences in the expression of reflex amplitude based upon site of nerve stimulation, there are some common features as well, suggesting the possibility of shared interneuronal pathways. Currently little is known about integration or shared reflex systems from interlimb cutaneous networks during human locomotion. Here we investigated convergent reflex effects following cutaneous stimulation of the hand and foot during arm and leg cycling (AL) by using spatial facilitation. Participants performed AL cycling and static activation of the target muscle knee extensor vastus lateralis (VL) in 3 different randomly ordered nerve stimulation conditions: 1) superficial radial nerve (SR; input from hand); 2) superficial peroneal nerve (SP; input from foot); and, 3) combined stimulation (SR + SP). Stimuli were applied around the onset of rhythmic EMG bursts in VL corresponding to the onset of the power or leg extension phase. During AL cycling, small inhibitory (~80 ms) and large facilitatory reflexes (~100 ~ 150 ms) were seen in VL. The amplitudes of the facilitatory responses with SR + SP stimulation were significantly larger than those for SP or SR stimulation alone. The facilitation was also significantly larger than the simple mathematical summation of amplitudes from SP and SR trials. This indicates extra facilitation beyond what would be accounted for by serial neuronal processing and was not observed during static activation. We conclude that AL cycling activates shared interneurons in convergent reflex pathways from cutaneous inputs innervating the hand and leg. This enhanced activity has functional implications for corrective responses during locomotion and for

  18. Self-sustained motor activity triggered by interlimb reflexes in chronic spinal cord injury, evidence of functional ascending propriospinal pathways.

    Directory of Open Access Journals (Sweden)

    Penelope A McNulty

    Full Text Available The loss or reduction of supraspinal inputs after spinal cord injury provides a unique opportunity to examine the plasticity of neural pathways within the spinal cord. In a series of nine experiments on a patient, quadriplegic due to spinal cord injury, we investigated interlimb reflexes and self-sustained activity in completely paralyzed and paretic muscles due to a disinhibited propriospinal pathway. Electrical stimuli were delivered over the left common peroneal nerve at the fibular head as single stimuli or in trains at 2-100 Hz lasting 1 s. Single stimuli produced a robust interlimb reflex twitch in the contralateral thumb at a mean latency 69 ms, but no activity in other muscles. With stimulus trains the thumb twitch occurred at variable subharmonics of the stimulus rate, and strong self-sustained activity developed in the contralateral wrist extensors, outlasting both the stimuli and the thumb reflex by up to 20 s. Similar behavior was recorded in the ipsilateral wrist extensors and quadriceps femoris of both legs, but not in the contralateral thenar or peroneal muscles. The patient could not terminate the self-sustained activity voluntarily, but it was abolished on the left by attempted contractions of the paralyzed thumb muscles of the right hand. These responses depend on the functional integrity of an ascending propriospinal pathway, and highlight the plasticity of spinal circuitry following spinal cord injury. They emphasize the potential for pathways below the level of injury to generate movement, and the role of self-sustained reflex activity in the sequelae of spinal cord injury.

  19. 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....

  20. The relationship between a child's postural stability and manual dexterity.

    Science.gov (United States)

    Flatters, Ian; Mushtaq, Faisal; Hill, Liam J B; Holt, Raymond J; Wilkie, Richard M; Mon-Williams, Mark

    2014-09-01

    The neural systems responsible for postural control are separate from the neural substrates that underpin control of the hand. Nonetheless, postural control and eye-hand coordination are linked functionally. For example, a stable platform is required for precise manual control tasks (e.g. handwriting) and thus such skills often cannot develop until the child is able to sit or stand upright. This raises the question of the strength of the empirical relationship between measures of postural stability and manual motor control. We recorded objective computerised measures of postural stability in stance and manual control in sitting in a sample of school children (n = 278) aged 3-11 years in order to explore the extent to which measures of manual skill could be predicted by measures of postural stability. A strong correlation was found across the whole sample between separate measures of postural stability and manual control taken on different days. Following correction for age, a significant but modest correlation was found. Regression analysis with age correction revealed that postural stability accounted for between 1 and 10% of the variance in manual performance, dependent on the specific manual task. These data reflect an interdependent functional relationship between manual control and postural stability development. Nevertheless, the relatively small proportion of the explained variance is consistent with the anatomically distinct neural architecture that exists for 'gross' and 'fine' motor control. These data justify the approach of motor batteries that provide separate assessments of postural stability and manual dexterity and have implications for therapeutic intervention in developmental disorders.

  1. Working postures: prediction and evaluation

    NARCIS (Netherlands)

    Delleman, N.J.

    1999-01-01

    To date, workstation designers cannot see the effects of a design on working posture before a mock-up/prototype is available. At that moment, usually the margin for creating the conditions required for adopting favourable working postures is still very limited. Posture prediction at an early design

  2. 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

  3. Active control of bias for the control of posture and movement.

    Science.gov (United States)

    Guigon, Emmanuel

    2010-08-01

    Posture and movement are fundamental, intermixed components of motor coordination. Current approaches consider either that 1) movement is an active, anticipatory process and posture is a passive feedback process or 2) movement and posture result from a common passive process. In both cases, the presence of a passive component renders control scarcely robust and stable in the face of transmission delays and low feedback gains. Here we show in a model that posture and movement could result from the same active process: an optimal feedback control that drives the body from its estimated state to its goal in a given (planning) time by acting through muscles on the insertion position (bias) of compliant linkages (tendons). Computer simulations show that iteration of this process in the presence of noise indifferently produces realistic postural sway, fast goal-directed movements, and natural transitions between posture and movement.

  4. Postural orthostatic tachycardia syndrome.

    Science.gov (United States)

    Agarwal, A K; Garg, R; Ritch, A; Sarkar, P

    2007-07-01

    Postural orthostatic tachycardia syndrome (POTS) is an autonomic disturbance which has become better understood in recent years. It is now thought to encompass a group of disorders that have similar clinical features, such as orthostatic intolerance, but individual distinguishing parameters--for example, blood pressure and pulse rate. The clinical picture, diagnosis, and management of POTS are discussed.

  5. Sensory Contributions to Balance in Boys with Developmental Coordination Disorder

    Science.gov (United States)

    Deconinck, Frederik J. A.; De Clercq, Dirk; Van Coster, Rudy; Oostra, Ann; Dewitte, Griet; Savelsbergh, Geert J. P.; Cambier, Dirk; Lenoir, Matthieu

    2008-01-01

    This study examined and compared the control of posture during bilateral stance in ten boys with Developmental Coordination Disorder (DCD) of 6-8 years old and ten matched typically developing boys in four sensory conditions (with or without vision, on a firm or complaint surface). In all conditions mean postural sway velocity was larger for the…

  6. Effects of Computer-Aided Interlimb Force Coupling Training on Paretic Hand and Arm Motor Control following Chronic Stroke: A Randomized Controlled Trial.

    Science.gov (United States)

    Lin, Chueh-Ho; Chou, Li-Wei; Luo, Hong-Ji; Tsai, Po-Yi; Lieu, Fu-Kong; Chiang, Shang-Lin; Sung, Wen-Hsu

    2015-01-01

    We investigated the training effects of interlimb force coupling training on paretic upper extremity outcomes in patients with chronic stroke and analyzed the relationship between motor recovery of the paretic hand, arm and functional performances on paretic upper limb. A randomized controlled trial with outcome assessment at baseline and after 4 weeks of intervention. Taipei Veterans General Hospital, National Yang-Ming University. Thirty-three subjects with chronic stroke were recruited and randomly assigned to training (n = 16) and control groups (n = 17). The computer-aided interlimb force coupling training task with visual feedback included different grip force generation methods on both hands. The Barthel Index (BI), the upper extremity motor control Fugl-Meyer Assessment (FMA-UE), the Motor Assessment Score (MAS), and the Wolf Motor Function Test (WMFT). All assessments were executed by a blinded evaluator, and data management and statistical analysis were also conducted by a blinded researcher. The training group demonstrated greater improvement on the FMA-UE (pcontrol group after 4 weeks of intervention. In addition, a moderate correlation was found between the improvement of scores for hand scales of the FMA and other portions of the FMA UE (r = .528, p = .018) or MAS (r = .596, p = .015) in the training group. Computer-aided interlimb force coupling training improves the motor recovery of a paretic hand, and facilitates motor control and enhances functional performance in the paretic upper extremity of people with chronic stroke. ClinicalTrials.gov NCT02247674.

  7. 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.

  8. 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, ppostural 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 conditions, which was independent of clinical characteristics. Patients further demonstrated similar pattern and level of utilizing sensory information to maintain balance compared to the controls.

  9. Preliminary analysis of non-dominant proprioceptive acuity and interlimb asymmetry in the human wrist.

    Science.gov (United States)

    Contu, Sara; Cappello, Leonardo; Konczak, Jurgen; Masia, Lorenzo

    2015-08-01

    Proprioception provides information about limb configuration which are essential for planning and controlling its posture and movement. Asymmetries in the way dominant and non-dominant limbs exploit proprioceptive information have been previously evaluated, with contradictory results due to the difference in the employed methodology. A measure of proprioceptive acuity that does not reflect the influence of one limb on the other consists in the evaluation of the psychophysical threshold. This metric, evaluated separately for each limb and involving only passive movements, reflects a reliable measure of proprioceptive acuity. The aim of this work is to first evaluate the proprioceptive acuity of the non-dominant wrist joint in flexion/extension and adduction/abduction and to compare these results to the acuity of the dominant wrist. Data were collected during a unidirectional 2-alternative-forcedchoice test performed by six right-handed subjects. We found acuity of 1.31°, 1.26°, 1.33° and 1.63° respectively for abduction, adduction, extension and flexion of the non-dominant wrist. Acuity of the dominant wrist was assessed for five of the subjects for abduction and flexion and resulted lower (mean values were respectively 1.64° and 2.14°). The preliminary results suggest a leading role of the non-dominant wrist in the processing of the proprioceptive feedback.

  10. Investigation of a passive inter-limb device on step-to-step transition of human walking.

    Science.gov (United States)

    Zhang, Jun-tian; Li, Qingguo

    2013-06-01

    In walking like an inverted pendulum, the step-to-step transition period requires a substantial amount of simultaneous positive and negative mechanical work to redirect the center of mass between steps and it was considered as a major determinant of gait in terms of metabolic expenditure. In the current study, we developed a passive inter-limb device that transfers energy between the legs during the step-to-step transition period. By effectively transferring the energy dissipated at heel-strike from the leading leg to the trailing leg which is performing push-off, we hypothesize that the mechanical cost of transport (COT) will be reduced. Consequently, the lower limb muscles are required to do less positive and negative work, resulting in a reduced metabolic COT. Data from five subjects walking at 1.2m/s on an instrumented treadmill with the device active and passive was collected. It was found that the mechanical COT during the step-to-step transition period was reduced when walking with the device active. However, contrary to our hypothesis the metabolic COT increased when walking with the device active.

  11. Spinal and supraspinal postural networks.

    Science.gov (United States)

    Deliagina, T G; Beloozerova, I N; Zelenin, P V; Orlovsky, G N

    2008-01-01

    Different species maintain a particular body orientation in space (upright in humans, dorsal-side-up in quadrupeds, fish and lamprey) due to the activity of a closed-loop postural control system. We will discuss operation of spinal and supraspinal postural networks studied in a lower vertebrate (lamprey) and in two mammals (rabbit and cat). In the lamprey, the postural control system is driven by vestibular input. The key role in the postural network belongs to the reticulospinal (RS) neurons. Due to vestibular input, deviation from the stabilized body orientation in any (roll, pitch, yaw) plane leads to generation of RS commands, which are sent to the spinal cord and cause postural correction. For each of the planes, there are two groups of RS neurons responding to rotation in the opposite directions; they cause a turn opposite to the initial one. The command transmitted by an individual RS neuron causes the motor response, which contributes to the correction of posture. In each plane, the postural system stabilizes the orientation at which the antagonistic vestibular reflexes compensate for each other. Thus, in lamprey the supraspinal networks play a crucial role in stabilization of body orientation, and the function of the spinal networks is transformation of supraspinal commands into the motor pattern of postural corrections. In terrestrial quadrupeds, the postural system stabilizing the trunk orientation in the transversal plane was analyzed. It consists of two relatively independent sub-systems stabilizing orientation of the anterior and posterior parts of the trunk. They are driven by somatosensory input from limb mechanoreceptors. Each sub-system consists of two closed-loop mechanisms - spinal and spino-supraspinal. Operation of the supraspinal networks was studied by recording the posture-related activity of corticospinal neurons. The postural capacity of spinal networks was evaluated in animals with lesions to the spinal cord. Relative contribution of

  12. 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.

  13. Cinerama sickness and postural instability

    NARCIS (Netherlands)

    Bos, J.E.; Ledegang, W.D.; Lubeck, A.J.A.; Stins, J.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 af

  14. Immediate Effects of Acupuncture Treatment on Intra- and Inter-Limb Contributions to Body Support During Gait in Patients with Bilateral Medial Knee Osteoarthritis.

    Science.gov (United States)

    Liu, Yen-Hung; Wei, I-Pin; Wang, Ting-Ming; Lu, Tung-Wu; Lin, Jaung-Geng

    2017-01-01

    Knee osteoarthritis (OA) often leads to altered balance control, joint motion and loading patterns during gait. Acupuncture has been proven to be effective in pain relief but its effects on inter-joint load-sharing for body balance have not been reported. The current study bridged the gap by quantifying the immediate effects of acupuncture on the inter-joint and inter-limb load-sharing in patients with knee OA during level walking in terms of the total support moment (Ms) and the contribution of individual joints to the total support moment. Gait analysis was performed on fifteen healthy controls and on fifteen patients with mild to moderate bilateral medial knee OA. After acupuncture treatment the patients with bilateral knee OA walked with significantly increased speed ([Formula: see text]), and were able to resist greater and closer-to-normal knee flexion moments ([Formula: see text]). They also changed the inter-joint sharing of the support moments with increased knee ([Formula: see text]) contributions, but reduced hip contributions ([Formula: see text]) to the sagittal Ms during single-limb support. They showed an asymmetric inter-limb load-sharing similar to the normal controls, with increased sharing of the time integral of both the sagittal and frontal whole body support moment by the leading limb during double-limb support ([Formula: see text]). The altered intra- and inter-limb contributions to the demand of supporting the body during gait suggests that acupuncture treatment led to immediate changes in the control strategy toward a normal pattern. However, the effects of these changes on the progression of the disease in the long term would require further investigation.

  15. The relationship between intermittent limit cycles and postural instability associated with Parkinson’s disease

    Institute of Scientific and Technical Information of China (English)

    James R. Chagdes; Jessica E. Huber; Meredith Saletta; Meghan Darling-White; Arvind Raman; Shirley Rietdyk; Howard N. Zelaznik; Jeffrey M. Haddad

    2016-01-01

    Background: Many disease-specific factors such as muscular weakness, increased muscle stiffness, varying postural strategies, and changes in postural reflexes have been shown to lead to postural instability and fall risk in people with Parkinson’s disease (PD). Recently, analytical techniques, inspired by the dynamical systems perspective on movement control and coordination, have been used to examine the mechanisms underlying the dynamics of postural declines and the emergence of postural instabilities in people with PD. Methods: A wavelet-based technique was used to identify limit cycle oscillations (LCOs) in the anterior–posterior (AP) postural sway of people with mild PD (n=10) compared to age-matched controls (n=10). Participants stood on a foam and on a rigid surface while completing a dual task (speaking). Results: There was no significant difference in the root mean square of center of pressure between groups. Three out of 10 participants with PD demonstrated LCOs on the foam surface, while none in the control group demonstrated LCOs. An inverted pendulum model of bipedal stance was used to demonstrate that LCOs occur due to disease-specific changes associated with PD:time-delay and neuromuscular feedback gain. Conclusion: Overall, the LCO analysis and mathematical model appear to capture the subtle postural instabilities associated with mild PD. In addition, these findings provide insights into the mechanisms that lead to the emergence of unstable posture in patients with PD.

  16. The influence of body posture on the kinematics of prehension in humans and gorillas (Gorilla gorilla).

    Science.gov (United States)

    Reghem, E; Chèze, L; Coppens, Y; Pouydebat, E

    2014-03-01

    Much of our current understanding of human prehension in a comparative context is based on macaque models in a sitting, constrained body posture. In a previous study, we clearly showed differences in the amplitude of the forelimb joints between five primate species (lemur, capuchin, chimpanzee, gorilla and human) during unconstrained grasping where the animals were free to choose their body posture. One of our interrogations was to know if these differences could be due to the body posture. To address this question, this study compares humans with new data for gorillas during an unconstrained food prehension task in two body postures, a sitting and a quadrupedal one. The objective is to determine the behavioral and kinematic strategies (amplitudes and patterns of evolution of the articular angles) as well as differences and invariants of trunk and forelimb motions between species. The subjects were recorded by five cameras, and landmarks were digitized frame by frame to reconstruct 3D movement. Our results show that (1) despite significant influences of body postures on ranges of motion in gorillas and humans, species preserve their specific forelimb joint and trunk contribution; (2) body posture has a limited effect on the basic pattern of wrist velocity. Our study indicates that different primate species have specific kinematic features of limb coordination during prehension, which dose not alter with changes in posture. Therefore, across varying species, it is possible to compare limb kinematics irrespective of postural constraints and unconstrained condition need to be explored in other primates to understand the evolution of primate prehension.

  17. POSTUR PADA WANITA HAMIL

    Directory of Open Access Journals (Sweden)

    Paryono .

    2013-09-01

    Full Text Available ABSTRACTIntroduction: Pregnancy effects in changes on all body systems leading to a new balance women and maternal adaptation.Weight gain in pregnant women from both the uterus and breast development generally occurs at the front of the body, butwhen standing they were still able to maintain a posture that does not face. The purpose of this article is to examine thereasons why pregnant women do not fall to front and how the good attitude of the pregnant woman's body.Materials and Methods: Material of this article are literatures related to pregnancy and the pregnant woman's bodyp o s t u r e , a n d t h e y w e r e c o l l e c t e d b y l i t e r a t u r e ' s s t u d y a n d l i t e r a r y s t u d y .Discussion: Increased abdominal distension that makes tilting the pelvis forward, decreased abdominal muscle tone andincrease weight gain in late pregnancy requires a readjustment spinal curvature. Woman's center of gravity shifts forward.Lumbosakrum normal curve should be more curved and the curvature of the servikodorsal be formed to maintain balance.Assessment of anterior view, lateral and posterior body should include an understanding of the physical structures such asjoints and muscles as well as how the meridian pathways. To compensate for the anterior position of the enlarged uterus,lordosis shifting center of gravity to the back of the lower limbs. There is an increased sacroiliac joint mobility,sakrokoksigeal, and pubic joints during pregnancy, possibly due to hormonal changes. Individual assessments will berequired to determine the pattern of muscle for every person, especially for those who have musculoskeletal problems.Conclusions and Recommendations: The size of the stomach in a pregnant woman, then the gravity of the body changes.Body to be biased toward the rear, but this position makes your back hurt. Advice for pregnant women in order to maintainyour posture as follows: head upKeyword : Posture, Pregnancy, Women.

  18. Kinesio Taping effect on postural balance in the elderly

    OpenAIRE

    2014-01-01

    The aging process leads to balance disorders that can increase the number of falls. The Kinesio Taping is a method that aims at improving muscle performance, proprioception, coordination and balance. The aim of the study was to investigate the Kinesio Taping effects on postural balance in the elderly population. We evaluated 62 female seniors, with an average age of 68±5 years, who were divided into two groups: the Kinesio Taping group, in which the elderly women (n=31) were submitted to...

  19. Stabilizing posture through imagery.

    Science.gov (United States)

    Papalia, Eleonora; Manzoni, Diego; Santarcangelo, Enrica L

    2014-01-01

    Abstract In the general population, suppression of vision modulates body sway by increasing the center of pressure (CoP) velocity, while a light fingertip touch reduces the area of the CoP displacement in blindfolded subjects. This study assessed whether imagined fixation and fingertip touch differentially stabilize posture in subjects with high (highs) and low (lows) hypnotizability. Visual and tactile imageries were ineffective in lows. In highs, the effects of visual imagery could not be evaluated because the real information was ineffective; real tactile stimulation was effective only on velocity, but the imagery effects could not be definitely assessed owing to low effect size. The highs' larger variability could account for this and represents the most important finding.

  20. The effect of asymmetry of posture on anticipatory postural adjustments.

    Science.gov (United States)

    Aruin, Alexander S

    2006-06-19

    The study investigates the effect of body asymmetry on anticipatory postural adjustments (APAs). Subjects performed a task involving a standard load release induced by a shoulder abduction movement while standing symmetrically or in an asymmetrical stance with either their right or left leg in 45 degrees of external rotation. EMG activities of trunk and leg muscles were recorded during the postural perturbation and were quantified within the time intervals typical of APAs. Anticipatory postural adjustments were observed in all experimental conditions. It was found that asymmetrical body positioning was associated with significant asymmetrical patterns of APAs seen in the right and left distal muscles. These APA asymmetries were dependant upon the side in which the body asymmetry was induced: reduced APAs were observed in the leg muscles on the side of leg rotation, while increased APAs were seen in the muscles on the contralateral side. These findings stress the important role that body asymmetries play in the control of upright posture.

  1. Reliability of upright posture measurements in primary school children

    Directory of Open Access Journals (Sweden)

    Grimmer Karen

    2005-06-01

    Full Text Available Abstract Background Correct upright posture is considered to be a measure of good musculoskeletal health. Little is known about the usual variability of children's upright standing posture. The aim of this study was to assess differences between repeated measures of upright posture in a group of primary school children. Methods Sagittal plane photographs of usual, relaxed upright standing posture of 38 boys and girls aged 5–12 years were taken twice within an hour. Reflective markers were placed over the canthus, tragus, C7 spinous process, greater trochanter and lateral malleolus. Digitising software was used to calculate the x,y plane coordinates, from which five postural angles were calculated (trunk, neck, gaze, head on neck, lower limb. Height, weight, motor control estimates (as measured by the Brace Tests and presence of recent pain were recorded for each child, and the association between the first test measure of posture angles and these factors was assessed using linear regression and ANOVA models. Multiple ANOVA models were applied to analyse the effect of repeated testing, and significant predictors on the angles. Results Four of the five postural angles (trunk, neck, head on neck, lower limb were significantly influenced by age. As age was strongly associated with height (r2 = 0.84 and moderately associated with weight and motor control (r2 = 0.67, 0.56 respectively, these developmental parameters may well explain the age effect on angles. There was no relationship between age and pain reported on either the testing day, or recently, and there was no gender influence on any angle. There was no significant effect of repeated testing on any angle (ICC>0.93. None of the hypothesized predictors were associated with differences in angles from repeated testing. Conclusion This study outlined the variability of relaxed upright standing posture of children aged 5–12 years, when measured twice in an hour. Age influenced the size of the

  2. Body posture and postural stability of people practicing qigong

    Directory of Open Access Journals (Sweden)

    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.

  3. The organization of anticipatory postural adjustments

    OpenAIRE

    Aruin Alexander S.

    2002-01-01

    Central control of posture is expressed through anticipatory and compensatory postural adjustments. Anticipatory postural adjustments (APAs) precede planned postural perturbations and minimize them with anticipatory corrections, while compensatory postural adjustments deal with actual perturbations of balance that occur as a result of suboptimal efficiency of anticipatory corrections. The process of generation of APAs is affected by three major factors: expected magnitude and direction of the...

  4. Development of Postural Control in Healthy Children: A Functional Approach

    Directory of Open Access Journals (Sweden)

    Christine Assaiante

    2005-01-01

    Full Text Available From a set of experimental studies showing how intersegmental coordination develops during childhood in various posturokinetic tasks, we have established a repertoire of equilibrium strategies in the course of ontogenesis. The experimental data demonstrate that the first reference frame used for the organization of balance control during locomotion is the pelvis, especially in young children. Head stabilization during posturokinetic activities, particularly locomotion, constitutes a complex motor skill requiring a long time to develop during childhood. When studying the emergence of postural strategies, it is essential to distinguish between results that can be explained by biomechanical reasons strictly and those reflecting the maturation of the central nervous system (CNS. To address this problem, we have studied our young subjects in situations requiring various types of adaptation. The studies dealing with adaptation of postural strategies aimed at testing short and long-term adaptation capacity of the CNS during imposed transient external biomechanical constraints in healthy children, and during chronic internal constraints in children with skeletal pathologies. In addition to maintenance of balance, another function of posture is to ensure the orientation of a body segment. It appears that the control of orientation and the control of balance both require the trunk as an initial reference frame involving a development from egocentric to exocentric postural control. It is concluded that the first step for children consists in building a repertoire of postural strategies, and the second step consists in learning to select the most appropriate postural strategy, depending on the ability to anticipate the consequence of the movement in order to maintain balance control and the efficiency of the task.

  5. Imaging Posture Veils Neural Signals

    Science.gov (United States)

    Thibault, Robert T.; Raz, Amir

    2016-01-01

    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.

  6. 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.

  7. Anticipatory postural adjustments and anticipatory synergy adjustments: preparing to a postural perturbation with predictable and unpredictable direction.

    Science.gov (United States)

    Piscitelli, Daniele; Falaki, Ali; Solnik, Stanislaw; Latash, Mark L

    2017-03-01

    We explored two aspects of feed-forward postural control, anticipatory postural adjustments (APAs) and anticipatory synergy adjustments (ASAs) seen prior to self-triggered unloading with known and unknown direction of the perturbation. In particular, we tested two main hypotheses predicting contrasting changes in APAs and ASAs. The first hypothesis predicted no major changes in ASAs. The second hypothesis predicted delayed APAs with predominance of co-contraction patterns when perturbation direction was unknown. Healthy subjects stood on the force plate and held a bar with two loads acting in the forward and backward directions. They pressed a trigger that released one of the loads causing a postural perturbation. In different series, the direction of the perturbation was either known (the same load released in all trials) or unknown (the subjects did not know which of the two loads would be released). Surface electromyograms were recorded and used to quantify APAs, synergies stabilizing center of pressure coordinate (within the uncontrolled manifold hypothesis), and ASA. APAs and ASAs were seen in all conditions. APAs were delayed, and predominance of co-contraction patterns was seen under the conditions with unpredictable direction of perturbation. In contrast, no significant changes in synergies and ASAs were seen. Overall, these results show that feed-forward control of vertical posture has two distinct components, reflected in APAs and ASAs, which show qualitatively different adjustments with changes in predictability of the direction of perturbation. These results are interpreted within the recently proposed hierarchical scheme of the synergic control of motor tasks. The observations underscore the complexity of the feed-forward postural control, which involves separate changes in salient performance variables (such as coordinate of the center of pressure) and in their stability properties.

  8. Movement Induces the Use of External Spatial Coordinates for Tactile Localization in Congenitally Blind Humans.

    Science.gov (United States)

    Heed, Tobias; Möller, Johanna; Röder, Brigitte

    2015-01-01

    To localize touch, the brain integrates spatial information coded in anatomically based and external spatial reference frames. Sighted humans, by default, use both reference frames in tactile localization. In contrast, congenitally blind individuals have been reported to rely exclusively on anatomical coordinates, suggesting a crucial role of the visual system for tactile spatial processing. We tested whether the use of external spatial information in touch can, alternatively, be induced by a movement context. Sighted and congenitally blind humans performed a tactile temporal order judgment task that indexes the use of external coordinates for tactile localization, while they executed bimanual arm movements with uncrossed and crossed start and end postures. In the sighted, start posture and planned end posture of the arm movement modulated tactile localization for stimuli presented before and during movement, indicating automatic, external recoding of touch. Contrary to previous findings, tactile localization of congenitally blind participants, too, was affected by external coordinates, though only for stimuli presented before movement start. Furthermore, only the movement's start posture, but not the planned end posture affected blind individuals' tactile performance. Thus, integration of external coordinates in touch is established without vision, though more selectively than when vision has developed normally, and possibly restricted to movement contexts. The lack of modulation by the planned posture in congenitally blind participants suggests that external coordinates in this group are not mediated by motor efference copy. Instead the task-related frequent posture changes, that is, movement consequences rather than planning, appear to have induced their use of external coordinates.

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

    Directory of Open Access Journals (Sweden)

    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

  10. Postural threat influences conscious perception of postural sway.

    Science.gov (United States)

    Cleworth, Taylor W; Carpenter, Mark G

    2016-05-04

    This study examined how changes in threat influenced conscious perceptions of postural sway. Young healthy adults stood on a forceplate mounted to a hydraulic lift placed at two heights (0.8m and 3.2m). At each height, subjects stood quietly with eyes open and eyes closed for 60s. Subjects were instructed to either stand normal, or stand normal and track their perceived sway in the antero-posterior plane by rotating a hand-held potentiometer. Participants reported an increased level of fear, anxiety, arousal and a decreased level of balance confidence when standing at height. In addition, postural sway amplitude decreased and frequency increased at height. However, there were no effects of height on perceived sway. When standing under conditions of increased postural threat, sway amplitude is reduced, while sway perception appears to remain unchanged. Therefore, when threat is increased, sensory gain may be increased to compensate for postural strategies that reduce sway (i.e. stiffening strategy), thereby ensuring sufficient afferent information is available to maintain, or even increase the conscious perception of postural sway. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. The influence of different sitting postures on head/neck posture and muscle activity.

    Science.gov (United States)

    Caneiro, Joao Paulo; O'Sullivan, Peter; Burnett, Angus; Barach, Avi; O'Neil, David; Tveit, Orjan; Olafsdottir, Karolina

    2010-02-01

    To date the influence that specific sitting posture has on the head/neck posture and cervico-thoracic muscle activity has been insufficiently investigated. Therefore the aim of this study was to investigate whether three different thoraco-lumbar sitting postures affect head/neck posture and cervico-thoracic muscle activity. Twenty (10 men, 10 women) asymptomatic subjects were placed in 3 standardized thoraco-lumbar sitting postures (lumbo-pelvic, thoracic upright and slump) to investigate their influence on cervico-thoracic muscle activity and head/neck posture. There were significant differences in lumbar and thoracic curvatures in the 3 different sitting postures (Ppostures (P=0.015). Upper trapezius (UT) demonstrated no significant difference in muscle activation in the 3 sitting postures (Ppostures affect head/neck posture and cervico-thoracic muscle activity. It highlights the potential importance of thoraco-lumbar spine postural adjustment when training head/neck posture.

  12. 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.

  13. Sensory Organization of Balance Control in Children with Developmental Coordination Disorder

    Science.gov (United States)

    Fong, Shirley S. M.; Lee, Velma Y. L.; Pang, Marco Y. C.

    2011-01-01

    This study aimed to (1) compare functional balance performance and sensory organization of postural control between children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control and participation diversity among children with DCD. We recruited 81 children with DCD and 67 typically…

  14. Comparison of the postural and movement components during learning by dogs of an operant defensive reflex.

    Science.gov (United States)

    Shapovalova, K B; Chikhman, V N

    2003-09-01

    Chronic experiments on six dogs using a model of an operant defensive reflex associated with maintenance of flexion of the hindlimb of specified amplitude were performed to compare the characteristics of the postural and movement components during the learning process. Dogs were placed standing on four tension platforms. Signals were activated and data were recorded and stored using original PC programs. Original programs running on another PC were used to analyze the data. All dogs showed a series of characteristics for the appearance of a diagonal pattern of conditioned reflex posture rearrangement. During the period of complete formation of the "coordinated" program of the operant reflex (indicated by high performance criteria for execution of the operant task), the diagonal pattern of posture rearrangement was seen extremely rarely, in only occasional performances in calm dogs. It was only during the period of complete automatization of the movement habit that the diagonal pattern of postural rearrangement was seen consistently in all performances. By this time, there was a sharp increase in the tensogram amplitudes for all four limbs, which sharp increases in the correlation coefficients between individual tensogram performances. These results suggest that in the experimental conditions used here, the diagonal pattern of postural rearrangement appeared significantly later than the movement pattern needed for resolving the operant task. These data also lead to the conclusion that dogs can complete operant defensive limb movements associated with maintaining a specified flexor posture in the absence of preliminary rearrangement of the posture having the diagonal pattern.

  15. Emergence of postural patterns as a function of vision and translation frequency

    Science.gov (United States)

    Buchanan, J. J.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

    1999-01-01

    Emergence of postural patterns as a function of vision and translation frequency. We examined the frequency characteristics of human postural coordination and the role of visual information in this coordination. Eight healthy adults maintained balance in stance during sinusoidal support surface translations (12 cm peak to peak) in the anterior-posterior direction at six different frequencies. Changes in kinematic and dynamic measures revealed that both sensory and biomechanical constraints limit postural coordination patterns as a function of translation frequency. At slow frequencies (0.1 and 0.25 Hz), subjects ride the platform (with the eyes open or closed). For fast frequencies (1.0 and 1.25 Hz) with the eyes open, subjects fix their head and upper trunk in space. With the eyes closed, large-amplitude, slow-sway motion of the head and trunk occurred for fast frequencies above 0.5 Hz. Visual information stabilized posture by reducing the variability of the head's position in space and the position of the center of mass (CoM) within the support surface defined by the feet for all but the slowest translation frequencies. When subjects rode the platform, there was little oscillatory joint motion, with muscle activity limited mostly to the ankles. To support the head fixed in space and slow-sway postural patterns, subjects produced stable interjoint hip and ankle joint coordination patterns. This increase in joint motion of the lower body dissipated the energy input by fast translation frequencies and facilitated the control of upper body motion. CoM amplitude decreased with increasing translation frequency, whereas the center of pressure amplitude increased with increasing translation frequency. Our results suggest that visual information was important to maintaining a fixed position of the head and trunk in space, whereas proprioceptive information was sufficient to produce stable coordinative patterns between the support surface and legs. The CNS organizes

  16. Movement constraints on interpersonal coordination and communication.

    Science.gov (United States)

    Tolston, Michael T; Shockley, Kevin; Riley, Michael A; Richardson, Michael J

    2014-10-01

    The present study investigated how constraining movement affects interpersonal coordination and joint cognitive performance. Pairs of participants worked cooperatively to solve picture-puzzle tasks in which they conversed to identify differences between pictures in 3 degree-of-constraint conditions: both participants were free to move their hands (free-free; FF); both participants' hands were restrained (restrained-restrained; RR); and the hands of 1 participant were free while the hands of the other participant were restrained (free-restrained; FR). Eye tracking data were collected, and movement was measured at the waist, hand, and head. Data were analyzed using Cross-Recurrence Quantification Analysis (CRQ). Postural sway coordination, gaze coordination, and task performance were predicted to be highest in FF, followed by RR, and then by FR. Results showed the asymmetric FR condition generally exhibited lesser degrees of coordination than the symmetric Conditions FF and RR, and that the patterning of coordination in the symmetric conditions varied across the measured body segments. These results demonstrate that movement restraints affect not only interpersonal postural coordination, but also joint attention. Additionally, significant positive relationships were found between task performance and total amount of anterior-posterior movement measured at the head, hand and waist; number of utterances; and number of differences pairs found in the puzzles. These findings indicate a relationship between movement and task performance consistent with the hypotheses that both interpersonal coordination and cognitive performance are sensitive to local action constraints.

  17. Perinatal development of the motor systems involved in postural control.

    Science.gov (United States)

    Vinay, Laurent; Ben-Mabrouk, Faïza; Brocard, Frédéric; Clarac, François; Jean-Xavier, Céline; Pearlstein, Edouard; Pflieger, Jean-François

    2005-01-01

    Motor behaviors of some species, such as the rat and the human baby, are quite immature at birth. Here we review recent data on some of the mechanisms underlying the postnatal maturation of posture in the rat, in particular the development of pathways descending from the brain stem and projecting onto the lumbar enlargement of the spinal cord. A short-lasting depletion in serotonin affects both posture and the excitability of motoneurons. Here we try to extrapolate to human development and suggest that the abnormalities in motor control observed in childhood--e.g. deficits in motor coordination--might have their roots in the prenatal period, in particular serotonin depletion due to exposure to several environmental and toxicological factors during pregnancy.

  18. Effect of head and neck position on vertical ground reaction forces and interlimb coordination in the dressage horse ridden at walk and trot on a treadmill.

    Science.gov (United States)

    Weishaupt, M A; Wiestner, T; von Peinen, K; Waldern, N; Roepstorff, L; van Weeren, R; Meyer, H; Johnston, C

    2006-08-01

    Little is known in quantitative terms about the influence of different head-neck positions (HNPs) on the loading pattern of the locomotor apparatus. Therefore it is difficult to predict whether a specific riding technique is beneficial for the horse or if it may increase the risk for injury. To improve the understanding of forelimb-hindlimb balance and its underlying temporal changes in relation to different head and neck positions. Vertical ground reaction force and time parameters of each limb were measured in 7 high level dressage horses while being ridden at walk and trot on an instrumented treadmill in 6 predetermined HNPs: HNP1 - free, unrestrained with loose reins; HNP2 - neck raised, bridge of the nose in front of the vertical; HNP3 - neck raised, bridge of the nose behind the vertical; HNP4 - neck lowered and flexed, bridge of the nose considerably behind the vertical; HNP5 - neck extremely elevated and bridge of the nose considerably in front of the vertical; HNP6 - neck and head extended forward and downward. Positions were judged by a qualified dressage judge. HNPs were assessed by comparing the data to a velocity-matched reference HNP (HNP2). Differences were tested using paired t test or Wilcoxon signed rank test (Pwalk, stride duration and overreach distance increased in HNP1, but decreased in HNP3 and HNP5. Stride impulse was shifted to the forehand in HNP1 and HNP6, but shifted to the hindquarters in HNP5. At the trot, stride duration increased in HNP4 and HNP5. Overreach distance was shorter in HNP4. Stride impulse shifted to the hindquarters in HNP5. In HNP1 peak forces decreased in the forelimbs; in HNP5 peak forces increased in fore- and hindlimbs. HNP5 had the biggest impact on limb timing and load distribution and behaved inversely to HNP1 and HNP6. Shortening of forelimb stance duration in HNP5 increased peak forces although the percentage of stride impulse carried by the forelimbs decreased. An extremely high HNP affects functionality much more than an extremely low neck.

  19. Contributions of phase resetting and interlimb coordination to the adaptive control of hindlimb obstacle avoidance during locomotion in rats: a simulation study.

    OpenAIRE

    Aoi, Shinya; Kondo, Takahiro; Hayashi, Naohiro; Yanagihara, Dai; Aoki, Sho; Yamaura, Hiroshi; Ogihara, Naomichi; Funato, Tetsuro; Tomita, Nozomi; Senda, Kei; Tsuchiya, Kazuo

    2013-01-01

    Obstacle avoidance during locomotion is essential for safe, smooth locomotion. Physiological studies regarding muscle synergy have shown that the combination of a small number of basic patterns produces the large part of muscle activities during locomotion and the addition of another pattern explains muscle activities for obstacle avoidance. Furthermore, central pattern generators in the spinal cord are thought to manage the timing to produce such basic patterns. In the present study, we inve...

  20. Postural discomfort and perceived exertion in standardized box-holding postures.

    Science.gov (United States)

    Olendorf, M R; Drury, C G

    2001-12-15

    To help in the design or redesign of workplaces it would be helpful to know in advance the postural stress consequences of a wide range of body postures. This experiment evaluated 168 postures chosen to represent those in the Ovako Working-posture Analysing System (OWAS) using Rated Perceived Exertion (RPE) and Body Part Discomfort (BPD) measures. The postures comprised all combinations of three arm postures, four back postures, seven leg postures and two forces (weights of held boxes). Twelve male subjects held each posture for a fixed duration (20 s) before providing RPE and BPD ratings. Analysis of the ratings gave highly significant main effects, with the major driver being the object weight. As each factor was varied, the largest effect was on the body region corresponding to that factor. A simple main-effects-only additive model explained 91% of the variance of RPE means for the postures.

  1. Two aspects of feedforward postural control: anticipatory postural adjustments and anticipatory synergy adjustments.

    Science.gov (United States)

    Klous, Miriam; Mikulic, Pavle; Latash, Mark L

    2011-05-01

    We used the framework of the uncontrolled manifold hypothesis to explore the relations between anticipatory synergy adjustments (ASAs) and anticipatory postural adjustments (APAs) during feedforward control of vertical posture. ASAs represent a drop in the index of a multimuscle-mode synergy stabilizing the coordinate of the center of pressure in preparation to an action. ASAs reflect early changes of an index of covariation among variables reflecting muscle activation, whereas APAs reflect early changes in muscle activation levels averaged across trials. The assumed purpose of ASAs is to modify stability of performance variables, whereas the purpose of APAs is to change magnitudes of those variables. We hypothesized that ASAs would be seen before APAs and that this finding would be consistent with regard to the muscle-mode composition defined on the basis of different tasks and phases of action. Subjects performed a voluntary body sway task and a quick, bilateral shoulder flexion task under self-paced and reaction time conditions. Surface muscle activity of 12 leg and trunk muscles was analyzed to identify sets of 4 muscle modes for each task and for different phases within the shoulder flexion task. Variance components in the muscle-mode space and indexes of multimuscle-mode synergy stabilizing shift of the center of pressure were computed. ASAs were seen ∼ 100-150 ms prior to the task initiation, before APAs. The results were consistent with respect to different sets of muscle modes defined over the two tasks and different shoulder flexion phases. We conclude that the preparation for a self-triggered postural perturbation is associated with two types of anticipatory adjustments, ASAs and APAs. They reflect different feedforward processes within the hypothetical hierarchical control scheme, resulting in changes in patterns of covariation of elemental variables and in their patterns averaged across trials, respectively. The results show that synergies quantified

  2. 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...

  3. 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....

  4. A pinned polymer model of posture control

    CERN Document Server

    Chow, C C; Chow, Carson C; Collins, J J

    1995-01-01

    A phenomenological model of human posture control is posited. The dynamics are modelled as an elastically pinned polymer under the influence of noise. The model accurately reproduces the two-point correlation functions of experimental posture data and makes predictions for the response function of the postural control system. The physiological and clinical significance of the model is discussed.

  5. 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)

  6. Effect of posture-control insoles on function in children with cerebral palsy: Randomized controlled clinical trial

    OpenAIRE

    Pasini Neto Hugo; Grecco Luanda André; Christovão Thaluanna CL; Braun Luiz; Giannasi Lilian; Salgado Afonso Shiguemi; de Moura Renata Calhes; Carvalho Paulo de Tarso Camillo de; Corrêa João CF; Sampaio Luciana MM; Galli Manuela; Oliveira Claudia

    2012-01-01

    Abstract Introduction Cerebral palsy (CP) is a posture and movement disorder and different therapeutic modalities, such as the use of braces, have sought to favor selective motor control and muscle coordination in such patients. The aim of the proposed study is to determine the effect of the combination of posture-control insoles and ankle-foot orthoses (AFOs) improving functional limitation in children with CP. Methods/Design The sample will be composed of 24 children with CP between four an...

  7. Postural Control and Automaticity in Dyslexic Children: The Relationship between Visual Information and Body Sway

    Science.gov (United States)

    Barela, Jose A.; Dias, Josenaldo L.; Godoi, Daniela; Viana, Andre R.; de Freitas, Paulo B.

    2011-01-01

    Difficulty with literacy acquisition is only one of the symptoms of developmental dyslexia. Dyslexic children also show poor motor coordination and postural control. Those problems could be associated with automaticity, i.e., difficulty in performing a task without dispending a fair amount of conscious efforts. If this is the case, dyslexic…

  8. 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.

  9. 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.

  10. Postural analysis of nursing work.

    Science.gov (United States)

    Hignett, S

    1996-06-01

    Back pain in the nursing profession is an acknowledged wide spread occupational hazard. This study used OWAS (Ovako Working posture Analysis System) to measure the severity of the working postures adopted by nurses on Care of the Elderly wards when carrying out manual handling operations for animate and inanimate loads. Twenty-six nurses were observed on 31 occasions to obtain 4299 observations, these data were collected and processed using the OWASCO and OWASAN programs, and then analysed by grouping the results into defined patient (animate) handling and non-patient (inanimate) handling tasks. A statistical comparison was made between the two groups using the percentage of action categories two, three and four, to the total number of action categories. A significant difference (p < 0.05) was found, demonstrating that the percentage of harmful postures adopted during patient handling tasks was significantly higher than during non-patient handling tasks. This high level of postural stress and the poor track record of risk management within the Health Care Industry leads to the recommendation that an attitudinal change is needed to successfully address and reduce the manual handling burden which is currently being carried by the nursing staff.

  11. Poisson Coordinates.

    Science.gov (United States)

    Li, Xian-Ying; Hu, Shi-Min

    2013-02-01

    Harmonic functions are the critical points of a Dirichlet energy functional, the linear projections of conformal maps. They play an important role in computer graphics, particularly for gradient-domain image processing and shape-preserving geometric computation. We propose Poisson coordinates, a novel transfinite interpolation scheme based on the Poisson integral formula, as a rapid way to estimate a harmonic function on a certain domain with desired boundary values. Poisson coordinates are an extension of the Mean Value coordinates (MVCs) which inherit their linear precision, smoothness, and kernel positivity. We give explicit formulas for Poisson coordinates in both continuous and 2D discrete forms. Superior to MVCs, Poisson coordinates are proved to be pseudoharmonic (i.e., they reproduce harmonic functions on n-dimensional balls). Our experimental results show that Poisson coordinates have lower Dirichlet energies than MVCs on a number of typical 2D domains (particularly convex domains). As well as presenting a formula, our approach provides useful insights for further studies on coordinates-based interpolation and fast estimation of harmonic functions.

  12. Changes in Postural Syntax Characterize Sensory Modulation and Natural Variation of C. elegans Locomotion.

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    Roland F Schwarz

    2015-08-01

    Full Text Available Locomotion is driven by shape changes coordinated by the nervous system through time; thus, enumerating an animal's complete repertoire of shape transitions would provide a basis for a comprehensive understanding of locomotor behaviour. Here we introduce a discrete representation of behaviour in the nematode C. elegans. At each point in time, the worm's posture is approximated by its closest matching template from a set of 90 postures and locomotion is represented as sequences of postures. The frequency distribution of postural sequences is heavy-tailed with a core of frequent behaviours and a much larger set of rarely used behaviours. Responses to optogenetic and environmental stimuli can be quantified as changes in postural syntax: worms show different preferences for different sequences of postures drawn from the same set of templates. A discrete representation of behaviour will enable the use of methods developed for other kinds of discrete data in bioinformatics and language processing to be harnessed for the study of behaviour.

  13. Methodological and interpretive issues in posture-cognition dual-tasking in upright stance.

    Science.gov (United States)

    Fraizer, E V; Mitra, Subhobrata

    2008-02-01

    The traditionally separate researches on cognitive functions and basic coordinations such as stance and locomotion are coming together in the study of posture-cognition dual-tasking. The importance of this growing research area lies not only in the ubiquitous coexistence of postural and cognitive tasks but also in the observation that posture control very often has the dual role of securing the body's safety and balance while also providing a versatile, stable physical substrate well-suited to perception-action tasks. Although dual-task investigations strongly suggest that posture control and higher level cognition have common resource requirements, inconsistencies in the data and differences in experimental design make it difficult to distill a fuller understanding of the specific mechanisms behind posture-cognition dual-tasking. In this paper, we review the literature on upright standing with concurrent cognitive tasks, and highlight paradigmatic variations that possibly contribute to dual-task data differences. Implications arising from theoretical assumptions made about the role of postural control in the concurrent performance of cognitive tasks are also discussed.

  14. Development of postural adjustments during reaching in typically developing infants from 4 to 18 months.

    Science.gov (United States)

    van Balen, Lieke C; Dijkstra, Linze Jaap; Hadders-Algra, Mijna

    2012-07-01

    Knowledge on the development of postural adjustments during infancy, in particular on the development of postural muscle coordination, is limited. This study aimed at the evaluation of the development of postural control during reaching in a supported sitting condition. Eleven typically developing infants participated in the study and were assessed at the ages of 4, 6, 10 and 18 months. We elicited reaching movements by presenting small toys at an arm's length distance, whilst activity of multiple arm, neck and trunk muscles was recorded using surface EMG. A model-based computer algorithm was used to detect the onset of phasic muscle activity. The results indicated that postural muscle activity during reaching whilst sitting supported is highly variable. Direction-specific postural activity was inconsistently present from early age onwards and increased between 10 and 18 months without reaching a 100 % consistency. The dominant pattern of activation at all ages was the 'complete pattern', in which all direction-specific muscles were recruited. At 4 months, a slight preference for top-down recruitment existed, which was gradually replaced by a preference for bottom-up recruitment. We conclude that postural control during the ecological task of reaching during supported sitting between 4 and 18 months of age is primarily characterized by variation. Already from 4 months onwards, infants are-within the variation-sometimes able to select muscle recruitment strategies that are optimal to the task at hand.

  15. Development of temporal and spatial bimanual coordination during childhood.

    Science.gov (United States)

    de Boer, Betteco J; Peper, C E; Beek, Peter J

    2012-10-01

    Developmental changes in bimanual coordination were examined in four age groups: 6/7, 10/11, 14/15 years, and young adults. Temporal coupling was assessed through the stabilizing contributions of interlimb interactions related to planning, error correction, and reflexes during rhythmic wrist movements, by comparing various unimanual and bimanual tasks involving passive and active movements. Spatial coupling was assessed via bimanual line-circle drawing. With increasing age, temporal stability improved. Relative contributions of planning and reflex interactions to the achieved stability did not change, whereas error correction improved. In-phase and antiphase coordination developed at similar rates; implications of this result were discussed in terms of mirror-activity inhibition. Overall spatial drawing performance (circularity, variability, smoothness) improved with age, and spatial interference was smaller in adults than children. Whereas temporal coupling increased from 6/7 years to adulthood, spatial coupling changed mainly after 14/15 years. This difference in the development of temporal and spatial coupling corresponds to the anterior-posterior direction of corpus callosum myelination as reported in the literature.

  16. Does observation of postural imbalance induce a postural reaction?

    Directory of Open Access Journals (Sweden)

    Banty Tia

    Full Text Available BACKGROUND: Several studies bring evidence that action observation elicits contagious responses during social interactions. However automatic imitative tendencies are generally inhibited and it remains unclear in which conditions mere action observation triggers motor behaviours. In this study, we addressed the question of contagious postural responses when observing human imbalance. METHODOLOGY/PRINCIPAL FINDINGS: We recorded participants' body sway while they observed a fixation cross (control condition, an upright point-light display of a gymnast balancing on a rope, and the same point-light display presented upside down. Our results showed that, when the upright stimulus was displayed prior to the inverted one, centre of pressure area and antero-posterior path length were significantly greater in the upright condition compared to the control and upside down conditions. CONCLUSIONS/SIGNIFICANCE: These results demonstrate a contagious postural reaction suggesting a partial inefficiency of inhibitory processes. Further, kinematic information was sufficient to trigger this reaction. The difference recorded between the upright and upside down conditions indicates that the contagion effect was dependent on the integration of gravity constraints by body kinematics. Interestingly, the postural response was sensitive to habituation, and seemed to disappear when the observer was previously shown an inverted display. The motor contagion recorded here is consistent with previous work showing vegetative output during observation of an effortful movement and could indicate that lower level control facilitates contagion effects.

  17. Geometric morphometrics as a tool for improving the comparative study of behavioural postures

    Science.gov (United States)

    Fureix, Carole; Hausberger, Martine; Seneque, Emilie; Morisset, Stéphane; Baylac, Michel; Cornette, Raphaël; Biquand, Véronique; Deleporte, Pierre

    2011-07-01

    Describing postures has always been a central concern when studying behaviour. However, attempts to compare postures objectively at phylogenetical, populational, inter- or intra-individual levels generally either rely upon a few key elements or remain highly subjective. Here, we propose a novel approach, based on well-established geometric morphometrics, to describe and to analyse postures globally (i.e. considering the animal's body posture in its entirety rather than focusing only on a few salient elements, such as head or tail position). Geometric morphometrics is concerned with describing and comparing variation and changes in the form (size and shape) of organisms using the coordinates of a series of homologous landmarks (i.e. positioned in relation to skeletal or muscular cues that are the same for different species for every variety of form and function and that have derived from a common ancestor, i.e. they have a common evolutionary ancestry, e.g. neck, wings, flipper/hand). We applied this approach to horses, using global postures (1) to characterise behaviours that correspond to different arousal levels, (2) to test potential impact of environmental changes on postures. Our application of geometric morphometrics to horse postures showed that this method can be used to characterise behavioural categories, to evaluate the impact of environmental factors (here human actions) and to compare individuals and groups. Beyond its application to horses, this promising approach could be applied to all questions involving the analysis of postures (evolution of displays, expression of emotions, stress and welfare, behavioural repertoires…) and could lead to a whole new line of research.

  18. Postural control in patients with lumbar disc herniation in the early postoperative period.

    Science.gov (United States)

    Sipko, Tomasz; Chantsoulis, Marzena; Kuczyński, Michał

    2010-03-01

    Chronic spinal disc disease leads to disorders in postural movement coordination. An incorrect asymmetrical movement pattern for the lower limbs loading impairs proprioception and deteriorates postural stability, particularly when the vision is occluded. The standard surgical treatment improves biomechanical conditions in the lumbar spine, reduces pain, yet does it reduce the stability deficit in the upright position? An answer to the latter question would help work out targeted therapy to improve postural stability. We hypothesized that the standard surgical treatment would improve postural stability reflected by decreased sway variability accounting for better use of proprioceptive inputs postoperatively. Thirty-nine patients with lumbar disc herniation participated in the study. Their postural sway was recorded in anterior/posterior and medial/lateral planes with their eyes open or closed (EC) before and after surgery. The variability, range, mean velocity of the recorded time series and the area of the ellipse enclosed by the statokinesiogram were used as measures of postural stability. Preoperatively, EC condition resulted in an increased variability and mean velocity of postural sway, while postoperatively it caused an increase in sway mean velocity and sway area only with no effect on sway variability and range. The comparison of the balance before and after the surgery in the EC condition showed significant decrease in all parameters. In the early postoperative period, the patients recover the ability to control their postural sway in EC within normal limits, however, at the expense of significantly increased frequency of corrective torques. It is probably a transient short-term strategy needed to compensate for the recovery phase when the normal weighting factors for all afferents are being reestablished. We propose that this transient postoperative period may be the best timing of therapeutic intervention targeted at facilitating and reinforcing the

  19. Atlas morphology in relation to craniofacial morphology and head posture.

    Science.gov (United States)

    Sandikçioğlu, M; Skov, S; Solow, B

    1994-04-01

    The associations between dimensions of the first cervical vertebra, atlas, and a representative set of craniofacial and postural variables were studied on cephalometric radiographs of a sample of 103 adult males aged 22-30 years, recorded in the natural head position (mirror position). Atlas morphology was expressed by nine variables, linear and angular craniofacial dimensions by 27 variables, and head and cervical posture by seven variables. A pattern of low but significant correlations was found. Although the correlations were low, the study confirmed that the dimensions of the atlas vertebra reflect associations between cranio-cervical posture and craniofacial morphology. Negative correlations were found between the height of the posterior arch of atlas and the inclination of the mandible and the maxilla to the anterior cranial base. Low positive correlations between the height of the anterior arch and vertical facial dimensions reflect the general co-ordination of the vertical growth of the face and the cervical column. Moreover, the pattern of correlations between the atlanto-cranial angle and facial morphology suggests that in changes of the cranio-cervical angle, atlas follows the cervical column.

  20. 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.

  1. Postural control in blind subjects

    Directory of Open Access Journals (Sweden)

    Antonio Vinicius Soares

    2011-12-01

    Full Text Available Objective: To analyze postural control in acquired and congenitally blind adults. Methods: A total of 40 visually impaired adults participated in the research, divided into 2 groups, 20 with acquired blindness and 20 with congenital blindness - 21 males and 19 females, mean age 35.8 ± 10.8. The Brazilian version of Berg Balance Scale and the motor domain of functional independence measure were utilized. Results: On Berg Balance Scale the mean for acquired blindness was 54.0 ± 2.4 and 54.4 ± 2.5 for congenitally blind subjects; on functional independence measure the mean for acquired blind group was 87.1 ± 4.8 and 87.3 ± 2.3 for congenitally blind group. Conclusion: Based upon the scale used the results suggest the ability to control posture can be developed by compensatory mechanisms and it is not affected by visual loss in congenitally and acquired blindness.

  2. Computerized Determination of Optimal Postures

    Science.gov (United States)

    Coblentz, J. F.; Gueneau, P.; Bonjour, N.

    1986-07-01

    An intelligent system for automatic research of optimal postures in ergonomics has been developed at the Laboratoire d'Anthropologie Appliquee. A dynamic programming algorithm allows the automatic graphic research for an eight degrees of freedom bidimensional model. The different range of motions and acceptable ergonomic intervals are used for each articulation. This method is going to be integrated in the C.A.D. system of ERGODATA.

  3. Postural Control in Deaf Children

    Directory of Open Access Journals (Sweden)

    Amir-Abbas Ebrahimi

    2017-02-01

    Full Text Available This cross-sectional study aimed to determine the reliability of static control evaluation with Synapsys Posturography System (SPS, Marseille, France and to compare the static postural control of deaf children with typically developing children. This study was conducted in 2 phases on 81 children of 7 to 12 years old in Tehran schools. The first phase examined the reliability of static balance evaluation with SPS. In this phase, a total of 12 children with typical development were evaluated and then do a re-test 1 week later. In the second phase, 30 children with profound sensorineural hearing loss (SNHL and high risk in their balance (selected from Baghcheban Schools for the Deaf as the experimental group, and 37 children with typical development (selected randomly from 2 primary schools for girls and boys in District 12 of Tehran Department of Education as control group were enrolled in the study. They were all placed under sensory organization test evaluation. Based on the results of intraclass correlation coefficient (ICC, the unilateral random effects model, test-retest reliability in different sensory conditions, the moderate to excellent results were obtained (ICC between 0.68 and 0.94. Also, the mean displacement of pressure center in all sensory conditions, the limits of stability (LOS area, the overall balance scores, and scores for balance sensory ratio (except the somatosensory ratio of children with typical development were better than the deaf peers (P˂0.05. The SPS has acceptable reliability to evaluate static posture in children between the ages of 7 and 12 years. Furthermore, deaf children as compared to children with typical development had a lower static postural control in all sensory conditions. This finding confirms the need to examine the postural control for identifying the extent of sensory deficit that has caused poor balance function, and also the need for early intervention to address the balance deficit in deaf

  4. 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.

  5. Posture alters human resting-state.

    Science.gov (United States)

    Thibault, Robert T; Lifshitz, Michael; Jones, Jennifer M; Raz, Amir

    2014-09-01

    Neuroimaging is ubiquitous; however, neuroimagers seldom investigate the putative impact of posture on brain activity. Whereas participants in most psychological experiments sit upright, many prominent neuroimaging techniques (e.g., functional magnetic resonance imaging (fMRI)) require participants to lie supine. Such postural discrepancies may hold important implications for brain function in general and for fMRI in particular. We directly investigated the effect of posture on spontaneous brain dynamics by recording scalp electrical activity in four orthostatic conditions (lying supine, inclined at 45°, sitting upright, and standing erect). Here we show that upright versus supine posture increases widespread high-frequency oscillatory activity. Our electroencephalographic findings highlight the importance of posture as a determinant in neuroimaging. When generalizing supine imaging results to ecological human cognition, therefore, cognitive neuroscientists would benefit from considering the influence of posture on brain dynamics.

  6. Development of Postural Muscles and Their Innervation

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    J. IJkema-Paassen

    2005-01-01

    Full Text Available Control of posture is a prerequisite for efficient motor performance. Posture depends on muscles capable of enduring contractions, whereas movements often require quick, forceful muscle actions. To serve these different goals, muscles contain fibers that meet these different tasks. Muscles with strong postural functions mainly consist of slow muscle fibers with a great resistance against fatigue. Flexor muscles in the leg and arm muscles are mainly composed of fast muscle fibers producing relatively large forces that are rapidly fatigable. Development of the neuromuscular system continues after birth. We discuss in the human baby and in animal experiments changes in muscle fiber properties, regression from polyneural into mononeural innervation, and developmental changes in the motoneurons of postural muscles during that period. The regression of poly-neural innervation in postural muscles and the development of dendrite bundles of their motoneurons seem to be linked to the transition from the immature into the adult-like patterns of moving and postural control.

  7. Postural Stability is Altered by Blood Shift

    Science.gov (United States)

    Marais, M.; Denise, P.; Guincetre, J. Y.; Normand, H.

    2008-06-01

    Non-vestibular influences as shift in blood volume changed perception of body posture. Then, factors affecting blood shift may alter postural control. The purpose of our study was to investigate the effects of leg venous contention on postural stability. Twelve subjects were studied on a balance plate for 5 minutes with the eyes closed, in 3 conditions: with no leg venous contention or grade 1 and 3 support stockings. Standard deviation of x and y position was calculated before and after the closure of the eyes. Strong venous contention altered postural stability, after the eyes were closed, during the first 10 s of standing. As support stockings prevent blood shift induced by upright posture, this result is in line with the hypothesis that blood shifts influence the perception of body orientation and postural control among others factors as vision, vestibular inputs... This strong venous contention could induce an increase of fall.

  8. Toddlers actively reorganize their whole body coordination to maintain walking stability while carrying an object.

    Science.gov (United States)

    Hsu, Wen-Hao; Miranda, Daniel L; Chistolini, Trevor L; Goldfield, Eugene C

    2016-10-01

    Balanced walking involves freely swinging the limbs like pendula. However, children immediately begin to carry objects as soon as they can walk. One possibility for this early skill development is that whole body coordination during walking may be re-organized into loosely coupled collections of body parts, allowing children to use their arms to perform one function, while the legs perform another. Therefore, this study examines: 1) how carrying an object affects the coordination of the arms and legs during walking, and 2) if carrying an object influences stride length and width. Ten healthy toddlers with 3-12 months of walking experience were recruited to walk barefoot while carrying or not carrying a small toy. Stride length, width, speed, and continuous relative phase (CRP) of the hips and of the shoulders were compared between carrying conditions. While both arms and legs demonstrated destabilization and stabilization throughout the gait cycle, the arms showed a reduction in intra-subject coordination variability in response to carrying an object. Carrying an object may modify the function of the arms from swinging for balance to maintaining hold of an object. The observed period-dependent changes of the inter-limb coordination of the hips and of the shoulders also support this interpretation. Overall, these findings support the view that whole-body coordination patterns may become partitioned in particular ways as a function of task requirements.

  9. Objective measurement of posture and posture transitions in the pre-school child.

    Science.gov (United States)

    Davies, Gwyneth; Reilly, John J; Paton, James Y

    2012-11-01

    Recent evidence suggests that between-individual variation in posture and posture transitions may have important health consequences in adults. The early life development of between-individual variation in posture and posture transitions has not been studied, and the physiological consequences of such variations in childhood are unknown, largely because of the absence of objective methods for measuring posture and posture transitions in young children. This study aimed to examine the objective measurement of posture transitions in pre-school children with the activPAL™ monitor (PAL Technologies, Glasgow). Single-unit activity monitors such as the activPAL™ have a limited output, with data categorized as 'sit/lie', 'stand' or 'walk' and the consequences of this for measurement of posture transitions in young children are unknown. Thirty children (mean age 4.1 years) were videoed for 1 h in nursery while wearing an activPAL™. Video was analysed on a second-by-second basis, with all postures categorized. From direct observation, time spent was sit/lie 46%; stand 35%; walk/run 16%; 3% was spent in heterogeneous non-sit/lie/upright postures (crawl, crouch, and kneel up). Despite these 'non-standard' postures being responsible for a low proportion of time, posture transitions involving them contributed to 34% of total transitions. There was a significant rank-order correlation (r = 0.79, p posture transitions measured by activPAL™ and by direct observation. 'Non-standard' postures in young children are probably not a problem if the aim is to measure total time sedentary or active, and the activPAL™ may measure between-individual variation in transitions adequately in young children. However, non-standard postures may present problems for the detailed characterization of posture transitions in early childhood.

  10. Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures

    OpenAIRE

    Han Suk Lee; Hyung Kuk Chung; Sun Wook Park

    2015-01-01

    Objective. To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP). Methods. In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA) test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation...

  11. New Angles on Motor and Sensory Coordination in Learning Disabilities.

    Science.gov (United States)

    Goldey, Ellen S.

    1998-01-01

    Provides an overview of presentations that were included in the Medical Symposium at the 1998 Learning Disabilities Association conference. The symposium addressed vestibular control and eye movement, postural sway and balance, cerebellar dysfunction, the role of the frontal lobe, developmental coordination disorder, and sensory integration…

  12. Does forward head posture affect postural control in human healthy volunteers?

    Science.gov (United States)

    Silva, Anabela G; Johnson, Mark I

    2013-06-01

    Proprioceptive afferent input from neck muscles plays an important role in postural control. Forward head posture has the potential to impair proprioceptive information from neck muscles and contribute to postural control deficits in patients with neck pain. This study investigated whether induced forward head posture affects postural control in healthy participants when compared to natural head posture. Centre of pressure sway area, distance covered and mean velocity were measured during 30s of static standing using a force platform with 25 healthy individuals (mean age ± SD = 20.76 ± 2.19 years) in 8 different conditions. Base of support, eyes open or closed and natural or forward head posture varied within these testing conditions. The majority of comparisons between natural and forward head posture were not statistically significant (p>0.05). This suggests that induced forward head posture in young healthy adults does not challenge them enough to impair postural control. Future studies should evaluate whether forward head posture affects postural control of individuals with chronic neck pain.

  13. 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.

  14. 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.

  15. Postural control in sitting children with cerebral palsy

    NARCIS (Netherlands)

    Brogren, E; Hadders-Algra, M; Forssberg, H

    1998-01-01

    Children with cerebral palsy (CP) display postural problems, largely interfering with daily life activities. Clarification of neural mechanisms controlling posture in these children could serve as a base for more successful intervention. Studies on postural adjustments following horizontal forward a

  16. Postural control in sitting children with cerebral palsy

    NARCIS (Netherlands)

    Brogren, E; Hadders-Algra, M; Forssberg, H

    1998-01-01

    Children with cerebral palsy (CP) display postural problems, largely interfering with daily life activities. Clarification of neural mechanisms controlling posture in these children could serve as a base for more successful intervention. Studies on postural adjustments following horizontal forward a

  17. THE ROLE OF LEG AND TRUNK MUSCLES PROPRIOCEPTION ON STATIC AND DYNAMIC POSTURAL CONTROL

    Directory of Open Access Journals (Sweden)

    SEYED Hossein Hosseinimehr

    2010-04-01

    Full Text Available The proprioception information is a prerequisite for balance, body’s navigation system, and the movement coordinator. Due to changes between the angles of ankle, knee, and hip joints the aforementioned information are important in the coordination of the limbs and postural balance. The aim of this study was to investigate therole of leg and trunk muscles proprioception on static and dynamic postural control. Thirty males students of physical education and sport sciences (age =21.23 ± 2.95 years, height = 170.4 ± 5.1 cm, and weight = 70.7 ± 5.6 kg participated in this study volunteered. Vibration (100HZ was used to disturb of proprioception. Vibrationoperated on leg muscle (gasterocnemius and trunk muscles (erector spine muscle, at L1 level. Leg stance time and Star Excursion Balance Test were used for evaluation of static and dynamic postural control respectively.Subjects performed pre and post (with operated vibration leg stance time and star excursion balance test. Paired sample test used for investigation the effect of vibration on leg and trunk muscles in static and dynamic postural control. Result of this study showed in static postural control, there is no significant difference between pre and post test (operated vibration in leg and trunk muscles (p≤0.05. In contrast there is significant difference indynamic postural control between pre and post test in leg muscles in 8 directions of star excursion balance test (p≤0.05 while there is only significant difference in trunk muscle in antrolateral and lateral of star excursion balance test (p≤0.05. During physical training such conditions like fatigue and injury can disturbproprioceptions’ information. Thus, due to the importance of this information we recommend that coaches'additionally specific trainings any sport used specific exercises to enhance the proprioception information

  18. Race or Resource? BMI, Race, and Other Social Factors as Risk Factors for Interlimb Differences among Overweight Breast Cancer Survivors with Lymphedema

    Directory of Open Access Journals (Sweden)

    Lorraine T. Dean

    2016-01-01

    Full Text Available Introduction. High BMI is a risk factor for upper body breast cancer-related lymphedema (BCRL onset. Black cancer survivors are more likely to have high BMI than White cancer survivors. While observational analyses suggest up to 2.2 times increased risk of BCRL onset for Black breast cancer survivors, no studies have explored race or other social factors that may affect BCRL severity, operationalized by interlimb volume difference (ILD. Materials and Methods. ILD was measured by perometry for 296 overweight (25 > BMI 6 months from treatment in the WISER Survivor trial. Multivariable linear regression examined associations between social and physical factors and ILD. Results. Neither Black race (−0.26, p=0.89 nor BMI (0.22, p=0.10 was associated with ILD. Attending college (−4.89, p=0.03 was the strongest factor associated with ILD, followed by having more lymph nodes removed (4.75, p=0.01, >25% BCRL care adherence (4.10, p=0.01, and years since treatment (0.55, p<0.001. Discussion. Neither race nor BMI was associated with ILD among overweight cancer survivors. Education, a proxy for resource level, was the strongest factor associated with greater ILD. Tailoring physical activity and weight loss interventions designed to address BCRL severity by resource rather than race should be considered.

  19. Motor Coordination in Autism Spectrum Disorders: A Synthesis and Meta-Analysis

    Science.gov (United States)

    Fournier, Kimberly A.; Hass, Chris J.; Naik, Sagar K.; Lodha, Neha; Cauraugh, James H.

    2010-01-01

    Are motor coordination deficits an underlying cardinal feature of Autism Spectrum Disorders (ASD)? Database searches identified 83 ASD studies focused on motor coordination, arm movements, gait, or postural stability deficits. Data extraction involved between-group comparisons for ASD and typically developing controls (N = 51). Rigorous…

  20. [Postural examination in daily occlusodontology].

    Science.gov (United States)

    Serviere, F

    1989-03-01

    According to the osteopathic and chiropractic concepts, facing a TMJ problem, the practitioner has to determine if the trouble observed in the stomatognatic apparatus is the cause or the effect of the structural problems present anywhere else in the body. The postural examination allows to answer this question. Tow techniques can be used. First a static and dynamic posture test proposed by Bricot. The level of the cranium, the eyes, the shoulders, the wrists, the pelvis and the ankles is analysed, from a front view; from the side, the gravity line is inspected: vertex, auditory meatus, shoulder, hip joint, anterior side of the tibia, ankle joint. The vertical posture can be studied from the front: the arms are held straight and the antero-posterior length between the fingers is measured. From the back, one notes the recoil of the buttocks on one side. An ocular convergence test is performed. Then one uses a Romberg test (oscillation of the body when the eyes are closed), and a Fukuda stepping test. The patient is then asked to bite on a compress, and the same exams are redone. If no change occurs, we are dealing with an ascending problem: the origin of the problem is not the stomatognathic system. The second technique is the Meerssemann test that needs the practice of Applied Kinesiology muscle testing. The patient is lying supine and one tests: the dental occlusion, the two TMJs, the temporal muscles, masseters, pterygoids, sterno-cleido-mastoids, upper tapezius, left and right sacro-iliac joints, psoas muscles bilaterally.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Impaired H-Reflex Gain during Postural Loaded Locomotion in Individuals Post-Stroke.

    Directory of Open Access Journals (Sweden)

    Jing Nong Liang

    Full Text Available Successful execution of upright locomotion requires coordinated interaction between controllers for locomotion and posture. Our earlier research supported this model in the non-impaired and found impaired interaction in the post-stroke nervous system during locomotion. In this study, we sought to examine the role of the Ia afferent spinal loop, via the H-reflex response, under postural influence during a locomotor task. We tested the hypothesis that the ability to increase stretch reflex gain in response to postural loads during locomotion would be reduced post-stroke.Fifteen individuals with chronic post-stroke hemiparesis and 13 non-impaired controls pedaled on a motorized cycle ergometer with specialized backboard support system under (1 seated supported, and (2 non-seated postural-loaded conditions, generating matched pedal force outputs of two levels. H-reflexes were elicited at 90° crank angle.We observed increased H-reflex gain with postural influence in non-impaired individuals, but a lack of increase in individuals post-stroke. Furthermore, we observed decreased H-reflex gain at higher postural loads in the stroke-impaired group.These findings suggest an impaired Ia afferent pathway potentially underlies the defects in the interaction between postural and locomotor control post-stroke and may explain reduced ability of paretic limb support during locomotor weight-bearing in individuals post-stroke.These results support the judicious use of bodyweight support training when first helping individuals post-stroke to regain locomotor pattern generation and weight-bearing capability.

  2. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    Overview From a technical perspective, CMS has been in “beam operation” state since 6th November. The detector is fully closed with all components operational and the magnetic field is normally at the nominal 3.8T. The UXC cavern is normally closed with the radiation veto set. Access to UXC is now only possible during downtimes of LHC. Such accesses must be carefully planned, documented and carried out in agreement with CMS Technical Coordination, Experimental Area Management, LHC programme coordination and the CCC. Material flow in and out of UXC is now strictly controlled. Access to USC remains possible at any time, although, for safety reasons, it is necessary to register with the shift crew in the control room before going down.It is obligatory for all material leaving UXC to pass through the underground buffer zone for RP scanning, database entry and appropriate labeling for traceability. Technical coordination (notably Stephane Bally and Christoph Schaefer), the shift crew and run ...

  3. Evaluation of head and neck postures

    NARCIS (Netherlands)

    Delleman, N.J.

    2000-01-01

    This paper describes the literature and two experiments on the evaluation of head and neck postures. It is concluded that health and safety professiona1s and ergonomists during posture evaluation should consider neck flexion/extension (head vs. trunk), besides the traditionally used inclination of t

  4. 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…

  5. 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…

  6. Compromising Postural Balance in the Elderly

    NARCIS (Netherlands)

    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

  7. Compromising Postural Balance in the Elderly

    NARCIS (Netherlands)

    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

  8. Current World Geostrategic Posture and Its Prospect

    Institute of Scientific and Technical Information of China (English)

    Lin Limin

    2004-01-01

    @@ Being affected by Iraq war, the Korean nuclear crisis, the readjustment of the U.S. military strategy and in-depth development of terrorism and anti-terrorist struggles, the world geostrategic posture has undergone great changes. To observe and analyze these new changes will help us better understand the future trends of the world geostrategic posture.

  9. Evaluation of head and neck postures

    NARCIS (Netherlands)

    Delleman, N.J.

    2000-01-01

    This paper describes the literature and two experiments on the evaluation of head and neck postures. It is concluded that health and safety professiona1s and ergonomists during posture evaluation should consider neck flexion/extension (head vs. trunk), besides the traditionally used inclination of

  10. Age-related changes in postural control to the demands of a precision task.

    Science.gov (United States)

    Yeh, Ting-Ting; Cinelli, Michael E; Lyons, James L; Lee, Timothy D

    2015-12-01

    Optimal sensorimotor integration is needed to maintain the precision of a visuomotor postural task. Furthermore, cognitive resources have been suggested to be involved in maintaining balance, especially in older adults. This study investigated how older and younger adults differed in employing sensorimotor strategies in a dual-task situation. Older (age 65-84 years) and younger adults (age 19-30 years) performed a visually-based, postural tracking task in different body orientations (from 0° to 45°), which necessitated slightly different task goals. On some trials, participants performed a concurrent silent arithmetic task with the visuomotor tracking task. The results demonstrated that sensorimotor control declined with age. Older adults showed greater medial-lateral center of pressure variability compared to younger adults in the precision task. Younger adults displayed a trend to decrease anterior-posterior variability, but older adults exhibited an opposite trend when the body orientation changed from 0° to 45°. The addition of a dual-task situation decreased overall postural variability in both age groups. Age-related changes in postural control may degrade the flexible coordination of the sensory feedback and motor execution. This study suggested that medial-lateral stability may be more sensitive to this age-related decline and may be closely associated with postural instability and falls.

  11. Effect of intermittent feedback control on robustness of human-like postural control system

    Science.gov (United States)

    Tanabe, Hiroko; Fujii, Keisuke; Suzuki, Yasuyuki; Kouzaki, Motoki

    2016-03-01

    Humans have to acquire postural robustness to maintain stability against internal and external perturbations. Human standing has been recently modelled using an intermittent feedback control. However, the causality inside of the closed-loop postural control system associated with the neural control strategy is still unknown. Here, we examined the effect of intermittent feedback control on postural robustness and of changes in active/passive components on joint coordinative structure. We implemented computer simulation of a quadruple inverted pendulum that is mechanically close to human tiptoe standing. We simulated three pairs of joint viscoelasticity and three choices of neural control strategies for each joint: intermittent, continuous, or passive control. We examined postural robustness for each parameter set by analysing the region of active feedback gain. We found intermittent control at the hip joint was necessary for model stabilisation and model parameters affected the robustness of the pendulum. Joint sways of the pendulum model were partially smaller than or similar to those of experimental data. In conclusion, intermittent feedback control was necessary for the stabilisation of the quadruple inverted pendulum. Also, postural robustness of human-like multi-link standing would be achieved by both passive joint viscoelasticity and neural joint control strategies.

  12. Acute effects of Dry Immersion on kinematic characteristics of postural corrective responses

    Science.gov (United States)

    Sayenko, D. G.; Miller, T. F.; Melnik, K. A.; Netreba, A. I.; Khusnutdinova, D. R.; Kitov, V. V.; Tomilovskaya, E. S.; Reschke, M. F.; Gerasimenko, Y. P.; Kozlovskaya, I. B.

    2016-04-01

    Impairments in balance control are inevitable following exposure to microgravity. However, the role of particular sensory system in postural disorders at different stages of the exposure to microgravity still remains unknown. We used a method called Dry Immersion (DI), as a ground-based model of microgravity, to elucidate the effects of 6-h of load-related afferent inputs on kinematic characteristics of postural corrective responses evoked by pushes to the chest of different intensities during upright standing. The structure of postural corrective responses was altered following exposure to DI, which was manifested by: (1) an increase of the ankle and knee flexion during perturbations of medium intensity, (2) the lack of the compensatory hip extension, as well as diminished knee and ankle flexion with a further increase of the perturbation intensity to submaximal level. We suggest that the lack of weight-bearing increases the reactivity of the balance control system, whereas the ability to scale the responses proportionally to the perturbation intensity decreases. Disrupted neuromuscular coordination of postural corrective responses following DI can be attributed to adaptive neural modifications on the spinal and cortical levels. The present study provides evidence that even a short-term lack of load-related afferent inputs alters kinematic patterns of postural corrective responses, and can result in decreased balance control. Because vestibular input is not primarily affected during the DI exposure, our results indicate that activity and the state of the load-related afferents play critical roles in balance control following real or simulated microgravity.

  13. Posture And Dorsal Shape At A Sitted Workstation

    Science.gov (United States)

    Lepoutre, F. X.; Cloup, P.; Guerra, T. M.

    1986-07-01

    The ergonomic analysis of a control or a supervision workstation for a vehicle or a process, necessitates to take into account the biomecanical visuo-postural system. The measurements, which are necessary to do, must give informations about the spatial direction of the limbs, the dorsal shape, eventually the eyes direction, and the postural evolution during the working time. More, the smallness of the work station, the backrest and sometime a vibratory environment made use specific, strong and small devices wich do not disturb the operator. The measurement system which we propose is made of an optical device. This system is studied in relation with the french "Institute de Recherche pour les Transports" for an ergonomic analysis of a truck cabin. The optical device consists on placing on the body of the driver on particular places materializing specially members and trunck joint points, some drops which reflect the infra-red raies coming from a specific light. Several cameras whose relative positions depend on the experiment site, transmit video signals to the associated treatment systems which extract the coordinates (Xi, Yi) of each drop in the observation scope of any camera. By regrouping the informations obtained from every view, it is possible to obtain the spatial drop position and then to restore the individual's posture in three dimensions. Therefore, this device doesn't enable us, in consideration of the backrest, to analyse the dorsal posture, which is important with regard to dorsal pains frequency. For that reason, we complete the measurements by using a "curvometer". This device consists of a flexible stick fixed upon the individual back with elastic belts, whose distorsions (curvature in m-1) are measured, in the individual's sagittal plane, with 4 strain gauges pairs; located approximately at the level of vertebra D1, D6, D10 and L3. A fifth measurement, concerning the inclination (in degree) of the lower part of the stick, makes it is possible to

  14. A Developmental Study of Static Postural Control and Superimposed Arm Movements in Normal and Slowly Developing Children.

    Science.gov (United States)

    Fisher, Janet M.

    Selected electromyographic parameters underlying static postural control in 4, 6, and 8 year old normally and slowly developing children during performance of selected arm movements were studied. Developmental delays in balance control were assessed by the Cashin Test of Motor Development (1974) and/or the Williams Gross Motor Coordination Test…

  15. Determining the optimal size for posture categories used in video-based posture assessment methods.

    Science.gov (United States)

    van Wyk, Paula M; Weir, Patricia L; Andrews, David M; Fiedler, Krysia M; Callaghan, Jack P

    2009-08-01

    Currently, there are no standards for the development of posture classification systems used in observation-based ergonomic posture assessment methods. This study was conducted to determine if an optimal posture category size for different body segments and posture views could be established by examining the trade-off between magnitude of error and the number of posture category misclassification errors made. Three groups (trunk flexion/extension and lateral bend; shoulder flexion/extension and adduction/abduction; elbow flexion/extension) of 30 participants each selected postures they perceived to correctly represent the video image shown on a computer screen. For each view, 10 images were presented for five different posture category sizes, three times each. The optimal posture category sizes established were 30 degrees for trunk, shoulder and elbow flexion/extension, 30 degrees for shoulder adduction/abduction and 15 degrees for trunk lateral bend, suggesting that posture category size should be based on the body segment and view of the image being assessed. Across all conditions, the posture category sizes were comparable to those used in published ergonomic tools.

  16. Adaptation of multi-joint balance coordination to whole body force fields

    OpenAIRE

    Engelhart, Denise; Schouten, Alfred; Aarts, Ronald; Pasma, J.; Meskers, Carel; Maier, Andrea; Kooij, van der, Marieke

    2014-01-01

    Background and aim: The ankles and the hips play an important role in standing balance. Multi-joint coordination adapts with task, the magnitude and type of disturbance [1]. Arm studies show that postural responses are highly dependent on externally applied force fields [2]. Our aim is to study how multi-joint postural responses in standing depend on such force fields, using closed loop system identification techniques (CLSIT) where two disturbances are applied [3]. This offers knowledge abou...

  17. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    2010-01-01

    Operational Experience At the end of the first full-year running period of LHC, CMS is established as a reliable, robust and mature experiment. In particular common systems and infrastructure faults accounted for <0.6 % CMS downtime during LHC pp physics. Technical operation throughout the entire year was rather smooth, the main faults requiring UXC access being sub-detector power systems and rack-cooling turbines. All such problems were corrected during scheduled technical stops, in the shadow of tunnel access needed by the LHC, or in negotiated accesses or access extensions. Nevertheless, the number of necessary accesses to the UXC averaged more than one per week and the technical stops were inevitably packed with work packages, typically 30 being executed within a few days, placing a high load on the coordination and area management teams. It is an appropriate moment for CMS Technical Coordination to thank all those in many CERN departments and in the Collaboration, who were involved in CMS techni...

  18. Emotions affect the recognition of hand postures

    Directory of Open Access Journals (Sweden)

    Carmelo Mario Vicario

    2013-12-01

    Full Text Available The body is closely tied to the processing of social and emotional information. The purpose of this study was to determine whether a relationship between emotions and social attitudes conveyed through gestures exists. Thus we tested the effect of pro-social (i.e. happy face and anti-social (i.e. angry face emotional primes on the ability to detect socially relevant handpostures (i.e. pictures depicting an open/closed hand. In particular, participants were required to establish, as quickly as possible, if the test stimulus (i.e. a hand posture was the same or different, compared to the reference stimulus (i.e. a hand posture previously displayed in the computer screen. Results show that facial primes, displayed between the reference and the test stimuli, influence the recognition of hand postures, according to the social attitude implicitly related to the stimulus. We found that perception of pro-social (i.e. happy face primes resulted in slower RTs in detecting the open hand posture as compared to the closed hand posture. Vice-versa, perception of the anti-social (i.e. angry face prime resulted in slower RTs in detecting the closed hand posture compared to the open hand posture. These results suggest that the social attitude implicitly suggested by the displayed stimuli might represent the conceptual link between emotions and gestures.

  19. Optimization of the examination posture in spinal curvature assessment

    Directory of Open Access Journals (Sweden)

    Krejci Jakub

    2012-04-01

    Full Text Available Abstract To decrease the influence of postural sway during spinal measurements, an instrumented fixation posture (called G was proposed and tested in comparison with the free standing posture (A using the DTP-3 system in a group of 70 healthy volunteers. The measurement was performed 5 times on each subject and each position was tested by a newly developed device for non-invasive spinal measurements called DTP-3 system. Changes in postural stability of the spinous processes for each subject/the whole group were evaluated by employing standard statistical tools. Posture G, when compared to posture A, reduced postural sway significantly in all spinous processes from C3 to L5 in both the mediolateral and anterioposterior directions. Posture G also significantly reduced postural sway in the vertical direction in 18 out of 22 spinous processes. Importantly, posture G did not significantly influence the spinal curvature.

  20. Optimization of the examination posture in spinal curvature assessment.

    Science.gov (United States)

    Krejci, Jakub; Gallo, Jiri; Stepanik, Petr; Salinger, Jiri

    2012-04-30

    To decrease the influence of postural sway during spinal measurements, an instrumented fixation posture (called G) was proposed and tested in comparison with the free standing posture (A) using the DTP-3 system in a group of 70 healthy volunteers. The measurement was performed 5 times on each subject and each position was tested by a newly developed device for non-invasive spinal measurements called DTP-3 system. Changes in postural stability of the spinous processes for each subject/the whole group were evaluated by employing standard statistical tools. Posture G, when compared to posture A, reduced postural sway significantly in all spinous processes from C3 to L5 in both the mediolateral and anterioposterior directions. Posture G also significantly reduced postural sway in the vertical direction in 18 out of 22 spinous processes. Importantly, posture G did not significantly influence the spinal curvature.

  1. Postural orthostatic tachycardia syndrome (POTS).

    Science.gov (United States)

    Sidhu, Bharat; Obiechina, Nonyelum; Rattu, Noman; Mitra, Shanta

    2013-09-16

    Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous group of conditions characterised by autonomic dysfunction and an exaggerated sympathetic response to assuming an upright position. Up till recently, it was largely under-recognised as a clinical entity. There is now consensus about the definition of POTS as a greater than 30/min heart rate increase on standing from a supine position (greater than 40/min increase in 12-19-year-old patients) or an absolute heart rate of greater than 120/min within 10 min of standing from a supine position and in the absence of hypotension, arrhythmias, sympathomimetic drugs or other conditions that cause tachycardia. We present two cases of POTS, followed by a discussion of its pathogenesis, pathophysiology, epidemiology and management.

  2. Reversible postural orthostatic tachycardia syndrome.

    Science.gov (United States)

    Abdulla, Aza; Rajeevan, Thirumagal

    2015-07-16

    Postural orthostatic tachycardia syndrome (POTS) is a relatively rare syndrome recognised since 1940. It is a heterogenous condition with orthostatic intolerance due to dysautonomia and is characterised by rise in heart rate above 30 bpm from base line or to more than 120 bpm within 5-10 min of standing with or without change in blood pressure which returns to base line on resuming supine position. This condition present with various disabling symptoms such as light headedness, near syncope, fatigue, nausea, vomiting, tremor, palpitations and mental clouding, etc. However there are no identifiable signs on clinical examination and patients are often diagnosed to have anxiety disorder. The condition predominantly affects young female between the ages of 15-50 but is rarely described in older people. We describe an older patient who developed POTS which recovered over 12 mo. Recognising this condition is important as there are treatment options available to alleviate the disabling symptoms.

  3. Coordination Capacity

    CERN Document Server

    Cuff, Paul; Cover, Thomas

    2009-01-01

    We develop elements of a theory of cooperation and coordination in networks. Rather than considering a communication network as a means of distributing information, or of reconstructing random processes at remote nodes, we ask what dependence can be established among the nodes given the communication constraints. Specifically, in a network with communication rates between the nodes, we ask what is the set of all achievable joint distributions p(x1, ..., xm) of actions at the nodes on the network. Several networks are solved, including arbitrarily large cascade networks. Distributed cooperation can be the solution to many problems such as distributed games, distributed control, and establishing mutual information bounds on the influence of one part of a physical system on another.

  4. [Relationship between developmental prognosis and changing picture of postural findings in early infancy among early treated children].

    Science.gov (United States)

    Yuge, M; Yamori, Y; Kanda, T; Ando, R

    1992-09-01

    We followed 93 infants prospectively who were treated because of moderate and severe grades of cerebral coordination disturbances since less than 6 months of age. They were divided into 3 groups according to developmental prognosis at 4 years of age; normal 44, mental retardation 18, and cerebral palsy 31. We compared the postural findings in supine and prone position, and 7 postural reactions at the first examination with those at discharge about 50 days after the first examination. We assessed the changing pictures of postural findings as improved, not changed or worsened. We analyzed the relationship between the changing pictures of postural findings during the short period in early infancy and the developmental prognosis among the 3 groups. The normal group showed improvement in a larger number of items than the other two groups. The findings of cerebral palsied children showed poor improvement, and more postural reactions changed to be more pathologic than those in the other two groups. Among the cerebral palsied children, ambulatory cases showed better improvement than those who could not crawl. But we found no significant difference between ambulatory and crawling children. This study demonstrated that assessment of changing pictures of postural findings in early infancy was helpful to predict developmental prognosis.

  5. Physics-based Simulation of Human Posture Using 3D Whole Body Scanning Technology for Astronaut Space Suit Evaluation

    Science.gov (United States)

    Kim, Kyu-Jung

    2005-01-01

    Over the past few years high precision three-dimensional (3D) full body laser scanners have been developed to be used as a powerful anthropometry tool for quantification of the morphology of the human body. The full body scanner can quickly extract body characteristics in non-contact fashion. It is required for the Anthropometry and Biomechanics Facility (ABF) to have capabilities for kinematics simulation of a digital human at various postures whereas the laser scanner only allows capturing a single static posture at each time. During this summer fellowship period a theoretical study has been conducted to estimate an arbitrary posture with a series of example postures through finite element (FE) approximation and found that four-point isoparametric FE approximation would result in reasonable maximum position errors less than 5%. Subsequent pilot scan experiments demonstrated that a bead marker with a nominal size of 6 mm could be used as a marker for digitizing 3-D coordinates of anatomical landmarks for further kinematic analysis. Two sessions of human subject testing were conducted for reconstruction of an arbitrary postures from a set of example postures for each joint motion for the forearm/hand complex and the whole upper extremity.

  6. 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).

  7. The Effect of Training on Postural Control in Dyslexic Children

    OpenAIRE

    Nathalie Goulème; Christophe-Loïc Gérard; Maria Pia Bucci

    2015-01-01

    The aim of this study was to explore whether a short postural training period could affect postural stability in dyslexic children. Postural performances were evaluated using Multitest Equilibre from Framiral. Posture was recorded in three different viewing conditions (eyes open fixating a target, eyes closed and eyes open with perturbed vision) and in two different postural conditions (on stable and unstable support). Two groups of dyslexic children participated in the study, i.e. G1: 16 dys...

  8. Body Posture: Functional and Structural Aspects for Health Promotion

    OpenAIRE

    Bertolini, Sonia Maria Marques Gomes; UNICESUMAR; Melocra, Polyana; Universidade Estadual de Maringá; de Paula, Karla Pereira; UNICESUMAR

    2015-01-01

    Current study comprises a bibliographical review on body posture, its implication and occupational functions. The bibliographical review was undertaken from scientific articles published between 2000 and 2012 and retrieved from Lilacs, Medline, Scielo and PubMed sites. The descriptor terms posture, anthropology, postural and body equilibrium were used. Posture is directly related to body equilibrium and both have a great importance in movement. Body posture is affected by several factors in t...

  9. Assessing the Emerging US Military Basing Posture in the Mideast

    Science.gov (United States)

    2010-02-01

    will continue to adapt its global posture to promote constructive bilateral relations, mitigate anti-access threats and off set potential political...Defense Posture in the Mideast Per Andrew Krepinevich and Robert Work, the 2004 Global Defense Posture Review began shifting the US basing posture ...Santa Monica, CA: RAND Corporation, 2007. Henry, Ryan. "Transforming the U.S. Global Defense Posture ." Naval War College Review, Spring 2006: 13-28

  10. Neutral lumbar spine sitting posture in pain-free subjects

    OpenAIRE

    O'Sullivan, Kieran; O'Dea, Patrick; Dankaerts, Wim; O'Sullivan, Peter; Clifford, Amanda; O'Sullivan, Leonard

    2010-01-01

    Sitting is a common aggravating factor in low back pain (LBP), and re-education of sitting posture is a common aspect of LBP management. However, there is debate regarding what is an optimal sitting posture. This pilot study had 2 aims; to investigate whether pain-free subjects can be reliably positioned in a neutral sitting posture (slight lumbar lordosis and relaxed thorax); and to compare perceptions of neutral sitting posture to habitual sitting posture (HSP). The lower lumbar spine HSP o...

  11. 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....

  12. Trunk coordination in dancers and nondancers.

    Science.gov (United States)

    Jarvis, Danielle N; Smith, Jo Armour; Kulig, Kornelia

    2014-08-01

    Variability, or how a task changes across trials, may reveal differences between athletes of differing skill levels. The purpose of this study was to examine trunk and lower extremity (LE) single joint kinematic variability and intersegmental coordination variability in dancers and nondancers during bipedal vertical dance jumps (sautés). Twenty healthy females, 10 with no formal dance training and 10 professional dancers, performed 20 consecutive sautés. Single joint kinematic variability was assessed using mean standard deviation of angular displacement, and intersegmental coordination variability was assessed using angular deviation of the coupling angle between segments. Within the context of the standard error of measure, there was no difference in single joint kinematic variability between dancers and nondancers. Intersegmental coordination variability in the trunk was higher than variability in LE couplings for both groups. Dancers had lower intersegmental coordination variability than nondancers for LE sagittal, frontal, and transverse plane couplings, and sagittal plane trunk couplings. Trunk adjustments may be important for successful performance, but lower intersegmental coordination variability in expert dancers indicates a higher level of control. Trunk coordination and postural control may be important factors to investigate in skilled athletes.

  13. Cataleptic postures in thalamic hemorrhage: case report

    Directory of Open Access Journals (Sweden)

    Saposnik Gustavo

    2001-01-01

    Full Text Available We report a case of catalepsy associated with thalamic hemorrhage. A 72 year-old hypertensive woman had acute onset of right-sided weakness and speech disturbances. She was on anticoagulants because of aortic valve replacement. When postures were imposed, the patient maintained the left upper limb raised for several minutes, even in uncomfortable or bizarre positions. A CT scan of the head revealed a left thalamic hemorrhage. Cataleptic postures have been reported in few cases with acute stroke.

  14. RUN COORDINATION

    CERN Multimedia

    C. Delaere

    2013-01-01

    Since the LHC ceased operations in February, a lot has been going on at Point 5, and Run Coordination continues to monitor closely the advance of maintenance and upgrade activities. In the last months, the Pixel detector was extracted and is now stored in the pixel lab in SX5; the beam pipe has been removed and ME1/1 removal has started. We regained access to the vactank and some work on the RBX of HB has started. Since mid-June, electricity and cooling are back in S1 and S2, allowing us to turn equipment back on, at least during the day. 24/7 shifts are not foreseen in the next weeks, and safety tours are mandatory to keep equipment on overnight, but re-commissioning activities are slowly being resumed. Given the (slight) delays accumulated in LS1, it was decided to merge the two global runs initially foreseen into a single exercise during the week of 4 November 2013. The aim of the global run is to check that we can run (parts of) CMS after several months switched off, with the new VME PCs installed, th...

  15. RUN COORDINATION

    CERN Multimedia

    Christophe Delaere

    2013-01-01

    The focus of Run Coordination during LS1 is to monitor closely the advance of maintenance and upgrade activities, to smooth interactions between subsystems and to ensure that all are ready in time to resume operations in 2015 with a fully calibrated and understood detector. After electricity and cooling were restored to all equipment, at about the time of the last CMS week, recommissioning activities were resumed for all subsystems. On 7 October, DCS shifts began 24/7 to allow subsystems to remain on to facilitate operations. That culminated with the Global Run in November (GriN), which   took place as scheduled during the week of 4 November. The GriN has been the first centrally managed operation since the beginning of LS1, and involved all subdetectors but the Pixel Tracker presently in a lab upstairs. All nights were therefore dedicated to long stable runs with as many subdetectors as possible. Among the many achievements in that week, three items may be highlighted. First, the Strip...

  16. Postural and Load Distribution Asymmetries in Preschoolers

    Directory of Open Access Journals (Sweden)

    Paulysnara de Oliveira Almeida

    2016-03-01

    Full Text Available The aim of the study was to investigate the postural and load distribution symmetries in preschool children. The sample consisted of 67 preschool children with a median age of 54.00 ± 5.06 months. Postural parameters such as the horizontal alignment of the head, the acromion and Antero Superior Iliac Spines (ASIS, the angles between the acromial and ASIS, frontal, Q, knee and ankle and horizontal asymmetry of the scapula in relation to T3 were evaluated by photogrammetry. The baropodometry was used to identify the distribution of plantar pressure, while the medial arch of the foot was analyzed by photographic image. The median, standard deviation and the symmetry ratio were calculated for each parameter considered symmetry values greater than 90%. The Pearson’s or Spearman’s correlation were used between the parameters analyzed. There was asymmetric for postural and load distribution parameters for both genders and a null correlation between the symmetry of the surface and foot morphology and negative weak correlation significant between of the load foot and the front angle of the lower limb symmetries. The presence of asymmetries, postural and/or of load distribution, observed in early childhood suggest the importance of monitoring the postural and foot load parameters in the long term, preventing future postural and biomechanical alterations.

  17. PALMILHAS PROPRIOCEPTIVAS PARA O CONTROLE POSTURAL

    Directory of Open Access Journals (Sweden)

    Alessandra Madia Mantovani

    2010-12-01

    Full Text Available The postural control and balance depend of the sensory system and musculoskeletal biomechanics being the feet one of the main sensors of the sensory system. The aim were to evaluate postural control and plantar pressures before, during and after the use of proprioceptive insoles. Participated 15 subjects, age 19,62,1 years old, and body mass índex (BMI of 24,45,4 kg/m2. Postural assessment values have been measured the arrows on the spine curvature, followed by analysis of plantar pressures and measures for pedobarometricstabilometric for measuring of displacement of center of pressure before, during andafter the use of insoles. In the results we saw normal arrows post insole plantar pressureand stabilometry not statistically significant after its use. Conclued that after using these insole, was saw an adequate postural realignment, probably due to adequate muscle and posture tonedemonstrating the importance of assessing the captor podal for understanding postural disordens.

  18. Integrated postural analysis in children with haemophilia.

    Science.gov (United States)

    Boccalandro, E; Pasta, G; Mannucci, P M; Santagostino, E; Peyvandi, F; Seuser, A; Mancuso, M E; Solimeno, L P

    2014-03-01

    The maintenance of a correct posture in haemophilic boys might contribute to prevent joint bleeds, chronic pain and dysfunction. This single-centre study was aimed at evaluating whether or not postural alterations are more common in haemophilic than in non-haemophilic boys and whether they are related to the orthopaedic status. Posture and balance were investigated in boys with severe/moderate haemophilia (cases) and in age-matched non-haemophilic peers (controls). Thirty-five cases (89% with haemophilia A: 74% with severe disease) were included in the study and compared with 57 controls. Posture was evaluated on digital pictures of anterior, lateral and posterior views of the habitual standing position. Balance was examined with a portable force platform with eyes open and closed. The trajectory of the total body centre of force (CoF) displacement over the platform was computed by multiple planes obtaining different measures: sway area, velocity, acceleration and body loads. The joint status of cases was assessed with the Haemophilia Joint Health Score. Cases were more disharmonic than controls (52% vs. 26% in controls; P = 0.04), swayed significantly less and more slowly than controls (P postural disharmonies than non-haemophilic peers, hence a global evaluation of the orthopaedic status should include also balance and posture examination to identify early dysfunction and establish a tailored physical or rehabilitation programme.

  19. Postural Control in Man: The Phylogenetic Perspective

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    Albert Gramsbergen

    2005-01-01

    Full Text Available Erect posture in man is a recent affordance from an evolutionary perspective. About eight million years ago, the stock from which modern humans derived split off from the ape family, and from around sixty-thousand years ago, modern man developed. Upright gait and manipulations while standing pose intricate cybernetic problems for postural control. The trunk, having an older evolutionary history than the extremities, is innervated by medially descending motor systems and extremity muscles by the more recent, laterally descending systems. Movements obviously require concerted actions from both systems. Research in rats has demonstrated the interdependencies between postural control and the development of fluent walking. Only 15 days after birth, adult-like fluent locomotion emerges and is critically dependent upon postural development. Vesttibular deprivation induces a retardation in postural development and, consequently, a retarded development of adult-like locomotion. The cerebellum obviously has an important role in mutual adjustments in postural control and extremity movements, or, in coupling the phyiogenetic older and newer structures. In the human, the cerebellum develops partly after birth and therefore is vulnerable to adverse perinatal influences. Such vulnerability seems to justify focusing our scientific research efforts onto the development of this structure.

  20. Postural Preparation to Stepping: Coupled Center of Pressure Shifts in the Anterior-Posterior and Medio-Lateral Directions

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    Hansen Clint

    2016-12-01

    Full Text Available We explored changes in the postural preparation to stepping introduced by modifications of the initial coordinates of the center of pressure (COP. We hypothesized that the postural adjustments in the anterior-posterior direction would persist across all initial COP manipulations while the adjustments in the medio-lateral direction would be highly sensitive to the initial COP coordinate. Healthy subjects stood on a force plate, shifted the body weight to one of the initial conditions that spanned the range of COP coordinates in both directions, and initiated a single step or started to walk. No major changes were observed between the stepping and walking conditions. Changes in the initial COP coordinate in the medio-lateral direction led to scaling of the magnitude of the COP shift in that direction prior to stepping accompanied by a nearly proportional change in the COP shift in the anterior-posterior direction. Changes in the initial COP coordinate in the anterior-posterior direction led to scaling of the magnitude of the COP shift in that direction prior to stepping without consistent changes in the COP shift in the medio-lateral direction. We interpret the results as reflecting a neural organization using a small set of referent body configurations for the postural adjustments.

  1. Integration of posture and movement: contributions of Sherrington, Hess, and Bernstein.

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    Stuart, Douglas G

    2005-01-01

    Neural mechanisms that integrate posture with movement are widespread throughout the central nervous system (CNS), and they are recruited in patterns that are both task- and context-dependent. Scientists from several countries who were born in the 19th century provided essential groundwork for these modern-day concepts. Here, the focus is on three of this group with each selected for a somewhat different reason. Charles Sherrington (1857-1952) had innumerable contributions that were certainly needed in the subsequent study of posture and movement: inhibition as an active coordinative mechanism, the functional anatomy of spinal cord-muscle connectivity, and helping set the stage for modern work on the sensorimotor cortex and the corticospinal tract. Sadly, however, by not championing the work of his trainee and collaborator, Thomas Graham Brown (1882-1965), he delayed progress on two key motor control mechanisms: central programming and pattern generation. Walter Hess (1881-1973), a self-taught experimentalist, is now best known for his work on CNS coordination of autonomic (visceral) and emotional behavior. His contributions to posture and movement, however, were also far-reaching: the coordination of eye movements and integration of goal-directed and "framework" (anticipatory set) motor behavior. Nikolai Bernstein (1896-1966), the quintessence of an interdisciplinary, self-taught movement neuroscientist, made far-reaching contributions that were barely recognized by Western workers prior to the 1960s. Today, he is widely praised for showing that the CNS's hierarchy of control mechanisms for posture and movement is organized hand-in-hand with distributed and parallel processing, with all three subject to evolutionary pressures. He also made important observations, like those of several previous workers, on the goal focus of voluntary movements. The contributions of Sherrington, Hess, and Bernstein are enduring. They prompt thought on the philosophical axioms that

  2. Development of Human Posture Simulation Method for Assessing Posture Angles and Spinal Loads

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    Lu, Ming-Lun; Waters, Thomas; Werren, Dwight

    2015-01-01

    Video-based posture analysis employing a biomechanical model is gaining a growing popularity for ergonomic assessments. A human posture simulation method of estimating multiple body postural angles and spinal loads from a video record was developed to expedite ergonomic assessments. The method was evaluated by a repeated measures study design with three trunk flexion levels, two lift asymmetry levels, three viewing angles and three trial repetitions as experimental factors. The study comprised two phases evaluating the accuracy of simulating self and other people’s lifting posture via a proxy of a computer-generated humanoid. The mean values of the accuracy of simulating self and humanoid postures were 12° and 15°, respectively. The repeatability of the method for the same lifting condition was excellent (~2°). The least simulation error was associated with side viewing angle. The estimated back compressive force and moment, calculated by a three dimensional biomechanical model, exhibited a range of 5% underestimation. The posture simulation method enables researchers to simultaneously quantify body posture angles and spinal loading variables with accuracy and precision comparable to on-screen posture matching methods. PMID:26361435

  3. Visual conditions and postural directions affect postural sway variability in patients with Parkinson’s disease

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    Natalia Madalena Rinaldi

    2015-05-01

    Full Text Available Postural sway variability was evaluated in Parkinson’s disease (PD patients at different stages of disease. Twenty PD patients were grouped into two groups (unilateral, 14; bilateral, 6 according to disease severity. The results showed no significant differences in postural sway variability between the groups (p ≥ 0.05. Postural sway variability was higher in the antero-posterior direction and with the eyes closed. Significant differences between the unilateral and bilateral groups were observed in clinical tests (UPDRS, Berg Balance Scale, and retropulsion test; p ≤ 0.05, all. Postural sway variability was unaffected by disease severity, indicating that neurological mechanisms for postural control still function at advanced stages of disease. Postural sway instability appears to occur in the antero-posterior direction to compensate for the stooped posture. The eyes-closed condition during upright stance appears to be challenging for PD patients because of the associated sensory integration deficit. Finally, objective measures such as postural sway variability may be more reliable than clinical tests to evaluate changes in balance control in PD patients.

  4. Neck posture during lifting and its effect on trunk muscle activation and lumbar spine posture.

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    Hlavenka, Thomas M; Christner, Vanessa F K; Gregory, Diane E

    2017-07-01

    Neck and head posture have been found to have a significant influence on the posture of the lower spine region during lifting and both an extended/upward gaze and a flexed/downward gaze have been hypothesized to lead to increased pain and/or overuse of the neck musculature. As a result, strength training recommendations have turned to the use of a retracted neck posture as being the safer posture to assume during lifting. This study examined trunk and neck muscle activity and lumbar spine posture in seven participants while performing moderate load lifts using a retracted neck posture (chin drawn in posteriorly; recently gaining popularity among coaches, trainers, and physical therapists to reduce neck pain during lifting, and freestyle neck posture (no instructions given). The retracted neck resulted in less lumbar spine flexion and increased lumbar erector spinae, external oblique, and sternocleidomastoid activity. The retracted posture also resulted in decreased activity in the thoracic erector spinae and dorsal neck musculature. The increased trunk and sternocleidomastoid activity and decreased spine flexion observed in the seven participants of this study when lifting with a retracted neck may have the potential to help lower the risk of spine pain/injury. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Coordination of complex bimanual multijoint movements under increasing cycling frequencies: the prevalence of mirror-image and translational symmetry.

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    Li, Yong; Levin, Oron; Forner-Cordero, Arturo; Ronsse, Renaud; Swinnen, Stephan P

    2009-03-01

    The present study examined the principles underlying inter and intralimb coordination constraints during performance of bimanual elbow-wrist movements at different cycling frequencies (from 0.75 Hz to 2.50 Hz). Participants performed eight coordination tasks that consisted of a combination of in-phase (IN) and/or anti-phase (AN) coordination modes between both elbows and wrists (interlimb), with isodirectional (Iso) or non-isodirectional (NonI) coordination modes within each limb (intralimb). As expected, the principle of muscle homology (in-phase coordination), giving rise to mirror symmetrical movements with respect to the mid-sagittal plane, had a powerful influence on the quality of global coordinative behavior both between and within limbs. When this principle was violated (i.e., when the anti-phase mode was introduced in one or both joint pairs), the non-isodirectional intralimb mode exhibited a (de)stabilizing role in coordination, which became more pronounced at higher cycling frequencies. However, pattern loss with increasing cycling frequency resulted not only in convergence toward the more stable in-phase patterns with the elbows and wrists but also to the anti-phase patterns (which were associated with directional compatibility of within-limb motions). Moreover, participants generally preserved their initial mode of coordination (either in-phase or anti-phase) in the proximal joints (i.e., elbows) while shifting from anti-phase to in-phase (or vice versa) with their distal joint pair (i.e., wrists). Taken together, these findings reflect the impact of two immanent types of symmetry in bimanual coordination: mirror-image and translational symmetry.

  6. Gravitational Effects upon Locomotion Posture

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    DeWitt, John K.; Bentley, Jason R.; Edwards, W. Brent; Perusek, Gail P.; Samorezov, Sergey

    2008-01-01

    Researchers use actual microgravity (AM) during parabolic flight and simulated microgravity (SM) obtained with horizontal suspension analogs to better understand the effect of gravity upon gait. In both environments, the gravitational force is replaced by an external load (EL) that returns the subject to the treadmill. However, when compared to normal gravity (N), researchers consistently find reduced ground reaction forces (GRF) and subtle kinematic differences (Schaffner et al., 2005). On the International Space Station, the EL is applied by elastic bungees attached to a waist and shoulder harness. While bungees can provide EL approaching body weight (BW), their force-length characteristics coupled with vertical oscillations of the body during gait result in a variable load. However, during locomotion in N, the EL is consistently equal to 100% body weight. Comparisons between AM and N have shown that during running, GRF are decreased in AM (Schaffner et al, 2005). Kinematic evaluations in the past have focussed on joint range of motion rather than joint posture at specific instances of the gait cycle. The reduced GRF in microgravity may be a result of differing hip, knee, and ankle positions during contact. The purpose of this investigation was to compare joint angles of the lower extremities during walking and running in AM, SM, and N. We hypothesized that in AM and SM, joints would be more flexed at heel strike (HS), mid-stance (MS) and toe-off (TO) than in N.

  7. The degrees of freedom problem in human standing posture: collective and component dynamics.

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    Zheng Wang

    Full Text Available The experiment was setup to investigate the coordination and control of the degrees of freedom (DFs of human standing posture with particular reference to the identification of the collective and component variables. Subjects stood in 3 postural tasks: feet side by side, single left foot quiet stance and single left foot stance with body rocking at the ankle joint in the sagittal plane. All three postural tasks showed very high coherence (∼ 1 of center of pressure (COP--center of mass (COM in the low frequency range. The ankle and hip coherence was mid range (∼.5 with the tasks having different ankle/hip compensatory cophase patterns. The findings support the view that the in-phase relation of the low frequency components of the COP-COM dynamic is the collective variable in the postural tasks investigated. The motions of the individual joints (ankle, knee, hip, neck and couplings of pair wise joint synergies (e.g., ankle-hip provide a supporting cooperative role to the preservation of the collective variable in maintaining the COM within the stability region of the base of support (BOS and minimizing the amount of body motion consistent with the task constraint.

  8. Body Posture Asymmetry Differences between Children with Mild Scoliosis and Children with Unilateral Cerebral Palsy

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    Małgorzata Domagalska-Szopa

    2013-01-01

    Full Text Available Patients with unilateral cerebral palsy (CP often have impaired movement coordination, reduced between-limb synchronization, and less weight bearing on the affected side, which can affect the maintenance of an upright weight-bearing position and gait. This study evaluated whether the different postural patterns of children with unilateral CP could be statistically recognized using cluster analysis. Forty-five outpatients with unilateral CP (mean age, 9 years and 5 months and 51 able-bodied children with mild scoliosis (mean age, 9 years and 2 months were included. One observer performed moiré topography (MT examinations using a CQ Electronic System (Poland device. A weight distribution analysis on the base of support (BOS between the body sides was performed simultaneously. A force plate dynamographic platform (PDM, ZEBRIS (Germany, with FootPrint software was used for these measurements. Cluster analysis revealed three groups: Cluster 1 (, 73.96%, Cluster 2 (, 8.33%, and Cluster 3 (, 17.71%. Based on the MT parameters (extracted using a data reduction technique, three typical asymmetrical postural patterns were described: (1 the postural pattern of children with mild scoliosis (SCOL, (2 the progravitational postural pattern (PGPP, and (3 the antigravitational pattern. Patterns two and three were identified in children with unilateral CP.

  9. Motor imagery modulation of postural sway is accompanied by changes in the EMG-COP association.

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    Lemos, Thiago; Rodrigues, Erika C; Vargas, Claudia D

    2014-08-08

    Motor imagery (MI) performed in an upright stance promotes increases in postural sway without changes in usual amplitude measures of calf muscle EMG. However, postural muscle activity can also be determined from the temporal association between EMG and center of pressure (COP) displacements. In this study we investigated whether the MI modulation of postural sway is accompanied by changes in EMG-COP association. Surface EMG from the lateral gastrocnemius (LG) muscle and COP coordinates were collected from 12 subjects while they imagined themselves performing a rising on tiptoes movement via kinesthetic or visual imagery. As a control condition subjects were requested to imagine singing a song. The standard deviation of the forward-backward COP sway and the coefficient of variation of the EMG were calculated and compared across tasks. The degree of association between COP sways and LG activity was evaluated through a cross-correlation function. Kinesthetic imagery promoted a larger COP displacement than both visual and control imagery (pEMG amplitude was observed across imagery tasks (p=0.08). Crucially, we found a stronger EMG-COP association during kinesthetic imagery compared to control imagery (p=0.02), whereas the EMG-COP association in visual imagery was not different from that observed during kinesthetic or control imagery (p>0.19). In conclusion, kinesthetic imagery resulted in a higher EMG-COP temporal association. Subliminal fringe mechanisms may account for the imagery effects on muscle activity and postural sway during upright stance.

  10. Body posture asymmetry differences between children with mild scoliosis and children with unilateral cerebral palsy.

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    Domagalska-Szopa, Małgorzata; Szopa, Andrzej

    2013-01-01

    Patients with unilateral cerebral palsy (CP) often have impaired movement coordination, reduced between-limb synchronization, and less weight bearing on the affected side, which can affect the maintenance of an upright weight-bearing position and gait. This study evaluated whether the different postural patterns of children with unilateral CP could be statistically recognized using cluster analysis. Forty-five outpatients with unilateral CP (mean age, 9 years and 5 months) and 51 able-bodied children with mild scoliosis (mean age, 9 years and 2 months) were included. One observer performed moiré topography (MT) examinations using a CQ Electronic System (Poland) device. A weight distribution analysis on the base of support (BOS) between the body sides was performed simultaneously. A force plate dynamographic platform (PDM), ZEBRIS (Germany), with FootPrint software was used for these measurements. Cluster analysis revealed three groups: Cluster 1 (n = 71, 73.96%), Cluster 2 (n = 8, 8.33%), and Cluster 3 (n = 17, 17.71%). Based on the MT parameters (extracted using a data reduction technique), three typical asymmetrical postural patterns were described: (1) the postural pattern of children with mild scoliosis (SCOL), (2) the progravitational postural pattern (PGPP), and (3) the antigravitational pattern. Patterns two and three were identified in children with unilateral CP.

  11. Control of grip force and vertical posture while holding an object and being perturbed.

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    Chen, Bing; Lee, Yun-Ju; Aruin, Alexander S

    2016-11-01

    We investigated motor control perspectives of coordinating maintenance of posture and application of grip force when holding an object and being perturbed. Ten subjects stood on the force platform holding an instrumented object in their dominant hand and were exposed to an external perturbation applied to their shoulders. Task demands were manipulated by positioning a slippery cap on top of the instrumented object. Grip force applied to the object, the object acceleration and the center of pressure (COP) were recorded and analyzed during the time intervals typical for the anticipatory (APA) and compensatory (CPA) components of postural control. Onsets of grip force were seen before the onsets of the COP displacement and initiation of movements of the handheld object during the APA phase of postural control, while the onsets of maximum grip force preceded the maximum COP displacement during the CPA phase. When the task demands increased by holding a handheld object with the slippery cap, subjects tended to generate grip force earlier and of a smaller magnitude; also, the COP displacement in the APA phase was smaller as compared to holding a handheld object only. The outcome provides a foundation for future studies of maintenance of vertical posture in people with impairments of balance and grip force control when holding an object and being perturbed.

  12. Reliability of photographic posture analysis of adolescents.

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    Hazar, Zeynep; Karabicak, Gul Oznur; Tiftikci, Ugur

    2015-10-01

    [Purpose] Postural problems of adolescents needs to be evaluated accurately because they may lead to greater problems in the musculoskeletal system as they develop. Although photographic posture analysis has been frequently used, more simple and accessible methods are still needed. The purpose of this study was to investigate the inter- and intra-rater reliability of photographic posture analysis using MB-ruler software. [Subjects and Methods] Subjects were 30 adolescents (15 girls and 15 boys, mean age: 16.4±0.4 years, mean height 166.3±6.7 cm, mean weight 63.8±15.1 kg) and photographs of their habitual standing posture photographs were taken in the sagittal plane. For the evaluation of postural angles, reflective markers were placed on anatomical landmarks. For angular measurements, MB-ruler (Markus Bader- MB Software Solutions, triangular screen ruler) was used. Photographic evaluations were performed by two observers with a repetition after a week. Test-retest and inter-rater reliability evaluations were calculated using intra-class correlation coefficients (ICC). [Results] Inter-rater (ICC>0.972) and test-retest (ICC>0.774) reliability were found to be in the range of acceptable to excellent. [Conclusion] Reference angles for postural evaluation were found to be reliable and repeatable. The present method was found to be an easy and non-invasive method and it may be utilized by researchers who are in search of an alternative method for photographic postural assessments.

  13. Postural stability in children with hemiplegia estimated for three postural conditions: standing, sitting and kneeling.

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    Szopa, Andrzej; Domagalska-Szopa, Małgorzata

    2015-04-01

    Postural control deficit is one of the most important problems in children with cerebral palsy (CP). The purpose of the presented study was to compare the effects of body posture asymmetry alone (i.e., in children with mild scoliosis) with the effects of body posture impairment (i.e., in children with hemiplegia) on postural stability. Forty-five outpatients with hemiplegia and 51 children with mild scoliosis were assessed using a posturography device. The examination comprised two parts: (1) analysis of the static load distribution; and (2) a posturographic test (CoP measurements) conducted in three postural conditions: standing, sitting and kneeling. Based on the asymmetry index of the unaffected/affected body sides while standing, the children with hemiplegia were divided into two different postural patterns: a pro-gravitational postural pattern (PGPP) and an anti-gravitational postural pattern (AGPP) (Domagalska-Szopa & Szopa (2013). BioMed Research International, 2013, 462094; (2014). Therapeutics and Clinical Risk Management, 10, 113). The group of children with mild scoliosis, considered as a standard for static body weight distribution, was used as the reference group. The results of present study only partially confirmed that children with hemiplegia have increased postural instability. Strong weight distribution asymmetry was found in children with an AGPP, which induced larger lateral-medial CoP displacements compared with children with scoliosis. In children with hemiplegia, distinguishing between their postural patterns may be useful to improve the guidelines for early therapy children with an AGPP before abnormal patterns of weight-bearing asymmetry are fully established.

  14. THE INFLUENCE OF DANCE HALL ON THE POSTURE OF THE STUDENTS FROM A SCHOOL DANCE IN BENTO GONÇALVES-RS

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    Grace dos Santos Feijó

    2013-11-01

    Full Text Available INTRODUCTION: The practice of Ballroom Dance (BD meets the desires of human beings to practice regular physical activity, increase self-esteem, improve cosmetic appearance and develop skills such as coordination, laterality and rhythm. However, no previous studies assessing postural changes generated by it were found. OBJECTIVE: To study the postural effects that the BD promotes in students of a dance school in the city of Bento Gonçalves-RS, over the first three months of practice. MATERIALS AND METHODS: We evaluated the static posture in the sagital plane of 18 individuals who had never come into contact with this type of dance, divided into 2 groups (control and experimental and evaluated by photographic, both pre and post-experiment. The experiment consisted of one weekly class of BD, lasting 75 minutes each, over 3 months. RESULTS AND CONCLUSION: The results of the postural assessment showed that the practice of BD affected only in the posture of the cervical spine, causing the individual practitioners to provide additional rectified after the first three months of lessons. Regarding other aspects evaluated postural significant changes were not found after comparing the results before and after the experiment, suggesting that three months practice of BD were not sufficient to promote changes in the static posture of individuals.

  15. Motor coordination: a local hub for coordination.

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    Calabrese, Ronald L

    2014-03-31

    A local interneuron of a crayfish central pattern generator serves as a hub that integrates ascending and descending coordinating information and passes it on to a local oscillatory microcircuit to coordinate a series of segmental appendages known as swimmerets.

  16. Coupling of postural and manual tasks in expert performers.

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    Amado, A C; Palmer, C J; Hamill, J; van Emmerik, R E A

    2016-04-01

    The purpose of this study was to investigate the integration of bimanual rhythmic movements and posture in expert marching percussionists. Participants (N=11) performed three rhythmic manual tasks [1:1, 2:3, and 2:3-F (2:3 rhythm played faster at a self-selected tempo)] in one of three postures: sitting, standing on one foot, and standing on two feet. Discrete relative phase, postural time-to-contact, and coherence analysis were used to analyze the performance of the manual task, postural control, and the integration between postural and manual performance. Across all three rhythms, discrete relative phase mean and variability results showed no effects of posture on rhythmic performance. The complexity of the manual task (1:1 vs. 2:3) had no effect on postural time-to-contact. However, increasing the tempo of the manual task (2:3 vs. 2:3-F) did result in a decreased postural time-to-contact in the two-footed posture. Coherence analysis revealed that the coupling between the postural and manual task significantly decreased as a function of postural difficulty (going from a two-footed to a one-footed posture) and rhythmic complexity (1:1 vs. 2:3). Taken together, these results demonstrate that expert marching percussionists systematically decouple postural and manual fluctuations in order to preserve the performance of the rhythmic movement task.

  17. Evaluation of upper-limb body postures based on the effects of back and shoulder flexion angles on subjective discomfort ratings, heart rates and muscle activities.

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    Lim, Cheol-Min; Jung, Myung-Chul; Kong, Yong-Ku

    2011-09-01

    A possible limitation of many ergonomics checklists that evaluate postures is an independent evaluation of each body segment without considering the coordination between body segments and resulting in the under-/over-estimation of body postures. A total of 20 men were selected to evaluate the effects of shoulder and back flexion angles on the upper-limb muscle activities, subjective discomforts and heart rates. Interesting findings were obtained from the coordination between back flexion angles and shoulder flexion angles. At a back flexion angle of 45°, the discomfort and heart rates were the least at a shoulder flexion angle of 45°. The %MVC also showed a similar trend. It could be inferred that the 0° shoulder flexion angle would be a natural posture, when the back flexion angle is 0°, whereas 45° shoulder flexion might be a more natural posture when the back flexion angle is 45°. STATEMENT OF RELEVANCE: This study evaluated the effects of back and shoulder flexion angles on subjective as well as objective measures. The findings of this study considered the coordination between two body flexion angles and could be used to improve the accuracy of existing ergonomics evaluation methods for body postures.

  18. Postural sway following cryotherapy in healthy adults.

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    Fukuchi, Claudiane A; Duarte, Marcos; Stefanyshyn, Darren J

    2014-01-01

    In light of the wide use of cryotherapy and its potential negative effects on postural stability, little is known about how postural sway is affected, particularly when the whole lower limb is immersed. The purpose of this study was to analyze the influence of cryotherapy on postural sway in healthy males. Twenty-six subjects were randomly assigned into two intervention groups: control (tepid water at ∼26°C) or ice (cold water at ∼11°C). Postural sway was measured through the center of pressure (COP) position while they stood on a force plate during bipedal (70 s) and unipedal (40 s) conditions before and after the subjects were immersed in a water tub up to the umbilical level for 20 min. COP standard deviation (SD) and COP velocity were analyzed in the anterior-posterior (AP) and medial-lateral (ML) directions. Statistical analysis showed that in the bipedal condition cryotherapy increased the COP SD and COP velocity in the ML direction. During the unipedal condition, a higher COP velocity in the AP and ML directions was also reported. Our findings indicate that cryotherapy by immersing the whole lower limb should be used with caution before engaging in challenging postural control activities.

  19. The importance of recognizing postural pseudoanemia.

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    Goldner, Fred; Jacob, Giris; Raj, Satish R; Robertson, David

    2006-01-01

    The determination of the packed red cell volume and the hemoglobin level has been paramount for monitoring anemia and blood loss for patients in the hospital setting. Recently, these variables have been studied during various control conditions including changes in posture. It has been found that the hematocrit changes markedly with alteration of body posture, in such a way that shifts of estimated blood volume of 1 pint can commonly be elicited by a simple change of posture from supine to upright or vice versa. Therefore, it is important to recognize that in addition to the numerous pathological conditions that may affect the value of the packed cell volume, certain physiological maneuvers may have an equal impact and may confound the accurate assessment of true pathological changes in these variables. Thus, changes in posture can lead to substantial changes in hematocrit, which may be attributed mistakenly to blood loss or acute anemia and may result in a cascade of unnecessary diagnostic costs. In reality, these changes represent postural pseudoanemia, a normal physiological response to a change in position from standing to lying.

  20. Transfer of dynamic learning across postures.

    Science.gov (United States)

    Ahmed, Alaa A; Wolpert, Daniel M

    2009-11-01

    When learning a difficult motor task, we often decompose the task so that the control of individual body segments is practiced in isolation. But on re-composition, the combined movements can result in novel and possibly complex internal forces between the body segments that were not experienced (or did not need to be compensated for) during isolated practice. Here we investigate whether dynamics learned in isolation by one part of the body can be used by other parts of the body to immediately predict and compensate for novel forces between body segments. Subjects reached to targets while holding the handle of a robotic, force-generating manipulandum. One group of subjects was initially exposed to the novel robot dynamics while seated and was then tested in a standing position. A second group was tested in the reverse order: standing then sitting. Both groups adapted their arm dynamics to the novel environment, and this movement learning transferred between seated and standing postures and vice versa. Both groups also generated anticipatory postural adjustments when standing and exposed to the force field for several trials. In the group that had learned the dynamics while seated, the appropriate postural adjustments were observed on the very first reach on standing. These results suggest that the CNS can immediately anticipate the effect of learned movement dynamics on a novel whole-body posture. The results support the existence of separate mappings for posture and movement, which encode similar dynamics but can be adapted independently.

  1. Investigation of the Differential Contributions of Superficial and Deep Muscles on Cervical Spinal Loads with Changing Head Postures.

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    Chih-Hsiu Cheng

    Full Text Available Cervical spinal loads are predominately influenced by activities of cervical muscles. However, the coordination between deep and superficial muscles and their influence on the spinal loads is not well understood. This study aims to document the changes of cervical spinal loads and the differential contributions of superficial and deep muscles with varying head postures. Electromyography (EMG of cervical muscles from seventeen healthy adults were measured during maximal isometric exertions for lateral flexion (at 10°, 20° and terminal position as well as flexion/extension (at 10°, 20°, 30°, and terminal position neck postures. An EMG-assisted optimization approach was used to estimate the muscle forces and subsequent spinal loads. The results showed that compressive and anterior-posterior shear loads increased significantly with neck flexion. In particular, deep muscle forces increased significantly with increasing flexion. It was also determined that in all different static head postures, the deep muscle forces were greater than those of the superficial muscle forces, however, such pattern was reversed during peak efforts where greater superficial muscle forces were identified with increasing angle of inclination. In summary, the identification of significantly increased spinal loads associated with increased deep muscle activation during flexion postures, implies higher risks in predisposing the neck to occupationally related disorders. The results also explicitly supported that deep muscles play a greater role in maintaining stable head postures where superficial muscles are responsible for peak exertions and reinforcing the spinal stability at terminal head postures. This study provided quantitative data of normal cervical spinal loads and revealed motor control strategies in coordinating the superficial and deep muscles during physical tasks.

  2. Investigation of the Differential Contributions of Superficial and Deep Muscles on Cervical Spinal Loads with Changing Head Postures.

    Science.gov (United States)

    Cheng, Chih-Hsiu; Chien, Andy; Hsu, Wei-Li; Chen, Carl Pai-Chu; Cheng, Hsin-Yi Kathy

    2016-01-01

    Cervical spinal loads are predominately influenced by activities of cervical muscles. However, the coordination between deep and superficial muscles and their influence on the spinal loads is not well understood. This study aims to document the changes of cervical spinal loads and the differential contributions of superficial and deep muscles with varying head postures. Electromyography (EMG) of cervical muscles from seventeen healthy adults were measured during maximal isometric exertions for lateral flexion (at 10°, 20° and terminal position) as well as flexion/extension (at 10°, 20°, 30°, and terminal position) neck postures. An EMG-assisted optimization approach was used to estimate the muscle forces and subsequent spinal loads. The results showed that compressive and anterior-posterior shear loads increased significantly with neck flexion. In particular, deep muscle forces increased significantly with increasing flexion. It was also determined that in all different static head postures, the deep muscle forces were greater than those of the superficial muscle forces, however, such pattern was reversed during peak efforts where greater superficial muscle forces were identified with increasing angle of inclination. In summary, the identification of significantly increased spinal loads associated with increased deep muscle activation during flexion postures, implies higher risks in predisposing the neck to occupationally related disorders. The results also explicitly supported that deep muscles play a greater role in maintaining stable head postures where superficial muscles are responsible for peak exertions and reinforcing the spinal stability at terminal head postures. This study provided quantitative data of normal cervical spinal loads and revealed motor control strategies in coordinating the superficial and deep muscles during physical tasks.

  3. Coordinate systems for the carpal bones of the wrist.

    Science.gov (United States)

    Coburn, James C; Upal, Mohammad A; Crisco, Joseph J

    2007-01-01

    The eight small and complexly shaped carpal bones of the wrist articulate in six degrees of freedom with each other and to some extent with the radius and the metacarpals. With the increasing number and sophistication of studies of the carpus, a standardized definition for a coordinate system for each the carpal bones would aid in the reporting and comparison of findings. This paper presents a method for defining and constructing a coordinate system specific to each of the eight carpal bones based upon the inertial properties of the bone, derived from surface models constructed from three-dimensional (3-D) medical image volumes. Surface models from both wrists of 5 male and 5 female subjects were generated from CT image volumes in two neutral wrist positions (functional and clinical). An automated algorithm found the principal inertial axes and oriented them according to preset conditions in 85% of the bones, the remaining bones were corrected manually. Six of the eight carpal bones were significantly more extended in the functional neutral position than in the clinical neutral position. Gender had no significant effect on carpal bone posture in either wrist position. Correlations between the 3-D carpal posture and the commonly used 2-D clinical radiographic carpal angles are established. 3-D coordinate systems defined by the anatomy of the carpal bone, such as the ones presented here, are necessary to completely describe 3-D changes in the posture of the carpal bones.

  4. 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.

  5. IMPLICATIONS OF MOUTH BREATHING AND ATYPICAL SWALLOWING IN BODY POSTURE

    National Research Council Canada - National Science Library

    Veronique Sousa; Maria Paço; Teresa Pinho

    2017-01-01

    .... Changes in any of the parts may lead to a general postural imbalance. Purpose: To verify if there is a relation between breathing pattern and swallowing with posture, dental occlusion and harmful oral habits of the sample under study...

  6. Good Posture--An Aid to Learning and Health.

    Science.gov (United States)

    Marciante, Robert E.

    1983-01-01

    Emphasizes the importance of promoting children's good health and proper posture through encouragement and the efforts of parents, physical education teachers, and classroom instructors. Outlines precise roles and responsibilities of each in improving children's posture. (DMM)

  7. Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures

    Directory of Open Access Journals (Sweden)

    Han Suk Lee

    2015-01-01

    Full Text Available Objective. To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP. Methods. In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation and calculated the root mean square error in trials for each subject. Spearman’s rank correlation coefficients and regression analysis were used to assess the degree of correlation between the trunk posture and HRA value, and a significance level of α = 0.05 was considered. Results. There were significant correlations between the HRA value of right side neck flexion and pelvic side tilt angle (p<0.05. If pelvic side tilting angle increases by 1 degree, right side neck flexion increased by 0.76 degrees (p=0.026. However, there were no significant correlations between other neck motions and trunk postures. Conclusion. Verifying pelvic postures should be prioritized when movement is limited due to the vitiation of the proprioceptive sense of neck caused by FHP.

  8. Fingertip contact influences human postural control

    Science.gov (United States)

    Jeka, J. J.; Lackner, J. R.

    1994-01-01

    Touch and pressure stimulation of the body surface can strongly influence apparent body orientation, as well as the maintenance of upright posture during quiet stance. In the present study, we investigated the relationship between postural sway and contact forces at the fingertip while subjects touched a rigid metal bar. Subjects were tested in the tandem Romberg stance with eyes open or closed under three conditions of fingertip contact: no contact, touch contact (postural sway when compared to the no contact, eyes closed condition. Body sway and fingertip forces were essentially in phase with force contact, suggesting that fingertip contact forces are physically counteracting body sway. Time delays between body sway and fingertip forces were much larger with light touch contact, suggesting that the fingertip is providing information that allows anticipatory innervation of musculature to reduce body sway. The results are related to observations on precision grip as well as the somatosensory, proprioceptive, and motor mechanisms involved in the reduction of body sway.

  9. Postural stability in young and old women

    DEFF Research Database (Denmark)

    Jørgensen, Martin Grønbech

    , National Institute of Health, Bethesda, MD, USA; 3Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense   INTRODUCTION: Poor postural balance control (stability) is one of the major risk factors for falling. If individuals at risk of falling are to be identified...... effectively demonstrate differences in postural balance control between physically active old and young women.......USE OF VARIABILITY, SPEED AND ACCELERATION PARAMETERS TO EVALUATE POSTURAL BALANCE IN OLD VS YOUNG INDIVIDUALS   Jørgensen MG1,3, Larsen AH3, Caserotti P2,3, Nielsen OBF1, Aagaard P3   1Geriatric Department and Fall Clinic, Aarhus University Hospital, Aalborg Hospital; 2National Institute on Aging...

  10. Impaired postural stability after laparoscopic surgery

    DEFF Research Database (Denmark)

    Eskildsen, K Z; Staehr-Rye, A K; Rasmussen, L S;

    2015-01-01

    BACKGROUND: Early postoperative mobilisation may reduce patient morbidity and improve hospital efficiency by accelerated discharge. The aim of this study was to measure postural stability early after laparoscopic surgery in order to assess how early it is safe to mobilise and discharge patients....... METHODS: We included 25 women undergoing outpatient gynaecological laparoscopic surgery in the study. Patients received standardised anaesthesia with propofol, remifentanil and rocuronium. Postural stability was assessed preoperatively, at 30 min after tracheal extubation, and at discharge from the post...... postoperatively. No significant changes were found for sway velocity. We found no significant changes in mean sway, sway area or sway velocity at discharge from the post-anaesthesia care unit approximately 2 h after surgery. CONCLUSION: Postural stability was significantly impaired 30 min after outpatient...

  11. Falls study: Proprioception, postural stability, and slips.

    Science.gov (United States)

    Sohn, Jeehoon; Kim, Sukwon

    2015-01-01

    The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls.

  12. Smart garment to help children improve posture.

    Science.gov (United States)

    Lou, E; Moreau, M J; Hill, D L; Raso, V J; Mahood, J K

    2006-01-01

    Many of the aches and pains of adults are the result not of injuries, but of the long-term effects of distortions in posture or alignment. Postural kyphosis in adolescence may be one of the effects of poor standing and sitting habits. Kyphosis is an excessive rounding of the upper spine. A smart garment that can monitor and provide vibration feedback to children has been developed to investigate an alternative treatment possibility. Laboratory tests verified that the accuracy of the system was +/-2 degrees within the full 180 degrees range. A clinical trial has been conducted and it showed that the system can aid subjects to improve by 20% the proportion of time in a more balanced posture. The long term effect is still under investigation.

  13. Postural balance in low back pain patients

    DEFF Research Database (Denmark)

    Maribo, Thomas; Stengaard-Pedersen, Kristian; Jensen, Lone Donbæk

    2011-01-01

    Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (Co...... Ratio) might be of clinical interest. This study aimed to assess postural balance in LBP patients by analyzing intra-session reliability of CoP parameters on a portable force platform, the Romberg Ratio, and the OLST. Furthermore, we aimed to determine whether CoP parameters and OLST measure identical...... aspects of postural stability. We examined 49 LBP patients and found acceptable reliability of the CoP parameters’ trace length and velocity, whereas reliability regarding C90 area, the Romberg Ratio, and the OLST was poor. Correlations between the CoP parameters and OLST were insignificant. Reliability...

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

    Science.gov (United States)

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

    2017-02-06

    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

  15. POSTURAL DISTURBANCES AND FEET DEFORMITIES IN CHILDREN WITH CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    V. M. Kenis

    2011-01-01

    Full Text Available The purpose of study was to estimate common postural disturbances in children with cerebral palsy in relation to feet deformities. 100 children were investigated. Age-related changes in postural patterns are described. Five stereotypical postural patterns are most common in children with cerebral palsy. Proper management of feet deformities is necessary for correction of postural disturbance. Inadequate surgical treatment, as a contrast, may be harmfull and dangerous.

  16. POSTURAL DISTURBANCES AND FEET DEFORMITIES IN CHILDREN WITH CEREBRAL PALSY

    OpenAIRE

    V. M. Kenis; Ivanov, S V; Yu. A. Stepanova

    2011-01-01

    The purpose of study was to estimate common postural disturbances in children with cerebral palsy in relation to feet deformities. 100 children were investigated. Age-related changes in postural patterns are described. Five stereotypical postural patterns are most common in children with cerebral palsy. Proper management of feet deformities is necessary for correction of postural disturbance. Inadequate surgical treatment, as a contrast, may be harmfull and dangerous.

  17. Trunk muscle activity with different sitting postures and pelvic inclination

    OpenAIRE

    WATANABE, MASAHIRO; Kaneoka, Koji; Wada, Yusuke; Matsui, Yasushi; Miyakawa, Shumpei

    2014-01-01

    BACKGROUND AND OBJECTIVE: Sitting posture may often place large burden on trunk muscles, while trunk muscle activities in the sitting posture have not been well clarified. In this study, a difference in trunk muscle activity between two kinds of sitting postures was evaluated, focusing on low back pain induced by posture holding.MATERIAL AND METHODS: An experiment was conducted on the subjects sitting on a stable-seat and on an unstable-seat, with the pelvis inclined forward, backward, rightw...

  18. Smart garment for trunk posture monitoring: A preliminary study

    OpenAIRE

    2008-01-01

    Abstract Background Poor postures of the spine have been considered in association with a number of spinal musculoskeletal disorders, including structural deformity of the spine and back pain. Improper posturing for the patients with spinal disorders may further deteriorate their pain and deformities. Therefore, posture training has been proposed and its rationale is to use the patient's own back muscles to keep the spine within the natural curvature. A posture training device may help to fac...

  19. Postural control in strabismic children: importance of proprioceptive information

    OpenAIRE

    Lions, Cynthia; Bui Quoc, Emmanuel; Wiener-Vacher, Sylvette; Bucci, Maria P.

    2014-01-01

    Objective: To examine the effect of proprioceptive information during postural control in strabismic children. Methods: Postural stability was recorded with a platform (Techno Concept®) in 12 strabismic children aged from 4.9 to 10 years and data were compared to that of 12 control age-matched children. Two postural positions were performed: Romberg and Tandem. Two postural conditions: without and with foam pad. We analyzed the surface area, the length, the mean speed of the center of pres...

  20. Reliability of upright posture measurements in primary school children

    OpenAIRE

    Grimmer Karen; McEvoy Maureen P

    2005-01-01

    Abstract Background Correct upright posture is considered to be a measure of good musculoskeletal health. Little is known about the usual variability of children's upright standing posture. The aim of this study was to assess differences between repeated measures of upright posture in a group of primary school children. Methods Sagittal plane photographs of usual, relaxed upright standing posture of 38 boys and girls aged 5–12 years were taken twice within an hour. Reflective markers were pla...

  1. Smart garment for trunk posture monitoring: A preliminary study

    OpenAIRE

    Wong Man; Wong Wai

    2008-01-01

    Abstract Background Poor postures of the spine have been considered in association with a number of spinal musculoskeletal disorders, including structural deformity of the spine and back pain. Improper posturing for the patients with spinal disorders may further deteriorate their pain and deformities. Therefore, posture training has been proposed and its rationale is to use the patient's own back muscles to keep the spine within the natural curvature. A posture training device may help to fac...

  2. Remarks on human body posture estimation from silhouette image based on heuristic rules and Kalman filter

    Science.gov (United States)

    Takahashi, Kazuhiko; Naemura, Masahide

    2005-12-01

    This paper proposes a human body posture estimation method based on analysis of human silhouette and Kalman filter. The proposed method is based on both the heuristically extraction method of estimating the significant points of human body and the contour analysis of the human silhouette. The 2D coordinates of the human body's significant points, such as top of the head, and tips of feet, are located by applying the heuristically extraction method to the human silhouette, those of tips of hands are obtained by using the result of the contour analysis, and the joints of elbows and knees are estimated by introducing some heuristic rules to the contour image of the human silhouette. The estimated results are optimized and tracked by using Kalman filter. The proposed estimation method is implemented on a personal computer and runs in real-time. Experimental results show both the feasibility and the effectiveness of the proposed method for estimating human body postures.

  3. Delayed postural control during self-generated perturbations in the frail older adults

    Directory of Open Access Journals (Sweden)

    Kubicki A

    2012-02-01

    Full Text Available Alexandre Kubicki1–3, François Bonnetblanc1,2, Geoffroy Petrement3, Yves Ballay1,2, France Mourey2,4¹UFR STAPS, Université de Bourgogne, Dijon, France; ²Motricité et Plasticité, Institut National de la Santé et de la Recherche Médicale (INSERM, Dijon, France; ³SARL Fovea Interactive, Campus Industriel – Espace Entreprises, Chalon sur Saône, France; 4UFR Médecine, Université de Bourgogne, Dijon, FrancePurpose: The aim of this study was to investigate the coordination between posture and movement in pathological aging (frailty in comparison with normal aging, with the hypothesis that in pathological aging, postural control evolves towards a more reactive mode for which the perturbation induced by the movement is not anticipated and leads to delayed and late postural adjustments.Methods: Elderly subjects performed rapid focal arm-raising movements towards a target, from an upright standing position in two stimuli conditions: simple reaction time and choice reaction time (CRT. Hand and center of pressure (CoP kinematics were compared between a control group and a frail group of the same age.Results: In frail individuals, the entire movement was impaired and slowed down. In addition, postural adjustments that classically precede and accompany the focal arm movement were delayed and reduced, especially in the CRT condition in which the motor prediction is more limited. Finally, a correlation between the time to CoP maximal velocity and the timed up-and-go score was observed.Conclusion: In these patients, it was concluded that the control of the CoP displacement evolved from a proactive mode in which the perturbation associated with the arm movement is anticipated toward a more reactive mode in which the perturbation is compensated by late and delayed adjustments.Keywords: frailty, anticipatory postural adjustments, backward disequilibrium

  4. Postural reactions of girls and boys aged 12–15 years evaluated using the Romberg test

    Directory of Open Access Journals (Sweden)

    Jacek Wilczyński

    2016-07-01

    Full Text Available Introduction : The complex system controlling human posture includes a gaze stabilisation system, which comprises the control of direction and visual acuity during head and body movements, and a posture stabilisation system, keeping the body in balance at rest and in movement. Aim of the research: To analyse the postural reaction of SOX and SOY using the Romberg test with eyes open (EO and closed (CE in girls and boys aged 12–15 years. Material and methods : The study included 503 students of Primary School No. 13 and School No. 4 in Starachowice. Postural reactions were tested on a Cosmogamma platform by Emildue R50300. Postural reactions were analysed, and mean sway X (MSX and mean sway Y (MSY were calculated. Results: Analysis of variance showed significant differences of MSX only between girls and boys (p < 0.036. MSX was significantly lower in girls in both tests with EO and CE. Although there was no apparent significant difference of MSX between the Romberg test with EO and CE, a slight progression was observed in the test with CE. Analysis of variance of MSY with a single classification showed a significant effect of study options (p < 0.048, a significant interaction of gender and options of the study (p < 0.048, and a significant interaction of age and options of the study (p < 0.026. Analysis of variance of MSY showed a significant progression of MSY in the test with CE. Conclusions : Our research showed that balance with CE does not worsen, so it can be assumed that children have limited skills of using vision to maintain balance because there is a lack of appropriate coordination between vision and motor abilities, which in children are in development.

  5. 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...

  6. Human Posture Estimation using Visual Information

    Institute of Scientific and Technical Information of China (English)

    Jiayu XU

    2014-01-01

    Human-robot cooperation is one of the central research issues in robotics.Al kinds of sensors wil be used since the robot should understand human’s intention.This article wil focus on the human posture estimation by using Microsoft Kinect.The visual Information from Kinect can be acquired and used to extract the human skeletal information and further,calcu-late the human posture.The experiment results have been compared with a Qualisys system,which has been proved quite precisely.

  7. Postural balance in low back pain patients

    DEFF Research Database (Denmark)

    Maribo, Thomas; Stengaard-Pedersen, Kristian; Jensen, Lone Donbæk

    2011-01-01

    Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (Co...... Ratio) might be of clinical interest. This study aimed to assess postural balance in LBP patients by analyzing intra-session reliability of CoP parameters on a portable force platform, the Romberg Ratio, and the OLST. Furthermore, we aimed to determine whether CoP parameters and OLST measure identical...

  8. Strategic political postures and political market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Henneberg, Stephan C.

    2010-01-01

    Recently, the areas of strategic political marketing and political market orientation have been the subject of several conceptual articles which have provided the theoretical foundations for further empirical work. However, despite the close conceptual relatedness of the proposed concepts...... by developing an integrated concept of political marketing strategy using two complementary frameworks, namely Strategic Political Postures (SPP) and Political Market Orientation (PMO). We introduce the two main concepts and derive for each of the strategic posture-specific PMO profiles as well as inter...

  9. 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…

  10. An OWAS-based analysis of nurses' working postures.

    Science.gov (United States)

    Engels, J A; Landeweerd, J A; Kant, Y

    1994-05-01

    The working postures of Dutch nurses (n = 18) in an orthopaedic ward and a urology ward were observed using the Ovako Working posture Analysis System (OWAS). During observation, both working postures and activities were recorded. A specially developed computer program was used for data analysis. By means of this program, it was possible to calculate the working posture load for each activity and the contribution of a specific activity to the total working posture load. This study shows that some activities of the nurses in both wards were performed with poor working postures. In the orthopaedic (resp. urology) ward two (resp. one) out of 19 observed postures of parts of the body were classified as Action Category 2. Moreover, 20% (resp. 16%) of the so-called typical working postures was classified in Action Category 2. This suggests, that in both wards working postures that are slightly harmful to the musculoskeletal system, occur during a substantial part of the working day. Differences between both wards with respect to working posture load and time expenditure were determined. Activities causing the workload to fall into OWAS higher Action Categories were identified. The data show that poor working postures in the nursing profession not only occur during patient handling activities but also during tasks like 'administration'. Focusing on patient-handling (i.e., lifting patients) in order to determine the load on the musculoskeletal system would therefore lead to an underestimation of the total working posture load of nurses.

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

    Science.gov (United States)

    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 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.

  12. Pseudodystonic Posture Secondary to Klippel–Feil Syndrome and Diastematomyelia

    Science.gov (United States)

    Lopez-Vicchi, Martin; Da Prat, Gustavo; Gatto, Emilia Mabel

    2015-01-01

    Background Dystonic postures possess a great number of differential diagnoses. Phenomenology Shown We describe a pseudodystonic posture in a 61-year-old woman with skeletal and extra-skeletal abnormalities. Educational Value Klippel–Feil syndrome represents an unusual cause of pseudodystonic posture to be considered in the differential diagnosis of dystonia. PMID:27352284

  13. Adaptive postural control for joint immobilization during multitask performance.

    Directory of Open Access Journals (Sweden)

    Wei-Li Hsu

    Full Text Available Motor abundance is an essential feature of adaptive control. The range of joint combinations enabled by motor abundance provides the body with the necessary freedom to adopt different positions, configurations, and movements that allow for exploratory postural behavior. This study investigated the adaptation of postural control to joint immobilization during multi-task performance. Twelve healthy volunteers (6 males and 6 females; 21-29 yr without any known neurological deficits, musculoskeletal conditions, or balance disorders participated in this study. The participants executed a targeting task, alone or combined with a ball-balancing task, while standing with free or restricted joint motions. The effects of joint configuration variability on center of mass (COM stability were examined using uncontrolled manifold (UCM analysis. The UCM method separates joint variability into two components: the first is consistent with the use of motor abundance, which does not affect COM position (VUCM; the second leads to COM position variability (VORT. The analysis showed that joints were coordinated such that their variability had a minimal effect on COM position. However, the component of joint variability that reflects the use of motor abundance to stabilize COM (VUCM was significant decreased when the participants performed the combined task with immobilized joints. The component of joint variability that leads to COM variability (VORT tended to increase with a reduction in joint degrees of freedom. The results suggested that joint immobilization increases the difficulty of stabilizing COM when multiple tasks are performed simultaneously. These findings are important for developing rehabilitation approaches for patients with limited joint movements.

  14. Limitations of Radar Coordinates

    OpenAIRE

    Bini, Donato; Lusanna, Luca; Mashhoon, Bahram

    2004-01-01

    The construction of a radar coordinate system about the world line of an observer is discussed. Radar coordinates for a hyperbolic observer as well as a uniformly rotating observer are described in detail. The utility of the notion of radar distance and the admissibility of radar coordinates are investigated. Our results provide a critical assessment of the physical significance of radar coordinates.

  15. Adaptation of multi-joint balance coordination to whole body force fields

    NARCIS (Netherlands)

    Engelhart, Denise; Schouten, Alfred; Aarts, Ronald; Pasma, J.; Meskers, Carel; Maier, Andrea; Kooij, van der Herman

    2014-01-01

    Background and aim: The ankles and the hips play an important role in standing balance. Multi-joint coordination adapts with task, the magnitude and type of disturbance [1]. Arm studies show that postural responses are highly dependent on externally applied force fields [2]. Our aim is to study how

  16. Posture and Texting: Effect on Balance in Young Adults.

    Directory of Open Access Journals (Sweden)

    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.

  17. Public and Private Posture : Zadie Smith

    NARCIS (Netherlands)

    Heynders, Odile

    2016-01-01

    This chapter will focus on Smith’s posture, and in particular on how her public position and literary work negotiate issues such as identification, celebrity, style and authenticity. First, the paradox of the ‘celebrity authority’ will be examined, followed by a Derrida-inspired analysis of Smith’s

  18. Can Smartwatches Replace Smartphones for Posture Tracking?

    Directory of Open Access Journals (Sweden)

    Bobak Mortazavi

    2015-10-01

    Full Text Available 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.

  19. 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.

  20. Evaluation of postural mechanisms under dynamic conditions

    Science.gov (United States)

    Anderson, D. J.

    1978-01-01

    A stimulus delivery and data acquisition system for assessment of human posture was developed based on a digital computer and a translating platform. The movement of the platform acts to displace the subject's base of support while the computer tracks the corrections which are made by the subject to maintain balance. Various stimuli are used ranging from fast transients to sine waves.

  1. 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).

  2. [Maternal postures and epidural analgesia during labour].

    Science.gov (United States)

    Ducloy-Bouthors, A-S; De Gasquet, B; Davette, M; Cuisse, M

    2006-06-01

    The evolution of birth is of interest for obstetricians and midwives. Postures with asymmetric stretching and balance, kneeling, or sitting have been claimed to be able to help foetal head rotation. Although walking during labour have no influence on the outcome of labour, hip-flexed postures enlarging the pelvic diameter are yet evaluated to improve the obstetric course of labour. In a prospective randomised study including 93 parturients, we compared the supine 30 degrees lateral tilt (control group) to three hip-flexed postures: sitting (S), right hip-flexed left lateral position (L) and left hip-flexed right lateral position (R). Epidural analgesia with 12 ml ropivacaine 0.1% and sufentanil 0.5 microg/ml was administered over a period of six minutes. The total epidural spread was 15+/-0.3 dermatomes and the upper level of thermo-analgesic blockade reached T7-T8 (T5 to T10) in each group. There were no differences between groups for the left and right total spread and upper level of epidural blockade, for the time to maximal block and pain relief. There was no motor block and no maternal or foetal side effects. We conclude that, for the three hip-flexed postures tested, position does not influence local anesthetic spread or symmetry of analgesia after induction of obstetric epidural anaesthesia.

  3. Robust balance shift control with posture optimization

    NARCIS (Netherlands)

    Kavafoglu, Z.; Kavafoglu, Ersan; Egges, J.

    2015-01-01

    In this paper we present a control framework which creates robust and natural balance shifting behaviours during standing. Given high-level features such as the position of the center of mass projection and the foot configurations, a kinematic posture satisfying these features is synthesized using o

  4. Evaluation of body posture in nursing students.

    Science.gov (United States)

    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 (pvalores 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.

  5. 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.

  6. Posture and the circulation: the age effect.

    Science.gov (United States)

    Smith, J J; Porth, C J

    1991-01-01

    The primary instigator of circulatory response to the upright posture is the rapid displacement of about 10% of blood volume from the thorax to the lower body. The resultant hemodynamic deficit induces postural intolerance, especially orthostatic hypotension, in elderly over 70 years of age and in some young subjects after exposure to weightlessness. In this review, our objectives have been: 1) to describe in the normal subject the hemodynamic consequences of the headup posture, as well as lower body negative pressure, the compensatory responses intended to cope with these stresses, and their mechanisms; 2) to outline the effect of age on the circulatory responses to these stresses; and (3) to analyze and compare the tests currently used to assess circulatory tolerance. Our ability to design effective countermeasures to orthostatic circulatory intolerance is severely handicapped by our inadequate knowledge of the basic hemodynamic events incident to normal and abnormal orthostatic tolerance. We believe that better understanding and standardization of the postural tests, better experimental design to include greater emphasis on inter and intra-individual variability, and wider application of currently available noninvasive circulatory techniques would greatly improve the prospects for success in this research area.

  7. Postural stability assessment in sewer workers.

    Science.gov (United States)

    Kuo, W; Bhattacharya, A; Succop, P; Linz, D

    1996-01-01

    In this study, postural stability was measured with a microcomputer-based force platform as an indirect assessment of central nervous system effect in 28 sewer workers (age range 23.4 to 64.5 years, standard deviation of 8.7 years). All workers performed four 30-second postural sway tests. The organic-solvent exposure was measured by a photo-ionization detector. The photo-ionization detector was calibrated to measure volatile organic solvents in total benzene equivalence, and concentrations were measured in various parts of the plant. The mean exposure was .32 parts per million (ppm) benzene equivalent (range of .02 to .95 ppm, standard deviation .19 ppm). Based on a covariate adjusted linear multiple-regression model, a statistically significant (p organic-solvent exposure. These workers also had increased postural sway compared with a nonexposed population. The statistically significant correlation between postural sway determinations and organic-solvent exposure was surprising given the very low exposures measured. It is possible that the organic-solvent exposure might not be the causative agent, but rather that the solvents themselves correlate with some other causative exposure, ie, total volatile organics as implicated in the cause of sick-building syndrome.

  8. Postural orthostatic tachycardia syndrome: a clinical review.

    Science.gov (United States)

    Johnson, Jonathan N; Mack, Kenneth J; Kuntz, Nancy L; Brands, Chad K; Porter, Coburn J; Fischer, Philip R

    2010-02-01

    Postural orthostatic tachycardia syndrome was defined in adult patients as an increase >30 beats per minute in heart rate of a symptomatic patient when moving from supine to upright position. Clinical signs may include postural tachycardia, headache, abdominal discomfort, dizziness/presyncope, nausea, and fatigue. The most common adolescent presentation involves teenagers within 1-3 years of their growth spurt who, after a period of inactivity from illness or injury, cannot return to normal activity levels because of symptoms induced by upright posture. Postural orthostatic tachycardia syndrome is complex and likely has numerous, concurrent pathophysiologic etiologies, presenting along a wide spectrum of potential symptoms. Nonpharmacologic treatment includes (1) increasing aerobic exercise, (2) lower-extremity strengthening, (3) increasing fluid/salt intake, (4) psychophysiologic training for management of pain/anxiety, and (5) family education. Pharmacologic treatment is recommended on a case-by-case basis, and can include beta-blocking agents to blunt orthostatic increases in heart rate, alpha-adrenergic agents to increase peripheral vascular resistance, mineralocorticoid agents to increase blood volume, and serotonin reuptake inhibitors. An interdisciplinary research approach may determine mechanistic root causes of symptoms, and is investigating novel management plans for affected patients.

  9. 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.

  10. Enhanced balance associated with coordination training with stochastic resonance stimulation in subjects with functional ankle instability: an experimental trial

    Directory of Open Access Journals (Sweden)

    Brown Cathleen N

    2007-12-01

    Full Text Available Abstract Background Ankle sprains are common injuries that often lead to functional ankle instability (FAI, which is a pathology defined by sensations of instability at the ankle and recurrent ankle sprain injury. Poor postural stability has been associated with FAI, and sports medicine clinicians rehabilitate balance deficits to prevent ankle sprains. Subsensory electrical noise known as stochastic resonance (SR stimulation has been used in conjunction with coordination training to improve dynamic postural instabilities associated with FAI. However, unlike static postural deficits, dynamic impairments have not been indicative of ankle sprain injury. Therefore, the purpose of this study was to examine the effects of coordination training with or without SR stimulation on static postural stability. Improving postural instabilities associated with FAI has implications for increasing ankle joint stability and decreasing recurrent ankle sprains. Methods This study was conducted in a research laboratory. Thirty subjects with FAI were randomly assigned to either a: 1 conventional coordination training group (CCT; 2 SR stimulation coordination training group (SCT; or 3 control group. Training groups performed coordination exercises for six weeks. The SCT group received SR stimulation during training, while the CCT group only performed coordination training. Single leg postural stability was measured after the completion of balance training. Static postural stability was quantified on a force plate using anterior/posterior (A/P and medial/lateral (M/L center-of-pressure velocity (COPvel, M/L COP standard deviation (COPsd, M/L COP maximum excursion (COPmax, and COP area (COParea. Results Treatment effects comparing posttest to pretest COP measures were highest for the SCT group. At posttest, the SCT group had reduced A/P COPvel (2.3 ± 0.4 cm/s vs. 2.7 ± 0.6 cm/s, M/L COPvel (2.6 ± 0.5 cm/s vs. 2.9 ± 0.5 cm/s, M/L COPsd (0.63 ± 0.12 cm vs. 0.73 ± 0

  11. Postural rehabilitation and Kinesio taping for axial postural disorders in Parkinson's disease.

    Science.gov (United States)

    Capecci, Marianna; Serpicelli, Chiara; Fiorentini, Luca; Censi, Giovanna; Ferretti, Matteo; Orni, Chiara; Renzi, Rosita; Provinciali, Leandro; Ceravolo, Maria Gabriella

    2014-06-01

    To assess the effects of postural rehabilitation (PR) on trunk asymmetry and balance, with and without Kinesio taping (KT) of the back muscles as additional treatment, in patients with Parkinson's disease (PD) who have postural disorders. Single-blind, randomized controlled trial with 1-month follow-up. Ambulatory care in referral center. Patients (N=20) with PD showing postural abnormalities of the trunk, in the sagittal and/or coronal plane. Four weeks of patient-tailored proprioceptive and tactile stimulation, combined with stretching and postural reeducation, was provided to 13 subjects (PR group), while 7 received no treatment (control group). Six of the 13 subjects receiving PR also had KT strips applied to their trunk muscles, according to the features of their postural abnormalities. Berg Balance Scale, Timed Up and Go, and degrees of trunk bending in the sagittal and coronal planes were assessed at the enrollment (t0), 1 month later (t1), and 2 months later (t2). At t1, all treated patients showed a significant improvement in trunk posture in both the sagittal (P=.002) and coronal planes (P=.01), compared with baseline. Moreover, they showed an improvement in measures of gait and balance (Pposture correction and trunk movements, muscle stretching, and proprioceptive stimulation may usefully impact PD axial symptoms. Repeated training is advocated to avoid waning of the effect. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  12. 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.

  13. Body posture and syndromes of back pain.

    Science.gov (United States)

    Nowotny, Janusz; Nowotny-Czupryna, Olga; Brzęk, Anna; Kowalczyk, Anna; Czupryna, Krzysztof

    2011-01-01

    The effects of faulty postures include disturbances of the symmetric distribution of compressive and tensile forces acting on both sides of the body axis and the emergence of harmful shear forces. The torques of antigravity muscles also change unfavourably. This may lead to the development of a repetitive strain syndrome, stenosis of intervertebral foramina, compression of nerve roots and back pain. The development of back pain syndromes is significantly affected by the performance of various work-related tasks in non-ergonomic positions. The aim of the study was to investigate the association between back pain syndromes and the quality of body posture, especially in the context of work ergonomics. The study enrolled 125 persons: 39 adults with a childhood history of scoliosis, 39 midwives, and 47 physiotherapists. Body posture was assessed in all participants. In midwives and physiotherapists, body position during the performance of work-related tasks was also evaluated. The frequency and severity of pain was assessed with the Jackson-Moskowitz measure. The study revealed that over 80% of the participants suffered from spinal pain. In most cases, the pain was intermittent and was felt in the lumbar spine. The occurrence of pain among midwives and physiotherapists was not directly dependent on the predominant type of abnormal spinal position assumed during the performance of occupational tasks or the quality of body posture. The complaint was also reported by ca. 85% of persons with a history of scoliosis. An incorrect body posture (especially scoliosis) and performance of work-related tasks in non-ergonomic positions increase the probability of back pain.

  14. Task-related and person-related variables influence the effect of low back pain on anticipatory postural adjustments.

    Science.gov (United States)

    Jacobs, Jesse V; Lyman, Courtney A; Hitt, Juvena R; Henry, Sharon M

    2017-08-01

    People with low back pain exhibit altered postural coordination that has been suggested as a target for treatment, but heterogeneous presentation has rendered it difficult to identify appropriate candidates and protocols for such treatments. This study evaluated the associations of task-related and person-related factors with the effect of low back pain on anticipatory postural adjustments. Thirteen subjects with and 13 without low back pain performed seated, rapid arm flexion in self-initiated and cued conditions. Mixed-model ANOVA were used to evaluate group and condition effects on APA onset latencies of trunk muscles, arm-raise velocity, and pre-movement cortical potentials. These measures were evaluated for correlation with pain ratings, Fear Avoidance Beliefs Questionnaire scores, and Modified Oswestry Questionnaire scores. Delayed postural adjustments of subjects with low back pain were greater in the cued condition than in the self-initiated condition. The group with low back pain exhibited larger-amplitude cortical potentials than the group without pain, but also significantly slower arm-raise velocities. With arm-raise velocity as a covariate, the effect of low back pain remained significant for the latencies of postural adjustments but not for cortical potentials. Latencies of the postural adjustments significantly correlated with Oswestry and Fear Avoidance Beliefs scores. Delayed postural adjustments with low back pain appear to be influenced by cueing of movement, pain-related disability and fear of activity. These results highlight the importance of subject characteristics, task condition, and task performance when comparing across studies or when developing treatment of people with low back pain. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Cineradiographic Analysis of Mouse Postural Response to Alteration of Gravity and Jerk (Gravity Deceleration Rate

    Directory of Open Access Journals (Sweden)

    Katsuya Hasegawa

    2014-04-01

    Full Text Available The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6 were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (<0.001 g. Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%–200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of −0.3~−0.4 j (g/s induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.

  16. Relationships between orientation, movement and posture in weightlessness: Preliminary ethological observations

    Science.gov (United States)

    Tafforin, Carole

    Weightlessness in man induces changes in astronaut orientations and consequently in his patterns of movements and postures. An ethological method has been used to describe the "overall" spontaneous behaviour of astronauts as seen from video recordings made during Space Flights. The work has consisted in analysing the relationships between orientation, movement and posture as an indication of a motor adaptative reorganization in such a situation. The results obtained lead us to consider three different aspects: (1) Orientation references. The astronaut orientates himself with reference to the Space Shuttle's internal structure; the increase of visual activity confirms the choice of the retinal vertical as frame of reference. (2) Motor coordination. The main data reveals a decrease in motor stereotypies by the diversity of motor acts observed and the importance of the link between orientation and posture described as follows: slightly inclined forward position, with legs flexed at about 135°. (3) Cognitive references. There appears to be a new organization of the cognitive image of the body scheme, the missing vestibular information being supplied by peripheral vision instead which could play a role in the astronaut's perception of his own movement.

  17. Postural- and respiratory-related activities of abdominal muscles during post-exercise hyperventilation.

    Science.gov (United States)

    David, Pascal; Terrien, Jérémy; Petitjean, Michel

    2015-05-01

    The present study focuses on the role of superficial abdominal muscles revealed by electromyographic recordings during the maintenance of a bipedal stance perturbed by post-exercise hyperventilation. Twelve healthy subjects performed six 30-s postural tests: one pre-exercise test while breathing quietly, then one test every minute for the 5 min immediately following a maximum-intensity, incremental cycling exercise test. Displacement of the centre of pressure in the sagittal plane was monitored over time. Myoelectric activities of the obliquus externus (OE), obliquus internus (OI) and rectus abdominis (RA) muscles were recorded by surface electromyography (EMG). Metabolic parameters were measured with a portable telemetric device. The change in ventilatory drive induced by exercise was accompanied by a significant increase in both postural sway parameters and EMG activities. For OE and OI, the increased EMG activities were prominent during expiration, whereas OI was silent during inspiration. OE and RA were activated during both expiration and inspiration. It is concluded that the compensation of respiratory disturbances of the erect posture appears to be less effective when minute ventilation increases. The patterns of muscle activity suggest that abdominal muscles are controlled differentially and that their functional coordination is dependent on the respiratory demand.

  18. Relationship between Postural Sway and Dynamic Balance in Stroke Patients.

    Science.gov (United States)

    Cho, Kihun; Lee, Kyoungsuk; Lee, Byungjoon; Lee, Hwangjae; Lee, Wanhee

    2014-12-01

    [Purpose] The purpose of the current study was to investigate the relationship between postural sway and dynamic balance in post stroke patients. [Subjects] Thirty-one stroke patients (20 men and 11 women; age 64.25 years; stroke duration 12.70 months; MMSE-K score 26.35) participated in this study. [Methods] This study applied a cross-sectional design. A Good Balance system was used for measurement of the postural sway velocity (anteroposterior and mediolateral) and velocity moment of subjects under the eyes open and eyes closed conditions in a standing posture. The postural sway of subjects was measured under two surface conditions (stable and unstable surfaces). [Results] On the unstable surface (foam), no significant correlation was observed between postural sway and dynamic balance except for the berg balance scale (BBS) score and anteroposterior postural sway velocity under the eyes open condition, anteroposterior postural sway velocity under the eyes closed condition, and postural sway velocity moment. In addition, in the stable condition, no significant correlation was observed between postural sway and dynamic balance. [Conclusion] Our results indicate that a decrease in postural sway does not necessarily reflect improvement of dynamic balance ability. We believe that this finding may be useful in balance rehabilitation for prevention of falls after a stroke.

  19. Neutral lumbar spine sitting posture in pain-free subjects.

    Science.gov (United States)

    O'Sullivan, Kieran; O'Dea, Patrick; Dankaerts, Wim; O'Sullivan, Peter; Clifford, Amanda; O'Sullivan, Leonard

    2010-12-01

    Sitting is a common aggravating factor in low back pain (LBP), and re-education of sitting posture is a common aspect of LBP management. However, there is debate regarding what is an optimal sitting posture. This pilot study had 2 aims; to investigate whether pain-free subjects can be reliably positioned in a neutral sitting posture (slight lumbar lordosis and relaxed thorax); and to compare perceptions of neutral sitting posture to habitual sitting posture (HSP). The lower lumbar spine HSP of seventeen pain-free subjects was initially recorded. Subjects then assumed their own subjectively perceived ideal posture (SPIP). Finally, 2 testers independently positioned the subjects into a tester perceived neutral posture (TPNP). The inter-tester reliability of positioning in TPNP was very good (intraclass correlation coefficient (ICC) = 0.91, mean difference = 3% of range of motion). A repeated measures ANOVA revealed that HSP was significantly more flexed than both SPIP and TPNP (p 0.05). HSP was more kyphotic than all other postures. This study suggests that pain-free subjects can be reliably positioned in a neutral lumbar sitting posture. Further investigation into the role of neutral sitting posture in LBP subjects is warranted. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Smart garment for trunk posture monitoring: A preliminary study

    Directory of Open Access Journals (Sweden)

    Wong Man

    2008-05-01

    Full Text Available Abstract Background Poor postures of the spine have been considered in association with a number of spinal musculoskeletal disorders, including structural deformity of the spine and back pain. Improper posturing for the patients with spinal disorders may further deteriorate their pain and deformities. Therefore, posture training has been proposed and its rationale is to use the patient's own back muscles to keep the spine within the natural curvature. A posture training device may help to facilitate this therapeutic approach by providing continuous posture monitoring and feedback signals to the patient when "poor" posture is detected. In addition, the users of the device may learn good postural habits that could carry over into their whole life. Methods A smart garment with integrated accelerometers and gyroscopes, which can detect postural changes in terms of curvature variation of the spine in the sagittal and coronal planes, has been developed with intention to facilitate posture training. The smart garment was evaluated in laboratory tests and with 5 normal subjects during their daily activities. Results Laboratory tests verified that the accuracy of the system is Conclusion The smart garment has been developed to be a portable and user-friendly trunk posture monitoring system and it could be used for collection of the trunk posture information and provision of instant feedback to the user if necessary for posture training purpose. The current pilot study demonstrated that the posture of normal subjects could be monitored and trained via this smart garment. With further clinical investigations, this system could be considered in some flexible spinal deformities such as scoliosis and kyphosis.

  1. Obesity impact on the attentional cost for controlling posture.

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Mignardot

    Full Text Available 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.

  2. The Theoretical Consideration on Postures and Worlds in Infants with Profound and Multiple Learning Difficultes

    OpenAIRE

    進, 一鷹; シン, カズタカ; Shin, Kazutaka

    1996-01-01

    This paper reports some research on the theoretical consideration on postures and worlds in infants with profound and multiple learning difficulties. Their relations to the world depends on their postures. The postures consists of four ones : i) the posture on their back, ii) the posture on their side, iii) the posure where they move from posture on their stomach to the posture in an upright position, iv) the posture in an upright position sitting at a desk. In the posture on their back, they...

  3. Movement and Coordination

    Science.gov (United States)

    ... Español Text Size Email Print Share Movement and Coordination Page Content Article Body At this age, your ... level will strengthen his body and develop his coordination. In the months ahead, your child’s running will ...

  4. Developmental coordination disorder

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001533.htm Developmental coordination disorder To use the sharing features on this page, please enable JavaScript. Developmental coordination disorder is a childhood disorder. It leads to ...

  5. The role of anticipatory postural adjustments in compensatory control of posture: 1. Electromyographic analysis.

    Science.gov (United States)

    Santos, Marcio J; Kanekar, Neeta; Aruin, Alexander S

    2010-06-01

    Anticipatory (APAs) and compensatory (CPAs) postural adjustments are the two principal mechanisms that the central nervous system uses to maintain equilibrium while standing. We studied the role of APAs in compensatory postural adjustments. Eight subjects were exposed to external predictable and unpredictable perturbations induced at the shoulder level, while standing with eyes open and closed. Electrical activity of leg and trunk muscles was recorded and analyzed during four epochs representing the time duration typical for anticipatory and compensatory postural control. No anticipatory activity of the trunk and leg muscles was seen in the case of unpredictable perturbations; instead, significant compensatory activation of muscles was observed. When the perturbations were predictable, strong anticipatory activation was seen in all the muscles: such APAs were associated with significantly smaller compensatory activity of muscles and COP displacements after the perturbations. The outcome of the study highlights the importance of APAs in control of posture and points out the existence of a relationship between the anticipatory and the compensatory components of postural control. It also suggests a possibility to enhance balance control by improving the APAs responses during external perturbations.

  6. Research of Human Postural Balance Parameters

    Directory of Open Access Journals (Sweden)

    Julius Griškevičius

    2011-02-01

    Full Text Available In present article postural balance between subjects with stroke and healthy subjects, is being investigated with eyes opened and eyes closed. In the research participated 30 healthy subjects and 15 subjects with stroke. At the same time two experimental measurements were performed – postural balance was measured using balance platform and oscillations of the centre of mass were observed using two-axial accelerometer. It was noted, that amplitudes of subjects with stroke were larger almost two times than control group’s of healthy subjects. It was find out, that ratios of pressure distribution on both left and right legs are in range from 1 to 0.9 for healthy subjects, and ratios below 0.9 are common for subjects with stroke. When subjects were standing with eyes closed, sway amplitudes were higher and the ratios of load distribution on left and right legs were lower.Article in Lithuanian

  7. Effects of posture on postoperative pulmonary function

    DEFF Research Database (Denmark)

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

    2003-01-01

    effect on postoperative pulmonary function in the sitting or standing position compared with the supine. Thus, avoidance of the supine position may improve postoperative pulmonary function. Three of six studies showed a positive effect on postoperative pulmonary function of the lateral side compared......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...... with the supine. Thus, the lateral position has limited effects on pulmonary function. CONCLUSION: Changes of postoperative position from supine to sitting or standing are of major importance in the interpretation of postoperative pulmonary outcome studies and in future strategies to improve pulmonary outcome....

  8. Wavelet based automated postural event detection and activity classification with single imu - biomed 2013.

    Science.gov (United States)

    Lockhart, Thurmon E; Soangra, Rahul; Zhang, Jian; Wu, Xuefan

    2013-01-01

    and classification algorithm using denoised signals from single wireless IMU placed at sternum. The algorithm was further validated and verified with motion capture system in laboratory environment. Wavelet denoising highlighted postural events and transition durations that further provided clinical information on postural control and motor coordination. The presented method can be applied in real life ambulatory monitoring approaches for assessing condition of elderly.

  9. Normative values for the Foot Posture Index

    Directory of Open Access Journals (Sweden)

    Redmond Anthony C

    2008-07-01

    Full Text Available Abstract Background The Foot Posture Index (FPI is a validated method for quantifying standing foot posture, and is being used in a variety of clinical settings. There have however, been no normative data available to date for comparison and reference. This study aimed to establish normative FPI reference values. Methods Studies reporting FPI data were identified by searching online databases. Nine authors contributed anonymised versions of their original datasets comprising 1648 individual observations. The datasets included information relating to centre, age, gender, pathology (if relevant, FPI scores and body mass index (BMI where available. FPI total scores were transformed to interval logit scores as per the Rasch model and normal ranges were defined. Comparisons between groups employed t-tests or ANOVA models as appropriate and data were explored descriptively and graphically. Results The main analysis based on a normal healthy population (n = 619 confirmed that a slightly pronated foot posture is the normal position at rest (mean back transformed FPI raw score = +4. A 'U' shaped relationship existed for age, with minors and older adults exhibiting significantly higher FPI scores than the general adult population (F = 51.07, p t = -1.44, p = 0.149. No relationship was found between the FPI and BMI. Systematic differences from the adult normals were confirmed in patients with neurogenic and idiopathic cavus (F = 216.981, p Conclusion A set of population norms for children, adults and older people have been derived from a large sample. Foot posture is related to age and the presence of pathology, but not influenced by gender or BMI. The normative values identified may assist in classifying foot type for the purpose of research and clinical decision making.

  10. Spinal postural training: Comparison of the postural and mobility effects of electrotherapy, exercise, biofeedback trainer in addition to postural education in university students.

    Science.gov (United States)

    Çelenay, Şeyda Toprak; Kaya, Derya Özer; Özüdoğru, Anıl

    2015-01-01

    Spinal posture and mobility are significant for protecting spine. The aim was to compare effects of different postural training interventions on spinal posture and mobility. Ninety-six university students (ages: 18–25 years) were allocated into Electrical Stimulation (ES) (n = 24), Exercise (n = 24), Biofeedback Posture Trainer (Backtone) (n = 24), and Postural Education (n = 24, Controls) groups. All the groups got postural education. The interventions were carried out 3 days a week for 8 weeks. Spinal Mouse device (Idiag, Fehraltorf, Switzerland) was used to detect thoracic and lumbar curvatures and mobility (degrees) in standing and sitting positions. Paired Student’s t-test, one-way ANOVA, and pairwise post-hoc tests were used. ES decreased thoracic curvature, the exercise decreased thoracic and lumbar curvature and increased thoracic mobility in standing position between pre-post training (p mobility increased compared to all groups (p mobility among university students. ES decreased thoracic curve. Biofeedback posture trainer improved sitting posture. A prospective randomized controlled trial, Level 1.

  11. Coordination and Cooperation

    OpenAIRE

    Janssen, Maarten

    2003-01-01

    textabstractThis comment makes four related points. First, explaining coordination is different from explaining cooperation. Second, solving the coordination problem is more important for the theory of games than solving the cooperation problem. Third, a version of the Principle of Coordination can be rationalized on individualistic grounds. Finally, psychological game theory should consider how players perceive their gaming situation. ---------------------------------------------------------...

  12. Processing Coordination Ambiguity

    Science.gov (United States)

    Engelhardt, Paul E.; Ferreira, Fernanda

    2010-01-01

    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based theories assume…

  13. Processing Coordination Ambiguity

    Science.gov (United States)

    Engelhardt, Paul E.; Ferreira, Fernanda

    2010-01-01

    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based…

  14. Coordination and Cooperation

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten)

    2003-01-01

    textabstractThis comment makes four related points. First, explaining coordination is different from explaining cooperation. Second, solving the coordination problem is more important for the theory of games than solving the cooperation problem. Third, a version of the Principle of Coordination can

  15. Coordination and Cooperation

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten)

    2003-01-01

    textabstractThis comment makes four related points. First, explaining coordination is different from explaining cooperation. Second, solving the coordination problem is more important for the theory of games than solving the cooperation problem. Third, a version of the Principle of Coordination can

  16. Postural dynamics and habituation to seasickness.

    Science.gov (United States)

    Tal, Dror; Bar, Ronen; Nachum, Zohar; Gil, Amnon; Shupak, Avi

    2010-07-26

    The computerized dynamic posturography (CDP) test examines the response pattern to simultaneous, multimodal sensory stimulation. The purpose of this prospective, controlled study was to investigate whether postural dynamics evaluated by CDP are related to seasickness severity and the process of habituation to sea conditions. Subjects included 74 naval personnel assigned to service aboard ship and 29 controls designated for shore-based positions. Study participants performed a baseline CDP test, and subsequent follow-up examinations 6 and 12 months after completion of their training. On those occasions they also completed a seasickness severity questionnaire. Longitudinal changes in postural parameters were examined, as well as a possible correlation between baseline CDP results and final seasickness severity scores. The results indicated longitudinal habituation to seasickness. Reduced scores were found for sensory organization sub-tests 3 and 5 in the first follow-up examination, reflecting increased weighting of visual and somatosensory input in the maintenance of balance. Scores in the second follow-up examination were above baseline values, indicating increased reliance on vestibular cues. These significant bimodal changes were found only in study subjects having the highest degree of habituation to seasickness. A significant decrease in motor response strength was found in parallel with increased habituation to seasickness. Baseline CDP results and postural control dynamics were not correlated with subjects' final seasickness severity score. These results suggest a potential role for CDP in monitoring the process of habituation to unusual motion conditions.

  17. Lead effects on postural balance of children

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, A.; Shukla, R.; Bornschein, R.L.; Dietrich, K.N. (Univ. of Cincinnati, OH (USA)); Keith, R. (Univ. of Cincinnati Medical Center, OH (USA))

    1990-11-01

    The postural sway responses of 63 children with a mean age of 5.74 years were quantified with a Force Platform technique. The average maximum (max) blood lead (PbB) of these children during the first 5 years of life was 20.7 {mu}g/dL (range 9.2 to 32.5). The backward stepwise regression analysis for sway area response during the eyes-closed, no-foam test with all the covariates and confounders and the PbB parameters showed a significant relationship with peak or max PbB during the second year of life. These results are consistent with their previous study with a smaller group of children. The data have been analyzed to provide some insight into the role of various afferents for the maintenance of postural balance. The results suggests a hypothesis that if the max PbB had caused some level of impairment in the functional capacities or interconnectivity of the vestibular and/or proprioception systems at 2 years of age, then it is reasonable to assume that the redundancy in the postural afferent systems would naturally adapt to rely more on the remaining intact afferent system (in this case, vision).

  18. Ice skating promotes postural control in children.

    Science.gov (United States)

    Keller, M; Röttger, K; Taube, W

    2014-12-01

    High fall rates causing injury and enormous financial costs are reported for children. However, only few studies investigated the effects of balance training in children and these studies did not find enhanced balance performance in postural (transfer) tests. Consequently, it was previously speculated that classical balance training might not be stimulating enough for children to adequately perform these exercises. Therefore, the aim of this study is to evaluate the influence of ice skating as an alternative form of balance training. Volunteers of an intervention (n = 17; INT: 13.1 ± 0.4 years) and a control group (n = 13; CON: 13.2 ± 0.3 years) were tested before and after training in static and dynamic postural transfer tests. INT participated in eight sessions of ice skating during education lessons, whereas CON participated in normal physical education. Enhanced balance performance was observed in INT but not in CON when tested on an unstable free-swinging platform (P children. More importantly, participating children improved static and dynamic balance control in postural tasks that were not part of the training.

  19. Multi-joint coordination in ballet dancers.

    Science.gov (United States)

    Thullier, Francine; Moufti, Hicham

    2004-10-07

    In upright posture, we analyzed the multi-joint coordination during drawing ellipses with the foot in a horizontal plane in classical ballet dancers (Elite) and gymnasts who had no dance training (Novice). In both groups, the stability of the head and the trunk was similar. Furthermore, a comparatively simple synergy inter-relating the movements in the hip, knee and ankle joints, was revealed by the kinematic analysis. However, novices made larger errors in the eccentricity and orientation of ellipses than ballet dancers. Ankle angular excursions were smaller in novices than in dancers whereas hip angular excursions were larger. This study illustrates some rules underlying the ability of the nervous system to integrate multiple degrees of freedom of the body to master body balance while producing complex leg movement trajectories. This study offers a dynamical approach of the problem of redundancy.

  20. Does extending the dual-task functional exercises workout improve postural balance in individuals with ID?

    Science.gov (United States)

    Mikolajczyk, Edyta; Jankowicz-Szymanska, Agnieszka

    2015-03-01

    Maintaining postural balance, overcoming visual and motor coordination disorders and experiencing problems with low general fitness - typical of intellectually disabled individuals - adversely affect the performance quality of their activities of daily living (ADLs). Physical fitness and postural balance can be improved by taking part in special intervention programs. Our study was designed to test whether extending the dual-task intervention program (combining ADLs with balance exercises on unstable surfaces) from 12 to 24 weeks additionally improved postural balance in individuals with intellectual disability (ID). We also attempted to assess whether the effects of the above intervention program were still noticeable after 8 weeks of holidays, in which participants did not take any rehabilitation exercises. A total of 34 adolescents, aged 14-16 years (15.06±0.9), with moderate ID took part in our study. The experimental group (E) consisted of 17 individuals, who continued the intervention program originated 3 months earlier, and the control group (C) comprised the same number of participants. Postural balance was assessed on a stabilometric platform Alfa. Having extended the workout period by another 12 weeks, we noticed that the path length of the center of pressure (COP) covered by participants on tests with their eyes open and closed significantly shortened. After a lapse of 8 weeks from the completion of the program, the experimental group revealed a statistically significant decrease in the velocity along the medio-lateral (M/L) and anterior-posterior (A/P) axes. The remaining variables stayed at the same level and the control group did not demonstrate any statistically significant changes. Dual-task exercises, in which enhancing functional tasks of daily living is combined with a parallel stimulation of balance reactions, may improve static balance in persons with ID.

  1. Postural control and perceptive configuration: influence of expertise in gymnastics.

    Science.gov (United States)

    Gautier, Geoffroy; Thouvarecq, Régis; Vuillerme, Nicolas

    2008-07-01

    The purpose of the present experiment was to investigate how postural adaptations to the perceptive configuration are modified by specific gymnastics experience. Two groups, one expert in gymnastics and the other non-expert, had to maintain the erected posture while optical flow was imposed as follows: 20s motionless, 30s approaching motion, and 20s motionless. The centre of pressure and head displacements were analysed. The postural adaptations were characterised by the variability of movements for the flow conditions and by the postural latencies for the flow transitions. The results showed that the gymnasts tended to minimise their body movements and were more stationary (head) but not more stable (COP) than the non-gymnasts. These results suggest that gymnastics experience develops a specific postural adaptability relative to the perceptive configuration. We conclude that a specific postural experience could be considered as an intrinsic constraint, which leads to modification in the patterns of functional adaptation in the perceptive motor space.

  2. Illusory visual motion stimulus elicits postural sway in migraine patients

    Directory of Open Access Journals (Sweden)

    Shu eImaizumi

    2015-04-01

    Full Text Available Although the perception of visual motion modulates postural control, it is unknown whether illusory visual motion elicits postural sway. The present study examined the effect of illusory motion on postural sway in patients with migraine, who tend to be sensitive to it. We measured postural sway for both migraine patients and controls while they viewed static visual stimuli with and without illusory motion. The participants’ postural sway was measured when they closed their eyes either immediately after (Experiment 1, or 30 seconds after (Experiment 2, viewing the stimuli. The patients swayed more than the controls when they closed their eyes immediately after viewing the illusory motion (Experiment 1, and they swayed less than the controls when they closed their eyes 30 seconds after viewing it (Experiment 2. These results suggest that static visual stimuli with illusory motion can induce postural sway that may last for at least 30 seconds in patients with migraine.

  3. Difficulty leading interpersonal coordination: Towards an embodied signature of social anxiety disorder

    Directory of Open Access Journals (Sweden)

    Manuel eVarlet

    2014-02-01

    Full Text Available Defined by a persistent fear of embarrassment or negative evaluation while engaged in social interaction or public performance, social anxiety disorder (SAD is one of the most common psychiatric syndromes. Previous research has made a considerable effort to better understand and assess this mental disorder. However, little attention has been paid to social motor behavior of patients with SAD despite its crucial importance in daily social interactions. Previous research has shown that the coordination of arm, head or postural movements of interacting people can reflect their mental states or feelings such as social connectedness and social motives, suggesting that interpersonal movement coordination may be impaired in patients suffering from SAD. The current study was specifically aimed at determining whether SAD affects the dynamics of social motor coordination. We compared the unintentional and intentional rhythmic coordination of a SAD group (19 patients paired with control participants with the rhythmic coordination of a control group (19 control pairs in an interpersonal pendulum coordination task. The results demonstrated that unintentional social motor coordination was preserved with SAD while intentional coordination was impaired. More specifically, intentional coordination became impaired when patients with SAD had to lead the coordination as indicated by poorer (i.e., more variable coordination. These differences between intentional and unintentional coordination as well as between follower and leader roles reveal an impaired coordination dynamics that is specific to SAD, and thus, opens promising research directions to better understand, assess and treat this mental disorder.

  4. Increased dynamic regulation of postural tone through Alexander Technique training

    OpenAIRE

    Cacciatore, TW; Gurfinkel, VS; Horak, FB; Cordo, PJ; Ames, KE

    2010-01-01

    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 modulati...

  5. Head and scapular posture in flutists: a pilot controlled study

    OpenAIRE

    Teixeira, Z; Lã, F; Silva, A.

    2011-01-01

    Instrumental practice which requires asymmetrical postures might, in the long term, potentiate musculoskeletal disorders and lead to pain. This, in turn, may have a negative impact on musical performance quality. Thus, the assessment of postural deviations among musicians is of the outmost importance in instrumental pedagogy. This study aims to compare the head and scapular posture of flutists with different levels of expertise and a control group of singers. Results suggest...

  6. The relationship between the stomatognathic system and body posture

    OpenAIRE

    Antonino Cuccia; Carola Caradonna

    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. ...

  7. Time-of-day influences postural balance in older adults

    DEFF Research Database (Denmark)

    Jorgensen, M G; Rathleff, M S; 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 unknown...... in older adults. The aim of this study was to investigate the time-of-day effect on postural balance in older adults....

  8. Clinical characteristics of patients with persistent postural-perceptual dizziness

    OpenAIRE

    Roseli Saraiva Moreira Bittar; Eliane Maria Dias von Söhsten Lins

    2015-01-01

    INTRODUCTION: Persistent postural-perceptual dizziness is the dizziness that lasts for over three months with no clinical explanation for its persistence. The patient's motor response pattern presents changes and most patients manifest significant anxiety. OBJECTIVE: To evaluate the clinical characteristics of patients with persistent postural and perceptual dizziness. METHODS: statistical analysis of clinical aspects of patients with persistent postural-perceptual dizziness. RESULTS: 81 pati...

  9. Effects of hippotherapy on posture in individuals with Down Syndrome

    OpenAIRE

    Espindula, Ana Paula; Ribeiro,Mariane Fernandes; Souza,Luciane Aparecida Pascucci Sande de; Ferreira,Alex Abadio; Ferraz,Mara Lúcia da Fonseca; Teixeira,Vicente de Paula Antunes

    2016-01-01

    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 individual...

  10. 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

  11. Postural responses explored through classical conditioning.

    Science.gov (United States)

    Campbell, A D; Dakin, C J; Carpenter, M G

    2009-12-15

    The purpose of the study was to determine whether the central nervous system (CNS) requires the sensory feedback generated by balance perturbations in order to trigger postural responses (PRs). In Experiment 1, twenty-one participants experienced toes-up support-surface tilts in two blocks. Control blocks involved unexpected balance perturbations whereas an auditory tone cued the onset of balance perturbations in Conditioning blocks. A single Cue-Only trial followed each block (Cue-Only(Control) and Cue-Only(Conditioning) trials) in the absence of balance perturbations. Cue-Only(Conditioning) trials were used to determine whether postural perturbations were required in order to trigger PRs. Counter-balancing the order of Control and Conditioning blocks allowed Cue-Only(Control) trials to examine both the audio-spinal/acoustic startle effects of the auditory cue and the carryover effects of the initial conditioning procedure. In Experiment 2, six participants first experienced five consecutive Tone-Only trials that were followed by twenty-five conditioning trials. After conditioning, five Tone-Only trials were again presented consecutively to first elicit and then extinguish the conditioned PRs. Surface electromyography (EMG) recorded muscle activity in soleus (SOL), tibialis anterior (TA) and rectus femoris (RF). EMG onset latencies and amplitudes were calculated together with the onset latency, peak and time-to-peak of shank angular accelerations. Results indicated that an auditory cue could be conditioned to initiate PRs in multiple muscles without balance-relevant sensory triggers generated by balance perturbations. Postural synergies involving excitation of TA and RF and inhibition of SOL were observed following the Cue-Only(Conditioning) trials that resulted in shank angular accelerations in the direction required to counter the expected toes-up tilt. Postural synergies were triggered in response to the auditory cue even 15 min post-conditioning. Furthermore

  12. Difference in Postural Control during Quiet Standing between Young Children and Adults: Assessment with Center of Mass Acceleration.

    Science.gov (United States)

    Oba, Naoko; Sasagawa, Shun; Yamamoto, Akio; Nakazawa, Kimitaka

    2015-01-01

    The development of upright postural control has often been investigated using time series of center of foot pressure (COP), which is proportional to the ankle joint torque (i.e., the motor output of a single joint). However, the center of body mass acceleration (COMacc), which can reflect joint motions throughout the body as well as multi-joint coordination, is useful for the assessment of the postural control strategy at the whole-body level. The purpose of the present study was to investigate children's postural control during quiet standing by using the COMacc. Ten healthy children and 15 healthy young adults were instructed to stand upright quietly on a force platform with their eyes open or closed. The COMacc as well as the COP in the anterior-posterior direction was obtained from ground reaction force measurement. We found that both the COMacc and COP could clearly distinguish the difference between age groups and visual conditions. We also found that the sway frequency of COMacc in children was higher than that in adults, for which differences in biomechanical and/or neural factors between age groups may be responsible. Our results imply that the COMacc can be an alternative force platform measure for assessing developmental changes in upright postural control.

  13. Difference in Postural Control during Quiet Standing between Young Children and Adults: Assessment with Center of Mass Acceleration.

    Directory of Open Access Journals (Sweden)

    Naoko Oba

    Full Text Available The development of upright postural control has often been investigated using time series of center of foot pressure (COP, which is proportional to the ankle joint torque (i.e., the motor output of a single joint. However, the center of body mass acceleration (COMacc, which can reflect joint motions throughout the body as well as multi-joint coordination, is useful for the assessment of the postural control strategy at the whole-body level. The purpose of the present study was to investigate children's postural control during quiet standing by using the COMacc. Ten healthy children and 15 healthy young adults were instructed to stand upright quietly on a force platform with their eyes open or closed. The COMacc as well as the COP in the anterior-posterior direction was obtained from ground reaction force measurement. We found that both the COMacc and COP could clearly distinguish the difference between age groups and visual conditions. We also found that the sway frequency of COMacc in children was higher than that in adults, for which differences in biomechanical and/or neural factors between age groups may be responsible. Our results imply that the COMacc can be an alternative force platform measure for assessing developmental changes in upright postural control.

  14. 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

    . 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...... in the Romberg position with eyes closed, but not with eyes open. 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...

  15. The Effect of Training on Postural Control in Dyslexic Children

    Science.gov (United States)

    Goulème, Nathalie; Gérard, Christophe-Loïc; Bucci, Maria Pia

    2015-01-01

    The aim of this study was to explore whether a short postural training period could affect postural stability in dyslexic children. Postural performances were evaluated using Multitest Equilibre from Framiral. Posture was recorded in three different viewing conditions (eyes open fixating a target, eyes closed and eyes open with perturbed vision) and in two different postural conditions (on stable and unstable support). Two groups of dyslexic children participated in the study, i.e. G1: 16 dyslexic participants (mean age 9.9 ± 0.3 years) who performed short postural training and G2: 16 dyslexic participants of similar ages (mean age 9.1 ± 0.3 years) who did not perform any short postural training. Findings showed that short postural training improved postural stability on unstable support surfaces with perturbed vision: indeed the surface, the mean velocity of CoP and the spectral power indices in both directions decreased significantly, and the cancelling time in the antero-posterior direction improved significantly. Such improvement could be due to brain plasticity, which allows better performance in sensory process and cerebellar integration. PMID:26162071

  16. Eye Movements Affect Postural Control in Young and Older Females.

    Science.gov (United States)

    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.

  17. 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.

  18. Physical Workload Analysis Among Small Industry Activities Using Postural Data.

    Science.gov (United States)

    Rabiul Ahasan, M; Väyrynen, Seppo; Kirvesoja, Heli

    1996-01-01

    Small industry workers are often involved in manual handling operations that require awkward body postures, therefore, musculoskeletal disorders and occupational injuries are a major problem. In this study, various types of tasks were recorded with a video camera to chart and analyze different postures by computerized OWAS (Ovako Working Posture Analysing System). Collected data showed that poor postures were adopted not only for lifting or hammering operation but also for other tasks; mostly with bent and twisted back. The main aim was to determine the physical workload by identifying harmful postures and to develop recommendations for improving the existing situation. Forty-eight male workers from eight different units (M age = 37 years) participated. The performed activities were then divided into 26 subtasks. Altogether, 1,534 postures were selected for analysis and then classified into different OAC (OWAS Action Categories). From all observations, unhealthy postures, for which corrective measures had to be considered immediately (i.e., 10.6% classified as OAC III, and 3.3% as OAC IV), were found. The applied method was useful in determining the physical workload by locating potential activities due to harmful postures, providing a detailed description with analysis, and suggesting successful means to reduce postural load.

  19. Effect of different insoles on postural balance: a systematic review.

    Science.gov (United States)

    Christovão, Thaluanna Calil Lourenço; Neto, Hugo Pasini; Grecco, Luanda André Collange; Ferreira, Luiz Alfredo Braun; Franco de Moura, Renata Calhes; Eliege de Souza, Maria; Franco de Oliveira, Luis Vicente; Oliveira, Claudia Santos

    2013-10-01

    [Purpose] The aim of the present study was to perform a systematic review of the literature on the effect of different insoles on postural balance. [Subjects and Methods] A systematic review was conducted of four databases. The papers retrieved were evaluated based on the following inclusion criteria: 1) design: controlled clinical trial; 2) intervention: insole; 3) outcome: change in static postural balance; and 4) year of publication: 2005 to 2012. [Results] Twelve controlled trials were found comparing the effects of different insoles on postural balance. The papers had methodological quality scores of 3 or 4 on the PEDro scale. [Conclusion] Insoles have benefits that favor better postural balance and control.

  20. Subacromial impingement syndrome: the role of posture and muscle imbalance.

    Science.gov (United States)

    Lewis, Jeremy S; Green, Ann; Wright, Christine

    2005-01-01

    Changes in upper body posture, colloquially termed forward head posture (FHP), are considered to be an etiologic factor in the pathogenesis of subacromial impingement syndrome (SIS). The literature suggests that postural deviations associated with FHP follow distinct patterns involving an increase in the thoracic kyphosis angle and a downwardly rotated, anteriorly tilted, and protracted scapula, which in turn leads to increased compression in the subacromial space. These postural changes are thought to occur concurrently with an imbalance of the musculature, and conservative rehabilitation commonly involves addressing both posture and muscle imbalance. There is a paucity of evidence supporting the hypothesis that posture and muscle imbalance are involved in the etiology of SIS. The purpose of this study was to investigate whether FHP was associated with an increased thoracic kyphosis, an altered position of the scapula; and a reduction in glenohumeral elevation range. Selected sagittal and frontal plane postural measurements were made in 60 asymptomatic subjects and 60 subjects with SIS. The findings suggested that upper body posture does not follow the set patterns described in the literature, and further research is required to determine whether upper body and scapular posture and muscle imbalance are involved in the pathogenesis of SIS.

  1. Saccades improve postural control: a developmental study in normal children.

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    Layla Ajrezo

    Full Text Available INTRODUCTION: Dual-task performance is known to affect postural stability in children. This study focused on the effect of oculomotor tasks like saccadic eye movements on postural stability, studied in a large population of children by recording simultaneously their eye movements and posture. MATERIALS AND METHODS: Ninety-five healthy children from 5.8 to 17.6 years old were examined. All children were free of any vestibular, neurological, ophtalmologic and orthoptic abnormalities. Postural control was measured with a force platform TechnoConcept®, and eye movements with video oculography (MobilEBT®. Children performed two oculomotor tasks: fixation of a stable central target and horizontal saccades. We measured the saccade latency and the number of saccades during fixation as well as the surface, length and mean velocity of the center of pressure. RESULTS: During postural measurement, we observed a correlation between the age on the one hand and a decrease in saccade latency as well as an improvement in the quality of fixation on the other. Postural sway decreases with age and is reduced in the dual task (saccades in comparison with a simple task of fixation. DISCUSSION - CONCLUSION: These results suggest a maturation of neural circuits controlling posture and eye movements during childhood. This study also shows the presence of an interaction between the oculomotor system and the postural system. Engaging in oculomotor tasks results in a reduction of postural sway.

  2. The Effect of Training on Postural Control in Dyslexic Children.

    Science.gov (United States)

    Goulème, Nathalie; Gérard, Christophe-Loïc; Bucci, Maria Pia

    2015-01-01

    The aim of this study was to explore whether a short postural training period could affect postural stability in dyslexic children. Postural performances were evaluated using Multitest Equilibre from Framiral. Posture was recorded in three different viewing conditions (eyes open fixating a target, eyes closed and eyes open with perturbed vision) and in two different postural conditions (on stable and unstable support). Two groups of dyslexic children participated in the study, i.e. G1: 16 dyslexic participants (mean age 9.9 ± 0.3 years) who performed short postural training and G2: 16 dyslexic participants of similar ages (mean age 9.1 ± 0.3 years) who did not perform any short postural training. Findings showed that short postural training improved postural stability on unstable support surfaces with perturbed vision: indeed the surface, the mean velocity of CoP and the spectral power indices in both directions decreased significantly, and the cancelling time in the antero-posterior direction improved significantly. Such improvement could be due to brain plasticity, which allows better performance in sensory process and cerebellar integration.

  3. Postural control in strabismic children: importance of proprioceptive information

    OpenAIRE

    Cynthia eLIONS; Emmanuel eBui Quoc; Sylvette eWiener-Vacher; Maria Pia eBucci

    2014-01-01

    ObjectiveTo examine the effect of proprioceptive information during postural control in strabismic children.MethodsPostural stability was recorded with a platform (Techno Concept®) in twelve strabismic children aged from 4.9 to 10 years and data were compared to that of twelve control age-matched children. Two postural positions were performed: Romberg and Tandem. Two postural conditions: without and with foam pad. We analyzed the surface area, the length, the mean speed of the center of pres...

  4. The Effect of Training on Postural Control in Dyslexic Children.

    Directory of Open Access Journals (Sweden)

    Nathalie Goulème

    Full Text Available The aim of this study was to explore whether a short postural training period could affect postural stability in dyslexic children. Postural performances were evaluated using Multitest Equilibre from Framiral. Posture was recorded in three different viewing conditions (eyes open fixating a target, eyes closed and eyes open with perturbed vision and in two different postural conditions (on stable and unstable support. Two groups of dyslexic children participated in the study, i.e. G1: 16 dyslexic participants (mean age 9.9 ± 0.3 years who performed short postural training and G2: 16 dyslexic participants of similar ages (mean age 9.1 ± 0.3 years who did not perform any short postural training. Findings showed that short postural training improved postural stability on unstable support surfaces with perturbed vision: indeed the surface, the mean velocity of CoP and the spectral power indices in both directions decreased significantly, and the cancelling time in the antero-posterior direction improved significantly. Such improvement could be due to brain plasticity, which allows better performance in sensory process and cerebellar integration.

  5. Transfer of postural adaptation depends on context of prior exposure.

    Science.gov (United States)

    Pienciak-Siewert, Alison; Barletta, Anthony J; Ahmed, Alaa A

    2014-04-01

    Postural control is significantly affected by the postural base of support; however, the effects on postural adaptation are not well understood. Here we investigated how adaptation and transfer of anticipatory postural control are affected by stance width. Subjects made reaching movements in a novel dynamic environment while holding the handle of a force-generating robotic arm. Each subject initially adapted to the dynamics while standing in a wide stance and then switched to a narrow stance, or vice versa. Our hypothesis is that anticipatory postural control, reflected in center of pressure (COP) movement, is not affected by stance width, as long as the control remains within functional limits; therefore we predicted that subjects in either stance would show similar COP movement by the end of adaptation and immediately upon transfer to the other stance. We found that both groups showed similar adaptation of postural control, by using different muscle activation strategies to account for the differing stance widths. One group, after adapting in wide stance, transferred similar postural control to narrow stance, by modifying their muscle activity to account for the new stance. Interestingly, the other group showed an increase in postural control when transferring from narrow to wide stance, associated with no change in muscle activity. These results confirm that adaptation of anticipatory postural control is not affected by stance width, as long as the control remains within biomechanical limits. However, transfer of control between stance widths is affected by the initial context in which the task is learned.

  6. Investigation of compensatory postures with videofluoromanometry in dysphagia patients

    Institute of Scientific and Technical Information of China (English)

    Antonio Solazzo; Luigi Monaco; Lucia Del Vecchio; Stefania Tamburrini; Francesca Iacobellis; Daniela Berritto; Nunzia Luisa Pizza

    2012-01-01

    AIM:To investigate the effectiveness of head compensatory postures to ensure safe oropharyngeal transit.METHODS:A total of 321 dysphagia patients were enrolled and assessed with videofluoromanometry (VFM).The dysphagia patients were classified as follows:safe transit; penetration without aspiration; aspiration before,during or after swallowing; multiple aspirations and no transit.The patients with aspiration or no transit were tested with VFM to determine whether compensatory postures could correct their swallowing disorder.RESULTS:VFM revealed penetration without aspiration in 71 patients (22.1%); aspiration before swallowing in 17 patients (5.3%); aspiration during swallowing in 32 patients (10%); aspiration after swallowing in 21 patients (6.5%); multiple aspirations in six patients (1.9%); no transit in five patients (1.6%); and safe transit in 169 patients (52.6%).Compensatory postures guaranteed a safe transit in 66/75 (88%) patients with aspiration or no transit.A chin-down posture achieved a safe swallow in 42/75 (56%) patients,a head-turned posture in 19/75 (25.3%) and a hyperextended head posture in 5/75 (6.7%).The compensatory postures were not effective in 9/75 (12%) cases.CONCLUSION:VFM allows the speech-language therapist to choose the most effective compensatory posture without a trial-and-error process and check the effectiveness of the posture.

  7. Improved Dynamic Postural Task Performance without Improvements in Postural Responses: The Blessing and the Curse of Dopamine Replacement

    Directory of Open Access Journals (Sweden)

    K. B. Foreman

    2012-01-01

    Full Text Available Introduction. Dopamine-replacement medications may improve mobility while not improving responses to postural challenges and could therefore increase fall risk. The purpose of this study was to measure reactive postural responses and gait-related mobility of patients with PD during ON and OFF medication conditions. Methods. Reactive postural responses to the Pull Test and performance of the Functional Gait Assessment (FGA were recorded from 15 persons with PD during ON and OFF medication conditions. Results. Persons with PD demonstrated no significant difference in the reactive postural responses between medication conditions but demonstrated significantly better performance on the FGA when ON medications compared to OFF. Discussion/Conclusion. Dopamine-replacement medications alone may improve gait-related mobility without improvements in reactive postural responses and therefore could result in iatrogenic increases in fall risk. Rehabilitation providers should be aware of the side effects and limitations of medication treatment and implement interventions to improve postural responses.

  8. Anticipatory Postural Adjustments associated with reaching movements are programmed according to the availability of visual information.

    Science.gov (United States)

    Esposti, Roberto; Bruttini, Carlo; Bolzoni, Francesco; Cavallari, Paolo

    2017-02-17

    During goal-directed arm movements, the eyes, head, and arm are coordinated to look at and reach the target. We examined whether the expectancy of visual information about the target modifies Anticipatory Postural Adjustments (APAs). Ten standing subjects had to (1) move the eyes, head and arm, so as to reach, with both gaze and index-finger, a target of known position placed outside their visual field (Gaze-Reach); (2) look at the target while reaching it (Reach in Full Vision); (3) keep the gaze away until having touched it (Reach then Gaze) and (4) just Gaze without Reach the target. We recorded eye, head, right arm, and acromion kinematics, EMGs from upper- and lower-limb muscles, and forces exerted on the ground. In Gaze-Reach, two coordination strategies were found: when gaze preceded arm muscle recruitment (Gaze-first) and when the opposite occurred (Reach-first). APAs in acromion kinematics, leg muscles, and ground forces started significantly earlier in Gaze-first vs. Reach-first (mean time advance: 44.3 ± 8.9 ms), as it was in Reach in Full Vision vs. Reach then Gaze (39.5 ± 7.9 ms). The Gaze-first to Reach-first time-shift was similar to that between Reach in Full Vision and Reach then Gaze (p = 0.58). Moreover, Gaze without Reach data witnessed that the head-induced postural actions did not affect the APA onset in Gaze-first and Reach-first. In conclusion, in Gaze-first, the central control of posture considers visual information while planning the movement, like in Reach in Full Vision; while Reach-first is more similar to Reach then Gaze, where vision is not required.

  9. Comparing Postural Stability Entropy Analyses to Differentiate Fallers and Non-fallers.

    Science.gov (United States)

    Fino, Peter C; Mojdehi, Ahmad R; Adjerid, Khaled; Habibi, Mohammad; Lockhart, Thurmon E; Ross, Shane D

    2016-05-01

    The health and financial cost of falls has spurred research to differentiate the characteristics of fallers and non-fallers. Postural stability has received much of the attention with recent studies exploring various measures of entropy. This study compared the discriminatory ability of several entropy methods at differentiating two paradigms in the center-of-pressure of elderly individuals: (1) eyes open (EO) vs. eyes closed (EC) and (2) fallers (F) vs. non-fallers (NF). Methods were compared using the area under the curve (AUC) of the receiver-operating characteristic curves developed from logistic regression models. Overall, multiscale entropy (MSE) and composite multiscale entropy (CompMSE) performed the best with AUCs of 0.71 for EO/EC and 0.77 for F/NF. When methods were combined together to maximize the AUC, the entropy classifier had an AUC of for 0.91 the F/NF comparison. These results suggest researchers and clinicians attempting to create clinical tests to identify fallers should consider a combination of every entropy method when creating a classifying test. Additionally, MSE and CompMSE classifiers using polar coordinate data outperformed rectangular coordinate data, encouraging more research into the most appropriate time series for postural stability entropy analysis.

  10. Observations of working postures in garages using the Ovako Working posture Analysing System (OWAS) and consequent workload reduction recommendations.

    Science.gov (United States)

    Kant, I; Notermans, J H; Borm, P J

    1990-02-01

    The working postures of mechanics (n = 84) in 42 garages were observed using the Ovako Working posture Analysis System (OWAS). During observation, both working postures and work activities were recorded. A computer program was developed for the data analyses. Using this program it is possible to calculate the working posture load for each work activity and the contribution of a specific activity to the total working posture load. This is a substantial extension of the original OWAS method. Five out of 19 observed postures of the body members were classified as Action Category 2, which suggests they were slightly harmful to the musculoskeletal system and likely to cause discomfort. Of the so-called typical working postures, 31.9% was classified in Action Category 2, suggesting that during a substantial part of the working day typical working postures occur which are at least slightly harmful to the musculoskeletal system. Moreover, those work activities principally causing the workload to fall in OWAS' higher Action Categories were identified. For each of these three work activities an alternative work method was observed. The data show that in all three work activities the use of a vehicle lift reduces the number of poor working postures thereby reducing the load on the musculoskeletal system.

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

    NARCIS (Netherlands)

    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.

    2014-01-01

    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 st

  12. Control of postural alignment in patients with Parkinsons disease: analysis through postural software (SAPO

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    Lucia Martins Barbatto

    2013-10-01

    Full Text Available This study assesses the alignment of posture and postural control in patients with Parkinson’s disease (PD. Fifty individuals, aged 60–80 years, were viewed in the anterior, posterior, right lateral, and left positions by software for postural assessment (SAPO. The individuals were grouped according to the disease stage and the stage of medication (i.e. “on” or “off” levodopa. In the intermediate to advanced stages, there was a significant standard deviation in the horizontal alignment acromions, in the horizontal alignment of the anterior superior iliac spines, and in the angle between the acromia and the two anterior superior iliac spines. The side view of the left and right relationships was statistically significant for all variables. The “on” stage and the “off” stage groups showed no significant deviation. There was no statistically significant correlation between the center of gravity in the frontal and sagittal planes of the dominant hand and the side of symptom onset. In PD, individuals have increased cervical lordosis and thoracic kyphosis; an anteriorized head; reduced lumbar curvature; increased valgus, increased knee flexion angle; a decline in the support base; zero step; reduced postural stability; anteriorized center of gravity; and changes in the base of support.

  13. Both anticipatory and compensatory postural adjustments are adapted while catching a ball in unstable standing posture.

    Science.gov (United States)

    Scariot, Vanessa; Rios, Jaqueline L; Claudino, Renato; dos Santos, Eloá C; Angulski, Hanna B B; dos Santos, Marcio J

    2016-01-01

    The main objective of this study was to analyze the role of balance exercises on anticipatory (APA) and compensatory (CPA) postural adjustments in different conditions of postural stability. Sixteen subjects were required to catch a ball while standing on rigid floor, trampoline and foam cushion surfaces. Electromyographic activities (EMG) of postural muscles were analyzed during time windows typical for APAs and CPAs. Overall there were a reciprocal activation of the muscles around the ankle and co-activations between ventral and dorsal muscles of the thigh and trunk during the catching a ball task. Compared to the rigid floor, the tibialis anterior activation was greater during the trampoline condition (CPA: p = 0.006) and the soleus muscle inhibition was higher during foam cushion condition (APA: p = 0.001; CPA: p = 0.007). Thigh and trunk muscle activities were similar across the conditions. These results advance the knowledge in postural control during body perturbations standing on unstable surfaces.

  14. Directional specificity of postural threat on anticipatory postural adjustments during lateral leg raising.

    Science.gov (United States)

    Gendre, Manon; Yiou, Eric; Gélat, Thierry; Honeine, Jean-Louis; Deroche, Thomas

    2016-03-01

    This study explored the directional specificity of fear of falling (FoF) effects on the stabilizing function of anticipatory postural adjustments (APA). Participants (N = 71) performed a series of lateral leg raises from an elevated surface in three conditions: in the "Control condition", participants stood at the middle of the surface; in the two test conditions, participants were positioned at the lateral edge of the surface so that the shift of the whole-body centre-of-mass during APA for leg raising was directed towards the edge ("Approach condition") or was directed away from the edge ("Avoidance condition"). Results showed that the amplitude of APA was lower in the "Approach condition" than in the "Control condition" (p postural stability and motor performance (in terms of peak leg velocity, final leg posture and movement duration) remained unchanged. These changes in APA parameters were not present in the "Avoidance condition". Participants further self-reported a greater FoF (p Control condition". The results of this study show that the effects of FoF do not solely depend on initial environmental conditions, but also on the direction of APA relative to the location of the postural threat. These results support the so-called Motivational Direction Hypothesis, according to which approach and avoidance behaviours are primed by emotional state.

  15. Postural Hand Synergies during Environmental Constraint Exploitation

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    Cosimo Della Santina

    2017-08-01

    Full Text Available Humans are able to intuitively exploit the shape of an object and environmental constraints to achieve stable grasps and perform dexterous manipulations. In doing that, a vast range of kinematic strategies can be observed. However, in this work we formulate the hypothesis that such ability can be described in terms of a synergistic behavior in the generation of hand postures, i.e., using a reduced set of commonly used kinematic patterns. This is in analogy with previous studies showing the presence of such behavior in different tasks, such as grasping. We investigated this hypothesis in experiments performed by six subjects, who were asked to grasp objects from a flat surface. We quantitatively characterized hand posture behavior from a kinematic perspective, i.e., the hand joint angles, in both pre-shaping and during the interaction with the environment. To determine the role of tactile feedback, we repeated the same experiments but with subjects wearing a rigid shell on the fingertips to reduce cutaneous afferent inputs. Results show the persistence of at least two postural synergies in all the considered experimental conditions and phases. Tactile impairment does not alter significantly the first two synergies, and contact with the environment generates a change only for higher order Principal Components. A good match also arises between the first synergy found in our analysis and the first synergy of grasping as quantified by previous work. The present study is motivated by the interest of learning from the human example, extracting lessons that can be applied in robot design and control. Thus, we conclude with a discussion on implications for robotics of our findings.

  16. Enhanced time overcurrent coordination

    Energy Technology Data Exchange (ETDEWEB)

    Enriquez, Arturo Conde; Martinez, Ernesto Vazquez [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, Apdo. Postal 114-F, Ciudad Universitaria, CP 66450 San Nicolas de los Garza, Nuevo Leon (Mexico)

    2006-04-15

    In this paper, we recommend a new coordination system for time overcurrent relays. The purpose of the coordination process is to find a time element function that allows it to operate using a constant back-up time delay, for any fault current. In this article, we describe the implementation and coordination results of time overcurrent relays, fuses and reclosers. Experiments were carried out in a laboratory test situation using signals of a power electrical system physics simulator. (author)

  17. Taekwondo Training Improves Sensory Organization and Balance Control in Children with Developmental Coordination Disorder: A Randomized Controlled Trial

    Science.gov (United States)

    Fong, Shirley S. M.; Tsang, William W. N.; Ng, Gabriel Y. F.

    2012-01-01

    Children with developmental coordination disorder (DCD) have poorer postural control and are more susceptible to falls and injuries than their healthy counterparts. Sports training may improve sensory organization and balance ability in this population. This study aimed to evaluate the effects of three months of Taekwondo (TKD) training on the…

  18. Taekwondo Training Improves Sensory Organization and Balance Control in Children with Developmental Coordination Disorder: A Randomized Controlled Trial

    Science.gov (United States)

    Fong, Shirley S. M.; Tsang, William W. N.; Ng, Gabriel Y. F.

    2012-01-01

    Children with developmental coordination disorder (DCD) have poorer postural control and are more susceptible to falls and injuries than their healthy counterparts. Sports training may improve sensory organization and balance ability in this population. This study aimed to evaluate the effects of three months of Taekwondo (TKD) training on the…

  19. Continuity and Contingency in USAF Posture Planning

    Science.gov (United States)

    2016-01-01

    USAF posture by making it more stable in the face of political or budgetary pressures or strategy changes that may be short sighted . On the other hand...distinct from some types of gambling in closed systems with known odds. For more on the latter, see Nate Silver , The Signal and the Noise: Why So Many...Resolution,” as that makes the law sound like something less than what it is—a bill passed by both the Senate and the House of Representatives that

  20. Artificial Intelligence Software for Assessing Postural Stability

    Science.gov (United States)

    Lieberman, Erez; Forth, Katharine; Paloski, William

    2013-01-01

    A software package reads and analyzes pressure distributions from sensors mounted under a person's feet. Pressure data from sensors mounted in shoes, or in a platform, can be used to provide a description of postural stability (assessing competence to deficiency) and enables the determination of the person's present activity (running, walking, squatting, falling). This package has three parts: a preprocessing algorithm for reading input from pressure sensors; a Hidden Markov Model (HMM), which is used to determine the person's present activity and level of sensing-motor competence; and a suite of graphical algorithms, which allows visual representation of the person's activity and vestibular function over time.

  1. Respostas cardiovasculares durante a postura sentada da Reeducação Postural Global (RPG Cardiovascular responses in the seated posture of the Global Postural Reeducation (GPR method

    Directory of Open Access Journals (Sweden)

    YL Mota

    2008-06-01

    Full Text Available OBJETIVO: Avaliar as respostas da freqüência cardíaca (FC, pressão arterial sistólica (PAS, diastólica (PAD, média (PAM e duplo produto (DPr, durante a postura sentada do método de Reeducação Postural Global (RPG. MATERIAIS E MÉTODOS: Nove voluntárias saudáveis (23±2,1 anos, 56,4±7,8kg, 1,61±0,05m, 21,6±2,4kg.m2-1, inexperientes na prática do método RPG, foram submetidas a uma sessão de RPG na postura sentada, realizada em três fases: repouso pré-postura, execução da postura e recuperação pós-postura. No repouso e na recuperação, as voluntárias permaneceram sentadas por 20 minutos, sendo PA e FC verificadas a cada cinco minutos. A fase de execução da postura foi realizada em três séries e mantida por três minutos cada, com intervalo de um minuto entre elas. A verificação da PA e da FC foi realizada a cada um minuto e 30 segundos de execução da postura. RESULTADOS: Os valores de PAS, PAD, PAM e DPr foram significativamente maiores (pOBJECTIVE: To evaluate heart rate (HR, systolic arterial pressure (SAP, diastolic arterial pressure (DAP, mean arterial pressure (MAP and double product (DP responses in the seated posture of the Global Postural Reeducation (GPR method. METHODS: Nine healthy female volunteers (23±2.1 years; 56.4±7.8kg; 1.61±0.05m, 21.6±2.4kg/m², without experience of the GPR, method underwent a treatment session in the seated posture. It was a three-step experiment: pre-posture resting, posture maintenance and post-posture recovery. In both the resting and the recovery step, the volunteers remained seated for 20 minutes and arterial pressure and HR were measured every five minutes. The posture maintenance step lasted for three minutes and was implemented three times with one-minute intervals between implementations. Arterial pressure and HR were measured every 1.5 minutes, while the posture was being maintained. RESULTS: The SAP, DAP, MAP and DP values were significantly greater (p<0.05 from

  2. Effects of Dyslexia on Postural Control in Adults

    Science.gov (United States)

    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…

  3. Prevalence of Common Postural Disorders Among Academic Dental Staff

    Directory of Open Access Journals (Sweden)

    Vakili

    2016-01-01

    Full Text Available Background Musculoskeletal disorders are common problems among dentists. These conditions may lead to inappropriate postures and impairment in physical and psychological function. On the other hand, poor postures and inappropriate ergonomic may result in a wide variety of musculoskeletal disorders. Objectives The aim of this study was to investigate the prevalence of common postural disorders of the spine and shoulder girdle among the dentists and possible correlations between demographic, anthropometric and occupational characteristics with these abnormal postures. Patients and Methods In a cross-sectional study, 96 dental staff including academic staff, residents and senior students of Tehran University of Medical Sciences was enrolled. Data were collected using a questionnaire and posture assessment tools such as plumb-line, checkerboard and flexible ruler. Data analysis was done with SPSS version 17. Results The prevalence of the forward head posture (FHP, rounded shoulder posture (RSP, scoliosis and hyperlordosis were reported in 85.5%, 68.8%, 18.8% and 17.3% of the participants, respectively. A significant correlation was found between gender and FHP (P = 0.04 and also scoliosis (P = 0.009. On the other hand, a significant correlation was seen between weight and hyperlordosis (P = 0.007. Conclusions Our study revealed a high prevalence of postural disorders especially FHP, RSP and scoliosis among Iranian dental staff. The female dentists were less susceptible to FHP and scoliosis.

  4. Posture and isokinetic shoulder strength in female water polo players

    African Journals Online (AJOL)

    Kathryn van Boom

    Water polo is a high-intensity intermittent aquatic sport which places large physical ... sport and involves the combination of muscle strength and ..... imbalanced upper extremity posture would negatively affect .... Influence of body position on shoulder ... Sweeting K, Mock M. Gait and posture - assessment in general practice.

  5. Mood Recognition Based on Upper Body Posture and Movement Features

    NARCIS (Netherlands)

    Thrasher, M.L.; Van der Zwaag, M. D.; Bianchi-Berthouze, N.; Westerink, J.H.D.M.

    2012-01-01

    While studying body postures in relation to mood is not a new concept, the majority of these studies rely on actors interpretations. This project investigated the temporal aspects of naturalistic body postures while users listened to mood inducing music. Video data was collected while participants l

  6. 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.

  7. 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.

  8. Wrist posture affects hand and forearm muscle stress during tapping.

    Science.gov (United States)

    Qin, Jin; Chen, Hua; Dennerlein, Jack T

    2013-11-01

    Non-neutral wrist posture is a risk factor of the musculoskeletal disorders among computer users. This study aimed to assess internal loads on hand and forearm musculature while tapping in different wrist postures. Ten healthy subjects tapped on a key switch using their index finger in four wrist postures: straight, ulnar deviated, flexed and extended. Torque at the finger and wrist joints were calculated from measured joint postures and fingertip force. Muscle stresses of the six finger muscles and four wrist muscles that balanced the calculated joint torques were estimated using a musculoskeletal model and optimization algorithm minimizing the squared sum of muscle stress. Non-neutral wrist postures resulted in greater muscle stresses than the neutral (straight) wrist posture, and the stress in the extensor muscles were greater than the flexors in all conditions. Wrist extensors stress remained higher than 4.5 N/cm² and wrist flexor stress remained below 0.5 N/cm² during tapping. The sustained high motor unit recruitment of extensors suggests a greater risk than other muscles especially in flexed wrist posture. This study demonstrated from the perspective of internal tissue loading the importance of maintaining neutral wrist posture during keying activities.

  9. A critical evaluation of the cognitive penetrability of posture

    NARCIS (Netherlands)

    Stins, J.F.; Beek, P.J.

    2012-01-01

    Abstract: Background/Study Context: Interactions between postural control and cognitive activity as evidenced by dual-tasking studies are common, and especially pronounced in the elderly. Some authors have used this finding to suggest that posture is "cognitively penetrable." Methods: The authors

  10. Posture and locomotion in the rat : Independent or interdependent development?

    NARCIS (Netherlands)

    Gramsbergen, A

    In this essay, recent research into the relation between postural control and the development of walking in the rat is reviewed. The adult-like walking pattern develops at the 15th to 16th day (P15-P16). Until this age, postural control, as indicated by EMG activity in the longissimus muscle in the

  11. Back to the Basics--Whatever Happened to Posture?

    Science.gov (United States)

    Althoff, Sally A.; And Others

    1988-01-01

    Data collected about 387 students mostly aged 18 to 34 participating in the Portland State University posture screening program revealed that, while almost 60 percent of students had postural asymmetrics, nearly half of the students were unaware of problems. Most students found the screening program valuable. (CB)

  12. Prevalence of osteoporosis increased in postmenopausal women with postural scoliosis

    Directory of Open Access Journals (Sweden)

    Maria Regina Rachmawati

    2015-12-01

    In post menopausal women with postural scoliosis found a higher incidence of osteoporosis. High endurance of erector spinae muscle lowers the risk of scoliosis. Exercise to improve posture and increase endurance of erector spinae muscle need to be done to prevent decline of BMD.

  13. Postural stability after inguinal herniorrhaphy under local infiltration anaesthesia

    DEFF Research Database (Denmark)

    Persson, F; Kristensen, Billy Bjarne; Lund, Claus;

    2001-01-01

    with polypropylene mesh repair (Prolene). Measurement of postural stability before operation and 30 and 60 minutes afterwards using the "Basic Balance Master" system, and balance assessed by visual analogue scale and verbal rating scale. MAIN OUTCOME MEASURES: Postural stability and subjectively assessed balance...

  14. 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 varian

  15. Group Rapport: Posture Sharing as a Nonverbal Indicator

    Science.gov (United States)

    LaFrance, Marianne; Broadbent, Maida

    1976-01-01

    Systematic observation and a questionnaire format were used to investigate the relationship between posture sharing and self-report indications of rapport in a group situation--college seminar classrooms. The greater the amount of mirroring and congruent postures evidenced by students vis-a-vis the teacher, the higher the ratings of involvement.…

  16. Development of postural control - Differences between ventral and dorsal muscles?

    NARCIS (Netherlands)

    Hadders-Algra, M; Brogren, E; Forssberg, H

    Postural control is organized in basic, direction specific synergies which can be adapted to task-related conditions. Studies on the development of postural adjustments in young sitting children revealed that largely variable, direction specific muscle activation patterns are already present in 5-6

  17. Selection and control of limb posture for stability

    NARCIS (Netherlands)

    Franklin, D.W.; Selen, L.P.J.; Franklin, S.; Wolpert, D.M.

    2013-01-01

    Impedance control can be used to stabilize the limb against both instability and unpredictable perturbations. Limb posture influences motor noise, energy usage and limb impedance as well as their interaction. Here we examine whether subjects use limb posture as part of a mechanism to regulate limb s

  18. Development of postural control - Differences between ventral and dorsal muscles?

    NARCIS (Netherlands)

    Hadders-Algra, M; Brogren, E; Forssberg, H

    1998-01-01

    Postural control is organized in basic, direction specific synergies which can be adapted to task-related conditions. Studies on the development of postural adjustments in young sitting children revealed that largely variable, direction specific muscle activation patterns are already present in 5-6

  19. Oculomotor tasks affect differently postural control in healthy children.

    Science.gov (United States)

    Bucci, Maria Pia; Ajrezo, Layla; Wiener-Vacher, Sylvette

    2015-11-01

    Eye movements affect postural stability in children. The present study focuses on the effect of different types of eye movements on postural stability in healthy children. Both eye movements and postural stability have been recorded in 51 healthy children from 6.3 to 15.5 years old. Eye movements were recorded binocularly with a video oculography (MobilEBT(®)), and postural stability was measured while child was standing on a force platform (TechnoConcept(®)). Children performed three oculomotor tasks: saccades, pursuits and reading a text silently. We measured the number of saccades made in the three oculomotor tasks, the number of words read, and the surface area, the length and mean velocity of the center of pressure (CoP). According to previous studies, postural control improves with age until 10-12 years. Saccades toward a target as well as during a reading task reduce significantly the CoP displacement and its velocity, while during pursuit eye movements all children increase postural parameters (i.e., the surface area, the length and mean velocity of the CoP). These results suggest the presence of an interaction between the oculomotor control and the postural system. Visual attention to perform saccades (to stationary targets or to words) influences postural stability more than the frequency of saccade triggering does.

  20. Static Postural Stability Is Normal in Dyslexic Children.

    Science.gov (United States)

    Brown, Brian; And Others

    1985-01-01

    An experiment on 15 dyslexic and 23 carefully matched control subjects (10- to 12-year-old males), examining their ability to maintain standing posture with eyes open and closed and with standard and tandem foot placement, revealed no differences under any condition tested and no differences in use of visual information to maintain their posture.…

  1. 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…

  2. The final common pathway in postural control - Developmental perspective

    NARCIS (Netherlands)

    Kernell, D

    1998-01-01

    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 high

  3. Posture and locomotion in the rat : Independent or interdependent development?

    NARCIS (Netherlands)

    Gramsbergen, A

    1998-01-01

    In this essay, recent research into the relation between postural control and the development of walking in the rat is reviewed. The adult-like walking pattern develops at the 15th to 16th day (P15-P16). Until this age, postural control, as indicated by EMG activity in the longissimus muscle in the

  4. Postural Strategies in Prader-Willi and Down Syndrome Patients

    Science.gov (United States)

    Cimolin, Veronica; Galli, Manuela; Grugni, Graziano; Vismara, Luca; Precilios, Helmer; Albertini, Giorgio; Rigoldi, Chiara; Capodaglio, Paolo

    2011-01-01

    Patients affected by Down (DS) and Prader-Willi syndrome (PWS) are characterised by some common clinical and functional features including gait disorders and reduced postural control. The aim of our study was to quantitatively compare postural control in adult PWS and DS. We studied 12 PWS and 19 DS adult patients matched for age, height, weight…

  5. 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.

  6. Assessing combined exposures of whole-body vibration and awkward posture--further results from application of a simultaneous field measurement methodology.

    Science.gov (United States)

    Raffler, Nastaran; Hermanns, Ingo; Sayn, Detlef; Göres, Benno; Ellegast, Rolf; Rissler, Jörg

    2010-01-01

    The drivers of ten vehicles (tram, helicopter, saloon car, van, forklift, two mobile excavators, wheel loader, tractor, elevating platform truck) were studied with regard to the combined exposures of whole-body vibration and awkward posture during occupational tasks. Seven degrees of freedom (DOFs), or body angles, were recorded as a function of time by means of the CUELA measuring system (Computer-assisted registration and long-term analysis of musculoskeletal workloads) for the purpose of posture assessment. The vibrational exposure is expressed as the vector sum of the frequency-weighted accelerations in the three Cartesian coordinates; these were recorded simultaneously with the posture measurement. Based upon the percentage of working time spent under different workloads, a scheme is proposed for classification of the two exposures into three categories. In addition, a risk of adverse health effects classified as low, possible or high can be assigned to the combination of the two exposures. With regard to posture, the most severe exposure was measured for the drivers of the wheel loader and for the tractor driver, whereas the lowest exposure was measured for the helicopter pilots and van drivers. With regard to the combination of whole-body and posture exposures, the tractor driver and the elevating platform truck driver exhibited the highest workloads.

  7. Pelvic morphology, body posture and standing balance characteristics of adolescent able-bodied and idiopathic scoliosis girls.

    Directory of Open Access Journals (Sweden)

    Georgios A Stylianides

    Full Text Available The purpose of this study was to determine how pelvic morphology, body posture, and standing balance variables of scoliotic girls differ from those of able-bodied girls, and to classify neuro-biomechanical variables in terms of a lower number of unobserved variables. Twenty-eight scoliotic and twenty-five non-scoliotic able-bodied girls participated in this study. 3D coordinates of ten anatomic body landmarks were used to describe pelvic morphology and trunk posture using a Flock of Birds system. Standing balance was measured using a force plate to identify the center of pressure (COP, and its anteroposterior (AP and mediolateral (ML displacements. A multivariate analysis of variance (MANOVA was performed to determine differences between the two groups. A factor analysis was used to identify factors that best describe both groups. Statistical differences were identified between the groups for each of the parameter types. While spatial orientation of the pelvis was similar in both groups, five of the eight trunk postural variables of the scoliotic group were significantly different that the able-bodied group. Also, five out of the seven standing balance variables were higher in the scoliotic girls. Approximately 60% of the variation is supported by 4 factors that can be associated with a set of variables; standing balance variables (factor 1, body posture variables (factor 2, and pelvic morphology variables (factors 3 and 4. Pelvic distortion, body posture asymmetry, and standing imbalance are more pronounced in scoliotic girls, when compared to able-bodied girls. These findings may be beneficial when addressing balance and ankle proprioception exercises for the scoliotic population.

  8. Relationship between posterior crossbite and postural alterations in children

    Directory of Open Access Journals (Sweden)

    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.

  9. Ergonomic intervention for improving work postures during notebook computer operation.

    Science.gov (United States)

    Jamjumrus, Nuchrawee; Nanthavanij, Suebsak

    2008-06-01

    This paper discusses the application of analytical algorithms to determine necessary adjustments for operating notebook computers (NBCs) and workstations so that NBC users can assume correct work postures during NBC operation. Twenty-two NBC users (eleven males and eleven females) were asked to operate their NBCs according to their normal work practice. Photographs of their work postures were taken and analyzed using the Rapid Upper Limb Assessment (RULA) technique. The algorithms were then employed to determine recommended adjustments for their NBCs and workstations. After implementing the necessary adjustments, the NBC users were then re-seated at their workstations, and photographs of their work postures were re-taken, to perform the posture analysis. The results show that the NBC users' work postures are improved when their NBCs and workstations are adjusted according to the recommendations. The effectiveness of ergonomic intervention is verified both visually and objectively.

  10. Clinical working postures of bachelor of oral health students.

    Science.gov (United States)

    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.

  11. Posture Detection Based on Smart Cushion for Wheelchair Users

    Directory of Open Access Journals (Sweden)

    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.

  12. Self versus environment motion in postural control.

    Directory of Open Access Journals (Sweden)

    Kalpana Dokka

    2010-02-01

    Full Text Available To stabilize our position in space we use visual information as well as non-visual physical motion cues. However, visual cues can be ambiguous: visually perceived motion may be caused by self-movement, movement of the environment, or both. The nervous system must combine the ambiguous visual cues with noisy physical motion cues to resolve this ambiguity and control our body posture. Here we have developed a Bayesian model that formalizes how the nervous system could solve this problem. In this model, the nervous system combines the sensory cues to estimate the movement of the body. We analytically demonstrate that, as long as visual stimulation is fast in comparison to the uncertainty in our perception of body movement, the optimal strategy is to weight visually perceived movement velocities proportional to a power law. We find that this model accounts for the nonlinear influence of experimentally induced visual motion on human postural behavior both in our data and in previously published results.

  13. Fitts' Law in early postural adjustments.

    Science.gov (United States)

    Bertucco, M; Cesari, P; Latash, M L

    2013-02-12

    We tested a hypothesis that the classical relation between movement time and index of difficulty (ID) in quick pointing action (Fitts' Law) reflects processes at the level of motor planning. Healthy subjects stood on a force platform and performed quick and accurate hand movements into targets of different size located at two distances. The movements were associated with early postural adjustments that are assumed to reflect motor planning processes. The short distance did not require trunk rotation, while the long distance did. As a result, movements over the long distance were associated with substantial Coriolis forces. Movement kinematics and contact forces and moments recorded by the platform were studied. Movement time scaled with ID for both movements. However, the data could not be fitted with a single regression: Movements over the long distance had a larger intercept corresponding to movement times about 140 ms longer than movements over the shorter distance. The magnitude of postural adjustments prior to movement initiation scaled with ID for both short and long distances. Our results provide strong support for the hypothesis that Fitts' Law emerges at the level of motor planning, not at the level of corrections of ongoing movements. They show that, during natural movements, changes in movement distance may lead to changes in the relation between movement time and ID, for example when the contribution of different body segments to the movement varies and when the action of Coriolis force may require an additional correction of the movement trajectory. Published by Elsevier Ltd.

  14. Viscoelastic properties of laryngeal posturing muscles

    Science.gov (United States)

    Alipour, Fariborz; Hunter, Eric; Titze, Ingo

    2003-10-01

    Viscoelastic properties of canine laryngeal muscles were measured in a series of in vitro experiments. Laryngeal posturing that controls vocal fold length and adduction/abduction is an essential component of the voice production. The dynamics of posturing depends on the viscoelastic and physiological properties of the laryngeal muscles. The time-dependent and nonlinear behaviors of these tissues are also crucial in the voice production and pitch control theories. The lack of information on some of these muscles such as posterior cricoarytenoid muscle (PCA), lateral cricoarytenoid muscle (LCA), and intraarytenoid muscle (IA) was the major incentive for this study. Samples of PCA and LCA muscles were made from canine larynges and mounted on a dual-servo system (Ergometer) as described in our previous works. Two sets of experiments were conducted on each muscle, a 1-Hz stretch and release experiment that provides stress-strain data and a stress relaxation test. Data from these muscles were fitted to viscoelastic models and Young's modulus and viscoelastic constants are obtained for each muscle. Preliminary data indicates that elastics properties of these muscles are similar to those of thyroarytenoid and cricothyroid muscles. The relaxation response of these muscles also shows some similarity to other laryngeal muscles in terms of time constants.

  15. Postural Tachycardia Syndrome: Beyond Orthostatic Intolerance.

    Science.gov (United States)

    Garland, Emily M; Celedonio, Jorge E; Raj, Satish R

    2015-09-01

    Postural tachycardia syndrome (POTS) is a form of chronic orthostatic intolerance for which the hallmark physiological trait is an excessive increase in heart rate with assumption of upright posture. The orthostatic tachycardia occurs in the absence of orthostatic hypotension and is associated with a >6-month history of symptoms that are relieved by recumbence. The heart rate abnormality and orthostatic symptoms should not be caused by medications that impair autonomic regulation or by debilitating disorders that can cause tachycardia. POTS is a "final common pathway" for a number of overlapping pathophysiologies, including an autonomic neuropathy in the lower body, hypovolemia, elevated sympathetic tone, mast cell activation, deconditioning, and autoantibodies. Not only may patients be affected by more than one of these pathophysiologies but also the phenotype of POTS has similarities to a number of other disorders, e.g., chronic fatigue syndrome, Ehlers-Danlos syndrome, vasovagal syncope, and inappropriate sinus tachycardia. POTS can be treated with a combination of non-pharmacological approaches, a structured exercise training program, and often some pharmacological support.

  16. Characterizing traits of coordination

    NARCIS (Netherlands)

    Poss, R.

    2013-01-01

    How can one recognize coordination languages and technologies? As this report shows, the common approach that contrasts coordination with computation is intellectually unsound: depending on the selected understanding of the word "computation", it either captures too many or too few programming

  17. Coordination models and languages

    NARCIS (Netherlands)

    Papadopoulos, G.A.; Arbab, F.

    1998-01-01

    A new class of models, formalisms and mechanisms has recently evolved for describing concurrent and distributed computations based on the concept of ``coordination''. The purpose of a coordination model and associated language is to provide a means of integrating a number of possibly heterogeneous c

  18. Team coordination dynamics.

    Science.gov (United States)

    Gorman, Jamie C; Amazeen, Polemnia G; Cooke, Nancy J

    2010-07-01

    Team coordination consists of both the dynamics of team member interaction and the environmental dynamics to which a team is subjected. Focusing on dynamics, an approach is developed that contrasts with traditional aggregate-static concepts of team coordination as characterized by the shared mental model approach. A team coordination order parameter was developed to capture momentary fluctuations in coordination. Team coordination was observed in three-person uninhabited air vehicle teams across two experimental sessions. The dynamics of the order parameter were observed under changes of a team familiarity control parameter. Team members returned for the second session to either the same (Intact) or different (Mixed) team. 'Roadblock' perturbations, or novel changes in the task environment, were introduced in order to probe the stability of team coordination. Nonlinear dynamic methods revealed differences that a traditional approach did not: Intact and Mixed team coordination dynamics looked very different; Mixed teams were more stable than Intact teams and explored the space of solutions without the need for correction. Stability was positively correlated with the number of roadblock perturbations that were overcome successfully. The novel and non-intuitive contribution of a dynamical analysis was that Mixed teams, who did not have a long history working together, were more adaptive. Team coordination dynamics carries new implications for traditional problems such as training adaptive teams.

  19. Coordinate measuring machines

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceability...

  20. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Ghai S

    2017-03-01

    Full Text Available Shashank Ghai,1,2 Ishan Ghai,3 Alfred O Effenberg1 1Institute of Sports Science, Leibniz University, Hannover, Germany; 2Department of Sports Science, University of Waikato, Hamilton, New Zealand; 3School of Engineering & Life Sciences, Jacobs University, Bremen, Germany Abstract: The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review’s inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16–2.10 and in patients suffering from chronic stroke (-0.22 to 0.86. The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (-0.74 to 0

  1. Effect of seated trunk posture on eye blink startle and subjective experience: comparing flexion, neutral upright posture, and extension of spine.

    Directory of Open Access Journals (Sweden)

    Erik Ceunen

    Full Text Available Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched, neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes.

  2. Effect of seated trunk posture on eye blink startle and subjective experience: comparing flexion, neutral upright posture, and extension of spine.

    Science.gov (United States)

    Ceunen, Erik; Zaman, Jonas; Vlaeyen, Johan W S; Dankaerts, Wim; Van Diest, Ilse

    2014-01-01

    Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Trunk postures and peak and cumulative low back kinetics during upright posture sheep shearing.

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    Gregory, Diane E; Laughton, Carla; Carman, Allan; Milosavljevic, Stephan; Callaghan, Jack P

    2009-12-01

    Sheep shearing is the most demanding occupation in the wool harvesting industry and is known to have a high prevalence of low back pain. While use of a commercially available trunk harness reduces load on the low back, the extreme trunk flexion associated with shearing still remains. A novel, upright posture shearing technique has been designed to allow a more neutral spine posture. This study assessed this upright technique and found significant reductions in both trunk flexion and cumulative low back loading when compared to either the traditional method or the use of the trunk harness. Moments about the shoulder tended to be higher while using the upright shearing technique and further investigation of shoulder kinetics will be required to assess whether this creates injury risk to the upper extremity. Despite increased shoulder moments, the reduction in flexion and cumulative loading with the use of the upright technique has the potential to reduce risk of low back pain among shearers.

  5. Newly standing infants increase postural stability when performing a supra-postural task.

    Directory of Open Access Journals (Sweden)

    Laura J Claxton

    Full Text Available Independent stance is one of the most difficult motor milestones to achieve. Newly standing infants exhibit exaggerated body movements and can only stand for a brief amount of time. Given the difficult nature of bipedal stance, these unstable characteristics are slow to improve. However, we demonstrate that infants can increase their stability when engaged in a standing goal-directed task. Infants' balance was measured while standing and while standing and holding a visually attractive toy. When holding the toy, infants stood for a longer period of time, exhibited less body sway, and more mature postural dynamics. These results demonstrate that even with limited standing experience, infants can stabilize posture to facilitate performance of a concurrent task.

  6. Sensorimotor integration in human postural control

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    Peterka, R. J.

    2002-01-01

    It is generally accepted that human bipedal upright stance is achieved by feedback mechanisms that generate an appropriate corrective torque based on body-sway motion detected primarily by visual, vestibular, and proprioceptive sensory systems. Because orientation information from the various senses is not always available (eyes closed) or accurate (compliant support surface), the postural control system must somehow adjust to maintain stance in a wide variety of environmental conditions. This is the sensorimotor integration problem that we investigated by evoking anterior-posterior (AP) body sway using pseudorandom rotation of the visual surround and/or support surface (amplitudes 0.5-8 degrees ) in both normal subjects and subjects with severe bilateral vestibular loss (VL). AP rotation of body center-of-mass (COM) was measured in response to six conditions offering different combinations of available sensory information. Stimulus-response data were analyzed using spectral analysis to compute transfer functions and coherence functions over a frequency range from 0.017 to 2.23 Hz. Stimulus-response data were quite linear for any given condition and amplitude. However, overall behavior in normal subjects was nonlinear because gain decreased and phase functions sometimes changed with increasing stimulus amplitude. "Sensory channel reweighting" could account for this nonlinear behavior with subjects showing increasing reliance on vestibular cues as stimulus amplitudes increased. VL subjects could not perform this reweighting, and their stimulus-response behavior remained quite linear. Transfer function curve fits based on a simple feedback control model provided estimates of postural stiffness, damping, and feedback time delay. There were only small changes in these parameters with increasing visual stimulus amplitude. However, stiffness increased as much as 60% with increasing support surface amplitude. To maintain postural stability and avoid resonant behavior, an

  7. Correlation dimension estimates of human postural sway.

    Science.gov (United States)

    Gurses, Senih; Celik, Huseyin

    2013-02-01

    Human postural sway during quiet standing demonstrates a complex structured dynamics, which has been studied by applying numerous methods, such as linear system identification methods, stochastic analysis, and nonlinear system dynamics tools. Although each of the methods applied revealed some particular features of the sway data none of them have succeeded to present a global picture of the quiet stance dynamics, which probably has both stochastic and deterministic properties. In this study we have started applying ergodic theory of dynamical systems to explore statistical characteristic of the sway dynamics observed in successive trials of a subject, different subjects in an age group, and finally different age groups constituted by children, adults, and elderly subjects. Five successive 180-s long trials were performed by each of 28 subjects in four age groups at quiet stance with eyes open. Stationary and ergodic signal characteristics of five successive center of pressure time series collected from a subject in antero-posterior direction (CoPx) were examined. 97% of the trials were found to be stationary by applying Run Test while children and elderly groups demonstrated significant nonstationary behavior. On the other hand 13 out of 24 subjects were found to be nonergodic. We expected to observe differences in complexity of CoPx dynamics due to aging (Farmer, Ott, & Yorke, 1983). However linear metrics such as standard deviation and Fourier spectra of CoPx signals did not show differences due to the age groups. Correlation dimension (Dk) estimates of stationary CoPx signals being an invariant measure of nonlinear system dynamics were computed by using the average displacement method (Eckmann & Ruelle, 1985). Postural dynamics was expanded in m-dimensional space through CoPx signal by introducing optimum time delays, τcritical. 112 out of 136 stationary CoPx signals for 24 stationary subjects converged to Dk estimates. Average of Dk estimates for children and

  8. Hemodynamic response to the upright posture.

    Science.gov (United States)

    Smith, J J; Porth, C M; Erickson, M

    1994-05-01

    The authors' objective was to review previous studies of immediate (first 30 seconds) and stabilized (30 seconds to 20 minutes) hemodynamic responses of healthy adults to the head-up posture, with particular reference to alteration of such responses in the elderly and the usefulness of such data in the diagnosis of orthostatic hypotension. The immediate response in healthy young adults is characterized by a prompt rise in heart rate, which peaks at about 8 to 15 seconds and then tapers; the arterial pressure and total vascular resistance decrease sharply at 5 to 10 seconds, followed by a rapid rebound and overshoot. Over the first 30 seconds there is a steady parallel decline of thoracic blood volume and stroke volume; there is also an initial surge of cardiac output followed by a steady decrease. During the stabilized response (30 seconds to 20 minutes), the hemodynamic variables are relatively steady, showing average increases in heart rate of about 15 to 30%, in diastolic pressure of 10 to 15%, and in total vascular resistance of 30 to 40%; during the 5th to 20th minutes there are also decreases in thoracic blood volume averaging about 25 to 30%, in cardiac output 15 to 30%, and in pulse pressure about 5 to 10%. It is evident that in normal human subjects, assumption of the upright posture results in profound hemodynamic changes, most of them occurring during the first 30 seconds. In elderly subjects (aged 60-69 years), there are, in the upright posture, lesser increments of heart rate and diastolic pressure, but no significant differences from younger age groups in the response of thoracic blood volume, cardiac output or total vascular resistance. However, beginning at about age 75, there is an increasing incidence of orthostatic hypotension, which averages about 14 to 20% at age 75 and older. The tendency toward orthostatic hypotension in the elderly is due (1) to the structural and functional changes in the circulation itself, (2) to a decline in autonomic

  9. Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults.

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    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.

  10. Postural orientation in microgravity depends on straightening up movement performed

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    Vaugoyeau, Marianne; Assaiante, Christine

    2009-08-01

    Whether the vertical body orientation depends on the initial posture and/or the type of straightening up movement is the main question raised in this paper. Another objective was to specify the compensatory role of visual input while adopting an erected posture during microgravity. The final body orientation was analysed in microgravity during parabolic flights. After either (1) straightening up movement from a crouching or (2) a sitting posture, with and without vision. The main results are the following: (1) a vertical erected final posture is correctly achieved after sit to stand movement, whereas all subjects were tilted forward after straightening up from a crouching posture and (2) vision may contribute to correct final posture. These results suggest the existence of a re-weighting of the remaining sensory information, visual information, contact cutaneous cues and proprioceptive information under microgravity condition. We can put forward the alternative hypothesis that the control of body orientation under microgravity condition may also be achieved on the basis of a postural body scheme, that seems to be dependant on the type of movement and/ or the initial position of the whole body.

  11. Emotional and movement-related body postures modulate visual processing.

    Science.gov (United States)

    Borhani, Khatereh; Làdavas, Elisabetta; Maier, Martin E; Avenanti, Alessio; Bertini, Caterina

    2015-08-01

    Human body postures convey useful information for understanding others' emotions and intentions. To investigate at which stage of visual processing emotional and movement-related information conveyed by bodies is discriminated, we examined event-related potentials elicited by laterally presented images of bodies with static postures and implied-motion body images with neutral, fearful or happy expressions. At the early stage of visual structural encoding (N190), we found a difference in the sensitivity of the two hemispheres to observed body postures. Specifically, the right hemisphere showed a N190 modulation both for the motion content (i.e. all the observed postures implying body movements elicited greater N190 amplitudes compared with static postures) and for the emotional content (i.e. fearful postures elicited the largest N190 amplitude), while the left hemisphere showed a modulation only for the motion content. In contrast, at a later stage of perceptual representation, reflecting selective attention to salient stimuli, an increased early posterior negativity was observed for fearful stimuli in both hemispheres, suggesting an enhanced processing of motivationally relevant stimuli. The observed modulations, both at the early stage of structural encoding and at the later processing stage, suggest the existence of a specialized perceptual mechanism tuned to emotion- and action-related information conveyed by human body postures. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  12. Global body posture evaluation in patients with temporomandibular joint disorder

    Directory of Open Access Journals (Sweden)

    Eliza Tiemi Saito

    2009-01-01

    Full Text Available AIM: To identify the relationship between anterior disc displacement and global posture (plantar arches, lower limbs, shoulder and pelvic girdle, vertebral spine, head and mandibles. Common signs and symptoms of anterior disc displacement were also identified. INTRODUCTION: Global posture deviations cause body adaptation and realignment, which may interfere with the organization and function of the temporomandibular joint. METHODS: Global posture evaluation was performed in a group of 10 female patients (20 to 30 years of age with temporomandibular joint disc displacement and in a control group of 16 healthy female volunteers matched for age, weight and height. Anterior disc displacement signs, symptoms and the presence of parafunctional habits were also identified through interview. RESULTS: Patients with disc displacement showed a higher incidence of pain in the temporomandibular joint area, but there were no differences in parafunctional habits between the groups. In the disc displacement group, postural deviations were found in the pelvis (posterior rotation, lumbar spine (hyperlordosis, thoracic spine (rectification, head (deviation to the right and mandibles (deviation to the left with open mouth. There were no differences in the longitudinal plantar arches between the groups. CONCLUSION: Our results suggest a close relationship between body posture and temporomandibular disorder, though it is not possible to determine whether postural deviations are the cause or the result of the disorder. Hence, postural evaluation could be an important component in the overall approach to providing accurate prevention and treatment in the management of patients with temporomandibular disorder.

  13. Patterns of postural sway in high anxious children

    Directory of Open Access Journals (Sweden)

    van Dokkum Elisabeth H

    2009-10-01

    Full Text Available Abstract Background Current research suggests that elevated levels of anxiety have a negative impact on the regulation of balance. However, most studies to date examined only global balance performance, with little attention to the way body posture is organized in space and time. The aim of this study is to examine whether posturographic measures can reveal (subclinical balance deficits in children with high levels of anxiety. Methods We examined the spatio-temporal structure of the centre-of-pressure (COP fluctuations in children with elevated levels of anxiety and a group of typically developing children while maintaining quiet stance on a force plate in various balance challenging conditions. Balance was challenged by adopting sensory manipulations (standing with eyes closed and/or standing on a foam surface and using a cognitive manipulation (dual-tasking. Results Across groups, postural performance was strongly influenced by the sensory manipulations, and hardly by the cognitive manipulation. We also found that children with anxiety had overall more postural sway, and that their postural sway was overall less complex than sway of typically developing children. The postural differences between groups were present even in the simple baseline condition, and the group differences became larger with increasing task difficulty. Conclusion The pattern of postural sway suggests that balance is overall less stable and more attention demanding in children with anxiety than typically developing children. The findings provide further evidence for a neuro-behavioral link between psychopathology and the effectiveness of postural control.

  14. Postural disorders in mouth breathing children: a systematic review.

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    Neiva, Patricia Dayrell; Kirkwood, Renata Noce; Mendes, Polyana Leite; Zabjek, Karl; Becker, Helena Gonçalves; Mathur, Sunita

    2017-07-05

    Mouth breathing syndrome can cause sleep disturbances that compromise the performance of children in school. It might also cause postural abnormalities involving the head and cervical spine; however, the association between postural abnormalities and mouth breathing in children is unclear. To assess the methodological quality of studies and determine if there is an association between mouth breathing and postural disorders in children. Databases comprised MEDLINE, CINAHL, PEDro, LILACS, EMBASE and Cochrane Central Registrar of Controlled Trials. Searches were until March 2016 and included studies that evaluated postural disorders in children diagnosed with mouth breathing. The Downs and Black checklist was used to evaluate the quality of the evidences. Ten studies were included totaling 417 children from 5 to 14 years. Two studies used the New York State Postural Rating Scale, seven used photography and one used motion capture to measure posture. The methods used to analyze the data included the Postural Analysis Software (SAPO), Fisiometer, ALCimagem and routines in MATLAB program. Quality assessment resulted in low scores (Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  15. 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.

  16. PENINGKATAN STABILITAS POSTURAL PADA LANSIA MELALUI BALANCE EXERCISE

    Directory of Open Access Journals (Sweden)

    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.

  17. The role of anticipatory postural adjustments in compensatory control of posture: 2. Biomechanical analysis.

    Science.gov (United States)

    Santos, Marcio J; Kanekar, Neeta; Aruin, Alexander S

    2010-06-01

    The central nervous system (CNS) utilizes anticipatory (APAs) and compensatory (CPAs) postural adjustments to maintain equilibrium while standing. It is known that these postural adjustments involve displacements of the center of mass (COM) and center of pressure (COP). The purpose of the study was to investigate the relationship between APAs and CPAs from a kinetic and kinematic perspective. Eight subjects were exposed to external predictable and unpredictable perturbations induced at the shoulder level while standing. Kinematic and kinetic data were recorded and analyzed during the time duration typical for anticipatory and compensatory postural adjustments. When the perturbations were unpredictable, the COM and COP displacements were larger compared to predictable conditions with APAs. Thus, the peak of COM displacement, after the pendulum impact, in the posterior direction reached 28+/-9.6mm in the unpredictable conditions with no APAs whereas it was 1.6 times smaller, reaching 17+/-5.5mm during predictable perturbations. Similarly, after the impact, the peak of COP displacement in the posterior direction was 60+/-14 mm for unpredictable conditions and 28+/-3.6mm for predictable conditions. Finally, the times of the peak COM and COP displacements were similar in the predictable and unpredictable conditions. This outcome provides additional knowledge about how body balance is controlled in presence and in absence of information about the forthcoming perturbation. Moreover, it suggests that control of posture could be enhanced by better utilization of APAs and such an approach could be considered as a valuable modality in the rehabilitation of individuals with balance impairment.

  18. Uranyl ion coordination

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    Evans, H.T.

    1963-01-01

    A review of the known crystal structures containing the uranyl ion shows that plane-pentagon coordination is equally as prevalent as plane-square or plane-hexagon. It is suggested that puckered-hexagon configurations of OH - or H2O about the uranyl group will tend to revert to plane-pentagon coordination. The concept of pentagonal coordination is invoked for possible explanations of the complex crystallography of the natural uranyl hydroxides and the unusual behavior of polynuclear ions in hydrolyzed uranyl solutions.

  19. Contribution of supraspinal systems to generation of automatic postural responses

    Directory of Open Access Journals (Sweden)

    Tatiana G Deliagina

    2014-10-01

    Full Text Available Different species maintain a particular body orientation in space due to activity of the closed-loop postural control system. In this review we discuss the role of neurons of descending pathways in operation of this system as revealed in animal models of differing complexity: lower vertebrate (lamprey and higher vertebrates (rabbit and cat.In the lamprey and quadruped mammals, the role of spinal and supraspinal mechanisms in the control of posture is different. In the lamprey, the system contains one closed-loop mechanism consisting of supraspino-spinal networks. Reticulospinal (RS neurons play a key role in generation of postural corrections. Due to vestibular input, any deviation from the stabilized body orientation leads to activation of a specific population of RS neurons. Each of the neurons activates a specific motor synergy. Collectively, these neurons evoke the motor output necessary for the postural correction. In contrast to lampreys, postural corrections in quadrupeds are primarily based not on the vestibular input but on the somatosensory input from limb mechanoreceptors. The system contains two closed-loop mechanisms – spinal and spino-supraspinal networks, which supplement each other. Spinal networks receive somatosensory input from the limb signaling postural perturbations, and generate spinal postural limb reflexes. These reflexes are relatively weak, but in intact animals they are enhanced due to both tonic supraspinal drive and phasic supraspinal commands. Recent studies of these supraspinal influences are considered in this review. A hypothesis suggesting common principles of operation of the postural systems stabilizing body orientation in a particular plane in the lamprey and quadrupeds, that is interaction of antagonistic postural reflexes, is discussed.

  20. Contribution of supraspinal systems to generation of automatic postural responses.

    Science.gov (United States)

    Deliagina, Tatiana G; Beloozerova, Irina N; Orlovsky, Grigori N; Zelenin, Pavel V

    2014-01-01

    Different species maintain a particular body orientation in space due to activity of the closed-loop postural control system. In this review we discuss the role of neurons of descending pathways in operation of this system as revealed in animal models of differing complexity: lower vertebrate (lamprey) and higher vertebrates (rabbit and cat). In the lamprey and quadruped mammals, the role of spinal and supraspinal mechanisms in the control of posture is different. In the lamprey, the system contains one closed-loop mechanism consisting of supraspino-spinal networks. Reticulospinal (RS) neurons play a key role in generation of postural corrections. Due to vestibular input, any deviation from the stabilized body orientation leads to activation of a specific population of RS neurons. Each of the neurons activates a specific motor synergy. Collectively, these neurons evoke the motor output necessary for the postural correction. In contrast to lampreys, postural corrections in quadrupeds are primarily based not on the vestibular input but on the somatosensory input from limb mechanoreceptors. The system contains two closed-loop mechanisms - spinal and spino-supraspinal networks, which supplement each other. Spinal networks receive somatosensory input from the limb signaling postural perturbations, and generate spinal postural limb reflexes. These reflexes are relatively weak, but in intact animals they are enhanced due to both tonic supraspinal drive and phasic supraspinal commands. Recent studies of these supraspinal influences are considered in this review. A hypothesis suggesting common principles of operation of the postural systems stabilizing body orientation in a particular plane in the lamprey and quadrupeds, that is interaction of antagonistic postural reflexes, is discussed.

  1. Jump Rope Training: Balance and Motor Coordination in Preadolescent Soccer Players.

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    Trecroci, Athos; Cavaggioni, Luca; Caccia, Riccardo; Alberti, Giampietro

    2015-12-01

    Harre Circuit Test associated with jump rope training can potentially be attributed to an enhancement of the inter-limb coordination and SSC ability.Results from the present study indicate that young soccer players should be encouraged to practice general physical activities together with sport-specific exercise during their training sessions.

  2. Body temperatures and associated postures of the zebra-tailed lizard, Callisaurus draconoides

    Energy Technology Data Exchange (ETDEWEB)

    Muth, A.

    1977-01-01

    Body temperature and associated postures of the zebra-tailed lizard, Callisaurus draconoides, were examined in the field and laboratory. Three distinct postures are described: prostrate, tail-down and elevated. The mean body temperatures of the respective postures in the field were: 33.9, 40.5 and 42.7 C. In the laboratory, heating rates were greatest for the prostrate posture and least for the elevated posture. Body temperatures and heating rates are significantly correlated with posture. These correlations suggest that the postures are associated with behavioral thermoregulation in the field.

  3. Prephonatory chest wall posturing in stutterers.

    Science.gov (United States)

    Baken, R J; McManus, D A; Cavallo, S A

    1983-09-01

    The possibility that prephonatory chest wall posturing is abnormal in stutterers was explored by observing rib cage and abdominal hemicircumference changes during the interval between the presentation of a stimulus and the production of/alpha/by a group of stutterers (N = 5). It was found that the patterns of chest wall adjustment for phonation were qualitatively identical in the stutterers and in a comparable group of normal men studied previously. There was, however, a significant difference in the way in which lung volume changed during the execution of the chest wall adjustment. This was considered to be indicative of delayed glottal closure among the stutterers rather than representative of a primary ventilatory disturbance.

  4. A Methodology for Investigating Adaptive Postural Control

    Science.gov (United States)

    McDonald, P. V.; Riccio, G. E.

    1999-01-01

    Our research on postural control and human-environment interactions provides an appropriate scientific foundation for understanding the skill of mass handling by astronauts in weightless conditions (e.g., extravehicular activity or EVA). We conducted an investigation of such skills in NASA's principal mass-handling simulator, the Precision Air-Bearing Floor, at the Johnson Space Center. We have studied skilled movement-body within a multidisciplinary context that draws on concepts and methods from biological and behavioral sciences (e.g., psychology, kinesiology and neurophysiology) as well as bioengineering. Our multidisciplinary research has led to the development of measures, for manual interactions between individuals and the substantial environment, that plausibly are observable by human sensory systems. We consider these methods to be the most important general contribution of our EVA investigation. We describe our perspective as control theoretic because it draws more on fundamental concepts about control systems in engineering than it does on working constructs from the subdisciplines of biomechanics and motor control in the bio-behavioral sciences. At the same time, we have attempted to identify the theoretical underpinnings of control-systems engineering that are most relevant to control by human beings. We believe that these underpinnings are implicit in the assumptions that cut across diverse methods in control-systems engineering, especially the various methods associated with "nonlinear control", "fuzzy control," and "adaptive control" in engineering. Our methods are based on these theoretical foundations rather than on the mathematical formalisms that are associated with particular methods in control-systems engineering. The most important aspects of the human-environment interaction in our investigation of mass handling are the functional consequences that body configuration and stability have for the pick up of information or the achievement of

  5. Effects of wheelchair posture on patient safety.

    Science.gov (United States)

    Gavin-Dreschnack, Deborah

    2004-01-01

    Wheelchairs originally were designed to transport people from one place to another quickly and easily. They have evolved to rank among the most important therapeutic devices used in rehabilitation. Currently, an estimated 2.2 million people who use wheelchairs generally are living longer and moving about more. However, the increased use of wheelchairs has been accompanied by many types of adverse events and repetitive stress injuries. Wheelchair prescription, posture, training, and maintenance are critical components of safety in this population, and may be enhanced through increased awareness and education. Since nurses and nursing staff are most often involved directly with wheelchair users (particularly in long-term-care settings), providing specialized programs for adaptive wheelchair fitting allows for a proactive approach to seating problems.

  6. A review of postural orthostatic tachycardia syndrome.

    LENUS (Irish Health Repository)

    Carew, Sheila

    2012-01-31

    A 21-year-old female reports an 18-month history of light-headedness on standing. This is often associated with palpitations and a feeling of intense anxiety. She has had two black-outs in the past 12 months. She is not taking any regular medications. Her supine blood pressure was 126\\/84 mmHg with a heart rate of 76 bpm, and her upright blood pressure was 122\\/80 mmHg with a heart rate of 114 bpm. A full system examination was otherwise normal. She had a 12-lead electrocardiogram performed which was unremarkable. She was referred for head-up tilt testing. She was symptomatic during the test and lost consciousness at 16 min. Figure 1 summarizes her blood pressure and heart rate response to tilting. A diagnosis of postural orthostatic tachycardia syndrome with overlapping vasovagal syncope was made.

  7. A Methodology for Investigating Adaptive Postural Control

    Science.gov (United States)

    McDonald, P. V.; Riccio, G. E.

    1999-01-01

    Our research on postural control and human-environment interactions provides an appropriate scientific foundation for understanding the skill of mass handling by astronauts in weightless conditions (e.g., extravehicular activity or EVA). We conducted an investigation of such skills in NASA's principal mass-handling simulator, the Precision Air-Bearing Floor, at the Johnson Space Center. We have studied skilled movement-body within a multidisciplinary context that draws on concepts and methods from biological and behavioral sciences (e.g., psychology, kinesiology and neurophysiology) as well as bioengineering. Our multidisciplinary research has led to the development of measures, for manual interactions between individuals and the substantial environment, that plausibly are observable by human sensory systems. We consider these methods to be the most important general contribution of our EVA investigation. We describe our perspective as control theoretic because it draws more on fundamental concepts about control systems in engineering than it does on working constructs from the subdisciplines of biomechanics and motor control in the bio-behavioral sciences. At the same time, we have attempted to identify the theoretical underpinnings of control-systems engineering that are most relevant to control by human beings. We believe that these underpinnings are implicit in the assumptions that cut across diverse methods in control-systems engineering, especially the various methods associated with "nonlinear control", "fuzzy control," and "adaptive control" in engineering. Our methods are based on these theoretical foundations rather than on the mathematical formalisms that are associated with particular methods in control-systems engineering. The most important aspects of the human-environment interaction in our investigation of mass handling are the functional consequences that body configuration and stability have for the pick up of information or the achievement of

  8. Myopia, posture and the visual environment.

    Science.gov (United States)

    Charman, W Neil

    2011-09-01

    Evidence for a possible role for the peripheral retina in the control of refractive development is discussed, together with Howland's suggestion (Paper presented at the 13th International Myopia Conference, Tubingen, Germany, July 26-29, 2010) that signals to generate appropriate growth might be derived from ocular oblique astigmatism. The dependence of this, or similar peripheral mechanisms, on exposure to a uniform field of near-zero dioptric vergence is emphasized: this is required to ensure a consistent relationship between the astigmatic image fields and the retina. This condition is satisfied by typical outdoor environments. In contrast, indoor environments are likely to be unfavourable to peripherally-based emmetropization, since dioptric stimuli may vary widely across the visual field. This is particularly the case when short working distances or markedly asymmetric head postures with respect to the visual task are adopted.

  9. Postural Instability in Children with ADHD Is Improved by Methylphenidate.

    Science.gov (United States)

    Bucci, Maria P; Stordeur, Coline; Acquaviva, Eric; Peyre, Hugo; Delorme, Richard

    2016-01-01

    HIGHLIGHTS Both spatial and temporal analyses of the Center of Pressure demonstrate that children with ADHD have poorer postural control than typically developing sex-, age-, and IQ-matched children.Poor sensory integration in postural control could partially explained the deficits in postural stability in children with ADHD.MPH treatment improves postural performance in both spatial and temporal domains in children with ADHD.MPH improves postural control specifically when visual and proprioceptive inputs are misleading.Such improvement could be due to MPH effects on neurons, facilitating cerebellar processing of postural control. The aim of this study was to examine postural control in children with ADHD and explore the effect of methylphenidate (MPH), using spatial and temporal analyses of the center of pressure (CoP). Thirty-eight children with ADHD (mean age 9.82 ± 0.37 years) and 38 sex- age- and IQ-matched children with typically development were examined. Postural stability was evaluated using the Multitest Equilibre machine (Framiral®) at inclusion and after 1 month of MPH in children with ADHD. Postural stability was assessed by recording under several conditions: with eyes open and fixed on a target, with eyes closed and with vision perturbed by optokinetic stimulation, on stable and unstable platforms. At inclusion, we observed poor spatial and temporal postural stability in children with ADHD. The spectral power index was higher in children with ADHD than in controls. Canceling time was shorter at low and medium frequencies of oscillation and longer at higher frequencies in children with ADHD. After 1 month of MPH, the surface area and mean velocity of the CoP decreased significantly under the most complex conditions (unstable platform in the absence of proprioceptive and visual inputs). The spectral power index decreased significantly after MPH while the canceling time did not change. Poor postural control in children with ADHD supports the

  10. Postural Instability in Children with ADHD Is Improved by Methylphenidate

    Science.gov (United States)

    Bucci, Maria P.; Stordeur, Coline; Acquaviva, Eric; Peyre, Hugo; Delorme, Richard

    2016-01-01

    HIGHLIGHTS Both spatial and temporal analyses of the Center of Pressure demonstrate that children with ADHD have poorer postural control than typically developing sex-, age-, and IQ-matched children.Poor sensory integration in postural control could partially explained the deficits in postural stability in children with ADHD.MPH treatment improves postural performance in both spatial and temporal domains in children with ADHD.MPH improves postural control specifically when visual and proprioceptive inputs are misleading.Such improvement could be due to MPH effects on neurons, facilitating cerebellar processing of postural control. The aim of this study was to examine postural control in children with ADHD and explore the effect of methylphenidate (MPH), using spatial and temporal analyses of the center of pressure (CoP). Thirty-eight children with ADHD (mean age 9.82 ± 0.37 years) and 38 sex- age- and IQ-matched children with typically development were examined. Postural stability was evaluated using the Multitest Equilibre machine (Framiral®) at inclusion and after 1 month of MPH in children with ADHD. Postural stability was assessed by recording under several conditions: with eyes open and fixed on a target, with eyes closed and with vision perturbed by optokinetic stimulation, on stable and unstable platforms. At inclusion, we observed poor spatial and temporal postural stability in children with ADHD. The spectral power index was higher in children with ADHD than in controls. Canceling time was shorter at low and medium frequencies of oscillation and longer at higher frequencies in children with ADHD. After 1 month of MPH, the surface area and mean velocity of the CoP decreased significantly under the most complex conditions (unstable platform in the absence of proprioceptive and visual inputs). The spectral power index decreased significantly after MPH while the canceling time did not change. Poor postural control in children with ADHD supports the

  11. Posture Estimation by Using High Frequency Markers and Kernel Regressions

    Science.gov (United States)

    Ono, Yuya; Iwai, Yoshio; Ishiguro, Hiroshi

    Recently, research fields of augmented reality and robot navigation are actively investigated. Estimating a relative posture between an object and a camera is an important task in these fields. In this paper, we propose a novel method for posture estimation by using high frequency markers and kernel regressions. The markers are embedded in an object's texture in the high frequency domain. We observe the change of spatial frequency of object's texture to estimate a current posture of the object. We conduct experiments to show the effectiveness of our method.

  12. Estimation of Human Body Shape and Posture Under Clothing

    OpenAIRE

    Wuhrer, Stefanie; Pishchulin, Leonid; Brunton, Alan; Shu, Chang; Lang, Jochen

    2013-01-01

    Estimating the body shape and posture of a dressed human subject in motion represented as a sequence of (possibly incomplete) 3D meshes is important for virtual change rooms and security. To solve this problem, statistical shape spaces encoding human body shape and posture variations are commonly used to constrain the search space for the shape estimate. In this work, we propose a novel method that uses a posture-invariant shape space to model body shape variation combined with a skeleton-bas...

  13. Delayed Random Walks: Modeling Human Posture Control

    Science.gov (United States)

    Ohira, Toru

    1998-03-01

    We consider a phenomenological description of a noisy trajectory which appears on a stabiliogram platform during human postural sway. We hypothesize that this trajectory arises due to a mixture of uncontrollable noise and a corrective delayed feedback to an upright position. Based on this hypothesis, we model the process with a biased random walk whose transition probability depends on its position at a fixed time delay in the past, which we call a delayed random walk. We first introduce a very simple model (T. Ohira and J. G. Milton, Phys.Rev.E. 52), 3277, (1995), which can nevertheless capture the rough qualitative features of the two--point mean square displacement of experimental data with reasonable estimation of delay time. Then, we discuss two approaches toward better capturing and understanding of the experimental data. The first approach is an extension of the model to include a spatial displacement threshold from the upright position below which no or only weak corrective feedback motion takes place. This can be incorporated into an extended delayed random walk model. Numerical simulations show that this extended model can better capture the three scaling region which appears in the two--point mean square displacement. The other approach studied the autocorrelation function of the experimental data, which shows oscillatory behavior. We recently investigated a delayed random walk model whose autocorrelation function has analytically tractable oscillatory behavior (T. Ohira, Phys.Rev.E. 55), R1255, (1997). We discuss how this analytical understanding and its application to delay estimation (T. Ohira and R. Sawatari, Phys.Rev.E. 55), R2077, (1997) could possibly be used to further understand the postural sway data.

  14. Postural correlates of viewing painful situations

    Directory of Open Access Journals (Sweden)

    Thierry eLelard

    2013-02-01

    Full Text Available Background: Emotional context may play a crucial role in movement production. According to simulation theories, emotional states affect motor systems. The aim of this study was to compare postural responses assessed by posturography and electromyography when subjects were instructed to imagine themselves in a painful or a non-painful situation.Methods: Twenty-nine subjects (22.3 ± 3.7 years participated in this study. While standing quietly on a posturographic platform, they were instructed to imagine themselves in a painful or non-painful situation. Displacement of the centre of pressure (COP, leg muscle electromyographic activity, heart rate, and electrodermal activity were assessed in response to painful and non-painful situations.Results:The anteroposterior path was shorter (p<0.05 when subjects imagined themselves in a painful situation (M = 148.0 ± 33.4 mm compared to a non-painful situation (158.2 ± 38.7 mm. Higher Tibialis Anterior (TA activity (RMS-TA = 3.38 ± 1.95 % vs 3.24 ± 1.85 %; p < 0.001 and higher variability of Soleus (SO activity (variation coefficient of RMS-SO = 13.5 ± 16.2 % vs M = 9.0% ± 7.2 %; p<0.05 were also observed in painful compared to non-painful situations. No significant changes were observed for other physiological data Conclusion: This study demonstrates that simulation of painful situations induces changes in postural control and leg muscle activation compared to non-painful situations, as increased stiffness was demonstrated in response to aversive pictures in accordance with previous results.

  15. Postural control of the human mandible.

    Science.gov (United States)

    Miles, Timothy S

    2007-04-01

    This article reviews recent experimental evidence explaining the mechanisms that support the mandible in its rest or postural position when the head is stationary and during locomotion. At rest, and during slow jaw movements, there is alternating activation of the jaw-opening and jaw-closing muscles which arises from a central pattern generator. However, this cannot account for the rest position of the mandible even when the head is stationary. Jaw movements and masticatory muscle activity were measured in subjects who stood, walked and ran on a treadmill. Even during walking, there are no bursts of masseter EMG time-locked to heel-landing. However, when subjects ran, the downward movement of the mandible in each step evokes a burst of EMG in the masseters. This is a stretch reflex in the jaw-closing muscles, which acts to limit the downward movement of the mandible relative to the maxilla during locomotion, and to restore the mandibular position towards its rest position. Thus, when the head is stationary, the low-level activity in the jaw-opening and jaw-closing muscles does not contribute to the rest position. Instead, the mandible is supported by passive viscoelastic forces in perioral soft tissues which limit vertical jaw movements even when the head moves gently up and down during walking. When the head moves more vigorously up and down, stretch reflexes in the jaw-closing muscles limit the movement of the mandible. That is, both passive forces and active reflex responses maintain jaw posture within narrow limits during brisk head movements.

  16. Reliability of novel postural sway task test

    Directory of Open Access Journals (Sweden)

    Milan Sedliak

    2013-07-01

    Full Text Available The purpose of this study was to examine the reliability of parameters obtained from a novel postural sway task test based on body movements controlled by visual feedback. Fifty-nine volunteers were divided into two groups. The first group consisted of young (n = 32, 16 females and 16 males, age: 25.2 ± 3.4 years and the second group of elderly individuals (n = 27, 17 females and 10 males, age: 75.7 ± 6.9 years. Participants stood in parallel on a computer based stabilographic platform with the feet approximately a shoulder width apart, the toes slightly pointing outwards, the hands placed on the hips. The computer screen was placed approximately 1.5 meter from the platform at a height of subjects’ eyes. An instantaneous visual feedback of participant’s centre of pressure (COP was given in a form of a blue cross visible on the screen. Participants were instructed to keep the blue cross driven by movements of their hips as close as possible to a predefined curve flowing on the screen. Out of the 6 parameters studied, only the average distance of COP from the curve line and the sum of the COP crossings through the curve line showed high reliability. Correlation between these two highly reliable parameters was -0.89. There was also a statistical difference (p<0.001 between young and elderly in both the average distance of COP from the curve line and the sum of the COP crossings through the curve. To conclude, the novel postural sway task provides a simple tool with relatively low time burden needed for testing. The suggested output parameters measured are highly reliable and easy to interpret.

  17. Shoulder posture and median nerve sliding

    Directory of Open Access Journals (Sweden)

    Dilley Andrew

    2004-07-01

    Full Text Available Abstract Background Patients with upper limb pain often have a slumped sitting position and poor shoulder posture. Pain could be due to poor posture causing mechanical changes (stretch; local pressure that in turn affect the function of major limb nerves (e.g. median nerve. This study examines (1 whether the individual components of slumped sitting (forward head position, trunk flexion and shoulder protraction cause median nerve stretch and (2 whether shoulder protraction restricts normal nerve movements. Methods Longitudinal nerve movement was measured using frame-by-frame cross-correlation analysis from high frequency ultrasound images during individual components of slumped sitting. The effects of protraction on nerve movement through the shoulder region were investigated by examining nerve movement in the arm in response to contralateral neck side flexion. Results Neither moving the head forward or trunk flexion caused significant movement of the median nerve. In contrast, 4.3 mm of movement, adding 0.7% strain, occurred in the forearm during shoulder protraction. A delay in movement at the start of protraction and straightening of the nerve trunk provided evidence of unloading with the shoulder flexed and elbow extended and the scapulothoracic joint in neutral. There was a 60% reduction in nerve movement in the arm during contralateral neck side flexion when the shoulder was protracted compared to scapulothoracic neutral. Conclusion Slumped sitting is unlikely to increase nerve strain sufficient to cause changes to nerve function. However, shoulder protraction may place the median nerve at risk of injury, since nerve movement is reduced through the shoulder region when the shoulder is protracted and other joints are moved. Both altered nerve dynamics in response to moving other joints and local changes to blood supply may adversely affect nerve function and increase the risk of developing upper quadrant pain.

  18. Magnetic Coordinate Systems

    CERN Document Server

    Laundal, K M

    2016-01-01

    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the...

  19. Supercritical Airfoil Coordinates

    Data.gov (United States)

    National Aeronautics and Space Administration — Rectangular Supercritical Wing (Ricketts) - design and measured locations are provided in an Excel file RSW_airfoil_coordinates_ricketts.xls . One sheet is with Non...

  20. Understanding social motor coordination.

    Science.gov (United States)

    Schmidt, R C; Fitzpatrick, Paula; Caron, Robert; Mergeche, Joanna

    2011-10-01

    Recently there has been much interest in social coordination of motor movements, or as it is referred to by some researchers, joint action. This paper reviews the cognitive perspective's common coding/mirror neuron theory of joint action, describes some of its limitations and then presents the behavioral dynamics perspective as an alternative way of understanding social motor coordination. In particular, behavioral dynamics' ability to explain the temporal coordination of interacting individuals is detailed. Two experiments are then described that demonstrate how dynamical processes of synchronization are apparent in the coordination underlying everyday joint actions such as martial art exercises, hand-clapping games, and conversations. The import of this evidence is that emergent dynamic patterns such as synchronization are the behavioral order that any neural substrate supporting joint action (e.g., mirror systems) would have to sustain.

  1. Environmental Compliance Issue Coordination

    Science.gov (United States)

    An order to establish the Department of Energy (DOE) requirements for coordination of significant environmental compliance issues to ensure timely development and consistent application of Departmental environmental policy and guidance

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

    OpenAIRE

    Toscano, Carla Fabiana da Silva; Silva, Polyanna Waleska Amorim da; Silva,Lícia Vasconcelos Carvalho da; Melo,Renato de Souza

    2011-01-01

    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 consi...

  3. Posture in dentists: Sitting vs. standing positions during dentistry work: An EMG study

    OpenAIRE

    Pejčić, Nataša; Đurić-Jovičić, Milica; Miljković, Nadica; id_orcid 0000-0002-3933-6076; Popović, Dejan B.; id_orcid 0000-0002-0882-7227; Petrović, Vanja

    2016-01-01

    Introduction Adequate working posture is important for overall health. Inappropriate posture may increase fatigue, decrease efficiency, and eventually lead to injuries. Objective The purpose was to examine posture positions used during dentistry work. Methods In order to quantify different posture positions, we recorded muscle activity and positions of body segments. The position (inclination) data of the back was used to assess two postures: sitting and standing during standard dental interv...

  4. [Coordination and donation].

    Science.gov (United States)

    Elizalde, J; Lorente, M

    2006-01-01

    The progressive incorporation of organ transplants as a therapeutic resource resulted in organisational adaptation and overall transplant management, leading to the emergence of the figure of the transplant coordinator in the mid-1980s. In Spain, the National Organisation of Transplants (Organización Nacional de Transplantes - ONT) was created, establishing a system - called the "Spanish model" - based on a network of coordinators at three levels: national, the autonomous community and the hospital. This organisational structure is a point of reference at the world level. The prevalence of the Intensive Medicine specialisation amongst hospital transplant coordinators is remarkable. The majority of organs proceed from brain-dead patients with beating hearts and this requires the infrastructure offered by intensive care units. The functions of the coordinator can be summarised in guaranteeing a synchrony of all the elements and teams that come together in an organisational chain that has come to be called the "process of donation". Schematically, the crucial points that the hospital coordinator develops are the following: - Detection of the potential donor. - Maintenance of the donor. - Diagnosis of brain death. - Family consent. - Preparation of the hospital logistics. - Helping the relatives. - Direct involvement in the Program of Guarantee of Quality. - Person of reference in any activity related to the transplant. It would be desirable to achieve the creation of transplant coordination teams, with univocal messages, professionalism and a permanent input of the so-called "human factor", which is so necessary and also so close to the transplant world.

  5. Continuous parallel coordinates.

    Science.gov (United States)

    Heinrich, Julian; Weiskopf, Daniel

    2009-01-01

    Typical scientific data is represented on a grid with appropriate interpolation or approximation schemes,defined on a continuous domain. The visualization of such data in parallel coordinates may reveal patterns latently contained in the data and thus can improve the understanding of multidimensional relations. In this paper, we adopt the concept of continuous scatterplots for the visualization of spatially continuous input data to derive a density model for parallel coordinates. Based on the point-line duality between scatterplots and parallel coordinates, we propose a mathematical model that maps density from a continuous scatterplot to parallel coordinates and present different algorithms for both numerical and analytical computation of the resulting density field. In addition, we show how the 2-D model can be used to successively construct continuous parallel coordinates with an arbitrary number of dimensions. Since continuous parallel coordinates interpolate data values within grid cells, a scalable and dense visualization is achieved, which will be demonstrated for typical multi-variate scientific data.

  6. Magnetic Coordinate Systems

    Science.gov (United States)

    Laundal, K. M.; Richmond, A. D.

    2017-03-01

    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.

  7. Effects of running with backpack loads during simulated gravitational transitions: Improvements in postural control

    Science.gov (United States)

    Brewer, Jeffrey David

    The National Aeronautics and Space Administration is planning for long-duration manned missions to the Moon and Mars. For feasible long-duration space travel, improvements in exercise countermeasures are necessary to maintain cardiovascular fitness, bone mass throughout the body and the ability to perform coordinated movements in a constant gravitational environment that is six orders of magnitude higher than the "near weightlessness" condition experienced during transit to and/or orbit of the Moon, Mars, and Earth. In such gravitational transitions feedback and feedforward postural control strategies must be recalibrated to ensure optimal locomotion performance. In order to investigate methods of improving postural control adaptation during these gravitational transitions, a treadmill based precision stepping task was developed to reveal changes in neuromuscular control of locomotion following both simulated partial gravity exposure and post-simulation exercise countermeasures designed to speed lower extremity impedance adjustment mechanisms. The exercise countermeasures included a short period of running with or without backpack loads immediately after partial gravity running. A novel suspension type partial gravity simulator incorporating spring balancers and a motor-driven treadmill was developed to facilitate body weight off loading and various gait patterns in both simulated partial and full gravitational environments. Studies have provided evidence that suggests: the environmental simulator constructed for this thesis effort does induce locomotor adaptations following partial gravity running; the precision stepping task may be a helpful test for illuminating these adaptations; and musculoskeletal loading in the form of running with or without backpack loads may improve the locomotor adaptation process.

  8. In Vivo Spinal Posture during Upright and Reclined Sitting in an Office Chair

    Directory of Open Access Journals (Sweden)

    Roland Zemp

    2013-01-01

    Full Text Available Increasing numbers of people spend the majority of their working lives seated in an office chair. Musculoskeletal disorders, in particular low back pain, resulting from prolonged static sitting are ubiquitous, but regularly changing sitting position throughout the day is thought to reduce back problems. Nearly all currently available office chairs offer the possibility to alter the backrest reclination angles, but the influence of changing seating positions on the spinal column remains unknown. In an attempt to better understand the potential to adjust or correct spine posture using adjustable seating, five healthy subjects were analysed in an upright and reclined sitting position conducted in an open, upright MRI scanner. The shape of the spine, as described using the vertebral bodies’ coordinates, wedge angles, and curvature angles, showed high inter-subject variability between the two seating positions. The mean lumbar, thoracic, and cervical curvature angles were 29±15°, -29±4°, and 13±8° for the upright and 33±12°, -31±7°, and 7±7° for the reclined sitting positions. Thus, a wide range of seating adaptation is possible through modification of chair posture, and dynamic seating options may therefore provide a key feature in reducing or even preventing back pain caused by prolonged static sitting.

  9. A validation of a posture matching approach for the determination of 3D cumulative back loads.

    Science.gov (United States)

    Sutherland, Chad A; Albert, Wayne J; Wrigley, Allan T; Callaghan, Jack P

    2008-03-01

    The purpose of this project was to investigate the amount of error in calculating cumulative lumbar spine kinetics using a posture matching approach (3DMatch) compared to a 3D coordinate electromagnetic tracking approach (FASTRAK). Six subjects were required to perform five repeats each of two symmetrical and two asymmetrical lifts while being simultaneously recorded from 4 camera views at viewing angles of 0 degrees , 45 degrees , 60 degrees and 90 degrees to the sagittal plane while wearing eight FASTRAK sensors to define an 8 segment rigid link model (RLM) of the head, arms, and trunk. Four hundred and eighty lifts (6 subjects x20 lifts x4 camera views) were analyzed using the 3DMatch posture-matching program to calculate the following cumulative loads at the L4/L5 joint: compression, anterior shear, posterior shear, reaction shear and extension moment. The errors in cumulative load calculation were determined as the difference between the values calculated for the same lifts using a 3D RLM that used electromagnetic motion tracking sensors (FASTRAK) positioned at the segment center of masses as model inputs. No significant difference (pposture matching by trained users can provide reasonable 3D data to calculate cumulative low back loads with a biomechanical model.

  10. Cineradiographic analysis of mouse postural response to alteration of gravity and jerk (gravity deceleration rate).

    Science.gov (United States)

    Hasegawa, Katsuya; de Campos, Priscila S; Zeredo, Jorge L; Kumei, Yasuhiro

    2014-04-24

    The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6) were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%-200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of -0.3~-0.4 j (g/s) induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.

  11. An Integrated Wireless Wearable Sensor System for Posture Recognition and Indoor Localization.

    Science.gov (United States)

    Huang, Jian; Yu, Xiaoqiang; Wang, Yuan; Xiao, Xiling

    2016-10-31

    In order to provide better monitoring for the elderly or patients, we developed an integrated wireless wearable sensor system that can realize posture recognition and indoor localization in real time. Five designed sensor nodes which are respectively fixed on lower limbs and a standard Kalman filter are used to acquire basic attitude data. After the attitude angles of five body segments (two thighs, two shanks and the waist) are obtained, the pitch angles of the left thigh and waist are used to realize posture recognition. Based on all these attitude angles of body segments, we can also calculate the coordinates of six lower limb joints (two hip joints, two knee joints and two ankle joints). Then, a novel relative localization algorithm based on step length is proposed to realize the indoor localization of the user. Several sparsely distributed active Radio Frequency Identification (RFID) tags are used to correct the accumulative error in the relative localization algorithm and a set-membership filter is applied to realize the data fusion. The experimental results verify the effectiveness of the proposed algorithms.

  12. An Integrated Wireless Wearable Sensor System for Posture Recognition and Indoor Localization

    Directory of Open Access Journals (Sweden)

    Jian Huang

    2016-10-01

    Full Text Available In order to provide better monitoring for the elderly or patients, we developed an integrated wireless wearable sensor system that can realize posture recognition and indoor localization in real time. Five designed sensor nodes which are respectively fixed on lower limbs and a standard Kalman filter are used to acquire basic attitude data. After the attitude angles of five body segments (two thighs, two shanks and the waist are obtained, the pitch angles of the left thigh and waist are used to realize posture recognition. Based on all these attitude angles of body segments, we can also calculate the coordinates of six lower limb joints (two hip joints, two knee joints and two ankle joints. Then, a novel relative localization algorithm based on step length is proposed to realize the indoor localization of the user. Several sparsely distributed active Radio Frequency Identification (RFID tags are used to correct the accumulative error in the relative localization algorithm and a set-membership filter is applied to realize the data fusion. The experimental results verify the effectiveness of the proposed algorithms.

  13. Models of the vestibular system and postural control

    Science.gov (United States)

    Young, L. R.; Weiss, A.

    1974-01-01

    Applications of control theory and systems analysis to the problem of orientation and posture control are discussed, with the possible long range goals of contributing to the development of hardware for rehabilitation of the handicapped.

  14. Transition from Rocking to Crawling: Postural Constraints on Infant Movement.

    Science.gov (United States)

    Goldfield, Eugene C.

    1989-01-01

    Investigated postural constraints on movement of 15 6-month-old infants. Results suggested that each of the developing capabilities of orienting, reaching, and kicking assumed a specific function for locomotion at the stage of crawling. (RJC)

  15. Observing working postures in industry: Examples of OWAS application.

    Science.gov (United States)

    Karhu, O; Härkönen, R; Sorvali, P; Vepsäläinen, P

    1981-03-01

    A practical method for identifying and evaluating poor working postures, ie the Ovako Working Posture Analysing System (OWAS), was presented in an earlier paper (Karhu et al, 1977). The application of the method is here described by means of two examples. One is a case study undertaken by members of an ergonomics training course, in which a marked improvement in working posture was achieved by OWAS analysis of critical activities. The second illustrates the effect of setting up a multidisciplinary group in order to develop an alternative method for the installation and maintenance of steel mill equipment. In both examples, application of the OWAS method led to improved posture in the situations studied, and to the likelihood of its wider industrial use.

  16. Correcting working postures in industry: A practical method for analysis.

    Science.gov (United States)

    Karhu, O; Kansi, P; Kuorinka, I

    1977-12-01

    A practical method for identifying and evaluating poor working postures, ie, the Ovako Working Posture Analysing System (OWAS), is presented. The method consists of two parts. The first is an observational technique for evaluating working postures. It can be used by work-study engineers in their daily routine and it gives reliable results after a short training period. The second part of the method is a set of criteria for the redesign of working methods and places. The criteria are based on evaluations made by experienced workers and ergonomics experts. They take into consideration factors such as health and safety, but the main emphasis is placed on the discomfort caused by the working postures. The method has been extensively used in the steel company which participated in its development. Complete production lines have already been redesigned on the basis of information gathered from OWAS, the result being more comfortable workplaces as well as a positive effect on production quality.

  17. Task, muscle and frequency dependent vestibular control of posture

    NARCIS (Netherlands)

    Forbes, P.A.; Siegmund, G.P.; Schouten, A.C.; Blouin, J.S.

    2015-01-01

    The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular

  18. Hand posture recognizer based on separator wavelet networks

    Science.gov (United States)

    Bouchrika, Tahani; Jemai, Olfa; Zaied, Mourad; Ben Amar, Chokri

    2015-12-01

    This paper presents a novel hand posture recognizer based on separator wavelet networks (SWNs). Aiming at creating a robust and rapid hand posture recognizer, we have contributed by proposing a new training algorithm for the wavelet network classifier based on fast wavelet transform (FWN). So, the contribution resides in reducing the number of WNs modeling training data. To make that, inspiring from the adaboost feature selection method, we thought to create SWNs (n-1 WNs for n classes) instead of modeling each training sample by its wavelet network (WN). By proposing the new training algorithm, the recognition phase will be positively influenced. It will be more rapid thanks to the reduction of the number of comparisons between test images WNs and training WNs. Comparisons with other works, employing universal hand posture datasets are presented and discussed. Obtained results have shown that the new hand posture recognizer is comparable to previously established ones.

  19. Assessment of striatal & postural deformities in patients with Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Sanjay Pandey

    2016-01-01

    Interpretation & conclusions: Our results showed that striatal and postural deformities were common and present in about half of the patients with PD. These deformities we more common in patients with advanced stage of PD.

  20. Upper extremity function: What's posture got to do with it?

    Science.gov (United States)

    Harbourne, Regina; Kamm, Kathi

    2015-01-01

    This perspective paper reviews the linkage between developing postural control and upper extremity function. We suggest updated principles for guiding clinical practice, based on current views from motor learning, motor development, and motor control research. Using three clinical examples, we illustrate principles focusing on the use of variability, the importance of errors in learning movement, task specific exploration and practice, and the critical timing necessary to build skill of the upper extremity in a variety of postures. These principles differ from historic approaches in therapeutic exercise, which treated posture as a separate system and a precursor for extremity skill building. We maintain that current movement science supports the tight interaction of posture and upper extremity function through developmental time and in real time, such that one system cannot be considered separate from the other. Specific suggestions for clinical practice flow from the guiding principles outlined in this paper.