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Sample records for anticipatory postural reactions

  1. Cortical involvement in anticipatory postural reactions in man

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  2. Kinesio Taping in Young Healthy Subjects Does Not Affect Postural Reflex Reactions and Anticipatory Postural Adjustments of the Trunk: A Pilot Study

    Science.gov (United States)

    Voglar, Matej; Sarabon, Nejc

    2014-01-01

    Therapeutic Kinesio Taping method is used for treatment of various musculo-skeletal conditions. Kinesio Taping might have some small clinically important beneficial effects on range of motion and strength but findings about the effects on proprioception and muscle activation are inconsistent. The aim of this study was to test if Kinesio Taping influences anticipatory postural adjustments and postural reflex reactions. To test the hypothesis twelve healthy young participants were recruited in randomized, participants blinded, placebo controlled cross-over study. In the experimental condition the tape was applied over the paravertebral muscles and in placebo condition sham application of the tape was done transversally over the lumbar region. Timing of anticipatory postural adjustments to fast voluntary arms movement and postural reflex reactions to sudden loading over the hands were measured by means of superficial electromyography before and one hour after each tape application. Results showed no significant differences between Kinesio Taping and placebo taping conditions for any of the analyzed muscles in anticipatory postural adaptations (F1,11 0.64, η2 0.07, η2 Kinesio Taping does not affect postural reflex reactions in young healthy population. Earlier anticipatory postural adjustments were observed under both Kinesio Taping and placebo conditions. There were no significant differences between Kinesio Taping and placebo condition. PMID:25177198

  3. Kinesio taping in young healthy subjects does not affect postural reflex reactions and anticipatory postural adjustments of the trunk: a pilot study.

    Science.gov (United States)

    Voglar, Matej; Sarabon, Nejc

    2014-09-01

    Therapeutic Kinesio Taping method is used for treatment of various musculo-skeletal conditions. Kinesio Taping might have some small clinically important beneficial effects on range of motion and strength but findings about the effects on proprioception and muscle activation are inconsistent. The aim of this study was to test if Kinesio Taping influences anticipatory postural adjustments and postural reflex reactions. To test the hypothesis twelve healthy young participants were recruited in randomized, participants blinded, placebo controlled cross-over study. In the experimental condition the tape was applied over the paravertebral muscles and in placebo condition sham application of the tape was done transversally over the lumbar region. Timing of anticipatory postural adjustments to fast voluntary arms movement and postural reflex reactions to sudden loading over the hands were measured by means of superficial electromyography before and one hour after each tape application. Results showed no significant differences between Kinesio Taping and placebo taping conditions for any of the analyzed muscles in anticipatory postural adaptations (F1,11 0.64, η2 0.07, η(2) Kinesio Taping does not affect postural reflex reactions in young healthy population.Earlier anticipatory postural adjustments were observed under both Kinesio Taping and placebo conditions.There were no significant differences between Kinesio Taping and placebo condition.

  4. Kinesio Taping in Young Healthy Subjects Does Not Affect Postural Reflex Reactions and Anticipatory Postural Adjustments of the Trunk: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Matej Voglar, Nejc Sarabon

    2014-09-01

    Full Text Available Therapeutic Kinesio Taping method is used for treatment of various musculo-skeletal conditions. Kinesio Taping might have some small clinically important beneficial effects on range of motion and strength but findings about the effects on proprioception and muscle activation are inconsistent. The aim of this study was to test if Kinesio Taping influences anticipatory postural adjustments and postural reflex reactions. To test the hypothesis twelve healthy young participants were recruited in randomized, participants blinded, placebo controlled cross-over study. In the experimental condition the tape was applied over the paravertebral muscles and in placebo condition sham application of the tape was done transversally over the lumbar region. Timing of anticipatory postural adjustments to fast voluntary arms movement and postural reflex reactions to sudden loading over the hands were measured by means of superficial electromyography before and one hour after each tape application. Results showed no significant differences between Kinesio Taping and placebo taping conditions for any of the analyzed muscles in anticipatory postural adaptations (F1,11 0.64, η2 0.07, η2 < 0.49. Anticipatory postural adjustments of erector spinae and multifidus muscles were initiated significantly earlier after application of taping (regardless of technique compared to pre-taping (F1,11 = 5.02, p = 0.046, η2 = 0.31 and F1,11 = 6.18, p = 0.030, η2 = 0.36 for erector spinae and multifidus, respectively. Taping application over lumbar region has potential beneficial effects on timing of anticipatory postural adjustments regardless of application technique but no effect on postural reflex reactions in young pain free participants. Further research in patients with low back pain would be encouraged.

  5. Kinesio Taping in Young Healthy Subjects Does Not Affect Postural Reflex Reactions and Anticipatory Postural Adjustments of the Trunk: A Pilot Study

    OpenAIRE

    Voglar, Matej; Sarabon, Nejc

    2014-01-01

    Therapeutic Kinesio Taping method is used for treatment of various musculo-skeletal conditions. Kinesio Taping might have some small clinically important beneficial effects on range of motion and strength but findings about the effects on proprioception and muscle activation are inconsistent. The aim of this study was to test if Kinesio Taping influences anticipatory postural adjustments and postural reflex reactions. To test the hypothesis twelve healthy young participants were recruited in ...

  6. 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...

  7. Contribution of seat and foot reaction forces to anticipatory postural adjustments (APAs) in sitting isometric ramp pushes.

    Science.gov (United States)

    Le Bozec, Serge; Bouisset, Simon

    2009-10-01

    The aim of this paper was to examine the role of the upper and lower body on the dynamic phenomena, which precede the voluntary movement (anticipatory postural adjustments: APAs), and the way in which they contribute to postural control. In this view, sitting subjects were asked to perform horizontal two-handed ramp pushes as quickly as possible. A dynamometric bar was used to provide the push force (F(x)). Local reaction forces along the antero-posterior and vertical axes, at the seat and foot-rests (R(Sx), R(Sz), and R(fx), R(fz), respectively), as well as global ones (R(x) and R(z)), were measured. Two postural conditions were considered: full (100 BP) and one-third ischio-femoral contact (30 BP). Anticipatory postural adjustments durations (dAPAs) were measured between the onset of global or local (that is, at the seat and foot level) reaction forces, and the onset of push force increase. Firstly, the dAPAs were longer at the foot than at the seat level, that is, the APA sequence starts at the foot level: it is suggested that a "posturo-focal" sequence is followed, whose progression order is precisely dependent on the postural conditions. Moreover, the APA peak amplitudes (pAPA), measured at the seat contact were significantly greater than the corresponding ones measured at the foot contact: the upper body dynamics are larger than the lower body dynamics. Secondly, a greater peak push force (pF(x)) entailed significant dAPA increases, in preference to pAPA increases. As APAs are dynamic phenomena, they can perturb balance, suggesting that, in order to avoid unnecessary perturbation, APAs are increased in terms of duration rather than amplitude. Lastly, the impulses corresponding to the push force increase ("BPI(x)") and to the APA periods ("ACPI(x)") were calculated. As ACPI(x) was very low as compared to BPI(x), it was suggested that the APA action was limited to the period of the voluntary movement onset.

  8. 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

  9. 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.

  10. Anticipatory postural adjustments in conditions of simulated reduced gravity.

    Science.gov (United States)

    Li, Xiaoyan; Aruin, Alexander S

    2008-11-01

    The study investigates the role of decreased gravity on anticipatory postural adjustments (APAs). Subjects performed fast bilateral arm-raising movements and load releases while in conditions of normal and reduced gravity. Reduced gravity conditions were simulated by changing the ratio between the body weight and mass. Electromyographic (EMG) activity of dorsal and ventral trunk and leg muscles, as well as ground reaction forces, were recorded and quantified within the time intervals typical of APAs. Anticipatory postural adjustments were seen in normal gravity conditions as well as in simulated reduced gravity conditions. However, in decreased gravity conditions, the magnitudes of the anticipatory integrals of electromyography muscle activity (EMG) were smaller compared to normal gravity. Moreover, there was a linear relation between EMG and simulated decreased gravity and between the displacement of the center of pressure (COP) and simulated gravity. The study provides new data on the effect of gravity in feed-forward postural control and stresses the importance of taking into consideration its role in the control of upright posture.

  11. Anticipatory Postural Control of Stability during Gait Initiation Over Obstacles of Different Height and Distance Made Under Reaction-Time and Self-Initiated Instructions

    Science.gov (United States)

    Yiou, Eric; Artico, Romain; Teyssedre, Claudine A.; Labaune, Ombeline; Fourcade, Paul

    2016-01-01

    Despite the abundant literature on obstacle crossing in humans, the question of how the central nervous system (CNS) controls postural stability during gait initiation with the goal to clear an obstacle remains unclear. Stabilizing features of gait initiation include anticipatory postural adjustments (APAs) and lateral swing foot placement. To answer the above question, 14 participants initiated gait as fast as possible in three conditions of obstacle height, three conditions of obstacle distance and one obstacle-free (control) condition. Each of these conditions was performed with two levels of temporal pressure: reaction-time (high-pressure) and self-initiated (low-pressure) movements. A mechanical model of the body falling laterally under the influence of gravity and submitted to an elastic restoring force is proposed to assess the effect of initial (foot-off) center-of-mass position and velocity (or “initial center-of-mass set”) on the stability at foot-contact. Results showed that the anticipatory peak of mediolateral (ML) center-of-pressure shift, the initial ML center-of-mass velocity and the duration of the swing phase, of gait initiation increased with obstacle height, but not with obstacle distance. These results suggest that ML APAs are scaled with swing duration in order to maintain an equivalent stability across experimental conditions. This statement is strengthened by the results obtained with the mechanical model, which showed how stability would be degraded if there was no adaptation of the initial center-of-mass set to swing duration. The anteroposterior (AP) component of APAs varied also according to obstacle height and distance, but in an opposite way to the ML component. Indeed, results showed that the anticipatory peak of backward center-of-pressure shift and the initial forward center-of-mass set decreased with obstacle height, probably in order to limit the risk to trip over the obstacle, while the forward center-of-mass velocity at foot

  12. A method to model anticipatory postural control in driver braking events.

    Science.gov (United States)

    Östh, Jonas; Eliasson, Erik; Happee, Riender; Brolin, Karin

    2014-09-01

    Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated braking differ greatly from autonomous braking. In the present study, an anticipatory postural response was hypothesized, modelled in a whole-body HBM with feedback controlled muscles, and validated using existing volunteer data. The anticipatory response was modelled as a time dependent change in the reference value for the feedback controllers, which generates correcting moments to counteract the braking deceleration. The results showed that, in 11 m/s(2) driver braking simulations, including the anticipatory postural response reduced the peak forward displacement of the head by 100mm, of the shoulder by 30 mm, while the peak head flexion rotation was reduced by 18°. The HBM kinematic response was within a one standard deviation corridor of corresponding test data from volunteers performing maximum braking. It was concluded that the hypothesized anticipatory responses can be modelled by changing the reference positions of the individual joint feedback controllers that regulate muscle activation levels. The addition of anticipatory postural control muscle activations appears to explain the difference in occupant kinematics between driver and autonomous braking. This method of modelling postural reactions can be applied to the simulation of other driver voluntary actions, such as emergency avoidance by steering.

  13. Improvement of anticipatory postural adjustments for balance control: effect of a single training session.

    Science.gov (United States)

    Kanekar, Neeta; Aruin, Alexander S

    2015-04-01

    Humans use anticipatory and compensatory postural strategies to maintain and restore balance when perturbed. Inefficient generation and utilization of anticipatory postural adjustments (APAs) is one of the reasons for postural instability. The aim of the study was to investigate the role of training in improvement of APAs and its effect on subsequent control of posture. Thirteen healthy young adults were exposed to predictable external perturbations before and after a single training session consisting of catches of a medicine ball thrown at the shoulder level. 3-D body kinematics, EMG activity of thirteen trunk and lower limb muscles, and ground reaction forces were recorded before and immediately after a single training session. Muscle onsets, EMG integrals, center of pressure (COP), and center of mass (COM) displacements were analyzed during the anticipatory and compensatory phases of postural control. The effect of a single training session was seen as significantly early muscle onsets and larger anticipatory COP displacements. As a result, significantly smaller peak COM displacements were observed after the perturbation indicating greater postural stability. The outcome of this study provides a background for examining the role of training in improvement of APAs and its effect on postural stability in individuals in need.

  14. The effect of aging on anticipatory postural control.

    Science.gov (United States)

    Kanekar, Neeta; Aruin, Alexander S

    2014-04-01

    The aim of the study was to investigate the differences in anticipatory postural adjustments (APAs) between young and older adults and its effect on subsequent control of posture. Ten healthy older adults and thirteen healthy young adults were exposed to predictable external perturbations using the pendulum impact paradigm. Electromyographic activity of the trunk and leg muscles, the center of pressure (COP), and center of mass (COM) displacements in the anterior-posterior direction were recorded and analyzed during the anticipatory and compensatory postural adjustments (CPAs) phases of postural control. The effect of aging was seen as delayed anticipatory muscle activity and larger compensatory muscle responses in older adults as compared to young adults. Moreover, in spite of such larger reactive responses, older adults were still more unstable, exhibiting larger COP and COM peak displacements after the perturbation than young adults when exposed to similar postural disturbances. Nonetheless, while APAs are impaired in older adults, the ability to recruit muscles anticipatorily is largely preserved; however, due to their smaller magnitudes and delayed onsets, it is likely that their effectiveness in reducing the magnitude of CPAs is smaller. The outcome of the study lends support toward investigating the ways of improving anticipatory postural control in people with balance impairments due to aging or neurological disorders.

  15. Cortical control of anticipatory postural adjustments prior to stepping.

    Science.gov (United States)

    Varghese, J P; Merino, D M; Beyer, K B; McIlroy, W E

    2016-01-28

    Human bipedal balance control is achieved either reactively or predictively by a distributed network of neural areas within the central nervous system with a potential role for cerebral cortex. While the role of the cortex in reactive balance has been widely explored, only few studies have addressed the cortical activations related to predictive balance control. The present study investigated the cortical activations related to the preparation and execution of anticipatory postural adjustment (APA) that precede a step. This study also examined whether the preparatory cortical activations related to a specific movement is dependent on the context of control (postural component vs. focal component). Ground reaction forces and electroencephalographic (EEG) data were recorded from 14 healthy adults while they performed lateral weight shift and lateral stepping with and without initially preloading their weight to the stance leg. EEG analysis revealed that there were distinct movement-related potentials (MRPs) with concurrent event-related desynchronization (ERD) of mu and beta rhythms prior to the onset of APA and also to the onset of foot-off during lateral stepping in the fronto-central cortical areas. Also, the MRPs and ERD prior to the onset of APA and onset of lateral weight shift were not significantly different suggesting the comparable cortical activations for the generation of postural and focal movements. The present study reveals the occurrence of cortical activation prior to the execution of an APA that precedes a step. Importantly, this cortical activity appears independent of the context of the movement.

  16. Anticipatory postural adjustments in individuals with multiple sclerosis.

    Science.gov (United States)

    Krishnan, Vennila; Kanekar, Neeta; Aruin, Alexander S

    2012-01-11

    Individuals with multiple sclerosis (MS) frequently exhibit difficulties in balance maintenance. It is known that anticipatory postural adjustments (APAs) play an important role in postural control. However, no information exists on how people living with MS utilize APAs for control of posture. A group of individuals with MS and a group of healthy control subjects performed rapid arm flexion and extension movements while standing on a force platform. Electromyographic (EMG) activity of six trunk and leg muscles and displacement of center of pressure (COP) were recorded and quantified within the time intervals typical of APAs. Individuals with MS demonstrated diminished ability to produce directional specific patterns of anticipatory EMGs as compared to control subjects. In addition, individuals with MS demonstrated smaller magnitudes of anticipatory muscle activation. This was associated with larger displacements of the COP during the balance restoration phase. These results suggest the importance of anticipatory postural control in maintenance of vertical posture in individuals with MS. The outcome of the study could be used while developing rehabilitation strategies focused on balance restoration in individuals with MS.

  17. The effect of aging on anticipatory postural control

    OpenAIRE

    Kanekar, Neeta; Aruin, Alexander S.

    2014-01-01

    The aim of the study was to investigate the differences in anticipatory (APAs) postural adjustments between young and older adults and its effect on subsequent control of posture. Ten healthy older adults and thirteen healthy young adults were exposed to predictable external perturbations using the pendulum-impact paradigm. EMG activity of the trunk and leg muscles, the center of pressure (COP), and center of mass (COM) displacements in the anterior-posterior (AP) direction were recorded and ...

  18. Enhancing Anticipatory Postural Adjustments: A Novel Approach to Balance Rehabilitation

    OpenAIRE

    2016-01-01

    Balance impairment is common in individuals with neurological disorders and older adults and is a major cause of falls in these populations. Evidence on the effectiveness of conventional interventions for balance restoration is limited. We describe a novel approach to balance rehabilitation that is based on enhancing anticipatory postural adjustments.

  19. Aging and balance control in response to external perturbations: role of anticipatory and compensatory postural mechanisms.

    Science.gov (United States)

    Kanekar, Neeta; Aruin, Alexander S

    2014-06-01

    The ability to maintain balance deteriorates with increasing age. Anticipatory and compensatory postural adjustments (APAs and CPAs, respectively), both, are known to be affected in the elderly. We examined the effect of aging on the ability of older adults to utilize APAs and its effect on subsequent control of posture (CPAs). Ten elderly individuals were exposed to external predictable and unpredictable perturbations applied to the upper body in the sagittal plane. Body kinematics, electromyographic activity of 13 muscles, and ground reaction forces were analyzed during the anticipatory and compensatory phases of postural control. The elderly were capable of recognizing an upcoming predictable perturbation and activated muscles prior to it. However, the older adults used different muscle strategies and sequence of muscle recruitment than that reported in young adults. Additionally, when the perturbations were unpredictable, no APAs were seen which resulted in large CPAs and greater peak displacements of the center of pressure (COP) and center of mass (COM) following perturbations. As opposed to this, when the perturbations were predictable, APAs were seen in older adults resulting in significantly smaller CPAs. The presence and utilization of APAs in older adults also improved postural stability following the perturbation as seen by significantly smaller COP and COM peak displacements. Using APAs in older adults significantly reduces the need for large CPAs, resulting in greater postural stability following a perturbation. The results provide a foundation for investigating the role of training in improving the interplay between anticipatory and compensatory postural control in older adults.

  20. Anticipatory postural adjustments in children with hemiplegia and diplegia.

    Science.gov (United States)

    Girolami, Gay L; Shiratori, Takako; Aruin, Alexander S

    2011-12-01

    Anticipatory postural adjustments (APAs) play an important role in the performance of many activities requiring the maintenance of standing posture. However, little is known about if and how children with cerebral palsy (CP) generate APAs. Two groups of children with CP (hemiplegia and diplegia) and a group of children with typical motor development performed arm flexion and extension movements while standing on a force platform. Electromyographic activity of six trunk and leg muscles and displacement of center of pressure (COP) were recorded. Children with CP were able to generate anticipatory postural adjustments and produce directionally specific APAs and COP displacements similar to those described in adults and typically developing children. However, children with diplegia were unable to generate APAs of the same magnitude as children with typical development and hemiplegia and had higher baseline muscle activity prior to movement. In children with diplegia, COP was posteriorly displaced and peak acceleration was smaller during bilateral extension compared to children with hemiplegia. The outcomes of the study highlight the role of APAs in the control of posture of children with CP and point out the similarities and differences in anticipatory control in children with diplegia and hemiplegia. These differences may foster ideas for treatment strategies to enhance APAs in children with CP.

  1. 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.

  2. Atypical anticipatory postural adjustments during gait initiation among individuals with sub-acute stroke.

    Science.gov (United States)

    Rajachandrakumar, Roshanth; Fraser, Julia E; Schinkel-Ivy, Alison; Inness, Elizabeth L; Biasin, Lou; Brunton, Karen; McIlroy, William E; Mansfield, Avril

    2017-02-01

    Anticipatory postural adjustments, executed prior to gait initiation, help preserve lateral stability when stepping. Atypical patterns of anticipatory activity prior to gait initiation may occur in individuals with unilateral impairment (e.g., stroke). This study aimed to determine the prevalence, correlates, and consequences of atypical anticipatory postural adjustment patterns prior to gait initiation in a sub-acute stroke population. Forty independently-ambulatory individuals with sub-acute stroke stood on two force plates and initiated gait at a self-selected speed. Medio-lateral centre of pressure displacement was calculated and used to define anticipatory postural adjustments (shift in medio-lateral centre of pressure >10mm from baseline). Stroke severity, motor recovery, and functional balance and mobility status were also obtained. Three patterns were identified: single (typical), absent (atypical), and multiple (atypical) anticipatory postural adjustments. Thirty-five percent of trials had atypical anticipatory postural adjustments (absent and multiple). Frequency of absent anticipatory postural adjustments was negatively correlated with walking speed. Multiple anticipatory postural adjustments were more prevalent when leading with the non-paretic than the paretic limb. Trials with multiple anticipatory postural adjustments had longer duration of anticipatory postural adjustment and time to foot-off, and shorter unloading time than trials with single anticipatory postural adjustments. A high prevalence of atypical anticipatory control prior to gait initiation was found in individuals with stroke. Temporal differences were identified with multiple anticipatory postural adjustments, indicating altered gait initiation. These findings provide insight into postural control during gait initiation in individuals with sub-acute stroke, and may inform interventions to improve ambulation in this population.

  3. Effects of lateral perturbations and changing stance conditions on anticipatory postural adjustment.

    Science.gov (United States)

    Santos, Marcio J; Aruin, Alexander S

    2009-06-01

    The study investigates the role of lateral muscles and changing stance conditions in anticipatory postural adjustments (APAs). Subjects stood laterally to an aluminum pendulum released by an experimenter and were required to stop it with their right or left hand. Stance conditions were manipulated by having the subjects stand in the following positions: on a single limb (SS), with feet together (narrow base of support, NB), and with feet shoulder width apart (regular base of support, RB). Bilateral EMG activity of dorsal, ventral, and lateral trunk and leg muscles and ground reaction forces were recorded and quantified within the time intervals typical of APAs. Anticipatory postural adjustments were seen in all experimental conditions, and their magnitudes depended on the stance and the side of perturbation. Accordingly, APAs in lateral muscles increased on the side of perturbation in SS condition, while simultaneous activation of dorsal muscles occurred on the contralateral side. Smaller APAs were seen in lateral muscles in conditions with a wider base of support (NB, RB) and APAs in dorsal muscles were smaller in NB - in comparison to RB - stance. The results of the present study provide new data on the role of lateral, ventral, and dorsal muscles in anticipatory postural control when dealing with lateral perturbations in conditions of postural instability.

  4. The effect of Parkinson's disease and levodopa on adaptation of anticipatory postural adjustments.

    Science.gov (United States)

    Hall, L M; Brauer, S G; Horak, F; Hodges, P W

    2013-10-10

    Postural support alters anticipatory postural adjustments (APAs). Efficient adaptation to changes in postural support in reactive and centrally initiated postural synergies is impaired in Parkinson's disease (PD). This study examined whether APAs are affected differently by familiar and novel supports in people with PD, ON and OFF levodopa. The effect of PD and levodopa on the ability to immediately adapt APAs to changes in support and refine with practice was also investigated. Fourteen people with PD and 14 healthy control participants performed 20 single rapid leg lift tasks in four support conditions: unsupported, bilateral handgrip (familiar), bite plate (novel) and a combined handgrip+bite plate condition. APAs, identified from force plate data, were characterized by an increase in the vertical ground reaction force under the lifted leg as a result of a shift of weight toward the stance limb. Results showed the ability to incorporate familiar and novel external supports into the postural strategy was preserved in PD. Controls and PD patients in the OFF state further refined the postural strategy with practice as evidenced by changes in amplitude of vertical ground reaction forces and forces applied to support apparatus within conditions between the initial and final trials. In the ON state, people with PD failed to refine the use of postural supports in any condition. The results suggest that immediate postural adaptation is intact in people with PD and unaffected by levodopa administration but the ability to refine postural adaptations with task experience is compromised by dopamine therapy.

  5. Improvement of anticipatory postural adjustments for balance control: effect of a single training session

    OpenAIRE

    Kanekar, Neeta; Aruin, Alexander S.

    2014-01-01

    Humans use anticipatory and compensatory postural strategies to maintain and restore balance when perturbed. Inefficient generation and utilization of anticipatory postural adjustments (APAs) is one of the reasons for postural instability. The aim of the study was to investigate the role of training in improvement of APAs and its effect on subsequent control of posture. Thirteen healthy young adults were exposed to predictable external perturbations before and after a single training session ...

  6. Representation of grasp postures and anticipatory motor planning in children.

    Science.gov (United States)

    Stöckel, Tino; Hughes, Charmayne M L; Schack, Thomas

    2012-11-01

    In this study, we investigated anticipatory motor planning and the development of cognitive representation of grasp postures in children aged 7, 8, and 9 years. Overall, 9-year-old children were more likely to plan their movements to end in comfortable postures, and have distinct representational structures of certain grasp postures, compared to the 7- and 8-year old children. Additionally, the sensitivity toward comfortable end-states (end-state comfort) was related to the mental representation of certain grasp postures. Children with grasp comfort related and functionally well-structured representations were more likely to have satisfied end-state comfort in both the simple and the advanced planning condition. In contrast, end-state comfort satisfaction for the advanced planning condition was much lower for children whose cognitive representations were not structured by grasp comfort. The results of the present study support the notion that cognitive action representation plays an important role in the planning and control of grasp postures.

  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. The threat of a support surface translation affects anticipatory postural control.

    Science.gov (United States)

    Phanthanourak, Angel L; Cleworth, Taylor W; Adkin, Allan L; Carpenter, Mark G; Tokuno, Craig D

    2016-10-01

    This study examined how postural threat in the form of a potential perturbation affects an individual's ability to perform a heel raise. Seventeen adults completed three conditions: i) low threat, where participants performed a heel raise in response to a "go" tone, ii) high threat, where participants either heard the same "go" tone, for which they performed a heel raise, or experienced a support surface translation in the medio-lateral direction that disturbed their balance, and iii) choice reaction time task, where participants either completed a heel raise in response to the same "go" tone or a toe raise in response to a lower pitched tone. For all heel raise trials, anticipatory postural adjustments (APAs) were quantified from center of pressure (COP) recordings and electromyographic (EMG) activity from the tibialis anterior (TA) and soleus (SOL). Results indicated that participants exhibited larger APAs, as reflected by the greater backward COP displacement (p=0.038) and velocity (p=0.022) as well as a larger TA EMG amplitude (p=0.045), during the high threat condition. During the execution phase of the heel raise, an earlier (p=0.014) and larger (p=0.041) SOL EMG activation were observed during the high threat condition. These results contrast with previous findings of reduced APAs when the postural threat was evoked through changes in surface height. Therefore, the characteristics of the postural threat must be considered to isolate the effects of threat on anticipatory movement control.

  9. 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…

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Influence of temporal pressure on anticipatory postural control of medio-lateral stability during rapid leg flexion.

    Science.gov (United States)

    Yiou, E; Hussein, T; Larue, J

    2012-03-01

    During leg flexion from erect posture, postural stability along the medio-lateral direction is organized in advance during "anticipatory postural adjustments" (APAs). This study aimed to investigate the influence of temporal pressure on this anticipatory postural control of medio-lateral stability. Eight young healthy participants performed series of leg flexions (1) as soon as possible in response to an acoustic signal (reaction-time condition; condition with temporal pressure) and (2) in a self-initiated condition (no temporal pressure). Results showed that APAs duration was shorter in the reaction-time condition as compared to the self-initiated condition; this shortening was compensated by an increase in the medio-lateral center-of-pressure displacement so that the dynamic stability reached at foot-off, as measured by the "extrapolated center-of-mass", remained unchanged. It is concluded that when a complex task is performed under temporal pressure, the central nervous system is able to modulate the spatio-temporal features of APAs in a way to both hasten the initiation of the voluntary movement and maintain optimal conditions of dynamic stability. In other words, it seems that the central nervous system does not "trade off optimal stability for speed of movement initiation under reaction-time condition", as it had been proposed in the literature.

  15. Enhancement of anticipatory postural adjustments in older adults as a result of a single session of ball throwing exercise.

    Science.gov (United States)

    Aruin, Alexander S; Kanekar, Neeta; Lee, Yun-Ju; Ganesan, Mohan

    2015-02-01

    The aim of the study was to investigate the role of short-term training in improvement of anticipatory postural adjustments (APAs) and its effect on subsequent control of posture in older adults. Nine healthy older adults were exposed to self-initiated and predictable external perturbations before and after a single training session consisting of throwing a medicine ball. EMG activity of eight trunk and leg muscles and ground reaction forces were recorded before and immediately after the training session. Muscle onsets and center of pressure displacements were analyzed during the anticipatory and compensatory phases of postural control. The training involving throwing of a medicine ball resulted in enhancement of the generation of APAs seen as significantly early onsets of leg and trunk muscle activity prior to the bilateral arm flexion task. Significantly early activation of postural muscles observed prior to the predictable external perturbation, the task that was not a part of training, indicates the transfer of the effect of the single training session. The observed training-related improvements of APAs suggest that APA-focused rehabilitation could be effective in improving postural control, functional balance, mobility, and quality of life in the elderly.

  16. Effects of anticipatory anxiety and visual input on postural sway in an aversive situation.

    Science.gov (United States)

    Ishida, Mitsuo; Saitoh, Junko; Wada, Maki; Nagai, Masanori

    2010-04-19

    We have previously reported that state anxiety scores were positively correlated with postural sway while standing upright and gazing at a visual target (Ohno et al., 2004 [16]). The present study examines the effect of anticipatory anxiety and visual input on postural control in healthy individuals. An unpredictable aversive sound (100dB SPL) was delivered in order to induce anticipatory anxiety. Participants were asked to stand upright on a force plate with their eyes open and closed, and their center of pressure (COP) was measured. Analysis of the postural parameters revealed that the path lengths of the COP and the enveloped areas were greater in the anticipatory situation with the aversive sound than in the silent situation. Fast Fourier transform analysis showed that the frequency component related to vestibular inputs (0.1-1.0Hz) was increased during the anticipatory situation. The lower frequency (anticipatory anxiety in healthy participants amplified the sway regardless of whether the eyes were open or closed, and that the vestibular inputs greatly influenced the amplification of postural sway.

  17. Anticipatory postural adjustments associated with a loading perturbation in children with hemiplegic and diplegic cerebral palsy.

    Science.gov (United States)

    Shiratori, T; Girolami, G L; Aruin, A S

    2016-10-01

    Anticipatory postural adjustments (APAs) in preparation for predictable externally induced loading perturbation were studied in children with typically development (TD), hemiplegic (HEMI), and diplegic (DIPL) cerebral palsy. Twenty-seven children (n = 9 in each group) were asked to stand and catch a load dropped from a pre-specified height. Electrical activity of the leg and trunk muscles and center of pressure (COP) displacements were recorded to quantify the APAs. All groups were able to generate APAs prior to the perturbation, but the magnitude was smaller and the onset was delayed in the dorsal (agonist) postural muscles in both HEMI and DIPL as compared to TD. HEMI and DIPL also generated APAs in the antagonist postural muscles. Anticipatory backward COP displacement was significantly different from the baseline value only in the TD and HEMI. HEMI and DIPL displayed a different postural control strategy; HEMI showed no difference in background postural activity from TD, but with diminished APAs in the agonist postural muscles compared to TD, while DIPL showed a higher background postural activity and diminished APAs in the agonist postural muscles compared to TD. These differences are important to consider when designing rehabilitation programs to improve posture and movement control in children with hemiplegic and diplegic cerebral palsy.

  18. Effects of neck flexion on contingent negative variation and anticipatory postural control during arm movement while standing.

    Science.gov (United States)

    Fujiwara, Katsuo; Tomita, Hidehito; Maeda, Kaoru; Kunita, Kenji

    2009-02-01

    We investigated the effects of neck flexion on contingent negative variation (CNV) and anticipatory postural control using an arm flexion task in standing. CNV was adopted to evaluate the state of activation of brain areas related to anticipatory postural control. Subjects were required to flex the arms in response to a sound stimulus preceded by a warning sound stimulus. Two different intervals (2.0 and 3.5s) between these two stimuli were used in neck position in quiet standing (neck resting) and neck position at 80% angle of maximal neck flexion. The mean amplitude of CNV 100-ms before the response stimulus, recorded from a Cz electrode, was calculated. Onset timing of activation of the postural muscles (lumbar paraspinal, biceps femoris and gastrocnemius) with respect to the anterior deltoid was analyzed. Reaction time at the anterior deltoid was significantly shorter in the 2.0s period than in the 3.5s period, and in the neck flexion than in the neck resting in both periods. In the 2.0s, but not in the 3.5s period, neck flexion resulted in an increased CNV amplitude and an increased duration of preceding activation of the postural muscles, and the correlation between these increases was significant.

  19. Knee trembling during freezing of gait represents multiple anticipatory postural adjustments.

    Science.gov (United States)

    Jacobs, Jesse V; Nutt, John G; Carlson-Kuhta, Patricia; Stephens, Marilee; Horak, Fay B

    2009-02-01

    Freezing of gait (FoG) is an episodic, brief inability to step that delays gait initiation or interrupts ongoing gait. FoG is often associated with an alternating shaking of the knees, clinically referred to as knee trembling or trembling in place. The pathophysiology of FoG and of the concomitant trembling knees is unknown; impaired postural adjustment in preparation for stepping is one hypothesis. We examined anticipatory postural adjustments (APAs) prior to protective steps induced by a forward loss of balance in 10 Parkinson's disease (PD) subjects with marked FoG and in 10 control subjects. The amplitude and timing of the APAs were determined from changes in the vertical ground-reaction forces recorded by a force plate under each foot and were confirmed by electromyographic recordings of bilateral medial gastrocnemius, tibialis anterior and tensor fascia latae muscles. Protective steps were accomplished with a single APA followed by a step for control subjects, whereas PD subjects frequently exhibited multiple, alternating APAs coexistent with the knee trembling commonly observed during FoG as well as delayed, inadequate or no stepping. These multiple APAs were not delayed in onset and were of similar or larger amplitude than the single APAs exhibited by the control subjects. These observations suggest that multiple APAs produce the knee trembling commonly associated with FoG and that FoG associated with a forward loss of balance is caused by an inability to couple a normal APA to the stepping motor pattern.

  20. Anticipatory Posturing of the Vocal Tract Reveals Dissociation of Speech Movement Plans from Linguistic Units.

    Directory of Open Access Journals (Sweden)

    Sam Tilsen

    Full Text Available Models of speech production typically assume that control over the timing of speech movements is governed by the selection of higher-level linguistic units, such as segments or syllables. This study used real-time magnetic resonance imaging of the vocal tract to investigate the anticipatory movements speakers make prior to producing a vocal response. Two factors were varied: preparation (whether or not speakers had foreknowledge of the target response and pre-response constraint (whether or not speakers were required to maintain a specific vocal tract posture prior to the response. In prepared responses, many speakers were observed to produce pre-response anticipatory movements with a variety of articulators, showing that that speech movements can be readily dissociated from higher-level linguistic units. Substantial variation was observed across speakers with regard to the articulators used for anticipatory posturing and the contexts in which anticipatory movements occurred. The findings of this study have important consequences for models of speech production and for our understanding of the normal range of variation in anticipatory speech behaviors.

  1. Anticipatory Posturing of the Vocal Tract Reveals Dissociation of Speech Movement Plans from Linguistic Units.

    Science.gov (United States)

    Tilsen, Sam; Spincemaille, Pascal; Xu, Bo; Doerschuk, Peter; Luh, Wen-Ming; Feldman, Elana; Wang, Yi

    2016-01-01

    Models of speech production typically assume that control over the timing of speech movements is governed by the selection of higher-level linguistic units, such as segments or syllables. This study used real-time magnetic resonance imaging of the vocal tract to investigate the anticipatory movements speakers make prior to producing a vocal response. Two factors were varied: preparation (whether or not speakers had foreknowledge of the target response) and pre-response constraint (whether or not speakers were required to maintain a specific vocal tract posture prior to the response). In prepared responses, many speakers were observed to produce pre-response anticipatory movements with a variety of articulators, showing that that speech movements can be readily dissociated from higher-level linguistic units. Substantial variation was observed across speakers with regard to the articulators used for anticipatory posturing and the contexts in which anticipatory movements occurred. The findings of this study have important consequences for models of speech production and for our understanding of the normal range of variation in anticipatory speech behaviors.

  2. Threat-induced changes in attention during tests of static and anticipatory postural control.

    Science.gov (United States)

    Zaback, Martin; Carpenter, Mark G; Adkin, Allan L

    2016-03-01

    Postural threat, manipulated through changes in surface height, influences postural control. Evidence suggests changes in attention may contribute to this relationship. However, limited research has explored where and how attention is reallocated when threatened. The primary aim of this study was to describe changes in attention when presented with a postural threat, while a secondary aim was to explore associations between changes in attention and postural control. Eighty-two healthy young adults completed tests of static (quiet standing) and anticipatory (rise to toes) postural control under threatening and non-threatening conditions. Participants completed an open-ended questionnaire after each postural task which asked them to list what they thought about or directed their attention toward. Each item listed was assigned a percentage value reflecting how much attention it occupied. Exit interviews were completed to help confirm where attention was directed. Five attention categories were identified: movement processes, threat-relevant stimuli, self-regulatory strategies, task objectives, and task-irrelevant information. For both postural tasks, the percentage values and number of items listed for movement processes, threat-relevant stimuli, and self-regulatory strategies increased under threatening compared to non-threatening conditions, while the percentage values and number of items listed for task objectives and task-irrelevant information decreased. Changes in attention related to movement processes and self-regulatory strategies were associated with changes in static postural control, while changes in attention related to threat-relevant stimuli were associated with changes in anticipatory postural control. These results suggest that threat-induced changes in attention are multidimensional and contribute to changes in postural control.

  3. Modulation of anticipatory postural activity for multiple conditions of a whole-body pointing task.

    Science.gov (United States)

    Tolambiya, A; Chiovetto, E; Pozzo, T; Thomas, E

    2012-05-17

    This is a study on associated postural activities during the anticipatory segments of a multijoint movement. Several previous studies have shown that they are task dependant. The previous studies, however, have mostly been limited in demonstrating the presence of modulation for one task condition, that is, one aspect such as the distance of the target or the direction of reaching. Real-life activities like whole-body pointing, however, can vary in several ways. How specific is the adaptation of the postural activities for the diverse possibilities of a whole-body pointing task? We used a classification paradigm to answer this question. We examined the anticipatory postural electromyograms for four different types of whole-body pointing tasks. The presence of task-dependent modulations in these signals was probed by performing four-way classification tests using a support vector machine (SVM). The SVM was able to achieve significantly higher than chance performance in correctly predicting the movements at hand (Chance performance 25%). Using only anticipatory postural muscle activity, the correct movement at hand was predicted with a mean rate of 62%. Because this is 37% above chance performance, it suggests the presence of postural modulation for diverse conditions. The anticipatory activities consisted of both activations and deactivations. Movement prediction with the use of the activating muscles was significantly better than that obtained with the deactivating muscles. This suggests that more specific modulations for the movement at hand take place through activation, whereas the deactivation is more general. The study introduces a new method for investigating adaptations in motor control. It also sheds new light on the quantity and quality of information available in the feedforward segments of a voluntary multijoint motor activity.

  4. Independent Walking as a Major Skill for the Development of Anticipatory Postural Control: Evidence from Adjustments to Predictable Perturbations

    OpenAIRE

    Fabien Cignetti; Milan Zedka; Marianne Vaugoyeau; Christine Assaiante

    2013-01-01

    Although there is suggestive evidence that a link exists between independent walking and the ability to establish anticipatory strategy to stabilize posture, the extent to which this skill facilitates the development of anticipatory postural control remains largely unknown. Here, we examined the role of independent walking on the infants' ability to anticipate predictable external perturbations. Non-walking infants, walking infants and adults were sitting on a platform that produced continuou...

  5. The Effects of Kinesio Taping on Potential in Chronic Low Back Pain Patients Anticipatory Postural Control and Cerebral Cortex

    OpenAIRE

    Bae, Sea Hyun; Lee, Jeong Hun; Oh, Kyeong Ae; Kim, Kyung Yoon

    2013-01-01

    [Purpose] This study aimed to examine the effects of kinesio tape applied to chronic low back pain (CLBP) patients on anticipatory postural control and cerebral cortex potential. [Subjects and Methods] Twenty patients whose low back pain had continued for more than 12 weeks were selected and assigned to a control group (n=10) to which ordinary physical therapy was applied and an experimental group (n=10) to which kinesio tape was applied. Anticipatory postural control was evaluated using elec...

  6. Anticipatory and compensatory postural adjustments in conditions of body asymmetry induced by holding an object

    OpenAIRE

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

    2015-01-01

    The effect of body asymmetry on anticipatory and compensatory postural adjustments was studied. Ten healthy subjects stood on the force platform and held an object in one hand which induced body asymmetry. Subjects were exposed to external perturbations applied to their shoulders while standing with either normal or narrow base of support. Bilateral electromyographic activity (EMG) of dorsal and ventral trunk and leg muscles and center of pressure displacements were recorded. Data was analyze...

  7. The Role of Proprioception in the Sagittal Setting of Anticipatory Postural Adjustments During Gait Initiation

    Directory of Open Access Journals (Sweden)

    Pereira Marcelo P.

    2015-12-01

    Full Text Available Purpose. Previous studies have studied the role of proprioception on the setting of anticipatory postural adjustments (APA during gait initiation. However, these studies did not investigate the role of proprioception in the sagittal APA setting. We aimed to investigate the role of proprioception manipulation to induce APA sagittal adaptations on gait initiation. Methods. Fourteen healthy adults performed gait initiation without, and with, vibration applied before movement onset, and during movement. In addition, the effects of two different vibration frequencies (80 and 120Hz were tested. Vibration was applied bilaterally on the tibialis anterior, rectus femoris and trapezius superior. The first step characteristics, ground reaction forces and CoP behaviour were assessed. Results. Vibration improved gait initiation performance regardless of the moment it was applied. CoP velocity during the initial phase of APA was increased by vibration only when it was applied before movement. When vibration was applied to disturb the movement, no effects on the CoP behaviour were observed. Manipulation of vibration frequency had no effects. Conclusions. Rather than proprioception manipulation, the results suggest that post-vibratory effects and attentional mechanisms were responsible for our results. Taken together, the results show that sagittal APA setting is robust to proprioception manipulation.

  8. Modulation of anticipatory postural adjustments of gait using a portable powered ankle-foot orthosis.

    Science.gov (United States)

    Petrucci, Matthew N; MacKinnon, Colum D; Hsiao-Wecksler, Elizabeth T

    2013-06-01

    Prior to taking a step, properly coordinated anticipatory postural adjustments (APAs) are generated to control posture and balance as the body is propelled forward. External cues (audio, visual, somatosensory) have been shown to facilitate gait initiation by improving the magnitude and timing of APAs in Parkinson's disease (PD), but the efficacy of these cueing strategies has been limited by their inability to produce the forces required to generate an appropriate APA. To date, mechanical cueing paradigms have been relatively underexplored. Using healthy young adults, we investigated the use of a portable powered ankle-foot orthosis (PPAFO) to provide a modest torque at the ankle as a mechanical cue to initiate gait. Subjects were instructed to initiate gait in five test conditions: (1) self-initiated in running shoes [baseline-shoe], (2) self-initiated trial in unpowered passive PPAFO [baseline-passive], (3) with acoustic go-cue in passive PPAFO [acoustic-passive], (4) acoustic go-cue and simultaneous mechanical assist from powered PPAFO [acoustic-assist], and (5) mechanical assist cue only [assist]. APA characteristics were quantified using ground reaction force (GRF), center of pressure (COP), and electromyography (EMG) data. Mechanical cueing significantly increased medial-lateral COP and GRF peak amplitude, and decreased GRF time to peak amplitude, COP and GRF onset times, and time to toe off. Mechanical cueing conditions also demonstrated consistent bimodal EMG behaviors across all subjects. Overall, these data suggest that the mechanical assist from the PPAFO can significantly improve APA timing parameters and increase APA force production in healthy young adults.

  9. Anticipatory and compensatory postural adjustments in conditions of body asymmetry induced by holding an object.

    Science.gov (United States)

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

    2015-11-01

    The effect of body asymmetry on anticipatory and compensatory postural adjustments was studied. Ten healthy subjects stood on the force platform and held an object in one hand which induced body asymmetry. Subjects were exposed to external perturbations applied to their shoulders while standing with either normal or narrow base of support. Bilateral electromyographic activity (EMG) of dorsal and ventral trunk and leg muscles and center-of-pressure displacements were recorded. Data was analyzed within the intervals typical for anticipatory (APA) and compensatory postural adjustments. Integrals of EMG activity and co-contraction and reciprocal activation of muscles were calculated and analyzed. Reciprocal activation of muscles on the target side and co-contraction of muscles on the contralateral side were seen when standing in asymmetrical stance and being subjected to external perturbations. Decreased magnitudes of co-contraction and reciprocal activation of muscles were seen in the APA phase while standing asymmetrically with narrow base of support. The findings highlight the importance of investigating the role of body asymmetry in maintaining control of vertical posture. The outcome of the study provides a foundation for future studies focusing on improvement in postural control in individuals with body asymmetry due to unilateral weakness.

  10. Effects of preparatory period on anticipatory postural control and contingent negative variation associated with rapid arm movement in standing posture.

    Science.gov (United States)

    Maeda, Kaoru; Fujiwara, Katsuo

    2007-01-01

    We investigated CNS motor preparation state and anticipatory postural muscle activation while subjects performed bilateral rapid arm movement at various intervals between warning and response stimulus (preparatory period) during standing. Motor preparation state was evaluated by integrated values of the late components of the contingent negative variation (late CNV), obtained by averaging electroencephalograms during the last 100ms of the preparatory period. For quantifying anticipatory postural muscle activation, we measured the onset of burst activity in postural muscles (lumbar paraspinal, biceps femoris, and gastrocnemius) with respect to anterior deltoid activity and integrated values of preceding activation. Subjects performed the arm movement with minimal delay in the warning stimulus-response stimulus-motor response paradigm under preparatory periods of 2.0, 3.0 and 3.5s. Late CNV did not differ between the 2.0-s and 3.0-s period, but was significantly smaller in the 3.5-s period than in the 2.0-s period, suggesting difficulty in predicting response timing in the 3.5-s period. No change was found on integrated values of preceding activations of postural muscles. Burst onset of all postural muscles significantly preceded anterior deltoid activation in all periods. Burst activity for gastrocnemius only occurred earlier in the 3.5-s period than in the 2.0-s and 3.0-s periods. Weak correlations were observed between late CNV and onset time of gastrocnemius activity. It is suggested that earlier activation of gastrocnemius is a strategy adopted when response stimulus timing is relatively difficult to predict.

  11. Pain reported during prolonged standing is associated with reduced anticipatory postural adjustments of the deep abdominals.

    Science.gov (United States)

    Marshall, Paul W M; Romero, Rick; Brooks, Cristy

    2014-11-01

    Within the context of low back pain, the measurement of deep abdominal anticipatory postural adjustments (APAs) during rapid limb movement has received much interest. There is dispute about the association between APAs and back pain. Moreover, there is limited evidence examining compensatory postural adjustments (CPAs) in back pain. This study examined the relationship between APAs and CPAs with pain reported in the low back during 2 h of prolonged standing. Twenty-six participants with no history of severe back pain performed 2-h prolonged standing. APAs and CPAs of the deep abdominal muscles (transverse abdominis/internal obliques) were measured by surface electromyography during rapid shoulder flexion and extension. APAs and CPAs measured pre-standing revealed symmetrical anticipatory activity, but an asymmetry between the different sides of the abdominal wall for CPAs. APAs and CPAs measured pre-standing were not associated with pain reported during standing. For the whole group, APA amplitudes were reduced post-standing during shoulder flexion (p = 0.005). Pain reported during standing was associated with the changes in APA amplitudes post-standing (rs = 0.43, p = 0.002). These findings support previous research using hypertonic saline injections to induce back pain that showed reduced APA amplitudes, and extends findings to suggest pain does not effect compensatory postural adjustments.

  12. Shift of the Muscular Inhibition Latency during On-Line Acquisition of Anticipatory Postural Adjustments.

    Directory of Open Access Journals (Sweden)

    Fanny Barlaam

    Full Text Available During action, Anticipatory Postural Adjustments (APAs cancel the consequences of a movement on postural stabilization. Their muscular expression is characterized by early changes in the activity of the postural muscles, before the movement begins. To explore the mechanisms enabling the acquisition of APAs, a learning paradigm was designed in which the voluntary lifting of a load with one hand triggered the unloading of another load suspended below the contralateral forearm. The aim of this study was to investigate changes in the muscular expression that uncovers the progressive learning of new APAs. A trial-by-trial analysis of kinematic and electromyographic signals recorded on the right arm was conducted in twelve adults through six sessions of learning. Kinematic results reported an enhancement of the postural stabilization across learning. The main EMG pattern found during learning consisted of a flexor inhibition, where latency was shifted towards an earlier occurrence in parallel with the improvement of the postural performance. A linear regression analysis conducted between the inhibition latency and the maximal amplitude of elbow rotation showed that the earlier the inhibition onset, the better the postural stabilization. This study revealed that the progressive shift of the postural flexor inhibition latency could be considered as a reliable neurophysiological marker of the progressive learning of new APAs. Importantly, this marker could be used to track motor learning abnormalities in pathology. We relate our findings to the update of a forward predictive model of action, defined as a system that predicts beforehand the consequences of the action on posture.

  13. Anticipatory and compensatory postural adjustments in sitting in children with cerebral palsy.

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    Bigongiari, Aline; de Andrade e Souza, Flávia; Franciulli, Patrícia Martins; Neto, Semaan El Razi; Araujo, Rubens Correa; Mochizuki, Luis

    2011-06-01

    The aim of this study was to examine postural control in children with cerebral palsy performing a bilateral shoulder flexion to grasp a ball from a sitting posture. The participants were 12 typically developing children (control) without cerebral palsy and 12 children with cerebral palsy (CP). We analyzed the effect of ball mass (1 kg and 0.18 kg), postural adjustment (anticipatory, APA, and compensatory, CPA), and groups (control and CP) on the electrical activity of shoulder and trunk muscles with surface electromyography (EMG). Greater mean iEMG was seen in CPA, with heavy ball, and for posterior trunk muscles (pchildren with CP presented the highest EMG and level of co-activation (pcontrol group, whereas that relationship was negative for participants with CP. We suggest that the main postural control strategy in children is based on corrections after the beginning of the movement. The linear relationship between EMG and aging suggests that postural control development is affected by central nervous disease which may lead to an increase in muscle co-activation.

  14. Reactive and anticipatory control of posture and bipedal locomotion in a nonhuman primate.

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    Mori, Futoshi; Nakajima, Katsumi; Tachibana, Atsumichi; Takasu, Chijiko; Mori, Masahiro; Tsujimoto, Toru; Tsukada, Hideo; Mori, Shigemi

    2004-01-01

    Bipedal locomotion is a common daily activity. Despite its apparent simplicity, it is a complex set of movements that requires the integrated neural control of multiple body segments. We have recently shown that the juvenile Japanese monkey, M. fuscata, can be operant-trained to walk bipedally on moving treadmill. It can control the body axis and lower limb movements when confronted by a change in treadmill speed. M. fuscata can also walk bipedally on a slanted treadmill. Furthermore, it can learn to clear an obstacle attached to the treadmill's belt. When failing to clear the obstacle, the monkey stumbles but quickly corrects its posture and the associated movements of multiple motor segments to again resume smooth bipedal walking. These results give indication that in learning to walk bipedally, M. fuscata transforms relevant visual, vestibular, proprioceptive, and exteroceptive sensory inputs into commands that engage both anticipatory and reactive motor mechanisms. Both mechanisms are essential for meeting external demands imposed upon posture and locomotion.

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

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    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.

  16. Deficits in task-specific modulation of anticipatory postural adjustments in individuals with spastic diplegic cerebral palsy.

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    Tomita, Hidehito; Fukaya, Yoshiki; Ueda, Tomomi; Honma, Shota; Yamashita, Eriya; Yamamoto, Yoshiji; Mori, Etsuko; Shionoya, Katsuyoshi

    2011-05-01

    We examined whether individuals with spastic diplegic cerebral palsy (SDCP) have the ability to utilize lower leg muscles in anticipatory postural adjustments (APAs) associated with voluntary arm movement while standing, as well as the ability to modulate APAs with changes in the degree of postural perturbation caused by arm movement. Seven individuals with spastic diplegia (SDCP group, 12-22 yr of age) and seven age- and sex-matched individuals without disability (control group) participated in this study. Participants flexed both shoulders and lifted a load under two different load conditions, during which electromyographic activities of focal and postural muscles were recorded. Although the timing of anticipatory activation of the erector spinae and medial hamstring (MH) muscles was similar in the two participant groups, that of the gastrocnemius (GcM) muscle was significantly later in the SDCP group than in the control group. An increase in anticipatory postural muscle activity with an increase in load was observed in MH and GcM in the control group but not in GcM in the SDCP group. The degree of modulation in MH was significantly smaller in the SDCP group than in the control group. An additional experiment confirmed that these differences in APAs between the two participant groups were unlikely to be attributable to their differences in initial standing posture before load lift. The present findings suggest that lower leg muscles play a minor role in APAs in individuals with spastic diplegia. In addition, it is likely that these individuals have difficulty modulating anticipatory postural muscle activity with changes in the degree of postural perturbation.

  17. The supplementary motor area contributes to the timing of the anticipatory postural adjustment during step initiation in participants with and without Parkinson’s disease

    OpenAIRE

    Jacobs, Jesse V.; Lou, Jau-Shin; Kraakevik, Jeff A.; Fay B. Horak

    2009-01-01

    The supplementary motor area is thought to contribute to the generation of anticipatory postural adjustments (which act to stabilize supporting body segments prior to movement), but its precise role remains unclear. In addition, participants with Parkinson’s disease (PD) exhibit impaired function of the supplementary motor area as well as decreased amplitudes and altered timing of the anticipatory postural adjustment during step initiation, but the contribution of the supplementary motor area...

  18. Influence of fear of falling on anticipatory postural control of medio-lateral stability during rapid leg flexion.

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    Yiou, E; Deroche, T; Do, M C; Woodman, T

    2011-04-01

    During leg flexion from erect posture, postural stability is organized in advance during "anticipatory postural adjustments" (APA). During these APA, inertial forces are generated that propel the centre of gravity (CoG) laterally towards stance leg side. This study examined how fear of falling (FoF) may influence this anticipatory postural control of medio-lateral (ML) stability. Ten young healthy participants performed a series of leg flexions at maximal velocity from low and high surface heights (6 and 66 cm above ground, respectively). In this latter condition with increased FoF, stance foot was placed at the lateral edge of the support surface to induce maximal postural threat. Results showed that the amplitude of ML inertial forces generated during APA decreased with FoF; this decrease was compensated by an increase in APA duration so that the CoG position at time of swing foot-off was located further towards stance leg side. With these changes in ML APA, the CoG was propelled in the same final (unipodal) position above stance foot as in condition with low FoF. These results contrast with those obtained in the literature during quiet standing which showed that FoF did not have any influence on the ML component of postural control. It is proposed that ML APA are modified with increased FoF, in such a way that the risk of a sideway fall induced by the large CoG motion is attenuated.

  19. Anticipatory postural adjustments during lateral step motion in patients with hip osteoarthritis.

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    Tateuchi, Hiroshige; Ichihashi, Noriaki; Shinya, Masahiro; Oda, Shingo

    2011-02-01

    Patients with hip osteoarthritis (OA) have difficulty with mediolateral postural control. Since the symptom of hip OA includes joint pain, which mostly occurs upon initial movement, patients with hip OA might have disabling problems with movement initiation. This study aimed to identify the movement strategy during the anticipatory postural adjustments in the lateral step motion in patients with hip OA. We studied 18 female subjects with unilateral hip OA and 10 healthy subjects, and measured temporal, kinetic, and kinematic variables. Patients with hip OA required a longer duration of anticipation phase than the control subjects, the total duration of lateral stepping was not different between the groups. Displacement of the center of mass to the supporting (affected) side during the anticipation phase was not different between the two groups. These findings suggest that, in patients with hip OA, the center of mass slowly moved to the affected side. Furthermore, patients with hip OA showed greater shift of the trunk to the supporting side than did the control subjects. These movement characteristics might contribute to the achievement of both protection of the affected hip joint and quickness in the subsequent lateral step in patients with hip OA.

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

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    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.

  1. Temporal disruption of upper-limb anticipatory postural adjustments in cerebellar ataxic patients.

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    Bruttini, Carlo; Esposti, Roberto; Bolzoni, Francesco; Vanotti, Alessandra; Mariotti, Caterina; Cavallari, Paolo

    2015-01-01

    Voluntary movements induce postural perturbations, which are counteracted by anticipatory postural adjustments (APAs) that preserve body equilibrium. Little is known about the neural structures generating APAs, but several studies suggested a role of sensory-motor areas, basal ganglia, supplementary motor area and thalamus. However, the role of the cerebellum still remains an open question. The aim of this present paper is to shed further light on the role of cerebellum in APAs organization. Thus, APAs that stabilize the arm when the index finger is briskly flexed were recorded in 13 ataxic subjects (seven sporadic cases, four dominant ataxia type III and two autosomal recessive), presenting a slowly progressive cerebellar syndrome with four-limb dysmetria, and compared with those obtained in 13 healthy subjects. The pattern of postural activity was similar in the two groups [excitation in triceps and inhibition in biceps and anterior deltoid (AD)], but apparent modifications in timing were observed in all ataxic subjects in which, on average, triceps brachii excitation lagged the onset of the prime mover flexor digitorum superficialis by about 27 ms and biceps and AD inhibition were almost synchronous to it. Instead, in normal subjects, triceps onset was synchronous to the prime mover and biceps and AD anticipated it by about 40 ms. The observed disruption of the intra-limb APA organization confirms that the cerebellum is involved in APA control and, considering cerebellar subjects as a model of dysmetria, also supports the view that a proper APA chain may play a crucial role in refining movement metria.

  2. The Effects of Kinesio Taping on Potential in Chronic Low Back Pain Patients Anticipatory Postural Control and Cerebral Cortex

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    Bae, Sea Hyun; Lee, Jeong Hun; Oh, Kyeong Ae; Kim, Kyung Yoon

    2013-01-01

    [Purpose] This study aimed to examine the effects of kinesio tape applied to chronic low back pain (CLBP) patients on anticipatory postural control and cerebral cortex potential. [Subjects and Methods] Twenty patients whose low back pain had continued for more than 12 weeks were selected and assigned to a control group (n=10) to which ordinary physical therapy was applied and an experimental group (n=10) to which kinesio tape was applied. Anticipatory postural control was evaluated using electromyography, and movement-related cortical potential (MRCP) was assessed using electroencephalography. Clinical evaluation was performed using a visual analogue scale and the Oswestry disability index. [Results] According to the analysis results for anticipatory postural control, there were significant decreases in the transversus abdominis (TrA) muscle and the external oblique muscle in both groups. Among them, the TrA of the experimental group exhibited the greatest differences. According to the results of a between-group comparison, there was significant difference in the TrA between the two groups. There was also a significant decrease in the MRCP of both groups. In particular, changes in the movement monitoring potential (MMP) of the experimental group were greatest at Fz, C3, Cz, and C4. According to the between-group comparison, there were significant differences in MMP at F3, C3, and Cz. Both groups saw VAS and ODI significantly decrease. Among them, the ODI of the experimental group underwent the greatest change. [Conclusion] Kinesio tape applied to CLBP patients reduced their pain and positively affected their anticipatory postural control and MRCP. PMID:24396190

  3. The effects of kinesio taping on potential in chronic low back pain patients anticipatory postural control and cerebral cortex.

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    Bae, Sea Hyun; Lee, Jeong Hun; Oh, Kyeong Ae; Kim, Kyung Yoon

    2013-11-01

    [Purpose] This study aimed to examine the effects of kinesio tape applied to chronic low back pain (CLBP) patients on anticipatory postural control and cerebral cortex potential. [Subjects and Methods] Twenty patients whose low back pain had continued for more than 12 weeks were selected and assigned to a control group (n=10) to which ordinary physical therapy was applied and an experimental group (n=10) to which kinesio tape was applied. Anticipatory postural control was evaluated using electromyography, and movement-related cortical potential (MRCP) was assessed using electroencephalography. Clinical evaluation was performed using a visual analogue scale and the Oswestry disability index. [Results] According to the analysis results for anticipatory postural control, there were significant decreases in the transversus abdominis (TrA) muscle and the external oblique muscle in both groups. Among them, the TrA of the experimental group exhibited the greatest differences. According to the results of a between-group comparison, there was significant difference in the TrA between the two groups. There was also a significant decrease in the MRCP of both groups. In particular, changes in the movement monitoring potential (MMP) of the experimental group were greatest at Fz, C3, Cz, and C4. According to the between-group comparison, there were significant differences in MMP at F3, C3, and Cz. Both groups saw VAS and ODI significantly decrease. Among them, the ODI of the experimental group underwent the greatest change. [Conclusion] Kinesio tape applied to CLBP patients reduced their pain and positively affected their anticipatory postural control and MRCP.

  4. Detection of anticipatory postural adjustments prior to gait initiation using inertial wearable sensors

    Directory of Open Access Journals (Sweden)

    Sekine Masaki

    2011-04-01

    Full Text Available Abstract Background The present study was performed to evaluate and characterize the potential of accelerometers and angular velocity sensors to detect and assess anticipatory postural adjustments (APAs generated by the first step at the beginning of the gait. This paper proposes an algorithm to automatically detect certain parameters of APAs using only inertial sensors. Methods Ten young healthy subjects participated in this study. The subjects wore an inertial unit containing a triaxial accelerometer and a triaxial angular velocity sensor attached to the lower back and one footswitch on the dominant leg to detect the beginning of the step. The subjects were standing upright on a stabilometer to detect the center of pressure displacement (CoP generated by the anticipatory adjustments. The subjects were asked to take a step forward at their own speed and stride length. The duration and amplitude of the APAs detected by the accelerometer and angular velocity sensors were measured and compared with the results obtained from the stabilometer. The different phases of gait initiation were identified and compared using inertial sensors. Results The APAs were detected by all of the sensors. Angular velocity sensors proved to be adequate to detect the beginning of the step in a manner similar to the footswitch by using a simple algorithm, which is easy to implement in low computational power devices. The amplitude and duration of APAs detected using only inertial sensors were similar to those detected by the stabilometer. An automatic algorithm to detect APA duration using triaxial inertial sensors was proposed. Conclusions These results suggest that the feasibility of accelerometers is improved through the use of angular velocity sensors, which can be used to automatically detect and evaluate APAs. The results presented can be used to develop portable sensors that may potentially be useful for monitoring patients in the home environment, thus

  5. [The influence of the leg load and the support mobility under leg on the anticipatory postural adjustment].

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    Kazennikov, O V; Kireeva, T B; Shlykov, V Iu

    2015-01-01

    Anticipatory postural adjustment is an essential part of equilibrium maintainance during standing in human. So changes in stance condition could affect both control of equilibrium and anticipatory adjustment. Anticipatory changes in the stabilogram of each leg were studied in standing subject during the early stage of quick right arm lifting while legs were on two separated supports. The center of pressure (CP) movement was analyzed in three variants of experiment: both legs on immovable support, with only right leg on the movable support and with only left leg on the moveable support. In each standing condition subject stood with symmetrical load on two legs or with the load voluntary transferred to one leg. The anticipatory CP shift depended on the mobility of the support under the leg and on loading of the leg. While standing on unmovable supports with symmetrical load on the legs before lifting of the right arm CP of right leg shifted backward and CP of left leg--forward. While standing with one leg on movable support the anticipatory CP shift of this leg was small and did not depend on the load on the leg. However the shift of CP of the leg that was placed on the unmovable support depended on the load in the same way as in the case when both legs were on unmovable supports. Results suggested that since on movable support the support and proprioceptive afferent flow from distal part of the leg that was did not supply unambiguous information about body position, the role of distal joints in posture control is reduced.

  6. Does movement planning follow Fitts' law? Scaling anticipatory postural adjustments with movement speed and accuracy.

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    Bertucco, M; Cesari, P

    2010-11-24

    We wanted to determine whether movement planning followed Fitts' law by investigating the relationship between movement planning and movement performance in experienced dancers executing a typical classical ballet step in which the big toe was pointed to targets at different distances and of different widths so as to obtain several indices of difficulty (ID). Movement time, velocity and variability at the target were the variables of movement performance kinematics; movement planning was evaluated by analysis of anticipatory postural adjustments (APAs) to assess their modulation at different IDs. Movement time and peak of velocity were found to scale with the ID only when individual movement distance across target widths was entered into the analysis. APA magnitude and duration both scaled according to movement parameters but not in the same way. APA magnitude scaled with movement velocity, while APA duration was sensitive to the amplitude-to-accuracy ratio following the ID for movements performed in the shortest time interval when on-line feedback control is probably not available. Here we show that timing of muscle activation acts as an independent central command that triggers fine-tuning for speed-accuracy trade-off.

  7. Anticipatory postural adjustments to arm movement reveal complex control of paraspinal muscles in the thorax.

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    Lee, Linda-Joy; Coppieters, Michel W; Hodges, Paul W

    2009-02-01

    Anatomical and empirical data suggest that deep and superficial muscles may have different functions for thoracic spine control. This study investigated thoracic paraspinal muscle activity during anticipatory postural adjustments associated with arm movement. Electromyographic (EMG) recordings were made from the right deep (multifidus/rotatores) and superficial (longissimus) muscles at T5, T8, and T11 levels using fine-wire electrodes. Ten healthy participants performed fast unilateral and bilateral flexion and extension arm movements in response to a light. EMG amplitude was measured during 25ms epochs for 150ms before and 400ms after deltoid EMG onset. During arm flexion movements, multifidus and longissimus had two bursts of activity, one burst prior to deltoid and a late burst. With arm extension both muscles were active in a single burst after deltoid onset. There was differential activity with respect to direction of trunk rotation induced by arm movement. Right longissimus was most active with left arm movements and right multifidus was most active with right arm movements. All levels of the thorax responded similarly. We suggest that although thoracic multifidus and longissimus function similarly to control sagittal plane perturbations, these muscles are differentially active with rotational forces on the trunk.

  8. Anticipatory control of center of mass and joint stability during voluntary arm movement from a standing posture: interplay between active and passive control.

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    Patla, Aftab E; Ishac, Milad G; Winter, David A

    2002-04-01

    Anticipatory control of upright posture is the focus of this study that combines experimental and modeling work. Individuals were asked to raise or lower their arms from two initial postures such that the final posture of the arm was at 90 degrees with respect to the body. Holding different weights in the hand varied the magnitude of perturbation to postural stability generated by the arm movement. Whole body kinematics and ground reaction forces were measured. Inverse dynamic analysis was used to determine the internal joint moments at the shoulder, hip, knee and ankle, and reaction forces at the shoulder. Center of mass (COM) of the arm, posture (rest of the body without the arms) and whole body (net COM) were also determined. Changes in joint moment at the hip, knee and ankle revealed a significant effect of the direction of movement. The polarities of the joint moment response were appropriate for joint stabilization. Net COM change showed a systematic effect of the direction of movement even though the arm COM was displaced by the same amount and in the same direction for both arm raising and lowering conditions. In order to determine the effects of the passive forces and moments on the posture COM, the body was modeled as an inverted pendulum. The model was customized for each participant; the relevant model parameters were estimated from data obtained from each trial. The ankle joint stiffness and viscosity were adjusted to ensure postural equilibrium prior to arm movement. Joint reactive forces and moments generated by the arm movements were applied at the shoulder level of this inverted pendulum; these were the only inputs and no active control was included. The posture COM profile from the model simulation was calculated. Results show that simulated posture COM profile and measured posture COM profile are identical for about 200 ms following the onset of arm movement and then they deviate. Therefore, the initial control of COM is passive in nature and the

  9. Anticipatory postural adjustments in reach-to-grasp: effect of object mass predictability.

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    Aimola, Ettore; Santello, Marco; La Grua, Giovanni; Casabona, Antonino

    2011-09-15

    Anticipatory postural adjustments (APAs) are thought to compensate for upcoming and predictable perturbations before they occur, e.g., a backward shift of the body center of pressure (COP) before raising the arm. When the goal of arm movements is to reach, grasp, and manipulate an object, predicting the effect of raising the arm on body COP before reach onset could incorporate the properties of the object to be lifted, as both will affect postural control during reaching and object manipulation. Alternatively, the central nervous system (CNS) might use separate APAs to compensate for the effect of arm raising from raising the arm and object. To distinguish between these two scenarios, we asked subjects to reach, grasp, and lift an object whose mass (100g, 750g, or 1400g) was either constant across trials or variable from trial to trial ('predictable' and 'unpredictable' condition, respectively). We hypothesized that object mass would affect the magnitude of APAs in the predictable condition before the onset of object lift but not before the initial arm onset. We also expected COP variability following object lift to be reduced as a result of APAs. For the unpredictable condition, we expected 'default' APAs that would minimize postural perturbation following object lift. We found that both magnitude and timing of APAs were modulated as a function of predictable object mass prior to contact, rather than at the onset of the reaching movement. Specifically, COP position moved forward with increasing object load (p<0.05) and peak COP velocity related to object contact occurred significantly early for heavier loads (p<0.05). For the random condition, the COP position and timing at all loads resembled that associated with larger predictable loads. These findings suggest that modulating COP to a future event might be more accurate when timed to temporally close events, thus potentially reducing the computational load as well as risks of prediction errors. Additionally, our

  10. Independent walking as a major skill for the development of anticipatory postural control: evidence from adjustments to predictable perturbations.

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    Cignetti, Fabien; Zedka, Milan; Vaugoyeau, Marianne; Assaiante, Christine

    2013-01-01

    Although there is suggestive evidence that a link exists between independent walking and the ability to establish anticipatory strategy to stabilize posture, the extent to which this skill facilitates the development of anticipatory postural control remains largely unknown. Here, we examined the role of independent walking on the infants' ability to anticipate predictable external perturbations. Non-walking infants, walking infants and adults were sitting on a platform that produced continuous rotation in the frontal plane. Surface electromyography (EMG) of neck and lower back muscles and the positions of markers located on the platform, the upper body and the head were recorded. Results from cross-correlation analysis between rectified and filtered EMGs and platform movement indicated that although muscle activation already occurred before platform movement in non-walking infants, only walking infants demonstrated an adult-like ability for anticipation. Moreover, results from further cross-correlation analysis between segmental angular displacement and platform movement together with measures of balance control at the end-points of rotation of the platform evidenced two sorts of behaviour. The adults behaved as a non-rigid non-inverted pendulum, rather stabilizing head in space, while both the walking and non-walking infants followed the platform, behaving as a rigid inverted pendulum. These results suggest that the acquisition of independent walking plays a role in the development of anticipatory postural control, likely improving the internal model for the sensorimotor control of posture. However, despite such improvement, integrating the dynamics of an external object, here the platform, within the model to maintain balance still remains challenging in infants.

  11. Independent walking as a major skill for the development of anticipatory postural control: evidence from adjustments to predictable perturbations.

    Directory of Open Access Journals (Sweden)

    Fabien Cignetti

    Full Text Available Although there is suggestive evidence that a link exists between independent walking and the ability to establish anticipatory strategy to stabilize posture, the extent to which this skill facilitates the development of anticipatory postural control remains largely unknown. Here, we examined the role of independent walking on the infants' ability to anticipate predictable external perturbations. Non-walking infants, walking infants and adults were sitting on a platform that produced continuous rotation in the frontal plane. Surface electromyography (EMG of neck and lower back muscles and the positions of markers located on the platform, the upper body and the head were recorded. Results from cross-correlation analysis between rectified and filtered EMGs and platform movement indicated that although muscle activation already occurred before platform movement in non-walking infants, only walking infants demonstrated an adult-like ability for anticipation. Moreover, results from further cross-correlation analysis between segmental angular displacement and platform movement together with measures of balance control at the end-points of rotation of the platform evidenced two sorts of behaviour. The adults behaved as a non-rigid non-inverted pendulum, rather stabilizing head in space, while both the walking and non-walking infants followed the platform, behaving as a rigid inverted pendulum. These results suggest that the acquisition of independent walking plays a role in the development of anticipatory postural control, likely improving the internal model for the sensorimotor control of posture. However, despite such improvement, integrating the dynamics of an external object, here the platform, within the model to maintain balance still remains challenging in infants.

  12. Anticipatory postural muscle activity associated with bilateral arm flexion while standing in individuals with spastic diplegic cerebral palsy: A pilot study.

    Science.gov (United States)

    Tomita, Hidehito; Fukaya, Yoshiki; Honma, Shota; Ueda, Tomomi; Yamamoto, Yoshiji; Shionoya, Katsuyoshi

    2010-07-26

    Compared to automatic postural responses to external perturbation, little is known about anticipatory postural adjustments in individuals with spastic diplegic cerebral palsy. In this study, we examined whether anticipatory activation of postural muscles would be observed before voluntary arm movement while standing in individuals with spastic diplegia. Seven individuals with spastic diplegia (SDCP(group), 12-22 years) and 7 age- and gender-matched individuals without disability (Control(group)) participated in this study. Participants performed bilateral arm flexion at maximum speed at their own timing while standing, during which electromyographic (EMG) activities of focal and postural muscles were recorded. In both groups, the erector spinae (ES) and medial hamstring (MH) muscles were activated in advance of the anterior deltoid muscle (AD), which is a focal muscle of arm flexion. Although start times of ES and MH with respect to AD were similar in the 2 groups, increases in EMG amplitudes of ES and MH in the anticipatory range from -150ms to +50ms, with respect to burst onset of AD, were significantly smaller in the SDCP(group) than in the Control(group). These findings suggest that individuals with spastic diplegia have the ability to anticipate the effects of disturbance of posture and equilibrium caused by arm movement and to activate postural muscles in advance of focal muscles. However, it is likely that the anticipatory increase in postural muscle activity is insufficient in individuals with spastic diplegia.

  13. Decoupling of stretch reflex and background muscle activity during anticipatory postural adjustments in humans.

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    Vedula, Siddharth; Kearney, Robert E; Wagner, Ross; Stapley, Paul J

    2010-08-01

    We studied the evolution of stretch reflexes in relation to background electromyographic (EMG) activity in the soleus muscle preceding the onset of voluntary arm raise movements. Our objective was to investigate if changes in reflex EMG and muscle activity occur simultaneously and are similarly scaled in amplitude. Ten human subjects stood with each foot on pedals able to exert short dorsiflexor pulses during stance. Subjects were asked to product consistent voluntary arm raise movements to a target upon a visual cue. In (1/4) of trials, no pulse perturbations were given, but in the remaining (3/4)'s of all trials pulses were given randomly during a 600-ms period, from 400 ms before until 200 ms after the onset of the movements. Perturbation trials were sorted into 20-ms bins post hoc, and the amplitude of the reflex EMG component was calculated and compared to the EMG activity obtained when no pulses were given. Results showed that despite exhibiting similar profiles over time, the background EMG consistently inhibited before the reflex EMG did. However, times of reactivation (rebound) were variable across subjects, with background EMG activating before reflex for some subjects and vice versa for others. The minimum values of inhibition, time of inhibition and time of rebound for background and reflex EMG measures did not show significant linear correlations when all subjects' data were considered. These results suggest that reflex and background EMG components of anticipatory postural adjustments evolve differently in time and amplitude. This has implications for the independent control of reflexes and voluntary muscle activity.

  14. 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.

  15. A method to model anticipatory postural control in driver braking events

    NARCIS (Netherlands)

    Osth, J.; Eliasson, E.; Happee, R.; Brolin, K.

    2014-01-01

    Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated brakin

  16. The use of cognitive cues for anticipatory strategies in a dynamic postural control task - validation of a novel approach to dual-task testing

    DEFF Research Database (Denmark)

    Læssøe, Uffe; Grarup, Bo; Bangshaab, Jette

    2016-01-01

    Introduction: Dual-task testing is relevant in the assessment of postural control. A combination of a primary (motor) and a secondary (distracting cognitive) tasks is most often used. It remains a challenge however, to standardize and monitor the cognitive task. In this study a new dual......-task testing approach with a facilitating, rather than distracting, cognitive component was evaluated. Methods: Thirty-one community-dwelling elderly and fifteen young people were tested with respect to their ability to use anticipatory postural control strategies. The motor task consisted of twenty...... two sessions. Conclusion: The dual-task test was sensitive enough to discriminate between elderly and young people. It revealed that the elderly did not utilize cognitive cues for their anticipatory postural control strategies as well as the young were able to. The test procedure was feasible...

  17. Anticipatory Posturing of the Vocal Tract Reveals Dissociation of Speech Movement Plans from Linguistic Units

    OpenAIRE

    Sam Tilsen; Pascal Spincemaille; Bo Xu; Peter Doerschuk; Wen-Ming Luh; Elana Feldman; Yi Wang

    2016-01-01

    Models of speech production typically assume that control over the timing of speech movements is governed by the selection of higher-level linguistic units, such as segments or syllables. This study used real-time magnetic resonance imaging of the vocal tract to investigate the anticipatory movements speakers make prior to producing a vocal response. Two factors were varied: preparation (whether or not speakers had foreknowledge of the target response) and pre-response constraint (whether or ...

  18. Anticipatory postural activity of the deep trunk muscles differs between anatomical regions based on their mechanical advantage.

    Science.gov (United States)

    Park, R J; Tsao, H; Cresswell, A G; Hodges, P W

    2014-03-07

    The functional differentiation between regions of psoas major (PM) and quadratus lumborum (QL) may underlie a mechanical basis for recruitment of motor units across the muscle. These mechanically unique fascicle regions of these complex multifascicular muscles, PM and QL, are likely to be controlled independently by the central nervous system (CNS). Fine-wire electrodes recorded the electromyographic activity of the PM fascicles arising from the transverse process (PM-t) and vertebral body (PM-v) and the anterior (QL-a) and posterior (QL-p) layers of QL on the right side during a postural perturbation associated with rapid arm movements. The findings of this study indicate that the CNS coordinates the activity of specific regions of PM and QL independently as a component of the anticipatory postural adjustments that precedes the predictable challenge to the spine associated with limb movements. The spatial and temporal features of discrete activity of different regions within PM and QL matched their differing mechanical advantage predicted from their anatomy. These findings suggest that the CNS differentially activates individual regions within complex spine muscles to control the three-dimensional forces applied to the spine. The data also point to a sophisticated control of muscle activation that appears based on mechanical advantage.

  19. Unexperienced mechanical effects of muscular fatigue can be predicted by the Central Nervous System as revealed by anticipatory postural adjustments.

    Science.gov (United States)

    Monjo, Florian; Forestier, Nicolas

    2014-09-01

    Muscular fatigue effects have been shown to be compensated by the implementation of adaptive compensatory neuromuscular strategies, resulting in modifications of the initial motion coordination. However, no studies have focused on the efficiency of the feedforward motor commands when muscular fatigue occurs for the first time during a particular movement. This study included 18 healthy subjects who had to perform arm-raising movements in a standing posture at a maximal velocity before and after a fatiguing procedure involving focal muscles. The arm-raising task implies the generation of predictive processes of control, namely Anticipatory Postural Adjustments (APAs), whose temporal and quantitative features have been shown to be dependent on the kinematics of the upcoming arm-raising movement. By altering significantly the kinematic profile of the focal movement with a fatiguing procedure, we sought to find out whether APAs scaled to the lower mechanical disturbance. APAs were measured using surface electromyography. Following the fatiguing procedure, acceleration peaks of the arm movement decreased by ~27%. APAs scaled to this lower fatigue-related disturbance during the very first trial post-fatigue, suggesting that the Central Nervous System can predict unexperienced mechanical effects of muscle fatigue. It is suggested that these results are accounted for by prediction processes in which the central integration of the groups III and IV afferents leads to an update of the internal model by remapping the relationship between focal motor command magnitude and the actual mechanical output.

  20. Fear of falling is associated with prolonged anticipatory postural adjustment during gait initiation under dual-task conditions in older adults.

    Science.gov (United States)

    Uemura, Kazuki; Yamada, Minoru; Nagai, Koutatsu; Tanaka, Buichi; Mori, Shuhei; Ichihashi, Noriaki

    2012-02-01

    Little is known about dynamic balance control under dual-task conditions in older adults with fear of falling (FoF). The purpose of this study was to examine the effect of FoF on anticipatory postural adjustment (APA) during gait initiation under dual-task conditions in older adults. Fifty-seven elderly volunteers (age, 79.2 [6.8] years) from the community participated in this study. Each participant was categorised into either the Fear (n=24) or No-fear (n=33) group on the basis of the presence or absence of FoF. Under single- and dual-task conditions, centre of pressure (COP) data were collected while the participants performed gait initiation trials from a starting position on a force platform. We also performed a 10-m walking test (WT), a timed up & go test (TUG), and a functional reach test (FR). The reaction and APA phases were measured from the COP data. The results showed that under the dual-task condition, the Fear group had significantly longer APA phases than the No-fear group, although no significant differences were observed between the 2 groups in the reaction and APA phases under the single-task condition and in any clinical measurements (WT, TUG, and FR). Our findings suggest that specific deficits in balance control occur in subjects with FoF during gait initiation while dual tasking, even if their physical functions are comparable to subjects without FoF.

  1. Effects of stance width on postural movement pattern and anticipatory postural control associated with unilateral arm abduction.

    Science.gov (United States)

    Fujiwara, Katsuo; Tomita, Hidehito; Kurokawa, Nozomi; Asai, Hitoshi; Maeda, Kaoru

    2009-06-01

    We investigated the effects of stance width on postural movement pattern and activation timing of postural muscles during unilateral arm abduction. Thirty-two healthy subjects abducted the right arm at their own timing. Stance width was 0, 9, 18 or 27 cm. Movement angles of leg lateral inclination and trunk lateral flexion to the leg in the frontal plane were analyzed. Based on movement angles at 0 cm width, subjects were classified into three groups: contralateral whole body leaning (CWBLg); ipsilateral trunk flexion (ITFg); and contralateral trunk flexion (CTFg). A high correlation between the movement angles was obtained at 0 cm width (r=0.82). With increasing stance width, postural movement pattern in the ITFg shifted to patterns characterized by lateral flexion of the trunk toward the side opposite to arm movement, and movement angle of leg-inclination in ITFg and CWBLg decreased. At 0 cm width, left gluteus medius and tensor fascia latae were activated significantly about 40 ms ahead of the right middle deltoid in CWBLg and CTFg, but not in ITFg. However, preceding activation became prominent (about 20 ms) in ITFg for wide stances. Moreover, bilateral activation of the tensor fascia latae was observed in CTFg for all widths.

  2. Effects of neck flexion on discriminative and cognitive processing in anticipatory postural control during bilateral arm movement.

    Science.gov (United States)

    Fujiwara, Katsuo; Yaguchi, Chie; Kunita, Kenji; Mammadova, Aida

    2012-06-19

    We investigated the effect of neck flexion on discriminative and cognitive processing in postural control during bilateral arm movement while standing, using event-related potential (ERP) and electromyogram. Fourteen healthy subjects flexed their arms to the target stimuli with a 20% probability in neck resting and flexion positions. Amplitude and latency of N2 and P3, anterior deltoid (AD) reaction time, onset time of postural muscles with respect to AD activation, and peak amplitude and latency of all muscles were measured. With neck flexion, N2 and P3 amplitudes increased, N2 and P3 latencies and AD reaction time shortened, and onset times of all postural muscles became earlier. No significant differences in peak amplitude and latency of each muscle were found between neck positions. Significant positive correlations were found in changes with neck flexion between P3 latency and AD reaction time, and between N2 latency and onset time of erector spinae. These suggest that with neck flexion, attention allocation to discriminative and cognitive processing increased, and the processing speed increased with shortening of reaction time in focal muscles. In addition, the onset time of postural muscles became earlier without changing the activation pattern, which was associated with the hastened discriminative processing.

  3. Deficits in anticipatory inhibition of postural muscle activity associated with load release while standing in individuals with spastic diplegic cerebral palsy.

    Science.gov (United States)

    Tomita, Hidehito; Fukaya, Yoshiki; Totsuka, Kenji; Tsukahara, Yuri

    2013-04-01

    This study aimed to determine whether individuals with spastic diplegic cerebral palsy (SDCP) have deficits in anticipatory inhibition of postural muscle activity. Nine individuals with SDCP (SDCP group, 3 female and 6 male, 13-24 yr of age) and nine age- and sex-matched individuals without disability (control group) participated in this study. Participants stood on a force platform, which was used to measure the position of the center of pressure (CoP), while holding a light or heavy load in front of their bodies. They then released the load by abducting both shoulders. Surface electromyograms were recorded from the rectus abdominis, erector spinae (ES), rectus femoris (RF), medial hamstring (MH), tibialis anterior (TA), and gastrocnemius (GcM) muscles. In the control group, anticipatory inhibition before load release and load-related modulation of the inhibition were observed in all the dorsal muscles recorded (ES, MH, and GcM). In the SDCP group, similar results were obtained in the trunk muscle (ES) but not in the lower limb muscles (MH and GcM), although individual differences were seen, especially in MH. Anticipatory activation of the ventral lower limb muscles (RF and TA) and load-related modulation of the activation were observed in both participant groups. CoP path length during load release was longer in the SDCP group than in the control group. The present findings suggest that individuals with SDCP exhibit deficits in anticipatory inhibition of postural muscles at the dorsal part of the lower limbs, which is likely to result in a larger disturbance of postural equilibrium.

  4. Anticipatory postural adjustments are unaffected by age and are not absent in patients with the freezing of gait phenomenon.

    Science.gov (United States)

    Plate, A; Klein, K; Pelykh, O; Singh, A; Bötzel, K

    2016-09-01

    In bipedal gait, the initiation of the first step is preceded by a complex sequence of movements which shift the centre of mass of the body towards the stance foot to allow for a step of the swing foot. These anticipatory postural adjustments (APAs) have been investigated in order to elucidate movement strategies in healthy and diseased persons. We studied the influence of several external parameters (age, type of step initiation) on APAs and investigated whether Parkinsonian patients may have different APAs. As a result, we found that externally elicited steps were preceded by faster and larger APAs than self-timed steps. Parkinsonian patients without the freezing of gait (FOG) phenomenon showed overall slightly reduced APAs but did not clearly differ from patients with FOG. Multiple APAs were seen in up to 25 % of the steps of the patients and in a much lower percentage of the steps of control subjects. The results indicate that APAs are significantly influenced by the timing of a step, i.e. are larger in externally elicited steps. The patients showed an overall preserved APA pattern but slowed movements and amplitude, indicating that increased bradykinesia due to progressive illness is a plausible explanation for these findings. The freezing phenomenon is not explained by a general absence or massive reduction in APA measures.

  5. Balance control in aging: improvements in anticipatory postural adjustments and updating of internal models.

    Science.gov (United States)

    Kubicki, Alexandre; Mourey, France; Bonnetblanc, François

    2015-12-07

    Postural stability of older subjects can be estimated during orthostatic equilibrium. However, dynamic equilibrium is also important to investigate risks of fall. It implies different interpretations of measures given by force plates. Same dependant variables (e.g. center of pressure displacement) cannot be interpreted the same ways depending of the type of equilibrium that is investigated. In particular, sways increases during dynamic equilibrium and before movement execution may reflect an improvement of feedforward control.

  6. 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.

  7. First trial postural reactions to unexpected balance disturbances: a comparison with the acoustic startle reaction.

    Science.gov (United States)

    Oude Nijhuis, Lars B; Allum, John H J; Valls-Solé, Josep; Overeem, Sebastiaan; Bloem, Bastiaan R

    2010-11-01

    Unexpected support-surface movements delivered during stance elicit "first trial" postural reactions, which are larger and cause greater instability compared with habituated responses. The nature of this first trial reaction remains unknown. We hypothesized that first trial postural reactions consist of a generalized startle reaction, with a similar muscle synergy as the acoustic startle response, combined with an automatic postural reaction. Therefore we compared acoustic startle responses to first trial postural reactions. Eight healthy subjects stood on a support surface that unexpectedly rotated backwards 10 times, followed by 10 startling acoustic stimuli, or vice versa. Outcome measures included full body kinematics and surface EMG from muscles involved in startle reactions or postural control. Postural perturbations and startling acoustic stimuli both elicited a clear first trial reaction, as reflected by larger kinematic and EMG responses. The ensuing habituation rate to repeated identical stimuli was comparable for neck and trunk muscles in both conditions. Onset latencies in neck muscles occurred significantly later for first trial perturbations compared with startle responses, but earlier in trunk muscles. Our results show that platform tilting initially induces reactions larger than needed to maintain equilibrium. For neck and trunk muscles, these first trial postural reactions resembled acoustic startle reflexes. First trial postural reactions may be triggered by interaction of afferent volleys formed by somatosensory and vestibular inputs. Acoustic startle reactions may also be partially triggered by vestibular inputs. Similar muscle activation driven by vestibular inputs may be the common element of first trial postural responses and acoustic startle reactions.

  8. First trial postural reactions to unexpected balance disturbances: a comparison with the acoustic startle reaction.

    NARCIS (Netherlands)

    Oude Nijhuis, L.B.; Allum, J.H.J.; Valls-Sole, J.; Overeem, S.; Bloem, B.R.

    2010-01-01

    Unexpected support-surface movements delivered during stance elicit "first trial" postural reactions, which are larger and cause greater instability compared with habituated responses. The nature of this first trial reaction remains unknown. We hypothesized that first trial postural reactions consis

  9. Postural reactions to neck vibration in Parkinson's disease.

    Science.gov (United States)

    Valkovic, Peter; Krafczyk, Siegbert; Saling, Marian; Benetin, Ján; Bötzel, Kai

    2006-01-01

    To test the hypothesis that reduced reactions to proprioceptive input signals contribute to postural instability in Parkinson's disease (PD), pulses of mechanical vibration were applied to the neck muscles of PD patients and healthy controls. This stimulus elicits postural reactions in standing subjects. Participating were 13 moderately affected PD patients, 13 severely affected PD patients, and 13 age-matched healthy subjects. Patients were tested on and off medication. Three-second-long pulses of vibration were regularly (10 times) applied to the posterior neck muscles while subjects kept their eyes open or closed. Postural responses to the stimuli were measured by static posturography. No intergroup difference in the pattern and latencies of responses was found. However, the amplitudes of the postural reactions (shift of center of foot pressure) were significantly larger in advanced PD patients; those of moderately affected PD patients did not differ from those of control subjects. Moreover, the size of postural responses in both latter groups decreased across the trial contrary to that of advanced PD patients. Comparison of the measures during on and off testing revealed no significant differences. These results indicate that neither afferent proprioceptive deficits nor central integrative functions but rather scaling and habituation of erroneous proprioceptive information are disturbed in the postural control of advanced PD. Nondopaminergic structures seem to be responsible for this impairment.

  10. 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

  11. Ajustes posturais antecipatórios e compensatórios ao pegar uma bola em condição de estabilidade e instabilidade postural Anticipatory and compensatory postural adjustments during catching a ball in condition of postural instability and stability

    Directory of Open Access Journals (Sweden)

    Vanessa Scariot

    2012-09-01

    Full Text Available Indivíduos jovens pré-selecionam suas estratégias de ajuste postural antes que uma perturbação externa ocorra, com base nas características da tarefa. Entretanto, ainda não é bem conhecido de que maneira o sistema nervoso central lida com os ajustes posturais antecipatórios e compensatórios, mediante alguns treinos de equilíbrio que são comumente usados na prática clínica da Fisioterapia. Treze adultos jovens receberam 20 perturbações posturais externas de pegar uma bola arremessada pelo experimentador sobre condições de estabilidade e instabilidade postural (sobre uma espuma. As atividades eletromiográficas dos músculos tríceps braquial (músculo focal, retoabdominal e paravertebral lombar foram avaliadas nas janelas de tempo típicas dos ajustes posturais antecipatórios e compensatórios, assim como o pico do deslocamento do centro de pressão corporal após a perturbação. A magnitude das integrais da atividade eletromiográfica do músculo tríceps braquial foi significativamente menor em condição de instabilidade postural, não houve diferença estatística entre as condições para as integrais da atividade eletromiográfica dos músculos retoabdominal e paravertebral lombar. O pico do deslocamento anteroposterior do centro de pressão corporal foi similar entre as duas condições. Treino de equilíbrio associado à perturbação externa da postura sobre espuma pode não ser mais eficaz ou eficiente do que sobre uma superfície estável, quando se pretende alterar a atividade dos músculos posturais do tronco. Além disso, este tipo de intervenção pode corroborar para diminuir a ativação antecipatória (ajustes posturais antecipatórios do músculo focal.Young individuals preselect their postural adjustment strategies before an external perturbation, based on the characteristics of the task. However, it is not well documented how the central nervous system deals with anticipatory and compensatory postural

  12. Higher precision in pointing movements of the preferred vs. non-preferred hand is associated with an earlier occurrence of anticipatory postural adjustments

    Directory of Open Access Journals (Sweden)

    Carlo Bruttini

    2016-07-01

    Full Text Available It is a common experience to exhibit a greater dexterity when performing a pointing movement with the preferred limb vs. the non-preferred one. Here we provide evidence that the higher precision in pointing movements of the preferred vs. non-preferred hand is associated with an earlier occurrence of the Anticipatory Postural Adjustments (APAs.In this aim, we compared the APAs which stabilize the left or the right arm when performing a pen-pointing movement (prime mover Flexor Carpi Radialis. Moreover, we analysed the elbow and wrist kinematics as well as the precision of the pointing movement. The mean kinematics of wrist movement and its latency, with respect to prime mover recruitment, were similar in the two sides, while APAs in Triceps Brachii, Biceps Brachii and Anterior Deltoid were more anticipated when movements were performed with the preferred than with the non-preferred hand (60-70 vs. 20-30 ms. APAs amplitudes were comparable in the muscles of the two sides. Earlier APAs in the preferred limb were associated with a better fixation of the elbow, which showed a lower excursion, and with a less scattered pointing error (preferred: 10.1 ± 0.8 mm; non-preferred: 16.3 ± 1.7.Present results suggest that, by securing the more proximal joints dynamics, an appropriate timing of the intra-limb APAs is necessary for refining the voluntary movement precision, which is known to be scarce on the non-preferred side.

  13. Estimation of sitting posture by using the combination of ground reaction force

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hye Ob; Park, Suk Yung [KAIST, Daejeon (Korea, Republic of)

    2015-04-15

    To avoid back pain and related diseases, an appropriate sitting posture should be maintained. Inertial measurement units (IMUs) or marker-less motion cameras, such as Kinect, has recently been used to achieve simpler posture measurements than optical motion capture camera systems. However, multiple IMUs can affect the natural posture of users. The space requirement to guarantee reliable camera data is also somewhat excessive (>1 m) for some personal space setups. Therefore, we propose an unobtrusive method for estimating sitting posture on the basis of ground reaction force measurement, which can be achieved without the use of markers or additional space for measurement. To eliminate additional measurement information other than the ground reaction force underneath the chair and desk, we modeled the posture as a multi-segment rigid body. Several assumptions were proposed and verified to simplify the model and data processing without deteriorating the posture information. Furthermore, to examine whether the combined GRF information provides the appropriateness of the posture, we performed sitting tests for various postures. Results showed that the combinations of GRF measurement could reasonably estimate the sitting posture by the simplified rigid body model and could reliably differentiate the inappropriate forward bent posture. The results showed that the proposed method could serve as a sensing mechanism of posture monitoring systems.

  14. Core Muscle Response Times and Postural Reactions in Soccer Players and Nonplayers

    NARCIS (Netherlands)

    Borghuis, Arend Jan; Lemmink, Koen A. P. M.; Hof, At L.

    2011-01-01

    BORGHUIS, A. J., K. A. P. M. LEMMINK, and A. L. HOF. Core Muscle Response Times and Postural Reactions in Soccer Players and Nonplayers. Med. Sci. Sports Exerc., Vol. 43, No. 1, pp. 108-114, 2011. Decreased core stability has been suggested to be associated with a higher occurrence of lower extremit

  15. Investigation of spinal posture signatures and ground reaction forces during landing in elite female gymnasts.

    Science.gov (United States)

    Wade, Melanie; Campbell, Amity; Smith, Anne; Norcott, Joanne; O'Sullivan, Peter

    2012-12-01

    The link between static and dynamic landing lumbar postures, when gymnasts are exposed to large ground reaction forces, has not been established. This investigation aimed to (a) determine if a relationship exists between sagittal static and dynamic landing lumbar spine angles at peak ground reaction force (GRF) and (b) quantify how close to end-range postures the gymnasts were at landing peak GRF. Twenty-one female gymnasts' upper and lower lumbar spine angles were recorded: statically in sitting and standing, during landing of three gymnastic skills, and during active end-range lumbar flexion. Pearson's correlations were used to investigate relationships between the angles in different postures. Significant correlations (r = .77-.89, p postures in the lower lumbar spine angle, while fewer and less significant upper lumbar spine correlations were reported. Thirty percent of gymnasts landed a backsault with their lower lumbar spine flexed beyond their active end-range while experiencing GRF 6.8-13.3 times their body weight. These results inform low back pain prevention and management strategies in this population and highlight areas for future research.

  16. Ground Reaction Forces Generated by Twenty-eight Hatha Yoga Postures.

    Science.gov (United States)

    Wilcox, Sylvia J; Hager, Ron; Lockhart, Barbara; Seeley, Matthew K

    Adherents claim many benefits from the practice of yoga, including promotion of bone health and prevention of osteoporosis. However, no known studies have investigated whether yoga enhances bone mineral density. Furthermore, none have estimated reaction forces applied by yoga practitioners. The purpose of this study was to collect ground reaction force (GRF) data on a variety of hatha yoga postures that would commonly be practiced in fitness centers or private studios. Twelve female and eight male volunteers performed a sequence of 28 hatha yoga postures while GRF data were collected with an AMTI strain-gauge force platform. The sequence was repeated six times by each study subject. Four dependent variables were studied: peak vertical GRF, mean vertical GRF, peak resultant GRF, and mean resultant GRF. Univariate analysis was used to identify mean values and standard deviations for the dependent variables. Peak vertical and resultant values of each posture were similar for all subjects, and standard deviations were small. Similarly, mean vertical and resultant values were similar for all subjects. This 28 posture yoga sequence produced low impact GRF applied to upper and lower extremities. Further research is warranted to determine whether these forces are sufficient to promote osteogenesis or maintain current bone health in yoga practitioners.

  17. 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.

  18. 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).

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

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

    2008-04-01

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

  20. Postural stability, clicker reaction time and bow draw force predict performance in elite recurve archery.

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    Spratford, Wayne; Campbell, Rhiannon

    2017-02-14

    Recurve archery is an Olympic sport that requires extreme precision, upper body strength and endurance. The purpose of this research was to quantify how postural stability variables both pre- and post-arrow release, draw force, flight time, arrow length and clicker reaction time, collectively, impacted on the performance or scoring outcomes in elite recurve archery athletes. Thirty-nine elite-level recurve archers (23 male and 16 female; mean age = 24.7 ± 7.3 years) from four different countries volunteered to participate in this study prior to competing at a World Cup event. An AMTI force platform (1000Hz) was used to obtain centre of pressure (COP) measurements 1s prior to arrow release and 0.5s post-arrow release. High-speed footage (200Hz) allowed for calculation of arrow flight time and score. Results identified clicker reaction time, draw force and maximum sway speed as the variables that best predicted shot performance. Specifically, reduced clicker reaction time, greater bow draw force and reduced postural sway speed post-arrow release were predictors of higher scoring shots. It is suggested that future research should focus on investigating shoulder muscle tremors at full draw in relation to clicker reaction time, and the effect of upper body strength interventions (specifically targeting the musculature around the shoulder girdle) on performance in recurve archers.

  1. Reaction null-space filter: extracting reactionless synergies for optimal postural balance from motion capture data.

    Science.gov (United States)

    Nenchev, D N; Miyamoto, Y; Iribe, H; Takeuchi, K; Sato, D

    2016-01-01

    This paper introduces the notion of a reactionless synergy: a postural variation for a specific motion pattern/strategy, whereby the movements of the segments do not alter the force/moment balance at the feet. Given an optimal initial posture in terms of stability, a reactionless synergy can ensure optimality throughout the entire movement. Reactionless synergies are derived via a dynamical model wherein the feet are regarded to be unfixed. Though in contrast with the conventional fixed-feet models, this approach has the advantage of exhibiting the reactions at the feet explicitly. The dynamical model also facilitates a joint-space decomposition scheme yielding two motion components: the reactionless synergy and an orthogonal complement responsible for the dynamical coupling between the feet and the support. Since the reactionless synergy provides the basis (a feedforward control component) for optimal balance control, it may play an important role when evaluating balance abnormalities or when assessing optimality in balance control. We show how to apply the proposed method for analysis of motion capture data obtained from three voluntary movement patterns in the sagittal plane: squat, sway, and forward bend.

  2. Effects of regular Tai Chi practice and jogging on neuromuscular reaction during lateral postural control in older people.

    Science.gov (United States)

    Wang, Shao-Jun; Xu, Dong-Qing; Li, Jing-Xian

    2017-01-01

    This study examined the effects of regular Tai Chi practice and jogging on the neuromuscular activity of the trunk, hip, and ankle joint muscles of older people during lateral postural perturbation. A total of 42 older people participated in the study and formed the Tai Chi, jogging, and sedentary control groups. Electromyography signals were collected from the peroneus longus, anterior tibialis, gluteus medius, and erector spinae during unpredictable mediolateral perturbation. The Tai Chi group exhibited significantly faster latencies of the tibialis anterior and erector spinae than the control group. The jogging group showed a significantly shorter neuromuscular reaction time of the erector spinae than the control group. No significant difference was observed between the Tai Chi and jogging groups. Long-term regular Tai Chi practice enhanced the neuromuscular reaction of the erector spinae and tibialis anterior to lateral perturbation and will help timely posture correction when lateral postural distributions occur.

  3. 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…

  4. The connections between postural reactions, scoliosis postures and scoliosis in girls aged 12-15 years old examined using the Spearman’s Rank OrderCorrelation

    Directory of Open Access Journals (Sweden)

    Wilczyński Jacek

    2016-06-01

    Full Text Available The aim of the research was to analyse the Spearman's Rank Order Correlation between the postural reactions, scoliosis postures and scoliosis in girls aged 12-15 years old. Throughout the whole group of girls, positive correlations between attitude parameters in the frontal plane and the postural reactions were observed: The angle of primary curvature/anteroposterior speed with which eyes closed, angle of primary curvature /average speed with which eyes closed, angle of primary curvature /path length eyes closed, absolute value shoulders angle line/mean loading point X eyes closed, absolute value pelvic inclination angle/lateral speed eyes closed. Negative correlations occurred in cases: absolute value angle of secondary curvature/ mean loading point X eyes open, depth of secondary curvature/mean loading point X eyes open, length of secondary curvature/mean loading point X eyes open, angle of secondary curvature/mean loading point X eyes closed. Statistically significant correlations occurred more frequent when the Romberg’s test was held with eyes closed (CE: angle of primary curvature/anteroposterior speed, torso inclination angle/mean loading point X, angle of primary curvature/average speed, angle of primary curvature/path length, absolute value shoulders angle line/mean loading point X, absolute value pelvic inclination angle/ lateral speed, angle of secondary curvature/mean loading point Y. Among the correlations with eyes closed six were positive: angle of primary curvature/anteroposterior speed, torso inclination angle/mean loading point X, angle of primary curvature/ average speed, angle of primary curvature/ path length, absolute value shoulders angle line/mean loading point X, absolute value pelvic inclination angle/lateral speed, and one was negative: angle of secondary curvature/ mean loading point Y. Among the correlations with eyes open (OE only three negative correlations occurred: absolute value angle of secondary curvature

  5. Adaptability and Prediction of Anticipatory Muscular Activity Parameters to Different Movements in the Sitting Position.

    Science.gov (United States)

    Chikh, Soufien; Watelain, Eric; Faupin, Arnaud; Pinti, Antonio; Jarraya, Mohamed; Garnier, Cyril

    2016-08-01

    Voluntary movement often causes postural perturbation that requires an anticipatory postural adjustment to minimize perturbation and increase the efficiency and coordination during execution. This systematic review focuses specifically on the relationship between the parameters of anticipatory muscular activities and movement finality in sitting position among adults, to study the adaptability and predictability of anticipatory muscular activities parameters to different movements and conditions in sitting position in adults. A systematic literature search was performed using PubMed, Science Direct, Web of Science, Springer-Link, Engineering Village, and EbscoHost. Inclusion and exclusion criteria were applied to retain the most rigorous and specific studies, yielding 76 articles, Seventeen articles were excluded at first reading, and after the application of inclusion and exclusion criteria, 23 were retained. In a sitting position, central nervous system activity precedes movement by diverse anticipatory muscular activities and shows the ability to adapt anticipatory muscular activity parameters to the movement direction, postural stability, or charge weight. In addition, these parameters could be adapted to the speed of execution, as found for the standing position. Parameters of anticipatory muscular activities (duration, order, and amplitude of muscle contractions constituting the anticipatory muscular activity) could be used as a predictive indicator of forthcoming movement. In addition, this systematic review may improve methodology in empirical studies and assistive technology for people with disabilities.

  6. Development of action representation during adolescence as assessed from anticipatory control in a bimanual load-lifting task.

    Science.gov (United States)

    Barlaam, F; Fortin, C; Vaugoyeau, M; Schmitz, C; Assaiante, C

    2012-09-27

    The aim of this study was to explore, during adolescence, alterations in the use of a sensori-motor representation as unveiled by the measurement of anticipatory postural control in a bimanual load-lifting task. We hypothesised that adolescence constitutes a period of refinement of anticipatory postural control due to on-going updates of the body schema and sensori-motor representations. The anticipatory postural control was assessed using a bimanual load-lifting paradigm in which subjects stabilise their left postural forearm, which is supporting an object, while they use their right hand to lift up the object. Kinematics and electromyographic data were recorded in two groups of adolescents (11-13 and 14-16 years of age) and a group of adults. Age and gender effects were tested. During voluntary unloading, the postural forearm stabilisation in adolescents was still different from the adult one, suggesting that further improvement of the postural forearm stabilisation must take place after the age of 16. No differences occur in the two adolescent groups. Moreover, girls presented a better stabilisation of the postural forearm than boys, indicating an earlier refinement of anticipatory postural control. The decrease of activity over postural flexors, which ensure postural stabilisation, appeared later in adolescents with respect to adults. Delayed timing adjustments and increased variability could reflect intense developmental processes underlain by an intense period of CNS maturation during adolescence. We discuss the role of brain maturation in the refinement of sensori-motor representations and the update of body schema.

  7. Anticipatory guidance through DVD.

    Science.gov (United States)

    Franz, Sandra; McMahon, Pamela M; Calongne, Laurinda; Steele-Moses, Susan K

    2014-03-01

    The major purpose of the study was to determine if a 5-minute DVD is an effective method for communicating anticipatory guidance to parents at their child's 4-month well-child visit. A total of 84 caregivers were randomly assigned to receive anticipatory guidance through standard care (written anticipatory guidance handout and free talk) or DVD (DVD format + standard care). Participants completed a brief questionnaire immediately before and after their visit. As anticipated, knowledge scores improved significantly from pre-test to post-test. There was also a significant interaction between format used for anticipatory guidance and time. Specifically, there was greater improvement in knowledge over time for parents in the DVD group as compared with the standard care group. Additionally, the mean knowledge level of those in the DVD group as compared with those in the standard care group trended toward significance. Finally, visit length was shortened by nearly 3 minutes in the DVD group, and close to 100% of all respondents, regardless of anticipatory guidance format, indicated that they were very satisfied with their visit and amount of information learned.

  8. Frequency of anticipatory trunk muscle onsets in children with and without developmental coordination disorder.

    Science.gov (United States)

    Kane, Kyra; Barden, John

    2014-02-01

    This study used electromyography to compare the frequency of anticipatory postural adjustments for three bilateral trunk muscles and unilateral tibialis anterior muscle between children with and without developmental coordination disorder (DCD; n = 22, ages 7 to 14 years) during three tasks (kicking a ball, stepping onto a step, standing on one foot). Between-group comparisons demonstrated significantly less frequent anticipatory activation of ipsilateral tibialis anterior, ipsilateral transversus abdominis/internal oblique, and bilateral external oblique muscles in children with DCD. Odds ratios indicated that children with DCD utilized anticipatory contractions of these muscles one half to one quarter as often as the typically developing children did, while performing the same tasks. These results suggest that the movement difficulties experienced by children with DCD may be associated with less frequent anticipatory adjustments. For these children, inconsistent preparatory activation may contribute to postural control difficulties, excessive movement variability and poor movement quality.

  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. EMG analysis of human postural responses during parabolic flight microgravity episodes

    Science.gov (United States)

    Layne, Charles S.; Spooner, Brian S.

    1990-01-01

    Anticipatory postural activity in the trunk and legs precedes rapid shoulder flexion in unit gravity. The hypothesis that anticipatory activity is a component of a single neural command for arm movement was tested by monitoring the surface electromyographic activity of the biceps femoris, paraspinals, and deltoid muscles of three subjects during the microgravity phase of parabolic flight. If part of a single command, anticipatory postural activity would be expected to remain intact despite the absence of the body's center of gravity in a reduced gravity environment. However, in at least 75 percent of the microgravity trials anticipatory biceps femoris activity was absent, indicating a separation of postural and agonist muscle activity. Such a finding suggests that anticipatory postural biceps femoris activity may be initiated independently of agonist (deltoid) activity.

  11. Effects of backpack weight on posture, gait patterns and ground reaction forces of male children with obesity during stair descent.

    Science.gov (United States)

    Song, Qipeng; Yu, Bing; Zhang, Cui; Sun, Wei; Mao, Dewei

    2014-01-01

    This study investigates the effects of backpack weight on posture, gait pattern, and ground reaction forces for children with obesity in an attempt to define a safe backpack weight limit for them. A total of 16 obese (11.19 ± 0.66 years of age) and 21 normal body weight (11.13 ± 0.69 years of age) schoolboys were recruited. Two force plates and two video cameras were used. Multivariate analysis of variance with repeated measures was employed. Obese children showed increased trunk and head forward inclination angle, gait cycle duration and stance phase, decreased swing phase, and increased ground reaction force in the medial-lateral and anterior-posterior directions when compared with male children with a normal body weight. The changes were observed even with an empty backpack in comparison with normal body weight children and a 15% increase in backpack weight led to further instability and damage on their already strained bodies.

  12. 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.

  13. Effect of expertise in shooting and Taekwondo on bipedal and unipedal postural control isolated or concurrent with a reaction-time task.

    Science.gov (United States)

    Negahban, Hossein; Aryan, Najmolhoda; Mazaheri, Masood; Norasteh, Ali Asghar; Sanjari, Mohammad Ali

    2013-06-01

    It was hypothesized that training in 'static balance' or 'dynamic balance' sports has differential effects on postural control and its attention demands during quiet standing. In order to test this hypothesis, two groups of female athletes practicing shooting, as a 'static balance' sport, and Taekwondo, as a 'dynamic balance' sport, and a control group of non-physically active females voluntarily participated in this study. Postural control was assessed during bipedal and unipedal stance with and without performing a Go/No-go reaction time task. Visual and/or support surface conditions were manipulated in bipedal and unipedal stances in order to modify postural difficulty. Mixed model analysis of variance was used to determine the effects of dual tasking on postural and cognitive performance. Similar pattern of results were found in bipedal and unipedal stances, with Taekwondo practitioners displaying larger sway, shooters displaying lower sway and non-athletes displaying sway characteristics intermediate to Taekwondo and shooting athletes. Larger effect was found in bipedal stance. Single to dual-task comparison of postural control showed no significant effect of mental task on sway velocity in shooters, indicating less cognitive effort invested in balance control during bipedal stance. We suggest that expertise in shooting has a more pronounced effect on decreased sway in static balance conditions. Furthermore, shooters invest less attention in postures that are more specific to their training, i.e. bipedal stance.

  14. Age-related changes in dynamic postural control and attentional demands are minimally affected by local muscle fatigue.

    Directory of Open Access Journals (Sweden)

    Anthony eRemaud

    2016-01-01

    Full Text Available Normal aging results in alterations in the visual, vestibular and somtaosensory systems, which in turn modify the control of balance. Muscle fatigue may exacerbate these age-related changes in sensory and motor functions, and also increase the attentional demands associated with dynamic postural control. The purpose of this study was to investigate the effect of aging on dynamic postural control and posture-related attentional demands before and after a plantar flexor fatigue protocol. Participants (young adults: n=15; healthy seniors: n=13 performed a dynamic postural task along the antero-posterior and the medio-lateral axes, with and without the addition of a simple reaction time task. The dynamic postural task consisted in following a moving circle on a computer screen with the representation of the center of pressure (COP. This protocol was repeated before and after a fatigue task where ankle plantarflexor muscles were targeted. The mean COP-target distance and the mean COP velocity were calculated for each trial. Cross-correlation analyses between the COP and target displacements were also performed. Reaction times were recorded during dual-task trials. Results showed that while young adults adopted an anticipatory control mode to move their COP as close as possible to the target center, seniors adopted a reactive control mode, lagging behind the target center. This resulted in longer COP-target distance and higher COP velocity in the latter group. Concurrently, reaction time increased more in seniors when switching from static stance to dynamic postural conditions, suggesting potential alterations in the central nervous system functions. Finally, plantar flexor muscle fatigue and dual-tasking had only minor effects on dynamic postural control of both young adults and seniors. Future studies should investigate why the fatigue-induced changes in quiet standing postural control do not seem to transfer to dynamic balance tasks.

  15. Self-Described Differences Between Legs in Ballet Dancers: Do They Relate to Postural Stability and Ground Reaction Force Measures?

    Science.gov (United States)

    Mertz, Laura; Docherty, Carrie

    2012-12-01

    Ballet technique classes are designed to train dancers symmetrically, but they may actually create a lateral bias. It is unknown whether dancers in general are functionally asymmetrical, or how an individual dancer's perceived imbalance between legs might manifest itself. The purpose of this study was to examine ballet dancers' lateral preference by analyzing their postural stability and ground reaction forces in fifth position when landing from dance-specific jumps. Thirty university ballet majors volunteered to participate in this study. The subjects wore their own ballet technique shoes and performed fundamental ballet jumps out of fifth position on a force plate. The force plate recorded center of pressure (COP) and ground reaction force (GRF) data. Each subject completed a laterality questionnaire that determined his or her preferred landing leg for ballet jumps, self-identified stronger leg, and self-identified leg with better balance. All statistical comparisons were made between the leg indicated on the laterality questionnaire and the other leg (i.e., if the dancer's response to a question was "left," the comparison was made with the left leg as the "preferred" leg and the right leg as the "non-preferred leg"). No significant differences were identified between the limbs in any of the analyses conducted (all statistical comparisons produced p values > 0.05). The results of this study indicate that a dancer's preferential use of one limb over the other has no bearing on GRFs or balance ability after landing jumps in ballet. Similarly, dancers' opinions of their leg characteristics (such as one leg being stronger than the other) seem not to correlate with the dancers' actual ability to absorb GRFs or to balance when landing from ballet jumps.

  16. Anticipatory Ethics for Emerging Technologies

    NARCIS (Netherlands)

    Brey, P.A.E.

    2012-01-01

    In this essay, a new approach for the ethical study of emerging technology ethics will be presented, called anticipatory technology ethics (ATE). The ethics of emerging technology is the study of ethical issues at the R&D and introduction stage of technology development through anticipation of possi

  17. Delayed inhibition of an anticipatory action during motion extrapolation

    Directory of Open Access Journals (Sweden)

    Riek Stephan

    2010-04-01

    Full Text Available Abstract Background Continuous visual information is important for movement initiation in a variety of motor tasks. However, even in the absence of visual information people are able to initiate their responses by using motion extrapolation processes. Initiation of actions based on these cognitive processes, however, can demand more attentional resources than that required in situations in which visual information is uninterrupted. In the experiment reported we sought to determine whether the absence of visual information would affect the latency to inhibit an anticipatory action. Methods The participants performed an anticipatory timing task where they were instructed to move in synchrony with the arrival of a moving object at a determined contact point. On 50% of the trials, a stop sign appeared on the screen and it served as a signal for the participants to halt their movements. They performed the anticipatory task under two different viewing conditions: Full-View (uninterrupted and Occluded-View (occlusion of the last 500 ms prior to the arrival at the contact point. Results The results indicated that the absence of visual information prolonged the latency to suppress the anticipatory movement. Conclusion We suggest that the absence of visual information requires additional cortical processing that creates competing demand for neural resources. Reduced neural resources potentially causes increased reaction time to the inhibitory input or increased time estimation variability, which in combination would account for prolonged latency.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Anticipatory Eye Movements in Congkak

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    Sheryl Chong

    2011-05-01

    Full Text Available Congkak is a traditional Malaysian board game involving two players taking turns to pick up marbles from a series of holes on the board. We used this game as a model to explore the role of anticipatory eye movements during natural actions (in this case serially picking up/putting marbles as novices learnt the game. Prior work on eye and hand movements in natural behaviour shows that much of the demand on the visual system is computed at the moment it is needed and doesn't depend on information acquired from previous fixations. Vision is driven by the task demands. However, anticipatory fixations to upcoming targets of manipulation have recently been shown to confer spatial accuracy and influence the eye-hand latency. We find that experience with the game also influences the deployment of these anticipatory “look-ahead” fixations, and that their influence on eye-hand latency varies with experience. Results suggest that as our experience in Congkak grows, so does our knowledge of the space relationships necessary for task success.

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

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    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. Salivary a-Amylase Reflects Change in Attentional Demands during Postural Control: Comparison with Probe Reaction Time

    Science.gov (United States)

    Akizuki, Kazunori; Ohashi, Yukari

    2014-01-01

    Purpose: The influence of attention on postural control and the relationship between attention and falling has been reported in previous studies. Although a dual-task procedure is commonly used to measure attentional demand, such procedures are affected by allocation policy, which is a mental strategy to divide attention between simultaneous…

  5. Asymmetries in reactive and anticipatory balance control are of similar magnitude in Parkinson's disease patients.

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    Boonstra, Tjitske A; van Kordelaar, Joost; Engelhart, Denise; van Vugt, Jeroen P P; van der Kooij, Herman

    2016-01-01

    Many Parkinson's disease (PD) patients show asymmetries in balance control during quiet stance and in response to perturbations (i.e., reactive balance control) in the sagittal plane. In addition, PD patients show a reduced ability to anticipate to self-induced disturbances, but it is not clear whether these anticipatory responses can be asymmetric too. Furthermore, it is not known how reactive balance control and anticipatory balance control are related in PD patients. Therefore, we investigated whether reactive and anticipatory balance control are asymmetric to the same extent in PD patients. 14 PD patients and 10 controls participated. Reactive balance control (RBC) was investigated by applying external platform and force perturbations and relating the response of the left and right ankle torque to the body sway angle at the excited frequencies. Anticipatory postural adjustments (APAs) were investigated by determining the increase in the left and right ankle torque just before the subjects released a force exerted with the hands against a force sensor. The symmetry ratio between the contribution of the left and right ankle was used to express the asymmetry in reactive and anticipatory balance control; the correlation between the two ratio's was investigated with Spearman's rank correlation coefficients. PD patients were more asymmetric in anticipatory (p=0.026) and reactive balance control (p=0.004) compared to controls and the symmetry ratios were significantly related (ρ=0.74; p=0.003) in PD patients. These findings suggest that asymmetric reactive balance control during bipedal stance may share a common pathophysiology with asymmetries in the anticipation of voluntary perturbations during, for instance, gait initiation.

  6. Fingertip contact influences human postural control

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    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.

  7. An Anticipatory Model of Cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Dress, W.B., Jr.; Hylton, J.O.; Kercel, S.W.

    1999-04-05

    The Anticipatory System (AS) formalism developed by Robert Rosen provides some insight into the problem of embedding intelligent behavior in machines. AS emulates the anticipatory behavior of biological systems. AS bases its behavior on its expectations about the near future and those expectations are modified as the system gains experience. The expectation is based on an internal model that is drawn from an appeal to physical reality. To be adaptive, the model must be able to update itself. To be practical, the model must run faster than real-time. The need for a physical model and the requirement that the model execute at extreme speeds, has held back the application of AS to practical problems. Two recent advances make it possible to consider the use of AS for practical intelligent sensors. First, advances in transducer technology make it possible to obtain previously unavailable data from which a model can be derived. For example, acoustic emissions (AE) can be fed into a Bayesian system identifier that enables the separation of a weak characterizing signal, such as the signature of pump cavitation precursors, from a strong masking signal, such as a pump vibration feature. The second advance is the development of extremely fast, but inexpensive, digital signal processing hardware on which it is possible to run an adaptive Bayesian-derived model faster than real-time. This paper reports the investigation of an AS using a model of cavitation based on hydrodynamic principles and Bayesian analysis of data from high-performance AE sensors.

  8. The effect of a non-steroidal anti-inflammatory drug on two important predictors for accidental falls: postural balance and manual reaction time. A randomized, controlled pilot study.

    NARCIS (Netherlands)

    Hegeman, J.; Nienhuis, B.; Bemt, B.J.F van den; Weerdesteijn, V.G.M.; Limbeek, J. van; Duysens, J.E.J.

    2011-01-01

    Accidental falls in older individuals are a major health and research topic. Increased reaction time and impaired postural balance have been determined as reliable predictors for those at risk of falling and are important functions of the central nervous system (CNS). An essential risk factor for fa

  9. 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.

  10. 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.

  11. The effect of a non-steroidal anti-inflammatory drug on two important predictors for accidental falls: postural balance and manual reaction time. A randomized, controlled pilot study.

    Science.gov (United States)

    Hegeman, Judith; Nienhuis, Bart; van den Bemt, Bart; Weerdesteyn, Vivian; van Limbeek, Jacques; Duysens, Jacques

    2011-04-01

    Accidental falls in older individuals are a major health and research topic. Increased reaction time and impaired postural balance have been determined as reliable predictors for those at risk of falling and are important functions of the central nervous system (CNS). An essential risk factor for falls is medication exposure. Amongst the medications related to accidental falls are the non-steroidal anti-inflammatory drugs (NSAIDs). About 1-10% of all users experience CNS side effects. These side effects, such as dizziness, headaches, drowsiness, mood alteration, and confusion, seem to be more common during treatment with indomethacin. Hence, it is possible that maintenance of (static) postural balance and swift reactions to stimuli are affected by exposure to NSAIDs, indomethacin in particular, consequently putting older individuals at a greater risk for accidental falls. The present study investigated the effect of a high indomethacin dose in healthy middle-aged individuals on two important predictors of falls: postural balance and reaction time. Twenty-two healthy middle-aged individuals (59.5 ± 4.7 years) participated in this double-blind, placebo-controlled, randomized crossover trial. Three measurements were conducted with a week interval each. A measurement consisted of postural balance as a single task and while concurrently performing a secondary cognitive task and reaction time tasks. For the first measurement indomethacin 75 mg (slow-release) or a visually identical placebo was randomly assigned. In total, five capsules were taken orally in the 2.5 days preceding assessment. The second measurement was without intervention, for the final one the first placebo group got indomethacin and vice versa. Repeated measures GLM revealed no significant differences between indomethacin, placebo, and baseline in any of the balance tasks. No differences in postural balance were found between the single and dual task conditions, or on the performance of the dual task

  12. Reduce torques and stick the landing: limb posture during landing in toads.

    Science.gov (United States)

    Azizi, Emanuel; Larson, Neil P; Abbott, Emily M; Danos, Nicole

    2014-10-15

    A controlled landing, where an animal does not crash or topple, requires enough stability to allow muscles to effectively dissipate mechanical energy. Toads (Rhinella marina) are exemplary models for understanding the mechanics and motor control of landing given their ability to land consistently during bouts of continuous hopping. Previous studies in anurans have shown that ground reaction forces (GRFs) during landing are significantly higher compared with takeoff and can potentially impart large torques about the center of mass (COM), destabilizing the body at impact. We predict that in order to minimize such torques, toads will align their COM with the GRF vector during the aerial phase in anticipation of impact. We combined high-speed videography and force-plate ergometry to quantify torques at the COM and relate the magnitude of torques to limb posture at impact. We show that modulation of hindlimb posture can shift the position of the COM by about 20% of snout-vent length. Rapid hindlimb flexion during the aerial phase of a hop moved the COM anteriorly and reduced torque by aligning the COM with the GRF vector. We found that the addition of extrinsic loads did not significantly alter landing behavior but did change the torques experienced at impact. We conclude that anticipatory hindlimb flexion during the aerial phase of a hop is a critical feature of a mechanically stable landing that allows toads to quickly string together multiple, continuous hops.

  13. Center of Pressure Displacement of Standing Posture during Rapid Movements Is Reorganised Due to Experimental Lower Extremity Muscle Pain.

    Directory of Open Access Journals (Sweden)

    Shinichiro Shiozawa

    Full Text Available Postural control during rapid movements may be impaired due to musculoskeletal pain. The purpose of this study was to investigate the effect of experimental knee-related muscle pain on the center of pressure (CoP displacement in a reaction time task condition.Nine healthy males performed two reaction time tasks (dominant side shoulder flexion and bilateral heel lift before, during, and after experimental pain induced in the dominant side vastus medialis or the tibialis anterior muscles by hypertonic saline injections. The CoP displacement was extracted from the ipsilateral and contralateral side by two force plates and the net CoP displacement was calculated.Compared with non-painful sessions, tibialis anterior muscle pain during the peak and peak-to-peak displacement for the CoP during anticipatory postural adjustments (APAs of the shoulder task reduced the peak-to-peak displacement of the net CoP in the medial-lateral direction (P<0.05. Tibialis anterior and vastus medialis muscle pain during shoulder flexion task reduced the anterior-posterior peak-to-peak displacement in the ipsilateral side (P<0.05.The central nervous system in healthy individuals was sufficiently robust in maintaining the APA characteristics during pain, although the displacement of net and ipsilateral CoP in the medial-lateral and anterior-posterior directions during unilateral fast shoulder movement was altered.

  14. Anticipatory Socialisation amongst Architects: A Qualitative Examination

    Science.gov (United States)

    Sang, Katherine; Ison, Stephen; Dainty, Andrew; Powell, Abigail

    2009-01-01

    Purpose: Those entering the architectural profession tend to be motivated by a desire to undertake creative design, although studies have revealed that many practicing architects feel they lack sufficient creative opportunities. Proponents of anticipatory socialisation argue that experiences prior to entering an occupation influence job…

  15. Personality traits and individual differences predict threat-induced changes in postural control.

    Science.gov (United States)

    Zaback, Martin; Cleworth, Taylor W; Carpenter, Mark G; Adkin, Allan L

    2015-04-01

    This study explored whether specific personality traits and individual differences could predict changes in postural control when presented with a height-induced postural threat. Eighty-two healthy young adults completed questionnaires to assess trait anxiety, trait movement reinvestment (conscious motor processing, movement self-consciousness), physical risk-taking, and previous experience with height-related activities. Tests of static (quiet standing) and anticipatory (rise to toes) postural control were completed under low and high postural threat conditions. Personality traits and individual differences significantly predicted height-induced changes in static, but not anticipatory postural control. Individuals less prone to taking physical risks were more likely to lean further away from the platform edge and sway at higher frequencies and smaller amplitudes. Individuals more prone to conscious motor processing were more likely to lean further away from the platform edge and sway at larger amplitudes. Individuals more self-conscious about their movement appearance were more likely to sway at smaller amplitudes. Evidence is also provided that relationships between physical risk-taking and changes in static postural control are mediated through changes in fear of falling and physiological arousal. Results from this study may have indirect implications for balance assessment and treatment; however, further work exploring these factors in patient populations is necessary.

  16. Social allostasis: anticipatory regulation of the internal milieu

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    Jay eSchulkin

    2011-01-01

    Full Text Available Social regulation of the internal milieu is a fundamental behavioral adaptation. Cephalic capabilityis reflected by anticipatory behaviors to serve systemic physiological regulation. Homeostaticregulation, a dominant perspective, reflects reactive responses; allostatic regulation, thephysiology of change, emphasizes longer-term anticipatory, and feedforward systems. Steroids,such as cortisol, and peptides such as corticotrophin releasing hormone are but one exampleof such anticipatory regulatory systems. The concept of allostasis is in part to take accountof anticipatory control amidst diverse forms of adaptation underlying this regulatory adaptationthat supports social contact and internal milieu.

  17. 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.

  18. Anticipatory Mechanisms in Evolutionary Living Systems

    Science.gov (United States)

    Dubois, Daniel M.; Holmberg, Stig C.

    2010-11-01

    This paper deals firstly with a revisiting of Darwin's theory of Natural Selection. Darwin in his book never uses the word "evolution", but shows a clear position about mutability of species. Darwin's Natural Selection was mainly inspired by the anticipatory Artificial Selection by humans in domestication, and the Malthus struggle for existence. Darwin showed that the struggle for existence leads to the preservation of the most divergent offspring of any one species. He cited several times the canon of "Natura non facit saltum". He spoke about the origin of life from some one primordial form, into which life was first breathed. Finally, Darwin made anticipation about the future researches in psychology. This paper cites the work of Ernst Mayr who was the first, after 90 years of an intense scientific debate, to present a new and stable Darwinian paradigm as the "Evolutionary Synthesis" in 1942. To explain what is life, the Living Systems Theory (LST) by J. G. Miller is presented. It is showed that the Autopoietic Systems Theory of Varela et al is also a fundamental component of living systems. In agreement with Darwin, the natural selection is a necessary condition for transformation of biological systems, but is not a sufficient condition. Thus, in this paper we conjecture that an anticipatory evolutionary mechanism exists with the genetic code that is a self-replicating and self-modifying anticipatory program. As demonstrated by Nobel laureate McClintock, evolution in genomes is programmed. The word "program" comes from "pro-gram" meaning to write before, by anticipation, and means a plan for the programming of a mechanism, or a sequence of coded instructions that can be inserted into a mechanism, or a sequence of coded instructions, as genes of behavioural responses, that is part of an organism. For example, cell death may be programmed by what is called the apoptosis. This definitively is a great breakthrough in our understanding of biological evolution. Hence

  19. Anticipatory Socialization and Male Catholic Adolescent Socio-Political Attitudes

    Science.gov (United States)

    O'Kane, James M.; And Others

    1977-01-01

    Merton and Kitts' thesis of anticipatory socialization is supported. The importance of the class of destination, as opposed to the class of origin is underscored implying that anticipatory socialization is a primary explanation for differential attitudes formulated before adolescents have undergone mobility or achieved status positions equal to…

  20. Anticipatory systems philosophical, mathematical and methodological foundations

    CERN Document Server

    Rosen, Robert

    1985-01-01

    The first detailed study of this most important class of systems which contain internal predictive models of themselves and/or of their environments and whose predictions are utilized for purposes of present control. This book develops the basic concept of a predictive model, and shows how it can be embedded into a system of feedforward control. Includes many examples and stresses analogies between wired-in anticipatory control and processes of learning and adaption, at both individual and social levels. Shows how the basic theory of such systems throws a new light both on analytic problems (u

  1. Corticospinal Excitability of Trunk Muscles during Different Postural Tasks.

    Science.gov (United States)

    Chiou, Shin-Yi; Gottardi, Sam E A; Hodges, Paul W; Strutton, Paul H

    2016-01-01

    Evidence suggests that the primary motor cortex (M1) is involved in both voluntary, goal-directed movements and in postural control. Trunk muscles are involved in both tasks, however, the extent to which M1 controls these muscles in trunk flexion/extension (voluntary movement) and in rapid shoulder flexion (postural control) remains unclear. The purpose of this study was to investigate this question by examining excitability of corticospinal inputs to trunk muscles during voluntary and postural tasks. Twenty healthy adults participated. Transcranial magnetic stimulation was delivered to the M1 to examine motor evoked potentials (MEPs) in the trunk muscles (erector spinae (ES) and rectus abdominis (RA)) during dynamic shoulder flexion (DSF), static shoulder flexion (SSF), and static trunk extension (STE). The level of background muscle activity in the ES muscles was matched across tasks. MEP amplitudes in ES were significantly larger in DSF than in SSF or in STE; however, this was not observed for RA. Further, there were no differences in levels of muscle activity in RA between tasks. Our findings reveal that corticospinal excitability of the ES muscles appears greater during dynamic anticipatory posture-related adjustments than during static tasks requiring postural (SSF) and goal-directed voluntary (STE) activity. These results suggest that task-oriented rehabilitation of trunk muscles should be considered for optimal transfer of therapeutic effect to function.

  2. Corticospinal Excitability of Trunk Muscles during Different Postural Tasks.

    Directory of Open Access Journals (Sweden)

    Shin-Yi Chiou

    Full Text Available Evidence suggests that the primary motor cortex (M1 is involved in both voluntary, goal-directed movements and in postural control. Trunk muscles are involved in both tasks, however, the extent to which M1 controls these muscles in trunk flexion/extension (voluntary movement and in rapid shoulder flexion (postural control remains unclear. The purpose of this study was to investigate this question by examining excitability of corticospinal inputs to trunk muscles during voluntary and postural tasks. Twenty healthy adults participated. Transcranial magnetic stimulation was delivered to the M1 to examine motor evoked potentials (MEPs in the trunk muscles (erector spinae (ES and rectus abdominis (RA during dynamic shoulder flexion (DSF, static shoulder flexion (SSF, and static trunk extension (STE. The level of background muscle activity in the ES muscles was matched across tasks. MEP amplitudes in ES were significantly larger in DSF than in SSF or in STE; however, this was not observed for RA. Further, there were no differences in levels of muscle activity in RA between tasks. Our findings reveal that corticospinal excitability of the ES muscles appears greater during dynamic anticipatory posture-related adjustments than during static tasks requiring postural (SSF and goal-directed voluntary (STE activity. These results suggest that task-oriented rehabilitation of trunk muscles should be considered for optimal transfer of therapeutic effect to function.

  3. [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.

  4. Visuomotor control of human adaptive locomotion: Understanding the anticipatory nature

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    Takahiro eHiguchi

    2013-05-01

    Full Text Available To maintain balance during locomotion, the central nervous system (CNS accommodates changes in the constraints of spatial environment (e.g., existence of an obstacle or changes in the surface properties. Locomotion while modifying the basic movement patterns in response to such constraints is referred to as adaptive locomotion. The most powerful means of ensuring balance during adaptive locomotion is to visually perceive the environmental properties at a distance and modify the movement patterns in an anticipatory manner to avoid perturbation altogether. For this reason, visuomotor control of adaptive locomotion is characterized, at least in part, by its anticipatory nature. The purpose of the present article is to review the relevant studies which revealed the anticipatory nature of the visuomotor control of adaptive locomotion. The anticipatory locomotor adjustments for stationary and changeable environment, as well as the spatio-temporal patterns of gaze behavior to support the anticipatory locomotor adjustments are described. Such description will clearly show that anticipatory locomotor adjustments are initiated when an object of interest (e.g., a goal or obstacle still exists in far space. This review also show that, as a prerequisite of anticipatory locomotor adjustments, environmental properties are accurately perceived from a distance in relation to individual’s action capabilities.

  5. Anticipatory nausea and vomiting due to chemotherapy.

    Science.gov (United States)

    Kamen, Charles; Tejani, Mohamedtaki A; Chandwani, Kavita; Janelsins, Michelle; Peoples, Anita R; Roscoe, Joseph A; Morrow, Gary R

    2014-01-05

    As a specific variation of chemotherapy-induced nausea and vomiting, anticipatory nausea and vomiting (ANV) appears particularly linked to psychological processes. The three predominant factors related to ANV are classical conditioning; demographic and treatment-related factors; and anxiety or negative expectancies. Laboratory models have provided some support for these underlying mechanisms for ANV. ANV may be treated with medical or pharmacological interventions, including benzodiazepines and other psychotropic medications. However, behavioral treatments, including systematic desensitization, remain first line options for addressing ANV. Some complementary treatment approaches have shown promise in reducing ANV symptoms. Additional research into these approaches is needed. This review will address the underlying models of ANV and provide a discussion of these various treatment options.

  6. From Anticipatory Corpse to Posthuman God.

    Science.gov (United States)

    Bishop, Jeffrey P

    2016-12-01

    The essays in this issue of JMP are devoted to critical engagement of my book, The Anticipatory Corpse The essays, for the most part, accept the main thrust of my critique of medicine. The main thrust of the criticism is whether the scope of the critique is too totalizing, and whether the proposed remedy is sufficient. I greatly appreciate these interventions because they allow me this occasion to respond and clarify, and to even further extend the argument of my book. In this response essay, I maintain that the regnant social imaginary of medicine is the regnant social imaginary of our time. It is grounded in a specific ontotheology: where ontology is a power ontology; where material is malleable to the open-ended organization of power and dependent only on working out the efficient mechanisms of its enactment; where ethically it is oriented only to the immanent telos of utility maximization in the short run, and ultimately to some posthuman future in the long run. This ontotheology originates in the anticipatory corpse and is ordered toward some god-like posthuman being. The entire ontotheology finds enactment through the political economy of neoliberalism. This social imaginary constantly works to insulate itself from other social imaginaries through the use of its institutional power, through marginalization, circumscription, or absorption. The modern social imaginary of neoliberal societies marginalizes and politically isolates other social imaginaries, or transforms them into something acceptable to the neoliberal imaginary. Yet, these other social imaginaries could influence the larger social imaginary in novel ways, sometimes through withdrawal and sometimes through challenges. These other practices-again, usually practices ordered according to different ontological and teleological purposes-might serve as a source of renewal and transformation, but only if the practitioners of these other social imaginaries understand the ontotheological powers that they

  7. Development of postural control during the first 18 months of life.

    Science.gov (United States)

    Hadders-Algra, Mijna

    2005-01-01

    The present paper reviews the development of postural adjustments during infancy. In the control of posture, two functional levels can be distinguished. The basic level deals with the generation of direction-specific adjustments, meaning that dorsal muscles are primarily activated when the body sways forward, whereas ventral muscles are primarily activated when the body sways backward. The second level is involved in adaptation of the direction-specific adjustments. Postural development starts with a repertoire of direction-specific adjustments suggesting that the basic level of control has an innate origin. At first, during the phase of primary variability, postural activity is largely variable and can be minimally adapted to environmental constraints. At 3 months, postural activity shows a transient period during which few postural muscles participate in postural activity. From 6 months onward, the phase of secondary variability starts, during which the second level of postural control becomes functionally active and infants develop the ability to adapt postural activity to the specifics of the situation. Initially, adaptation can be accomplished in a simple way only, but from 9-10 months onward, it can be performed by the subtle adaptation of the degree of muscle contraction. Around 13-14 months, anticipatory postural adjustments emerge. It is concluded that the development of postural adjustments is characterized by four periods of transition occurring at the ages of 3, 6, 9-10, and 13-14 months. The major transition occurs at 6 months, when infants move from the phase of non-adaptive, primary variability to the phase of adaptive, secondary variability.

  8. Development of Postural Control During the First 18 Months of Life

    Directory of Open Access Journals (Sweden)

    Mijna Hadders-Algra

    2005-01-01

    Full Text Available The present paper reviews the development of postural adjustments during infancy. In the control of posture, two functional levels can be distinguished. The basic level deals with the generation of direction-specific adjustments meaning that dorsal muscles are primarily activated when the body sways forward, whereas ventral muscles are primarily activated when the body sways backward. The second level is involved in adaptation of the direction-specific adjustments. Postural development starts with a repertoire of direction-specific adjustments suggesting that the basic level of control has an innate origin. At first, during the phase of primary variability, postural activity is largely variable and can be minimally adapted to environmental constraints. At 3 months, postural activity shows a transient period during which few postural muscles participate in postural activity. From 6 months onward, the phase of secondary variability starts, during which the second level of postural control becomes functionally active and infants develop the ability to adapt postural activity to the specifics of the situation. Initially, adaptation can be accomplished in a simple way only, but from 9–10 months onward, it can be performed by the subtle adaptation of the degree of muscle contraction. Around 13–14 months, anticipatory postural adjustments emerge. It is concluded that the development of postural adjustments is characterized by four periods of transition occurring at the ages of 3, 6, 9-10, and 13-14 months. The major transition occurs at 6 months, when infants move from the phase of non-adaptive, primary variability to the phase of adaptive, secondary variability.

  9. Predicting falls within the elderly community: comparison of postural sway, reaction time, the Berg balance scale and the Activities-specific Balance Confidence (ABC) scale for comparing fallers and non-fallers.

    Science.gov (United States)

    Lajoie, Y; Gallagher, S P

    2004-01-01

    Simple reaction time, the Berg balance scale, the Activities-specific Balance Confidence (ABC) scale and postural sway were studied in order to determine cut-off scores as well as develop a model used in the prevention of fallers within the elderly community. One hundred and twenty-five subjects, 45 fallers and 80 non-fallers were evaluated throughout the study and results indicated that non-fallers have significantly faster reaction times, have higher scores on the Berg balance scale and the ABC scale as well as sway at slower frequencies when compared to fallers. Furthermore, all risk factors were subsequently entered into a logistic regression analysis and results showed that reaction time, the total Berg score and the total ABC score contributed significantly to the prediction of falls with 89% sensitivity and 96% specificity. A second logistic regression was carried out with the same previous variables as well as all questions of the Berg and ABC scales. Results from the logistic analysis revealed that three variables were associated with fall status with 91% sensitivity and 97% specificity. Results from the following study would seem rather valuable as an assessment tool for health care professionals in the identification and monitoring of potential fallers within nursing homes and throughout the community.

  10. 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.

  11. Anticipatory planning in children with Autism Spectrum Disorder: An assessment of independent and joint action tasks

    Directory of Open Access Journals (Sweden)

    Sara Marie Scharoun

    2016-08-01

    Full Text Available Autism Spectrum Disorder (ASD is one of the most common neurodevelopmental disorders. Although not a diagnostic feature, motor impairments have been recently acknowledged as prevalent and significant, such that these children have difficulties planning, organizing and coordinating movements. This study aimed to further investigate anticipatory motor planning in children with ASD by means of assessing end- and beginning-state comfort, considering inconsistent reports of end-state comfort in independent action, and the study of beginning-state comfort being limited to one study with young adults. Five- to 11-year-old children with ASD, and chronologically age- and sex matched typically-developing children picked-up a glass and (1 poured a cup of water; and (2 passed it to the researcher to pour a cup of water. End-state comfort was deemed evident if participants grasped the glass thumb-down followed by a 180° rotation; therefore ending with a thumb-up posture. Beginning-state comfort was deemed evident if participants passed the glass to the researcher oriented upright. Findings revealed less end-state comfort in children with ASD, attributed to motor planning deficits. Beginning-state comfort did not differ, ascribed to the habitual nature of the task; therefore reflecting a stimulus-driven response as opposed to an action which reflects anticipatory planning. Findings support difficulties with motor planning and control for children with ASD in an independent task. However, when acting with a familiar object in joint action, behaviour does not differ, likely indicative of a habitual, stimulus-driven response.

  12. Anticipatory Planning in Children with Autism Spectrum Disorder: An Assessment of Independent and Joint Action Tasks.

    Science.gov (United States)

    Scharoun, Sara M; Bryden, Pamela J

    2016-01-01

    Autism Spectrum Disorder (ASD) is one of the most common neurodevelopmental disorders. Although not a diagnostic feature, motor impairments have been recently acknowledged as prevalent and significant, such that these children have difficulties planning, organizing and coordinating movements. This study aimed to further investigate anticipatory motor planning in children with ASD by means of assessing end- and beginning-state comfort, considering inconsistent reports of end-state comfort in independent action, and the study of beginning-state comfort being limited to one study with young adults. Five- to eleven-year-old children with ASD, and chronologically age- and sex-matched typically-developing children picked-up a glass and: (1) poured a cup of water; and (2) passed it to the researcher to pour a cup of water. End-state comfort was deemed evident if participants grasped the glass thumb-down followed by a 180° rotation; therefore ending with a thumb-up posture. Beginning-state comfort was deemed evident if participants passed the glass to the researcher oriented upright. Findings revealed less end-state comfort in children with ASD, attributed to motor planning deficits. Beginning-state comfort did not differ, ascribed to the habitual nature of the task; therefore reflecting a stimulus-driven response as opposed to an action which reflects anticipatory planning. The findings support difficulties with motor planning and control for children with ASD in an independent task. However, when acting with a familiar object in joint action, behavior does not differ, likely indicative of a habitual, stimulus-driven response.

  13. 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…

  14. Diurnally entrained anticipatory behavior in archaea.

    Directory of Open Access Journals (Sweden)

    Kenia Whitehead

    Full Text Available By sensing changes in one or few environmental factors biological systems can anticipate future changes in multiple factors over a wide range of time scales (daily to seasonal. This anticipatory behavior is important to the fitness of diverse species, and in context of the diurnal cycle it is overall typical of eukaryotes and some photoautotrophic bacteria but is yet to be observed in archaea. Here, we report the first observation of light-dark (LD-entrained diurnal oscillatory transcription in up to 12% of all genes of a halophilic archaeon Halobacterium salinarum NRC-1. Significantly, the diurnally entrained transcription was observed under constant darkness after removal of the LD stimulus (free-running rhythms. The memory of diurnal entrainment was also associated with the synchronization of oxic and anoxic physiologies to the LD cycle. Our results suggest that under nutrient limited conditions halophilic archaea take advantage of the causal influence of sunlight (via temperature on O(2 diffusivity in a closed hypersaline environment to streamline their physiology and operate oxically during nighttime and anoxically during daytime.

  15. Typical and atypical development of reaching and postural control in infancy.

    Science.gov (United States)

    Hadders-Algra, Mijna

    2013-11-01

    Successful reaching requires postural control, either by active regulation or by postural support. The present paper reviews literature on typical and atypical development of reaching and postural control during infancy. Typically, reaching movements end in grasping around 4 months of age. Initially, reaches are characterized by large variation, including many trajectory corrections. During the first year, the movements get increasingly straight and smooth. Reaching in low-risk preterm infants is initially characterized by advanced development, but minor impairments may emerge in the second half of infancy. In high-risk preterm infants, development of reaching is characterized by delay and non-optimal reaching performance. Typical development of postural adjustments is characterized by variation and an increasing ability to adapt the variable repertoire to the specifics of the situation. The latter is facilitated by an increasing role of anticipatory mechanisms in the second half of infancy. Atypically developing infants may have a reduced repertoire and usually have difficulties in adapting postural adjustments. In infancy, most reaching movements are performed during sitting. The postural challenge of sitting may interfere in particular with the development of reaching in atypically developing infants. The practical implications of this suggestion are discussed.

  16. 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.

  17. Trial-to-trial adaptation in control of arm reaching and standing posture.

    Science.gov (United States)

    Pienciak-Siewert, Alison; Horan, Dylan P; Ahmed, Alaa A

    2016-12-01

    Classical theories of motor learning hypothesize that adaptation is driven by sensorimotor error; this is supported by studies of arm and eye movements that have shown that trial-to-trial adaptation increases with error. Studies of postural control have shown that anticipatory postural adjustments increase with the magnitude of a perturbation. However, differences in adaptation have been observed between the two modalities, possibly due to either the inherent instability or sensory uncertainty in standing posture. Therefore, we hypothesized that trial-to-trial adaptation in posture should be driven by error, similar to what is observed in arm reaching, but the nature of the relationship between error and adaptation may differ. Here we investigated trial-to-trial adaptation of arm reaching and postural control concurrently; subjects made reaching movements in a novel dynamic environment of varying strengths, while standing and holding the handle of a force-generating robotic arm. We found that error and adaptation increased with perturbation strength in both arm and posture. Furthermore, in both modalities, adaptation showed a significant correlation with error magnitude. Our results indicate that adaptation scales proportionally with error in the arm and near proportionally in posture. In posture only, adaptation was not sensitive to small error sizes, which were similar in size to errors experienced in unperturbed baseline movements due to inherent variability. This finding may be explained as an effect of uncertainty about the source of small errors. Our findings suggest that in rehabilitation, postural error size should be considered relative to the magnitude of inherent movement variability.

  18. 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 ...

  19. The Differential Outcomes Effect in Pigeons (Columba livia: Is It Truly Anticipatory?

    Directory of Open Access Journals (Sweden)

    Marijn Kouwenhoven

    Full Text Available We used delay-interval interference to investigate the nature of the differential outcomes effect (DOE in pigeons. Birds were trained on a delayed matching-to-sample (DMS task under either common outcome or differential outcome conditions, and then presented with visual interference during the delay period. Consistent with previous literature, the common outcomes birds were slower to learn the DMS task than the differential outcomes birds. The common outcome birds were also more impaired by the visual interference than the differential outcomes birds. Our findings are consistent with the view that the birds trained with common outcomes were likely remembering the sample stimulus during the delay period, and hence were disrupted by the visual interference, whereas the birds trained with differential outcomes were likely relying on the different emotional reactions elicited by the different outcomes to guide their choice behaviour, and hence were less affected by the visual interference. Our findings suggest that the DOE is not truly evidence of anticipatory mediation of short-term retention in pigeons, but rather emotionally driven decision making, which is not truly anticipatory in nature.

  20. The Differential Outcomes Effect in Pigeons (Columba livia): Is It Truly Anticipatory?

    Science.gov (United States)

    Kouwenhoven, Marijn; Colombo, Michael

    2016-01-01

    We used delay-interval interference to investigate the nature of the differential outcomes effect (DOE) in pigeons. Birds were trained on a delayed matching-to-sample (DMS) task under either common outcome or differential outcome conditions, and then presented with visual interference during the delay period. Consistent with previous literature, the common outcomes birds were slower to learn the DMS task than the differential outcomes birds. The common outcome birds were also more impaired by the visual interference than the differential outcomes birds. Our findings are consistent with the view that the birds trained with common outcomes were likely remembering the sample stimulus during the delay period, and hence were disrupted by the visual interference, whereas the birds trained with differential outcomes were likely relying on the different emotional reactions elicited by the different outcomes to guide their choice behaviour, and hence were less affected by the visual interference. Our findings suggest that the DOE is not truly evidence of anticipatory mediation of short-term retention in pigeons, but rather emotionally driven decision making, which is not truly anticipatory in nature.

  1. Differentiating anticipatory from reactive cortisol responses to psychosocial stress

    NARCIS (Netherlands)

    Engert, V.; Efanov, S.I.; Duchesne, A.; Vogel, S.; Corbo, V.; Pruessner, J.C.

    2013-01-01

    Most psychosocial stress studies assess the overall cortisol response without further identifying the temporal dynamics within hormone levels. It has been shown, however, that the amplitude of anticipatory cortisol stress levels has a unique predictive value for psychological health. So far, no "bes

  2. Anticipatory Enrollment Management: Another Level of Enrollment Management

    Science.gov (United States)

    Dennis, Marguerite J.

    2012-01-01

    Building on the principles of Enrollment Management (EM) and Strategic Enrollment Management (SEM), Anticipatory Enrollment Management (AEM) offers another level of managing enrollment: anticipating future enrollment. AEM is grounded in the basic principles of Customer Relationship Management (CRM) and includes strategic out-reach to parents and…

  3. Corruption in Education Sector Development: A Suggestion for Anticipatory Strategy.

    Science.gov (United States)

    Tanaka, Shinichiro

    2001-01-01

    Proposes an anticipatory strategy that will help protect education sector development from corruption. The strategy, which may exist as a "hidden agenda" within a project, focuses on diagnosing rather than redressing a system thought to be corrupt, adopting prevention rather than punishment, informal rather than formal approaches, and…

  4. 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

  5. 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.

  6. STEADFAST: Psychotherapeutic Intervention Improves Postural Strategy of Somatoform Vertigo and Dizziness

    Directory of Open Access Journals (Sweden)

    Christoph Best

    2015-01-01

    Full Text Available Patients with somatoform vertigo and dizziness (SVD disorders often report instability of stance or gait and fear of falling. Posturographic measurements indeed indicated a pathological postural strategy. Our goal was to evaluate the effectiveness of a psychotherapeutic and psychoeducational short-term intervention (PTI using static posturography and psychometric examination. Seventeen SVD patients took part in the study. The effects of PTI on SVD were evaluated with quantitative static posturography. As primary endpoint a quotient characterizing the relation between horizontal and vertical sway was calculated (QH/V, reflecting the individual postural strategy. Results of static posturography were compared to those of age- and gender-matched healthy volunteers (n=28; baseline measurements were compared to results after PTI. The secondary endpoint was the participation-limiting consequences of SVD as measured by the Vertigo Handicap Questionnaire (VHQ. Compared to the healthy volunteers, the patients with SVD showed a postural strategy characterized by stiffening-up that resulted in a significantly reduced body sway quotient before PTI (patients: QH/V=0.31 versus controls: QH/V=0.38; p=0.022. After PTI the postural behavior normalized, and psychological distress was reduced. PTI therefore appears to modify pathological balance behaviour. The postural strategy of patients with SVD possibly results from anxious anticipatory cocontraction of the antigravity muscles.

  7. STEADFAST: Psychotherapeutic Intervention Improves Postural Strategy of Somatoform Vertigo and Dizziness.

    Science.gov (United States)

    Best, Christoph; Tschan, Regine; Stieber, Nikola; Beutel, Manfred E; Eckhardt-Henn, Annegret; Dieterich, Marianne

    2015-01-01

    Patients with somatoform vertigo and dizziness (SVD) disorders often report instability of stance or gait and fear of falling. Posturographic measurements indeed indicated a pathological postural strategy. Our goal was to evaluate the effectiveness of a psychotherapeutic and psychoeducational short-term intervention (PTI) using static posturography and psychometric examination. Seventeen SVD patients took part in the study. The effects of PTI on SVD were evaluated with quantitative static posturography. As primary endpoint a quotient characterizing the relation between horizontal and vertical sway was calculated (Q H/V ), reflecting the individual postural strategy. Results of static posturography were compared to those of age- and gender-matched healthy volunteers (n = 28); baseline measurements were compared to results after PTI. The secondary endpoint was the participation-limiting consequences of SVD as measured by the Vertigo Handicap Questionnaire (VHQ). Compared to the healthy volunteers, the patients with SVD showed a postural strategy characterized by stiffening-up that resulted in a significantly reduced body sway quotient before PTI (patients: Q H/V = 0.31 versus controls: Q H/V = 0.38; p = 0.022). After PTI the postural behavior normalized, and psychological distress was reduced. PTI therefore appears to modify pathological balance behaviour. The postural strategy of patients with SVD possibly results from anxious anticipatory cocontraction of the antigravity muscles.

  8. 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

  9. 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....

  10. 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

  11. Postural stability and physical performance in social dancers.

    Science.gov (United States)

    Zhang, Jian-Guo; Ishikawa-Takata, Kazuko; Yamazaki, Hideo; Morita, Takae; Ohta, Toshiki

    2008-05-01

    This cross-sectional study examined the benefits of social dancing on postural stability and physical performance in dancers aged 50 years or more. Walking speed, lower limb reaction time and low back flexibility were measured in 202 social dancers and 202 community-dwelling comparison subjects aged 50-87 years. The results showed that dancers who were older than 60 years had better postural stability and faster leg reaction times, whilst dancers aged 50-59 showed only better flexibility, when compared with the controls. Male dancers had greater low back flexibility and leg reaction time compared to controls. In contrast, female dancers had superior performance only for leg reaction time when compared with controls. The results indicate that social dancing is associated with enhanced postural stability and physical performance in older adults.

  12. 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.

  13. Action prediction based on anticipatory brain potentials during simulated driving

    Science.gov (United States)

    Khaliliardali, Zahra; Chavarriaga, Ricardo; Gheorghe, Lucian Andrei; Millán, José del R.

    2015-12-01

    Objective. The ability of an automobile to infer the driver’s upcoming actions directly from neural signals could enrich the interaction of the car with its driver. Intelligent vehicles fitted with an on-board brain-computer interface able to decode the driver’s intentions can use this information to improve the driving experience. In this study we investigate the neural signatures of anticipation of specific actions, namely braking and accelerating. Approach. We investigated anticipatory slow cortical potentials in electroencephalogram recorded from 18 healthy participants in a driving simulator using a variant of the contingent negative variation (CNV) paradigm with Go and No-go conditions: count-down numbers followed by ‘Start’/‘Stop’ cue. We report decoding performance before the action onset using a quadratic discriminant analysis classifier based on temporal features. Main results. (i) Despite the visual and driving related cognitive distractions, we show the presence of anticipatory event related potentials locked to the stimuli onset similar to the widely reported CNV signal (with an average peak value of -8 μV at electrode Cz). (ii) We demonstrate the discrimination between cases requiring to perform an action upon imperative subsequent stimulus (Go condition, e.g. a ‘Red’ traffic light) versus events that do not require such action (No-go condition; e.g. a ‘Yellow’ light); with an average single trial classification performance of 0.83 ± 0.13 for braking and 0.79 ± 0.12 for accelerating (area under the curve). (iii) We show that the centro-medial anticipatory potentials are observed as early as 320 ± 200 ms before the action with a detection rate of 0.77 ± 0.12 in offline analysis. Significance. We show for the first time the feasibility of predicting the driver’s intention through decoding anticipatory related potentials during simulated car driving with high recognition rates.

  14. Trait Anticipatory Pleasure Predicts Effort Expenditure for Reward.

    Directory of Open Access Journals (Sweden)

    Joachim T Geaney

    Full Text Available Research in motivation and emotion has been increasingly influenced by the perspective that processes underpinning the motivated approach of rewarding goals are distinct from those underpinning enjoyment during reward consummation. This distinction recently inspired the construction of the Temporal Experience of Pleasure Scale (TEPS, a self-report measure that distinguishes trait anticipatory pleasure (pre-reward feelings of desire from consummatory pleasure (feelings of enjoyment and gratification upon reward attainment. In a university community sample (N = 97, we examined the TEPS subscales as predictors of (1 the willingness to expend effort for monetary rewards, and (2 affective responses to a pleasant mood induction procedure. Results showed that both anticipatory pleasure and a well-known trait measure of reward motivation predicted effort-expenditure for rewards when the probability of being rewarded was relatively low. Against expectations, consummatory pleasure was unrelated to induced pleasant affect. Taken together, our findings provide support for the validity of the TEPS anticipatory pleasure scale, but not the consummatory pleasure scale.

  15. Emotion dysregulation, anticipatory cortisol, and substance use in urban adolescents.

    Science.gov (United States)

    Kliewer, Wendy; Riley, Tennisha; Zaharakis, Nikola; Borre, Alicia; Drazdowski, Tess K; Jäggi, Lena

    2016-09-01

    Anticipatory cortisol is associated with risk for substance use in adolescents. The present study extended prior literature by testing a model linking family emotional climate, emotion dysregulation, anticipatory cortisol, and substance use. Participants were 229 adolescents (M = 11.94 years, SD = 1.55; 41% male; 92% African American) enrolled in a 4-wave study of stressors, physiological stress responses, and substance use. Caregivers completed measures of family emotional climate at baseline and adolescents' emotion dysregulation one and two years later; adolescents reported on their substance use at baseline and three years later at Wave 4. Adolescents completed a stress task at Wave 4; saliva samples taken immediately prior to the task were analyzed for cortisol. Longitudinal path models revealed that a negative emotional climate at home was associated with elevated emotion dysregulation at subsequent waves for all youth. Emotional dysregulation was prospectively associated with blunted anticipatory cortisol, which in turn was associated with elevated substance use, controlling for baseline substance use and age. However, these associations only were observed for females. This study suggests that helping girls in particular manage their emotional responses to stress more effectively may impact their physiological responses and reduce risk for substance use.

  16. Anticipatory precrash restraint sensor feasibility study: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.; Dress, W.B.

    1995-08-01

    This report explores feasibility of an anticipatory precrash restraint sensor. The foundation principle is the anticipation mechanism found at a primitive level of biological intelligence and originally formalized by the mathematical biologist Robert Rosen. A system based on formal anticipatory principles should significantly outperform conventional technologies. It offers the prospect of high payoff in prevention of death and injury. Sensors and processes are available to provide a good, fast, and inexpensive description of the present dynamical state of the vehicle to the embedded system model in the anticipation engine. The experimental part of this study found that inexpensive radar in a real-world setting does return useful data on target dynamics. The data produced by a radar system can be converted to target dynamical information by good, fast and inexpensive signal-processing techniques. Not only is the anticipatory sensor feasible, but further development under the sponsorship of the National Highway Traffic Safety Administration is necessary and desirable. There are a number of possible lines of follow-on investigation. The level of effort and expected benefits of various alternatives are discussed.

  17. Contraction of the human diaphragm during rapid postural adjustments.

    Science.gov (United States)

    Hodges, P W; Butler, J E; McKenzie, D K; Gandevia, S C

    1997-12-01

    1. The response of the diaphragm to the postural perturbation produced by rapid flexion of the shoulder to a visual stimulus was evaluated in standing subjects. Gastric, oesophageal and transdiaphragmatic pressures were measured together with intramuscular and oesophageal recordings of electromyographic activity (EMG) in the diaphragm. To assess the mechanics of contraction of the diaphragm, dynamic changes in the length of the diaphragm were measured with ultrasonography. 2. With rapid flexion of the shoulder in response to a visual stimulus, EMG activity in the costal and crural diaphragm occurred about 20 ms prior to the onset of deltoid EMG. This anticipatory contraction occurred irrespective of the phase of respiration in which arm movement began. The onset of diaphragm EMG coincided with that of transversus abdominis. 3. Gastric and transdiaphragmatic pressures increased in association with the rapid arm flexion by 13.8 +/- 1.9 (mean +/- S.E.M.) and 13.5 +/- 1.8 cmH2O, respectively. The increases occurred 49 +/- 4 ms after the onset of diaphragm EMG, but preceded the onset of movement of the limb by 63 +/- 7 ms. 4. Ultrasonographic measurements revealed that the costal diaphragm shortened and then lengthened progressively during the increase in transdiaphragmatic pressure. 5. This study provides definitive evidence that the human diaphragm is involved in the control of postural stability during sudden voluntary movement of the limbs.

  18. Contraction of the human diaphragm during rapid postural adjustments.

    Science.gov (United States)

    Hodges, P W; Butler, J E; McKenzie, D K; Gandevia, S C

    1997-01-01

    1. The response of the diaphragm to the postural perturbation produced by rapid flexion of the shoulder to a visual stimulus was evaluated in standing subjects. Gastric, oesophageal and transdiaphragmatic pressures were measured together with intramuscular and oesophageal recordings of electromyographic activity (EMG) in the diaphragm. To assess the mechanics of contraction of the diaphragm, dynamic changes in the length of the diaphragm were measured with ultrasonography. 2. With rapid flexion of the shoulder in response to a visual stimulus, EMG activity in the costal and crural diaphragm occurred about 20 ms prior to the onset of deltoid EMG. This anticipatory contraction occurred irrespective of the phase of respiration in which arm movement began. The onset of diaphragm EMG coincided with that of transversus abdominis. 3. Gastric and transdiaphragmatic pressures increased in association with the rapid arm flexion by 13.8 +/- 1.9 (mean +/- S.E.M.) and 13.5 +/- 1.8 cmH2O, respectively. The increases occurred 49 +/- 4 ms after the onset of diaphragm EMG, but preceded the onset of movement of the limb by 63 +/- 7 ms. 4. Ultrasonographic measurements revealed that the costal diaphragm shortened and then lengthened progressively during the increase in transdiaphragmatic pressure. 5. This study provides definitive evidence that the human diaphragm is involved in the control of postural stability during sudden voluntary movement of the limbs. Images Figure 1 PMID:9423192

  19. Caffeine improves anticipatory processes in task switching

    NARCIS (Netherlands)

    Tieges, Zoe; Snel, Jan; Kok, Albert; Wijnen, Jasper G.; Lorist, Monicque M.; Ridderinkhof, K. Richard

    2006-01-01

    We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e

  20. Reactively and Anticipatory Behaving Agents for Artificial Life Simulations

    Science.gov (United States)

    Kohout, Karel; Nahodil, Pavel

    2010-11-01

    Reactive behavior is still considered and the exact opposite for the anticipatory one. Despite the advances on the field of anticipation there are little thoughts on relation with the reactive behavior, the similarities and where the boundary is. In this article we will present our viewpoint and we will try to show that reactive and anticipatory behavior can be combined. This is the basic ground of our unified theory for anticipatory behavior architecture. We still miss such compact theory, which would integrate multiple aspects of anticipation. My multi-level anticipatory behavior approach is based on the current understanding of anticipation from both the artificial intelligence and biology point of view. As part of the explanation we will also elaborate on the topic of weak and strong artificial life. Anticipation is not matter of a single mechanism in a living organism. It was noted already that it happens on many different levels even in the very simple creatures. What we consider to be important for our work and what is our original though is that it happens even without voluntary control. We believe that this is novelty though for the anticipation theory. Naturally research of anticipation was in the beginning of this decade focused on the anticipatory principles bringing advances on the field itself. This allowed us to build on those, look at them from higher perspective, and use not one but multiple levels of anticipation in a creature design. This presents second original though and that is composition of the agent architecture that has anticipation built in almost every function. In this article we will focus only on first two levels within the 8-factor anticipation framework. We will introduce them as defined categories of anticipation and describe them from theory and implementation algorithm point of view. We will also present an experiment conducted, however this experiment serves more as explanatory example. These first two levels may seem trivial

  1. 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...

  2. Control of vertical posture while elevating one foot to avoid a real or virtual obstacle.

    Science.gov (United States)

    Ida, Hirofumi; Mohapatra, Sambit; Aruin, Alexander

    2017-03-07

    The purpose of this study is to investigate the control of vertical posture during obstacle avoidance in a real versus a virtual reality (VR) environment. Ten healthy participants stood upright and lifted one leg to avoid colliding with a real obstacle sliding on the floor toward a participant and with its virtual image. Virtual obstacles were delivered by a head mounted display (HMD) or a 3D projector. The acceleration of the foot, center of pressure, and electrical activity of the leg and trunk muscles were measured and analyzed during the time intervals typical for early postural adjustments (EPAs), anticipatory postural adjustments (APAs), and compensatory postural adjustments (CPAs). The results showed that the peak acceleration of foot elevation in the HMD condition decreased significantly when compared with that of the real and 3D projector conditions. Reduced activity of the leg and trunk muscles was seen when dealing with virtual obstacles (HMD and 3D projector) as compared with that seen when dealing with real obstacles. These effects were more pronounced during APAs and CPAs. The onsets of muscle activities in the supporting limb were seen during EPAs and APAs. The observed modulation of muscle activity and altered patterns of movement seen while avoiding a virtual obstacle should be considered when designing virtual rehabilitation protocols.

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

    Science.gov (United States)

    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.

  4. Predicting the unpredictable: Critical analysis and practical implications of predictive anticipatory activity

    Directory of Open Access Journals (Sweden)

    Julia eMossbridge

    2014-03-01

    Full Text Available A recent meta-analysis of experiments from seven independent laboratories (n=26 published since 1978 indicates that the human body can apparently detect randomly delivered stimuli occurring 1-10 seconds in the future (Mossbridge, Tressoldi, & Utts, 2012. The key observation in these studies is that human physiology appears to be able to distinguish between unpredictable dichotomous future stimuli, such as emotional vs. neutral images or sound vs. silence. This phenomenon has been called presentiment (as in feeling the future. In this paper we call it predictive anticipatory activity or PAA. The phenomenon is predictive because it can distinguish between upcoming stimuli; it is anticipatory because the physiological changes occur before a future event; and it is an activity because it involves changes in the cardiopulmonary, skin, and/or nervous systems. PAA is an unconscious phenomenon that seems to be a time-reversed reflection of the usual physiological response to a stimulus. It appears to resemble precognition (consciously knowing something is going to happen before it does, but PAA specifically refers to unconscious physiological reactions as opposed to conscious premonitions. Though it is possible that PAA underlies the conscious experience of precognition, experiments testing this idea have not produced clear results. The first part of this paper reviews the evidence for PAA and examines the two most difficult challenges for obtaining valid evidence for it: expectation bias and multiple analyses. The second part speculates on possible mechanisms and the theoretical implications of PAA for understanding physiology and consciousness. The third part examines potential practical applications.

  5. Mu-opioid receptor knockout mice show diminished food-anticipatory activity

    NARCIS (Netherlands)

    Kas, Martien J H; van den Bos, Ruud; Baars, Annemarie M; Lubbers, Marianne; Lesscher, Heidi M B; Hillebrand, Jacquelien J G; Schuller, Alwin G; Pintar, John E; Spruijt, Berry M

    2004-01-01

    We have previously suggested that during or prior to activation of anticipatory behaviour to a coming reward, mu-opioid receptors are activated. To test this hypothesis schedule induced food-anticipatory activity in mu-opioid receptor knockout mice was measured using running wheels. We hypothesized

  6. Test Plan of the Anticipatory Wirelss Sensor Network for the Critical Energy Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Rentel

    2006-09-01

    The test plan for the performance of the Anticipatory Wireless Sensor Network (A-WSN) is presented. The results of the test campaigns will be obtained after actual measurements are taken in the field with the Wireless Sensor Network developed by The Innovation Center-Eaton Corp., and the Anticipatory algorithms developed by ORNL.

  7. Effect of Experimentally-Induced Trunk Muscular Tensions on the Sit-to-Stand Task Performance and Associated Postural Adjustments

    OpenAIRE

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

    It has been shown that increased muscular activity along the trunk is likely to impair body balance, but there is little knowledge about its consequences on more dynamic tasks. The purpose of this study was to determine the effect of unilateral and bilateral increases of muscular tension along the trunk on the sit-to-stand task (STS) performance and associated anticipatory postural adjustments (APAs). Twelve healthy females (23 ± 3 years, 163 ± 0.06 cm, 56 ± 9 kg), free of any neurological or...

  8. Effects of dual tasking on the postural performance of people with and without multiple sclerosis: a pilot study.

    Science.gov (United States)

    Jacobs, Jesse V; Kasser, Susan L

    2012-06-01

    People with multiple sclerosis (MS) exhibit both cognitive and postural impairments. This study examined the effects of MS and of dual tasking on postural performance, and explored associations among dual-task postural performance, cognitive capacity, fear of falling, and fatigue. Thirteen subjects with MS (Expanded Disability Status Scale: 0-4.5) and 13 matched subjects without MS performed three tasks of standing postural control, with and without dual tasking amid an auditory Stroop task: (1) step initiation, (2) forward leaning to the limits of stability, and (3) postural responses to rotations of the support surface. Two-factor general linear models were used to evaluate differences between the groups (with or without MS) and two conditions (single or dual tasking) for each postural task. During step initiation, dual tasking significantly delayed the onset of the anticipatory postural adjustment (APA) more for the subjects with MS than for those without MS, and step lengths increased for the subjects with MS but decreased for those without MS. No other significant group-by-condition interactions were evident on the recorded variables of stepping, leaning, postural responses, or Stroop-response accuracies and latencies. The scores for the subjects with MS on the Modified Fatigue Impact Scale significantly associated with the change between single-task to dual-task conditions in APA onset and foot-lift onset during step initiation as well as in lean position variability and lean onset times during forward leaning. The results suggest dual-task effects were more evident during step initiation and are associated with levels of fatigue for subjects with MS.

  9. 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

  10. Anticipatory Learning for Climate Change Adaptation and Resilience

    Directory of Open Access Journals (Sweden)

    Petra Tschakert

    2010-06-01

    Full Text Available This paper is a methodological contribution to emerging debates on the role of learning, particularly forward-looking (anticipatory learning, as a key element for adaptation and resilience in the context of climate change. First, we describe two major challenges: understanding adaptation as a process and recognizing the inadequacy of existing learning tools, with a specific focus on high poverty contexts and complex livelihood-vulnerability risks. Then, the article examines learning processes from a dynamic systems perspective, comparing theoretical aspects and conceptual advances in resilience thinking and action research/learning (AR/AL. Particular attention is paid to learning loops (cycles, critical reflection, spaces for learning, and power. Finally, we outline a methodological framework to facilitate iterative learning processes and adaptive decision making in practice. We stress memory, monitoring of key drivers of change, scenario planning, and measuring anticipatory capacity as crucial ingredients. Our aim is to identify opportunities and obstacles for forward-looking learning processes at the intersection of climatic uncertainty and development challenges in Africa, with the overarching objective to enhance adaptation and resilient livelihood pathways, rather than learning by shock.

  11. Individual differences in impulsivity predict anticipatory eye movements.

    Directory of Open Access Journals (Sweden)

    Laetitia Cirilli

    Full Text Available Impulsivity is the tendency to act without forethought. It is a personality trait commonly used in the diagnosis of many psychiatric diseases. In clinical practice, impulsivity is estimated using written questionnaires. However, answers to questions might be subject to personal biases and misinterpretations. In order to alleviate this problem, eye movements could be used to study differences in decision processes related to impulsivity. Therefore, we investigated correlations between impulsivity scores obtained with a questionnaire in healthy subjects and characteristics of their anticipatory eye movements in a simple smooth pursuit task. Healthy subjects were asked to answer the UPPS questionnaire (Urgency Premeditation Perseverance and Sensation seeking Impulsive Behavior scale, which distinguishes four independent dimensions of impulsivity: Urgency, lack of Premeditation, lack of Perseverance, and Sensation seeking. The same subjects took part in an oculomotor task that consisted of pursuing a target that moved in a predictable direction. This task reliably evoked anticipatory saccades and smooth eye movements. We found that eye movement characteristics such as latency and velocity were significantly correlated with UPPS scores. The specific correlations between distinct UPPS factors and oculomotor anticipation parameters support the validity of the UPPS construct and corroborate neurobiological explanations for impulsivity. We suggest that the oculomotor approach of impulsivity put forth in the present study could help bridge the gap between psychiatry and physiology.

  12. Developing Anticipatory Life Cycle Assessment Tools to Support Responsible Innovation

    Science.gov (United States)

    Wender, Benjamin

    Several prominent research strategy organizations recommend applying life cycle assessment (LCA) early in the development of emerging technologies. For example, the US Environmental Protection Agency, the National Research Council, the Department of Energy, and the National Nanotechnology Initiative identify the potential for LCA to inform research and development (R&D) of photovoltaics and products containing engineered nanomaterials (ENMs). In this capacity, application of LCA to emerging technologies may contribute to the growing movement for responsible research and innovation (RRI). However, existing LCA practices are largely retrospective and ill-suited to support the objectives of RRI. For example, barriers related to data availability, rapid technology change, and isolation of environmental from technical research inhibit application of LCA to developing technologies. This dissertation focuses on development of anticipatory LCA tools that incorporate elements of technology forecasting, provide robust explorations of uncertainty, and engage diverse innovation actors in overcoming retrospective approaches to environmental assessment and improvement of emerging technologies. Chapter one contextualizes current LCA practices within the growing literature articulating RRI and identifies the optimal place in the stage gate innovation model to apply LCA. Chapter one concludes with a call to develop anticipatory LCA---building on the theory of anticipatory governance---as a series of methodological improvements that seek to align LCA practices with the objectives of RRI. Chapter two provides a framework for anticipatory LCA, identifies where research from multiple disciplines informs LCA practice, and builds off the recommendations presented in the preceding chapter. Chapter two focuses on crystalline and thin film photovoltaics (PV) to illustrate the novel framework, in part because PV is an environmentally motivated technology undergoing extensive R&D efforts and

  13. Attention Demand and Postural Control in Children with Hearing Deficit

    Science.gov (United States)

    Derlich, Malgorzata; Krecisz, Krzysztof; Kuczynski, Michal

    2011-01-01

    To elucidate the mechanisms responsible for deteriorated postural control in children with hearing deficit (CwHD), we measured center-of-pressure (COP) variability, mean velocity and entropy in bipedal quiet stance (feet together) with or without the concurrent cognitive task (reaction to visual stimulus) on hard or foam surface in 29 CwHD and a…

  14. Gravitational Effects upon Locomotion Posture

    Science.gov (United States)

    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.

  15. 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.

  16. 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.

  17. 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.

  18. A Telerehabilitation Program Improves Postural Control in Multiple Sclerosis Patients: A Spanish Preliminary Study

    Directory of Open Access Journals (Sweden)

    Rosa Ortiz-Gutiérrez

    2013-10-01

    Full Text Available Postural control disorders are among the most frequent motor disorder symptoms associated with multiple sclerosis. This study aims to demonstrate the potential improvements in postural control among patients with multiple sclerosis who complete a telerehabilitation program that represents a feasible alternative to physical therapy for situations in which conventional treatment is not available. Fifty patients were recruited. Control group (n = 25 received physiotherapy treatment twice a week (40 min per session. Experimental group (n = 25 received monitored telerehabilitation treatment via videoconference using the Xbox 360® and Kinect console. Experimental group attended 40 sessions, four sessions per week (20 min per session.The treatment schedule lasted 10 weeks for both groups. A computerized dynamic posturography (Sensory Organization Test was used to evaluate all patients at baseline and at the end of the treatment protocol. Results showed an improvement over general balance in both groups. Visual preference and the contribution of vestibular information yielded significant differences in the experimental group. Our results demonstrated that a telerehabilitation program based on a virtual reality system allows one to optimize the sensory information processing and integration systems necessary to maintain the balance and postural control of people with multiple sclerosis. We suggest that our virtual reality program enables anticipatory PC and response mechanisms and might serve as a successful therapeutic alternative in situations in which conventional therapy is not readily available.

  19. A telerehabilitation program improves postural control in multiple sclerosis patients: a Spanish preliminary study.

    Science.gov (United States)

    Ortiz-Gutiérrez, Rosa; Cano-de-la-Cuerda, Roberto; Galán-del-Río, Fernando; Alguacil-Diego, Isabel María; Palacios-Ceña, Domingo; Miangolarra-Page, Juan Carlos

    2013-10-31

    Postural control disorders are among the most frequent motor disorder symptoms associated with multiple sclerosis. This study aims to demonstrate the potential improvements in postural control among patients with multiple sclerosis who complete a telerehabilitation program that represents a feasible alternative to physical therapy for situations in which conventional treatment is not available. Fifty patients were recruited. Control group (n = 25) received physiotherapy treatment twice a week (40 min per session). Experimental group (n = 25) received monitored telerehabilitation treatment via videoconference using the Xbox 360® and Kinect console. Experimental group attended 40 sessions, four sessions per week (20 min per session).The treatment schedule lasted 10 weeks for both groups. A computerized dynamic posturography (Sensory Organization Test) was used to evaluate all patients at baseline and at the end of the treatment protocol. Results showed an improvement over general balance in both groups. Visual preference and the contribution of vestibular information yielded significant differences in the experimental group. Our results demonstrated that a telerehabilitation program based on a virtual reality system allows one to optimize the sensory information processing and integration systems necessary to maintain the balance and postural control of people with multiple sclerosis. We suggest that our virtual reality program enables anticipatory PC and response mechanisms and might serve as a successful therapeutic alternative in situations in which conventional therapy is not readily available.

  20. Ankle and hip postural strategies defined by joint torques

    Science.gov (United States)

    Runge, C. F.; Shupert, C. L.; Horak, F. B.; Zajac, F. E.; Peterson, B. W. (Principal Investigator)

    1999-01-01

    Previous studies have identified two discrete strategies for the control of posture in the sagittal plane based on EMG activations, body kinematics, and ground reaction forces. The ankle strategy was characterized by body sway resembling a single-segment-inverted pendulum and was elicited on flat support surfaces. In contrast, the hip strategy was characterized by body sway resembling a double-segment inverted pendulum divided at the hip and was elicited on short or compliant support surfaces. However, biomechanical optimization models have suggested that hip strategy should be observed in response to fast translations on a flat surface also, provided the feet are constrained to remain in contact with the floor and the knee is constrained to remain straight. The purpose of this study was to examine the experimental evidence for hip strategy in postural responses to backward translations of a flat support surface and to determine whether analyses of joint torques would provide evidence for two separate postural strategies. Normal subjects standing on a flat support surface were translated backward with a range of velocities from fast (55 cm/s) to slow (5 cm/s). EMG activations and joint kinematics showed pattern changes consistent with previous experimental descriptions of mixed hip and ankle strategy with increasing platform velocity. Joint torque analyses revealed the addition of a hip flexor torque to the ankle plantarflexor torque during fast translations. This finding indicates the addition of hip strategy to ankle strategy to produce a continuum of postural responses. Hip torque without accompanying ankle torque (pure hip strategy) was not observed. Although postural control strategies have previously been defined by how the body moves, we conclude that joint torques, which indicate how body movements are produced, are useful in defining postural control strategies. These results also illustrate how the biomechanics of the body can transform discrete control

  1. Anticipatory salivary flow to the sight of different foods.

    Science.gov (United States)

    Christensen, C M; Navazesh, M

    1984-12-01

    Anticipatory salivary flow was measured to the sight of seven foods that varied in texture, composition and palatability. In one experiment, subjects consumed the test foods that were viewed. This group was tested both during conditions of hunger and satiation. In a second experiment, subjects were instructed that they would not consume the foods that were viewed. Salivary responses were not related to the anticipated palability of the test foods but rather appeared to be related to the physical and chemical properties of the foods. Pizza, chocolate cake and gelatin were rated as highly palatable, but significant salivary increases occurred only with pizza. Of all the test foods, the greatest salivary flow increases were observed to the sight of lemon slices and pizza, and both foods contain sour or pungent ingredients. Hunger state and the expectation of consuming the test foods did not systematically affect the pattern or magnitude of salivary responses.

  2. Using Anticipatory Reading Guides to Improve Elementary Students’ Comprehension

    Directory of Open Access Journals (Sweden)

    Evan Ortlieb

    2013-07-01

    Full Text Available One of the greatest challenges of an elementary school teacher is equipping students with comprehension strategies that transfer to all content areas. With stable levels of reading achievement over the last two decades in the United States, it is necessary that further research be conducted on methods of increasing students’ comprehension proficiencies. This experimental research study explores the use of an anticipatory reading guide with third grade struggling readers across multiple subject areas. Findings indicate that the experimental treatment group outperformed the control group by a statistically significant rate on both reading and content area measures, indicating that when struggling readers practice and use strategies to explicitly think what will be asked of them after reading the passage they perform at higher levels.

  3. Do anticipatory grief and preparedness affect distress in bereaved caregivers?

    DEFF Research Database (Denmark)

    Nielsen, Mette Kjærgaard

    Objective Family caregivers of terminally ill patients are in a vulnerable position, and previous studies show that bereaved caregivers are at risk of psychological distress. Pre-loss grief symptoms seem to predict post-loss psychological distress, while preparedness for a looming loss tends...... to decrease distress. The aim of this nation-wide study was to investigate the association of both anticipatory grief symptoms and preparedness with psychological distress in bereaved family caregivers. Methods A list of all adult patients in Denmark receiving drug reimbursement for terminal illness...... months after the loss. The baseline questionnaire included a pre-loss version of the Prolonged Grief-13 and one question regarding caregiver preparedness, while the follow-up questionnaire contained the Prolonged Grief-13 and Beck’s Depression Inventory II. Results Of the contacted 9,512 patients 3...

  4. Individual differences in chemotherapy-induced anticipatory nausea

    Directory of Open Access Journals (Sweden)

    Marcial eRodríguez

    2013-08-01

    Full Text Available Anticipatory Nausea (AN is a severe side effect of chemotherapy that can lead cancer patients to discontinue their treatment. This kind of nausea is usually elicited by the re-exposure of the patients to the clinical context they need to attend to be treated. There has been considerable agreement that AN represents a paradigmatic example of Pavlovian conditioning, and within this framework, several behavioral interventions have been proposed in order to prevent this psychopathology. However, some studies have questioned the validity of the Pavlovian approach, suggesting that CS-US associations are neither necessary nor sufficient for AN to occur. The data and the alternative theories behind such criticisms are discussed. Additionally, it is suggested that animal models of AN could be enriched by taking into account rats’ individual differences.

  5. Risk Factors for Anticipatory Grief in Family Members of Terminally Ill Veterans Receiving Palliative Care Services.

    Science.gov (United States)

    Burke, Laurie A; Clark, Karen A; Ali, Khatidja S; Gibson, Benjamin W; Smigelsky, Melissa A; Neimeyer, Robert A

    2015-01-01

    Anticipatory grief is the process associated with grieving the loss of loved ones in advance of their inevitable death. Because anticipatory grief has been associated with a variety of outcomes, risk factors for this condition deserve closer consideration. Fifty-seven family members of terminally ill, hospice-eligible veterans receiving palliative care services completed measures assessing psychosocial factors and conditions. Elevated anticipatory grief was found in families characterized by relational dependency, lower education, and poor grief-specific support, who also experienced discomfort with closeness and intimacy, neuroticism, spiritual crisis, and an inability to make sense of the loss. Thus, in this sample, anticipatory grief appears to be part of a cluster of factors and associated distress that call for early monitoring and possible intervention.

  6. An evolving science-society contract in India: The search for legitimacy in anticipatory risk governance

    NARCIS (Netherlands)

    Gupta, A.

    2011-01-01

    This article analyzes evolving institutions and practices of anticipatory risk governance in India, through the lens of two recent and highly controversial developments in governing genetically modified crops in Indian agriculture. These developments include, first, conflicts over approving (or not)

  7. Postural control during standing reach in children with Down syndrome.

    Science.gov (United States)

    Chen, Hao-Ling; Yeh, Chun-Fu; Howe, Tsu-Hsin

    2015-03-01

    The purpose of the present study was to investigate the dynamic postural control of children with Down syndrome (DS). Specifically, we compared postural control and goal-directed reaching performance between children with DS and typically developing children during standing reach. Standing reach performance was analyzed in three main phases using the kinematic and kinetic data collected from a force plate and a motion capture system. Fourteen children with DS, age and gender matched with fourteen typically developing children, were recruited for this study. The results showed that the demand of the standing reach task affected both dynamic postural control and reaching performance in children with DS, especially in the condition of beyond arm's length reaching. More postural adjustment strategies were recruited when reaching distance was beyond arm's length. Children with DS tended to use inefficient and conservative strategies for postural stability and reaching. That is, children with DS perform standing reach with increased reaction and execution time and decreased amplitudes of center of pressure displacements. Standing reach resembled functional balance that is required in daily activities. It is suggested to be considered as a part of strength and balance training program with graded task difficulty.

  8. 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.

  9. 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.

  10. Anticipatory control of grasping: independence of sensorimotor memories for kinematics and kinetics.

    Science.gov (United States)

    Lukos, Jamie R; Ansuini, Caterina; Santello, Marco

    2008-11-26

    We have recently provided evidence for anticipatory grasp control mechanisms in the kinematic domain by showing that subjects modulate digit placement on an object based on its center of mass (CM) when it can be anticipated (Lukos et al., 2007). This behavior relied on sensorimotor memories about digit contact points and forces required for optimal manipulation. We found that accurate sensorimotor memories depended on the acquisition of implicit knowledge about object properties associated with repeated manipulations of the same object. Whereas implicit knowledge of object properties is essential for anticipatory grasp control, the extent to which subjects can use explicit knowledge to accurately scale digit forces in an anticipatory manner is controversial. Additionally, it is not known whether subjects are able to use explicit knowledge of object properties for anticipatory control of contact points. We addressed this question by asking subjects to grasp and lift an object while providing explicit knowledge of object CM location as visual or verbal cues. Contact point modulation and object roll, a measure of anticipatory force control, were assessed using blocked and random CM presentations. We found that explicit knowledge of object CM enabled subjects to modulate contact points. In contrast, subjects could not minimize object roll in the random condition to the same extent as in the blocked when provided with a verbal or visual cue. These findings point to a dissociation in the effect of explicit knowledge of object properties on grasp kinematics versus kinetics, thus suggesting independent anticipatory processes for grasping.

  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. Postural stabilization and balance assessment in Charcot-Marie-Tooth 1A subjects.

    Science.gov (United States)

    Lencioni, T; Rabuffetti, M; Piscosquito, G; Pareyson, D; Aiello, A; Di Sipio, E; Padua, L; Stra, F; Ferrarin, M

    2014-09-01

    The aim of the present study was to assess postural stabilization skill in adult subjects affected by Charcot-Marie-Tooth disease (CMT) type 1A. For this purpose ground reaction force (GRF) was measured by means of a piezoelectric force platform during the sit-to-stand (STS) movement, until a steady state erect posture was achieved. Specific indexes to quantify Centre of Mass acceleration, both during postural stabilization and during quiet standing, were computed using a mathematical model. Forty-seven CMT1A subjects were recruited for the study, and the control group was formed by forty-one age- and sex-matched healthy subjects. The results show that CMT1A subjects are less stable than controls during the quiet stance. Greater difficulty (high values of Yinf, the final instability rate) to maintain erect posture appears to be mainly associated with plantar-flexor muscle weakness, rather than to damage of the proprioceptive system. The worst performances shown by CMT1A subjects in the stabilization phase (high values of I, the global index of postural stabilization performance) seem to be associated with reduced muscle strength and the loss of large sensory nerve fibres. Distal muscle weakness appears to affect both postural stabilization and quiet erect posture. The presented protocol and the analysis of postural stabilization parameters provide useful information on CMT1A balance disorders.

  13. A comparison of low back kinetic estimates obtained through posture matching, rigid link modeling and an EMG-assisted model.

    Science.gov (United States)

    Parkinson, R J; Bezaire, M; Callaghan, J P

    2011-07-01

    This study examined errors introduced by a posture matching approach (3DMatch) relative to dynamic three-dimensional rigid link and EMG-assisted models. Eighty-eight lifting trials of various combinations of heights (floor, 0.67, 1.2 m), asymmetry (left, right and center) and mass (7.6 and 9.7 kg) were videotaped while spine postures, ground reaction forces, segment orientations and muscle activations were documented and used to estimate joint moments and forces (L5/S1). Posture matching over predicted peak and cumulative extension moment (p posture matching or EMG-assisted approaches (p = 0.7987). Posture matching over predicted cumulative (p posture matching provides a method to analyze industrial lifting exposures that will predict kinetic values similar to those of more sophisticated models, provided necessary corrections are applied.

  14. The Contribution of Pre-impact Spine Posture on Human Body Model Response in Whole-body Side Impact.

    Science.gov (United States)

    Poulard, David; Subit, Damien; Donlon, John-Paul; Lessley, David J; Kim, Taewung; Park, Gwansik; Kent, Richard W

    2014-11-01

    The objective of the study was to analyze independently the contribution of pre-impact spine posture on impact response by subjecting a finite element human body model (HBM) to whole-body, lateral impacts. Seven postured models were created from the original HBM: one matching the standard driving posture and six matching pre-impact posture measured for each of six subjects tested in previously published experiments. The same measurements as those obtained during the experiments were calculated from the simulations, and biofidelity metrics based on signals correlation were established to compare the response of HBM to that of the cadavers. HBM responses showed good correlation with the subject response for the reaction forces, the rib strain (correlation score=0.8) and the overall kinematics. The pre-impact posture was found to greatly alter the reaction forces, deflections and the strain time histories mainly in terms of time delay. By modifying only the posture of HBM, the variability in the impact response was found to be equivalent to that observed in the experiments performed with cadavers with different anthropometries. The patterns observed in the responses of the postured HBM indicate that the inclination of the spine in the frontal plane plays a major role. The postured HBM sustained from 2 to 5 bone fractures, including the scapula in some cases, confirming that the pre-impact posture influences the injury outcome predicted by the simulation.

  15. Independent and convergent signals from the pontomedullary reticular formation contribute to the control of posture and movement during reaching in the cat.

    Science.gov (United States)

    Schepens, Bénédicte; Drew, Trevor

    2004-10-01

    We have addressed the nature of the postural control signals contained within the discharge activity of neurons in the pontomedullary reticular formation, including reticulospinal neurons, during a reaching task in the cat. We recorded the activity of 142 neurons during ipsilateral reaching movements that required anticipatory postural adjustments (APAs) in the supporting limbs to maintain equilibrium. Discharge activity in 82/142 (58%) neurons was significantly increased before the onset of the reach. Most of these neurons discharged either in a phasic (22/82), tonic (10/82), or phasic/tonic (41/82) pattern. In each of these 3 groups, the onset of the discharge activity in some neurons was temporally related either to the go signal or to the onset of the movement. In many neurons, one component of the discharge sequence was better related to the go signal and another to the onset of the movement. Based on our previous behavioral study during the same task, we suggest that reticular neurons in which the discharge activity is better related to the go signal contribute to the initiation of the APAs that precede the movement. Neurons in which the discharge activity is better related to the movement signal might contribute to the initiation of the movement and to the production of the postural responses that accompany that movement. Together our results suggest the existence of neurons that signal posture and movement independently and others that encode a convergent signal that contributes to the control of both posture and movement.

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

    Science.gov (United States)

    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

  17. 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...

  18. 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 ...

  19. 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.

  20. Anticipatory processes under academic stress: an ERP study.

    Science.gov (United States)

    Duan, Hongxia; Yuan, Yiran; Yang, Can; Zhang, Liang; Zhang, Kan; Wu, Jianhui

    2015-03-01

    It is well known that preparing for and taking high-stakes exams has a significant influence on the emotional and physiological wellbeing of exam-takers, but few studies have investigated the resulting cognitive changes. The current study examined the effect of examination-induced academic stress on anticipation in information processing. Anticipation was indexed using the contingent negative variation (CNV). Electroencephalograms (EEG) were collected from 42 participants using the classic S1-S2 paradigm. These participants were preparing for the Chinese National Postgraduate Entrance Exam (NPEE). EEGs were also collected from 21 age-matched, non-exam comparison participants. The levels of perceived stress and state anxiety were higher and both the initial CNV (iCNV) and the late CNV (lCNV) were more negative in the exam group than in the non-exam group. These results suggest that participants under academic stress experienced greater anticipation of upcoming events. More important, for the non-exam group, state anxiety was positively related to both the iCNV and lCNV amplitude, and this correlation existed when trait anxiety was controlled; however, there was no such relationship in the exam group. These results suggested that the cortical anticipatory activity in the high-stressed exam group reached the maximum ceiling, leaving little room for transient increases in state anxiety.

  1. Engineering imaginaries: Anticipatory foresight for solar radiation management governance.

    Science.gov (United States)

    Low, Sean

    2017-02-15

    Since solar radiation management (SRM) technologies do not yet exist and capacities to model their impacts are limited, proposals for its governance are implicitly designed not around realities, but possibilities - baskets of risk and benefit that are often components of future imaginaries. This paper reports on the project Solar Radiation Management: Foresight for Governance (SRM4G), which aimed to encourage an anticipatory mode of thinking about the future of an engineered climate. Leveraging the participation of 15 scholars and practitioners heavily engaged in early conversations on SRM governance, SRM4G applied scenario construction to generate a set of alternative futures leading to 2030, each exercising different influences on the need for - and challenges associated with - development of SRM technologies. The scenarios then provided the context for the design of systems of governance with the capacity and legitimacy to respond to those challenges, and for the evaluation of the advantages and drawbacks of different options against a wide range of imaginary but plausible futures. SRM4G sought to initiate a conversation within the SRM research community on the capacity of foresight approaches to highlight the centrality of conceptions of the future to discussions of SRM's threats and opportunities, and in doing so, examined and challenged the assumptions embedded in conceptualizing SRM's aims, development and governance, and discussed the capacity of governance options to adapt to a wide range of possibilities.

  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. The Effect of Massage on Anticipatory Anxiety and Procedural Pain in Patients with Burn Injury

    Science.gov (United States)

    Najafi Ghezeljeh, Tahereh; Mohades Ardebili, Fatimah; Rafii, Forough; Manafi, Farzad

    2017-01-01

    BACKGROUND Pain related to burn injuries is one of the most troublesome pain intensity. This study aimed to investigate the effect of massage on anticipatory anxiety, procedural pain intensity, vital signs and relaxation level of patients with burn injury. METHODS In this quasi-experimental study, through convenience sampling, 60 hospitalized adult burn patients were selected from a specialized burn and reconstructive hospital. Subjects were assigned to massage and control groups through simple randomization. Massage was offered by using non aromatic oil about 10-15 minutes before wound care on intact part of the body once a day for 20 minutes on patients’ bedside for 3 consecutive days. In the 3 days, the control group did not received any massage and were asked to stay at bed. Demographic and clinical characteristics and vital signs, Visual Analogue Scale and the Persian version of Burn Specific Pain Anxiety Scale were used to determine baseline and procedural pain, anxiety and relaxation levels and anticipatory anxiety. RESULTS No significant difference was noted between mean score of pain intensity, anxiety and relaxation level, and vital signs in massage and control groups after intervention following wound care. In massage and control groups, there was no significant differences between mean scores of anticipatory anxiety before and after intervention. There was no significant difference between the mean scores of anticipatory anxiety in massage and control groups after intervention prior wound care. CONCLUSION Massage was shown not to have any effect on anticipatory anxiety and procedural pain. PMID:28289612

  7. Preparing for communication interactions: the value of anticipatory strategies for adults with hearing impairment.

    Science.gov (United States)

    Tye-Murray, N

    1992-04-01

    Some people with hearing impairment may use anticipatory strategies to prepare for an upcoming communication interaction, such as a doctor's appointment. They may consider vocabulary and statements that might occur, and they may practice speechreading a partner saying the items. Experiment 1 evaluated the effectiveness of two types of anticipatory strategies: workbook activities and situation-specific lipreading practice. Two groups of normal-hearing subjects were asked to prepare for a communication interaction in a bank setting where they would be required to recognize speech using only the visual signal. Each group was assigned to one type of anticipatory strategy. A third group served as a control group. Experiment 2 evaluated whether multifaceted anticipatory practice improved cochlear implant users' ability to recognize statements and words audiovisually that might occur in a doctor's office, bank, movie theater, and gas station. One group of implanted subjects received 4 days of training, 1 day for each setting, and a second group served as a control group. In both experiments, subjects who used anticipatory strategies did not improve their performance on situation-specific sentence tests more than the control subjects.

  8. 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.

  9. 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.

  10. Preparing Children for Court: Effects of a Model Court Education Program on Children's Anticipatory Anxiety.

    Science.gov (United States)

    Nathanson, Rebecca; Saywitz, Karen J

    2015-08-01

    The current study examined whether a pretrial preparation program, consisting of legal knowledge education, stress inoculation training, and a mock trial, is associated with decreased anticipatory anxiety of child witnesses. One hundred and ninety-three 4- to 17-year-olds who were awaiting impending legal proceedings attended Kids' Court School in Las Vegas, NV, one to two weeks before their court appearances. Participants completed a measure of anticipatory court-related anxiety before and after the intervention. As predicted, children's anticipatory anxiety decreased significantly from pretest to posttest. Results demonstrate the promise of a brief, unbiased, standardized program for reducing system-induced stress on child witnesses, while maintaining the integrity of the legal process. This study serves as a springboard to guide future research, practice, policy, and implementation on a larger scale.

  11. Transition from anticipatory to lag synchronization via complete synchronization in time-delay systems.

    Science.gov (United States)

    Senthilkumar, D V; Lakshmanan, M

    2005-01-01

    The existence of anticipatory, complete, and lag synchronization in a single system having two different time delays, that is, feedback delay tau1 and coupling delay tau2, is identified. The transition from anticipatory to complete synchronization and from complete to lag synchronization as a function of coupling delay tau2 with a suitable stability condition is discussed. In particular, it is shown that the stability condition is independent of the delay times tau1 and tau2. Consequently, for a fixed set of parameters, all the three types of synchronizations can be realized. Further, the emergence of exact anticipatory, complete, or lag synchronization from the desynchronized state via approximate synchronization, when one of the system parameters (b2) is varied, is characterized by a minimum of the similarity function and the transition from on-off intermittency via periodic structure in the laminar phase distribution.

  12. Existence of anticipatory, complete and lag synchronizations in time-delay systems

    Energy Technology Data Exchange (ETDEWEB)

    Senthilkumar, D V; Lakshmanan, M [Centre for Nonlinear Dynamics, Department of Physics, Bharathidasan University, Tiruchirapalli - 620 024 (India)

    2005-01-01

    Existence of different kinds of synchronizations, namely anticipatory, complete and lag type synchronizations (both exact and approximate), are shown to be possible in timedelay coupled piecewise linear systems. We deduce stability condition for synchronization of such unidirectionally coupled systems following Krasovskii-Lyapunov theory. Transition from anticipatory to lag synchronization via complete synchronization as a function of coupling delay is discussed. The existence of exact synchronization is preceded by a region of approximate synchronization from desynchronized state as a function of a system parameter, whose value determines the stability condition for synchronization. The results are corroborated by the nature of similarity functions. A new type of oscillating synchronization that oscillates between anticipatory, complete and lag synchronization, is identified as a consequence of delay time modulation with suitable stability condition.

  13. Dopamine is involved in food-anticipatory activity in mice.

    Science.gov (United States)

    Liu, Yuan-Yuan; Liu, Tian-Ya; Qu, Wei-Min; Hong, Zong-Yuan; Urade, Yoshihiro; Huang, Zhi-Li

    2012-10-01

    When food is available during a restricted and predictable time of the day, mammals exhibit food-anticipatory activity (FAA), an increase in locomotor activity preceding the presentation of food. Although many studies have attempted to locate the food-entrainable circadian oscillator in the central nervous system, the pathways that mediate food entrainment are a matter of controversy. The present study was designed to determine the role of dopaminergic and histaminergic systems on FAA. Mice were given access to food for 2 h (ZT12-ZT14), and FAA was defined as the locomotor activity that occurred 2 h before the availability of food. Dopamine D(1) receptor (R), D(2)R, and histamine H(1)R-specific antagonists were used to clarify the role of dopamine and histamine receptors in FAA induced by food restriction (FR). FAA was monitored by infrared locomotor activity sensors. Mice were sacrificed at ZT12 on the 14th day of FR, and monoamine concentrations were determined by high-performance liquid chromatography coupled to electrochemical detection (HPLC-ECD). The results showed that pretreatment with the D(1)R antagonist SCH23390 at 1, 3, or 10 µg/kg significantly reduced FAA by 19% (p antagonist raclopride at 22, 67, or 200 µg/kg significantly reduced FAA by 16% (p dopamine and its metabolites in the striatum and midbrain were significantly increased during FAA, even with the pretreatment of D(1)R and D(2)R antagonists. However, pretreatment with pyrilamine at 2.5, 5, or 10 mg/kg did not significantly reduce FAA, although it reduced the locomotor activity during the dark period in ad libitum mice. These results strongly indicate that the dopaminergic system plays an essential role in the FAA in mice.

  14. Robust food anticipatory activity in BMAL1-deficient mice.

    Directory of Open Access Journals (Sweden)

    Julie S Pendergast

    Full Text Available Food availability is a potent environmental cue that directs circadian locomotor activity in rodents. Even though nocturnal rodents prefer to forage at night, daytime food anticipatory activity (FAA is observed prior to short meals presented at a scheduled time of day. Under this restricted feeding regimen, rodents exhibit two distinct bouts of activity, a nocturnal activity rhythm that is entrained to the light-dark cycle and controlled by the master clock in the suprachiasmatic nuclei (SCN and a daytime bout of activity that is phase-locked to mealtime. FAA also occurs during food deprivation, suggesting that a food-entrainable oscillator (FEO keeps time in the absence of scheduled feeding. Previous studies have demonstrated that the FEO is anatomically distinct from the SCN and that FAA is observed in mice lacking some circadian genes essential for timekeeping in the SCN. In the current study, we optimized the conditions for examining FAA during restricted feeding and food deprivation in mice lacking functional BMAL1, which is critical for circadian rhythm generation in the SCN. We found that BMAL1-deficient mice displayed FAA during restricted feeding in 12hr light:12hr dark (12L:12D and 18L:6D lighting cycles, but distinct activity during food deprivation was observed only in 18L:6D. While BMAL1-deficient mice also exhibited robust FAA during restricted feeding in constant darkness, mice were hyperactive during food deprivation so it was not clear that FAA consistently occurred at the time of previously scheduled food availability. Taken together, our findings suggest that optimization of experimental conditions such as photoperiod may be necessary to visualize FAA in genetically modified mice. Furthermore, the expression of FAA may be possible without a circadian oscillator that depends on BMAL1.

  15. [Influence of preliminary information about mass on anticipatory muscle activity during catching of falling object].

    Science.gov (United States)

    Kazennikov, O V; Lipshits, M I

    2010-01-01

    Heavy or light object fell into the cup held between thumb and index fingers of sitting subject. The anticipatory muscle activity and the grip force applied to cup depended on the mass of object while the temporal parameters (time of beginning of muscle activity, duration of the activity, the time of grip force maximum) were constant. The preliminary verbal information about mass of the falling object was enough for predictive force programming. Without such information, i.e. during fall the object of unknown mass the anticipatory activity was planned in expectation of heavy weight.

  16. Anticipatory Guidance and Psychoeducation as a Standard of Care in Pediatric Oncology.

    Science.gov (United States)

    Thompson, Amanda L; Young-Saleme, Tammi K

    2015-12-01

    The aim of this review was to critically evaluate the literature on anticipatory guidance and psychoeducation for youth with cancer and their caregivers. Twenty-one publications were identified. Overall, psychoeducation efforts and interventions were well-liked and accepted by patients and caregivers, improved patient and family knowledge about childhood cancer, and increased patient's health locus of control. A number of modalities are effective in giving families anticipatory guidance, provided the content and delivery are matched to the needs and preferences of individual patients and caregivers. Evidence supports a strong recommendation for psychoeducation for youth with cancer and their families.

  17. Effects of adiposity on postural control and cognition.

    Science.gov (United States)

    Meng, Hao; O'Connor, Daniel P; Lee, Beom-Chan; Layne, Charles S; Gorniak, Stacey L

    2016-01-01

    In the U.S., it is estimated that over one-third of adults are obese (Body Mass Index (BMI)>30kg/m(2)). Previous studies suggest that obesity may be associated with deficits in cognitive performance and postural control. Increased BMI may challenge cognitive and postural performance in a variety of populations; however, most relevant studies have classified participants based on BMI values, which cannot be used to accurately assess the effects of adiposity on cognitive performance and postural control. The objective of the current study was to examine motor and cognitive responses for overweight and obese adults compared to normal weight individuals by using both BMI and adiposity measures. Ten normal weight (BMI=18-24.9kg/m(2)), ten overweight (BMI=25-29.9kg/m(2)), and ten obese (BMI=30-40kg/m(2)) adults were evaluated (age: 24±4 years). Participants were classified into three groups based on BMI values at the onset of the study, prior to body composition analysis. Participants performed (1) working memory task while maintaining upright stance, and (2) a battery of sensorimotor evaluations. Working memory reaction times, response accuracy, center-of-pressure (COP) path length, velocity, migration area, time to boundary values in anterior-posterior direction, and ankle-hip strategy-scores were calculated to evaluate cognitive-motor performance. No significant deficits in working memory performance were observed. Overall, measures of motor function deteriorated as BMI and body fat percentage increased. The relationship between deteriorating postural performance indices and body fat percentage were greater than those found between BMI and postural performance indices.

  18. 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.

  19. 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.

  20. 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

  1. Perturbations of ground support alter posture and locomotion coupling during step initiation in Parkinson's disease.

    Science.gov (United States)

    Rogers, Mark W; Hilliard, Marjorie Johnson; Martinez, Katherine M; Zhang, Yunhui; Simuni, Tanya; Mille, Marie-Laure

    2011-02-01

    During the initiation of stepping, anticipatory postural adjustments (APAs) for lateral weight transfer and propulsion normally precede the onset of locomotion. In Parkinson's disease (PD), impaired step initiation typically involves altered APA ground force production with delayed step onset and deficits in stepping performance. If, as in stance and gait, sensory information about lower limb load is important for the control of stepping, then perturbations influencing loading conditions could affect the step initiation process. This study investigated the influence of changes in lower limb loading during step initiation in patients with PD and healthy control subjects. Participants performed rapid self-triggered step initiation with the impending single stance limb positioned over a pneumatically actuated platform. In perturbation trials, the stance limb ground support surface was either moved vertically downward (DROP) or upward (ELEVATE) by 1.5 cm shortly after the onset of the APA phase. Overall, PD patients demonstrated a longer APA duration, longer time to first step onset, and slower step speed than controls. In both groups, the DROP perturbation reinforced the intended APA kinetic changes for lateral weight transfer and resulted in a significant reduction in APA duration, increase in peak amplitude, and earlier time to first step onset compared with other conditions. During ELEVATE trials that opposed the intended weight transfer forces both groups rapidly adapted their stepping to preserve standing stability by decreasing step length and duration, and increasing step height and foot placement laterally. The findings suggested that sensory information associated with limb load and/or foot pressure modulates the spatial and temporal parameters of posture and locomotion components of step initiation in interaction with a centrally generated feedforward mode of neural control. Moreover, impaired step initiation in PD may at least acutely be enhanced by

  2. 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.

  3. 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.

  4. Development of Postural Muscles and Their Innervation

    Directory of Open Access Journals (Sweden)

    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.

  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. Anticipatory 50 kHz ultrasonic vocalizations are associated with escalated alcohol intake in dependent rats.

    Science.gov (United States)

    Buck, Cara L; Malavar, Jordan C; George, Olivier; Koob, George F; Vendruscolo, Leandro F

    2014-09-01

    Rats emit 50kHz ultrasonic vocalizations (USVs) in situations of increased motivation, such as during the anticipation of palatable food or drugs of abuse. Whether the same holds true for the anticipation of alcohol intake remains unknown. Alcohol drinking in a nondependent state is thought to be mediated by its rewarding effects (positive reinforcement), whereas drinking in the dependent state is motivated by alcohol's stress-relieving effects (negative reinforcement). Here, we measured context-elicited 50kHz USVs in alcohol-dependent (alcohol vapor-exposed) and nondependent rats immediately before operant alcohol self-administration sessions. Dependent rats showed escalated levels of alcohol intake compared with nondependent rats. Overall, dependent and nondependent rats showed similar levels of anticipatory 50kHz USVs. However, the number of anticipatory USVs was positively correlated with alcohol intake in dependent rats but not nondependent rats. Additionally, dependent rats with higher alcohol intake displayed increased anticipatory 50kHz USVs compared with rats that had lower alcohol intake, whereas no difference was observed between rats with high and low alcohol intake in the nondependent group. Increased 50kHz USVs were specific for the anticipation of alcohol self-administration and did not generalize to a novel environment. These findings suggest that anticipatory 50kHz USVs may be an indicator of context-elicited negative reinforcement learning.

  7. The Integrity of Anticipatory Coarticulation in Fluent and Non-Fluent Tokens of Adults Who Stutter

    Science.gov (United States)

    Sussman, Harvey M.; Byrd, Courtney T.; Guitar, Barry

    2011-01-01

    This article analysed the acoustic structure of voiced stop ++ vowel sequences in a group of persons who stutter (PWS). This phonetic unit was chosen because successful production is highly dependent on the differential tweaking of right-to-left anticipatory coarticulation as a function of stop place. Thus, essential elements of both speech motor…

  8. The Effects of Age and Preoral Sensorimotor Cues on Anticipatory Mouth Movement During Swallowing

    Science.gov (United States)

    Moon, Jerald B.; Goodman, Shawn S.

    2016-01-01

    Purpose The aim of this study was to investigate the effects of preoral sensorimotor cues on anticipatory swallowing/eating-related mouth movements in older and younger adults. It was hypothesized that these cues are essential to timing anticipatory oral motor patterns, and these movements are delayed in older as compared with younger adults. Method Using a 2 × 2 repeated-measures design, eating-related lip, jaw, and hand movements were recorded from 24 healthy older (ages 70–85 years) and 24 healthy younger (ages 18–30 years) adults under 4 conditions: typical self-feeding, typical assisted feeding (proprioceptive loss), sensory-loss self-feeding (auditory and visual loss/degradation), and sensory-loss assisted feeding (loss/degradation of all cues). Results All participants demonstrated anticipatory mouth opening. The absence of proprioception delayed lip-lowering onset, and sensory loss more negatively affected offset. Given at least 1 preoral sensorimotor cue, older adults initiated movement earlier than younger adults. Conclusions Preoral sensorimotor information influences anticipatory swallowing/eating-related mouth movements, highlighting the importance of these cues. Earlier movement in older adults may be a compensation, facilitating safe swallowing given other age-related declines. Further research is needed to determine if the negative impact of cue removal may be further exacerbated in a nonhealthy system (e.g., presence of dysphagia or disease), potentially increasing swallowing- and eating-related risks. PMID:26540553

  9. Searching for behavioral indicators of welfare in zoos: uncovering anticipatory behavior.

    Science.gov (United States)

    Watters, Jason V

    2014-01-01

    A current focus of zoo-based research aims to identify indicators of animal welfare. Reliable behavioral indicators of welfare are highly desirable as behavioral observation is non invasive and requires little in the way of specialized equipment and other costly resources-save for observer time. Anticipatory behavior is an indicator of an animal's sensitivity to reward and as such, it is a real-time indicator of animals' own perceptions of their well-being. In fact, anticipatory behavior may generate a positive affective state and thus be at least a brief manifestation of good welfare itself. The husbandry conditions of most captive animals are such that food acquisition and other positive outcomes are highly scheduled and easily signaled. These conditions promote the development of anticipatory behavior, yet little research has either documented or interpreted this behavior in zoo and aquarium animals. This commentary suggests that anticipatory behavior could be a useful tool for assessing welfare and calls upon zoo and aquarium researchers to begin to develop this tool by describing the behavior and the circumstances that lead to its modulation.

  10. Verbal and nonverbal predictors of language-mediated anticipatory eye movements

    NARCIS (Netherlands)

    Rommers, J.; Meyer, A.S.; Hüttig, F.

    2015-01-01

    During language comprehension, listeners often anticipate upcoming information. This can draw listeners' overt attention to visually presented objects before the objects are referred to. We investigated to what extent the anticipatory mechanisms involved in such language-mediated attention rely on s

  11. Development of anticipatory orienting strategies and trajectory formation in goal-oriented locomotion.

    Science.gov (United States)

    Belmonti, Vittorio; Cioni, Giovanni; Berthoz, Alain

    2013-05-01

    In goal-oriented locomotion, healthy adults generate highly stereotyped trajectories and a consistent anticipatory head orienting behaviour, both evidence of top-down, open-loop control. The aim of this study is to describe the typical development of anticipatory orienting strategies and trajectory formation. Our hypothesis is that full-blown anticipatory control requires advanced navigational skills. Twenty-six healthy subjects (14 children: 4-11 years; 6 adolescents: 13-17 years; 6 adults) were asked to walk freely towards one of the three visual targets, in a randomised order. Movement was captured via an optoelectronic system, with 15 body markers. The whole-body displacement, yaw orientation of head, trunk and pelvis, heading direction and foot placements were extracted. Head-heading anticipation, trajectory curvature, indexes of variability of trajectories, foot placements and kinematic profiles were studied. The mean head-heading anticipation time and trajectory curvature did not significantly differ among age groups. In children, however, head anticipation was more often lacking (χ2 = 9.55, p children, while it became consistently lower in adolescence (χ2 = 78.59, p spatial and kinematic variability all followed a decreasing developmental trend (R (2) > 0.5, p children under 11 do not perform curvilinear locomotor trajectories as adolescents and adults do. Anticipatory head orientation and trajectory formation develop in late childhood, well after gait maturation. Navigational skills, such as path planning and shifting from ego- to allocentric spatial reference frames, are proposed as necessary requisites for mature locomotor control.

  12. Hubungan Coping Style dan Anticipatory Grief pada Orangtua Anak yang Didiagnosis Kanker

    Directory of Open Access Journals (Sweden)

    Putri Lenggo Geni

    2013-03-01

    Full Text Available Everyone copes with stressful events in his/her life differently. Three strategies in dealing with stress include problem-focused coping, emotion-focused coping, and religious-focused coping. Death of loved ones has been considered one of the major sources of stress in individuals and poses threat to their well-being and adjustment if ones failed to cope with the grief. Interestingly, previous studies show that families and caregivers of terminally ill patients suffered bereavement prior to the actual death, a phenomenon labeled anticipatory grief. Article presents a study with the purpose to investigate the relationship between different coping styles and anticipatory grief in parents of children diagnosed with cancer. Fifty-five parents, ranging from 20 to 60-year-old, participated in this study. Results revealed that coping style, particularly emotion-focused coping, significantly predict anticipatory grief in parents of children diagnosed with cancer. However, both problem-focused coping and religious-focused coping did not predict parental anticipatory grief in this study.

  13. Participatory and Anticipatory Stages of Mathematical Concept Learning: Further Empirical and Theoretical Development

    Science.gov (United States)

    Simon, Martin A.; Placa, Nicora; Avitzur, Arnon

    2016-01-01

    Tzur and Simon (2004) postulated 2 stages of development in learning a mathematical concept: participatory and anticipatory. The authors discuss the affordances for research of this stage distinction related to data analysis, task design, and assessment as demonstrated in a 2-year teaching experiment.

  14. 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.

  15. 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...

  16. Evidence for time-of-day dependent effect of neurotoxic dorsomedial hypothalamic lesions on food anticipatory circadian rhythms in rats.

    Science.gov (United States)

    Landry, Glenn J; Kent, Brianne A; Patton, Danica F; Jaholkowski, Mark; Marchant, Elliott G; Mistlberger, Ralph E

    2011-01-01

    The dorsomedial hypothalamus (DMH) is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO) have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (T(b)) rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and T(b) rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and T(b) rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep.

  17. Evidence for time-of-day dependent effect of neurotoxic dorsomedial hypothalamic lesions on food anticipatory circadian rhythms in rats.

    Directory of Open Access Journals (Sweden)

    Glenn J Landry

    Full Text Available The dorsomedial hypothalamus (DMH is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (T(b rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and T(b rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and T(b rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep.

  18. Measuring Regularity of Human Postural Sway Using Approximate Entropy and Sample Entropy in Patients with Ehlers-Danlos Syndrome Hypermobility Type

    Science.gov (United States)

    Rigoldi, Chiara; Cimolin, Veronica; Camerota, Filippo; Celletti, Claudia; Albertini, Giorgio; Mainardi, Luca; Galli, Manuela

    2013-01-01

    Ligament laxity in Ehlers-Danlos syndrome hypermobility type (EDS-HT) patients can influence the intrinsic information about posture and movement and can have a negative effect on the appropriateness of postural reactions. Several measures have been proposed in literature to describe the planar migration of CoP over the base of support, and the…

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Anticipatory grip force between 1 and 3g

    Science.gov (United States)

    White, Olivier; Van Loon, ing.. Jack J. W. A.; Thonnard, Jean-Louis; Hermsdorfer, Joachim; Lefevre, Philippe

    One remarkable capacity of utilizing common tools appropriately as soon as we grasp them relies on the ability to determine in advance the grip force (GF) required to handle them in relation to their mechanical properties and the surrounding environment. This anticipatory strategy avoids the uncompressible delays in the feedback system. The predictive control of GF is made possible because the nervous system can learn, store and then select the internal representations of the dynamics of innumerable objects, known as internal models. Beside this flexibility, the nervous system's ability to learn different task dynamics is often limited in classical robotic experiments The environment itself can be profoundly modified in altered gravity or centrifugation. The few studies that investigated motor adaptation in such contexts did not consider the interaction between gravitational phases and even less the transitions across environments. Here, we tested subject's abilities to adapt to levels of gravitational fields generated by a human centrifuge. In Experiment 1, seven subjects performed 4 lifting trials in each gravitational phase (1 to 2.5g and then 2.5 to 1g by steps of 0.5g) with a 0.12 kg instrumented object. In Experiment 2, six subjects performed vertical oscillations of the object during transitions between 1 and 3g (0.5g steps, ascending and descending phases, profile repeated twice). We continuously measured GF, load force (LF) and ambient gravity. We hypothesized that participants were able to predictively adjust GF to the new environment. In Experiment 1, participants adjusted their GF proportionally to gravity and decreased GF across trials within a given gravitational environment. Preload phases decreased over time from 300ms to 50ms irrespective of gravity. We quantified the abilities of participants to switch across environments by subtracting GF recorded in the last trial in the current gravity level from GF during the first trial in the new environment

  5. [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)

  6. Postural adjustments for online corrections of arm movements in standing humans.

    Science.gov (United States)

    Leonard, Julia A; Gritsenko, Valeriya; Ouckama, Ryan; Stapley, Paul J

    2011-05-01

    The aim of this study was to investigate how humans correct ongoing arm movements while standing. Specifically, we sought to understand whether the postural adjustments in the legs required for online corrections of arm movements are predictive or rely on feedback from the moving limb. To answer this question we measured online corrections in arm and leg muscles during pointing movements while standing. Nine healthy right-handed subjects reached with their dominant arm to a visual target in front of them and aligned with their midline. In some trials, the position of the target would switch from the central target to one of the other targets located 15°, 30°, or 45° to the right of the central (midline) target. For each target correction, we measured the time at which arm kinematics, ground reaction forces, and arm and leg muscle electromyogram significantly changed in response to the target displacement. Results show that postural adjustments in the left leg preceded kinematic corrections in the limb. The corrective postural muscle activity in the left leg consistently preceded the corrective reaching muscle activity in the right arm. Our results demonstrate that corrections of arm movements in response to target displacement during stance are preceded by postural adjustments in the leg contralateral to the direction of target shift. Furthermore, postural adjustments preceded both the hand trajectory correction and the arm-muscle activity responsible for it, which suggests that the central nervous system does not depend on feedback from the moving arm to modify body posture during voluntary movement. Instead, postural adjustments lead the online correction in the arm the same way they lead the initiation of voluntary arm movements. This suggests that forward models for voluntary movements executed during stance incorporate commands for posture that are produced on the basis of the required task demands.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  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 t

  10. 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…

  11. 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…

  12. 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

  13. 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.

  14. Revisiting Bloodstein's Anticipatory Struggle Hypothesis from a psycholinguistic perspective:A Variable Release Threshold hypothesis of stuttering

    OpenAIRE

    Brocklehurst, Paul H.; Lickley, Robin J; Corley, Martin

    2013-01-01

    This paper reviews Bloodstein's (1975) Anticipatory Struggle Hypothesis of stuttering, identifies its weaknesses, and proposes modifications to bring it into line with recent advances in psycholinguistic theory. The review concludes that the Anticipatory Struggle Hypothesis provides a plausible explanation for the variation in the severity of stuttered disfluencies across speaking situations and conversation partners. However, it fails to explain the forms that stuttered disfluencies characte...

  15. Postural Coordination during Socio-motor Improvisation.

    Science.gov (United States)

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

    2016-01-01

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

  16. Enhanced food anticipatory activity associated with enhanced activation of extrahypothalamic neural pathways in serotonin2C receptor null mutant mice.

    Directory of Open Access Journals (Sweden)

    Jennifer L Hsu

    Full Text Available The ability to entrain circadian rhythms to food availability is important for survival. Food-entrained circadian rhythms are characterized by increased locomotor activity in anticipation of food availability (food anticipatory activity. However, the molecular components and neural circuitry underlying the regulation of food anticipatory activity remain unclear. Here we show that serotonin(2C receptor (5-HT2CR null mutant mice subjected to a daytime restricted feeding schedule exhibit enhanced food anticipatory activity compared to wild-type littermates, without phenotypic differences in the impact of restricted feeding on food consumption, body weight loss, or blood glucose levels. Moreover, we show that the enhanced food anticipatory activity in 5-HT2CR null mutant mice develops independent of external light cues and persists during two days of total food deprivation, indicating that food anticipatory activity in 5-HT2CR null mutant mice reflects the locomotor output of a food-entrainable oscillator. Whereas restricted feeding induces c-fos expression to a similar extent in hypothalamic nuclei of wild-type and null mutant animals, it produces enhanced expression in the nucleus accumbens and other extrahypothalamic regions of null mutant mice relative to wild-type subjects. These data suggest that 5-HT2CRs gate food anticipatory activity through mechanisms involving extrahypothalamic neural pathways.

  17. Goal directed reaching and postural control in supine position in healthy infants

    NARCIS (Netherlands)

    Fallang, B; Saugstad, OD; Hadders-Algra, M

    2000-01-01

    The present study focussed on the development and interaction of reaching and posture in supine position in young infants. The kinematics of goal directed reaches and the concurrent ground reaction forces of the total body centre of pressure (COP) in cranial-caudal and medial-lateral direction were

  18. 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.

  19. Hyperincursive Cogitata and Incursive Cogitantes: Scholarly Discourse as a Strongly Anticipatory System

    CERN Document Server

    Leydesdorff, Loet

    2011-01-01

    Strongly anticipatory systems-that is, systems which use models of themselves for their further development-and which additionally may be able to run hyperincursive routines-that is, develop only with reference to their future states-cannot exist in res extensa, but can only be envisaged in res cogitans. One needs incursive routines in cogitantes to instantiate these systems. Unlike historical systems (with recursion), these hyper-incursive routines generate redundancies by opening horizons of other possible states. Thus, intentional systems can enrich our perceptions of the cases that have happened to occur. The perspective of hindsight codified at the above-individual level enables us furthermore to intervene technologically. The theory and computation of anticipatory systems have made these loops between supra-individual hyper-incursion, individual incursion (in instantiation), and historical recursion accessible for modeling and empirical investigation.

  20. Circadian rhythms and food anticipatory behavior in Wfs1-deficient mice

    DEFF Research Database (Denmark)

    Luuk, Hendrik; Fahrenkrug, Jan; Hannibal, Jens

    2012-01-01

    The dorsomedial hypothalamic nucleus (DMH) has been proposed as a candidate for the neural substrate of a food-entrainable oscillator. The existence of a food-entrainable oscillator in the mammalian nervous system was inferred previously from restricted feeding-induced behavioral rhythmicity...... reduced or otherwise altered food anticipatory activity. Wfs1 immunoreactivity in DMH was found almost exclusively in the compact part. Restricted feeding induced c-Fos immunoreactivity primarily in the ventral and lateral aspects of DMH and it was similar in both genotypes. Wfs1-deficiency resulted...... in significantly lower body weight and reduced wheel-running activity. Circadian rhythmicity of behavior was normal in Wfs1-deficient mice under ad libitum feeding apart from elongated free-running period in constant light. The amount of food anticipatory activity induced by restricted feeding...

  1. The interaction of anticipatory anxiety and emotional picture processing: an event-related brain potential study.

    Science.gov (United States)

    Bublatzky, Florian; Flaisch, Tobias; Stockburger, Jessica; Schmälzle, Ralf; Schupp, Harald T

    2010-07-01

    The present study examined the interaction of anticipatory anxiety and selective emotion processing. Toward this end, a rapid stream of pleasant, neutral, and unpleasant pictures was presented in alternating blocks of threat-of-shock or safety, which were signaled by colored picture frames. The main finding is that pleasant pictures elicited a sustained negative difference potential over occipital regions during threat as compared to safety periods. In contrast, unpleasant and neutral picture processing did not vary as a function of threat-of-shock. Furthermore, in both the safety and threat-of-shock conditions, emotional pictures elicited an enlarged early posterior negativity and late positive potential. These data show that the activation of the fear/anxiety network exerts valence-specific effects on affective picture processing. Pleasant stimuli mismatching the current state of anticipatory anxiety apparently draw more attentional resources.

  2. Using Narrative Approach for Anticipatory Grief Among Family Caregivers at Home

    Directory of Open Access Journals (Sweden)

    Hiroko Toyama

    2016-12-01

    Full Text Available Family caregivers of patients with terminal-stage cancer have numerous roles as caregivers, which can influence their anticipatory grief. The purpose of this study was to clarify how talking to family caregivers of patients with terminal illness using the narrative approach can influence such caregivers’ process of anticipatory grief. We conducted the narrative approach as an intervention with two family caregivers several times and qualitatively analyzed their narratives. The results indicated that these family caregivers had two primary roles—family member and caregiver—and that family caregivers felt trapped in their caregiver role. The narrative approach helped them transition into the role needed for coping with the loss.

  3. Effects of visual cues of object density on perception and anticipatory control of dexterous manipulation.

    Directory of Open Access Journals (Sweden)

    Céline Crajé

    Full Text Available Anticipatory force planning during grasping is based on visual cues about the object's physical properties and sensorimotor memories of previous actions with grasped objects. Vision can be used to estimate object mass based on the object size to identify and recall sensorimotor memories of previously manipulated objects. It is not known whether subjects can use density cues to identify the object's center of mass (CM and create compensatory moments in an anticipatory fashion during initial object lifts to prevent tilt. We asked subjects (n = 8 to estimate CM location of visually symmetric objects of uniform densities (plastic or brass, symmetric CM and non-uniform densities (mixture of plastic and brass, asymmetric CM. We then asked whether subjects can use density cues to scale fingertip forces when lifting the visually symmetric objects of uniform and non-uniform densities. Subjects were able to accurately estimate an object's center of mass based on visual density cues. When the mass distribution was uniform, subjects could scale their fingertip forces in an anticipatory fashion based on the estimation. However, despite their ability to explicitly estimate CM location when object density was non-uniform, subjects were unable to scale their fingertip forces to create a compensatory moment and prevent tilt on initial lifts. Hefting object parts in the hand before the experiment did not affect this ability. This suggests a dichotomy between the ability to accurately identify the object's CM location for objects with non-uniform density cues and the ability to utilize this information to correctly scale their fingertip forces. These results are discussed in the context of possible neural mechanisms underlying sensorimotor integration linking visual cues and anticipatory control of grasping.

  4. Effects of visual cues of object density on perception and anticipatory control of dexterous manipulation.

    Science.gov (United States)

    Crajé, Céline; Santello, Marco; Gordon, Andrew M

    2013-01-01

    Anticipatory force planning during grasping is based on visual cues about the object's physical properties and sensorimotor memories of previous actions with grasped objects. Vision can be used to estimate object mass based on the object size to identify and recall sensorimotor memories of previously manipulated objects. It is not known whether subjects can use density cues to identify the object's center of mass (CM) and create compensatory moments in an anticipatory fashion during initial object lifts to prevent tilt. We asked subjects (n = 8) to estimate CM location of visually symmetric objects of uniform densities (plastic or brass, symmetric CM) and non-uniform densities (mixture of plastic and brass, asymmetric CM). We then asked whether subjects can use density cues to scale fingertip forces when lifting the visually symmetric objects of uniform and non-uniform densities. Subjects were able to accurately estimate an object's center of mass based on visual density cues. When the mass distribution was uniform, subjects could scale their fingertip forces in an anticipatory fashion based on the estimation. However, despite their ability to explicitly estimate CM location when object density was non-uniform, subjects were unable to scale their fingertip forces to create a compensatory moment and prevent tilt on initial lifts. Hefting object parts in the hand before the experiment did not affect this ability. This suggests a dichotomy between the ability to accurately identify the object's CM location for objects with non-uniform density cues and the ability to utilize this information to correctly scale their fingertip forces. These results are discussed in the context of possible neural mechanisms underlying sensorimotor integration linking visual cues and anticipatory control of grasping.

  5. Integration between anticipatory blocking and redox signaling by the peroxiredoxin/thioredoxin/thioredoxin-reductase system.

    Science.gov (United States)

    Selvaggio, Gianluca; Coelho, Pedro M B M; Salvador, Armindo

    2014-10-01

    Cells are occasionally exposed to high H2O2 concentrations, often preceding exposure to other electrophylic compounds. Both H2O2 and these compounds can irreversibly modify protein thiols, with deleterious consequences. Induction of enzymatic defenses against those agents is too slow to avoid significant damage. Cells may solve this conundrum by reversibly "blocking" the thiols once H2O2 concentrations begin to increase. We term this mechanism "anticipatory blocking" because it acts in anticipation of irreversible damage upon detection of early signs of stress. Here we examine the design requirements for the Peroxiredoxin/Thioredoxin/Thioredoxin-Reductase/Protein-Dithiol System (PTTRDS) to effectively integrate H2O2 signaling and anticipatory blocking of protein dithiols as disulfides, and we compared them to the designs found in cells. To that effect, we developed a minimal model of the PTTRDS, and we defined a set of quantitative performance criteria that embody the requirements for (a) efficient scavenging capacity, (b) low NADPH consumption, (c) effective signal propagation, and (d) effective anticipatory blocking. We then sought the design principles (relationships among rate constants and species concentrations) that warrant fulfillment of all these criteria. Experimental data indicates that the design of the PTTRDS in human erythrocytes fulfills these principles and thus accomplishes effective integration between anticipatory blocking, antioxidant protection and redox signaling. A more general analysis suggests that the same principles hold in a wide variety of cell types and organisms. We acknowledge grants PEst-C/SAU/LA0001/2013-2014, PEst-OE/QUI/UI0612/2013, FCOMP-01-0124-FEDER-020978 (PTDC/QUI-BIQ/119657/2010) financed by FEDER through the "Programa Operacional Factores de Competitividade, COMPETE" and by national funds through "FCT, Fundação para a Ciência e a Tecnologia".

  6. 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.

  7. Microstructural analysis of negative anticipatory contrast: A reconsideration of the devaluation account.

    Science.gov (United States)

    Wright, Rebecca L; Gilmour, Gary; Dwyer, Dominic M

    2013-12-01

    An animal's appetitive behavior is not a fixed response to current stimulation but can be affected by the anticipation of future events. For example, rats regularly given access to a moderately valued solution followed by a higher value solution (e.g., 4 % sucrose → 32 % sucrose) consume less of the initial solution than in control conditions where the initial solution is not followed by a higher value solution (e.g., 4 % sucrose → 4 % sucrose). Previous analyses have suggested that this negative anticipatory contrast effect does not depend on the "expectation" of a valuable stimulus producing a functional devaluation of a currently available stimulus of lesser value. In a within-subjects anticipatory contrast procedure, this study revealed that both consumption and the mean size of licking clusters were smaller for a 4 % sucrose solution on days when it preceded 32 % sucrose than on days when 4 % preceded 4 %. Since lick cluster size typically bears a positive monotonic relationship with the concentration of palatable solutions, this reduction is indicative of a decrease in the palatability/hedonic value of the solution subject to contrast. As such, we provide direct evidence that negative anticipatory contrast does produce a functional devaluation of the solution, thus challenging prevailing theoretical assumptions.

  8. Anticipatory planning and control of grasp positions and forces for dexterous two-digit manipulation.

    Science.gov (United States)

    Fu, Qiushi; Zhang, Wei; Santello, Marco

    2010-07-07

    Dexterous object manipulation requires anticipatory control of digit positions and forces. Despite extensive studies on sensorimotor learning of digit forces, how humans learn to coordinate digit positions and forces has never been addressed. Furthermore, the functional role of anticipatory modulation of digit placement to object properties remains to be investigated. We addressed these questions by asking human subjects (12 females, 12 males) to grasp and lift an inverted T-shaped object using precision grip at constrained or self-chosen locations. The task requirement was to minimize object roll during lift. When digit position was not constrained, subjects could have implemented many equally valid digit position-force coordination patterns. However, choice of digit placement might also have resulted in large trial-to-trial variability of digit position, hence challenging the extent to which the CNS could have relied on sensorimotor memories for anticipatory control of digit forces. We hypothesized that subjects would modulate digit placement for optimal force distribution and digit forces as a function of variable digit positions. All subjects learned to minimize object roll within the first three trials, and the unconstrained device was associated with significantly smaller grip forces but larger variability of digit positions. Importantly, however, digit load force modulation compensated for position variability, thus ensuring consistent object roll minimization on each trial. This indicates that subjects learned object manipulation by integrating sensorimotor memories with sensory feedback about digit positions. These results are discussed in the context of motor equivalence and sensorimotor integration of grasp kinematics and kinetics.

  9. Anticipatory behavior in captive bottlenose dolphins (Tursiops truncatus): a preliminary study.

    Science.gov (United States)

    Jensen, Ann-Louise M; Delfour, Fabienne; Carter, Toby

    2013-01-01

    This study examined whether a group of captive dolphins displayed anticipatory behaviors before shows. In general, anticipation occurs when an event is being predicted. Anticipatory behavior is defined by Spruijt et al. as "responses elicited by rewarding stimuli that lead to and facilitate consummatory behavior (Spruijt et al., 2001, Appl Anim Behav Sci 72: 145-171)." Using behavioral recording techniques, the behaviors, breathing rates, space use, and activity levels of all dolphins was recorded both before and after shows. Analysis compared pre- and post-show data in addition to looking at gradual changes in behavior prior to show sessions. Significant changes were found in the behavior and space use prior to sessions with the dolphins decreasing their activity levels, spending more time at the surface and moving towards the starting point of a session before it took place. There was a significant increase in the vigilant behavior before sessions, indicating that the dolphins were becoming more alert towards their trainers and other activities around the pool. This result mirrors previous research with other captive species; as feeding time was approaching, the animals seemed to "wait" and look for the handlers. Any behavioral change that may be regarded as anticipatory behavior was not evidently abnormal or stereotypic in nature, and breathing rates remained stable indicating that the animals do not perceive the shows as stressful or as an aversive experience. Additionally, behavior and level of activity remained stable following the sessions.

  10. Verbal and nonverbal predictors of language-mediated anticipatory eye movements.

    Science.gov (United States)

    Rommers, Joost; Meyer, Antje S; Huettig, Falk

    2015-04-01

    During language comprehension, listeners often anticipate upcoming information. This can draw listeners' overt attention to visually presented objects before the objects are referred to. We investigated to what extent the anticipatory mechanisms involved in such language-mediated attention rely on specific verbal factors and on processes shared with other domains of cognition. Participants listened to sentences ending in a highly predictable word (e.g., "In 1969 Neil Armstrong was the first man to set foot on the moon") while viewing displays containing three unrelated distractor objects and a critical object, which was either the target object (e.g., a moon), an object with a similar shape (e.g., a tomato), or an unrelated control object (e.g., rice). Language-mediated anticipatory eye movements were observed to targets and to shape competitors. Importantly, looks to the shape competitor were systematically related to individual differences in anticipatory attention, as indexed by a spatial cueing task: Participants whose responses were most strongly facilitated by predictive arrow cues also showed the strongest effects of predictive language input on their eye movements. By contrast, looks to the target were related to individual differences in vocabulary size and verbal fluency. The results suggest that verbal and nonverbal factors contribute to different types of language-mediated eye movements. The findings are consistent with multiple-mechanism accounts of predictive language processing.

  11. Anticipatory Monitoring and Control of Complex Systems using a Fuzzy based Fusion of Support Vector Regressors

    Energy Technology Data Exchange (ETDEWEB)

    Miltiadis Alamaniotis; Vivek Agarwal

    2014-10-01

    This paper places itself in the realm of anticipatory systems and envisions monitoring and control methods being capable of making predictions over system critical parameters. Anticipatory systems allow intelligent control of complex systems by predicting their future state. In the current work, an intelligent model aimed at implementing anticipatory monitoring and control in energy industry is presented and tested. More particularly, a set of support vector regressors (SVRs) are trained using both historical and observed data. The trained SVRs are used to predict the future value of the system based on current operational system parameter. The predicted values are then inputted to a fuzzy logic based module where the values are fused to obtain a single value, i.e., final system output prediction. The methodology is tested on real turbine degradation datasets. The outcome of the approach presented in this paper highlights the superiority over single support vector regressors. In addition, it is shown that appropriate selection of fuzzy sets and fuzzy rules plays an important role in improving system performance.

  12. Anticipatory dynamics of biological systems: from molecular quantum states to evolution

    Science.gov (United States)

    Igamberdiev, Abir U.

    2015-08-01

    Living systems possess anticipatory behaviour that is based on the flexibility of internal models generated by the system's embedded description. The idea was suggested by Aristotle and is explicitly introduced to theoretical biology by Rosen. The possibility of holding the embedded internal model is grounded in the principle of stable non-equilibrium (Bauer). From the quantum mechanical view, this principle aims to minimize energy dissipation in expense of long relaxation times. The ideas of stable non-equilibrium were developed by Liberman who viewed living systems as subdivided into the quantum regulator and the molecular computer supporting coherence of the regulator's internal quantum state. The computational power of the cell molecular computer is based on the possibility of molecular rearrangements according to molecular addresses. In evolution, the anticipatory strategies are realized both as a precession of phylogenesis by ontogenesis (Berg) and as the anticipatory search of genetic fixation of adaptive changes that incorporates them into the internal model of genetic system. We discuss how the fundamental ideas of anticipation can be introduced into the basic foundations of theoretical biology.

  13. Spinal mechanisms may provide a combination of intermittent and continuous control of human posture: predictions from a biologically based neuromusculoskeletal model.

    Directory of Open Access Journals (Sweden)

    Leonardo Abdala Elias

    2014-11-01

    Full Text Available Several models have been employed to study human postural control during upright quiet stance. Most have adopted an inverted pendulum approximation to the standing human and theoretical models to account for the neural feedback necessary to keep balance. The present study adds to the previous efforts in focusing more closely on modelling the physiological mechanisms of important elements associated with the control of human posture. This paper studies neuromuscular mechanisms behind upright stance control by means of a biologically based large-scale neuromusculoskeletal (NMS model. It encompasses: i conductance-based spinal neuron models (motor neurons and interneurons; ii muscle proprioceptor models (spindle and Golgi tendon organ providing sensory afferent feedback; iii Hill-type muscle models of the leg plantar and dorsiflexors; and iv an inverted pendulum model for the body biomechanics during upright stance. The motor neuron pools are driven by stochastic spike trains. Simulation results showed that the neuromechanical outputs generated by the NMS model resemble experimental data from subjects standing on a stable surface. Interesting findings were that: i an intermittent pattern of muscle activation emerged from this posture control model for two of the leg muscles (Medial and Lateral Gastrocnemius; and ii the Soleus muscle was mostly activated in a continuous manner. These results suggest that the spinal cord anatomy and neurophysiology (e.g., motor unit types, synaptic connectivities, ordered recruitment, along with the modulation of afferent activity, may account for the mixture of intermittent and continuous control that has been a subject of debate in recent studies on postural control. Another finding was the occurrence of the so-called "paradoxical" behaviour of muscle fibre lengths as a function of postural sway. The simulations confirmed previous conjectures that reciprocal inhibition is possibly contributing to this effect, but

  14. Spinal mechanisms may provide a combination of intermittent and continuous control of human posture: predictions from a biologically based neuromusculoskeletal model.

    Science.gov (United States)

    Elias, Leonardo Abdala; Watanabe, Renato Naville; Kohn, André Fabio

    2014-11-01

    Several models have been employed to study human postural control during upright quiet stance. Most have adopted an inverted pendulum approximation to the standing human and theoretical models to account for the neural feedback necessary to keep balance. The present study adds to the previous efforts in focusing more closely on modelling the physiological mechanisms of important elements associated with the control of human posture. This paper studies neuromuscular mechanisms behind upright stance control by means of a biologically based large-scale neuromusculoskeletal (NMS) model. It encompasses: i) conductance-based spinal neuron models (motor neurons and interneurons); ii) muscle proprioceptor models (spindle and Golgi tendon organ) providing sensory afferent feedback; iii) Hill-type muscle models of the leg plantar and dorsiflexors; and iv) an inverted pendulum model for the body biomechanics during upright stance. The motor neuron pools are driven by stochastic spike trains. Simulation results showed that the neuromechanical outputs generated by the NMS model resemble experimental data from subjects standing on a stable surface. Interesting findings were that: i) an intermittent pattern of muscle activation emerged from this posture control model for two of the leg muscles (Medial and Lateral Gastrocnemius); and ii) the Soleus muscle was mostly activated in a continuous manner. These results suggest that the spinal cord anatomy and neurophysiology (e.g., motor unit types, synaptic connectivities, ordered recruitment), along with the modulation of afferent activity, may account for the mixture of intermittent and continuous control that has been a subject of debate in recent studies on postural control. Another finding was the occurrence of the so-called "paradoxical" behaviour of muscle fibre lengths as a function of postural sway. The simulations confirmed previous conjectures that reciprocal inhibition is possibly contributing to this effect, but on the

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Increasing speed to improve arm movement and standing postural control in Parkinson's disease patients when catching virtual moving balls.

    Science.gov (United States)

    Su, Kuei-Jung; Hwang, Wen-Juh; Wu, Ching-yi; Fang, Jing-Jing; Leong, Iat-Fai; Ma, Hui-Ing

    2014-01-01

    Research has shown that moving targets help Parkinson's disease (PD) patients improve their arm movement while sitting. We examined whether increasing the speed of a moving ball would also improve standing postural control in PD patients during a virtual reality (VR) ball-catching task. Twenty-one PD patients and 21 controls bilaterally reached to catch slow-moving and then fast-moving virtual balls while standing. A projection-based VR system connected to a motion-tracking system and a force platform was used. Dependent measures included the kinematics of arm movement (movement time, peak velocity), duration of anticipatory postural adjustments (APA), and center of pressure (COP) movement (movement time, maximum amplitude, and average velocity). When catching a fast ball, both PD and control groups made arm movements with shorter movement time and higher peak velocity, longer APA, as well as COP movements with shorter movement time and smaller amplitude than when catching a slow ball. The change in performance from slow- to fast-ball conditions was not different between the PD and control groups. The results suggest that raising the speed of virtual moving targets should increase the speed of arm and COP movements for PD patients. Therapists, however, should also be aware that a fast virtual moving target causes the patient to confine the COP excursion to a smaller amplitude. Future research should examine the effect of other task parameters (e.g., target distance, direction) on COP movement and examine the long-term effect of VR training.

  1. 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

  2. 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...

  3. 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...

  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. 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....

  6. 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.

  7. Time-of-day effects on postural control and attentional capacities in children.

    Science.gov (United States)

    Baccouch, Rym; Zarrouk, Nidhal; Chtourou, Hamdi; Rebai, Haithem; Sahli, Sonia

    2015-04-01

    The present study aimed to examine the effect of time-of-day on postural control, body temperature, and attentional capacities in 5-6 year old children. Twelve male children (5-6-year-old) were asked to maintain an upright bipedal stance on a force platform with eyes open (EO) and eyes closed (EC) at 07:00, 10:00, 14:00, and 18:00 h. Postural control was evaluated by center of pressure (CoP) surface area (CoPArea), CoP mean velocity (CoPVm), length of the CoP displacement as a function of the surface (LFS) ratio and Romberg's index (RI). Oral temperature and the simple reaction time were also recorded at the beginning of each test session. The one way ANOVA (4 time-of-day) showed significant time-of-day effects on CoPArea (pChildren's postural control was lower at 07:00 h and at 14:00 h in comparison with 10:00 h and 18:00 h. Likewise, the reaction time was significantly (pchildren's postural control fluctuates during the daytime (i.e., better postural control at 10:00 h and at 18:00 h) with a diurnal rhythm close to that of body temperature and attentional capacities. Therefore, the evaluation of changes in postural control of 5-6-year-old children using force plate measures is recommended in the middle morning or the late afternoon to avoid the post-awakening and the post-prandial phases.

  8. Effects of Shift Work on the Postural and Psychomotor Performance of Night Workers.

    Directory of Open Access Journals (Sweden)

    Fernanda Veruska Narciso

    Full Text Available The purpose of the study was to investigate the effects of shift work on the psychomotor and postural performance of night workers. The study included 20 polysomnography technicians working schedule of 12-h night shift by 36-h off. On the first day of protocol, the body mass and height were measured, and an actigraph was placed on the wrist of each participant. On the second day of protocol, sleepiness by Karolinska Sleepiness Scale, postural control by force platform (30 seconds and psychomotor performance by Psychomotor Vigilance Task (10 minutes were measured before and after 12-h night work. Results showed that after 12-h night work, sleepiness increased by 59% (p<0.001, postural control variables increased by 9% (p = 0.048, and 14% (p = 0.006. Mean reaction time, and the number of lapses of attention increased by 13% (p = 0.006 and 425% (p = 0.015, respectively, but the mean reciprocal reaction time decreased by 7%. In addition, there were correlations between sleepiness and postural control variables with opened eyes (r = 0.616, 95% confidence interval [CI] = 0.361-0.815; r = 0.538; 95% CI = 0.280-0.748 and closed eyes (r = 0.557; 95% CI = 0.304-0.764, r = 0497; 95% CI = 0.325-0.715 and a pronounced effect of sleepiness on postural sway (R2 = 0.393; 95% CI = 0.001-0.03. Therefore, 12-h night work system and sleepiness showed a negative impact in postural and psychomotor vigilance performance of night workers. As unexpected, the force platform was feasibility to detect sleepiness in this population, underscoring the possibility of using this method in the workplace to prevent occupational injuries and accidents.

  9. 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.

  10. Postural Control in Man: The Phylogenetic Perspective

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Stress appraisals and cellular aging: a key role for anticipatory threat in the relationship between psychological stress and telomere length.

    Science.gov (United States)

    O'Donovan, Aoife; Tomiyama, A Janet; Lin, Jue; Puterman, Eli; Adler, Nancy E; Kemeny, Margaret; Wolkowitz, Owen M; Blackburn, Elizabeth H; Epel, Elissa S

    2012-05-01

    Chronic psychological stress is a risk factor for multiple diseases of aging. Accelerated cellular aging as indexed by short telomere length has emerged as a potential common biological mechanism linking various forms of psychological stress and diseases of aging. Stress appraisals determine the degree and type of biological stress responses and altered stress appraisals may be a common psychological mechanism linking psychological stress and diseases of aging. However, no previous studies have examined the relationship between stress appraisals and telomere length. We exposed chronically stressed female caregivers and non-caregiving controls (N=50; M age=62.14±6.10) to a standardized acute laboratory stressor and measured their anticipatory and retrospective threat and challenge appraisals of the stressor. We hypothesized that threat and challenge appraisals would be associated with shorter and longer telomere length respectively, and that chronic caregiving stress would influence telomere length through altered stress appraisals. Higher anticipatory threat appraisals were associated with shorter age-adjusted telomere length (β=-.32, p=.03), but challenge appraisals and retrospective threat appraisals showed no independent association with telomere length. Caregivers reported significantly higher anticipatory (β=-.36, p=.006) and retrospective (β=-.29, p=.03) threat appraisals than controls, but similar challenge appraisals. Although there was no significant main effect of caregiver status on telomere length, caregiving had a significant indirect effect on telomere length through anticipatory threat appraisals. Exaggerated anticipatory threat appraisals may be a common and modifiable psychological mechanism of psychological stress effects on cellular aging.

  13. Consummatory and anticipatory anhedonia in schizophrenia: stability, and associations with emotional distress and social function over six months.

    Science.gov (United States)

    Buck, Benjamin; Lysaker, Paul H

    2013-01-30

    Recent work has suggested that anhedonia in schizophrenia can be understood as involving two separate constructs: deficits in anticipatory and consummatory pleasure. Little is known about the relative stability of these different constructs and their links with clinical features and social function over time. To examine these questions, 51 participants with a diagnosis of schizophrenia or schizoaffective disorder in a non-acute phase of illness were administered the Temporal Experience of Pleasure Scale, the Positive and Negative Syndrome Scale, and Quality of Life Scale at two time points six months apart. Results revealed that baseline scores of both anticipatory and consummatory pleasure were significantly correlated with follow-up scores six months later, suggesting each construct is stable in the short term. The association of anticipatory pleasure at baseline and six months was significantly higher than the relationship between consummatory pleasure at baseline and at six months. Anticipatory pleasure predicted concurrent and prospective levels of positive symptoms, emotional discomfort, and interpersonal function, but not emotion recognition. Consummatory pleasure predicted only concurrent positive symptoms. The link of baseline anticipatory pleasure with emotional discomfort at six months persisted even after controlling for baseline emotional discomfort. Implications for the measurement and conceptualization of anhedonia in schizophrenia are discussed.

  14. Slipping during side-step cutting: anticipatory effects and familiarization.

    Science.gov (United States)

    Oliveira, Anderson Souza Castelo; Silva, Priscila Brito; Lund, Morten Enemark; Farina, Dario; Kersting, Uwe Gustav

    2014-04-01

    The aim of the present study was to verify whether the expectation of perturbations while performing side-step cutting manoeuvres influences lower limb EMG activity, heel kinematics and ground reaction forces. Eighteen healthy men performed two sets of 90° side-step cutting manoeuvres. In the first set, 10 unperturbed trials (Base) were performed while stepping over a moveable force platform. In the second set, subjects were informed about the random possibility of perturbations to balance throughout 32 trials, of which eight were perturbed (Pert, 10cm translation triggered at initial contact), and the others were "catch" trials (Catch). Center of mass velocity (CoMVEL), heel acceleration (HAC), ground reaction forces (GRF) and surface electromyography (EMG) from lower limb and trunk muscles were recorded for each trial. Surface EMG was analyzed prior to initial contact (PRE), during load acceptance (LA) and propulsion (PRP) periods of the stance phase. In addition, hamstrings-quadriceps co-contraction ratios (CCR) were calculated for these time-windows. The results showed no changes in CoMVEL, HAC, peak GRF and surface EMG PRE among conditions. However, during LA, there were increases in tibialis anterior EMG (30-50%) concomitant to reduced EMG for quadriceps muscles, gluteus and rectus abdominis for Catch and Pert conditions (15-40%). In addition, quadriceps EMG was still reduced during PRP (pmodulation of muscle activity towards anticipating potential instability in the lower limb joints and assure safety to complete the task.

  15. Classically conditioned postural reflex in cerebellar patients.

    Science.gov (United States)

    Kolb, F P; Lachauer, S; Maschke, M; Timmann, D

    2004-09-01

    The aim of the current study was to compare postural responses to repetitive platform-evoked perturbations in cerebellar patients with those of healthy subjects using a classical conditioning paradigm. The perturbations consisted of tilting of the platform (unconditioned stimulus: US) at random time intervals, preceded by an auditory signal that represented the conditioning stimulus (CS). Physiological reactions were recorded biomechanically by measuring the vertical ground forces, yielding the center of vertical pressure (CVP), and electrophysiologically by EMG measurements of the main muscle groups of both legs. The recording session consisted of a control section with US-alone trials, a testing section with paired stimuli and a brief final section with US-alone trials. Healthy control subjects were divided into those establishing conditioned responses (CR) in all muscles tested (strategy I) and those with CR in the gastrocnemius muscles only (strategy II), suggesting an associative motor-related process is involved. Patients with a diffuse, non-localized disease were almost unable to establish CR. This was also true for a patient with a focal surgical lesion with no CR on the affected side but who, simultaneously, showed an essentially normal CR incidence on the intact side. During US-alone trials healthy controls exhibited a remarkable decay of the UR amplitude due to a non-associative motor-related process such as habituation. The decay was most prominent in the paired trials section. In contrast, patients showed no significant differences in the UR amplitude throughout the entire recording session. Analysis of the CVP supported the electrophysiological findings, showing CR in the controls only. The differences between the responses of control subjects and those of the cerebellar patients imply strongly that the cerebellum is involved critically in controlling associative and non-associative motor-related processes.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Reliability of photographic posture analysis of adolescents.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Visual Cues of Object Properties Differentially Affect Anticipatory Planning of Digit Forces and Placement.

    Science.gov (United States)

    Lee-Miller, Trevor; Marneweck, Michelle; Santello, Marco; Gordon, Andrew M

    2016-01-01

    Studies on anticipatory planning of object manipulation showed initial task failure (i.e., object roll) when visual object shape cues are incongruent with other visual cues, such as weight distribution/density (e.g., symmetrically shaped object with an asymmetrical density). This suggests that shape cues override density cues. However, these studies typically only measured forces, with digit placement constrained. Recent evidence suggests that when digit placement is unconstrained, subjects modulate digit forces and placement. Thus, unconstrained digit placement might be modulated on initial trials (since it is an explicit process), but not forces (since it is an implicit process). We tested whether shape and density cues would differentially influence anticipatory planning of digit placement and forces during initial trials of a two-digit object manipulation task. Furthermore, we tested whether shape cues would override density cues when cues are incongruent. Subjects grasped and lifted an object with the aim of preventing roll. In Experiment 1, the object was symmetrically shaped, but with asymmetrical density (incongruent cues). In Experiment 2, the object was asymmetrical in shape and density (congruent cues). In Experiment 3, the object was asymmetrically shaped, but with symmetrical density (incongruent cues). Results showed differential modulation of digit placement and forces (modulation of load force but not placement), but only when shape and density cues were congruent. When shape and density cues were incongruent, we found collinear digit placement and symmetrical force sharing. This suggests that congruent and incongruent shape and density cues differentially influence anticipatory planning of digit forces and placement. Furthermore, shape cues do not always override density cues. A continuum of visual cues, such as those alluding to shape and density, need to be integrated.

  20. Before and Beyond Anticipatory Intelligence: Assessing the Potential for Crowdsourcing and Intelligence Studies

    Directory of Open Access Journals (Sweden)

    Alexander Halman

    2015-10-01

    Full Text Available Crowdsourcing is a new tool for businesses, academics, and now intelligence analysts. Enabled by recent technology, crowdsourcing allows researchers to harness the wisdom of crowds and provide recommendations and insight into complex problems. This paper examines the potential benefits and limitations of crowdsourcing for intelligence analysis and the intelligence community beyond its primary use: anticipatory intelligence. The author constructs a model and compares it to existing crowdsourcing theories in business, information science, and public policy. Finally, he offers advice for intelligence analysis and public policy.

  1. Filling in the gaps: Anticipatory control of eye movements in chronic mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Mithun Diwakar

    2015-01-01

    Full Text Available A barrier in the diagnosis of mild traumatic brain injury (mTBI stems from the lack of measures that are adequately sensitive in detecting mild head injuries. MRI and CT are typically negative in mTBI patients with persistent symptoms of post-concussive syndrome (PCS, and characteristic difficulties in sustaining attention often go undetected on neuropsychological testing, which can be insensitive to momentary lapses in concentration. Conversely, visual tracking strongly depends on sustained attention over time and is impaired in chronic mTBI patients, especially when tracking an occluded target. This finding suggests deficient internal anticipatory control in mTBI, the neural underpinnings of which are poorly understood. The present study investigated the neuronal bases for deficient anticipatory control during visual tracking in 25 chronic mTBI patients with persistent PCS symptoms and 25 healthy control subjects. The task was performed while undergoing magnetoencephalography (MEG, which allowed us to examine whether neural dysfunction associated with anticipatory control deficits was due to altered alpha, beta, and/or gamma activity. Neuropsychological examinations characterized cognition in both groups. During MEG recordings, subjects tracked a predictably moving target that was either continuously visible or randomly occluded (gap condition. MEG source-imaging analyses tested for group differences in alpha, beta, and gamma frequency bands. The results showed executive functioning, information processing speed, and verbal memory deficits in the mTBI group. Visual tracking was impaired in the mTBI group only in the gap condition. Patients showed greater error than controls before and during target occlusion, and were slower to resynchronize with the target when it reappeared. Impaired tracking concurred with abnormal beta activity, which was suppressed in the parietal cortex, especially the right hemisphere, and enhanced in left caudate and

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

    Science.gov (United States)

    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.

  3. The importance of recognizing postural pseudoanemia.

    Science.gov (United States)

    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.

  4. Postural sway following cryotherapy in healthy adults.

    Science.gov (United States)

    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.

  5. 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)

  6. 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.

  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. 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.

  9. 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...

  10. 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.

  11. 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...

  12. 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

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. Too much anticipation? Large anticipatory adjustments of grasping movements to minimal object manipulations.

    Science.gov (United States)

    Herbort, Oliver

    2015-08-01

    When humans grasp objects, the grasps foreshadow the intended object manipulation. It has been suggested that grasps are selected that lead to medial arm postures, which facilitate movement speed and precision, during critical phases of the object manipulation. In Experiment 1, it has been tested whether grasp selections lead to medial postures during rotations of a dial. Participants twisted their arms considerably before grasping the dial, even when the upcoming dial rotation was minimal (5°). Participants neither assumed a medial posture at any point during a short rotation, nor did they assume any of the postures involved in short rotations in the opposite direction. Thus, grasp selections did not necessarily lead to specific postures at any point of the object manipulation. Experiment 2 examined the effect of various grasps on the speed of dial rotations. A medial initial grasp resulted in the fastest dial rotations for most rotation angles. Spontaneously selected grasps were more excursed than necessary to maximize dial rotation speed. This apparent overshot might be explained by participants' sensitive to the variability of their grasps and is in line with the assumption that grasps facilitate control over the grasped object.

  18. Delayed Anticipatory Spoken Language Processing in Adults with Dyslexia—Evidence from Eye-tracking.

    Science.gov (United States)

    Huettig, Falk; Brouwer, Susanne

    2015-05-01

    It is now well established that anticipation of upcoming input is a key characteristic of spoken language comprehension. It has also frequently been observed that literacy influences spoken language processing. Here, we investigated whether anticipatory spoken language processing is related to individuals' word reading abilities. Dutch adults with dyslexia and a control group participated in two eye-tracking experiments. Experiment 1 was conducted to assess whether adults with dyslexia show the typical language-mediated eye gaze patterns. Eye movements of both adults with and without dyslexia closely replicated earlier research: spoken language is used to direct attention to relevant objects in the environment in a closely time-locked manner. In Experiment 2, participants received instructions (e.g., 'Kijk naar de(COM) afgebeelde piano(COM)', look at the displayed piano) while viewing four objects. Articles (Dutch 'het' or 'de') were gender marked such that the article agreed in gender only with the target, and thus, participants could use gender information from the article to predict the target object. The adults with dyslexia anticipated the target objects but much later than the controls. Moreover, participants' word reading scores correlated positively with their anticipatory eye movements. We conclude by discussing the mechanisms by which reading abilities may influence predictive language processing.

  19. Anticipatory activity in rat medial prefrontal cortex during a working memory task

    Institute of Scientific and Technical Information of China (English)

    Wenwen Bai; Tiaotiao Liu; Hu Yi; Shuangyan Li; Xin Tian

    2012-01-01

    Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role.This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event.Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task.Then a 16-channel microelectrode array was implanted in the prefrontal cortex.After recovery,neuronal population activity was recorded during the task,using the Cerebus data-acquisition system.Spatio-temporal trains of action potentials were obtained from the original neuronal population signals.Results During the Y-maze working memory task,some neurons showed significantly increased firing rates and evident neuronal ensemble activity.Moreover,the anticipatory activity was associated with the delayed alternate choice of the upcoming movement.In correct trials,the averaged pre-event firing rate (10.86 ± 1.82 spikes/bin) was higher than the post-event rate (8.17 ± 1.15 spikes/bin) (P <0.05).However,in incorrect trials,the rates did not differ.Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.

  20. Circadian rhythms and food anticipatory behavior in Wfs1-deficient mice.

    Science.gov (United States)

    Luuk, Hendrik; Fahrenkrug, Jan; Hannibal, Jens

    2012-08-10

    The dorsomedial hypothalamic nucleus (DMH) has been proposed as a candidate for the neural substrate of a food-entrainable oscillator. The existence of a food-entrainable oscillator in the mammalian nervous system was inferred previously from restricted feeding-induced behavioral rhythmicity in rodents with suprachiasmatic nucleus lesions. In the present study, we have characterized the circadian rhythmicity of behavior in Wfs1-deficient mice during ad libitum and restricted feeding. Based on the expression of Wfs1 protein in the DMH it was hypothesized that Wfs1-deficient mice will display reduced or otherwise altered food anticipatory activity. Wfs1 immunoreactivity in DMH was found almost exclusively in the compact part. Restricted feeding induced c-Fos immunoreactivity primarily in the ventral and lateral aspects of DMH and it was similar in both genotypes. Wfs1-deficiency resulted in significantly lower body weight and reduced wheel-running activity. Circadian rhythmicity of behavior was normal in Wfs1-deficient mice under ad libitum feeding apart from elongated free-running period in constant light. The amount of food anticipatory activity induced by restricted feeding was not significantly different between the genotypes. Present results indicate that the effects of Wfs1-deficiency on behavioral rhythmicity are subtle suggesting that Wfs1 is not a major player in the neural networks responsible for circadian rhythmicity of behavior.

  1. Dopaminergic regulation of circadian food anticipatory activity rhythms in the rat.

    Directory of Open Access Journals (Sweden)

    Andrea N Smit

    Full Text Available Circadian activity rhythms are jointly controlled by a master pacemaker in the hypothalamic suprachiasmatic nuclei (SCN and by food-entrainable circadian oscillators (FEOs located elsewhere. The SCN mediates synchrony to daily light-dark cycles, whereas FEOs generate activity rhythms synchronized with regular daily mealtimes. The location of FEOs generating food anticipation rhythms, and the pathways that entrain these FEOs, remain to be clarified. To gain insight into entrainment pathways, we developed a protocol for measuring phase shifts of anticipatory activity rhythms in response to pharmacological probes. We used this protocol to examine a role for dopamine signaling in the timing of circadian food anticipation. To generate a stable food anticipation rhythm, rats were fed 3h/day beginning 6-h after lights-on or in constant light for at least 3 weeks. Rats then received the D2 agonist quinpirole (1 mg/kg IP alone or after pretreatment with the dopamine synthesis inhibitor α-methylparatyrosine (AMPT. By comparison with vehicle injections, quinpirole administered 1-h before lights-off (19h before mealtime induced a phase delay of activity onset prior to the next meal. Delay shifts were larger in rats pretreated with AMPT, and smaller following quinpirole administered 4-h after lights-on. A significant shift was not observed in response to the D1 agonist SKF81297. These results provide evidence that signaling at D2 receptors is involved in phase control of FEOs responsible for circadian food anticipatory rhythms in rats.

  2. Relationship between anticipatory socialization experiences and first-year veterinary students' career interests.

    Science.gov (United States)

    Kedrowicz, April A; Fish, Richard E; Hammond, Sarah

    2015-01-01

    The purpose of this project was to explore first-year veterinary students' anticipatory socialization-life, education, and social experiences that assist in preparation for professional occupations-and determine what relationship exists between those experiences and career interests. Seventy-three first-year veterinary students enrolled in the Careers in Veterinary Medicine course completed the Veterinary Careers survey. Results show that students' anticipatory vocational socialization experiences are significantly related to their stated career interests. The career interests with the highest percentage of students expressing "a great deal of interest" included specialty private practice (37%), research and teaching in an academic setting (33%), and international veterinary medicine (31%). The career interests with the highest percentage of students expressing "no interest at all" included the military (50%), equine private practice (42%), and the pharmaceutical industry (41%). Less than half of the students (42%) stated that they reconsidered their career path after the first semester of veterinary school, but the majority (87%) developed a better understanding of how to pursue a nontraditional career path should they choose to do so.

  3. 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...

  4. 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.

  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. 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.

  7. 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.

  8. 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…

  9. Effects of age and non-oropharyngeal proprioceptive and exteroceptive sensation on the magnitude of anticipatory mouth opening during eating.

    Science.gov (United States)

    Shune, S E; Moon, J B

    2016-09-01

    To best prevent and treat eating/swallowing problems, it is essential to understand how components of oral physiology contribute to the preservation and/or degradation of eating/swallowing in healthy ageing. Anticipatory, pre-swallow motor movements may be critical to safe and efficient eating/swallowing, particularly for older adults. However, the nature of these responses is relatively unknown. This study compared the magnitude of anticipatory mouth opening during eating in healthy older (aged 70-85) and younger (aged 18-30) adults under four eating conditions: typical self-feeding, typical assisted feeding (being fed by a research assistant resulting in proprioceptive loss), sensory loss self-feeding (wearing blindfold/headphones resulting in exteroceptive loss) and sensory loss assisted feeding (proprioceptive and exteroceptive loss). Older adults opened their mouths wider than younger adults in anticipation of food intake under both typical and most non-oropharyngeal sensory loss conditions. Further, the loss of proprioceptive and exteroceptive cues resulted in decreased anticipatory mouth opening for all participants. Greater mouth opening in older adults may be a protective compensation, contributing to the preservation of function associated with healthy ageing. Our finding that the loss of non-oropharyngeal sensory cues resulted in decreased anticipatory mouth opening highlights how important proprioception, vision, and hearing are in pre-swallow behaviour. Age- and disease-related changes in vision, hearing, and the ability to self-feed may reduce the effectiveness of these pre-swallow strategies.

  10. 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.

  11. Feet distance and static postural balance: implication on the role of natural stance.

    Science.gov (United States)

    Kim, Ji-Won; Kwon, Yuri; Jeon, Hyung-Min; Bang, Min-Jung; Jun, Jae-Hoon; Eom, Gwang-Moon; Lim, Do-Hyung

    2014-01-01

    The purpose of this study was to investigate 1) the effect of feet distance on static postural balance and 2) the location of natural feet distance and its possible role in the relationship of feet distance and postural balance. Static balance tests were performed on a force platform for 100 s with six different feet distances (0, 5, 10, 15, 20, 25 cm). Measures of postural balance included mean amplitude of horizontal ground reaction force (GRF) as well as the mean distance and velocity of the center of pressure (COP). All measures were discomposed into anterioposterior and mediolateral directions. ANOVA and post-hoc comparison were performed for all measures with feet distance as an independent factor. Also measured was the feet distance at the natural stance preferred by each subject. All measures significantly varied with feet distance (ppostural control) in an inverted pendulum model with the horizontal GRF ignored. On the other hand, horizontal GRF is the direct cause of horizontal acceleration of a center of mass. The present result on horizontal GRF shows that the effort of postural control is minimized around the feet distance of natural standing and implies why the natural stance is preferred.

  12. 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.

  13. Forearm posture and mobility in quadrupedal dinosaurs.

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    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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Differences in Anticipatory Behaviour between Rats (Rattus norvegicus Housed in Standard versus Semi-Naturalistic Laboratory Environments.

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    I Joanna Makowska

    Full Text Available Laboratory rats are usually kept in relatively small cages, but research has shown that they prefer larger and more complex environments. The physiological, neurological and health effects of standard laboratory housing are well established, but fewer studies have addressed the sustained emotional impact of a standard cage environment. One method of assessing affective states in animals is to look at the animals' anticipatory behaviour between the presentation of a cue signalling the arrival of a reward and the arrival of that reward. The primary aim of this study was to use anticipatory behaviour to assess the affective state experienced by female rats a reared and housed long-term in a standard laboratory cage versus a semi-naturalistic environment, and b before and after treatment with an antidepressant or an anxiolytic. A secondary aim was to add to the literature on anticipatory behaviour by describing and comparing the frequency and duration of individual elements of anticipatory behaviour displayed by rats reared in these two systems. In all experiments, total behavioural frequency was higher in standard-housed rats compared to rats from the semi-naturalistic condition, suggesting that standard-housed rats were more sensitive to rewards and experiencing poorer welfare than rats reared in the semi-naturalistic environment. What rats did in anticipation of the reward also differed between housing treatments, with standard-housed rats mostly rearing and rats from the semi-naturalistic condition mostly sitting facing the direction of the upcoming treat. Drug interventions had no effect on the quantity or form of anticipatory behaviour, suggesting that the poorer welfare experienced by standard-housed rats was not analogous to depression or anxiety, or alternatively that the drug interventions were ineffective. This study adds to mounting evidence that standard laboratory housing for rats compromises rat welfare, and provides further

  2. 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.

  3. Anticipatory modulation of digit placement for grasp control is affected by Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Jamie R Lukos

    Full Text Available BACKGROUND: Successful object manipulation relies on the ability to form and retrieve sensorimotor memories of digit forces and positions used in previous object lifts. Past studies of patients affected by Parkinson's disease (PD have revealed that the basal ganglia play a crucial role in the acquisition and/or retrieval of sensorimotor memories for grasp control. Whereas it is known that PD impairs anticipatory control of digit forces during grasp, learning deficits associated with the planning of digit placement have yet to be explored. This question is motivated by recent work in healthy subjects revealing that anticipatory control of digit placement plays a crucial role for successful manipulation. METHODOLOGY/PRINCIPAL FINDINGS: We asked ten PD patients off medication and ten age-matched controls to reach, grasp and lift an object whose center of mass (CM was on the left, right or center. The only task requirement was to minimize object roll during lift. The CM remained the same across consecutive trials (blocked condition or was altered from trial to trial (random condition. We hypothesized that impairment of the basal ganglia-thalamo-cortical circuits in PD patients would reduce their ability to anticipate digit placement appropriate to the CM location. Consequently, we predicted that PD patients would exhibit similar digit placement in the blocked vs. random conditions and produce larger peak object rolls than that of control subjects. In the blocked condition, PD patients exhibited significantly weaker modulation of fingertip contact points to CM location and larger object roll than controls (p<0.05 and p<0.01, respectively. Nevertheless, both controls and PD patients minimized object roll more in the blocked than in the random condition (p<0.01. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that, even though PD patients may have a residual ability of anticipatory control of digit contact points and forces, they fail to implement a

  4. Anticipatory pragmatics

    DEFF Research Database (Denmark)

    Mey, J. L.

    2012-01-01

    , and as such was seen as part of the social struggle. Recent work by Sachiko Ide and her co-workers has broadened this notion to comprise emancipation from all sorts of linguistic bondage. With regard to pragmatics, 'emancipatory' denotes a discipline that does not obey the usual circumscription of linguistic work...

  5. Anticipatory and Reactive Response to Falls: Muscle Synergy Activation of Forearm Muscles.

    Science.gov (United States)

    Couzens, Greg; Kerr, Graham

    2015-10-01

    We investigated the surface electromyogram response of six forearm muscles to falls onto the outstretched hand. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, abductor pollicis longus, flexor carpi radialis and flexor carpi ulnaris muscles were sampled from eight volunteers who underwent ten self-initiated falls. All muscles initiated prior to impact. Co-contraction is the most obvious surface electromyogram feature. The predominant response is in the radial deviators. The surface electromyogram timing we recorded would appear to be a complex anticipatory response to falling modified by the effect on the forearm muscles following impact. The mitigation of the force of impact is probably more importantly through shoulder abduction and extension and elbow flexion rather than action of the forearm muscles.

  6. Clinical audit on documentation of anticipatory "Not for Resuscitation" orders in a tertiary australian teaching hospital

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    Naveen Sulakshan Salins

    2011-01-01

    Full Text Available Aim: The purpose of this clinical audit was to determine how accurately documentation of anticipatory Not for Resuscitation (NFR orders takes place in a major metropolitan teaching hospital of Australia. Materials and Methods: Retrospective hospital-based study. Independent case reviewers using a questionnaire designed to study NFR documentation reviewed documentation of NFR in 88 case records. Results: Prognosis was documented in only 40% of cases and palliative care was offered to two-third of patients with documented NFR. There was no documentation of the cardiopulmonary resuscitation (CPR process or outcomes of CPR in most of the cases. Only in less than 50% of cases studied there was documented evidence to suggest that the reason for NFR documentation was consistent with patient′s choices. Conclusion: Good discussion, unambiguous documentation and clinical supervision of NFR order ensure dignified and quality care to the dying.

  7. Locked into gambling: anticipatory regret as a motivator for playing the National Lottery.

    Science.gov (United States)

    Wolfson, Sandy; Briggs, Pam

    2002-01-01

    Four hundred and eighty-five people were asked about their intentions to play the National Lottery in England a week prior to the introduction of a new midweek draw. We predicted that those people who played the Saturday game with a regular set of numbers would be more inclined to play the new midweek game than those who had not established a routine of using the same set of numbers. We further predicted that their motivation to play would derive from a feeling of 'anticipatory regret'--a sense that they would find it intolerable to discover their regular numbers had been drawn when they hadn't purchased a ticket. Results supported both of these predictions, and an interpretation of the data is given in terms of the circumstances most likely to trigger such counterfactual reasoning.

  8. Rethinking food anticipatory activity in the activity-based anorexia rat model.

    Science.gov (United States)

    Wu, Hemmings; van Kuyck, Kris; Tambuyzer, Tim; Luyten, Laura; Aerts, Jean-Marie; Nuttin, Bart

    2014-01-29

    When a rat is on a limited fixed-time food schedule with full access to a running wheel (activity-based anorexia model, ABA), its activity level will increase hours prior to the feeding period. This activity, called food-anticipatory activity (FAA), is a hypothesized parallel to the hyperactivity symptom in human anorexia nervosa. To investigate in depth the characteristics of FAA, we retrospectively analyzed the level of FAA and activities during other periods in ABA rats. To our surprise, rats with the most body weight loss have the lowest level of FAA, which contradicts the previously established link between FAA and the severity of ABA symptoms. On the contrary, our study shows that postprandial activities are more directly related to weight loss. We conclude that FAA alone may not be sufficient to reflect model severity, and activities during other periods may be of potential value in studies using ABA model.

  9. New development in Anticipatory Agent System used for Power Management in Smart Home Simulator

    Directory of Open Access Journals (Sweden)

    Ahmed Elmahalawy

    2012-03-01

    Full Text Available In recent years, there is a global evolution in the way energy is generated and consumed due to climate change, energy independence and the impending decay of fossil fuels. It has seen a rise of interest in the deployment of multi agent systems in energy domains that inherently have uncertain and dynamic environments with limited resources. In such domains, the key challenge is to minimize the energy consumption while satisfying the comfort level of occupants in the buildings under uncertainty (regarding agent negotiation actions. This paper presents the new development for enhancement the performance of Power Management in Smart Home simulator. This development is based on the anticipatory and multi agent systems that used in this simulator.

  10. Structure Identification of Uncertain Complex Networks Based on Anticipatory Projective Synchronization.

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    Liu Heng

    Full Text Available This paper investigates a method to identify uncertain system parameters and unknown topological structure in general complex networks with or without time delay. A complex network, which has uncertain topology and unknown parameters, is designed as a drive network, and a known response complex network with an input controller is designed to identify the drive network. Under the proposed input controller, the drive network and the response network can achieve anticipatory projective synchronization when the system is steady. Lyapunov theorem and Barbǎlat's lemma guarantee the stability of synchronization manifold between two networks. When the synchronization is achieved, the system parameters and topology in response network can be changed to equal with the parameters and topology in drive network. A numerical example is given to show the effectiveness of the proposed method.

  11. Temperament, stereotypies and anticipatory behaviour as measures of welfare in mink

    DEFF Research Database (Denmark)

    Hansen, Steffen W.; Jeppesen, Leif Lau

    2006-01-01

    as a measure of poor welfare. On this basis, it was interesting to see if the sensitivity to a reward as expressed by the level of anticipatory behaviour of high and low stereotyping mink would clarify the discrepancy between the two classical measures of welfare. Twenty-four of the most stereotyping animals...... and 24 of the non-stereotyping animals were selected and exposed to Pavlovian conditioning with both positive and negative rewards. Their behaviour during anticipation of the reward changed, however, they also showed a great variation and dependence on feeding time as well as stereotypy status. So......A farm mink population of 290 1-year-old wild-coloured females was scanned for stereotyped behaviour in October 2003. At the same time the temperament of the individuals was established with a stick test. Some of the females performed no stereotypies in 54 scans and this fraction of the population...

  12. Size-weight illusion and anticipatory grip force scaling following unilateral cortical brain lesion.

    Science.gov (United States)

    Li, Yong; Randerath, Jennifer; Goldenberg, Georg; Hermsdörfer, Joachim

    2011-04-01

    The prediction of object weight from its size is an important prerequisite of skillful object manipulation. Grip and load forces anticipate object size during early phases of lifting an object. A mismatch between predicted and actual weight when two different sized objects have the same weight results in the size-weight illusion (SWI), the small object feeling heavier. This study explores whether lateralized brain lesions in patients with or without apraxia alter the size-weight illusion and impair anticipatory finger force scaling. Twenty patients with left brain damage (LBD, 10 with apraxia, 10 without apraxia), ten patients with right brain damage (RBD), and matched control subjects lifted two different-sized boxes in alternation. All subjects experienced a similar size-weight illusion. The anticipatory force scaling of all groups was in correspondence with the size cue: higher forces and force rates were applied to the big box and lower forces and force rates to the small box during the first lifts. Within few lifts, forces were scaled to actual object weight. Despite the lack of significant differences at group level, 5 out of 20 LBD patients showed abnormal predictive scaling of grip forces. They differed from the LBD patients with normal predictive scaling by a greater incidence of posterior occipito-parietal lesions but not by a greater incidence of apraxia. The findings do not support a more general role for the motor-dominant left hemisphere, or an influence of apraxia per se, in the scaling of finger force according to object properties. However, damage in the vicinity of the parietal-occipital junction may be critical for deriving predictions of weight from size.

  13. Impaired anticipatory control of force sharing patterns during whole-hand grasping in Parkinson's disease.

    Science.gov (United States)

    Muratori, Lisa M; McIsaac, Tara L; Gordon, Andrew M; Santello, Marco

    2008-02-01

    We examined the coordination of multi-digit grasping forces as they developed during object grasping and lifting. Ten subjects with Parkinson's disease (PD; OFF and ON medication) and ten healthy age-matched control subjects lifted a manipulandum that measured normal forces at each digit and the manipulandum's position. The center of mass (CM) was changed from trial to trial in either a predictable (blocked) or unpredictable (random) order. All subjects modulated individual fingertip forces to counterbalance forces exerted by the thumb and minimize object tilt after lift-off. However, subjects with PD OFF exhibited an impaired ability to use anticipatory mechanisms resulting in less differentiated scaling of individual finger forces to the object CM location. Remarkably, these between-group differences in force modulation dissipated as subjects reached peak grip forces during object lift, although these occurred significantly later in subjects with PD OFF than controls and PD ON. Analysis of the tilt of the object during lift revealed all subjects had similar deviations of the object from the vertical, the direction of which depended on CM location. Thus these findings in subjects with PD indicate that: (a) PD-induced impairments in anticipatory force mechanisms appear to be greatly increased in multi-digit grasping as opposed to previous reports from two-digit grasping; (b) inaccurate scaling of fingertip force amplitude and sharing patterns before object lift is recovered during object lift; (c) the implementation of appropriate force amplitude and sharing among the digits during the lift occurs significantly later than for controls; (d) medication improves the temporal recovery of multi-digit force coordination. These results are discussed within the framework of PD-related deficits in sensorimotor integration and control of multi-degrees of freedom movement.

  14. Circadian regulation of food-anticipatory activity in molecular clock-deficient mice.

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    Nana N Takasu

    Full Text Available In the mammalian brain, the suprachiasmatic nucleus (SCN of the anterior hypothalamus is considered to be the principal circadian pacemaker, keeping the rhythm of most physiological and behavioral processes on the basis of light/dark cycles. Because restriction of food availability to a certain time of day elicits anticipatory behavior even after ablation of the SCN, such behavior has been assumed to be under the control of another circadian oscillator. According to recent studies, however, mutant mice lacking circadian clock function exhibit normal food-anticipatory activity (FAA, a daily increase in locomotor activity preceding periodic feeding, suggesting that FAA is independent of the known circadian oscillator. To investigate the molecular basis of FAA, we examined oscillatory properties in mice lacking molecular clock components. Mice with SCN lesions or with mutant circadian periods were exposed to restricted feeding schedules at periods within and outside circadian range. Periodic feeding led to the entrainment of FAA rhythms only within a limited circadian range. Cry1(-/- mice, which are known to be a "short-period mutant," entrained to a shorter period of feeding cycles than did Cry2(-/- mice. This result indicated that the intrinsic periods of FAA rhythms are also affected by Cry deficiency. Bmal1(-/- mice, deficient in another essential element of the molecular clock machinery, exhibited a pre-feeding increase of activity far from circadian range, indicating a deficit in circadian oscillation. We propose that mice possess a food-entrainable pacemaker outside the SCN in which canonical clock genes such as Cry1, Cry2 and Bmal1 play essential roles in regulating FAA in a circadian oscillatory manner.

  15. Right prefrontal TMS disrupts interregional anticipatory EEG alpha activity during shifting of visuospatial attention

    Directory of Open Access Journals (Sweden)

    Paul eSauseng

    2011-10-01

    Full Text Available Visual attention can be shifted in space without moving the eyes. Amplitude decrease of rhythmical brain activity around 10 Hz (so called alpha activity at contralateral posterior sites has been reported during covert shifts of visuospatial attention to one visual hemifield. Alpha amplitude increase, on the other hand, can be found at ipsilateral visual cortex. There is some evidence suggesting an involvement of prefrontal brain areas during the control of attention-related anticipatory alpha amplitude asymmetry. However, the exact neural mechanism by which prefrontal cortex influences visual processing has not been completely clear yet. This open question has been studied in detail using a multimodal approach combining transcranial magnetic stimulation (TMS and multichannel electroencephalography (EEG in healthy humans. Slow (1 Hz repetitive TMS inducing an inhibitory effect at the stimulation site was delivered either to right frontal eye field or a control site (vertex. Subsequently, participants had to perform a spatial cueing task in which covert shifts of attention were required to either the left or the right visual hemi-field. After stimulation at the vertex (control condition a pattern of anticipatory, attention-related ipsilateral alpha increase / contralateral alpha decrease over posterior recording sites could be obtained. Additionally, there was pronounced coupling between (in particular right FEF and posterior brain sites. When, however, the right prefrontal cortex had been virtually lesioned preceding the task, these EEG correlates of visuospatial attention were attenuated. Notably, the effect of TMS at the right FEF on interregional fronto-parietal alpha coupling predicted the effect on response times. This suggests that visual attention processes associated with posterior EEG alpha activity are at least partly top-down controlled by the prefrontal cortex.

  16. Circadian regulation of food-anticipatory activity in molecular clock-deficient mice.

    Science.gov (United States)

    Takasu, Nana N; Kurosawa, Gen; Tokuda, Isao T; Mochizuki, Atsushi; Todo, Takeshi; Nakamura, Wataru

    2012-01-01

    In the mammalian brain, the suprachiasmatic nucleus (SCN) of the anterior hypothalamus is considered to be the principal circadian pacemaker, keeping the rhythm of most physiological and behavioral processes on the basis of light/dark cycles. Because restriction of food availability to a certain time of day elicits anticipatory behavior even after ablation of the SCN, such behavior has been assumed to be under the control of another circadian oscillator. According to recent studies, however, mutant mice lacking circadian clock function exhibit normal food-anticipatory activity (FAA), a daily increase in locomotor activity preceding periodic feeding, suggesting that FAA is independent of the known circadian oscillator. To investigate the molecular basis of FAA, we examined oscillatory properties in mice lacking molecular clock components. Mice with SCN lesions or with mutant circadian periods were exposed to restricted feeding schedules at periods within and outside circadian range. Periodic feeding led to the entrainment of FAA rhythms only within a limited circadian range. Cry1(-/-) mice, which are known to be a "short-period mutant," entrained to a shorter period of feeding cycles than did Cry2(-/-) mice. This result indicated that the intrinsic periods of FAA rhythms are also affected by Cry deficiency. Bmal1(-/-) mice, deficient in another essential element of the molecular clock machinery, exhibited a pre-feeding increase of activity far from circadian range, indicating a deficit in circadian oscillation. We propose that mice possess a food-entrainable pacemaker outside the SCN in which canonical clock genes such as Cry1, Cry2 and Bmal1 play essential roles in regulating FAA in a circadian oscillatory manner.

  17. Effect of Experimentally-Induced Trunk Muscular Tensions on the Sit-to-Stand Task Performance and Associated Postural Adjustments.

    Science.gov (United States)

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

    It has been shown that increased muscular activity along the trunk is likely to impair body balance, but there is little knowledge about its consequences on more dynamic tasks. The purpose of this study was to determine the effect of unilateral and bilateral increases of muscular tension along the trunk on the sit-to-stand task (STS) performance and associated anticipatory postural adjustments (APAs). Twelve healthy females (23 ± 3 years, 163 ± 0.06 cm, 56 ± 9 kg), free of any neurological or musculoskeletal disorders, performed six trials of the STS at maximum speed, in seven experimental conditions varying the muscular tension along each side of the trunk, using a specific bimanual compressive load paradigm. A six-channel force plate was used to calculate the coordinates of the center of pressure (CP) along the anterior-posterior and medial-lateral axes, and the kinematics of the head, spine and pelvis, were estimated using three pairs of uni-axial accelerometers. The postural and focal components of the task were assessed using three biomechanical parameters calculated from CP signals: the duration and magnitude of APAs, and the duration of focal movement (dFM). Results showed that beyond a given level, higher muscular tension along the trunk results in longer APAs, but with a stable duration of the focal movement. In addition, no significant variation of APAs and FM parameters was found between bilateral and unilateral increases of muscular tension. It was suggested that restricted mobility due to higher muscular tension along the trunk requires an adaptation of the programming of APAs to keep the same level of performance in the STS task. These findings may have implications in treatment strategies aimed at preserving functional autonomy in pathologies including a rise of muscular tension.

  18. Effect of Experimentally-Induced Trunk Muscular Tensions on the Sit-to-Stand Task Performance and Associated Postural Adjustments

    Science.gov (United States)

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

    It has been shown that increased muscular activity along the trunk is likely to impair body balance, but there is little knowledge about its consequences on more dynamic tasks. The purpose of this study was to determine the effect of unilateral and bilateral increases of muscular tension along the trunk on the sit-to-stand task (STS) performance and associated anticipatory postural adjustments (APAs). Twelve healthy females (23 ± 3 years, 163 ± 0.06 cm, 56 ± 9 kg), free of any neurological or musculoskeletal disorders, performed six trials of the STS at maximum speed, in seven experimental conditions varying the muscular tension along each side of the trunk, using a specific bimanual compressive load paradigm. A six-channel force plate was used to calculate the coordinates of the center of pressure (CP) along the anterior-posterior and medial-lateral axes, and the kinematics of the head, spine and pelvis, were estimated using three pairs of uni-axial accelerometers. The postural and focal components of the task were assessed using three biomechanical parameters calculated from CP signals: the duration and magnitude of APAs, and the duration of focal movement (dFM). Results showed that beyond a given level, higher muscular tension along the trunk results in longer APAs, but with a stable duration of the focal movement. In addition, no significant variation of APAs and FM parameters was found between bilateral and unilateral increases of muscular tension. It was suggested that restricted mobility due to higher muscular tension along the trunk requires an adaptation of the programming of APAs to keep the same level of performance in the STS task. These findings may have implications in treatment strategies aimed at preserving functional autonomy in pathologies including a rise of muscular tension.

  19. 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.

  20. 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.

  1. 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.

  2. Strategic political postures and political market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Henneberg, Stephan C.

    2010-01-01

    , these have yet to be integrated to provide a more nuanced framework which both researchers and political marketing practitioners can utilise in the development of strategies and offerings with which to achieve their organizational goals. The aim of this conceptual paper is to address this deficit......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...

  3. Reductions in self-reported stress and anticipatory heart rate with the use of a semi-automated parallel parking system.

    Science.gov (United States)

    Reimer, Bryan; Mehler, Bruce; Coughlin, Joseph F

    2016-01-01

    Drivers' reactions to a semi-autonomous technology for assisted parallel parking system were evaluated in a field experiment. A sample of 42 drivers balanced by gender and across three age groups (20-29, 40-49, 60-69) were given a comprehensive briefing, saw the technology demonstrated, practiced parallel parking 3 times each with and without the assistive technology, and then were assessed on an additional 3 parking events each with and without the technology. Anticipatory stress, as measured by heart rate, was significantly lower when drivers approached a parking space knowing that they would be using the assistive technology as opposed to manually parking. Self-reported stress levels following assisted parks were also lower. Thus, both subjective and objective data support the position that the assistive technology reduced stress levels in drivers who were given detailed training. It was observed that drivers decreased their use of turn signals when using the semi-autonomous technology, raising a caution concerning unintended lapses in safe driving behaviors that may occur when assistive technologies are used.

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. 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.

  10. Where do you end and I begin? Evidence for anticipatory, motivated self-other integration between relationship partners.

    Science.gov (United States)

    Slotter, Erica B; Gardner, Wendi L

    2009-06-01

    Perceiving similarity between oneself and one's romantic partner benefits both the individual and the relationship and can arise from multiple pathways that draw either the partner closer to the self or the self closer to the partner. The current research focuses on the latter. The authors investigate novel circumstances under which the self-concepts of individuals in romantic relationships may intertwine. Although self-other integration typically grows from the depth of shared experiences between relationship partners, the current research proposes a secondary pathway through which self-other integration may occur: Specifically, motivation to draw close to a romantic partner may be sufficient to evoke self-other integration even in the absence of shared experience. In 6 studies, the authors explored this anticipatory self-other integration pathway, using both current and potential romantic partners. The results supported the hypotheses by demonstrating that self-other integration can occur in an anticipatory fashion with the appropriate motivation.

  11. 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. ...

  12. 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...

  13. 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...

  14. 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...

  15. Objective Markers of Postural Instability in Parkinson’s Disease

    Science.gov (United States)

    2005-11-01

    Stage 3, sway variability differentiated PD patients and controls. There was only one significant correlation, which was between the UPDRS posture score...sway pattern complexity, and sway nonstationarity). Sway variability (AP) and sway nonstationarity significantly predicted the UPDRS posture scores...the objective measures of postural instability to clinical ratings of PD severity, the Unified Parkinson’s Disease Rating Scale ( UPDRS ; Fahn et al

  16. 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...

  17. 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....

  18. 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

  19. Effect of Semi-Rigid and Soft Ankle Braces on Static and Dynamic Postural Stability in Young Male Adults

    Science.gov (United States)

    Maeda, Noriaki; Urabe, Yukio; Tsutsumi, Shogo; Numano, Shuhei; Morita, Miho; Takeuchi, Takuya; Iwata, Shou; Kobayashi, Toshiki

    2016-01-01

    Ankle braces have been suggested to protect ankle joints from a sprain by restricting inversion and improving proprioception. However, the difference in effects between a semi-rigid brace and a soft brace regarding dynamic postural control after landing is not known. The aim of the present study was to compare the effect of soft (SB) and semi-rigid (SRB) ankle braces on static and dynamic postural stability in healthy young men. Altogether, 21 male adults (mean age 24.0 ± 1.5 years) were assessed for one leg while wearing non-brace (NB), SB or SRB. Balance in single-limb stance on a single-force platform with open eyes and closed eyes were assessed for the non-dominant leg under SB, SRB, and NB conditions. Locus length/second (mm/s) and the enveloped area (mm·s-2) surrounded by the circumference of the wave pattern during postural sway were calculated. For assessing dynamic postural stability, the participant jumped and landed on one leg on a force platform, and the Dynamic Postural Stability Index (DPSI) and the maximum vertical ground reaction force (vGRFmax) were measured. The data were compared among the three conditions with repeated-measures analysis of variance. The correlations between locus length/second, enveloped area, DPSI values (DPSI, Anterior-Posterior Stability Index, Medial-Lateral Stability Index, and Vertical Stability Index), and vGRFmax were then calculated. The results indicated that locus length/second and enveloped area with open eyes and closed eyes were not significantly different for each condition. However, a significant lower in the DPSI and Vertical Stability Index were observed with the SRB in comparison to the SB and NB. A significant improvement in vGRFmax was also observed with the SRB in comparison to NB. SRB demonstrated a positive effect on dynamic postural stability after landing on a single leg and may improve balance by increasing dynamic postural stability. Key points This study examined the effect of ankle braces on

  20. 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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Good stress, bad stress and oxidative stress: insights from anticipatory cortisol reactivity.

    Science.gov (United States)

    Aschbacher, Kirstin; O'Donovan, Aoife; Wolkowitz, Owen M; Dhabhar, Firdaus S; Su, Yali; Epel, Elissa

    2013-09-01

    Chronic psychological stress appears to accelerate biological aging, and oxidative damage is an important potential mediator of this process. However, the mechanisms by which psychological stress promotes oxidative damage are poorly understood. This study investigates the theory that cortisol increases in response to an acutely stressful event have the potential to either enhance or undermine psychobiological resilience to oxidative damage, depending on the body's prior exposure to chronic psychological stress. In order to achieve a range of chronic stress exposure, forty-eight post-menopausal women were recruited in a case-control design that matched women caring for spouses with dementia (a chronic stress model) with similarly aged control women whose spouses were healthy. Participants completed a questionnaire assessing perceived stress over the previous month and provided fasting blood. Three markers of oxidative damage were assessed: 8-iso-prostaglandin F(2α) (IsoP), lipid peroxidation, 8-hydroxyguanosine (8-oxoG) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), reflecting oxidative damage to RNA/DNA respectively. Within approximately one week, participants completed a standardized acute laboratory stress task while salivary cortisol responses were measured. The increase from 0 to 30 min was defined as "peak" cortisol reactivity, while the increase from 0 to 15 min was defined as "anticipatory" cortisol reactivity, representing a cortisol response that began while preparing for the stress task. Women under chronic stress had higher 8-oxoG, oxidative damage to RNA (pcortisol reactivity would mediate the relationship between perceived stress and elevated oxidative stress damage, but only among women under chronic stress. Consistent with this model, bootstrapped path analysis found significant indirect paths from perceived stress to 8-oxoG and IsoP (but not 8-OHdG) via anticipatory cortisol reactivity, showing the expected relations among chronically stressed

  13. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. 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

  17. Grammatical number processing and anticipatory eye movements are not tightly coordinated in English spoken language comprehension

    Directory of Open Access Journals (Sweden)

    Brian eRiordan

    2015-05-01

    Full Text Available Recent studies of eye movements in world-situated language comprehension have demonstrated that rapid processing of morphosyntactic information – e.g., grammatical gender and number marking – can produce anticipatory eye movements to referents in the visual scene. We investigated how type of morphosyntactic information and the goals of language users in comprehension affected eye movements, focusing on the processing of grammatical number morphology in English-speaking adults. Participants’ eye movements were recorded as they listened to simple English declarative (There are the lions. and interrogative (Where are the lions? sentences. In Experiment 1, no differences were observed in speed to fixate target referents when grammatical number information was informative relative to when it was not. The same result was obtained in a speeded task (Experiment 2 and in a task using mixed sentence types (Experiment 3. We conclude that grammatical number processing in English and eye movements to potential referents are not tightly coordinated. These results suggest limits on the role of predictive eye movements in concurrent linguistic and scene processing. We discuss how these results can inform and constrain predictive approaches to language processing.

  18. Digit Position and Forces Covary during Anticipatory Control of Whole-Hand Manipulation.

    Science.gov (United States)

    Marneweck, Michelle; Lee-Miller, Trevor; Santello, Marco; Gordon, Andrew M

    2016-01-01

    Theoretical perspectives on anticipatory planning of object manipulation have traditionally been informed by studies that have investigated kinematics (hand shaping and digit position) and kinetics (forces) in isolation. This poses limitations on our understanding of the integration of such domains, which have recently been shown to be strongly interdependent. Specifically, recent studies revealed strong covariation of digit position and load force during the loading phase of two-digit grasping. Here, we determined whether such digit force-position covariation is a general feature of grasping. We investigated the coordination of digit position and forces during five-digit whole-hand manipulation of an object with a variable mass distribution. Subjects were instructed to prevent object roll during the lift. As found in precision grasping, there was strong trial-to-trial covariation of digit position and force. This suggests that the natural variation of digit position that is compensated for by trial-to-trial variation in digit forces is a fundamental feature of grasp control, and not only specific to precision grasp. However, a main difference with precision grasping was that modulation of digit position to the object's mass distribution was driven predominantly by the thumb, with little to no modulation of finger position. Modulation of thumb position rather than fingers is likely due to its greater range of motion and therefore adaptability to object properties. Our results underscore the flexibility of the central nervous system in implementing a range of solutions along the digit force-to-position continuum for dexterous manipulation.

  19. Food-anticipatory activity and liver per1-luc activity in diabetic transgenic rats

    Science.gov (United States)

    Davidson, Alec J.; Stokkan, Karl-Arne; Yamazaki, Shin; Menaker, Michael

    2002-01-01

    The mammalian Per1 gene is an important component of the core cellular clock mechanism responsible for circadian rhythms. The rodent liver and other tissues rhythmically express Per1 in vitro but typically damp out within a few cycles. In the liver, the peak of this rhythm occurs in the late subjective night in an ad lib-fed rat, but will show a large phase advance in response to restricted availability of food during the day. The relationship between this shift in the liver clock and food-anticipatory activity (FAA), the circadian behavior entrained by daily feeding, is currently unknown. Insulin is released during feeding in mammals and could serve as an entraining signal to the liver. To test the role of insulin in the shift in liver Per1 expression and the generation of FAA, per-luciferase transgenic rats were made diabetic with a single injection of streptozotocine. Following 1 week of restricted feeding and locomotor activity monitoring, liver was collected for per-luc recording. In two separate experiments, FAA emerged and liver Per1 phase-shifted in response to daytime 8-h food restriction. The results rule out insulin as a necessary component of this system.

  20. Anticipatory control and spatial cognition in locomotion and navigation through typical development and in cerebral palsy.

    Science.gov (United States)

    Belmonti, Vittorio; Cioni, Giovanni; Berthoz, Alain

    2016-03-01

    Behavioural evidence, summarized in this narrative review, supports a developmental model of locomotor control based on increasing neural integration of spatial reference frames. Two consistent adult locomotor behaviours are head stabilization and head anticipation: the head is stabilized to gravity and leads walking direction. This cephalocaudal orienting organization aligns gaze and vestibula with a reference frame centred on the upcoming walking direction, allowing anticipatory control on body kinematics, but is not fully developed until adolescence. Walking trajectories and those of hand movements share many aspects, including power laws coupling velocity to curvature, and minimized spatial variability. In fact, the adult brain can code trajectory geometry in an allocentric reference frame, irrespective of the end effector, regulating body kinematics thereafter. Locomotor trajectory formation, like head anticipation, matures in early adolescence, indicating common neurocomputational substrates. These late-developing control mechanisms can be distinguished from biomechanical problems in children with cerebral palsy (CP). Children's performance on a novel navigation test, the Magic Carpet, indicates that typical navigation development consists of the increasing integration of egocentric and allocentric reference frames. In CP, right-brain impairment seems to reduce navigation performance due to a maladaptive left-brain sequential egocentric strategy. Spatial integration should be considered more in rehabilitation.

  1. Anticipatory modulation of neck muscle reflex responses induced by mechanical perturbations of the human forehead.

    Science.gov (United States)

    Kuramochi, Rieko; Kimura, Toshitaka; Nakazawa, Kimitaka; Akai, Masami; Torii, Suguru; Suzuki, Shuji

    2004-08-12

    The aim of this study was to test whether anticipation of upcoming head blow stimuli, which elicit reflex responses in the neck muscle, makes the reflex responses greater or not. In nine healthy subjects the reflex responses were elicited in the sternocleidomastoid (SCM) muscle in the eyes-open (EO) and eyes-closed (EC) conditions, which corresponded to the predictable and unpredictable conditions, respectively. The subjects were instructed not to resist the perturbations after the impact. The results demonstrated that the reflex response of the SCM muscle was significantly smaller in the predictable EO condition than in the unpredictable EC condition (P component, which most probably mediated the stretch reflex pathway. In contrast, no significant difference was observed in the early component, which was presumed to be the vestibular-collic reflex. The reduced stretch reflex response was suggested to be functionally relevant to the task requirement, i.e., to let the neck extension movement occur, and not to resist after the impact of the head blow. It was concluded that the anticipation has an effect on reducing the stretch reflex responses in the neck muscle, but does not have any effect on the presumed vestibular-collic reflex under the present experimental paradigm. It is suggested that the gain of the stretch reflex pathway is modulated by anticipatory information of upcoming mechanical event.

  2. Anticipatory eye movements evoked after active following versus passive observation of a predictable motion stimulus.

    Science.gov (United States)

    Burke, M R; Barnes, G R

    2008-12-15

    We used passive and active following of a predictable smooth pursuit stimulus in order to establish if predictive eye movement responses are equivalent under both passive and active conditions. The smooth pursuit stimulus was presented in pairs that were either 'predictable' in which both presentations were matched in timing and velocity, or 'randomized' in which each presentation in the pair was varied in both timing and velocity. A visual cue signaled the type of response required from the subject; a green cue indicated the subject should follow both the target presentations (Go-Go), a pink cue indicated that the subject should passively observe the 1st target and follow the 2nd target (NoGo-Go), and finally a green cue with a black cross revealed a randomized (Rnd) trial in which the subject should follow both presentations. The results revealed better prediction in the Go-Go trials than in the NoGo-Go trials, as indicated by higher anticipatory velocity and earlier eye movement onset (latency). We conclude that velocity and timing information stored from passive observation of a moving target is diminished when compared to active following of the target. This study has significant consequences for understanding how visuomotor memory is generated, stored and subsequently released from short-term memory.

  3. 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…

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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…

  9. 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.

  10. 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

  11. 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.

  12. 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...

  13. 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.

  14. 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.…

  15. 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

  16. 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.…

  17. 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

  18. 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

  19. 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.

  20. 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…

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Integrating multiple sensory systems to modulate neural networks controlling posture.

    Science.gov (United States)

    Lavrov, I; Gerasimenko, Y; Burdick, J; Zhong, H; Roy, R R; Edgerton, V R

    2015-12-01

    In this study we investigated the ability of sensory input to produce tonic responses in hindlimb muscles to facilitate standing in adult spinal rats and tested two hypotheses: 1) whether the spinal neural networks below a complete spinal cord transection can produce tonic reactions by activating different sensory inputs and 2) whether facilitation of tonic and rhythmic responses via activation of afferents and with spinal cord stimulation could engage similar neuronal mechanisms. We used a dynamically controlled platform to generate vibration during weight bearing, epidural stimulation (at spinal cord level S1), and/or tail pinching to determine the postural control responses that can be generated by the lumbosacral spinal cord. We observed that a combination of platform displacement, epidural stimulation, and tail pinching produces a cumulative effect that progressively enhances tonic responses in the hindlimbs. Tonic responses produced by epidural stimulation alone during standing were represented mainly by monosynaptic responses, whereas the combination of epidural stimulation and tail pinching during standing or epidural stimulation during stepping on a treadmill facilitated bilaterally both monosynaptic and polysynaptic responses. The results demonstrate that tonic muscle activity after complete spinal cord injury can be facilitated by activation of specific combinations of afferent inputs associated with load-bearing proprioception and cutaneous input in the presence of epidural stimulation and indicate that whether activation of tonic or rhythmic responses is generated depends on the specific combinations of sources and types of afferents activated in the hindlimb muscles.

  8. 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.

  9. 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.

  10. Effects of 16 - week Tai Chi intervention on postural stability and associated physiological factors in older people

    Institute of Scientific and Technical Information of China (English)

    洪友廉

    2007-01-01

    Objectives :To examine the effects of 16 - week Tai Chi (TC) training on postural stability and associated physiological factors in older subjects,forty elderly individuals (aged ≥ 60 years) living in the community were randomly placed into either the TC intervention group ( n = 22) or the control group (n = 18). The former underwent a supervised TC exercise program for 16 weeks, while the latter received general education for a comparable time period. Measurements:Postural stability was assessed by timed stance tests in single - leg stance with the eyes open (SLO) or closed (SLC), and tandem stance with the eyes closed (TSC). Proprioceptive function was evaluated by measuring ankle and knee kinesthesia. The maximum concentric strength of the knee flexors and extensors,ankle plantarflexors and dorsiflexors was measured by isokinetic dynamometer. Moreover, the reaction time of different muscles in the lower extremity was also examined by measuring the onset latency of the muscles to perturbations on the ankle joint using an electromyography system. Results :After the 16-week TC intervention, significant TC training effects were gained on knee kinesthesia, knee flexor strength, latency of semitendinous muscle, and postural stability in SLO. For the other measures,no significant training effects were found. Conclusions: The 16 - week TC intervention was found to be beneficial for the improvement of postural stability and associated physiological factors. However, there are discrepancies in TC training effects on different factors in the sensorimotor system.

  11. 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.

  12. 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

  13. 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

  14. Sensorimotor integration in human postural control

    Science.gov (United States)

    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

  15. Cybersemiotics: A suggestion for a transdisciplinary framework for description of observing, anticipatory and meaning producing systems

    Science.gov (United States)

    Brier, Soren

    1998-07-01

    The ability of systems to be anticipatory seems to be intricate connected with the ability to observe and to cognate by reducing complexity through signification. The semantic capacity of living systems, the cognitive ability to assign meaning to differences perturbating the system's self-organization, seems to be the prerequisite for the phenomenon of communication, language and consciousness. In cybernetics Bateson developed the idea that information is a difference that makes a difference and second order cybernetics developed the concept of organisms as self-organized and self-produced systems (autopoietic) as the prerequisite of life and cognition. The cognitive ability seems to be qualitative different from what so far is computable on any known machine although parts of different aspects of the process can be partly simulated in AI, neutral network and AL. In semiotics the fundamental process of cognition and communication is called semiosis or signification and C. S. Peirce created a special triadic, objective idealistic, pragmatic and evolutionary philosophy to be able to give a fruitful description of the process and its relation to logic and the concept of natural law. Both second order cybernetics and semiotics sees information and meaning as something produced by individual organisms through structural couplings to the environments or other individuals through historical drift and further developed in social communication. Luhmann points out that social communication also only functions through structural couplings which he calls generalized media such as science, art, power, love and money. Peirce talks of the semiotic net as a triadic view of meanings developing through history and in animals through evolution. In accordance with this Wittgenstein points out that signification is created in language games developed in specific life forms. Life forms are the things we do in society such as seducing, commanding and explaining. As animals do not have

  16. Anticipating on amplifying water stress: Optimal crop production supported by anticipatory water management

    Science.gov (United States)

    Bartholomeus, Ruud; van den Eertwegh, Gé; Simons, Gijs

    2015-04-01

    Agricultural crop yields depend largely on the soil moisture conditions in the root zone. Drought but especially an excess of water in the root zone and herewith limited availability of soil oxygen reduces crop yield. With ongoing climate change, more prolonged dry periods alternate with more intensive rainfall events, which changes soil moisture dynamics. With unaltered water management practices, reduced crop yield due to both drought stress and waterlogging will increase. Therefore, both farmers and water management authorities need to be provided with opportunities to reduce risks of decreasing crop yields. In The Netherlands, agricultural production of crops represents a market exceeding 2 billion euros annually. Given the increased variability in meteorological conditions and the resulting larger variations in soil moisture contents, it is of large economic importance to provide farmers and water management authorities with tools to mitigate risks of reduced crop yield by anticipatory water management, both at field and at regional scale. We provide the development and the field application of a decision support system (DSS), which allows to optimize crop yield by timely anticipation on drought and waterlogging situations. By using this DSS, we will minimize plant water stress through automated drainage and irrigation management. In order to optimize soil moisture conditions for crop growth, the interacting processes in the soil-plant-atmosphere system need to be considered explicitly. Our study comprises both the set-up and application of the DSS on a pilot plot in The Netherlands, in order to evaluate its implementation into daily agricultural practice. The DSS focusses on anticipatory water management at the field scale, i.e. the unit scale of interest to a farmer. We combine parallel field measurements ('observe'), process-based model simulations ('predict'), and the novel Climate Adaptive Drainage (CAD) system ('adjust') to optimize soil moisture

  17. 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.

  18. 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.

  19. 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.

  20. Global body posture evaluation in patients with temporomandibular joint disorder

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    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.

  1. Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults.

    Science.gov (United States)

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

    2016-01-01

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

  2. PENINGKATAN STABILITAS POSTURAL PADA LANSIA MELALUI BALANCE EXERCISE

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    Kusnanto .

    2010-12-01

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

  3. Ready, set, go! Low anticipatory response during a dyadic task in infants at high familial risk for autism

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    Rebecca J Landa

    2016-05-01

    Full Text Available Children with Autism Spectrum Disorder (ASD demonstrate a host of motor impairments that may share a common developmental basis with ASD core symptoms. School-age children with ASD exhibit particular difficulty with hand-eye coordination and appear to be less sensitive to visual feedback during motor learning. Sensorimotor deficits are observable as early as 6 months of age in children who later develop ASD; yet the interplay of early motor, visual and social skill development in ASD is not well understood. Integration of visual input with motor output is vital for the formation of internal models of action. Such integration is necessary not only to master a wide range of motor skills, but also to imitate and interpret the actions of others. Thus, closer examination of the early development of visual-motor deficits is of critical importance to ASD. In the present study of infants at high risk (HR and low risk (LR for ASD, we examined visual-motor coupling, or action anticipation, during a dynamic, interactive ball-rolling activity. We hypothesized that, compared to LR infants, HR infants would display decreased anticipatory response (perception-guided predictive action to the approaching ball. We also examined visual attention before and during ball rolling to determine whether attention engagement contributed to differences in anticipation. Results showed that LR and HR infants demonstrated context appropriate looking behavior, both before and during the ball’s trajectory toward them. However, HR infants were less likely to exhibit context appropriate anticipatory motor response to the approaching ball (moving their arm/hand to intercept the ball than LR infants. This finding did not appear to be driven by differences in motor skill between risk groups at 6 months of age and was extended to show an atypical predictive relationship between anticipatory behavior at 6 months and preference for looking at faces compared to objects at age 14

  4. Meditation experience predicts less negative appraisal of pain: electrophysiological evidence for the involvement of anticipatory neural responses.

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    Brown, Christopher A; Jones, Anthony K P

    2010-09-01

    The aim of mindfulness meditation is to develop present-focused, non-judgmental, attention. Therefore, experience in meditation should be associated with less anticipation and negative appraisal of pain. In this study we compared a group of individuals with meditation experience to a control group to test whether any differences in the affective appraisal of pain could be explained by lower anticipatory neural processing. Anticipatory and pain-evoked ERPs and reported pain unpleasantness were recorded in response to laser stimuli of matched subjective intensity between the two groups. ERP data were analysed after source estimation with LORETA. No group effects were found on the laser energies used to induce pain. More experienced meditators perceived the pain as less unpleasant relative to controls, with meditation experience correlating inversely with unpleasantness ratings. ERP source data for anticipation showed that in meditators, lower activity in midcingulate cortex relative to controls was related to the lower unpleasantness ratings, and was predicted by lifetime meditation experience. Meditators also reversed the normal positive correlation between medial prefrontal cortical activity and pain unpleasantness during anticipation. Meditation was also associated with lower activity in S2 and insula during the pain-evoked response, although the experiment could not disambiguate this activity from the preceding anticipation response. Our data is consistent with the hypothesis that meditation reduces the anticipation and negative appraisal of pain, but effects on pain-evoked activity are less clear and may originate from preceding anticipatory activity. Further work is required to directly test the causal relationship between meditation, pain anticipation, and pain experience.

  5. Anticipatory maternal effects in two different clones of Daphnia magna in response to food shortage

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    Valeria ROSSI

    2011-08-01

    Full Text Available The effects of food shortage on growth, fecundity, male production and offspring size and starvation tolerance in two different clones of Daphnia magna (Clone L and Clone P were evaluated by disentangling the effects of resource depletion and crowding per se. Three experimental conditions were tested: high food - low daphnid density (the optimum, low food - low daphnid density and high food - high daphnid density. In the two first conditions, daphnids experienced the same population density but they had different food availability. In the two latter conditions, daphnids had the same per capita, low, food availability but they lived at different algae and daphnid densities. Moreover, the response of crowded females to recovery at high food availability and low population density was evaluated. Low food availability reduced growth and fecundity of both clones and increased male production only in the Clone L. Crowding per se did not affect growth but reduced fecundity. In both clones, low food availability due to low algae density enhanced investment in offspring size and resistance to starvation. In response to food shortage either due to low algae density and to crowding, Clone P increased the investment in offspring size and starvation tolerance but reduced fecundity to a lesser extent than Clone L and did not produce males. Clone L, in response to food shortage due to crowding at high algae density, increased development time, produced more males, as at low algae density, but halved fecundity producing offspring that were not starvationtolerant. These results might reflect differences in anticipatory maternal effects between clones and suggest that neonate quality varies according to either, the environment the mother experienced and the competitive environment the neonates will cope due to their mother life strategy.

  6. A circadian clock in the olfactory bulb anticipates feeding during food anticipatory activity.

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    Nahum Nolasco

    Full Text Available Rabbit pups ingest food, in this case milk, once a day with circadian periodicity and are a natural model of food anticipatory activity. During nursing, several sensory systems receive information about properties of the food, one of them being the olfactory system, which has received little attention in relation to synchronization by food. In addition, the olfactory bulb has a circadian pacemaker that exhibits rhythms independently of the suprachiasmatic nucleus, but the biological functions of these rhythms are largely unknown. In the present contribution, we hypothesized that circadian suckling of milk synchronizes rhythms in the olfactory bulb. To this aim we explored by immunohistochemistry, rhythms of FOS and PER1 proteins, as indicators of activation and reporter of oscillations, respectively, through a complete 24-h cycle in periglomerular, mitral and granular cell layers of both the main and the accessory olfactory bulb. Subjects were 7-day-old rabbit pups scheduled to nurse during the night (02:00 h or day (10:00 h, and also fasted subjects, to explore the possible persistence of oscillations. In the three layers of the main olfactory bulb, FOS was high at time of nursing, then further increased 1.5 h afterward, and then decreased to increase again in advance of the next nursing bout. This pattern persisted, without the postprandial increase, in fasted subjects with a shift in subjects nursed at 02:00. PER1 was increased 2-8 h after nursing and this increase persisted in most cell layers, with a shift, in fasted subjects. In the accessory olfactory bulb we only observed a consistent pattern of FOS expression in the mitral cell layer of nursed subjects, similar to that of the main olfactory bulb. We conclude that the main olfactory bulb is synchronized during milk ingestion, but during fasting its oscillations perhaps are modulated by the suprachiasmatic nucleus, as proposed for rodents.

  7. Classification of Anticipatory Signals for Grasp and Release from Surface Electromyography.

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    Siu, Ho Chit; Shah, Julie A; Stirling, Leia A

    2016-10-25

    Surface electromyography (sEMG) is a technique for recording natural muscle activation signals, which can serve as control inputs for exoskeletons and prosthetic devices. Previous experiments have incorporated these signals using both classical and pattern-recognition control methods in order to actuate such devices. We used the results of an experiment incorporating grasp and release actions with object contact to develop an intent-recognition system based on Gaussian mixture models (GMM) and continuous-emission hidden Markov models (HMM) of sEMG data. We tested this system with data collected from 16 individuals using a forearm band with distributed sEMG sensors. The data contain trials with shifted band alignments to assess robustness to sensor placement. This study evaluated and found that pattern-recognition-based methods could classify transient anticipatory sEMG signals in the presence of shifted sensor placement and object contact. With the best-performing classifier, the effect of label lengths in the training data was also examined. A mean classification accuracy of 75.96% was achieved through a unigram HMM method with five mixture components. Classification accuracy on different sub-movements was found to be limited by the length of the shortest sub-movement, which means that shorter sub-movements within dynamic sequences require larger training sets to be classified correctly. This classification of user intent is a potential control mechanism for a dynamic grasping task involving user contact with external objects and noise. Further work is required to test its performance as part of an exoskeleton controller, which involves contact with actuated external surfaces.

  8. Digit Position and Forces Covary During Anticipatory Control of Whole-Hand Manipulation

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    Michelle Marneweck

    2016-09-01

    Full Text Available Theoretical perspectives on anticipatory planning of object manipulation have traditionally been informed by studies that have investigated kinematics (hand shaping and digit position and kinetics (forces in isolation. This poses limitations on our understanding of the integration of such domains, which have recently been shown to be strongly interdependent. Specifically, recent studies revealed strong covariation of digit position and load force during the loading phase of two-digit grasping. Here we determined whether such digit force-position covariation is a general feature of grasping. We investigated the coordination of digit position and forces during five-digit whole-hand manipulation of an object with a variable mass distribution. Subjects were instructed to prevent object roll during the lift. As found in precision grasping, there was strong trial-to-trial covariation of digit position and force. This suggests that the natural variation of digit position that is compensated for by trial-to-trial variation in digit forces is a fundamental feature of grasp control, and not only specific to precision grasp. However, a main difference with precision grasping was that modulation of digit position to the object’s mass distribution was driven predominantly by the thumb, with little to no modulation of finger position. Modulation of thumb position rather than fingers is likely due to its greater range of motion and therefore adaptability to object properties. Our results underscore the flexibility of the central nervous system in implementing a range of solutions along the digit force-to-position continuum for dexterous manipulation.

  9. Attenuated food anticipatory activity and abnormal circadian locomotor rhythms in Rgs16 knockdown mice.

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    Naoto Hayasaka

    Full Text Available Regulators of G protein signaling (RGS are a multi-functional protein family, which functions in part as GTPase-activating proteins (GAPs of G protein α-subunits to terminate G protein signaling. Previous studies have demonstrated that the Rgs16 transcripts exhibit robust circadian rhythms both in the suprachiasmatic nucleus (SCN, the master circadian light-entrainable oscillator (LEO of the hypothalamus, and in the liver. To investigate the role of RGS16 in the circadian clock in vivo, we generated two independent transgenic mouse lines using lentiviral vectors expressing short hairpin RNA (shRNA targeting the Rgs16 mRNA. The knockdown mice demonstrated significantly shorter free-running period of locomotor activity rhythms and reduced total activity as compared to the wild-type siblings. In addition, when feeding was restricted during the daytime, food-entrainable oscillator (FEO-driven elevated food-anticipatory activity (FAA observed prior to the scheduled feeding time was significantly attenuated in the knockdown mice. Whereas the restricted feeding phase-advanced the rhythmic expression of the Per2 clock gene in liver and thalamus in the wild-type animals, the above phase shift was not observed in the knockdown mice. This is the first in vivo demonstration that a common regulator of G protein signaling is involved in the two separate, but interactive circadian timing systems, LEO and FEO. The present study also suggests that liver and/or thalamus regulate the food-entrained circadian behavior through G protein-mediated signal transduction pathway(s.

  10. Synchronization of PER1 protein in Parabrachial nucleus in a natural model of food anticipatory activity

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    Juárez, Claudia; Morgado, Elvira; Waliszewski, Stefan M.; Martínez, Armando J.; Meza, Enrique; Caba, Mario

    2012-01-01

    Rabbit pups represent a natural model of food anticipatory activity (FAA). FAA is the behavioral output of a putative food entrainable oscillator (FEO). It had been suggested that the FEO is comprised of a distributed system of clocks that work in concert in response to gastrointestinal input by food. Scheduled food intake synchronizes several nuclei in the brain, and the hypothalamus has received particular attention. On the contrary, brainstem nuclei, despite being among the brain structures to first receive food cues, have been scarcely studied. Here we analyzed by immunohistochemistry possible oscillation of FOS and PER1 proteins through a complete 24 h cycle in the dorsal vagal complex (DVC) and parabrachial nucleus (PBN) of seven to eight day old rabbit pups scheduled to nurse during the night (02:00) or day (10:00) and also in fasted subjects to explore the possible persistence of oscillations. We found a clear induction of FOS that peaks 1.5 h after nursing in all nuclei studied. PER1 was only synchronized in the PBN, reaching highest values 12 h after nursing. Only PER1 oscillations persisted in fasted subjects. We conclude that the DVC nuclei are probably more related to the transmission of food cues to other brain regions but that the PBN participates in the integration of information essential for FAA. Our results support previous findings suggesting that the DVC nuclei, but not PBN, are not essential for FAA. We suggest that PBN is a key component of the proposed distributed system of clocks involved in FAA. PMID:22471601

  11. Adaptation to short photoperiods augments circadian food anticipatory activity in Siberian hamsters.

    Science.gov (United States)

    Bradley, Sean P; Prendergast, Brian J

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5h interval of the light phase. Running wheel activity occurring within a 3h window immediately prior to actual or anticipated food delivery was operationally-defined as food anticipatory activity (FAA). After the timed-feeding interval, hamsters were fed ad libitum, and FAA was assessed 2 and 7 days later via probe trials of total food deprivation. During timed-feeding, all hamsters exhibited increases FAA, but FAA emerged more rapidly in SD; in probe trials, FAA was greater in magnitude and persistence in SD. Gonadectomy in LD did not induce the SD-like FAA phenotype, indicating that withdrawal of gonadal hormones is not sufficient to mediate the effects of photoperiod on FAA. Entrainment of the circadian system to light markedly affects the functional output of the FEO via gonadal hormone-independent mechanisms. Rapid emergence and persistent expression of FAA in SD may reflect a seasonal adaptation that directs behavior toward sources of nutrition with high temporal precision at times of year when food is scarce.

  12. Synchronization of PER1 protein in parabrachial nucleus in a natural model of food anticipatory activity.

    Science.gov (United States)

    Juárez, Claudia; Morgado, Elvira; Waliszewski, Stefan M; Martínez, Armando J; Meza, Enrique; Caba, Mario

    2012-05-01

    Rabbit pups represent a natural model of food anticipatory activity (FAA). FAA is the behavioral output of a putative food entrainable oscillator (FEO). It had been suggested that the FEO is comprised of a distributed system of clocks that work in concert in response to gastrointestinal input by food. Scheduled food intake synchronizes several nuclei in the brain, and the hypothalamus has received particular attention. On the contrary, brainstem nuclei, despite being among the brain structures to first receive food cues, have been scarcely studied. Here we analysed by immunohistochemistry possible oscillation of FOS and PER1 proteins through a complete 24-h cycle in the dorsal vagal complex (DVC) and parabrachial nucleus (PBN) of 7-8-day-old rabbit pups scheduled to nurse during the night (02:00 h) or day (10:00 h), and also in fasted subjects to explore the possible persistence of oscillations. We found a clear induction of FOS that peaks 1.5 h after nursing in all nuclei studied. PER1 was only synchronized in the PBN, reaching highest values 12 h after nursing. Only PER1 oscillations persisted, with a shift, in fasted subjects. We conclude that the DVC nuclei are probably more related to the transmission of food cues to other brain regions, but that the PBN participates in the integration of information essential for FAA. Our results support previous findings suggesting that the DVC nuclei, but not PBN, are not essential for FAA. We suggest that PBN is a key component of the proposed distributed system of clocks involved in FAA.

  13. Contribution of supraspinal systems to generation of automatic postural responses

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    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.

  14. 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.

  15. Effect of Neck Muscle Strength and Anticipatory Cervical Muscle Activation on the Kinematic Response of the Head to Impulsive Loads

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    Eckner, James T.; Oh, Youkeun K.; Joshi, Monica S.; Richardson, James K.; Ashton-Miller, James A.

    2015-01-01

    Background Greater neck strength and activating the neck muscles to brace for impact are both thought to reduce an athlete's risk of concussion during a collision by attenuating the head's kinematic response after impact. However, the literature reporting the neck's role in controlling postimpact head kinematics is mixed. Furthermore, these relationships have not been examined in the coronal or transverse planes or in pediatric athletes. Hypotheses In each anatomic plane, peak linear velocity (DV) and peak angular velocity (Dv) of the head are inversely related to maximal isometric cervical muscle strength in the opposing direction (H1). Under impulsive loading, DV and Dv will be decreased during anticipatory cervical muscle activation compared with the baseline state (H2). Study Design Descriptive laboratory study. Methods Maximum isometric neck strength was measured in each anatomic plane in 46 male and female contact sport athletes aged 8 to 30 years. A loading apparatus applied impulsive test forces to athletes' heads in flexion, extension, lateral flexion, and axial rotation during baseline and anticipatory cervical muscle activation conditions. Multivariate linear mixed models were used to determine the effects of neck strength and cervical muscle activation on head DV and Dv. Results Greater isometric neck strength and anticipatory activation were independently associated with decreased head DV and Dv after impulsive loading across all planes of motion (all P\\.001). Inverse relationships between neck strength and head DV and Dv presented moderately strong effect sizes (r = 0.417 to r = 0.657), varying by direction of motion and cervical muscle activation. Conclusion In male and female athletes across the age spectrum, greater neck strength and anticipatory cervical muscle activation (“bracing for impact”) can reduce the magnitude of the head's kinematic response. Future studies should determine whether neck strength contributes to the observed sex and

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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

  9. Evaluation of the autonomic neuropathy function immediately after a change to upright posture using the impulse response function; Impulse oto kansu wo mochiita shisei henkan katoki ni okeru jiritsu shinkei kino hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, K. [Nagoya City University, Nagoya (Japan); Moyoshi, M.; Takata, K. [Daido Institute of Technology, Nagoya (Japan); Watanabe, Y. [Toyota College of Technology, Aichi (Japan)

    1997-05-20

    Autonomic neuropathy function immediately after a change to upright posture has been evaluated by applying transient response function of the system to the blood regulation system. The impulse response function was determined from the change in heart rate before postural change to the upright posture, and was compared with the transient change immediately after a change to the upright posture. The time series of R-R interval of electrocardiogram was used as the time series of the change in heart rate. To determine the impulse response function, an autoregressive model was applied to the R-R interval time series. The impulse response function at the steady state is a transient reaction at the impulse stimulation added to the blood regulation system. The R-R interval decreases rapidly by the autonomic neuropathy reaction in which the blood is rapidly transferred into the legs immediately after a change to upright posture. There is a close correlation between the initial temporary decrease in R-R interval and the impulse response function derived from the change in heart rate immediately after a change to the upright posture. Accordingly, the blood regulation and autonomic neuropathy functions can be evaluated by the impulse response function without actual standing test and load of tested persons. 9 refs., 3 figs., 1 tab.

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. 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.

  16. Design of strategies to assess lumbar posture during work.

    NARCIS (Netherlands)

    Burdorf, A.; Riel, van M.

    1996-01-01

    Quantitative characterization of postural load on the back should describe exposure patterns among workers and factors affecting these exposure patterns. This article presents general guidelines for designing appropriate measurement strategies; how to obtain detailed data with an applicable measurem

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

    Directory of Open Access Journals (Sweden)

    Porto EF

    2015-06-01

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

  18. The Communication of Meaning in Anticipat