Imitation of Body Postures and Hand Movements in Children with Specific Language Impairment

Science.gov (United States)

Marton, Klara

2009-01-01

Within the domain-general theory of language impairment, this study examined body posture and hand movement imitation in children with specific language impairment (SLI) and in their age-matched peers. Participants included 40 children with SLI (5 years 3 months to 6 years 10 months of age) and 40 children with typical language development (5…

Upper Limb Posture Estimation in Robotic and Virtual Reality-Based Rehabilitation

Science.gov (United States)

Cortés, Camilo; Ardanza, Aitor; Molina-Rueda, F.; Cuesta-Gómez, A.; Ruiz, Oscar E.

2014-01-01

New motor rehabilitation therapies include virtual reality (VR) and robotic technologies. In limb rehabilitation, limb posture is required to (1) provide a limb realistic representation in VR games and (2) assess the patient improvement. When exoskeleton devices are used in the therapy, the measurements of their joint angles cannot be directly used to represent the posture of the patient limb, since the human and exoskeleton kinematic models differ. In response to this shortcoming, we propose a method to estimate the posture of the human limb attached to the exoskeleton. We use the exoskeleton joint angles measurements and the constraints of the exoskeleton on the limb to estimate the human limb joints angles. This paper presents (a) the mathematical formulation and solution to the problem, (b) the implementation of the proposed solution on a commercial exoskeleton system for the upper limb rehabilitation, (c) its integration into a rehabilitation VR game platform, and (d) the quantitative assessment of the method during elbow and wrist analytic training. Results show that this method properly estimates the limb posture to (i) animate avatars that represent the patient in VR games and (ii) obtain kinematic data for the patient assessment during elbow and wrist analytic rehabilitation. PMID:25110698

Upper Limb Posture Estimation in Robotic and Virtual Reality-Based Rehabilitation

Directory of Open Access Journals (Sweden)

Camilo Cortés

2014-01-01

Full Text Available New motor rehabilitation therapies include virtual reality (VR and robotic technologies. In limb rehabilitation, limb posture is required to (1 provide a limb realistic representation in VR games and (2 assess the patient improvement. When exoskeleton devices are used in the therapy, the measurements of their joint angles cannot be directly used to represent the posture of the patient limb, since the human and exoskeleton kinematic models differ. In response to this shortcoming, we propose a method to estimate the posture of the human limb attached to the exoskeleton. We use the exoskeleton joint angles measurements and the constraints of the exoskeleton on the limb to estimate the human limb joints angles. This paper presents (a the mathematical formulation and solution to the problem, (b the implementation of the proposed solution on a commercial exoskeleton system for the upper limb rehabilitation, (c its integration into a rehabilitation VR game platform, and (d the quantitative assessment of the method during elbow and wrist analytic training. Results show that this method properly estimates the limb posture to (i animate avatars that represent the patient in VR games and (ii obtain kinematic data for the patient assessment during elbow and wrist analytic rehabilitation.

Compensatory motor control after stroke: an alternative joint strategy for object-dependent shaping of hand posture.

Science.gov (United States)

Raghavan, Preeti; Santello, Marco; Gordon, Andrew M; Krakauer, John W

2010-06-01

Efficient grasping requires planned and accurate coordination of finger movements to approximate the shape of an object before contact. In healthy subjects, hand shaping is known to occur early in reach under predominantly feedforward control. In patients with hemiparesis after stroke, execution of coordinated digit motion during grasping is impaired as a result of damage to the corticospinal tract. The question addressed here is whether patients with hemiparesis are able to compensate for their execution deficit with a qualitatively different grasp strategy that still allows them to differentiate hand posture to object shape. Subjects grasped a rectangular, concave, and convex object while wearing an instrumented glove. Reach-to-grasp was divided into three phases based on wrist kinematics: reach acceleration (reach onset to peak horizontal wrist velocity), reach deceleration (peak horizontal wrist velocity to reach offset), and grasp (reach offset to lift-off). Patients showed reduced finger abduction, proximal interphalangeal joint (PIP) flexion, and metacarpophalangeal joint (MCP) extension at object grasp across all three shapes compared with controls; however, they were able to partially differentiate hand posture for the convex and concave shapes using a compensatory strategy that involved increased MCP flexion rather than the PIP flexion seen in controls. Interestingly, shape-specific hand postures did not unfold initially during reach acceleration as seen in controls, but instead evolved later during reach deceleration, which suggests increased reliance on sensory feedback. These results indicate that kinematic analysis can identify and quantify within-limb compensatory motor control strategies after stroke. From a clinical perspective, quantitative study of compensation is important to better understand the process of recovery from brain injury. From a motor control perspective, compensation can be considered a model for how joint redundancy is exploited

Unimanual SNARC Effect: Hand Matters

Directory of Open Access Journals (Sweden)

Marianna eRiello

2011-12-01

Full Text Available A structural representation of the hand embedding information about the identity and relative position of fingers is necessary to counting routines. It may also support associations between numbers and allocentric spatial codes that predictably interact with other known numerical spatial representations, such as the mental number line. In this study, 48 Western participants whose typical counting routine proceeded from thumb-to-little on both hands performed magnitude and parity binary judgments. Response keys were pressed either with the right index and middle fingers or with the left index and middle fingers in separate blocks. 24 participants responded with either hands in prone posture (i.e. palm down and 24 participants responded with either hands in supine (i.e. palm up posture. When hands were in prone posture, the counting direction of the left hand conflicted with the direction of the left-right mental number line, whereas the counting direction of the right hand was consistent with it. When hands were in supine posture, the opposite was true. If systematic associations existed between relative number magnitude and an allocentric spatial representation of the finger series within each hand, as predicted on the basis of counting habits, interactions would be expected between hand posture and a unimanual version of the Spatial-Numerical Association of Response Codes (SNARC effect. Data revealed that with hands in prone posture a unimanual SNARC effect was present for the right hand, and with hands in supine posture a unimanual SNARC effect was present for the left hand. We propose that a posture-invariant body structural representation of the finger series provides a relevant frame of reference, a within-hand directional vector, that is associated to simple number processing. Such frame of reference can significantly interact with stimulus-response correspondence effects that have been attributed to the mapping of numbers on a mental

Learning Is Better with the Hands Free: The Role of Posture in the Memory of Manipulable Objects.

Directory of Open Access Journals (Sweden)

Léo Dutriaux

Full Text Available Grounded cognition proposes that memory shares processing resources with sensorimotor systems. The aim of the present study was to show that motor simulation participates in the conceptual representation of manipulable objects in long-term memory. In two experiments, lists of manipulable and nonmanipulable objects were presented. Participants were instructed to memorize the items while adopting different postures. In the control condition, they had to keep their hands at rest in front of them. In the interference condition, participants had to keep their hands crossed behind their back to make their hands less free for action. After each list, participants had to perform first a distractive task, and then an oral free recall. The results showed that the interfering posture produced a specific decrease in the recall of manipulable objects, but not of nonmanipulable ones. This decrease was similar when the items were presented as pictures (Experiment 1 or as words (Experiment 2, thus excluding a purely visual effect. These results provide strong evidence that the motor simulation plays a role in the memory trace of the object.

Learning Is Better with the Hands Free: The Role of Posture in the Memory of Manipulable Objects.

Science.gov (United States)

Dutriaux, Léo; Gyselinck, Valérie

2016-01-01

Grounded cognition proposes that memory shares processing resources with sensorimotor systems. The aim of the present study was to show that motor simulation participates in the conceptual representation of manipulable objects in long-term memory. In two experiments, lists of manipulable and nonmanipulable objects were presented. Participants were instructed to memorize the items while adopting different postures. In the control condition, they had to keep their hands at rest in front of them. In the interference condition, participants had to keep their hands crossed behind their back to make their hands less free for action. After each list, participants had to perform first a distractive task, and then an oral free recall. The results showed that the interfering posture produced a specific decrease in the recall of manipulable objects, but not of nonmanipulable ones. This decrease was similar when the items were presented as pictures (Experiment 1) or as words (Experiment 2), thus excluding a purely visual effect. These results provide strong evidence that the motor simulation plays a role in the memory trace of the object.

Unimanual SNARC Effect: Hand Matters.

Science.gov (United States)

Riello, Marianna; Rusconi, Elena

2011-01-01

A structural representation of the hand embedding information about the identity and relative position of fingers is necessary to counting routines. It may also support associations between numbers and allocentric spatial codes that predictably interact with other known numerical spatial representations, such as the mental number line (MNL). In this study, 48 Western participants whose typical counting routine proceeded from thumb-to-little on both hands performed magnitude and parity binary judgments. Response keys were pressed either with the right index and middle fingers or with the left index and middle fingers in separate blocks. 24 participants responded with either hands in prone posture (i.e., palm down) and 24 participants responded with either hands in supine (i.e., palm up) posture. When hands were in prone posture, the counting direction of the left hand conflicted with the direction of the left-right MNL, whereas the counting direction of the right hand was consistent with it. When hands were in supine posture, the opposite was true. If systematic associations existed between relative number magnitude and an allocentric spatial representation of the finger series within each hand, as predicted on the basis of counting habits, interactions would be expected between hand posture and a unimanual version of the spatial-numerical association of response codes (SNARC) effect. Data revealed that with hands in prone posture a unimanual SNARC effect was present for the right hand, and with hands in supine posture a unimanual SNARC effect was present for the left hand. We propose that a posture-invariant body structural representation of the finger series provides a relevant frame of reference, a within-hand directional vector, that is associated to simple number processing. Such frame of reference can significantly interact with stimulus-response correspondence effects, like the SNARC, that have been typically attributed to the mapping of numbers on a left

Upper Limb-Hand 3D Display System for Biomimetic Myoelectric Hand Simulator

National Research Council Canada - National Science Library

Jimenez, Gonzalo

2001-01-01

A graphics system displaying both upper limb posture and opening-closing of a prosthetic hand was developed for realtime operation of our biomimetic myoelectric hand simulator, Posture of the upper...

SAR target recognition and posture estimation using spatial pyramid pooling within CNN

Science.gov (United States)

Peng, Lijiang; Liu, Xiaohua; Liu, Ming; Dong, Liquan; Hui, Mei; Zhao, Yuejin

2018-01-01

Many convolution neural networks(CNN) architectures have been proposed to strengthen the performance on synthetic aperture radar automatic target recognition (SAR-ATR) and obtained state-of-art results on targets classification on MSTAR database, but few methods concern about the estimation of depression angle and azimuth angle of targets. To get better effect on learning representation of hierarchies of features on both 10-class target classification task and target posture estimation tasks, we propose a new CNN architecture with spatial pyramid pooling(SPP) which can build high hierarchy of features map by dividing the convolved feature maps from finer to coarser levels to aggregate local features of SAR images. Experimental results on MSTAR database show that the proposed architecture can get high recognition accuracy as 99.57% on 10-class target classification task as the most current state-of-art methods, and also get excellent performance on target posture estimation tasks which pays attention to depression angle variety and azimuth angle variety. What's more, the results inspire us the application of deep learning on SAR target posture description.

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

Directory of Open Access Journals (Sweden)

Jernej Camernik

2016-09-01

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

Impaired hand size estimation in CRPS.

Science.gov (United States)

Peltz, Elena; Seifert, Frank; Lanz, Stefan; Müller, Rüdiger; Maihöfner, Christian

2011-10-01

A triad of clinical symptoms, ie, autonomic, motor and sensory dysfunctions, characterizes complex regional pain syndromes (CRPS). Sensory dysfunction comprises sensory loss or spontaneous and stimulus-evoked pain. Furthermore, a disturbance in the body schema may occur. In the present study, patients with CRPS of the upper extremity and healthy controls estimated their hand sizes on the basis of expanded or compressed schematic drawings of hands. In patients with CRPS we found an impairment in accurate hand size estimation; patients estimated their own CRPS-affected hand to be larger than it actually was when measured objectively. Moreover, overestimation correlated significantly with disease duration, neglect score, and increase of two-point-discrimination-thresholds (TPDT) compared to the unaffected hand and to control subjects' estimations. In line with previous functional imaging studies in CRPS patients demonstrating changes in central somatotopic maps, we suggest an involvement of the central nervous system in this disruption of the body schema. Potential cortical areas may be the primary somatosensory and posterior parietal cortices, which have been proposed to play a critical role in integrating visuospatial information. CRPS patients perceive their affected hand to be bigger than it is. The magnitude of this overestimation correlates with disease duration, decreased tactile thresholds, and neglect-score. Suggesting a disrupted body schema as the source of this impairment, our findings corroborate the current assumption of a CNS involvement in CRPS. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

Trabecular bone structure correlates with hand posture and use in hominoids.

Directory of Open Access Journals (Sweden)

Zewdi J Tsegai

Full Text Available Bone is capable of adapting during life in response to stress. Therefore, variation in locomotor and manipulative behaviours across extant hominoids may be reflected in differences in trabecular bone structure. The hand is a promising region for trabecular analysis, as it is the direct contact between the individual and the environment and joint positions at peak loading vary amongst extant hominoids. Building upon traditional volume of interest-based analyses, we apply a whole-epiphysis analytical approach using high-resolution microtomographic scans of the hominoid third metacarpal to investigate whether trabecular structure reflects differences in hand posture and loading in knuckle-walking (Gorilla, Pan, suspensory (Pongo, Hylobates and Symphalangus and manipulative (Homo taxa. Additionally, a comparative phylogenetic method was used to analyse rates of evolutionary changes in trabecular parameters. Results demonstrate that trabecular bone volume distribution and regions of greatest stiffness (i.e., Young's modulus correspond with predicted loading of the hand in each behavioural category. In suspensory and manipulative taxa, regions of high bone volume and greatest stiffness are concentrated on the palmar or distopalmar regions of the metacarpal head, whereas knuckle-walking taxa show greater bone volume and stiffness throughout the head, and particularly in the dorsal region; patterns that correspond with the highest predicted joint reaction forces. Trabecular structure in knuckle-walking taxa is characterised by high bone volume fraction and a high degree of anisotropy in contrast to the suspensory brachiators. Humans, in which the hand is used primarily for manipulation, have a low bone volume fraction and a variable degree of anisotropy. Finally, when trabecular parameters are mapped onto a molecular-based phylogeny, we show that the rates of change in trabecular structure vary across the hominoid clade. Our results support a link

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.

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

Science.gov (United States)

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

2014-03-01

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

Hand Grasping Synergies As Biometrics.

Science.gov (United States)

Patel, Vrajeshri; Thukral, Poojita; Burns, Martin K; Florescu, Ionut; Chandramouli, Rajarathnam; Vinjamuri, Ramana

2017-01-01

Recently, the need for more secure identity verification systems has driven researchers to explore other sources of biometrics. This includes iris patterns, palm print, hand geometry, facial recognition, and movement patterns (hand motion, gait, and eye movements). Identity verification systems may benefit from the complexity of human movement that integrates multiple levels of control (neural, muscular, and kinematic). Using principal component analysis, we extracted spatiotemporal hand synergies (movement synergies) from an object grasping dataset to explore their use as a potential biometric. These movement synergies are in the form of joint angular velocity profiles of 10 joints. We explored the effect of joint type, digit, number of objects, and grasp type. In its best configuration, movement synergies achieved an equal error rate of 8.19%. While movement synergies can be integrated into an identity verification system with motion capture ability, we also explored a camera-ready version of hand synergies-postural synergies. In this proof of concept system, postural synergies performed well, but only when specific postures were chosen. Based on these results, hand synergies show promise as a potential biometric that can be combined with other hand-based biometrics for improved security.

Hand Grasping Synergies As Biometrics

Directory of Open Access Journals (Sweden)

Ramana Vinjamuri

2017-05-01

Full Text Available Recently, the need for more secure identity verification systems has driven researchers to explore other sources of biometrics. This includes iris patterns, palm print, hand geometry, facial recognition, and movement patterns (hand motion, gait, and eye movements. Identity verification systems may benefit from the complexity of human movement that integrates multiple levels of control (neural, muscular, and kinematic. Using principal component analysis, we extracted spatiotemporal hand synergies (movement synergies from an object grasping dataset to explore their use as a potential biometric. These movement synergies are in the form of joint angular velocity profiles of 10 joints. We explored the effect of joint type, digit, number of objects, and grasp type. In its best configuration, movement synergies achieved an equal error rate of 8.19%. While movement synergies can be integrated into an identity verification system with motion capture ability, we also explored a camera-ready version of hand synergies—postural synergies. In this proof of concept system, postural synergies performed well, but only when specific postures were chosen. Based on these results, hand synergies show promise as a potential biometric that can be combined with other hand-based biometrics for improved security.

The dentist’s operating posture – ergonomic aspects

Science.gov (United States)

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

2014-01-01

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

Effects of hand orientation on motor imagery--event related potentials suggest kinesthetic motor imagery to solve the hand laterality judgment task.

Science.gov (United States)

Jongsma, Marijtje L A; Meulenbroek, Ruud G J; Okely, Judith; Baas, C Marjolein; van der Lubbe, Rob H J; Steenbergen, Bert

2013-01-01

Motor imagery (MI) refers to the process of imagining the execution of a specific motor action without actually producing an overt movement. Two forms of MI have been distinguished: visual MI and kinesthetic MI. To distinguish between these forms of MI we employed an event related potential (ERP) study to measure interference effects induced by hand orientation manipulations in a hand laterality judgement task. We hypothesized that this manipulation should only affect kinesthetic MI but not visual MI. The ERPs elicited by rotated hand stimuli contained the classic rotation related negativity (RRN) with respect to palm view stimuli. We observed that laterally rotated stimuli led to a more marked RRN than medially rotated stimuli. This RRN effect was observed when participants had their hands positioned in either a straight (control) or an inward rotated posture, but not when their hands were positioned in an outward rotated posture. Posture effects on the ERP-RRN have not previously been studied. Apparently, a congruent hand posture (hands positioned in an outward rotated fashion) facilitates the judgement of the otherwise more demanding laterally rotated hand stimuli. These ERP findings support a kinesthetic interpretation of MI involved in solving the hand laterality judgement task. The RRN may be used as a non-invasive marker for kinesthetic MI and seems useful in revealing the covert behavior of MI in e.g. rehabilitation programs.

Thoracic posture, shoulder muscle activation patterns and isokinetic ...

African Journals Online (AJOL)

Poor posture, scapular dyskinesia, altered scapular muscle recruitment patterns and ... postural deviation and incorrect shoulder kinematics.[5]. Knowledge of the .... the contra-lateral hand was placed as far down the spinal column as possible, and the ... produced by muscle contraction for rotation around a joint.[12] During.

Integration of robotics and neuroscience beyond the hand: What kind of synergies?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

Science.gov (United States)

d'Avella, Andrea

2016-07-01

Santello et al. [1] review an impressive amount of work on the control of biological and artificial hands that demonstrates how the concept of synergies can lead to a successful integration of robotics and neuroscience. Is it possible to generalize the same approach to the control of biological and artificial limbs and bodies beyond the hand? The human hand synergies that appear most relevant for robotic hands are those defined at the kinematic level, i.e. postural synergies [2]. Postural synergies capture the geometric relations among the many joints of the hand and allow for a low dimensional characterization and synthesis of the static hand postures involved in grasping and manipulating a large set of objects. However, many other complex motor skills such as walking, reaching, throwing, and catching require controlling multi-articular time-varying trajectories rather than static postures. Dynamic control of biological and artificial limbs and bodies, especially when geometric and inertial parameters are uncertain and the joints are compliant, poses great challenges. What kind of synergies might simplify the dynamic control of motor skills involving upper and lower limbs as well as the whole body?

Computational intelligence in multi-feature visual pattern recognition hand posture and face recognition using biologically inspired approaches

CERN Document Server

Pisharady, Pramod Kumar; Poh, Loh Ai

2014-01-01

This book presents a collection of computational intelligence algorithms that addresses issues in visual pattern recognition such as high computational complexity, abundance of pattern features, sensitivity to size and shape variations and poor performance against complex backgrounds. The book has 3 parts. Part 1 describes various research issues in the field with a survey of the related literature. Part 2 presents computational intelligence based algorithms for feature selection and classification. The algorithms are discriminative and fast. The main application area considered is hand posture recognition. The book also discusses utility of these algorithms in other visual as well as non-visual pattern recognition tasks including face recognition, general object recognition and cancer / tumor classification. Part 3 presents biologically inspired algorithms for feature extraction. The visual cortex model based features discussed have invariance with respect to appearance and size of the hand, and provide good...

A synergy-based hand control is encoded in human motor cortical areas

Science.gov (United States)

Leo, Andrea; Handjaras, Giacomo; Bianchi, Matteo; Marino, Hamal; Gabiccini, Marco; Guidi, Andrea; Scilingo, Enzo Pasquale; Pietrini, Pietro; Bicchi, Antonio; Santello, Marco; Ricciardi, Emiliano

2016-01-01

How the human brain controls hand movements to carry out different tasks is still debated. The concept of synergy has been proposed to indicate functional modules that may simplify the control of hand postures by simultaneously recruiting sets of muscles and joints. However, whether and to what extent synergic hand postures are encoded as such at a cortical level remains unknown. Here, we combined kinematic, electromyography, and brain activity measures obtained by functional magnetic resonance imaging while subjects performed a variety of movements towards virtual objects. Hand postural information, encoded through kinematic synergies, were represented in cortical areas devoted to hand motor control and successfully discriminated individual grasping movements, significantly outperforming alternative somatotopic or muscle-based models. Importantly, hand postural synergies were predicted by neural activation patterns within primary motor cortex. These findings support a novel cortical organization for hand movement control and open potential applications for brain-computer interfaces and neuroprostheses. DOI: http://dx.doi.org/10.7554/eLife.13420.001 PMID:26880543

Additional Haptic Information Provided by Anchors Reduces Postural Sway in Young Adults Less Than Does Light Touch

Directory of Open Access Journals (Sweden)

Renato Moraes

2018-06-01

Full Text Available This study investigated the effect of adding haptic information to the control of posture, as well as comparing the effect of both the “light touch” (LT and “anchor system” (AS paradigms on postural sway. Additionally, it compared the effect of location and number of points of contact to the control of posture in young adults. The location consisted of using the anchors tied to the finger and held by the hands, and, for LT, the fingertip. For the number of points of contact, participants used two hands, and then separately the dominant hand, and the non-dominant hand, for both anchor and LT paradigms. Participants stood upright with feet-together and in tandem position while performing tasks that combined the use of anchors and LT, points of contact (hand grip and finger, and number of points of contact (two hands and one hand. In this study, the anchors consist of holding in each hand a flexible cable with the other end attached to the ground. The LT consists of slightly touching a rigid surface with the tip of the index finger. The results showed, first, that the anchors improved postural control less than did the LT. Second, they revealed that holding the anchors with the hands or with them tied to the fingertip resulted in a similar reduction in postural sway only in the tandem position. For the feet-together position, the anchors tied to the fingertip were ineffective. Similarly, the use of one or two hands did not affect the contribution of the anchors. However, using two hands in the LT condition was more effective than was one hand. Third, our results showed the presence of a temporal delay between force and center-of-pressure (COP for the anchors, only in the AP direction with feet-together. In conclusion, overall, the anchors were less effective in reducing postural sway than was the LT. The anchors attached to fingertips were as effective as the hand-held anchors in the tandem position, yet ineffective during foot

Postural Effects on the Mental Rotation of Body-Related Pictures: An fMRI Study

Directory of Open Access Journals (Sweden)

Fangbing Qu

2018-05-01

Full Text Available This study investigated the embodied effects involved in the mental rotation of pictures of body parts (hands and feet. Blood oxygen level-dependent (BOLD signals were collected from 18 healthy volunteers who performed mental rotation tasks of rotated drawings of hands under different arm postures. Congruent drawings of hands (those congruent with left-hand posture evoked stronger activation in the left supplementary motor area (SMA, left precentral gyrus, and left superior parietal lobule (SPL than did incongruent drawings of hands. Congruent drawings of hands (those congruent with right-hand posture evoked significant activation in the left inferior parietal lobule (IPL, right SMA, bilateral middle frontal gyrus (MFG, left inferior frontal gyrus (IFG, and bilateral superior frontal gyrus (SFG compared to that evoked by the incongruent drawings of hands. Similar methodology was implemented with drawings of feet. However, no significant differences in brain activation were observed between congruent and incongruent drawings of feet. This finding suggests that body posture influences body part-related mental rotation in an effector-specific manner. A direct comparison between the medially and laterally rotated drawings revealed activation in the right IPL, left precentral gyrus, bilateral IFG, and bilateral SFG. These results suggest that biomechanical constraints affect the cognitive process of mental rotation.

Estimation of stature from hand impression: a nonconventional approach.

Science.gov (United States)

Ahemad, Nasir; Purkait, Ruma

2011-05-01

Stature is used for constructing a biological profile that assists with the identification of an individual. So far, little attention has been paid to the fact that stature can be estimated from hand impressions left at scene of crime. The present study based on practical observations adopted a new methodology of measuring hand length from the depressed area between hypothenar and thenar region on the proximal surface of the palm. Stature and bilateral hand impressions were obtained from 503 men of central India. Seventeen dimensions of hand were measured on the impression. Linear regression equations derived showed hand length followed by palm length are best estimates of stature. Testing the practical utility of the suggested method on latent prints of 137 subjects, a statistically insignificant result was obtained when known and estimated stature derived from latent prints was compared. The suggested approach points to a strong possibility of its usage in crime scene investigation, albeit the fact that validation studies in real-life scenarios are performed. © 2011 American Academy of Forensic Sciences.

Rubber hand illusion affects joint angle perception.

Directory of Open Access Journals (Sweden)

Martin V Butz

Full Text Available The Rubber Hand Illusion (RHI is a well-established experimental paradigm. It has been shown that the RHI can affect hand location estimates, arm and hand motion towards goals, the subjective visual appearance of the own hand, and the feeling of body ownership. Several studies also indicate that the peri-hand space is partially remapped around the rubber hand. Nonetheless, the question remains if and to what extent the RHI can affect the perception of other body parts. In this study we ask if the RHI can alter the perception of the elbow joint. Participants had to adjust an angular representation on a screen according to their proprioceptive perception of their own elbow joint angle. The results show that the RHI does indeed alter the elbow joint estimation, increasing the agreement with the position and orientation of the artificial hand. Thus, the results show that the brain does not only adjust the perception of the hand in body-relative space, but it also modifies the perception of other body parts. In conclusion, we propose that the brain continuously strives to maintain a consistent internal body image and that this image can be influenced by the available sensory information sources, which are mediated and mapped onto each other by means of a postural, kinematic body model.

Hand-to-Hand Model for Bioelectrical Impedance Analysis to Estimate Fat Free Mass in a Healthy Population

Directory of Open Access Journals (Sweden)

Hsueh-Kuan Lu

2016-10-01

Full Text Available This study aimed to establish a hand-to-hand (HH model for bioelectrical impedance analysis (BIA fat free mass (FFM estimation by comparing with a standing position hand-to-foot (HF BIA model and dual energy X-ray absorptiometry (DXA; we also verified the reliability of the newly developed model. A total of 704 healthy Chinese individuals (403 men and 301 women participated. FFM (FFMDXA reference variables were measured using DXA and segmental BIA. Further, regression analysis, Bland–Altman plots, and cross-validation (2/3 participants as the modeling group, 1/3 as the validation group; three turns were repeated for validation grouping were conducted to compare tests of agreement with FFMDXA reference variables. In male participants, the hand-to-hand BIA model estimation equation was calculated as follows: FFMmHH = 0.537 h2/ZHH − 0.126 year + 0.217 weight + 18.235 (r2 = 0.919, standard estimate of error (SEE = 2.164 kg, n = 269. The mean validated correlation coefficients and limits of agreement (LOAs of the Bland–Altman analysis of the calculated values for FFMmHH and FFMDXA were 0.958 and −4.369–4.343 kg, respectively, for hand-to-foot BIA model measurements for men; the FFM (FFMmHF and FFMDXA were 0.958 and −4.356–4.375 kg, respectively. The hand-to-hand BIA model estimating equation for female participants was FFMFHH = 0.615 h2/ZHH − 0.144 year + 0.132 weight + 16.507 (r2 = 0.870, SEE = 1.884 kg, n = 201; the three mean validated correlation coefficient and LOA for the hand-to-foot BIA model measurements for female participants (FFMFHH and FFMDXA were 0.929 and −3.880–3.886 kg, respectively. The FFMHF and FFMDXA were 0.942 and −3.511–3.489 kg, respectively. The results of both hand-to-hand and hand-to-foot BIA models demonstrated similar reliability, and the hand-to-hand BIA models are practical for assessing FFM.

Hand-to-Hand Model for Bioelectrical Impedance Analysis to Estimate Fat Free Mass in a Healthy Population.

Science.gov (United States)

Lu, Hsueh-Kuan; Chiang, Li-Ming; Chen, Yu-Yawn; Chuang, Chih-Lin; Chen, Kuen-Tsann; Dwyer, Gregory B; Hsu, Ying-Lin; Chen, Chun-Hao; Hsieh, Kuen-Chang

2016-10-21

This study aimed to establish a hand-to-hand (HH) model for bioelectrical impedance analysis (BIA) fat free mass (FFM) estimation by comparing with a standing position hand-to-foot (HF) BIA model and dual energy X-ray absorptiometry (DXA); we also verified the reliability of the newly developed model. A total of 704 healthy Chinese individuals (403 men and 301 women) participated. FFM (FFM DXA ) reference variables were measured using DXA and segmental BIA. Further, regression analysis, Bland-Altman plots, and cross-validation (2/3 participants as the modeling group, 1/3 as the validation group; three turns were repeated for validation grouping) were conducted to compare tests of agreement with FFM DXA reference variables. In male participants, the hand-to-hand BIA model estimation equation was calculated as follows: FFM m HH = 0.537 h²/Z HH - 0.126 year + 0.217 weight + 18.235 ( r ² = 0.919, standard estimate of error (SEE) = 2.164 kg, n = 269). The mean validated correlation coefficients and limits of agreement (LOAs) of the Bland-Altman analysis of the calculated values for FFM m HH and FFM DXA were 0.958 and -4.369-4.343 kg, respectively, for hand-to-foot BIA model measurements for men; the FFM (FFM m HF ) and FFM DXA were 0.958 and -4.356-4.375 kg, respectively. The hand-to-hand BIA model estimating equation for female participants was FFM F HH = 0.615 h²/Z HH - 0.144 year + 0.132 weight + 16.507 ( r ² = 0.870, SEE = 1.884 kg, n = 201); the three mean validated correlation coefficient and LOA for the hand-to-foot BIA model measurements for female participants (FFM F HH and FFM DXA ) were 0.929 and -3.880-3.886 kg, respectively. The FFM HF and FFM DXA were 0.942 and -3.511-3.489 kg, respectively. The results of both hand-to-hand and hand-to-foot BIA models demonstrated similar reliability, and the hand-to-hand BIA models are practical for assessing FFM.

Influence of Posture and Frequency Modes in Total Body Water Estimation Using Bioelectrical Impedance Spectroscopy in Boys and Adult Males

Directory of Open Access Journals (Sweden)

Masaharu Kagawa

2014-05-01

Full Text Available The aim of the study was to examine differences in total body water (TBW measured using single-frequency (SF and multi-frequency (MF modes of bioelectrical impedance spectroscopy (BIS in children and adults measured in different postures using the deuterium (2H dilution technique as the reference. Twenty-three boys and 26 adult males underwent assessment of TBW using the dilution technique and BIS measured in supine and standing positions using two frequencies of the SF mode (50 kHz and 100 kHz and the MF mode. While TBW estimated from the MF mode was comparable, extra-cellular fluid (ECF and intra-cellular fluid (ICF values differed significantly (p < 0.01 between the different postures in both groups. In addition, while estimated TBW in adult males using the MF mode was significantly (p < 0.01 greater than the result from the dilution technique, TBW estimated using the SF mode and prediction equation was significantly (p < 0.01 lower in boys. Measurement posture may not affect estimation of TBW in boys and adult males, however, body fluid shifts may still occur. In addition, technical factors, including selection of prediction equation, may be important when TBW is estimated from measured impedance.

Hand Shape Affects Access to Memories

NARCIS (Netherlands)

K. Dijkstra (Katinka); M.P. Kaschak; R.A. Zwaan (Rolf)

2008-01-01

textabstractThe present study examined the ways that body posture facilitated retrieval of autobiographical memories in more detail by focusing on two aspects of congruence in position of a specific body part: hand shape and hand orientation. Hand shape is important in the tactile perception and

Postural And Eye-Positional Effects On Human Biting Force: An Experimental Study

Directory of Open Access Journals (Sweden)

Altay Tabancacı

2012-06-01

Full Text Available Muscle groups affected on biting force are called temporal muscle as a major and masseter muscle as a minor. According to the human posture stability, forces of these muscles vary with the force directions. In this case, experimental investigation is strictly important such that biting force under different postural and eye- positional situations is changed. In this study, seven-male and seven-female within the age-range of 17-24 are considered corresponding to having with restorated molar tooth and without that type of tooth. With the help of specially designed biting fork, different posture- and eye-positions are investigated for experimental biting force analysis. Changes in eye-positions are not indicated significant difference for all postural positions. On one hand, it is obtained that biting force of no-filling tooth in men becomes maximum if facial muscles give full effort to biting. On the other hand, effect of facial muscles for women is not clearly noticed depending on the postural differences.

The left IPL represents stored hand-postures for object use and action prediction

Directory of Open Access Journals (Sweden)

Michiel evan Elk

2014-04-01

Full Text Available Action semantics enables us to plan actions with objects and to predict others’ object-directed actions as well. Previous studies have suggested that action semantics are represented in a fronto-parietal action network that has also been implicated to play a role in action observation. In the present fMRI study it was investigated how activity within this network changes as a function of the predictability of an action involving multiple objects and requiring the use of action semantics. Participants performed an action prediction task in which they were required to anticipate the use of a centrally presented object that could be moved to an associated target object (e.g. hammer - nail. The availability of actor information (i.e. presenting a hand grasping the central object and the number of possible target objects (i.e. 0, 1 or 2 target objects were independently manipulated, resulting in different levels of predictability. It was found that making an action prediction based on actor information resulted in an increased activation in the extrastriate body area (EBA and the fronto-parietal action observation network (AON. Predicting actions involving a target object resulted in increased activation in the bilateral IPL and frontal motor areas. Within the AON, activity in the left inferior parietal lobe (IPL and the left premotor cortex (PMC increased as a function of the level of action predictability. Together these findings suggest that the left IPL represents stored hand-postures that can be used for planning object-directed actions and for predicting other’s actions as well.

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.

Hand surface area estimation formula using 3D anthropometry.

Science.gov (United States)

Hsu, Yao-Wen; Yu, Chi-Yuang

2010-11-01

Hand surface area is an important reference in occupational hygiene and many other applications. This study derives a formula for the palm surface area (PSA) and hand surface area (HSA) based on three-dimensional (3D) scan data. Two-hundred and seventy subjects, 135 males and 135 females, were recruited for this study. The hand was measured using a high-resolution 3D hand scanner. Precision and accuracy of the scanner is within 0.67%. Both the PSA and HSA were computed using the triangular mesh summation method. A comparison between this study and previous textbook values (such as in the U.K. teaching text and Lund and Browder chart discussed in the article) was performed first to show that previous textbooks overestimated the PSA by 12.0% and HSA by 8.7% (for the male, PSA 8.5% and HSA 4.7%, and for the female, PSA 16.2% and HSA 13.4%). Six 1D measurements were then extracted semiautomatically for use as candidate estimators for the PSA and HSA estimation formula. Stepwise regressions on these six 1D measurements and variable dependency test were performed. Results show that a pair of measurements (hand length and hand breadth) were able to account for 96% of the HSA variance and up to 98% of the PSA variance. A test of the gender-specific formula indicated that gender is not a significant factor in either the PSA or HSA estimation.

Estimating volume, biomass, and potential emissions of hand-piled fuels

Science.gov (United States)

Clinton S. Wright; Cameron S. Balog; Jeffrey W. Kelly

2009-01-01

Dimensions, volume, and biomass were measured for 121 hand-constructed piles composed primarily of coniferous (n = 63) and shrub/hardwood (n = 58) material at sites in Washington and California. Equations using pile dimensions, shape, and type allow users to accurately estimate the biomass of hand piles. Equations for estimating true pile volume from simple geometric...

Comparative study of state-of-the-art myoelectric controllers for multigrasp prosthetic hands.

Science.gov (United States)

Segil, Jacob L; Controzzi, Marco; Weir, Richard F ff; Cipriani, Christian

2014-01-01

A myoelectric controller should provide an intuitive and effective human-machine interface that deciphers user intent in real-time and is robust enough to operate in daily life. Many myoelectric control architectures have been developed, including pattern recognition systems, finite state machines, and more recently, postural control schemes. Here, we present a comparative study of two types of finite state machines and a postural control scheme using both virtual and physical assessment procedures with seven nondisabled subjects. The Southampton Hand Assessment Procedure (SHAP) was used in order to compare the effectiveness of the controllers during activities of daily living using a multigrasp artificial hand. Also, a virtual hand posture matching task was used to compare the controllers when reproducing six target postures. The performance when using the postural control scheme was significantly better (p state machines during the physical assessment when comparing within-subject averages using the SHAP percent difference metric. The virtual assessment results described significantly greater completion rates (97% and 99%) for the finite state machines, but the movement time tended to be faster (2.7 s) for the postural control scheme. Our results substantiate that postural control schemes rival other state-of-the-art myoelectric controllers.

An Efficient Solution for Hand Gesture Recognition from Video Sequence

Directory of Open Access Journals (Sweden)

PRODAN, R.-C.

2012-08-01

Full Text Available The paper describes a system of hand gesture recognition by image processing for human robot interaction. The recognition and interpretation of the hand postures acquired through a video camera allow the control of the robotic arm activity: motion - translation and rotation in 3D - and tightening/releasing the clamp. A gesture dictionary was defined and heuristic algorithms for recognition were developed and tested. The system can be used for academic and industrial purposes, especially for those activities where the movements of the robotic arm were not previously scheduled, for training the robot easier than using a remote control. Besides the gesture dictionary, the novelty of the paper consists in a new technique for detecting the relative positions of the fingers in order to recognize the various hand postures, and in the achievement of a robust system for controlling robots by postures of the hands.

Musculoskeletal pain and posture decrease step length in young adults

Directory of Open Access Journals (Sweden)

Maria Regina Rachmawati

2009-08-01

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

Musculoskeletal pain and posture decrease step length in young adults

Directory of Open Access Journals (Sweden)

Maria Regina Rachmawati

2016-02-01

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

The influence of cooling forearm/hand and gender on estimation of handgrip strength.

Science.gov (United States)

Cheng, Chih-Chan; Shih, Yuh-Chuan; Tsai, Yue-Jin; Chi, Chia-Fen

2014-01-01

Handgrip strength is essential in manual operations and activities of daily life, but the influence of forearm/hand skin temperature on estimation of handgrip strength is not well documented. Therefore, the present study intended to investigate the effect of local cooling of the forearm/hand on estimation of handgrip strength at various target force levels (TFLs, in percentage of MVC) for both genders. A cold pressor test was used to lower and maintain the hand skin temperature at 14°C for comparison with the uncooled condition. A total of 10 male and 10 female participants were recruited. The results indicated that females had greater absolute estimation deviations. In addition, both genders had greater absolute deviations in the middle range of TFLs. Cooling caused an underestimation of grip strength. Furthermore, a power function is recommended for establishing the relationship between actual and estimated handgrip force. Statement of relevance: Manipulation with grip strength is essential in daily life and the workplace, so it is important to understand the influence of lowering the forearm/hand skin temperature on grip-strength estimation. Females and the middle range of TFL had greater deviations. Cooling the forearm/hand tended to cause underestimation, and a power function is recommended for establishing the relationship between actual and estimated handgrip force. Practitioner Summary: It is important to understand the effect of lowering the forearm/hand skin temperature on grip-strength estimation. A cold pressor was used to cool the hand. The cooling caused underestimation, and a power function is recommended for establishing the relationship between actual and estimated handgrip force. Manipulation with grip strength is essential in daily life and the workplace, so it is important to understand the influence of lowering the forearm/hand skin temperature on grip-strength estimation. Females and the middle range of TFL had greater deviations. Cooling the

Postura da mão e imagética motora: um estudo sobre reconhecimento de partes do corpo Hand posture and motor imagery: a body-part recognition study

Directory of Open Access Journals (Sweden)

AP Lameira

2008-10-01

Full Text Available OBJETIVOS: Assim como a imagética motora, o reconhecimento de partes do corpo aciona representações somatosensoriais específicas. Essas representações são ativadas implicitamente para comparar o corpo com o estímulo. No presente estudo, investigou-se a influência da informação proprioceptiva da postura no reconhecimento de partes do corpo (mãos e propõe-se a utilização dessa tarefa na reabilitação de pacientes neurológicos. MATERIAIS E MÉTODOS: Dez voluntários destros participaram do experimento. A tarefa era reconhecer a lateralidade de figuras da mão apresentada, em várias perspectivas e em vários ângulos de orientação. Para a figura da mão direita, o voluntário pressionava a tecla direita e para a figura da mão esquerda, a tecla esquerda. Os voluntários realizavam duas sessões: uma com as mãos na postura prona e outra com as mãos na postura supina. RESULTADOS: Os tempos de reação manual (TRM eram maiores para as vistas e orientações, nas quais é difícil realizar o movimento real, mostrando que durante a tarefa, existe um acionamento de representações motoras para comparar o corpo com o estímulo. Além disso, existe uma influência da postura do sujeito em vistas e ângulos específicos. CONCLUSÕES: Estes resultados mostram que representações motoras são ativadas para comparar o corpo com o estímulo e que a postura da mão influencia esta ressonância entre estímulo e parte do corpo.OBJECTIVE: Recognition of body parts activates specific somatosensory representations in a way that is similar to motor imagery. These representations are implicitly activated to compare the body with the stimulus. In the present study, we investigate the influence of proprioceptive information relating to body posture on the recognition of body parts (hands. It proposes that this task could be used for rehabilitation of neurological patients. METHODS: Ten right-handed volunteers participated in this experiment. The

Contingency learning deficits and generalization in chronic unilateral hand pain patients.

Science.gov (United States)

Meulders, Ann; Harvie, Daniel S; Bowering, Jane K; Caragianis, Suzanne; Vlaeyen, Johan W S; Moseley, G Lorimer

2014-10-01

Contingency learning, in particular the formation of danger beliefs, underpins conditioned fear and avoidance behavior, yet equally important is the formation of safety beliefs. That is, when threat beliefs and accompanying fear/avoidance spread to technically safe cues, it might cause disability. Indeed, such over generalization has been advanced as a trans-diagnostic pathologic marker, but it has not been investigated in chronic pain. Using a novel hand pain scenario contingency learning task, we tested the hypotheses that chronic hand pain patients demonstrate less differential pain expectancy judgments because of poor safety learning and demonstrate broader generalization gradients than healthy controls. Participants viewed digitized 3-dimensional hands in different postures presented in random order (conditioned stimulus [CS]) and rated the likelihood that a fictive patient would feel pain when moving the hand into that posture. Subsequently, the outcome (pain/no pain) was presented on the screen. One hand posture was followed by pain (CS+), another was not (CS-). Generalization was tested using novel hand postures (generalization stimuli) that varied in how similar they were to the original conditioned stimuli. Patients, but not healthy controls, demonstrated a contingency learning deficit determined by impaired safety learning, but not by exaggerated pain expectancy toward the CS+. Patients showed flatter, asymmetric generalization gradients than the healthy controls did, with higher pain expectancy for novel postures that were more similar to the original CS-. The results clearly uphold our hypotheses and suggest that contingency learning deficits might be important in the development and maintenance of the chronic pain-related disability. Chronic hand pain patients demonstrate 1) reduced differential contingency learning determined by a lack of safety belief formation, but not by exaggerated threat belief formation, and 2) flatter, asymmetric

Mobile Phone Use Behaviors and Postures on Public Transportation Systems.

Science.gov (United States)

Liang, Huey-Wen; Hwang, Yaw-Huei

2016-01-01

Mobile phones are common in our daily life, but the users' preferences for postures or screen operating styles have not been studied. This was a cross-sectional and observational study. We randomly sampled passengers who used mobile phones on the Mass Rapid Transit (MRT) system in metropolitan Taipei. A checklist was used to observe their body postures and screen operating styles while sitting or standing. As a result, 1,230 subjects from 400 trips were observed. Overall, of all the passengers who were sitting, 41% of them were using mobile phones. The majority of the tasks involved browsing (84%) with their phones in a portrait orientation (93%). Different-hand holding/operating was the most commonly used operating style while sitting (46%) and same-hand holding/operating was the most common while standing (46%). The distribution of screen operating styles was significantly different for those sitting than for those standing and for different genders and age groups. The most frequently observed postures while sitting were having one's trunk against a backrest, feet on the floor and with or without an arm supported (58%). As for the users who were standing, the both- and different-hands groups had a high proportion of arms unsupported, feet on the floor and either their trunk supported or not. In contrast, the same-hand group tended to have their trunk unsupported, were holding a pole or handstrap and had both feet on floor. Further studies are warranted to characterize the ergonomic exposure of these commonly used postures and operating styles, and our results will help guide the selection of experimental conditions for laboratory settings.

Effects of external loads on postural sway during quiet stance in adults aged 20-80 years.

Science.gov (United States)

Hill, M W; Duncan, M J; Oxford, S W; Kay, A D; Price, M J

2018-01-01

The purpose of this study was to investigate the effects of holding external loads on postural sway during upright stance across age decades. Sixty-five healthy adults (females, n = 35), aged 18-80 years were assessed in four conditions; (1) standing without holding a load, holding a load corresponding to 5% body mass in the (2) left hand, (3) right hand and (4) both hands. The centre of pressure (COP) path length and anteroposterior and mediolateral COP displacement were used to indirectly assess postural sway. External loading elicited reductions in COP measures of postural sway in older age groups only (P  0.05). Holding external loads during standing is relevant to many activities of daily living (i.e. holding groceries). The reduction in postural sway may suggest this type of loading has a stabilising effect during quiet standing among older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimation of hand index for male industrial workers of Haryana State

African Journals Online (AJOL)

Hand index derived from measured hand dimensions can be used to estimate differences related to sex, age and race in forensic and legal sciences. It has been calculated as percentage of hand breadth over the hand length; which suggests that the male industrial workers population of state belong to mesocheir group of ...

Political Market Orientation and Strategic Party Postures in Danish Political Parties

DEFF Research Database (Denmark)

Ormrod, Robert P.; Henneberg, Stephan

2011-01-01

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

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.

The Posture of Putting One's Palms Together Modulates Visual Motion Event Perception.

Science.gov (United States)

Saito, Godai; Gyoba, Jiro

2018-02-01

We investigated the effect of an observer's hand postures on visual motion perception using the stream/bounce display. When two identical visual objects move across collinear horizontal trajectories toward each other in a two-dimensional display, observers perceive them as either streaming or bouncing. In our previous study, we found that when observers put their palms together just below the coincidence point of the two objects, the percentage of bouncing responses increased, mainly depending on the proprioceptive information from their own hands. However, it remains unclear if the tactile or haptic (force) information produced by the postures mostly influences the stream/bounce perception. We solved this problem by changing the tactile and haptic information on the palms of the hands. Experiment 1 showed that the promotion of bouncing perception was observed only when the posture of directly putting one's palms together was used, while there was no effect when a brick was sandwiched between the participant's palms. Experiment 2 demonstrated that the strength of force used when putting the palms together had no effect on increasing bounce perception. Our findings indicate that the hands-induced bounce effect derives from the tactile information produced by the direct contact between both palms.

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

Science.gov (United States)

Yaguchi, Chie; Fujiwara, Katsuo; Kiyota, Naoe

2017-12-22

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

QC operator’s nonneutral posture against musculoskeletal disorder’s (MSDs) risks

Science.gov (United States)

Kautsar, F.; Gustopo, D.; Achmadi, F.

2018-04-01

Musculoskeletal disorders refer to a gamut of inflammatory and degenerative disorders aggravated largely by the performance of work. It is the major cause of pain, disability, absenteeism and reduced productivity among workers worldwide. Although it is not fatal, MSDs have the potential to develop into serious injuries in the musculoskeletal system if ignored. QC operators work in nonneutral body posture. This cross-sectional study was condusted in order to investigate correlation between risk assessment results of QEC and body posture calculation of mannequin pro. Statistical analysis was condusted using SPSS version 16.0. Validity test, Reliability test and Regression analysis were conducted to compare the risk assessment output of applied method and nonneutral body posture simulation. All of QEC’s indicator classified as valid and reliable. The result of simple regression anlysis are back (0.3264.32), wrist/hand (4.86 >4.32) and neck (1.298 <4.32). Result of this study shows that there is an influence between nonneutral body posture of the QC operator during work with risk of musculoskeletal disorders. The potential risk of musculoskeletal disorders is in the shoulder/arm and wrist/hand of the QC operator, whereas the back and neck are not affected.

Human Hand Motion Analysis and Synthesis of Optimal Power Grasps for a Robotic Hand

Directory of Open Access Journals (Sweden)

Francesca Cordella

2014-03-01

Full Text Available Biologically inspired robotic systems can find important applications in biomedical robotics, since studying and replicating human behaviour can provide new insights into motor recovery, functional substitution and human-robot interaction. The analysis of human hand motion is essential for collecting information about human hand movements useful for generalizing reaching and grasping actions on a robotic system. This paper focuses on the definition and extraction of quantitative indicators for describing optimal hand grasping postures and replicating them on an anthropomorphic robotic hand. A motion analysis has been carried out on six healthy human subjects performing a transverse volar grasp. The extracted indicators point to invariant grasping behaviours between the involved subjects, thus providing some constraints for identifying the optimal grasping configuration. Hence, an optimization algorithm based on the Nelder-Mead simplex method has been developed for determining the optimal grasp configuration of a robotic hand, grounded on the aforementioned constraints. It is characterized by a reduced computational cost. The grasp stability has been tested by introducing a quality index that satisfies the form-closure property. The grasping strategy has been validated by means of simulation tests and experimental trials on an arm-hand robotic system. The obtained results have shown the effectiveness of the extracted indicators to reduce the non-linear optimization problem complexity and lead to the synthesis of a grasping posture able to replicate the human behaviour while ensuring grasp stability. The experimental results have also highlighted the limitations of the adopted robotic platform (mainly due to the mechanical structure to achieve the optimal grasp configuration.

Body schema and corporeal self-recognition in the alien hand syndrome.

Science.gov (United States)

Olgiati, Elena; Maravita, Angelo; Spandri, Viviana; Casati, Roberta; Ferraro, Francesco; Tedesco, Lucia; Agostoni, Elio Clemente; Bolognini, Nadia

2017-07-01

The alien hand syndrome (AHS) is a rare neuropsychological disorder characterized by involuntary, yet purposeful, hand movements. Patients with the AHS typically complain about a loss of agency associated with a feeling of estrangement for actions performed by the affected limb. The present study explores the integrity of the body representation in AHS, focusing on 2 main processes: multisensory integration and visual self-recognition of body parts. Three patients affected by AHS following a right-hemisphere stroke, with clinical symptoms akin to the posterior variant of AHS, were tested and their performance was compared with that of 18 age-matched healthy controls. AHS patients and controls underwent 2 experimental tasks: a same-different visual matching task for body postures, which assessed the ability of using your own body schema for encoding others' body postural changes (Experiment 1), and an explicit self-hand recognition task, which assessed the ability to visually recognize your own hands (Experiment 2). As compared to controls, all AHS patients were unable to access a reliable multisensory representation of their alien hand and use it for decoding others' postural changes; however, they could rely on an efficient multisensory representation of their intact (ipsilesional) hand. Two AHS patients also presented with a specific impairment in the visual self-recognition of their alien hand, but normal recognition of their intact hand. This evidence suggests that the AHS following a right-hemisphere stroke may involve a disruption of the multisensory representation of the alien limb; instead, self-hand recognition mechanisms may be spared. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Multiplication factor versus regression analysis in stature estimation from hand and foot dimensions.

Science.gov (United States)

Krishan, Kewal; Kanchan, Tanuj; Sharma, Abhilasha

2012-05-01

Estimation of stature is an important parameter in identification of human remains in forensic examinations. The present study is aimed to compare the reliability and accuracy of stature estimation and to demonstrate the variability in estimated stature and actual stature using multiplication factor and regression analysis methods. The study is based on a sample of 246 subjects (123 males and 123 females) from North India aged between 17 and 20 years. Four anthropometric measurements; hand length, hand breadth, foot length and foot breadth taken on the left side in each subject were included in the study. Stature was measured using standard anthropometric techniques. Multiplication factors were calculated and linear regression models were derived for estimation of stature from hand and foot dimensions. Derived multiplication factors and regression formula were applied to the hand and foot measurements in the study sample. The estimated stature from the multiplication factors and regression analysis was compared with the actual stature to find the error in estimated stature. The results indicate that the range of error in estimation of stature from regression analysis method is less than that of multiplication factor method thus, confirming that the regression analysis method is better than multiplication factor analysis in stature estimation. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

NUI framework based on real-time head pose estimation and hand gesture recognition

Directory of Open Access Journals (Sweden)

Kim Hyunduk

2016-01-01

Full Text Available The natural user interface (NUI is used for the natural motion interface without using device or tool such as mice, keyboards, pens and markers. In this paper, we develop natural user interface framework based on two recognition module. First module is real-time head pose estimation module using random forests and second module is hand gesture recognition module, named Hand gesture Key Emulation Toolkit (HandGKET. Using the head pose estimation module, we can know where the user is looking and what the user’s focus of attention is. Moreover, using the hand gesture recognition module, we can also control the computer using the user’s hand gesture without mouse and keyboard. In proposed framework, the user’s head direction and hand gesture are mapped into mouse and keyboard event, respectively.

Acute Effects of Hand Elevation and Wrist Position on Mean Arterial Pressure and Pulse Rate Measured in the Hand

National Research Council Canada - National Science Library

Shibley, Lee

2000-01-01

Musculoskeletal disorders (MSD) to the wrist and hand are common among workers, and are associated with working conditions that use forceful, repetitive and extreme wrist joint postures that including end range flexion...

Detection of motion and posture change using an IR-UWB radar.

Science.gov (United States)

Van Nguyen; Javaid, Abdul Q; Weitnauer, Mary A

2016-08-01

Impulse radio ultra-wide band (IR-UWB) radar has recently emerged as a promising candidate for non-contact monitoring of respiration and heart rate. Different studies have reported various radar based algorithms for estimation of these physiological parameters. The radar can be placed under a subject's mattress as he lays stationary on his back or it can be attached to the ceiling directly above the subject's bed. However, advertent or inadvertent movement on part of the subject and different postures can affect the radar returned signal and also the accuracy of the estimated parameters from it. The detection and analysis of these postural changes can not only lead to improvement in estimation algorithms but also towards prevention of bed sores and ulcers in patients who require periodic posture changes. In this paper, we present an algorithm that detects and quantifies different types of motion events using an under-the-mattress IR-UWB radar. The algorithm also indicates a change in posture after a macro-movement event. Based on the findings of this paper, we anticipate that IR-UWB radar can be used for extracting posture related information in non-clinical enviroments for patients who are bed-ridden.

Registration-based segmentation with articulated model from multipostural magnetic resonance images for hand bone motion animation.

Science.gov (United States)

Chen, Hsin-Chen; Jou, I-Ming; Wang, Chien-Kuo; Su, Fong-Chin; Sun, Yung-Nien

2010-06-01

The quantitative measurements of hand bones, including volume, surface, orientation, and position are essential in investigating hand kinematics. Moreover, within the measurement stage, bone segmentation is the most important step due to its certain influences on measuring accuracy. Since hand bones are small and tubular in shape, magnetic resonance (MR) imaging is prone to artifacts such as nonuniform intensity and fuzzy boundaries. Thus, greater detail is required for improving segmentation accuracy. The authors then propose using a novel registration-based method on an articulated hand model to segment hand bones from multipostural MR images. The proposed method consists of the model construction and registration-based segmentation stages. Given a reference postural image, the first stage requires construction of a drivable reference model characterized by hand bone shapes, intensity patterns, and articulated joint mechanism. By applying the reference model to the second stage, the authors initially design a model-based registration pursuant to intensity distribution similarity, MR bone intensity properties, and constraints of model geometry to align the reference model to target bone regions of the given postural image. The authors then refine the resulting surface to improve the superimposition between the registered reference model and target bone boundaries. For each subject, given a reference postural image, the proposed method can automatically segment all hand bones from all other postural images. Compared to the ground truth from two experts, the resulting surface image had an average margin of error within 1 mm (mm) only. In addition, the proposed method showed good agreement on the overlap of bone segmentations by dice similarity coefficient and also demonstrated better segmentation results than conventional methods. The proposed registration-based segmentation method can successfully overcome drawbacks caused by inherent artifacts in MR images and

Modelflow Estimates of Stroke Volume Do Not Correlate With Doppler Ultrasound Estimates During Upright Posture

Science.gov (United States)

Ferguson, Connor R.; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.; Laurie, Steven S.

2014-01-01

less than US (-37+/-16 ml, pdifferent estimates between methods (FM: 95+/-17, US: 75+/-32, pfocus on identifying factors contributing to differences between these measurement techniques in order to make use of a simple method for assessing beat-by-beat changes in SV during postural changes, especially during field testing.

Estimation of stature from hand and foot dimensions in a Korean population.

Science.gov (United States)

Kim, Wonjoon; Kim, Yong Min; Yun, Myung Hwan

2018-04-01

The estimation of stature using foot and hand dimensions is essential in the process of personal identification. The shapes of feet and hands vary depending on races and gender, and it is of great importance to design an adequate equation in consideration of variances to estimate stature. This study is based on a total of 5,195 South Korean males and females, aged from 20 to 59 years. Body dimensions of stature, hand length, hand breadth, foot length, and foot breadth were measured according to standard anthropometric procedures. The independent t-test was performed in order to verify significant gender-induced differences and the results showed that there was significant difference between males and females for all the foot-hand dimensions (pfoot length showed highest correlation, whereas the hand breadth showed least correlation. The stepwise regression analysis was conducted, and the results showed that males had the highest prediction accuracy in the regression equation consisting of foot length and hand length (R 2 =0.532), whereas females had the highest accuracy in the regression model consisting of foot length and hand breadth (R 2 =0.437) The findings of this study indicated that hand and foot dimensions can be used to predict the stature of South Korean in the forensic science field. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

[Brief on the standardization of the practitioner's posture in acupuncture operation].

Science.gov (United States)

Lu, Yonghui

2015-07-01

To discuss the standardization of the practitioner's posture in acupuncture operation. Based on the relevant discussion on 'way to holding needle' recorded in Lingshu (Miraculous Pivot) and in association with the clinical acupuncture practice, it was required to standardize the practitioner's posture in acupuncture operation in reference to Lingshu (Miraculous Pivot). The standard standing posture of the practitioner is the precondition of acupuncture operation; the standard holding needle with the puncture hand is the key to the exercise of acupuncture technique and the regular standing orientation is the need of acupuncture operation. The three aspects are complemented each other, which is the coordinative procedure in acupuncture operation and enable the practitioner's high concentration with the body, qi and mind involved.

Carrying shopping bags does not alter static postural stability and gait parameters in healthy older females.

Science.gov (United States)

Bampouras, Theodoros M; Dewhurst, Susan

2016-05-01

Food shopping is an important aspect of maintaining independence and social interaction in older age. Carriage of shopping bags alters the body's weight distribution which, depending on load distribution, could potentially increase instability during standing and walking. The study examined the effect of carrying UK style shopping bags on static postural stability and gait in healthy older and young females. Nine older (71.0±6.0 years) and 10 young (26.7±5.2 years) females were assessed in five conditions carrying no bags, one 1.5kg bag in each hand, one 3kg bag in each hand, one 1.5kg bag in preferred hand, one 3kg bag in preferred hand. Antero-posterior and medio-lateral displacement, and 95% ellipse area from a 30s quiet standing were used for postural stability assessment. Stride length and its coefficient of variation, total double support time, step asymmetry and gait stability ratio were calculated from 1min treadmill walking at self-selected speed for gait assessment. Carrying shopping bags did not negatively affect postural stability or gait variables, in either group. Further, in older individuals, a decrease in sway velocity was found when holding bags during the postural stability assessment (pbags, irrespective of the load distribution, may have a stabilising effect during quiet standing. These results should help to alleviate concerns regarding safety of carrying shopping bags and help encourage shopping, both as a social and as a physical activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Bipedal tool use strengthens chimpanzee hand preferences

DEFF Research Database (Denmark)

Braccini, Stephanie; Lambeth, Susan; Schapiro, Steve

2010-01-01

The degree to which non-human primate behavior is lateralized, at either individual or population levels, remains controversial. We investigated the relationship between hand preference and posture during tool use in chimpanzees (Pan troglodytes) during bipedal tool use. We experimentally induced...

Unraveling the mechanisms underlying postural instability in Parkinson's disease using dynamic posturography.

Science.gov (United States)

Nonnekes, Jorik; de Kam, Digna; Geurts, Alexander C H; Weerdesteyn, Vivian; Bloem, Bastiaan R

2013-12-01

Postural instability, one of the cardinal symptoms of Parkinson's disease (PD), has devastating consequences for affected patients. Better strategies to prevent falls are needed, but this calls for an improved understanding of the complex mechanisms underlying postural instability. We must also improve our ability to timely identify patients at risk of falling. Dynamic posturography is a promising avenue to achieve these goals. The latest moveable platforms can deliver 'real-life' balance perturbations, permitting study of everyday fall circumstances. Dynamic posturography studies have shown that PD patients have fundamental problems in scaling their postural responses in accordance with the need of the actual balance task at hand. On-going studies evaluate the predictive ability of impaired posturography performance for daily life falls. We also review recent work aimed at exploring balance correcting steps in PD, and the presumed interaction between startle pathways and postural responses.

Visual Information and Support Surface for Postural Control in Visual Search Task.

Science.gov (United States)

Huang, Chia-Chun; Yang, Chih-Mei

2016-10-01

When standing on a reduced support surface, people increase their reliance on visual information to control posture. This assertion was tested in the current study. The effects of imposed motion and support surface on postural control during visual search were investigated. Twelve participants (aged 21 ± 1.8 years; six men and six women) stood on a reduced support surface (45% base of support). In a room that moved back and forth along the anteroposterior axis, participants performed visual search for a given letter in an article. Postural sway variability and head-room coupling were measured. The results of head-room coupling, but not postural sway, supported the assertion that people increase reliance on visual information when standing on a reduced support surface. Whether standing on a whole or reduced surface, people stabilized their posture to perform the visual search tasks. Compared to a fixed target, searching on a hand-held target showed greater head-room coupling when standing on a reduced surface. © The Author(s) 2016.

Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation

Directory of Open Access Journals (Sweden)

Giuseppe Airò Farulla

2016-02-01

Full Text Available Vision-based Pose Estimation (VPE represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master–slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator’s hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers’ hands movements.

Development of a biometric method to estimate age on hand radiographs.

Science.gov (United States)

Remy, Floriane; Hossu, Gabriela; Cendre, Romain; Micard, Emilien; Mainard-Simard, Laurence; Felblinger, Jacques; Martrille, Laurent; Lalys, Loïc

2017-02-01

Age estimation of living individuals aged less than 13, 18 or 21 years, which are some relevant legal ages in most European countries, is currently problematic in the forensic context. Thus, numerous methods are available for legal authorities, although their efficiency can be discussed. For those reasons, we aimed to propose a new method, based on the biometric analysis of hand bones. 451 hand radiographs of French individuals under the age of 21 were retrospectively analyzed. This total sample was divided into three subgroups bounded by the relevant legal ages previously mentioned: 0-13, 13-18 and 18-21 years. On these radiographs, we numerically applied the osteometric board method used in anthropology, by including each metacarpal and proximal phalange of the five hand rays in the smallest rectangle possible. In that we can access their length and width information thanks to a measurement protocol developed precisely for our treatment with the ORS Visual ® software. Then, a statistical analysis was performed from these biometric data: a Linear Discriminant Analysis (LDA) evaluated the probability for an individual to belong to one of the age group (0-13, 13-18 or 18-21); and several multivariate regression models were tested for the establishment of age estimation formulas for each of these age groups. The mean Correlation Coefficient between chronological age and both lengths and widths of hand bones is equal to 0.90 for the total sample. Repeatability and reproducibility were assessed. The LDA could more easily predict the belonging to the 0-13 age group. Age can be estimated with a mean standard error which never exceeds 1 year for the 95% confidence interval. Finally, compared to the literature, we can conclude that estimating an age from the biometric information of metacarpals and proximal phalanges is promising. Copyright © 2016. Published by Elsevier B.V.

Obesity impact on the attentional cost for controlling posture.

Directory of Open Access Journals (Sweden)

Jean-Baptiste Mignardot

2010-12-01

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

Obesity Impact on the Attentional Cost for Controlling Posture

Science.gov (United States)

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

2010-01-01

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

New evaluation index for the retainability of a swimmer's horizontal posture.

Directory of Open Access Journals (Sweden)

Yasunori Watanabe

Full Text Available This study aims to investigate the effect of changes in buoyancy when a swimmer respires in a horizontal posture. We attempted to evaluate the levelness of swimmers' streamline posture by simultaneously measuring the lung capacity and buoyancy under water. The buoyancy was measured based on the changes in the vertical loads of the upper and lower limbs on the subjects' streamline posture under water. The horizontal x-axis as lung ventilation and the vertical y-axis as buoyancy forms a linear equation y = ax + b. The relation between hand (upper-limb buoyancy and lung ventilation is defined as y = a1x + b1 and that between foot (lower-limb buoyancy and lung ventilation as y = a2x + b2. Horizontal levelness was calculated as a ratio by dividing a2 by a1 using the inclination (a values from these formulas for an underwater streamline posture. We defined this ratio as the breathing-balance (BB ratio. Although the performance levels in the present study did not show any difference in the absolute quantity of air that humans can inhale in a streamline posture, the BB ratio was higher in a statistically significant manner in junior swimmers competing at international levels compared with the other groups of subjects (P < 0.001. This statistical difference in horizontal levelness, despite the absence of a noticeable difference in the absolute quantity of inhaled air, may be attributable to the way in which each person inhales and exhales air. Top-level junior swimmers that exhibited a high BB ratio might have inhaled in a way that would counteract the sinking of the lower limbs, for example, through abdominal respiration. When exhaling, on the other hand, they might have let out air gradually to mitigate the acceleration force involved in submerging the lower limbs.

The differences in postural reactions between scoliosis and scoliotic posture

Directory of Open Access Journals (Sweden)

Jacek Wilczyński

2017-05-01

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

Human-inspired feedback synergies for environmental interaction with a dexterous robotic hand.

Science.gov (United States)

Kent, Benjamin A; Engeberg, Erik D

2014-11-07

Effortless control of the human hand is mediated by the physical and neural couplings inherent in the structure of the hand. This concept was explored for environmental interaction tasks with the human hand, and a novel human-inspired feedback synergy (HFS) controller was developed for a robotic hand which synchronized position and force feedback signals to mimic observed human hand motions. This was achieved by first recording the finger joint motion profiles of human test subjects, where it was observed that the subjects would extend their fingers to maintain a natural hand posture when interacting with different surfaces. The resulting human joint angle data were used as inspiration to develop the HFS controller for the anthropomorphic robotic hand, which incorporated finger abduction and force feedback in the control laws for finger extension. Experimental results showed that by projecting a broader view of the tasks at hand to each specific joint, the HFS controller produced hand motion profiles that closely mimic the observed human responses and allowed the robotic manipulator to interact with the surfaces while maintaining a natural hand posture. Additionally, the HFS controller enabled the robotic hand to autonomously traverse vertical step discontinuities without prior knowledge of the environment, visual feedback, or traditional trajectory planning techniques.

Human-inspired feedback synergies for environmental interaction with a dexterous robotic hand

International Nuclear Information System (INIS)

Kent, Benjamin A; Engeberg, Erik D

2014-01-01

Effortless control of the human hand is mediated by the physical and neural couplings inherent in the structure of the hand. This concept was explored for environmental interaction tasks with the human hand, and a novel human-inspired feedback synergy (HFS) controller was developed for a robotic hand which synchronized position and force feedback signals to mimic observed human hand motions. This was achieved by first recording the finger joint motion profiles of human test subjects, where it was observed that the subjects would extend their fingers to maintain a natural hand posture when interacting with different surfaces. The resulting human joint angle data were used as inspiration to develop the HFS controller for the anthropomorphic robotic hand, which incorporated finger abduction and force feedback in the control laws for finger extension. Experimental results showed that by projecting a broader view of the tasks at hand to each specific joint, the HFS controller produced hand motion profiles that closely mimic the observed human responses and allowed the robotic manipulator to interact with the surfaces while maintaining a natural hand posture. Additionally, the HFS controller enabled the robotic hand to autonomously traverse vertical step discontinuities without prior knowledge of the environment, visual feedback, or traditional trajectory planning techniques. (paper)

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

Science.gov (United States)

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

2009-11-01

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

Effects of Hand Proximity and Movement Direction in Spatial and Temporal Gap Discrimination.

Science.gov (United States)

Wiemers, Michael; Fischer, Martin H

2016-01-01

Previous research on the interplay between static manual postures and visual attention revealed enhanced visual selection near the hands (near-hand effect). During active movements there is also superior visual performance when moving toward compared to away from the stimulus (direction effect). The "modulated visual pathways" hypothesis argues that differential involvement of magno- and parvocellular visual processing streams causes the near-hand effect. The key finding supporting this hypothesis is an increase in temporal and a reduction in spatial processing in near-hand space (Gozli et al., 2012). Since this hypothesis has, so far, only been tested with static hand postures, we provide a conceptual replication of Gozli et al.'s (2012) result with moving hands, thus also probing the generality of the direction effect. Participants performed temporal or spatial gap discriminations while their right hand was moving below the display. In contrast to Gozli et al. (2012), temporal gap discrimination was superior at intermediate and not near hand proximity. In spatial gap discrimination, a direction effect without hand proximity effect suggests that pragmatic attentional maps overshadowed temporal/spatial processing biases for far/near-hand space.

Posture Detection Based on Smart Cushion for Wheelchair Users

Directory of Open Access Journals (Sweden)

Congcong Ma

2017-03-01

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

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.

Hand Pose Estimation by Fusion of Inertial and Magnetic Sensing Aided by a Permanent Magnet.

Science.gov (United States)

Kortier, Henk G; Antonsson, Jacob; Schepers, H Martin; Gustafsson, Fredrik; Veltink, Peter H

2015-09-01

Tracking human body motions using inertial sensors has become a well-accepted method in ambulatory applications since the subject is not confined to a lab-bounded volume. However, a major drawback is the inability to estimate relative body positions over time because inertial sensor information only allows position tracking through strapdown integration, but does not provide any information about relative positions. In addition, strapdown integration inherently results in drift of the estimated position over time. We propose a novel method in which a permanent magnet combined with 3-D magnetometers and 3-D inertial sensors are used to estimate the global trunk orientation and relative pose of the hand with respect to the trunk. An Extended Kalman Filter is presented to fuse estimates obtained from inertial sensors with magnetic updates such that the position and orientation between the human hand and trunk as well as the global trunk orientation can be estimated robustly. This has been demonstrated in multiple experiments in which various hand tasks were performed. The most complex task in which simultaneous movements of both trunk and hand were performed resulted in an average rms position difference with an optical reference system of 19.7±2.2 mm whereas the relative trunk-hand and global trunk orientation error was 2.3±0.9 and 8.6±8.7 deg respectively.

Wearable kinesthetic systems for capturing and classifying body posture and gesture.

Science.gov (United States)

Tognetti, Alessandro; Lorussi, Federico; Tesconi, Mario; Bartalesi, Raphael; Zupone, Giuseppe; De Rossi, Danilo

2005-01-01

Monitoring body kinematics has fundamental relevance in several biological and technical disciplines. In particular the possibility to know the posture exactly may furnish a main aid in rehabilitation topics. This paper deals with the design, the development and the realization of sensing garments, from the characterization of innovative comfortable and spreadable sensors to the methodologies employed to gather information on posture and movement. In the present work an upper limb kinesthetic garment (ULKG), which allows to reconstruct shoulder, elbow and wrist movements and a kinesthetic glove able to detect posture an gesture of the hand are presented. Sensors are directly integrated in Lycra fabrics by using conductive elastomer (CE) sensors. CE sensors show piezoresistive properties when a deformation is applied and they can be integrated onto fabric or other flexible substrate to be employed as strain sensors.

Localization and Recognition of Dynamic Hand Gestures Based on Hierarchy of Manifold Classifiers

Science.gov (United States)

Favorskaya, M.; Nosov, A.; Popov, A.

2015-05-01

Generally, the dynamic hand gestures are captured in continuous video sequences, and a gesture recognition system ought to extract the robust features automatically. This task involves the highly challenging spatio-temporal variations of dynamic hand gestures. The proposed method is based on two-level manifold classifiers including the trajectory classifiers in any time instants and the posture classifiers of sub-gestures in selected time instants. The trajectory classifiers contain skin detector, normalized skeleton representation of one or two hands, and motion history representing by motion vectors normalized through predetermined directions (8 and 16 in our case). Each dynamic gesture is separated into a set of sub-gestures in order to predict a trajectory and remove those samples of gestures, which do not satisfy to current trajectory. The posture classifiers involve the normalized skeleton representation of palm and fingers and relative finger positions using fingertips. The min-max criterion is used for trajectory recognition, and the decision tree technique was applied for posture recognition of sub-gestures. For experiments, a dataset "Multi-modal Gesture Recognition Challenge 2013: Dataset and Results" including 393 dynamic hand-gestures was chosen. The proposed method yielded 84-91% recognition accuracy, in average, for restricted set of dynamic gestures.

LOCALIZATION AND RECOGNITION OF DYNAMIC HAND GESTURES BASED ON HIERARCHY OF MANIFOLD CLASSIFIERS

Directory of Open Access Journals (Sweden)

M. Favorskaya

2015-05-01

Full Text Available Generally, the dynamic hand gestures are captured in continuous video sequences, and a gesture recognition system ought to extract the robust features automatically. This task involves the highly challenging spatio-temporal variations of dynamic hand gestures. The proposed method is based on two-level manifold classifiers including the trajectory classifiers in any time instants and the posture classifiers of sub-gestures in selected time instants. The trajectory classifiers contain skin detector, normalized skeleton representation of one or two hands, and motion history representing by motion vectors normalized through predetermined directions (8 and 16 in our case. Each dynamic gesture is separated into a set of sub-gestures in order to predict a trajectory and remove those samples of gestures, which do not satisfy to current trajectory. The posture classifiers involve the normalized skeleton representation of palm and fingers and relative finger positions using fingertips. The min-max criterion is used for trajectory recognition, and the decision tree technique was applied for posture recognition of sub-gestures. For experiments, a dataset “Multi-modal Gesture Recognition Challenge 2013: Dataset and Results” including 393 dynamic hand-gestures was chosen. The proposed method yielded 84–91% recognition accuracy, in average, for restricted set of dynamic gestures.

PERANCANGAN KURSI RODA DAN LAY OUT KAMAR MANDI UNTUK MEMPERBAIKI POSTUR KERJA PERAWAT PANTI WREDHA SEMARANG

Directory of Open Access Journals (Sweden)

Purnawan Adi W

2012-02-01

Panti Wredha Berthany is a treatment for people who have been elderly. In this house most of the patients dapt not bathe without assistance of others. Nurses who help them a bath about the pain in the back of the spine that often dideritanya. This is due to bad postures nurse. To find out how bad postures nurses, the nurses conducted the analysis with the postures OWAS (Ovako Working Posture Analysis System. Method OWAS built as a tool to identify body postures which may be responsible for muscle problems (Musculoskeletal disorders. This method is based on the simple and systematic classification of work postures. OWAS postures in the workplace are categorized into 3 main body segment of the body, hands and feet. Kegunaanya improve conditions for workers in the work, so that work performance can be improved. Based on the results of analysis using the method OWAS, note that when the postures nurses bathe patients classified in category postures quite dangerous and very dangerous. Therefore, action needs to be improvements in form design wheelchair and lay out a bathroom can make it easier to work when the nurse wash the patient. With this design, the frequency of transfer of patients that must be done by the nurses decreased and postures during patient more better. Keywords: lay out, planning, postures in the workplace, OWAS

Age-related changes in hand dominance and functional asymmetry in older adults.

Directory of Open Access Journals (Sweden)

Anna Sebastjan

Full Text Available The aim of the study was to investigate fine motor performance and ascertain age-related changes in laterality between the dominant and non-dominant hand. A representative sample of 635 adults (144 males and 491 females aged 50 years and over completed a test battery MLS (Motor Performance Series to assess a broad range of hand functions. Functional asymmetry was observed in all four motor tests (postural tremor, aiming, tapping, and inserting long pins. Significant differences between the dominant and non-dominant hand were obtained in both sexes across all age groups, except in the oldest female group (age >70 for the aiming (number of hits and errors and postural tremor (number of errors tasks. These differences in age-related changes may be attributed to hemispheric asymmetry, environmental factors, or use-dependent plasticity. Conflicting evidence in the literature warrants additional research to better explain age-related alterations of hand dominance and manual performance in old age.

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.

Hand VR Exergame for Occupational Health Care.

Science.gov (United States)

Ortiz, Saskia; Uribe-Quevedo, Alvaro; Kapralos, Bill

2016-01-01

The widespread use and ubiquity of mobile computing technologies such as smartphones, tablets, laptops and portable gaming consoles has led to an increase in musculoskeletal disorders due to overuse, bad posture, repetitive movements, fixed postures and physical de-conditioning caused by low muscular demands while using (and over-using) these devices. In this paper we present the development of a hand motion-based virtual reality-based exergame for occupational health purposes that allows the user to perform simple exercises using a cost-effective non-invasive motion capture device to help overcome and prevent some of the muskoloskeletal problems associated with the over-use of keyboards and mobile devices.

Take a stand on your decisions, or take a sit: posture does not affect risk preferences in an economic task

OpenAIRE

O’Brien, Megan K.; Ahmed, Alaa A.

2014-01-01

Physiological and emotional states can affect our decision-making processes, even when these states are seemingly insignificant to the decision at hand. We examined whether posture and postural threat affect decisions in a non-related economic domain. Healthy young adults made a series of choices between economic lotteries in various conditions, including changes in body posture (sitting vs. standing) and changes in elevation (ground level vs. atop a 0.8-meter-high platform). We compared thre...

Human Posture Identification Using a MIMO Array

Directory of Open Access Journals (Sweden)

Dai Sasakawa

2018-03-01

Full Text Available The elderly are constantly in danger of falling and injuring themselves without anyone realizing it. A safety-monitoring system based on microwaves can ease these concerns. The authors have proposed safety-monitoring systems that use multiple-input multiple-output (MIMO radar to localize persons by capturing their biological activities such as respiration. However, our studies to date have focused on localization, which is easier to achieve than an estimation of human postures. This paper proposes a human posture identification scheme based on height and a Doppler radar cross section (RCS as estimated by a MIMO array. This scheme allows smart home applications to dispense with contact and wearable devices. Experiments demonstrate that this method can identify the supine position (i.e., after a fall with 100% accuracy, and the average identification rate is 95.0%.

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

Science.gov (United States)

Grasso, R; Zago, M; Lacquaniti, F

2000-01-01

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

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

Science.gov (United States)

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

2011-07-01

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

The influence of aging and attentional demands on recovery from postural instability.

Science.gov (United States)

Stelmach, G E; Zelaznik, H N; Lowe, D

1990-06-01

It is well known that the risk of a debilitating injury from a fall is much higher for elderly than for young individuals. In addition, it is well documented that healthy elderly subjects exhibit increased postural sway during normal stance tasks. In the present experiment, we explored the notion that control of minor postural instability in elderly subjects is attention demanding. Postural sway of eight elderly (mean age = 70.0 years) and eight young (mean age = 20.0 years) subjects was measured under two different secondary demands during stable and mildly unstable upright stance. There were two types of work loads. Either a cognitive (math task) or motor (hand-squeeze) task was performed during the second segment of a 50-second standing trial. The effect of these work loads on mean velocity, range, and variability of range of center of foot pressure was measured during the destabilizing activity of arm swinging and subsequent recovery period. Following seven seconds of 1 Hz arm-swinging activity, elderly subjects showed a marked increase in recovery time to normal stance when concurrently performing an arithmetic task. This result suggests that recovery from a posturally destabilizing activity, involving proprioceptive and vestibular information, places increased attentional demands on the postural support system of the elderly.

The impact of ergonomics intervention on trunk posture and cumulative compression load among carpet weavers.

Science.gov (United States)

Afshari, Davood; Motamedzade, Majid; Salehi, Reza; Soltanian, Alir Raze

2015-01-01

Work-related musculoskeletal disorders of back among weavers are prevalent. Epidemiological studies have shown an association between poor working postures and back disorders among carpet weavers. Therefore, the present study aimed to evaluate the impact of the traditional (A) and ergonomically designed (B) workstations on trunk posture and cumulative compression load in carpet weavers. In this study, subtasks were identified in terms of stressful postures and carpet weaving process. Postural data were collected during knotting and compacting subtasks using inclinometer during four hours for each workstation. Postural data, weight and height of the weavers were entered into the University of Michigan three-dimensional static biomechanical model for estimation of the compression load and cumulative load were estimated from the resultant load and exposure time. Thirteen healthy carpet weavers (four males and nine females) participated in the study. Median trunk flexion angle was reduced with workstation B during knotting subtask (18° versus 8.5°, pergonomically designed workstation.

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

Science.gov (United States)

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

2018-02-01

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

Dynamic postural stability in blind athletes using the biodex stability system.

Science.gov (United States)

Aydoğ, E; Aydoğ, S T; Cakci, A; Doral, M N

2006-05-01

Three systems affect the upright standing posture in humans - visual, vestibular, and somatosensory. It is well known that the visually impaired individuals have bad postural balance. On the other hand, it is a well documented fact that some sports can improve postural balance. Therefore, it is aimed in this study to evaluate the dynamic postural stability in goal-ball athletes. Twenty blind goal-ball players, 20 sighted and 20 sedentary blind controls were evaluated using the Biodex Stability System. Three adaptation trials and three test evaluations (a 20-second balance test at a platform stability of 8) were applied to the blind people, and to the sighted with eyes open and closed. Dynamic postural stability was measured on the basis of three indices: overall, anteroposterior, and mediolateral. Means of each test score were calculated. The tests results were compared for the blind athletes, sighted (with eyes open and closed) subjects, and sedentary blind people. There were significant differences between the results of the blind people and the sighted subjects with regards to all of the three indices. Although the stability of goal-ball players was better than sedentary blinds', only ML index values were statistically different (4.47 +/- 1.24 in the goal-ball players; 6.46 +/- 3.42 in the sedentary blind, p = 0.04). Dynamic postural stability was demonstrated to be affected by vision; and it was found that blind people playing goal-ball 1 - 2 days per week have higher ML stability than the sedentary sighted people.

Take a stand on your decisions, or take a sit: posture does not affect risk preferences in an economic task.

Science.gov (United States)

O'Brien, Megan K; Ahmed, Alaa A

2014-01-01

Physiological and emotional states can affect our decision-making processes, even when these states are seemingly insignificant to the decision at hand. We examined whether posture and postural threat affect decisions in a non-related economic domain. Healthy young adults made a series of choices between economic lotteries in various conditions, including changes in body posture (sitting vs. standing) and changes in elevation (ground level vs. atop a 0.8-meter-high platform). We compared three metrics between conditions to assess changes in risk-sensitivity: frequency of risky choices, and parameter fits of both utility and probability weighting parameters using cumulative prospect theory. We also measured skin conductance level to evaluate physiological response to the postural threat. Our results demonstrate that body posture does not significantly affect decision making. Secondly, despite increased skin conductance level, economic risk-sensitivity was unaffected by increased threat. Our findings indicate that economic choices are fairly robust to the physiological and emotional changes that result from posture or postural threat.

Arm-trunk coordination in wheelchair initiation displacement: A study of anticipatory and compensatory postural adjustments during different speeds and directions of propulsion.

Science.gov (United States)

Chikh, Soufien; Garnier, Cyril; Faupin, Arnaud; Pinti, Antonio; Boudet, Samuel; Azaiez, Fairouz; Watelain, Eric

2018-03-13

Arm-trunk coordination during the initiation of displacement in manual wheelchair is a complex task. The objective of this work is to study the arm-trunk coordination by measuring anticipatory and compensatory postural adjustments. Nine healthy subjects participated in the study after being trained in manual wheelchair. They were asked to initiate a displacement in manual wheelchair in three directions (forward vs. left vs. right), with two speeds (spontaneous vs. maximum) and with two initial hand's positions (hands on thighs vs. hands on handrails). Muscular activities in the trunk (postural component) and the arms (focal component) were recorded bilaterally. The results show two strategies for trunk control: An anticipatory adjustment strategy and a compensatory adjustment strategy with a dominance of compensation. These two strategies are influenced by the finalities of displacement in terms of speed and direction depending on the hands positions. Arm-trunk coordination is characterized by an adaptability of anticipatory and compensatory postural adjustments. The study of this type of coordination for subjects with different levels of spinal cord injury could be used to predict the forthcoming displacement and thus assist the user in a complex task. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ergonomic study on wrist posture when using laparoscopic tools in four different techniques regarding minimally invasive surgery.

Science.gov (United States)

Bartnicka, Joanna; Zietkiewicz, Agnieszka A; Kowalski, Grzegorz J

2018-03-19

With reference to four different minimally invasive surgery (MIS) cholecystectomy the aims were: to recognize the factors influencing dominant wrist postures manifested by the surgeon; to detect risk factors involved in maintaining deviated wrist postures; to compare the wrist postures of surgeons while using laparoscopic tools. Video films were recorded during live surgeries. The films were synchronized with wrist joint angles obtained from wireless electrogoniometers placed on the surgeon's hand. The analysis was conducted for five different laparoscopic tools used during all surgical techniques. The most common wrist posture was extension. In the case of one laparoscopic tool, the mean values defining extended wrist posture were distinct in all four surgical techniques. For one type of surgical technique, considered to be the most beneficial for patients, more extreme postures were noticed regarding all laparoscopic tools. We recognized a new factor, apart from the tool's handle design, that influences extreme and deviated wrist postures. It involves three areas of task specification including the type of action, type of motion patterns and motion dynamism. The outcomes proved that the surgical technique which is most beneficial for the patient imposes the greatest strain on the surgeon's wrist.

Effect of posture on hip joint moment during pregnancy, while performing a standing task.

Science.gov (United States)

Paul, J A; Sallé, H; Frings-Dresen, M H W

1996-03-01

In this paper the combined effect on reactive hip joint moment due to changes in (1) segment mass, (2) trunk centre of mass, and (3) working posture during pregnancy was estimated, and the relative contributions of these three changes to the change in the moment were assessed. The situation studied concerned standing work at a table. Sixteen women were studied monthly during pregnancy. The working posture was assessed by two-dimensional photographic posture recording and description. Body dimensions were measured to assess segment characteristics. A two-dimensional static model was used to estimate the reactive hip joint moment at 10, 20, 30 and 40 weeks of pregnancy. Between 10 and 40 weeks of pregnancy the moment increase was 52 Nm, i.e. the load at 40 weeks of pregnancy is 2.8 times the load at 10 weeks of pregnancy. On average half of this increase was due to postural changes. Changes in segment mass, trunk centre of mass, and the interaction between the three changes accounted for rougly 10, 20 and 15% of the load increase respectively. The increase in reactive hip joint moment may be minimized by preventing adverse postural changes, and optimizing the posture to reduce the contribution of changes in body weight (distribution).

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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

2018-01-29

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

Body posture modulates action perception.

Science.gov (United States)

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

2013-04-03

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

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.

Temporal parameter change of human postural control ability during upright swing using recursive least square method

Science.gov (United States)

Goto, Akifumi; Ishida, Mizuri; Sagawa, Koichi

2010-01-01

The purpose of this study is to derive quantitative assessment indicators of the human postural control ability. An inverted pendulum is applied to standing human body and is controlled by ankle joint torque according to PD control method in sagittal plane. Torque control parameters (KP: proportional gain, KD: derivative gain) and pole placements of postural control system are estimated with time from inclination angle variation using fixed trace method as recursive least square method. Eight young healthy volunteers are participated in the experiment, in which volunteers are asked to incline forward as far as and as fast as possible 10 times over 10 [s] stationary intervals with their neck joint, hip joint and knee joint fixed, and then return to initial upright posture. The inclination angle is measured by an optical motion capture system. Three conditions are introduced to simulate unstable standing posture; 1) eyes-opened posture for healthy condition, 2) eyes-closed posture for visual impaired and 3) one-legged posture for lower-extremity muscle weakness. The estimated parameters Kp, KD and pole placements are applied to multiple comparison test among all stability conditions. The test results indicate that Kp, KD and real pole reflect effect of lower-extremity muscle weakness and KD also represents effect of visual impairment. It is suggested that the proposed method is valid for quantitative assessment of standing postural control ability.

Automatic postural response systems in individuals with congenital total blindness.

Science.gov (United States)

Nakata, H; Yabe, K

2001-07-01

This study examined the effects of the absence of vision from birth on automatic postural responses to platform displacements during stance. Postural responses were induced by producing randomly four types of perturbations which consisted of forward and backward translations, and toe up and down rotations. Nine congenitally totally blind and nine sighted adults served as subjects. EMG signals were recorded from four muscles in the right leg, and reaction time to somatosensory stimuli generated by platform displacements was measured by pushing a hand-held button. To assess the ability to control postural balance, the root mean square (RMS) values for lateral and antero-posterior sway before, during, and after perturbations were calculated. The EMG amplitude in the gastrocnemius muscle of a blind subject was smaller than that of a sighted subject with eyes closed. No significant differences were found between blind and sighted subjects in EMG latencies of the lower extremity muscles in response to perturbations. The blind subjects had significantly faster reaction times to somatosensory stimuli triggered by platform displacements, but in toe down rotations no significant difference was found between blind and sighted subjects. The difference in the EMG latencies and reaction times between the two groups suggests that blindness from birth may not affect the spinal stretch reflex, but may affect a volitional act mediated through the motor cortex. There were also no significant differences in the RMS values for postural sway between blind and sighted subjects with eyes open or closed, although blind subjects swayed more after backward translations than did sighted subjects with eyes open. Results suggest that the ability to control postural balance during perturbations was not affected by vision loss from birth. Our findings suggest that the automatic postural response systems of humans are unaffected by the absence of vision from birth and are rather hard wired.

Comparison of organ doses in human phantoms: variations due to body size and posture

International Nuclear Information System (INIS)

Feng, Xu; Xiang-Hong, Jia; Xue-Jun, Yu; Zhan-Chun, Pan; Qian, Liu; Chun-Xin, Yang

2017-01-01

Organ dose calculations performed using human phantoms can provide estimates of astronauts' health risks due to cosmic radiation. However, the characteristics of such phantoms strongly affect the estimation precision. To investigate organ dose variations with body size and posture in human phantoms, a non-uniform rational B-spline boundary surfaces model was constructed based on cryo-section images. This model was used to establish four phantoms with different body size and posture parameters, whose organs parameters were changed simultaneously and which were voxelised with 4x4x4 mm"3 resolution. Then, using Monte Carlo transport code, the organ doses caused by ≤500 MeV isotropic incident protons were calculated. The dose variations due to body size differences within a certain range were negligible, and the doses received in crouching and standing-up postures were similar. Therefore, a standard Chinese phantom could be established, and posture changes cannot effectively protect astronauts during solar particle events. (authors)

The effect of hand position on perceived finger orientation in left- and right-handers.

Science.gov (United States)

Fraser, Lindsey E; Harris, Laurence R

2017-12-01

In the absence of visual feedback, the perceived orientation of the fingers is systematically biased. In right-handers these biases are asymmetrical between the left and right hands in the horizontal plane and may reflect common functional postures for the two hands. Here we compared finger orientation perception in right- and left-handed participants for both hands, across various hand positions in the horizontal plane. Participants rotated a white line on a screen optically superimposed over their hand to indicate the perceived position of the finger that was rotated to one of seven orientations with the hand either aligned with the body midline, aligned with the shoulder, or displaced by twice the shoulder-to-midline distance from the midline. We replicated the asymmetric pattern of biases previously reported in right-handed participants (left hand biased towards an orientation ~30° inward, right hand ~10° inward). However, no such asymmetry was found for left-handers, suggesting left-handers may use different strategies when mapping proprioception to body or space coordinates and/or have less specialization of function between the hands. Both groups' responses rotated further outward as distance of the hand from the body midline increased, consistent with other research showing spatial orientation estimates diverge outward in the periphery. Finally, for right-handers, precision of responses was best when the hand was aligned with the shoulder compared to the other two conditions. These results highlight the unique role of hand dominance and hand position in perception of finger orientation, and provide insight into the proprioceptive position sense of the upper limbs.

Systematic feasibility analysis of a quantitative elasticity estimation for breast anatomy using supine/prone patient postures.

Science.gov (United States)

Hasse, Katelyn; Neylon, John; Sheng, Ke; Santhanam, Anand P

2016-03-01

Breast elastography is a critical tool for improving the targeted radiotherapy treatment of breast tumors. Current breast radiotherapy imaging protocols only involve prone and supine CT scans. There is a lack of knowledge on the quantitative accuracy with which breast elasticity can be systematically measured using only prone and supine CT datasets. The purpose of this paper is to describe a quantitative elasticity estimation technique for breast anatomy using only these supine/prone patient postures. Using biomechanical, high-resolution breast geometry obtained from CT scans, a systematic assessment was performed in order to determine the feasibility of this methodology for clinically relevant elasticity distributions. A model-guided inverse analysis approach is presented in this paper. A graphics processing unit (GPU)-based linear elastic biomechanical model was employed as a forward model for the inverse analysis with the breast geometry in a prone position. The elasticity estimation was performed using a gradient-based iterative optimization scheme and a fast-simulated annealing (FSA) algorithm. Numerical studies were conducted to systematically analyze the feasibility of elasticity estimation. For simulating gravity-induced breast deformation, the breast geometry was anchored at its base, resembling the chest-wall/breast tissue interface. Ground-truth elasticity distributions were assigned to the model, representing tumor presence within breast tissue. Model geometry resolution was varied to estimate its influence on convergence of the system. A priori information was approximated and utilized to record the effect on time and accuracy of convergence. The role of the FSA process was also recorded. A novel error metric that combined elasticity and displacement error was used to quantify the systematic feasibility study. For the authors' purposes, convergence was set to be obtained when each voxel of tissue was within 1 mm of ground-truth deformation. The authors

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

Science.gov (United States)

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

2015-07-01

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

Take a stand on your decisions, or take a sit: posture does not affect risk preferences in an economic task

Directory of Open Access Journals (Sweden)

Megan K. O’Brien

2014-07-01

Full Text Available Physiological and emotional states can affect our decision-making processes, even when these states are seemingly insignificant to the decision at hand. We examined whether posture and postural threat affect decisions in a non-related economic domain. Healthy young adults made a series of choices between economic lotteries in various conditions, including changes in body posture (sitting vs. standing and changes in elevation (ground level vs. atop a 0.8-meter-high platform. We compared three metrics between conditions to assess changes in risk-sensitivity: frequency of risky choices, and parameter fits of both utility and probability weighting parameters using cumulative prospect theory. We also measured skin conductance level to evaluate physiological response to the postural threat. Our results demonstrate that body posture does not significantly affect decision making. Secondly, despite increased skin conductance level, economic risk-sensitivity was unaffected by increased threat. Our findings indicate that economic choices are fairly robust to the physiological and emotional changes that result from posture or postural threat.

Effect of forearm axially rotated posture on shoulder load and shoulder abduction / flexion angles in one-armed arrest of forward falls.

Science.gov (United States)

Hsu, Hsiu-Hao; Chou, You-Li; Lou, Shu-Zon; Huang, Ming-Jer; Chou, Paul Pei-Hsi

2011-03-01

Falling onto the outstretched hand is the most common cause of upper extremity injury. This study develops an experimental model for evaluating the shoulder load during a simulated forward fall onto one hand with three different forearm axially rotated postures, and examines the shoulder abduction angle and shoulder flexion angle in each case. Fifteen healthy young male subjects with an average age of 23.7 years performed a series of one-armed arrests from a height of 5 cm onto a force plate. The kinematics and kinetics of the upper extremity were analyzed for three different forearm postures, namely 45° externally rotated, non-rotated, and 45° internally rotated. The shoulder joint load and shoulder abduction/flexion angles were significantly dependent on the rotational posture of the forearm. The shoulder medio-lateral shear forces in the externally rotated group were found to be 1.61 and 2.94 times higher than those in the non-rotated and internally rotated groups, respectively. The shoulder flexion angles in the externally rotated, non-rotated and internally rotated groups were 0.6°, 8.0° and 19.2°, respectively, while the corresponding shoulder abduction angles were 6.1°, 34.1° and 46.3°, respectively. In falls onto the outstretched hand, an externally rotated forearm posture should be avoided in order to reduce the medio-lateral shear force acting on the shoulder joint. In falls of this type, a 45° internally rotated forearm posture represents the most effective fall strategy in terms of minimizing the risk of upper extremity injuries. Copyright © 2010 Elsevier Ltd. All rights reserved.

Principal components analysis based control of a multi-dof underactuated prosthetic hand

Directory of Open Access Journals (Sweden)

Magenes Giovanni

2010-04-01

Full Text Available Abstract Background Functionality, controllability and cosmetics are the key issues to be addressed in order to accomplish a successful functional substitution of the human hand by means of a prosthesis. Not only the prosthesis should duplicate the human hand in shape, functionality, sensorization, perception and sense of body-belonging, but it should also be controlled as the natural one, in the most intuitive and undemanding way. At present, prosthetic hands are controlled by means of non-invasive interfaces based on electromyography (EMG. Driving a multi degrees of freedom (DoF hand for achieving hand dexterity implies to selectively modulate many different EMG signals in order to make each joint move independently, and this could require significant cognitive effort to the user. Methods A Principal Components Analysis (PCA based algorithm is used to drive a 16 DoFs underactuated prosthetic hand prototype (called CyberHand with a two dimensional control input, in order to perform the three prehensile forms mostly used in Activities of Daily Living (ADLs. Such Principal Components set has been derived directly from the artificial hand by collecting its sensory data while performing 50 different grasps, and subsequently used for control. Results Trials have shown that two independent input signals can be successfully used to control the posture of a real robotic hand and that correct grasps (in terms of involved fingers, stability and posture may be achieved. Conclusions This work demonstrates the effectiveness of a bio-inspired system successfully conjugating the advantages of an underactuated, anthropomorphic hand with a PCA-based control strategy, and opens up promising possibilities for the development of an intuitively controllable hand prosthesis.

The association between head and cervical posture and temporomandibular disorders: a systematic review.

Science.gov (United States)

Olivo, Susan Armijo; Bravo, Jaime; Magee, David J; Thie, Norman M R; Major, Paul W; Flores-Mir, Carlos

2006-01-01

To carry out a systematic review to assess the evidence concerning the association between head and cervical posture and temporomandibular disorders (TMD). A search of Medline, Pubmed, Embase, Web of Science, Lilacs, and Cochrane Library databases was conducted in all languages with the help of a health sciences librarian. Key words used in the search were posture, head posture, cervical spine or neck, vertebrae, cervical lordosis, craniomandibular disorders or temporomandibular disorders, temporomandibular disorders, and orofacial pain or facial pain. Abstracts which appeared to fulfill the initial selection criteria were selected by consensus. The original articles were retrieved and evaluated to ensure they met the inclusion criteria. A methodological checklist was used to evaluate the quality of the selected articles and their references were hand-searched for possible missing articles. Twelve studies met all inclusion criteria and were analyzed in detail for their methodology and information quality. Nine articles that analyzed the association between head posture and TMD included patients with mixed TMD diagnosis; 1 article differentiated among muscular, articular, and mixed symptomatology; and 3 articles analyzed information from patients with only articular problems. Finally, 2 studies evaluated the association between head posture and TMD in patients with muscular TMD. Several methodological defects were noted in the 12 studies. Since most of the studies included in this systematic review were of poor methodological quality, the findings of the studies should be interpreted with caution. The association between intra-articular and muscular TMD and head and cervical posture is still unclear, and better controlled studies with comprehensive TMD diagnoses, greater sample sizes, and objective posture evaluation are necessary.

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

Science.gov (United States)

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

2017-01-01

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

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

Directory of Open Access Journals (Sweden)

Geneviève Sirois-Leclerc

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

Role of brain hemispheric dominance in anticipatory postural control strategies.

Science.gov (United States)

Cioncoloni, David; Rosignoli, Deborah; Feurra, Matteo; Rossi, Simone; Bonifazi, Marco; Rossi, Alessandro; Mazzocchio, Riccardo

2016-07-01

Most of the cerebral functions are asymmetrically represented in the two hemispheres. Moreover, dexterity and coordination of the distal segment of the dominant limbs depend on cortico-motor lateralization. In this study, we investigated whether postural control may be also considered a lateralized hemispheric brain function. To this aim, 15 young subjects were tested in standing position by measuring center of pressure (COP) shifts along the anteroposterior axis (COP-Y) during dynamic posturography before and after continuous Theta Burst Stimulation (cTBS) intervention applied to the dominant or non-dominant M1 hand area as well as to the vertex. We show that when subjects were expecting a forward platform translation, the COP-Y was positioned significantly backward or forward after dominant or non-dominant M1 stimulation, respectively. We postulate that cTBS applied on M1 may have disrupted the functional connectivity between intra- and interhemispheric areas implicated in the anticipatory control of postural stability. This study suggests a functional asymmetry between the two homologous primary motor areas, with the dominant hemisphere playing a critical role in the selection of the appropriate postural control strategy.

Coordination of hand shape.

Science.gov (United States)

Pesyna, Colin; Pundi, Krishna; Flanders, Martha

2011-03-09

The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness.

Guide to Good Posture

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

Cassavaugh Nicholas D

2011-10-01

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

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

Science.gov (United States)

Ustinova, Ksenia I; Leonard, Wesley A; Cassavaugh, Nicholas D; Ingersoll, Christopher D

2011-10-31

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

Older adults utilize less efficient postural control when performing pushing task.

Science.gov (United States)

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

2015-12-01

The ability to maintain balance deteriorates with increasing age. The aim was to investigate the role of age in generation of anticipatory (APA) and compensatory (CPA) postural adjustments during pushing an object. Older (68.8 ± 1.0 years) and young adults (30.1 ± 1.4 years) participated in the experiment involving pushing an object (a pendulum attached to the ceiling) using both hands. Electrical activity of six leg and trunk muscles and displacements of the center of pressure (COP) were recorded and analyzed during the APA and CPA phases. The onset time, integrals of muscle activity, and COP displacements were determined. In addition, the indexes of co-activation and reciprocal activation of muscles for the shank, thigh, and trunk segments were calculated. Older adults, compared to young adults, showed less efficient postural control seen as delayed anticipatory muscle onset times and delayed COP displacements. Moreover, older adults used co-activation of muscles during the CPA phase while younger subjects utilized reciprocal activation of muscles. The observed diminished efficiency of postural control during both anticipatory and compensatory postural adjustments observed in older adults might predispose them to falls while performing tasks involving pushing. The outcome provides a background for future studies focused on the optimization of the daily activities of older adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Jacek Wilczyński

2017-08-01

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

Three components of postural control associated with pushing in symmetrical and asymmetrical stance.

Science.gov (United States)

Lee, Yun-Ju; Aruin, Alexander S

2013-07-01

A number of occupational and leisure activities that involve pushing are performed in symmetrical or asymmetrical stance. The goal of this study was to investigate early postural adjustments (EPAs), anticipatory postural adjustments (APAs), and compensatory postural adjustments (CPAs) during pushing performed while standing. Ten healthy volunteers stood in symmetrical stance (with feet parallel) or in asymmetrical stance (staggered stance with one foot forward) and were instructed to use both hands to push forward the handle of a pendulum attached to the ceiling. Bilateral EMG activity of the trunk and leg muscles and the center of pressure (COP) displacements in the anterior-posterior (AP) and medial-lateral (ML) directions were recorded and analyzed during the EPAs, APAs, and CPAs. The EMG activity and the COP displacement were different between the symmetrical and asymmetrical stance conditions. The COP displacements in the ML direction were significantly larger in staggered stance than in symmetrical stance. In staggered stance, the EPAs and APAs in the thigh muscles of the backward leg were significantly larger, and the CPAs were smaller than in the forward leg. There was no difference in the EMG activity of the trunk muscles between the stance conditions. The study outcome confirmed the existence of the three components of postural control (EPAs, APAs, and CPAs) in pushing. Moreover, standing asymmetrically was associated with asymmetrical patterns of EMG activity in the lower extremities reflecting the stance-related postural control during pushing. The study outcome provides a basis for studying postural control during other daily activities involving pushing.

Phase-dependent organization of postural adjustments associated with arm movements while walking.

Science.gov (United States)

Nashner, L M; Forssberg, H

1986-06-01

This study examines the interactions between anteroposterior postural responses and the control of walking in human subjects. In the experimental paradigm, subjects walked upon a treadmill, gripping a rigid handle with one hand. Postural responses at different phases of stepping were elicited by rapid arm pulls or pushes against the handle. During arm movements, EMG's recorded the activity of representative arm, ankle, and thigh segment muscles. Strain gauges in the handle measured the force of the arm movement. A Selspot II system measured kinematics of the stepping movements. The duration of support and swing phases were marked by heel and toe switches in the soles of the subjects' shoes. In the first experiment, subjects were instructed to pull on the handle at their own pace. In these trials all subjects preferred to initiate pulls near heel strikes. Next, when instructed to pull as rapidly as possible in response to tone stimuli, reaction times were similar for all phases of the step cycle. Leg muscle responses associated with arm pulls and pushes, referred to as "postural activations," were directionally specific and preceded arm muscle activity. The temporal order and spatial distribution of postural activations in the muscles of the support leg were similar when arm pull movements occurred while the subject was standing in place and after heel strike while walking. Activations began in the ankle and radiated proximally to the thigh and then the arm. Activations of swing leg muscles were also directionally specific and involved flexion and forward or backward thrust of the limb. When arm movements were initiated during transitions from support by one leg to the other, patterns of postural activations were altered. Alterations usually occurred 10-20 ms before hell strikes and involved changes in the timing and sometimes the spatial structure of postural activations. Postural activation patterns are similar during in-place standing and during the support phase

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

Directory of Open Access Journals (Sweden)

Agnieszka Jankowicz-Szymanska

2016-07-01

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

Fatiguing exercise intensity influences the relationship between parameters reflecting neuromuscular function and postural control variables.

Directory of Open Access Journals (Sweden)

Sébastien Boyas

Full Text Available The purpose of this study was to investigate the influence of fatiguing exercise intensity on the nature and extent of fatigue-induced changes in neuromuscular function and postural stability in quiet standing. We also explored the contribution of selected neuromuscular mechanisms involved in force production to postural stability impairment observed following fatigue using an approach based on multivariate regressions. Eighteen young subjects performed 30-s postural trials on one leg with their eyes closed. Postural trials were performed before and after fatiguing exercises of different intensities: 25, 50 and 75% of maximal isometric plantarflexor torque. Fatiguing exercises consisted of sustaining a plantarflexor isometric contraction at the target intensity until task failure. Maximal isometric plantarflexor torque, electromyographic activity of plantarflexor and dorsiflexor muscles, activation level (twitch interpolation technique and twitch contractile properties of plantarflexors were used to characterize neuromuscular function. The 25% exercise was associated with greater central fatigue whereas the 50 and 75% exercises involved mostly peripheral fatigue. However, all fatiguing exercises induced similar alterations in postural stability, which was unexpected considering previous literature. Stepwise multiple regression analyses showed that fatigue-related changes in selected parameters related to neuromuscular function could explain more than half (0.51≤R(2≤0.82 of the changes in postural variables for the 25% exercise. On the other hand, regression models were less predictive (0.17≤R(2≤0.73 for the 50 and 75% exercises. This study suggests that fatiguing exercise intensity does not influence the extent of postural stability impairment, but does influence the type of fatigue induced and the neuromuscular function predictors explaining changes in postural variables.

Distinct contribution of the parietal and temporal cortex to hand configuration and contextual judgements about tools.

Science.gov (United States)

Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

2013-09-01

Neuropsychological studies showed that manipulatory and semantic knowledge can be independently impaired in patients with upper-limb apraxia, leading to different tool use disorders. The present study aimed to dissociate the brain regions involved in judging the hand configuration or the context associated to tool use. We focussed on the left supramarginalis gyrus (SMG) and left middle temporal gyrus (MTG), whose activation, as evidenced by functional magnetic resonance imaging (fMRI) studies, suggests that they may play a critical role in tool use. The distinctive location of SMG in the dorsal visual stream led us to postulate that this parietal region could play a role in processing incoming information about tools to shape hand posture. In contrast, we hypothesized that MTG, because of its interconnections with several cortical areas involved in semantic memory, could contribute to retrieving semantic information necessary to create a contextual representation of tool use. To test these hypotheses, we used neuronavigated transcranial magnetic stimulation (TMS) to interfere transiently with the function of either left SMG or left MTG in healthy participants performing judgement tasks about either hand configuration or context of tool use. We found that SMG virtual lesions impaired hand configuration but not contextual judgements, whereas MTG lesions selectively interfered with judgements about the context of tool use while leaving hand configuration judgements unaffected. This double dissociation demonstrates that the ability to infer a context of use or a hand posture from tool perception relies on distinct processes, performed in the temporal and parietal regions. The present findings suggest that tool use disorders caused by SMG lesions will be characterized by difficulties in selecting the appropriate hand posture for tool use, whereas MTG lesions will yield difficulties in using tools in the appropriate context. Copyright © 2012. Published by Elsevier Ltd.

A four-dimensional virtual hand brain-machine interface using active dimension selection.

Science.gov (United States)

Rouse, Adam G

2016-06-01

Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s(-1) for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

POSTUR KERJA DAN RISIKO LOW BACK PAIN PADA PEKERJA PASIRAN

Directory of Open Access Journals (Sweden)

Denny Nurkertamanda

2017-10-01

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

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

Science.gov (United States)

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

2016-12-01

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

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

DEFF Research Database (Denmark)

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

2011-01-01

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

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

2017-04-01

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

surgery of the hand in infants with cerebral palsy* 655

African Journals Online (AJOL)

1971-06-19

Jun 19, 1971 ... cerebral palsy is by re-education-physical, occupational, speech and drug therapy."· Orthopaedic surgery is usually considered as an adjunct to therapy'" and is indicated only for its value ... than long-continued postural training and stretching.",13 ... In each child in this series, the hand on the affected side.

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

Science.gov (United States)

Dirlich, Thomas

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

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

Science.gov (United States)

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

2014-11-01

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

[Maternal posture and its influence on birthweight].

Science.gov (United States)

Takito, Monica Yuri; Benício, Maria Helena D'Aquino; Latorre, Maria do Rosário Dias de Oliveira

2005-06-01

To analyze the relationship between maternal posture/physical activity and inadequate birthweight. Prospective cohort study involving 152 pregnant women from a public low-risk antenatal care facility. Three interviews evaluating the frequency of physical activity were administered to each pregnant woman during gestation. Birthweight (inadequate when or =3,000 g) was the dependent variable and the frequency of physical activity the independent variable. Statistical analysis was performed using logistic univariate analysis and multiple regression controlling for schooling, smoking, living with spouse, and baseline nutritional status. The practice of walking for at least 50 minutes during the first period of pregnancy was identified as a protective factor against inadequate birthweight (adjusted OR=0.44; 95% CI: 0.20-0.98). Standing for 2.5 hours or longer during the second semester of pregnancy was associated with increased risk (adjusted OR=3.23; 95% CI: 1.30-7.99). Dose-response relationships were identified for washing clothing by hand and cooking (p-value for linear trend clothing during the second trimester of gestation remained statistically significant. Our results show the importance of medical orientation regarding posture and physical activity during antenatal care, aiming at the reduction of inadequate birthweight.

Postural control of typical developing boys during the transition from double-leg stance to single-leg stance.

Science.gov (United States)

Deschamps, Kevin; Staes, Filip; Peerlinck, Kathelijne; Van Geet, Kristel; Hermans, Cedric; Lobet, Sebastien

2017-02-01

Literature is lacking information about postural control performance of typically developing children during a transition task from double-leg stance to single-leg stance. The purpose of the present study was therefore to evaluate the clinical feasibility of a transition task in typical developing age groups as well as to study the correlation between associated balance measures and age.Thirty-three typically developing boys aged 6-20 years performed a standard transition task from DLS to SLS with eyes open (EO) and eyes closed (EC). Balance features derived from the center of pressure displacement captured by a single force platform were correlated with age on the one hand and considered for differences in the perspective of limb dominance on the other hand.All TDB (typically developing boys) were able to perform the transition task with EO. With respect to EC condition, all TDB from the age group 6-7 years and the youngest of the age group 8-12 years (N = 4) were unable to perform the task. No significant differences were observed between the balance measures of the dominant and non-dominant limbs.With respect to EO condition, correlation analyses indicated that time to new stability point (TNSP) as well as the sway measure after this TNSP were correlated with age (p postural balance of typically developing children during walking, running, sit-to-stand, and bipodal and unipodal stance has been well documented in the literature. • These reference data provided not only insight into the maturation process of the postural control system, but also served in diagnosing and managing functional repercussions of neurological and orthopedic pathologies. What is New: • Objective data regarding postural balance of typical developing children during a transition task from double-leg stance to single-leg stance. • Insight into the role of maturation on the postural control system.

Components of Standing Postural Control Evaluated in Pediatric Balance Measures: A Scoping Review.

Science.gov (United States)

Sibley, Kathryn M; Beauchamp, Marla K; Van Ooteghem, Karen; Paterson, Marie; Wittmeier, Kristy D

2017-10-01

To identify measures of standing balance validated in pediatric populations, and to determine the components of postural control captured in each tool. Electronic searches of MEDLINE, Embase, and CINAHL databases using key word combinations of postural balance/equilibrium, psychometrics/reproducibility of results/predictive value of tests, and child/pediatrics; gray literature; and hand searches. Inclusion criteria were measures with a stated objective to assess balance, with pediatric (≤18y) populations, with at least 1 psychometric evaluation, with at least 1 standing task, with a standardized protocol and evaluation criteria, and published in English. Two reviewers independently identified studies for inclusion. There were 21 measures included. Two reviewers extracted descriptive characteristics, and 2 investigators independently coded components of balance in each measure using a systems perspective for postural control, an established framework for balance in pediatric populations. Components of balance evaluated in measures were underlying motor systems (100% of measures), anticipatory postural control (72%), static stability (62%), sensory integration (52%), dynamic stability (48%), functional stability limits (24%), cognitive influences (24%), verticality (9%), and reactive postural control (0%). Assessing children's balance with valid and comprehensive measures is important for ensuring development of safe mobility and independence with functional tasks. Balance measures validated in pediatric populations to date do not comprehensively assess standing postural control and omit some key components for safe mobility and independence. Existing balance measures, that have been validated in adult populations and address some of the existing gaps in pediatric measures, warrant consideration for validation in children. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Neurofeedback-induced facilitation of the supplementary motor area affects postural stability.

Science.gov (United States)

Fujimoto, Hiroaki; Mihara, Masahito; Hattori, Noriaki; Hatakenaka, Megumi; Yagura, Hajime; Kawano, Teiji; Miyai, Ichiro; Mochizuki, Hideki

2017-10-01

Near-infrared spectroscopy-mediated neurofeedback (NIRS-NFB) is a promising therapeutic intervention for patients with neurological diseases. Studies have shown that NIRS-NFB can facilitate task-related cortical activation and induce task-specific behavioral changes. These findings indicate that the effect of neuromodulation depends on local cortical function. However, when the target cortical region has multiple functions, our understanding of the effects is less clear. This is true in the supplementary motor area (SMA), which is involved both in postural control and upper-limb movement. To address this issue, we investigated the facilitatory effect of NIRS SMA neurofeedback on cortical activity and behavior, without any specific task. Twenty healthy individuals participated in real and sham neurofeedback. Balance and hand dexterity were assessed before and after each NIRS-NFB session. We found a significant interaction between assessment periods (pre/post) and condition (real/sham) with respect to balance as assessed by the center of the pressure path length but not for hand dexterity as assessed by the 9-hole peg test. SMA activity only increased during real neurofeedback. Our findings indicate that NIRS-NFB itself has the potential to modulate focal cortical activation, and we suggest that it be considered a therapy to facilitate the SMA for patients with postural impairment.

LOCALIZATION AND RECOGNITION OF DYNAMIC HAND GESTURES BASED ON HIERARCHY OF MANIFOLD CLASSIFIERS

OpenAIRE

M. Favorskaya; A. Nosov; A. Popov

2015-01-01

Generally, the dynamic hand gestures are captured in continuous video sequences, and a gesture recognition system ought to extract the robust features automatically. This task involves the highly challenging spatio-temporal variations of dynamic hand gestures. The proposed method is based on two-level manifold classifiers including the trajectory classifiers in any time instants and the posture classifiers of sub-gestures in selected time instants. The trajectory classifiers contain skin dete...

Reference Values for Human Posture Measurements Based on Computerized Photogrammetry: A Systematic Review.

Science.gov (United States)

Macedo Ribeiro, Ana Freire; Bergmann, Anke; Lemos, Thiago; Pacheco, Antônio Guilherme; Mello Russo, Maitê; Santos de Oliveira, Laura Alice; de Carvalho Rodrigues, Erika

The main objective of this study was to review the literature to identify reference values for angles and distances of body segments related to upright posture in healthy adult women with the Postural Assessment Software (PAS/SAPO). Electronic databases (BVS, PubMed, SciELO and Scopus) were assessed using the following descriptors: evaluation, posture, photogrammetry, physical therapy, postural alignment, postural assessment, and physiotherapy. Studies that performed postural evaluation in healthy adult women with PAS/SAPO and were published in English, Portuguese and Spanish, between the years 2005 and 2014 were included. Four studies met the inclusion criteria. Data from the included studies were grouped to establish the statistical descriptors (mean, variance, and standard deviation) of the body angles and distances. A total of 29 variables were assessed (10 in the anterior views, 16 in the lateral right and left views, and 3 in the posterior views), and its respective mean and standard deviation were calculated. Reference values for the anterior and posterior views showed no symmetry between the right and left sides of the body in the frontal plane. There were also small differences in the calculated reference values for the lateral view. The proposed reference values for quantitative evaluation of the upright posture in healthy adult women estimated in the present study using PAS/SAPO could guide future studies and help clinical practice. Copyright © 2017. Published by Elsevier Inc.

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

Science.gov (United States)

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

2018-01-01

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

Common postural defects among music students.

Science.gov (United States)

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

2015-07-01

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

A biometric authentication model using hand gesture images.

Science.gov (United States)

Fong, Simon; Zhuang, Yan; Fister, Iztok; Fister, Iztok

2013-10-30

A novel hand biometric authentication method based on measurements of the user's stationary hand gesture of hand sign language is proposed. The measurement of hand gestures could be sequentially acquired by a low-cost video camera. There could possibly be another level of contextual information, associated with these hand signs to be used in biometric authentication. As an analogue, instead of typing a password 'iloveu' in text which is relatively vulnerable over a communication network, a signer can encode a biometric password using a sequence of hand signs, 'i' , 'l' , 'o' , 'v' , 'e' , and 'u'. Subsequently the features from the hand gesture images are extracted which are integrally fuzzy in nature, to be recognized by a classification model for telling if this signer is who he claimed himself to be, by examining over his hand shape and the postures in doing those signs. It is believed that everybody has certain slight but unique behavioral characteristics in sign language, so are the different hand shape compositions. Simple and efficient image processing algorithms are used in hand sign recognition, including intensity profiling, color histogram and dimensionality analysis, coupled with several popular machine learning algorithms. Computer simulation is conducted for investigating the efficacy of this novel biometric authentication model which shows up to 93.75% recognition accuracy.

Thermoregulatory postures limit antipredator responses in peafowl.

Science.gov (United States)

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

2018-01-05

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

Thermoregulatory postures limit antipredator responses in peafowl

Directory of Open Access Journals (Sweden)

Jessica L. Yorzinski

2018-01-01

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

Imaging Posture Veils Neural Signals

Directory of Open Access Journals (Sweden)

Robert T Thibault

2016-10-01

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

COMPLEX TREATMENT OF PATIENTS WITH POSTURAL PHOBIC DIZZINESS

Directory of Open Access Journals (Sweden)

M. V. Romanоva

2013-01-01

Full Text Available A total of 25 patients with postural phobic dizziness were examined. Somatic state and neurological status were assessed, neurovisualization and stabilometric investigation were carried out as well as a neuropsychological testing using estimation scales. The efficiency of complex rehabilitation was revealed including vestibular gymnastics, stabilometric training, psychotherapy, and pharmacotherapy in correction of psychoemotional disturbances. 

Postural Coordination during Socio-motor Improvisation.

Science.gov (United States)

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

2016-01-01

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

Postural coordination during socio-motor improvisation

Directory of Open Access Journals (Sweden)

Mathieu Gueugnon

2016-08-01

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

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

OpenAIRE

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

2005-01-01

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

Ergonomic assessment of the posture of surgeons performing endoscopic transurethral resections in urology

Directory of Open Access Journals (Sweden)

Sökeland Jürgen

2009-10-01

Full Text Available Abstract Background During transurethral endoscopic prostate and bladder operations the influence of an ergonomic redesign of the arrangement of the operation equipment - including the introduction of a video-assisted resection method ('monitor endoscopy' instead of directly viewing onto the operation area via the endoscope ('direct endoscopy' - was studied with respect to the postures of the surgeons. Methods Postures were analysed on the basis of video recordings of the surgeons performed in the operation theatre during live operations and subsequent visual posture estimation executed by an observer. In particular, head, trunk and arm positions were assigned to posture categories according to a newly developed posture classification schema. 10 urological operations with direct endoscopy and 9 with monitor endoscopy were included. Results Application of direct endoscopy coincides with distinct lateral and sagittal trunk and head inclinations, trunk torsion and strong forearm and upper arm elevations of the surgeons whereas operations with monitor endoscopy were performed with an almost upright head and trunk and hanging arms. The disadvantageous postures observed during direct endoscopy are mainly caused by the necessity to hold the endoscope continuously in close contact with the eye. Conclusion From an ergonomic point of view, application of the video-assisted resection method should be preferred in transurethral endoscopic operations in order to prevent awkward postures of the surgeons and to limit muscular strain and fatigue. Furthermore, the application of the monitor method enables the use of a chair equipped with back support and armrests and benefits the reduction of postural stress.

Evaluation of feedforward and feedback contributions to hand stiffness and variability in multijoint arm control.

Science.gov (United States)

He, Xin; Du, Yu-Fan; Lan, Ning

2013-07-01

The purpose of this study is to validate a neuromechanical model of the virtual arm (VA) by comparing emerging behaviors of the model to those of experimental observations. Hand stiffness of the VA model was obtained by either theoretical computation or simulated perturbations. Variability in hand position of the VA was generated by adding signal dependent noise (SDN) to the motoneuron pools of muscles. Reflex circuits of Ia, Ib and Renshaw cells were included to regulate the motoneuron pool outputs. Evaluation of hand stiffness and variability was conducted in simulations with and without afferent feedback under different patterns of muscle activations during postural maintenance. The simulated hand stiffness and variability ellipses captured the experimentally observed features in shape, magnitude and orientation. Steady state afferent feedback contributed significantly to the increase in hand stiffness by 35.75±16.99% in area, 18.37±7.80% and 16.15±7.15% in major and minor axes; and to the reduction of hand variability by 49.41±21.19% in area, 36.89±12.78% and 18.87±23.32% in major and minor axes. The VA model reproduced the neuromechanical behaviors that were consistent with experimental data, and it could be a useful tool for study of neural control of posture and movement, as well as for application to rehabilitation.

Hands of early primates.

Science.gov (United States)

Boyer, Doug M; Yapuncich, Gabriel S; Chester, Stephen G B; Bloch, Jonathan I; Godinot, Marc

2013-12-01

Questions surrounding the origin and early evolution of primates continue to be the subject of debate. Though anatomy of the skull and inferred dietary shifts are often the focus, detailed studies of postcrania and inferred locomotor capabilities can also provide crucial data that advance understanding of transitions in early primate evolution. In particular, the hand skeleton includes characteristics thought to reflect foraging, locomotion, and posture. Here we review what is known about the early evolution of primate hands from a comparative perspective that incorporates data from the fossil record. Additionally, we provide new comparative data and documentation of skeletal morphology for Paleogene plesiadapiforms, notharctines, cercamoniines, adapines, and omomyiforms. Finally, we discuss implications of these data for understanding locomotor transitions during the origin and early evolutionary history of primates. Known plesiadapiform species cannot be differentiated from extant primates based on either intrinsic hand proportions or hand-to-body size proportions. Nonetheless, the presence of claws and a different metacarpophalangeal [corrected] joint form in plesiadapiforms indicate different grasping mechanics. Notharctines and cercamoniines have intrinsic hand proportions with extremely elongated proximal phalanges and digit rays relative to metacarpals, resembling tarsiers and galagos. But their hand-to-body size proportions are typical of many extant primates (unlike those of tarsiers, and possibly Teilhardina, which have extremely large hands). Non-adapine adapiforms and omomyids exhibit additional carpal features suggesting more limited dorsiflexion, greater ulnar deviation, and a more habitually divergent pollex than observed plesiadapiforms. Together, features differentiating adapiforms and omomyiforms from plesiadapiforms indicate increased reliance on vertical prehensile-clinging and grasp-leaping, possibly in combination with predatory behaviors in

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

Science.gov (United States)

McFarland, Joshua C; Meyers, Ron A

2008-08-01

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

The influence of body posture on lithium clearance

DEFF Research Database (Denmark)

Kamper, A L; Strandgaard, S; Holstein-Rathlou, N H

1988-01-01

To establish appropriate standard circumstances for lithium clearance measurements, a study was undertaken in 12 healthy volunteers. In each subject, the glomerular filtration rate (GFR), as estimated by [51Cr]EDTA plasma clearance, and the renal clearances of lithium, sodium and potassium were...... during moderate physical activity. Hence, when renal tubular function is studied with the lithium clearance method, standardization of posture and physical activity is important. In such studies physical activity such as walking should particularly be avoided....... measured four times at 1-week intervals: two in the supine and one in the sitting position, and one when the subject was walking around. Glomerular filtration rate was not influenced by posture changes. On the contrary, lithium clearance, which in the supine position was 30 +/- 9 ml/min (1 SD), tended...

The influence of body posture on lithium clearance

DEFF Research Database (Denmark)

Kamper, A L; Strandgaard, S; Holstein-Rathlou, N H

1988-01-01

To establish appropriate standard circumstances for lithium clearance measurements, a study was undertaken in 12 healthy volunteers. In each subject, the glomerular filtration rate (GFR), as estimated by [51Cr]EDTA plasma clearance, and the renal clearances of lithium, sodium and potassium were...... measured four times at 1-week intervals: two in the supine and one in the sitting position, and one when the subject was walking around. Glomerular filtration rate was not influenced by posture changes. On the contrary, lithium clearance, which in the supine position was 30 +/- 9 ml/min (1 SD), tended...... during moderate physical activity. Hence, when renal tubular function is studied with the lithium clearance method, standardization of posture and physical activity is important. In such studies physical activity such as walking should particularly be avoided....

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

Science.gov (United States)

Paillard, Thierry

2017-01-01

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

Postural risk assessment of mechanised firewood processing.

Science.gov (United States)

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

2017-03-01

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

Muscular tension and body posture in relation to voice handicap and voice quality in teachers with persistent voice complaints.

Science.gov (United States)

Kooijman, P G C; de Jong, F I C R S; Oudes, M J; Huinck, W; van Acht, H; Graamans, K

2005-01-01

The aim of this study was to investigate the relationship between extrinsic laryngeal muscular hypertonicity and deviant body posture on the one hand and voice handicap and voice quality on the other hand in teachers with persistent voice complaints and a history of voice-related absenteeism. The study group consisted of 25 female teachers. A voice therapist assessed extrinsic laryngeal muscular tension and a physical therapist assessed body posture. The assessed parameters were clustered in categories. The parameters in the different categories represent the same function. Further a tension/posture index was created, which is the summation of the different parameters. The different parameters and the index were related to the Voice Handicap Index (VHI) and the Dysphonia Severity Index (DSI). The scores of the VHI and the individual parameters differ significantly except for the posterior weight bearing and tension of the sternocleidomastoid muscle. There was also a significant difference between the individual parameters and the DSI, except for tension of the cricothyroid muscle and posterior weight bearing. The score of the tension/posture index correlates significantly with both the VHI and the DSI. In a linear regression analysis, the combination of hypertonicity of the sternocleidomastoid, the geniohyoid muscles and posterior weight bearing is the most important predictor for a high voice handicap. The combination of hypertonicity of the geniohyoid muscle, posterior weight bearing, high position of the hyoid bone, hypertonicity of the cricothyroid muscle and anteroposition of the head is the most important predictor for a low DSI score. The results of this study show the higher the score of the index, the higher the score of the voice handicap and the worse the voice quality is. Moreover, the results are indicative for the importance of assessment of muscular tension and body posture in the diagnosis of voice disorders.

Dynamic genetic linkage of intermediate blood pressure phenotypes during postural adaptations in a founder population

Science.gov (United States)

Arenas, I. A.; Tremblay, J.; Deslauriers, B.; Sandoval, J.; Šeda, O.; Gaudet, D.; Merlo, E.; Kotchen, T.; Cowley, A. W.

2013-01-01

Blood pressure (BP) is a dynamic phenotype that varies rapidly to adjust to changing environmental conditions. Standing upright is a recent evolutionary trait, and genetic factors that influence postural adaptations may contribute to BP variability. We studied the effect of posture on the genetics of BP and intermediate BP phenotypes. We included 384 sib-pairs in 64 sib-ships from families ascertained by early-onset hypertension and dyslipidemia. Blood pressure, three hemodynamic and seven neuroendocrine intermediate BP phenotypes were measured with subjects lying supine and standing upright. The effect of posture on estimates of heritability and genetic covariance was investigated in full pedigrees. Linkage was conducted on 196 candidate genes by sib-pair analyses, and empirical estimates of significance were obtained. A permutation algorithm was implemented to study the postural effect on linkage. ADRA1A, APO, CAST, CORIN, CRHR1, EDNRB, FGF2, GC, GJA1, KCNB2, MMP3, NPY, NR3C2, PLN, TGFBR2, TNFRSF6, and TRHR showed evidence of linkage with any phenotype in the supine position and not upon standing, whereas AKR1B1, CD36, EDNRA, F5, MMP9, PKD2, PON1, PPARG, PPARGC1A, PRKCA, and RET were specifically linked to standing phenotypes. Genetic profiling was undertaken to show genetic interactions among intermediate BP phenotypes and genes specific to each posture. When investigators perform genetic studies exclusively on a single posture, important genetic components of BP are missed. Supine and standing BPs have distinct genetic signatures. Standardized maneuvers influence the results of genetic investigations into BP, thus reflecting its dynamic regulation. PMID:23269701

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2010-10-01

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

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

Science.gov (United States)

2011-01-01

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

Automated Assessment of Postural Stability (AAPS)

Science.gov (United States)

2016-10-01

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

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

Directory of Open Access Journals (Sweden)

Kubicki A

2012-02-01

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

Gait, posture and cognition in Parkinson's disease

Directory of Open Access Journals (Sweden)

Alessandra Ferreira Barbosa

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

Postural Control in Children with Autism.

Science.gov (United States)

Kohen-Raz, Reuven; And Others

1992-01-01

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

Human Posture Identification Using a MIMO Array

OpenAIRE

Dai Sasakawa; Naoki Honma; Takeshi Nakayama; Shoichi Iizuka

2018-01-01

The elderly are constantly in danger of falling and injuring themselves without anyone realizing it. A safety-monitoring system based on microwaves can ease these concerns. The authors have proposed safety-monitoring systems that use multiple-input multiple-output (MIMO) radar to localize persons by capturing their biological activities such as respiration. However, our studies to date have focused on localization, which is easier to achieve than an estimation of human postures. This paper pr...

Shape-estimation of human hand using polymer flex sensor and study of its application to control robot arm

International Nuclear Information System (INIS)

Lee, Jin Hyuck; Kim, Dae Hyun

2015-01-01

Ultrasonic inspection robot systems have been widely researched and developed for the real-time monitoring of structures such as power plants. However, an inspection robot that is operated in a simple pattern has limitations in its application to various structures in a plant facility because of the diverse and complicated shapes of the inspection objects. Therefore, accurate control of the robot is required to inspect complicated objects with high-precision results. This paper presents the idea that the shape and movement information of an ultrasonic inspector's hand could be profitably utilized for the accurate control of robot. In this study, a polymer flex sensor was applied to monitor the shape of a human hand. This application was designed to intuitively control an ultrasonic inspection robot. The movement and shape of the hand were estimated by applying multiple sensors. Moreover, it was successfully shown that a test robot could be intuitively controlled based on the shape of a human hand estimated using polymer flex sensors.

Shape-estimation of human hand using polymer flex sensor and study of its application to control robot arm

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Hyuck; Kim, Dae Hyun [Seoul National University of Technology, Seoul (Korea, Republic of)

2015-02-15

Ultrasonic inspection robot systems have been widely researched and developed for the real-time monitoring of structures such as power plants. However, an inspection robot that is operated in a simple pattern has limitations in its application to various structures in a plant facility because of the diverse and complicated shapes of the inspection objects. Therefore, accurate control of the robot is required to inspect complicated objects with high-precision results. This paper presents the idea that the shape and movement information of an ultrasonic inspector's hand could be profitably utilized for the accurate control of robot. In this study, a polymer flex sensor was applied to monitor the shape of a human hand. This application was designed to intuitively control an ultrasonic inspection robot. The movement and shape of the hand were estimated by applying multiple sensors. Moreover, it was successfully shown that a test robot could be intuitively controlled based on the shape of a human hand estimated using polymer flex sensors.

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.

Kinematics of the human mandible for different head postures.

Science.gov (United States)

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

2000-04-01

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

The Relationship Between Postural and Movement Stability.

Science.gov (United States)

Feldman, Anatol G

2016-01-01

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

Postural changes in obese and non-obese children and adolescents. 10.5007/1980-0037.2011v13n6p448

Directory of Open Access Journals (Sweden)

Larissa Rosa da Silva

2011-11-01

Full Text Available Obesity has reached epidemic proportions over recent years and is related to cardiovascular risk factors, as well as to the occurrence of postural changes in adults, children and adolescents. The objective of this study was to identify the prevalence of postural abnormalities and pain in schoolchildren. Fifty-one children and adolescents of both genders aged 9-17 years were divided into an obese (n = 33 and a non-obese group (n = 18. Weight and height were measured to calculate the body mass index. A questionnaire was used to assess the presence or absence of pain. Postural deviations of the shoulder, head and knees were analyzed by photometry using the Corel Draw12 software for the determination of angular measures and size. Obese boys showed greater postural changes in the region of the knees than non-obese ones (p<0.001. No significant differences in any of the regions analyzed were observed for girls. On the other hand, the prevalence of pain was significantly higher among obese girls than among non-obese girls. We conclude that postural changes are not limited to obese children, but excess weight may increase this deviation. Further studies are needed to diagnose these changes during childhood in order to permit early intervention and good posture in adult life.

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.

Elderly individuals with increased risk of falls show postural balance impairment

Directory of Open Access Journals (Sweden)

Márcio Rogério de Oliveira

Full Text Available Introduction Falls are a serious public health problem. Objective The aim of this study was to evaluate whether elderly individuals with increased risk of falls have a postural balance deficit, evaluated using a force platform during a one-leg stance. Materials and methods The sample consisted of 94 physically independent elderly individuals from the EELO project. The instruments used were the Downton scale, in order to assess the risk as well as the history of falls, and the force platform to measure postural balance through parameters from the center of pressure (COP. Results Elderly individuals were split into two groups according to the score observed with the Downton scale: G1 — low fall risk (score ≤ 2 — and G2 — high fall risk (score > 2. No differences were observed between the groups concerning gender (P > 0.05, Chi Square test. On the other hand, individuals from G2 showed postural instability when compared to individuals from G1, and individuals from G2 showed higher values in all COP parameters analysed (Mann-Whitney test, P < 0.05. Conclusion It can be concluded that the Downton scale has sensitivity for identifying individuals with balance impairment as well as a risk of falls. Therefore, it may be suggested that this scale may be useful in primary health care for detecting falls in the elderly.

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

Science.gov (United States)

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

2016-01-01

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

Postural performance and strategy in the unipedal stance of soccer players at different levels of competition.

Science.gov (United States)

Paillard, Thierry; Noé, Frédéric; Rivière, Terence; Marion, Vincent; Montoya, Richard; Dupui, Philippe

2006-01-01

Sport training enhances the ability to use somatosensory and otolithic information, which improves postural capabilities. Postural changes are different according to the sport practiced, but few authors have analyzed subjects' postural performances to discriminate the expertise level among highly skilled athletes within a specific discipline. To compare the postural performance and the postural strategy between soccer players at different levels of competition (national and regional). Repeated measures with 1 between-groups factor (level of competition: national or regional) and 1 within-groups factor (vision: eyes open or eyes closed). Dependent variables were center-of-pressure surface area and velocity; total spectral energy; and percentage of low-, medium-, and high-frequency band. Sports performance laboratory. Fifteen national male soccer players (age = 24 +/- 3 years, height = 179 +/- 5 cm, mass = 72 +/- 3 kg) and 15 regional male soccer players (age = 23 +/- 3 years, height = 174 +/- 4 cm, mass = 68 +/- 5 kg) participated in the study. The subjects performed posturographic tests with eyes open and closed. While subjects performed static and dynamic posturographic tests, we measured the center of foot pressure on a force platform. Spatiotemporal center-of-pressure measurements were used to evaluate the postural performance, and a frequency analysis of the center-of-pressure excursions (fast Fourier transform) was conducted to estimate the postural strategy. Within a laboratory task, national soccer players produced better postural performances than regional players and had a different postural strategy. The national players were more stable than the regional players and used proprioception and vision information differently. In the test conditions specific to playing soccer, level of playing experience influenced postural control performance measures and strategies.

Bird-like anatomy, posture, and behavior revealed by an early jurassic theropod dinosaur resting trace

Science.gov (United States)

Milner, Andrew R.C.; Harris, J.D.; Lockley, M.G.; Kirkland, J.I.; Matthews, N.A.

2009-01-01

Background: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. Methodology/Principal Findings: Here we describe a well-preserved theropod trackway in a Lower Jurassic (???198 millionyear- old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. Conclusions/Significance: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods.

Bird-like anatomy, posture, and behavior revealed by an early jurassic theropod dinosaur resting trace.

Science.gov (United States)

Milner, Andrew R C; Harris, Jerald D; Lockley, Martin G; Kirkland, James I; Matthews, Neffra A

2009-01-01

Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 198 million-year-old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods.

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.

Modular finger and hand motion capturing system based on inertial and magnetic sensors

Directory of Open Access Journals (Sweden)

Valtin Markus

2017-03-01

Full Text Available The assessment of hand posture and kinematics is increasingly important in various fields. This includes the rehabilitation of stroke survivors with restricted hand function. This paper presents a modular, ambulatory measurement system for the assement of the remaining hand function and for closed-loop controlled therapy. The device is based on inertial sensors and utilizes up to five interchangeable sensor strips to achieve modularity and to simplify the sensor attachment. We introduce the modular hardware design and describe algorithms used to calculate the joint angles. Measurements with two experimental setups demonstrate the feasibility and the potential of such a tracking device.

Gait, posture and cognition in Parkinson's disease

OpenAIRE

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

2016-01-01

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

Postural ortostatisk takykardisyndrom

DEFF Research Database (Denmark)

Brinth, Louise; Pors, Kirsten; Mehlsen, Jesper

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Arun V. Subbarayalu, PhD

2017-12-01

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

Postural changes in obese and non-obese children and adolescents.DOI:10.5007/1980-0037.2011v13n6p448

Directory of Open Access Journals (Sweden)

Larissa Rosa da Silva

2011-11-01

Full Text Available Obesity has reached epidemic proportions over recent years and is related to cardiovascular risk factors, as well as to the occurrence of postural changes in adults, children and adolescents. The objective of this study was to identify the prevalence of postural abnormalities and pain in schoolchildren. Fifty-one children and adolescents of both genders aged 9-17 years were divided into an obese (n = 33 and a non-obese group (n = 18. Weight and height were measured to calculate the body mass index. A questionnaire was used to assess the presence or absence of pain. Postural deviations of the shoulder, head and knees were analyzed by photometry using the Corel Draw12 software for the determination of angular measures and size. Obese boys showed greater postural changes in the region of the knees than non-obese ones (p<0.001. No significant differences in any of the regions analyzed were observed for girls. On the other hand, the prevalence of pain was significantly higher among obese girls than among non-obese girls. We conclude that postural changes are not limited to obese children, but excess weight may increase this deviation. Further studies are needed to diagnose these changes during childhood in order to permit early intervention and good posture in adult life.

Thermoregulatory postures limit antipredator responses in peafowl

OpenAIRE

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

2018-01-01

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

Postural stability and occlusal status among Japanese elderly.

Science.gov (United States)

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

2012-06-01

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

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

Directory of Open Access Journals (Sweden)

Ya-Ling Teng

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

Peripheral, functional and postural asymmetries related to the preferred chewing side in adults with natural dentition.

Science.gov (United States)

Rovira-Lastra, B; Flores-Orozco, E I; Ayuso-Montero, R; Peraire, M; Martinez-Gomis, J

2016-04-01

The aim of this cross-sectional study was to determine the preferred chewing side and whether chewing side preference is related to peripheral, functional or postural lateral preferences. One hundred and forty-six adults with natural dentition performed three masticatory assays, each consisting of five trials of chewing three pieces of silicon placed into a latex bag for 20 cycles, either freestyle or unilaterally on the right- or left-hand side. Occlusal contact area in the intercuspal position, maximum bite force, masticatory performance and cycle duration were measured and the lateral asymmetry of these variables was calculated. Laterality tests were performed to determine handedness, footedness, earedness and eyedness as functional preferences, and hand-clasping, arm-folding and leg-crossing as postural lateral preferences. The preferred chewing side was determined using three different methods: assessment of the first chewing cycle for each trial, calculation of the asymmetry index from all cycles and application of a visual analogue scale. Bivariate relationship and multiple linear regression analyses were performed. Among unilateral chewers, 77% of them preferred the right side for chewing. The factors most closely related to the preferred chewing side were asymmetry of bite force, asymmetry of masticatory performance and earedness, which explained up to 16% of the variance. Although several functional or postural lateral preferences seem to be related to the preferred chewing side, peripheral factors such as asymmetry of bite force and of masticatory performance are the most closely related to the preferred chewing side in adults with natural dentition. © 2015 John Wiley & Sons Ltd.

BODY POSTURES AND ASYMMETRIES IN FRONTAL AND TRANSVERSE PLANES IN THE TRUNK AREA IN TABLE TENNIS PLAYERS

Directory of Open Access Journals (Sweden)

Katarzyna Barczyk-Pawelec

2012-04-01

Full Text Available The aim of this research was to assess the body posture within the trunk area in table tennis players and to estimate the correlations between the specific body posture types, their asymmetries and table tennis practice (training experience. To evaluate body posture the photogrammetric method based on the Moiré phenomenon with equipment by CQ Electronic was applied. Tests of significance of difference and correlation were used to estimate the correlation of the observed asymmetries with the training experience. 40 table tennis players and 43 subjects not practising sports participated in the research. The analysis of the results revealed that table tennis players, unlike non-players, are characterized by kyphotic body posture. It probably results from a specific trunk, head and limb position during table tennis matches. Thus, many asymmetries in frontal and transverse planes were observed in the examined table tennis players. Perhaps table tennis, which is characterized by intensive and one-sided trunk muscle work during its performance, is in favour of creating asymmetries. The majority of subjects did not reveal any statistically significant correlations between the observed body posture types, their asymmetries and training experience. However, it was observed that training experience is significantly related to the considerable asymmetry of the inclination angle of shoulder line (KLB. It may result from the negative influence of very intensive, one-sided work and constant work of the shoulder girdle muscles of the playing limb with negligence of exercises of the second limb.

Cinerama sickness and postural instability.

Science.gov (United States)

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

2013-01-01

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

The importance of postural cues for determining eye height in immersive virtual reality.

Science.gov (United States)

Leyrer, Markus; Linkenauger, Sally A; Bülthoff, Heinrich H; Mohler, Betty J

2015-01-01

In human perception, the ability to determine eye height is essential, because eye height is used to scale heights of objects, velocities, affordances and distances, all of which allow for successful environmental interaction. It is well understood that eye height is fundamental to determine many of these percepts. Yet, how eye height itself is provided is still largely unknown. While the information potentially specifying eye height in the real world is naturally coincident in an environment with a regular ground surface, these sources of information can be easily divergent in similar and common virtual reality scenarios. Thus, we conducted virtual reality experiments where we manipulated the virtual eye height in a distance perception task to investigate how eye height might be determined in such a scenario. We found that humans rely more on their postural cues for determining their eye height if there is a conflict between visual and postural information and little opportunity for perceptual-motor calibration is provided. This is demonstrated by the predictable variations in their distance estimates. Our results suggest that the eye height in such circumstances is informed by postural cues when estimating egocentric distances in virtual reality and consequently, does not depend on an internalized value for eye height.

The importance of postural cues for determining eye height in immersive virtual reality.

Directory of Open Access Journals (Sweden)

Markus Leyrer

Full Text Available In human perception, the ability to determine eye height is essential, because eye height is used to scale heights of objects, velocities, affordances and distances, all of which allow for successful environmental interaction. It is well understood that eye height is fundamental to determine many of these percepts. Yet, how eye height itself is provided is still largely unknown. While the information potentially specifying eye height in the real world is naturally coincident in an environment with a regular ground surface, these sources of information can be easily divergent in similar and common virtual reality scenarios. Thus, we conducted virtual reality experiments where we manipulated the virtual eye height in a distance perception task to investigate how eye height might be determined in such a scenario. We found that humans rely more on their postural cues for determining their eye height if there is a conflict between visual and postural information and little opportunity for perceptual-motor calibration is provided. This is demonstrated by the predictable variations in their distance estimates. Our results suggest that the eye height in such circumstances is informed by postural cues when estimating egocentric distances in virtual reality and consequently, does not depend on an internalized value for eye height.

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

Science.gov (United States)

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

2017-11-01

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

Postural adjustments are modulated by manual task complexity

Directory of Open Access Journals (Sweden)

Luis Augusto Teixeira

2009-09-01

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

Mental rotation of anthropoid hands: a chronometric study

Directory of Open Access Journals (Sweden)

L.G. Gawryszewski

2007-03-01

Full Text Available It has been shown that mental rotation of objects and human body parts is processed differently in the human brain. But what about body parts belonging to other primates? Does our brain process this information like any other object or does it instead maximize the structural similarities with our homologous body parts? We tried to answer this question by measuring the manual reaction time (MRT of human participants discriminating the handedness of drawings representing the hands of four anthropoid primates (orangutan, chimpanzee, gorilla, and human. Twenty-four right-handed volunteers (13 males and 11 females were instructed to judge the handedness of a hand drawing in palm view by pressing a left/right key. The orientation of hand drawings varied from 0º (fingers upwards to 90º lateral (fingers pointing away from the midline, 180º (fingers downwards and 90º medial (finger towards the midline. The results showed an effect of rotation angle (F(3, 69 = 19.57, P < 0.001, but not of hand identity, on MRTs. Moreover, for all hand drawings, a medial rotation elicited shorter MRTs than a lateral rotation (960 and 1169 ms, respectively, P < 0.05. This result has been previously observed for drawings of the human hand and related to biomechanical constraints of movement performance. Our findings indicate that anthropoid hands are essentially equivalent stimuli for handedness recognition. Since the task involves mentally simulating the posture and rotation of the hands, we wondered if "mirror neurons" could be involved in establishing the motor equivalence between the stimuli and the participants' own hands.

The effects of brief swaying on postural control.

Science.gov (United States)

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

2017-12-06

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

Development of posture-specific computational phantoms using motion capture technology and application to radiation dose-reconstruction for the 1999 Tokai-Mura nuclear criticality accident

International Nuclear Information System (INIS)

Vazquez, Justin A; Caracappa, Peter F; Xu, X George

2014-01-01

The majority of existing computational phantoms are designed to represent workers in typical standing anatomical postures with fixed arm and leg positions. However, workers found in accident-related scenarios often assume varied postures. This paper describes the development and application of two phantoms with adjusted postures specified by data acquired from a motion capture system to simulate unique human postures found in a 1999 criticality accident that took place at a JCO facility in Tokai-Mura, Japan. In the course of this accident, two workers were fatally exposed to extremely high levels of radiation. Implementation of the emergent techniques discussed produced more accurate and more detailed dose estimates for the two workers than were reported in previous studies. A total-body dose of 6.43 and 26.38 Gy was estimated for the two workers, who assumed a crouching and a standing posture, respectively. Additionally, organ-specific dose estimates were determined, including a 7.93 Gy dose to the thyroid and 6.11 Gy dose to the stomach for the crouching worker and a 41.71 Gy dose to the liver and a 37.26 Gy dose to the stomach for the standing worker. Implications for the medical prognosis of the workers are discussed, and the results of this study were found to correlate better with the patient outcome than previous estimates, suggesting potential future applications of such methods for improved epidemiological studies involving next-generation computational phantom tools. (paper)

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.

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

Science.gov (United States)

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

2017-07-01

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

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

Science.gov (United States)

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

2014-02-01

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

Bird-like anatomy, posture, and behavior revealed by an early jurassic theropod dinosaur resting trace.

Directory of Open Access Journals (Sweden)

Andrew R C Milner

Full Text Available BACKGROUND: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 198 million-year-old lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. CONCLUSIONS/SIGNIFICANCE: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods.

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.

Work postural analysis and musculoskeletal injury risk in critical working station at XYZ Ceramics Yogyakarta

Directory of Open Access Journals (Sweden)

Sari Amarria Dila

2018-01-01

Full Text Available Companies that have manual work, muscle injury is one of the major health issues that often occur when working. XYZ Ceramics Yogyakarta is still doing work activities involving manual processes and there has been identified that worker posture has the potential to cause injury. From the Nordic Body Map questionnaire, complaint was identified in the back were 88%, the knees were 80%, the upper arm 75%, and the right shoulder by 70% from 15 workers. The Ovako Work Posture Analysis System (OWAS method is used to evaluate and analyze work attitudes so that improved categories of work methods and recommendations could be obtained. Plan for Identifiering av Belastningsfaktorer (PLIBEL was used to identify the factors that cause muscle injury or harmful effect. In addition, the Nordic Body Map was applied to determine the critical work station. The purpose of this research is to analyze work posture and description of risk level related to musculoskeletal injury at critical work station. The three highest percentage of risk of muscle injury identified at raw material processing station, based on calculation result of PLIBEL Checklist, were on elbow, forearm, and hand. Based on the assessment of working posture using OWAS, the highest action category is identified in the activity of moving the cart containing the soil to the automatic pest that is the action category of 4, which means that this activity is very dangerous for the musculoskeletal system.

Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans

OpenAIRE

Silvani, Alessandro; Calandra-Buonaura, Giovanna; Johnson, Blair D.; van Helmond, Noud; Barletta, Giorgio; Cecere, Anna G.; Joyner, Michael J.; Cortelli, Pietro

2017-01-01

The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBR...

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

Directory of Open Access Journals (Sweden)

Fatih Celebi

2017-01-01

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

The effect of body postures on the distribution of air gap thickness and contact area.

Science.gov (United States)

Mert, Emel; Psikuta, Agnes; Bueno, Marie-Ange; Rossi, René M

2017-02-01

The heat and mass transfer in clothing is predominantly dependent on the thickness of air layer and the magnitude of contact area between the body and the garment. The air gap thickness and magnitude of the contact area can be affected by the posture of the human body. Therefore, in this study, the distribution of the air gap and the contact area were investigated for different body postures of a flexible manikin. In addition, the effect of the garment fit (regular and loose) and style (t-shirts, sweatpants, jacket and trousers) were analysed for the interaction between the body postures and the garment properties. A flexible manikin was scanned using a three-dimensional (3D) body scanning technique, and the scans were post-processed in dedicated software. The body posture had a strong effect on the air gap thickness and the contact area for regions where the garment had a certain distance from the body. Furthermore, a mathematical model was proposed to estimate the possible heat transfer coefficient for the observed air layers and their change with posture. The outcome of this study can be used to improve the design of the protective and functional garments and predict their effect on the human body.

Accessing hospital packaged foods and beverages: the importance of a seated posture when eating.

Science.gov (United States)

Bell, A; Tapsell, L; Walton, K; Yoxall, A

2017-06-01

Hospitalised and community dwelling older people (aged 65 years and over) have difficulties opening certain food and beverage items (e.g. cheese portions and tetra packs) served in public hospitals. Previously, the role of hand strength on successful pack opening has been explored in a seated position. However, because many people in hospital eat in bed, the present laboratory study examined the differences between participants opening a selection of products in a hospital bed and a chair. The present study used a qualitative method (satisfaction) and quantitative methods (grip and pinch strength, dexterity, time and attempts) in two conditions (bed; chair) in a sample of well older community dwelling adults (n = 34). Packs tested included foil sealed thickened pudding, foil sealed thickened water, tetra pack, dessert, custard, jam, cereal, honey sachet and cheese portions. Honey sachets, cheese portions, foil sealed thickened pudding and tetra packs were the most difficult packs to open, with 15% of cheese portions unable to be opened in either the bed or chair posture. Although grip strength was consistent for each posture, pinch grips and dexterity were adversely affected by the bed posture. Lying in a hospital bed required greater pinch strength and dexterity to open packs. Eating in a seated position when in hospital has been shown to improve intake. The present study demonstrates that eating in a seated posture is also advantageous for opening the food and beverage packs used in the NSW hospital food service and supports the notion that patients should sit to eat in hospital. © 2016 The British Dietetic Association Ltd.

The defence technique in Tai Chi Push Hands: a case study.

Science.gov (United States)

Chen, Hui-Chuan; Cheng, Kuang-You B; Liu, Yu-Jen; Chiu, Hung-Ta; Cheng, Kuang-Yu

2010-12-01

Developed from traditional Chinese martial arts, Tai Chi exercise includes different forms and interactive Push Hands but biomechanical analyses have focused on the former only. To analyse the techniques of Push Hands, an experienced master was asked to defend pushing by four opponents. Movements were videotaped and digitized using a motion analysis system. Surface electrodes were used to record the electromyographic activity of ten muscle groups. Two force plates were used to measure the ground reaction force on each foot. Inexperienced individuals performed the same procedure to serve as the control group. The results indicate that the master adopted a postural adjustment to maintain balance. A clear shift of body weight from the front to the rear foot and mediolateral displacement of the centre of gravity was observed. Low electromyographic activity was observed in the upper body muscle groups, while high electromyographic activity was observed in the right rectus femoris and very high activity in the left rectus femoris during the defence. All inexperienced participants lost their balance in resisting pushing. It is concluded that the Tai Chi defensive technique includes a subtle postural adjustment that slightly changes the pushing force direction, and allows the rear leg to resist the incoming force.

Assessing Somatosensory Utilization during Unipedal Postural Control.

Science.gov (United States)

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

2017-01-01

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

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

Science.gov (United States)

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

1989-01-01

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

Relationship between craniomandibular disorders and poor posture.

Science.gov (United States)

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

2000-04-01

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

The reliability and validity of the Saliba Postural Classification System.

Science.gov (United States)

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

2016-07-01

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

Estimation of stature from hand and handprint measurements in Iban population in Sarawak, Malaysia and its applications in forensic investigation.

Science.gov (United States)

Zulkifly, Nuranis-Raihan; Wahab, Roswanira Abd; Layang, Elizabeth; Ismail, Dzulkiflee; Desa, Wan Nur Syuhaila Mat; Hisham, Salina; Mahat, Naji A

2018-01-01

Handprints and dismembered hands are commonly found during crime scene investigations and disaster victim identifications, respectively. It has been indicated that the accuracy of handprint and hand measurements for estimating stature maybe population specific. Since Iban is the largest ethnic population in Sarawak, Malaysia and because the application of anthropometry of hand and handprint within this population as well as other populations within the Southeast Asian countries remain unreported, this present study that investigated the reliability and accuracy of these two anthropometric aspects acquires forensic significance. Upon measuring the height, 21 measurements were recorded on each hand and the corresponding handprint of 50 male and 52 female consented adult Iban subjects. Using univariate statistics as well as simple and multiple regression analyses, interpretation of the measurements examined here was attempted. Results revealed that lengths of hand and handprint are the more reliable traits for estimating stature in both the male and female Iban subjects (p Sarawak that may prove useful for crime scene investigations and disaster victim identifications in Malaysia. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Ergonomic strategies to improve radiographers' posture during mammography activities.

Science.gov (United States)

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

2017-08-01

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

Postural ortostatisk takykardi-syndrom

DEFF Research Database (Denmark)

Brinth, Louise; Pors, Kirsten; Mehlsen, Jesper

2015-01-01

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

Assessing Somatosensory Utilization during Unipedal Postural Control

OpenAIRE

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

2017-01-01

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

Postural Control in Children: Implications for Pediatric Practice

Science.gov (United States)

Westcott, Sarah L.; Burtner, Patricia

2004-01-01

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

Decrease in back strength in asymmetric trunk postures

NARCIS (Netherlands)

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

1992-01-01

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

Investigating the Effects of Different Working Postures on Cognitive Performance

Directory of Open Access Journals (Sweden)

Sharareh Mohammadi

2018-01-01

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

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

Science.gov (United States)

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

2012-10-01

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

Optical Enhancement of Exoskeleton-Based Estimation of Glenohumeral Angles

Science.gov (United States)

Cortés, Camilo; Unzueta, Luis; de los Reyes-Guzmán, Ana; Ruiz, Oscar E.; Flórez, Julián

2016-01-01

In Robot-Assisted Rehabilitation (RAR) the accurate estimation of the patient limb joint angles is critical for assessing therapy efficacy. In RAR, the use of classic motion capture systems (MOCAPs) (e.g., optical and electromagnetic) to estimate the Glenohumeral (GH) joint angles is hindered by the exoskeleton body, which causes occlusions and magnetic disturbances. Moreover, the exoskeleton posture does not accurately reflect limb posture, as their kinematic models differ. To address the said limitations in posture estimation, we propose installing the cameras of an optical marker-based MOCAP in the rehabilitation exoskeleton. Then, the GH joint angles are estimated by combining the estimated marker poses and exoskeleton Forward Kinematics. Such hybrid system prevents problems related to marker occlusions, reduced camera detection volume, and imprecise joint angle estimation due to the kinematic mismatch of the patient and exoskeleton models. This paper presents the formulation, simulation, and accuracy quantification of the proposed method with simulated human movements. In addition, a sensitivity analysis of the method accuracy to marker position estimation errors, due to system calibration errors and marker drifts, has been carried out. The results show that, even with significant errors in the marker position estimation, method accuracy is adequate for RAR. PMID:27403044

Voluntarily controlled but not merely observed visual feedback affects postural sway

Science.gov (United States)

Asai, Tomohisa; Hiromitsu, Kentaro; Imamizu, Hiroshi

2018-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

Meyers, Ron A

1997-07-01

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

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

OpenAIRE

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

2015-01-01

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

PENINGKATAN STABILITAS POSTURAL PADA LANSIA MELALUI BALANCE EXERCISE

Directory of Open Access Journals (Sweden)

Kusnanto .

2010-12-01

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

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

Directory of Open Access Journals (Sweden)

Anna Sagan

2018-02-01

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

Hand Gesture Recognition Using Ultrasonic Waves

KAUST Repository

AlSharif, Mohammed Hussain

2016-01-01

estimation of the moving hand and received signal strength (RSS). These two factors are estimated using two simple methods; channel impulse response (CIR) and cross correlation (CC) of the reflected ultrasonic signal from the gesturing hand. A customized

Measurement of hemodynamics during postural changes using a new wearable cephalic laser blood flowmeter.

Science.gov (United States)

Fujikawa, Tetsuya; Tochikubo, Osamu; Kura, Naoki; Kiyokura, Takanori; Shimada, Junichi; Umemura, Satoshi

2009-10-01

Patients with orthostatic hypotension have pathologic hemodynamics related to changes in body posture. A new cephalic laser blood flowmeter that can be worn on the tragus to investigate the hemodynamics upon rising from a sitting or squatting posture was developed. The relationship between cephalic hemodynamics and cerebral ischemic symptoms in 63 subjects in a sitting, squatting, and standing positions using the new device was evaluated. Transient decrease in blood pressure within 15 s after rising to an erect position possibly causes dizziness, syncope, and fall. Subjects exhibiting dizziness upon standing showed a significant decrease in the cephalic blood flow (CBF) and indirect beat-to-beat systolic blood pressure, as monitored by the Finometer, and a significant correlation was observed between the drop ratio (drop value on rising/mean value in the squatting position) of CBF and that of systolic blood pressure. This new wearable CBF-meter is potentially useful for estimating cephalic hemodynamics and objectively diagnosing cerebral ischemic symptoms of subjects in a standing posture.

Postural balance in low back pain patients

DEFF Research Database (Denmark)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Satoko Ninomiya

2015-01-01

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

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

Science.gov (United States)

Fukunaga, Tsukasa; Iwasaki, Wataru

2017-01-19

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

Effect of Body Mass Index on Postural Balance and Muscle Strength in Children Aged 8-10 years

Directory of Open Access Journals (Sweden)

Lucky Prasetiowati

2017-04-01

Full Text Available Background:Childhood overweight and obesity, which are considered as global epidemic, can be assessed using Body Mass Index (BMI. BMI difference can lead to anatomic changes due to an increased body load. This increase might also affect motor performance, including changes in postural balance and muscle strength. Aims and Objectives: to explain the influence of BMI on postural balance and lower limb muscle strength and to assess the correlation between those two variables in children aged 8-10 years. Material and methods:The sample consisted of 63 children aged 8-10 years, which were divided in 3 groups: BMI-normal, BMI-overweight, and BMI-obese. The postural balance was assessed using single leg balance test on MatScan and the Center Of Pressure (COP area was recorded. Isometric muscle strength of hip extensor and knee extensor were measured using a hand-held dynamometer. Results: Obese children had significantly largerCOP area than overweight (p = 0.004 and normal weight children (p = 0.000.There were no significant differences in hip extensor muscle strength between obese children with overweight and normal weight children (p=0.527. The absolute knee extensor muscle strength in obese group was significantly higher than the overweight and normal group (p = 0.003. However the relative muscle strength of lower limb for obese children was significantly lower than for normal weight. There was no significant correlation between absolute hip extensor and knee extensor muscles strength with COP area. Conclusion: Obese children have decreased postural balance and increased absolute knee extensormuscle strength significantly when compared to overweight and normal children. There is no significant correlation between postural balance and muscle strength.

Posture does not matter! Paw usage and grasping paw preference in a small-bodied rooting quadrupedal mammal.

Science.gov (United States)

Joly, Marine; Scheumann, Marina; Zimmermann, Elke

2012-01-01

Recent results in birds, marsupials, rodents and nonhuman primates suggest that phylogeny and ecological factors such as body size, diet and postural habit of a species influence limb usage and the direction and strength of limb laterality. To examine to which extent these findings can be generalised to small-bodied rooting quadrupedal mammals, we studied trees shrews (Tupaia belangeri). We established a behavioural test battery for examining paw usage comparable to small-bodied primates and tested 36 Tupaia belangeri. We studied paw usage in a natural foraging situation (simple food grasping task) and measured the influence of varying postural demands (triped, biped, cling, sit) on paw preferences by applying a forced-food grasping task similar to other small-bodied primates. Our findings suggest that rooting tree shrews prefer mouth over paw usage to catch food in a natural foraging situation. Moreover, we demonstrated that despite differences in postural demand, tree shrews show a strong and consistent individual paw preference for grasping across different tasks, but no paw preference at a population level. Tree shrews showed less paw usage than small-bodied quadrupedal and arboreal primates, but the same paw preference. Our results confirm that individual paw preferences remain constant irrespective of postural demand in some small-bodied quadrupedal non primate and primate mammals which do not require fine motoric control for manipulating food items. Our findings suggest that the lack of paw/hand preference for grasping food at a population level is a universal pattern among those species and that the influence of postural demand on manual lateralisation in quadrupeds may have evolved in large-bodied species specialised in fine manipulations of food items.

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

Kinect Posture Reconstruction Based on a Local Mixture of Gaussian Process Models.

Science.gov (United States)

Liu, Zhiguang; Zhou, Liuyang; Leung, Howard; Shum, Hubert P H

2016-11-01

Depth sensor based 3D human motion estimation hardware such as Kinect has made interactive applications more popular recently. However, it is still challenging to accurately recognize postures from a single depth camera due to the inherently noisy data derived from depth images and self-occluding action performed by the user. In this paper, we propose a new real-time probabilistic framework to enhance the accuracy of live captured postures that belong to one of the action classes in the database. We adopt the Gaussian Process model as a prior to leverage the position data obtained from Kinect and marker-based motion capture system. We also incorporate a temporal consistency term into the optimization framework to constrain the velocity variations between successive frames. To ensure that the reconstructed posture resembles the accurate parts of the observed posture, we embed a set of joint reliability measurements into the optimization framework. A major drawback of Gaussian Process is its cubic learning complexity when dealing with a large database due to the inverse of a covariance matrix. To solve the problem, we propose a new method based on a local mixture of Gaussian Processes, in which Gaussian Processes are defined in local regions of the state space. Due to the significantly decreased sample size in each local Gaussian Process, the learning time is greatly reduced. At the same time, the prediction speed is enhanced as the weighted mean prediction for a given sample is determined by the nearby local models only. Our system also allows incrementally updating a specific local Gaussian Process in real time, which enhances the likelihood of adapting to run-time postures that are different from those in the database. Experimental results demonstrate that our system can generate high quality postures even under severe self-occlusion situations, which is beneficial for real-time applications such as motion-based gaming and sport training.

Postural steadiness and ankle force variability in peripheral neuropathy

Science.gov (United States)

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

2015-01-01

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

Postural Stabilization Differences in Idiopathic Parkinson’s Disease and Progressive Supranuclear Palsy during Self-Triggered Fast Forward Weight Lifting

Directory of Open Access Journals (Sweden)

Stefan Kammermeier

2018-01-01

Full Text Available Progressive supranuclear palsy (PSP and late-stage idiopathic Parkinson’s disease (IPD are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Self-triggered, weighted movements appear to provoke falls in IPD, but not in PSP. Repeated self-triggered lifting of a 0.5–1-kg weight (<2% of body weight with the dominant hand was performed in 17 PSP, 15 IPD with falling history, and 16 controls on a posturography platform. PSP showed excessive force scaling of weight and body motion with high-frequency multiaxial body sway, whereas IPD presented a delayed-onset forward body displacement. Differences in center of mass displacement apparent at very small weights indicate that both syndromes decompensate postural control already within stability limits. PSP may be subject to specific postural system devolution. IPD are susceptible to delayed forward falling. Differential physiotherapy strategies are suggested.

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.

Postural Response Signal Characteristics Identified by Method of Developed Statokinesigram

Directory of Open Access Journals (Sweden)

Barbolyas Boris

2015-12-01

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

Olecranon orientation as an indicator of elbow joint angle in the stance phase, and estimation of forelimb posture in extinct quadruped animals.

Science.gov (United States)

Fujiwara, Shin-Ichi

2009-09-01

Reconstruction of limb posture is a challenging task in assessing functional morphology and biomechanics of extinct tetrapods, mainly because of the wide range of motions possible at each limb joint and because of our poor knowledge of the relationship between posture and musculoskeletal structure, even in the extant taxa. This is especially true for extinct mammals such as the desmostylian taxa Desmostylus and Paleoparadoxia. This study presents a procedure that how the elbow joint angles of extinct quadruped mammals can be inferred from osteological characteristics. A survey of 67 dried skeletons and 113 step cycles of 32 extant genera, representing 25 families and 13 orders, showed that the olecranon of the ulna and the shaft of the humerus were oriented approximately perpendicular to each other during the stance phase. At this angle, the major extensor muscles maximize their torque at the elbow joint. Based on this survey, I suggest that olecranon orientation can be used for inferring the elbow joint angles of quadruped mammals with prominent olecranons, regardless of taxon, body size, and locomotor guild. By estimating the elbow joint angle, it is inferred that Desmostylus would have had more upright forelimbs than Paleoparadoxia, because their elbow joint angles during the stance phase were approximately 165 degrees and 130 degrees , respectively. Difference in elbow joint angles between these two genera suggests possible differences in stance and gait of these two mammals. Copyright 2009 Wiley-Liss, Inc.

Head movements and postures as pain behavior

Science.gov (United States)

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

2018-01-01

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

Perceiving Conspecifics is Not Purely Visual: “Body Gestalt” Completion is Influenced by the Body Posture of the Observer

Directory of Open Access Journals (Sweden)

K Kessler

2011-04-01

Full Text Available When we perceive other people in our everyday encounters their bodies are often partially occluded. High-level visual areas are known to automatically complete partially occluded objects, as revealed by the classic “gestalt” phenomena. However, here we set out to investigate if “body gestalt” completion is “embodied” and not purely visual. Human observers might intuitively map their own body knowledge onto partially occluded others and thereby complete their “body gestalt” by means of posture and/or motor resonance. To this end we developed new stimuli showing a face and two hands that could either form a “body gestalt” or not. Our most important finding across five behavioural experiments was that body gestalt completion was not solely based on visual features like the classic gestalt phenomena. Responses were significantly faster when the observer's posture matched the configuration of face and hands shown on screen then. In this sense body gestalt completion is an embodied process, where humans intuitively use their own body knowledge to ‘fill in the gaps’ in a body stimulus. We further conclude that in our particular paradigm posture resonance was apparently more important for body gestalt completion than motor resonance—with the former being most likely mediated by proprioceptive body schema representations, while the latter by the mirror neuron system. Finally, we will also present preliminary analysis of MEG data. Our findings elucidate the mechanisms of how humans perceive others holistically and how they might implicitly align themselves in everyday social interactions to facilitate an optimal co-representation of each other.

Studies on the Estimation of Stature from Hand and Foot Length of an Individual

Directory of Open Access Journals (Sweden)

O. S. Saka

2016-10-01

Full Text Available Background: Studies on the estimation of stature from hand and foot length of an individual are essential study in personal identification. Aim and Objectives: This study is to find out correlation between statures with hand and foot dimensions in both sexes and gender comparison from an individual in Lautech Staff College in Ogbomoso and College ogbomoso and College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria. Material and Methods: A sample of 140 students and staff; 70 male and 70 female Students and staff of Lautech Staff College in Ogbomoso and College ogbomoso and College of Health Sciences, Obafemi Awolowo University, Ile-Ife, between 16-35years were considered and measurements were taken for each of the parameters. Gender differences for the two parameters were determined using Student t-test. Pearson's correlation coefficient (r was used to examine the relationship between two anthropometric parameters and standing height (stature. All these measurements were done by using standard anthropometric instruments and standard anthropometric techniques. Results: The findings of the study indicated that the males mean values are not significantly difference when compared with females mean values in all measured parameters. The study showed significant (p<0.001 positive correlation between the stature with hand lengths and foot lengths. The hand and foot length provide accurate and reliable means in establishing the height of an individual. Conclusion: This study will be useful for forensic scientists and anthropologists as well as anatomists in ascertain medico-legal cases

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

Science.gov (United States)

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

2016-04-01

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

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

African Journals Online (AJOL)

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

Association between temporomandibular disorders and abnormal head postures

Directory of Open Access Journals (Sweden)

Evandro Francisco FAULIN

2015-01-01

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

Relationship between static foot posture and foot mobility

Directory of Open Access Journals (Sweden)

McPoil Thomas G

2011-01-01

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

Estimation of hand hygiene opportunities on an adult medical ward using 24-hour camera surveillance: validation of the HOW2 Benchmark Study.

Science.gov (United States)

Diller, Thomas; Kelly, J William; Blackhurst, Dawn; Steed, Connie; Boeker, Sue; McElveen, Danielle C

2014-06-01

We previously published a formula to estimate the number of hand hygiene opportunities (HHOs) per patient-day using the World Health Organization's "Five Moments for Hand Hygiene" methodology (HOW2 Benchmark Study). HHOs can be used as a denominator for calculating hand hygiene compliance rates when product utilization data are available. This study validates the previously derived HHO estimate using 24-hour video surveillance of health care worker hand hygiene activity. The validation study utilized 24-hour video surveillance recordings of 26 patients' hospital stays to measure the actual number of HHOs per patient-day on a medicine ward in a large teaching hospital. Statistical methods were used to compare these results to those obtained by episodic observation of patient activity in the original derivation study. Total hours of data collection were 81.3 and 1,510.8, resulting in 1,740 and 4,522 HHOs in the derivation and validation studies, respectively. Comparisons of the mean and median HHOs per 24-hour period did not differ significantly. HHOs were 71.6 (95% confidence interval: 64.9-78.3) and 73.9 (95% confidence interval: 69.1-84.1), respectively. This study validates the HOW2 Benchmark Study and confirms that expected numbers of HHOs can be estimated from the unit's patient census and patient-to-nurse ratio. These data can be used as denominators in calculations of hand hygiene compliance rates from electronic monitoring using the "Five Moments for Hand Hygiene" methodology. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Characterization of postural control impairment in women with fibromyalgia

Science.gov (United States)

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

2018-01-01

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

Relationships between craniocervical posture and pain-related disability in patients with cervico-craniofacial pain

Science.gov (United States)

López-de-Uralde-Villanueva, Ibai; Beltran-Alacreu, Hector; Paris-Alemany, Alba; Angulo-Díaz-Parreño, Santiago; La Touche, Roy

2015-01-01

Objectives This cross-sectional correlation study explored the relationships between craniocervical posture and pain-related disability in patients with chronic cervico-craniofacial pain (CCFP). Moreover, we investigated the test–retest intrarater reliability of two craniocervical posture measurements: head posture (HP) and the sternomental distance (SMD). Methods Fifty-three asymptomatic subjects and 60 CCFP patients were recruited. One rater measured HP and the SMD using a cervical range of motion device and a digital caliper, respectively. The Spanish versions of the neck disability index and the craniofacial pain and disability inventory were used to assess pain-related disability (neck disability and craniofacial disability, respectively). Results We found no statistically significant correlations between craniocervical posture and pain-related disability variables (HP and neck disability [r=0.105; P>0.05]; HP and craniofacial disability [r=0.132; P>0.05]; SMD and neck disability [r=0.126; P>0.05]; SMD and craniofacial disability [r=0.195; P>0.05]). A moderate positive correlation was observed between HP and SMD for both groups (asymptomatic subjects, r=0.447; CCFP patients, r=0.52). Neck disability was strongly positively correlated with craniofacial disability (r=0.79; Pposture, but these differences were very small (mean difference =1.44 cm for HP; 6.24 mm for SMD). The effect sizes reached by these values were estimated to be small for SMD (d=0.38) and medium for HP (d=0.76). Conclusion The results showed no statistically significant correlations between craniocervical posture and variables of pain-related disability, but a strong correlation between the two variables of disability was found. Our findings suggest that small differences between CCFP patients and asymptomatic subjects exist with respect to the two measurements used to assess craniocervical posture (HP and SMD), and these measures demonstrated high test–retest intrarater reliability for

Research of a New 6-Dof Force Feedback Hand Controller System

Directory of Open Access Journals (Sweden)

Xin Gao

2014-01-01

Full Text Available The field of teleoperation with force telepresence has expanded its scope to include manipulation at different scales and in virtual worlds, and the key component of which is force feedback hand controller. This paper presents a novel force feedback hand controller system, including a 3-dof translational and 3-dof rotational hand controllers, respectively, to implement position and posture teleoperation of the robot end effector. The 3-dof translational hand controller adopts innovative three-axes decoupling structure based on the linear motor; the 3-dof rotational hand controller adopts serial mechanism based on three-axes intersecting at one point, improving its overall stiffness. Based on the kinematics, statics, and dynamics analyses for two platforms separately, the system applies big closed-loop force control method based on the zero force/torque, improving the feedback force/torque accuracy effectively. Experimental results show that self-developed 6-dof force feedback hand controller has good mechanical properties. The translational hand controller has the following advantages: simple kinematics solver, fast dynamic response, and better than 0.05 mm accuracy of three-axis end positioning, while the advantages of the rotational hand controller are wide turning space, larger than 1 Nm feedback, greater than 180 degrees of operating space of three axes, respectively, and high operation precision.

Influence of pain on postural control in women with neck pain

Directory of Open Access Journals (Sweden)

Juliana Soares

2013-04-01

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

Postural Variables in Girls Practicing Volleyball

Science.gov (United States)

Grabara, Malgorzata; Hadzik, Andrzej

2009-01-01

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

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

Science.gov (United States)

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

1992-01-01

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

Barnacle geese achieve significant energetic savings by changing posture.

Science.gov (United States)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Zoran Bogdanović

2007-05-01

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

Effects of posture on postoperative pulmonary function

DEFF Research Database (Denmark)

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

2003-01-01

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

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

African Journals Online (AJOL)

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

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…

Cerebellar transcranial direct current stimulation improves adaptive postural control.

Science.gov (United States)

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

2018-01-01

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

Arterial Pressure Gradients during Upright Posture and 30 deg Head Down Tilt

Science.gov (United States)

Sanchez, E. R; William, J. M.; Ueno, T.; Ballard, R. E.; Hargens, A. R.; Holton, Emily M. (Technical Monitor)

1997-01-01

Gravity alters local blood pressure within the body so that arterial pressures in the head and foot are lower and higher, respectively, than that at heart level. Furthermore, vascular responses to local alterations of arterial pressure are probably important to maintain orthostatic tolerance upon return to the Earth after space flight. However, it has been difficult to evaluate the body's arterial pressure gradient due to the lack of noninvasive technology. This study was therefore designed to investigate whether finger arterial pressure (FAP), measured noninvasively, follows a normal hydrostatic pressure gradient above and below heart level during upright posture and 30 deg head down tilt (HDT). Seven healthy subjects gave informed consent and were 19 to 52 years old with a height range of 158 to 181 cm. A Finapres device measured arterial pressure at different levels of the body by moving the hand from 36 cm below heart level (BH) to 72 cm above heart level (AH) in upright posture and from 36 cm BH to 48 cm AH during HDT in increments of 12 cm. Mean FAP creased by 85 mmHg transitioning from BH to AH in upright posture, and the pressure gradient calculated from hydrostatic pressure difference (rho(gh)) was 84 mmHg. In HDT, mean FAP decreased by 65 mmHg from BH to AH, and the calculated pressure gradient was also 65 mmHg. There was no significant difference between the measured FAP gradient and the calculated pressure gradient, although a significant (p = 0.023) offset was seen for absolute arterial pressure in upright posture. These results indicate that arterial pressure at various levels can be obtained from the blood pressure at heart level by calculating rho(gh) + an offset. The offset equals the difference between heart level and the site of measurement. In summary, we conclude that local blood pressure gradients can be measured by noninvasive studies of FAP.

Posture does not matter! Paw usage and grasping paw preference in a small-bodied rooting quadrupedal mammal.

Directory of Open Access Journals (Sweden)

Marine Joly

Full Text Available BACKGROUND: Recent results in birds, marsupials, rodents and nonhuman primates suggest that phylogeny and ecological factors such as body size, diet and postural habit of a species influence limb usage and the direction and strength of limb laterality. To examine to which extent these findings can be generalised to small-bodied rooting quadrupedal mammals, we studied trees shrews (Tupaia belangeri. METHODOLOGY/PRINCIPAL FINDINGS: We established a behavioural test battery for examining paw usage comparable to small-bodied primates and tested 36 Tupaia belangeri. We studied paw usage in a natural foraging situation (simple food grasping task and measured the influence of varying postural demands (triped, biped, cling, sit on paw preferences by applying a forced-food grasping task similar to other small-bodied primates. Our findings suggest that rooting tree shrews prefer mouth over paw usage to catch food in a natural foraging situation. Moreover, we demonstrated that despite differences in postural demand, tree shrews show a strong and consistent individual paw preference for grasping across different tasks, but no paw preference at a population level. CONCLUSIONS/SIGNIFICANCE: Tree shrews showed less paw usage than small-bodied quadrupedal and arboreal primates, but the same paw preference. Our results confirm that individual paw preferences remain constant irrespective of postural demand in some small-bodied quadrupedal non primate and primate mammals which do not require fine motoric control for manipulating food items. Our findings suggest that the lack of paw/hand preference for grasping food at a population level is a universal pattern among those species and that the influence of postural demand on manual lateralisation in quadrupeds may have evolved in large-bodied species specialised in fine manipulations of food items.

TabletGaze: Unconstrained Appearance-based Gaze Estimation in Mobile Tablets

OpenAIRE

Huang, Qiong; Veeraraghavan, Ashok; Sabharwal, Ashutosh

2015-01-01

We study gaze estimation on tablets, our key design goal is uncalibrated gaze estimation using the front-facing camera during natural use of tablets, where the posture and method of holding the tablet is not constrained. We collected the first large unconstrained gaze dataset of tablet users, labeled Rice TabletGaze dataset. The dataset consists of 51 subjects, each with 4 different postures and 35 gaze locations. Subjects vary in race, gender and in their need for prescription glasses, all o...

Relative importance of expertise, lifting height and weight lifted on posture and lumbar external loading during a transfer task in manual material handling.

Science.gov (United States)

Plamondon, André; Larivière, Christian; Delisle, Alain; Denis, Denys; Gagnon, Denis

2012-01-01

The objective of this study was to measure the effect size of three important factors in manual material handling, namely expertise, lifting height and weight lifted. The effect of expertise was evaluated by contrasting 15 expert and 15 novice handlers, the effect of the weight lifted with a 15-kg box and a 23-kg box and the effect of lifting height with two different box heights: ground level and a 32 cm height. The task consisted of transferring a series of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables (moments) while expertise had low impact. On the other hand, expertise showed a significant effect of posture variables on the lumbar spine and knees. All three factors are important, but for a reduction of external back loading, the focus should be on the lifting height and weight lifted. The objective was to measure the effect size of three important factors in a transfer of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables but expertise was a major determinant in back posture.

Efficacy and Effectiveness of Physical Therapy in Enhancing Postural Control in Children With Cerebral Palsy

Directory of Open Access Journals (Sweden)

Susan R. Harris

2005-01-01

Full Text Available The purpose of this article was to conduct a systematic review of studies that examined the efficacy and effectiveness of postural control intervention strategies for children with CP. Only physical therapy interventions were included, e.g. adaptive seating devices, ankle foot orthoses, neurodevelopmental treatment. A multifaceted search strategy was employed to identify all potential studies published between 1990 and 2004. The search strategy included electronic databases, reference list scanning, author and citation tracking of relevant studies, and hand searching of pediatric physical therapy journals and conference proceedings. Twelve studies (1991–2004, comprising ten group design studies and two single subject studies, met our inclusion criteria. A variety of age ranges and severity of children with cerebral palsy (n = 132 participated in the studies. The study quality scores ranged from 2 to 7 (total possible range of 0 to 7 with a median score of 5.5 and a mode of 6. As was true in an earlier systematic review on adaptive seating, most of the 12 ‘experimental’ studies published since 1990 that were aimed at evaluating the effectiveness of postural control strategies provided lower levels of evidence, i.e. Sackett Levels III to V. Additional studies with stronger designs are needed to establish that postural control interventions for children with CP are effective.

Postural habits of young adults and possibilities of modification.

Science.gov (United States)

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

2013-01-01

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

Postural stability in young and old women

DEFF Research Database (Denmark)

Jørgensen, Martin Grønbech

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

Postural effects when cycling in late pregnancy.

Science.gov (United States)

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

2006-12-01

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

Classifying Transition Behaviour in Postural Activity Monitoring

Directory of Open Access Journals (Sweden)

James BRUSEY

2009-10-01

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

Barnacle geese achieve significant energetic savings by changing posture.

Directory of Open Access Journals (Sweden)

Peter G Tickle

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

Estimation of pulmonary hypertension by perfusion lung scintigraphy: Gravitational effect of postural changes between the lateral decubitus positions

International Nuclear Information System (INIS)

Tanaka, Masao; Fujii, Tadashige; Hirayama, Jiro; Okubo, Shinichi; Sekiguchi, Morie

1990-01-01

To estimate pulmonary hypertension in patients with various heart diseases, we devised a new method using perfusion lung scintigraphy with 99m Tc-labelled macroaggregated albumin. In this method, changes in the distribution of pulmonary perfusion caused by gravitational effects, namely, changes in the total count ratios of the right lung against the left lung between right and left lateral decubitus positions (rt/lt), were assessed in 62 patients and in 10 normal subjects. The rt/lt ratios were calculated as indices of the above changes. They correlated significantly with mean pulmonary arterial pressure (mPAP) (γ=-0.62, P<0.001), pulmonary capillary wedge pressure (γ=-0.63, P<0.001) and pulmonary arteriolar resistance (γ=0.50, P<0.001) in all subjects. In 17 patients with valvular heart diseases, the ratio correlated significantly with mPAP (γ=-0.84, P<0.001). In 10 patients with various heart diseases, the U/S ratio, i.e. the index of changes in the count ratios of the upper field against the lower field for the right lung following postural change from the uprigth to the supine position, was also obtained as well as the rt/lt ratio. The latter evidenced a better correlation with mPAP (γ=-0.90, P<0.001) than the former (γ=-0.64, P<0.05). We conclude that this method is valuable as a noninvasive approach for the estimation of pulmonary hypertension. (orig.)

The relationship between the stomatognathic system and body posture

Directory of Open Access Journals (Sweden)

Antonino Cuccia

2009-01-01

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

The Relationship Between the Stomatognathic System and Body Posture

Science.gov (United States)

Cuccia, Antonino; Caradonna, Carola

2009-01-01

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

Otolith and Vertical Canal Contributions to Dynamic Postural Control

Science.gov (United States)

Black, F. Owen

1999-01-01

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

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

Science.gov (United States)

Kee, Dohyung; Karwowski, Waldemar

2007-01-01

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

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

Science.gov (United States)

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

2018-06-01

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

Effects of posture on FDTD calculations of specific absorption rate in a voxel model of the human body

Energy Technology Data Exchange (ETDEWEB)

Findlay, R P; Dimbylow, P J [National Radiological Protection Board, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom)

2005-08-21

A change in the posture of the human body can significantly affect the way in which it absorbs radiofrequency electromagnetic radiation. To study this, an anatomically realistic model of the body has been modified to develop new voxel models in postures other than the standard standing position with arms to the side. These postures were sitting, arms stretched out horizontally to the side and vertically above the head. Finite-difference time-domain (FDTD) calculations of the whole-body averaged specific energy absorption rate (SAR) have been performed from 10 MHz to 300 MHz at a resolution of 4 mm. Calculations show that the effect of a raised arm above the head posture was to increase the value of the whole-body averaged SAR at resonance by up to 35% when compared to the standard, arms by the side position. SAR values, both whole-body averaged and localized in the ankle, were used to derive the external electric field values required to produce the SAR basic restrictions of the ICNIRP guidelines. It was found that, in certain postures, external electric field reference levels alone would not provide a conservative estimate of localized SAR exposure and it would be necessary to invoke secondary reference levels on limb currents to provide compliance with restrictions.

Effects of posture on FDTD calculations of specific absorption rate in a voxel model of the human body

International Nuclear Information System (INIS)

Findlay, R P; Dimbylow, P J

2005-01-01

A change in the posture of the human body can significantly affect the way in which it absorbs radiofrequency electromagnetic radiation. To study this, an anatomically realistic model of the body has been modified to develop new voxel models in postures other than the standard standing position with arms to the side. These postures were sitting, arms stretched out horizontally to the side and vertically above the head. Finite-difference time-domain (FDTD) calculations of the whole-body averaged specific energy absorption rate (SAR) have been performed from 10 MHz to 300 MHz at a resolution of 4 mm. Calculations show that the effect of a raised arm above the head posture was to increase the value of the whole-body averaged SAR at resonance by up to 35% when compared to the standard, arms by the side position. SAR values, both whole-body averaged and localized in the ankle, were used to derive the external electric field values required to produce the SAR basic restrictions of the ICNIRP guidelines. It was found that, in certain postures, external electric field reference levels alone would not provide a conservative estimate of localized SAR exposure and it would be necessary to invoke secondary reference levels on limb currents to provide compliance with restrictions

Effects of posture on FDTD calculations of specific absorption rate in a voxel model of the human body

Science.gov (United States)

Findlay, R. P.; Dimbylow, P. J.

2005-08-01

A change in the posture of the human body can significantly affect the way in which it absorbs radiofrequency electromagnetic radiation. To study this, an anatomically realistic model of the body has been modified to develop new voxel models in postures other than the standard standing position with arms to the side. These postures were sitting, arms stretched out horizontally to the side and vertically above the head. Finite-difference time-domain (FDTD) calculations of the whole-body averaged specific energy absorption rate (SAR) have been performed from 10 MHz to 300 MHz at a resolution of 4 mm. Calculations show that the effect of a raised arm above the head posture was to increase the value of the whole-body averaged SAR at resonance by up to 35% when compared to the standard, arms by the side position. SAR values, both whole-body averaged and localized in the ankle, were used to derive the external electric field values required to produce the SAR basic restrictions of the ICNIRP guidelines. It was found that, in certain postures, external electric field reference levels alone would not provide a conservative estimate of localized SAR exposure and it would be necessary to invoke secondary reference levels on limb currents to provide compliance with restrictions.

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

Science.gov (United States)

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

2014-07-01

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

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

Science.gov (United States)

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

1999-11-01

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

Prediction of postural risk of fall initiation based on a two-variable description of body dynamics: position and velocity of center of mass.

Science.gov (United States)

Honarvar, Mohammad Hadi; Nakashima, Motomu

2013-10-01

This research addresses the question: what is the risk of fall initiation at a certain human posture? There are postures from which no one is able to keep their balance and a fall will surely initiate (risk=1), and others from which everyone may regain their stability (risk=0). In other postures, only a portion of people can control their stability. One may interpret risk to chance of a fall to be initiated, and based on the portion of fallers assign a risk value to a given human posture (postural risk). Human posture can be mapped to a point in a 2-dimensional space: the x-v plane, the axes of which are horizontal components of the position and velocity of the center of mass of the body. For every pair of (x, v), the outcome of the balance recovery problem defines whether a person with a given strength level is able to regain their stability when released from a posture corresponding to that point. Using strength distribution data, we estimated the portion of the population who will initiate a fall if starting at a certain posture. A fast calculation approach is also introduced to replace the time-consuming method of solving the recovery problem many times. Postural risk of fall initiation for situations expressed by (x, v) pairs for the entire x-v plane is calculated and shown in a color-map. Copyright © 2013 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

Lane, John R

2014-01-01

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

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

Science.gov (United States)

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

2007-10-01

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

Development of a method to assess compliance with ergonomic posture in dental students

Science.gov (United States)

Garcia, Patrícia Petromilli Nordi Sasso; Wajngarten, Danielle; Campos, Juliana Alvares Duarte Bonini

2018-01-01

CONTEXT: The ergonomic posture protocol is extremely important for the maintenance of occupational health in dentistry. The lack of compliance with this protocol results in a high risk of developing musculoskeletal disorders. AIMS: This study developed a direct observation method for the evaluation of dental student compliance with ergonomic posture protocol. SUBJECTS AND METHODS: The method is named compliance assessment of dental ergonomic posture requirements (CADEP). During the development of the method, 14 items were elaborated considering the theory of dental ergonomics. Each item should be classified as appropriate, partially appropriate, or inappropriate. After evaluation, all item values should be added, and the final score expressed as the percent of compliance with correct postures, with a score range of 0%–100%. STATISTICAL ANALYSIS USED: The reliability of CADEP was assessed through intra- and interobserver reproducibility. For the CADEP application, 73 senior year students from the undergraduate course in dentistry were evaluated. The intra- and interexaminer concordance was estimated using the intraclass correlation coefficient (ρ). A descriptive statistical analysis was performed. RESULTS: The reproducibility of evaluator 1 (ρ =0.90; confidence interval [CI] 95%: 0.83–0.94), evaluator 2 (ρ = 0.83; CI 95%: 0.70–0.90), the interexaminer in the first evaluation (ρ = 0.81; CI 95%:0.67–0.89), and in the second one (ρ = 0.76; CI 95%: 0.59–0.87) was classified as good. In the analysis of the compliance, it was verified that moderate compliance was the most prevalent among the evaluated students (65.6%, CI 95%: 60.3%–70.7%). CONCLUSIONS: CADEP was valid and reliable for the assessment of dentistry students’ compliance regarding ergonomic posture requirements. PMID:29693025

Exercise and Posture

Science.gov (United States)

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

[The impact of different sports on posture regulation].

Science.gov (United States)

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

2009-09-01

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

Concomitant Appearance of Pisa Syndrome and Striatal Hand in Parkinson’s Disease

Directory of Open Access Journals (Sweden)

Sanjay Pandey

2011-10-01

Full Text Available Pisa syndrome is (PS usually seen in patients receiving antipsychotic drugs and characterised by lateral flexion of trunk and axial dystonia. It is believed that antipsychotic drugs lead to dopamine blockage causing PS. We describe a Parkinson’s disease patient who was doing well with levodopa/carbidopa for 3 years and developed lateral flexion of trunk. His abnormal posture used to completely improve upon lying down position. He also had striatal hand deformity suggestive of focal dystonia.

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.

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

Science.gov (United States)

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

2012-03-01

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

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

Science.gov (United States)

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

2018-01-01

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

Improved postural control after dynamic balance training in older overweight women.

Science.gov (United States)

Bellafiore, Marianna; Battaglia, Giuseppe; Bianco, Antonino; Paoli, Antonio; Farina, Felicia; Palma, Antonio

2011-01-01

Many studies have reported a greater frequency of falls among older women than men in conditions which stress balance. Previously, we found an improvement in static balance in older women with an increased support surface area and equal load redistribution on both feet, in response to a dynamic balance training protocol. The aim of the present study was to examine whether the same training program and body composition would have effects on the postural control of older overweight women. Ten healthy women (68.67 ± 5.50 yrs; 28.17 ± 3.35 BMI) participated in a five-week physical activity program. This included dynamic balance exercises, such as heel-to-toe walking in different directions, putting their hands on their hips, eyes open (EO) or closed (EC), with a tablet on their heads, going up and down one step, and walking on a mat. Postural stability was assessed before and after training with an optoelectronic platform and a uni-pedal balance performance test. Body composition of the trunk, upper limbs and lower limbs was measured by bio-impedance analysis. The mean speed (MS), medial-lateral MS (MS-x), anterior-posterior MS (MS-y), sway path (SP) and ellipse surface area (ESA) of the pressure center was reduced after training in older women. However, only MS, MS-x, MS-y and SP significantly decreased in bipodalic conditions with EO and MS-y also with EC (punipedal static balance. Our dynamic balance training protocol appears to be feasible, safe and repeatable for older overweight women and to have positive effects in improving their lateral and anterior-posterior postural control, mainly acting on the visual and skeletal muscle components of the balance control system.

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

Science.gov (United States)

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

2002-01-01

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

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

Science.gov (United States)

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

2016-05-04

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

Isolated and combined effects of asymmetric stance and pushing movement on the anticipatory and compensatory postural control.

Science.gov (United States)

Lee, Yun-Ju; Aruin, Alexander S

2014-04-01

To investigate effects of symmetric and asymmetric stance and pushing movement on anticipatory and compensatory postural adjustments (APAs and CPAs). Ten healthy volunteers stood symmetrically (feet parallel) or asymmetrically (one foot forward and the other backward) and pushed a handle with both hands or right or left hand. Bilateral EMG activity of the trunk and leg muscles and center of pressure (COP) displacements in the anterior-posterior (AP) and medial-lateral (ML) directions were recorded and analyzed during the APAs and CPAs. Isolated asymmetry of stance was associated with larger muscle activity of the backward leg while isolated asymmetry of pushing movement induced larger trunk muscle activity on the contralateral side. A combined asymmetry of stance and pushing movement resulted in the increase or decrease of the thigh muscle activity and ML COP displacement depending on whether both asymmetries were induced on the same side of the body or on opposite sides. Both isolated and combined asymmetries affect APAs and CPAs in pushing. Using combined asymmetry of stance and arm movement might be beneficial in performing pushing activity. The outcome of the study provides a basis for studying postural control in individuals with unilateral impairment while performing daily tasks involving pushing. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

DH Iunes

2009-08-01

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

Development of anticipatory postural adjustments during locomotion in children.

Science.gov (United States)

Hirschfeld, H; Forssberg, H

1992-08-01

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

Control of vertical posture while standing on a sliding board and pushing an object.

Science.gov (United States)

Lee, Yun-Ju; Chen, Bing; Liang, Jing-Nong; Aruin, Alexander S

2018-03-01

Voluntary pushing or translation perturbation of the support surface each induces a body perturbation that affects postural control. The objective of the study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments when pushing an object (that induces self-initiated perturbation) and standing on a sliding board (that induces translational perturbation). Thirteen healthy young participants were instructed to push a handle with both hands while standing on a sliding board that was either free to move in the anterior-posterior direction or stationary. Electromyographic activity (EMG) of trunk and lower extremity muscles, center of pressure (COP) displacements, and the forces exerted by the hand were recorded and analyzed during the APA and CPA phases. When the sliding board was free to move during pushing (translation perturbation), onsets of activity of ventral leg muscles and COP displacement were delayed as compared to pushing when standing on a stationary board. Moreover, magnitudes of shank muscle activity and the COP displacement were decreased. When pushing heavier weight, magnitudes of muscle activity, COP displacement, and pushing force increased. The magnitude of activity of the shank muscles during the APA and CPA phases in conditions with translational perturbation varied with the magnitude of the pushing weight. The outcome of the study suggests that the central nervous system prioritizes the pushing task while attenuates the source of additional perturbation induced by translation perturbation. These results could be used in the development of balance re-training paradigms involving pushing weight while standing on a sliding surface.

Foot posture in basketball players with history of the shin splint

Directory of Open Access Journals (Sweden)

Saeed Forghany

2013-07-01

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

Use of Video Analysis System for Working Posture Evaluations

Science.gov (United States)

McKay, Timothy D.; Whitmore, Mihriban

1994-01-01

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

Quantitative Postural Analysis of Children With Congenital Visual Impairment.

Science.gov (United States)

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

2018-01-01

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

Effect of absence of vision on posture.

Science.gov (United States)

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

2016-04-01

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

Nonplantigrade Foot Posture: A Constraint on Dinosaur Body Size

OpenAIRE

Kubo, Tai; Kubo, Mugino O.

2016-01-01

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

Correcting Poor Posture without Awareness or Willpower

Science.gov (United States)

Wernik, Uri

2012-01-01

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

Effects of stimulus pair orientation and hand switching on reaction time estimates of interhemispheric transfer.

Science.gov (United States)

Leblanc-Sirois, Yanick; Braun, Claude M J; Elie-Fortier, Jonathan

2018-03-26

Two behavioral estimates of interhemispheric transfer time, the crossed-uncrossed difference (CUD) and the unilateral field advantage (UFA), are thought to, respectively, index transfer of premotor and visual information across the corpus callosum in neurotypical participants. However, no attempt to manipulate visual and motor contingencies in a set of tasks while measuring the CUD and the UFA has yet been reported. In two go/no-go comparison experiments, stimulus pair orientations were manipulated. The hand of response changed after each correct response in the second, but not the first experiment. No correlation was found between the CUD and the UFA, supporting the hypothesis that these two measures index different types of information transfer across hemispheres. An effect of manipulation of stimulus pair orientation on UFAs was attributed to the homotopy of callosal fibers transferring visual information, while an effect of hand switching on CUDs was attributed mostly to spatial compatibility.

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology.

Science.gov (United States)

Kang, Sung-Won; Choi, Hyeob; Park, Hyung-Il; Choi, Byoung-Gun; Im, Hyobin; Shin, Dongjun; Jung, Young-Giu; Lee, Jun-Young; Park, Hong-Won; Park, Sukyung; Roh, Jung-Sim

2017-11-07

Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable "smart wear" for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB) for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC) embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

A research on the postural stability of a person wearing the lower limb exoskeletal robot by the HAT model.

Science.gov (United States)

Chang, Minsu; Kim, Yeongmin; Lee, Yoseph; Jeon, Doyoung

2017-07-01

This paper proposes a method of detecting the postural stability of a person wearing the lower limb exoskeletal robot with the HAT(Head-Arm-Trunk) model. Previous studies have shown that the human posture is stable when the CoM(Center of Mass) of the human body is placed on the BoS(Base of Support). In the case of the lower limb exoskeletal robot, the motion data, which are used for the CoM estimation, are acquired by sensors in the robot. The upper body, however, does not have sensors in each segment so that it may cause the error of the CoM estimation. In this paper, the HAT(Head-Arm-Trunk) model which combines head, arms, and torso into a single segment is considered because the motion of head and arms are unknown due to the lack of sensors. To verify the feasibility of HAT model, the reflecting markers are attached to each segment of the whole human body and the exact motion data are acquired by the VICON to compare the COM of the full body model and HAT model. The difference between the CoM with full body and that with HAT model is within 20mm for the various motions of head and arms. Based on the HAT model, the XCoM(Extrapolated Center of Mass) which includes the velocity of the CoM is used for prediction of the postural stability. The experiment of making unstable posture shows that the XCoM of the whole body based on the HAT model is feasible to detect the instance of postural instability earlier than the CoM by 20-250 msec. This result may be used for the lower limb exoskeletal robot to prepare for any action to prevent the falling down.

Lung function and postural changes during pregnancy.

Science.gov (United States)

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

1989-11-01

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

Relationship between posterior crossbite and postural alterations in children

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.

Clinical working postures of bachelor of oral health students.

Science.gov (United States)

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

2011-09-01

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

Effect of postural changes on ICP in healthy and ill subjects

DEFF Research Database (Denmark)

Petersen, Lonnie G; Juhler, Marianne

2015-01-01

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

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

Directory of Open Access Journals (Sweden)

В. А. Щирба

2016-09-01

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

Time-of-day influences postural balance in older adults

DEFF Research Database (Denmark)

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

2012-01-01

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

Can smartwatches replace smartphones for posture tracking?

Science.gov (United States)

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

2015-10-22

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

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

Science.gov (United States)

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

2014-01-01

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

A Wireless Accelerometer-Based Body Posture Stability Detection System and Its Application for Meditation Practitioners

Science.gov (United States)

Chang, Kang-Ming; Chen, Sih-Huei; Lee, Hsin-Yi; Ching, Congo Tak-Shing; Huang, Chun-Lung

2012-01-01

The practice of meditation has become an interesting research issue in recent decades. Meditation is known to be beneficial for health improvement and illness reduction and many studies on meditation have been made, from both the physiological and psychological points of view. It is a fundamental requirement of meditation practice to be able to sit without body motion. In this study, a novel body motion monitoring and estimation system has been developed. A wireless tri-axis accelerometer is used to measure body motion. Both a mean and maximum motion index is derived from the square summation of three axes. Two experiments were conducted in this study. The first experiment was to investigate the motion index baseline among three leg-crossing postures. The second experiment was to observe posture dynamics for thirty minute’s meditation. Twenty-six subjects participated in the experiments. In one experiment, thirteen subjects were recruited from an experienced meditation group (meditation experience > 3 years); and the other thirteen subjects were beginners (meditation experience < 1 years). There was a significant posture stability difference between both groups in terms of either mean or maximum parameters (p < 0.05), according to the results of the experiment. Results from another experiment showed that the motion index is different for various postures, such as full-lotus < half-lotus < non-lotus. PMID:23250281

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

Science.gov (United States)

Brulin, Damien; Benezeth, Yannick; Courtial, Estelle

2012-09-01

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

Spatial and temporal analysis of postural control in dyslexic children.

Science.gov (United States)

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

2015-07-01

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

Altered postural control strategies in quiet standing more than 20 years after rupture of the anterior cruciate ligament.

Science.gov (United States)

Stensdotter, Ann-Katrin; Tengman, Eva; Häger, Charlotte

2016-05-01

To explore long-term consequences of anterior cruciate ligament (ACL) rupture on postural sway and control strategies during bilateral quiet standing, in subjects treated with or without reconstructive surgery compared to uninjured controls. 70 individuals who had unilateral ACL rupture 23±2.4 years ago (33 received ACL reconstructive surgery, ACLR, and 37 had physiotherapy only, ACLPT) and 33 uninjured matched controls (CTRL) (mean age 46±5.3) stood quietly with eyes closed for 3min on a firm and on a compliant surface, respectively. Center of pressure (CoP) was registered with a force plate and postural sway was calculated from center of mass (CoM) derived from 3D kinematics. Sway density (SD) analyses of CoP assessed distance and duration of stable phases. The torque controlling postural sway was estimated from CoP-CoM. Comparisons across conditions to CTRL revealed larger CoP-CoM-area in ACLR (p=0.017, CI: 10.95, 143.10), but not in ACLPT. Mean distance between SD-peaks was greater for ACLR (ppostural control efforts than CTRL but without significant differences in postural sway. Control efforts were thus not directly associated with sway and further research should be focused on variance in postural control strategies. Copyright © 2016. Published by Elsevier B.V.

Postural vascular response in human skin: passive and active reactions to alteration of transmural pressure.

Science.gov (United States)

Jepsen, H; Gaehtgens, P

1993-09-01

Laser-Doppler (LD) fluxmetry was performed in the palmar finger skin of healthy subjects to study the mechanisms contributing to the postural vascular response. Local transmural pressure in the skin blood vessels of the region studied was altered for 1 min in two experimental series either by passive movement of the arm to different vertical hand positions relative to heart level or by application of external pressure (-120-180 mmHg) to the finger. Heart and respiratory rate, arterial blood pressure, and LD flux in the contralateral finger (kept at heart level) were measured. The measurements suggest a compound reaction of local (myogenic) and systemic (neurogenic) mechanisms: the local regulatory component appears as a graded active vascular response elicited by passive vessel distension or compression. A systemic component, associated with a single deep inspiration, is frequently observed during the actual movement of the arm. In addition, prolonged holding of the test hand in a given vertical position also elicits a delayed vascular response in the control hand at heart level, which may be generated by volume receptors in the intrathoracic low-pressure system.

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

Directory of Open Access Journals (Sweden)

Burnett Angus F

2008-11-01

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

POSTURAL SHOCK IN PREGNANCY

Science.gov (United States)

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

1955-01-01

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

CHARACTERISTICS OF BODY POSTURE IN THE SAGITTAL PLANE AND FITNESS OF FIRST-FORM PUPILS FROM RURAL AREAS

Directory of Open Access Journals (Sweden)

Hanna Żukowska

2014-07-01

Full Text Available Purpose: to find correlations between characteristics of body posture in the sagittal plane and fitness and endurance of first-form children from rural areas. Material: an analysis of more than 30 sources of scientific and educational literature. Results: the study involved 209 children, including 102 girls and 107 boys. They were children who lived in the country since they were born. To assess particular characteristics of body posture, the children were studied by means of the measuring equipment using the projection Moiré system. Motor skills were estimated using selected EUROFIT physical fitness tests (sitting forward bend, standing broad jump, handgrip, sit-and-reach, bent arm hang and 10 x 5 m shuttle run. The level of physical endurance was evaluated with the Harvard Step Test modified by Montoye. Conclusions: the conducted research reveals statistically significant correlations between the characteristics of body posture in the sagittal plane and selected EUROFIT physical fitness tests and physical endurance of the children involved in the study.

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...

Multi-joint postural behavior in patients with knee osteoarthritis.

Science.gov (United States)

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

2015-12-01

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

Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

Science.gov (United States)

Islam, Md Anamul; Sundaraj, Kenneth; Ahmad, R Badlishah; Sundaraj, Sebastian; Ahamed, Nizam Uddin; Ali, Md Asraf

2014-01-01

In mechanomyography (MMG), crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity. The aim of the present study was two-fold: i) to quantify the level of crosstalk in the mechanomyographic (MMG) signals from the longitudinal (Lo), lateral (La) and transverse (Tr) axes of the extensor digitorum (ED), extensor carpi ulnaris (ECU) and flexor carpi ulnaris (FCU) muscles during isometric wrist flexion (WF) and extension (WE), radial (RD) and ulnar (UD) deviations; and ii) to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures. Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg) participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups. The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38) = 14-63, pmovement research, especially for the examination of muscle mechanics during various types of the wrist postures.

Advantages and disadvantages of stiffness instructions when studying postural control.

Science.gov (United States)

Bonnet, Cédrick T

2016-05-01

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

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

NARCIS (Netherlands)

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

2012-01-01

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

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

NARCIS (Netherlands)

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

2012-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

Postural & striatal deformities in Parkinson`s disease: Are these rare?

Directory of Open Access Journals (Sweden)

Sanjay Pandey

2016-01-01

Full Text Available Parkinson`s disease (PD is the most common neurodegenerative disease and is characterized by tremor, rigidity and akinesia. Diagnosis is clinical in the majority of the patients. Patients with PD may have stooped posture but some of them develop different types of postural and striatal deformities. Usually these deformities are more common in atypical parkinsonian disorders such as progressive supranuclear palsy and multisystem atrophy. But in many studies it has been highlighted that these may also be present in approximately one third of PD patients leading to severe disability. These include antecollis or dropped head, camptocormia, p0 isa syndrome, scoliosis, striatal hands and striatal toes. The pathogenesis of these deformities is a complex combination of central and peripheral influences such as rigidity, dystonia and degenerative skeletal changes. Duration of parkinsonism symptoms is an important risk factor and in majority of the patients these deformities are seen in advanced statge of the disease. The patients with such symptoms may initially respond to dopaminergic medications but if not intervened they may become fixed and difficult to treat. Pain and restriction of movement are most common clinical manifestations and these may mimick symptoms of musculoskeletal disorders like rheumatoid arthritis. Early diagnosis is important as the patients may respond to adjustment in dopaminergic medications. Recent advances such as deep brain stimulation (DBS and ultrasound guided botulinum toxin injection are helpful in management of these deformities in patients with PD.

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

Science.gov (United States)

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

2017-12-01

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

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

Directory of Open Access Journals (Sweden)

Ana Carla Ramos Vieira da Costa

2014-01-01

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

Is postural control affected by expertise in alpine skiing?

OpenAIRE

Noe, F; Paillard, T

2005-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

Pérennou, Dominic

2006-01-01

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

The use of intermuscular coherence analysis as a novel approach to detect age-related changes on postural muscle synergy.

Science.gov (United States)

Degani, Adriana M; Leonard, Charles T; Danna-Dos-Santos, Alessander

2017-08-24

The overall goal of this study was to investigate potential adaptations brought about by the natural processes of aging on the coordination of postural muscles. Considering the progressive and non-homogeneous deterioration of sensorimotor and neuromuscular systems as the individual grows older, it was hypothesized that aging is associated with a reorganization of synergistic mechanisms controlling postural muscles. Therefore, the presence, distribution, and strength of correlated neural inputs to three posterior postural muscles were measured by intermuscular coherence estimations at a low frequency band (0-55Hz). Nine healthy young adults and thirteen healthy older adults performed ten trials of a perturbed task: bipedal stance while holding a five kg load for fifteen seconds. Estimates of intermuscular coherence for each pair of electromyographic signals (soleus and biceps femoris, soleus and erector spinae, and biceps femoris and erector spinae) were computed. Results revealed significantly stronger levels of synchronization of posterior muscles within 0-10Hz in seniors compared to young adults. In addition, seniors presented similar spectra of intermuscular coherence within 0-55Hz for all three muscle pairs analyzed. These findings provide valuable information regarding compensatory mechanisms adopted by older adults to control balance. The age-related reorganization of neural drive controlling posterior postural muscles revealing a stronger synchronization within 0-10Hz might be related to the faster body sway and muscle co-activation patterns usually observed in this population. Finally, this study supports the use of Intermuscular Coherence Analysis as a sensitive method to detect age-related changes in multi-muscle control. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2016-05-01

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

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

Science.gov (United States)

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

2016-01-01

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

Neurons in red nucleus and primary motor cortex exhibit similar responses to mechanical perturbations applied to the upper-limb during posture

Directory of Open Access Journals (Sweden)

Troy Michael Herter

2015-04-01

Full Text Available Primary motor cortex (M1 and red nucleus (RN are brain regions involved in limb motor control. Both structures are highly interconnected with the cerebellum and project directly to the spinal cord, although the contribution of RN is smaller than M1. It remains uncertain whether RN and M1 serve similar or distinct roles during posture and movement. Many neurons in M1 respond rapidly to mechanical disturbances of the limb, but it remains unclear whether RN neurons also respond to such limb perturbations. We have compared discharges of single neurons in RN (n = 49 and M1 (n = 109 of one monkey during a postural perturbation task. Neural responses to whole-limb perturbations were examined by transiently applying (300 ms flexor or extensor torques to the shoulder and/or elbow while the monkeys attempted to maintain a static hand posture. Relative to baseline discharges before perturbation onset, perturbations evoked rapid (<100 ms changes of neural discharges in many RN (28 of 49, 57% and M1 (43 of 109, 39% neurons. In addition to exhibiting a greater proportion of perturbation-related neurons, RN neurons also tended to exhibit higher peak discharge frequencies in response to perturbations than M1 neurons. Importantly, neurons in both structures exhibited similar response latencies and tuning properties (preferred torque directions and tuning widths in joint-torque space. Proximal arm muscles also displayed similar tuning properties in joint-torque space. These results suggest that RN is more sensitive than M1 to mechanical perturbations applied during postural control but both structures may play a similar role in feedback control of posture.

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

Science.gov (United States)

Porter, D; Michael, S; Kirkwood, C

2010-09-01

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

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

Science.gov (United States)

Grabara, Małgorzata

2018-02-06

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

Spinal curvature and characteristics of postural change in pregnant women.

Science.gov (United States)

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

2012-07-01

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

Prism adaptation improves postural imbalance in neglect patients

NARCIS (Netherlands)

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

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Boy Nurtjahyo

2012-02-01

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

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

Science.gov (United States)

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

2010-01-01

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

Nuclear Posture Review

Science.gov (United States)

2018-02-01

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

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology

Directory of Open Access Journals (Sweden)

Sung-Won Kang

2017-11-01

Full Text Available Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable “smart wear” for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

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

Science.gov (United States)

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

2015-01-01

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

Differences in body composition and prevalence for postural ...

African Journals Online (AJOL)

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

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

Directory of Open Access Journals (Sweden)

Hatice Esen

2013-01-01

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

Postural activity monitoring for increasing safety in bomb disposal missions

International Nuclear Information System (INIS)

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

2009-01-01

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

Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults.

Science.gov (United States)

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

2016-01-01

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

Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults.

Directory of Open Access Journals (Sweden)

Fabianne Furtado

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

Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs.

Science.gov (United States)

Taylor, Michael P

2014-01-01

Attempts to reconstruct the neutral neck posture of sauropod dinosaurs, or indeed any tetrapod, are doomed to failure when based only on the geometry of the bony cervical vertebrae. The thickness of the articular cartilage between the centra of adjacent vertebrae affects posture. It extends (raises) the neck by an amount roughly proportional to the thickness of the cartilage. It is possible to quantify the angle of extension at an intervertebral joint: it is roughly equal, in radians, to the cartilage thickness divided by the height of the zygapophyseal facets over the centre of rotation. Applying this formula to published measurements of well-known sauropod specimens suggests that if the thickness of cartilage were equal to 4.5%, 10% or 18% of centrum length, the neutral pose of the Apatosaurus louisae holotype CM 3018 would be extended by an average of 5.5, 11.8 or 21.2 degrees, respectively, at each intervertebral joint. For the Diplodocus carnegii holotype CM 84, the corresponding angles of additional extension are even greater: 8.4, 18.6 or 33.3 degrees. The cartilaginous neutral postures (CNPs) calculated for 10% cartilage-the most reasonable estimate-appear outlandish. But it must be remembered that these would not have been the habitual life postures, because tetrapods habitually extend the base of their neck and flex the anterior part, yielding the distinctive S-curve most easily seen in birds.

The impact of elbow and knee joint lesions on abnormal gait and posture of sows

Directory of Open Access Journals (Sweden)

Jørgensen Bente

2008-02-01

Full Text Available Abstract Background Joint lesions occur widespread in the Danish sow population and they are the most frequent cause for euthanasia. Clinically, it is generally impossible to differentiate between various types of non-inflammatory joint lesions. Consequently, it is often necessary to perform a post mortem examination in order to diagnose these lesions. A study was performed in order to examine the relation of abnormal gait and posture in sows with specific joint lesions, and thereby obtaining a clinical diagnostic tool, to be used by farmers and veterinarians for the evaluation of sows with joint problems. Methods The gait, posture and lesions in elbow- and knee joints of 60 randomly selected sows from one herd were scored clinically and pathologically. Associations between the scorings were estimated. Results The variables 'fore- and hind legs turned out' and 'stiff in front and rear' were associated with lesions in the elbow joint, and the variables 'hind legs turned out' and 'stiff in rear' were associated with lesions in the knee joint. Conclusion It was shown that specified gait and posture variables reflected certain joint lesions. However, further studies are needed to strengthen and optimize the diagnostic tool.

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…

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

Science.gov (United States)

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

2016-03-01

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

Shooting performance is related to forearm temperature and hand tremor size.

Science.gov (United States)

Lakie, M; Villagra, F; Bowman, I; Wilby, R

1995-08-01

The changes in postural tremor of the hand and the subsequent effect on shooting performance produced by moderate cooling and heating of the forearm were studied in six subjects. Cooling produced a large decrease in tremor size of the ipsilateral hand, whereas warming the limb produced an increase in tremor size. Cooling or warming the forearm did not change the peak frequency of tremor significantly, which was quite stable for each subject. The improvement in shooting performance after cooling the forearm, as measured by grouping pattern of the shots, reached statistical significance and warming caused a significant worsening. This measure of performance was shown to correlate (r = 0.776) inversely with tremor size. The causes and implications of these changes are discussed. It is suggested that local cooling may be useful for people who wish temporarily to reduce tremor in order to improve dexterity for shooting and for other purposes.

Increased dynamic regulation of postural tone through Alexander Technique training.

Science.gov (United States)

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

2011-02-01

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

Postural control in chronic obstructive pulmonary disease: a systematic review

Directory of Open Access Journals (Sweden)

Porto EF

2015-06-01

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

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

Directory of Open Access Journals (Sweden)

Ewa Bieć

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

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

Science.gov (United States)

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

2013-01-01

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

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

Directory of Open Access Journals (Sweden)

Regiane Luz Carvalho

2008-09-01

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

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

Science.gov (United States)

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

1996-10-01

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

Postural health in women: the role of physiotherapy.

Science.gov (United States)

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

2005-05-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Ho Joon Jeon

2017-01-01

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

Evaluation of body posture in nursing students

Directory of Open Access Journals (Sweden)

Marília Fernandes Andrade

2017-08-01

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

Is there a relationship between head posture and craniomandibular pain?

Science.gov (United States)

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

2002-11-01

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

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

Science.gov (United States)

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

2016-01-01

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

FATIGUE AND FAULTY POSTURE CONNECTION AMONG CHILDREN, DIAGNOSED WITH DYSARTHRIA

Directory of Open Access Journals (Sweden)

Andrejeva Julija

2015-08-01

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

Fatigue and faulty posture connection among children, diagnosed with dysarthria

Directory of Open Access Journals (Sweden)

Julija Andrejeva

2015-08-01

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

Enhancing creativity: Proper body posture meets proper emotion.

Science.gov (United States)

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

2017-02-01

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

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

Science.gov (United States)

Sohn, M Hongchul; Ting, Lena H

2016-01-01

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

The Control of Posture in Newly Standing Infants is Task Dependent

Science.gov (United States)

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

2012-01-01

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

Aging causes a reorganization of cortical and spinal control of posture

Directory of Open Access Journals (Sweden)

Selma ePapegaaij

2014-03-01

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

An EMG-Controlled Robotic Hand Exoskeleton for Bilateral Rehabilitation.

Science.gov (United States)

Leonardis, Daniele; Barsotti, Michele; Loconsole, Claudio; Solazzi, Massimiliano; Troncossi, Marco; Mazzotti, Claudio; Castelli, Vincenzo Parenti; Procopio, Caterina; Lamola, Giuseppe; Chisari, Carmelo; Bergamasco, Massimo; Frisoli, Antonio

2015-01-01

This paper presents a novel electromyography (EMG)-driven hand exoskeleton for bilateral rehabilitation of grasping in stroke. The developed hand exoskeleton was designed with two distinctive features: (a) kinematics with intrinsic adaptability to patient's hand size, and (b) free-palm and free-fingertip design, preserving the residual sensory perceptual capability of touch during assistance in grasping of real objects. In the envisaged bilateral training strategy, the patient's non paretic hand acted as guidance for the paretic hand in grasping tasks. Grasping force exerted by the non paretic hand was estimated in real-time from EMG signals, and then replicated as robotic assistance for the paretic hand by means of the hand-exoskeleton. Estimation of the grasping force through EMG allowed to perform rehabilitation exercises with any, non sensorized, graspable objects. This paper presents the system design, development, and experimental evaluation. Experiments were performed within a group of six healthy subjects and two chronic stroke patients, executing robotic-assisted grasping tasks. Results related to performance in estimation and modulation of the robotic assistance, and to the outcomes of the pilot rehabilitation sessions with stroke patients, positively support validity of the proposed approach for application in stroke rehabilitation.

Inverse Kinematics for Upper Limb Compound Movement Estimation in Exoskeleton-Assisted Rehabilitation.

Science.gov (United States)

Cortés, Camilo; de Los Reyes-Guzmán, Ana; Scorza, Davide; Bertelsen, Álvaro; Carrasco, Eduardo; Gil-Agudo, Ángel; Ruiz-Salguero, Oscar; Flórez, Julián

2016-01-01

Robot-Assisted Rehabilitation (RAR) is relevant for treating patients affected by nervous system injuries (e.g., stroke and spinal cord injury). The accurate estimation of the joint angles of the patient limbs in RAR is critical to assess the patient improvement. The economical prevalent method to estimate the patient posture in Exoskeleton-based RAR is to approximate the limb joint angles with the ones of the Exoskeleton. This approximation is rough since their kinematic structures differ. Motion capture systems (MOCAPs) can improve the estimations, at the expenses of a considerable overload of the therapy setup. Alternatively, the Extended Inverse Kinematics Posture Estimation (EIKPE) computational method models the limb and Exoskeleton as differing parallel kinematic chains. EIKPE has been tested with single DOF movements of the wrist and elbow joints. This paper presents the assessment of EIKPE with elbow-shoulder compound movements (i.e., object prehension). Ground-truth for estimation assessment is obtained from an optical MOCAP (not intended for the treatment stage). The assessment shows EIKPE rendering a good numerical approximation of the actual posture during the compound movement execution, especially for the shoulder joint angles. This work opens the horizon for clinical studies with patient groups, Exoskeleton models, and movements types.

Inverse Kinematics for Upper Limb Compound Movement Estimation in Exoskeleton-Assisted Rehabilitation

Science.gov (United States)

Cortés, Camilo; de los Reyes-Guzmán, Ana; Scorza, Davide; Bertelsen, Álvaro; Carrasco, Eduardo; Gil-Agudo, Ángel; Ruiz-Salguero, Oscar; Flórez, Julián

2016-01-01

Robot-Assisted Rehabilitation (RAR) is relevant for treating patients affected by nervous system injuries (e.g., stroke and spinal cord injury). The accurate estimation of the joint angles of the patient limbs in RAR is critical to assess the patient improvement. The economical prevalent method to estimate the patient posture in Exoskeleton-based RAR is to approximate the limb joint angles with the ones of the Exoskeleton. This approximation is rough since their kinematic structures differ. Motion capture systems (MOCAPs) can improve the estimations, at the expenses of a considerable overload of the therapy setup. Alternatively, the Extended Inverse Kinematics Posture Estimation (EIKPE) computational method models the limb and Exoskeleton as differing parallel kinematic chains. EIKPE has been tested with single DOF movements of the wrist and elbow joints. This paper presents the assessment of EIKPE with elbow-shoulder compound movements (i.e., object prehension). Ground-truth for estimation assessment is obtained from an optical MOCAP (not intended for the treatment stage). The assessment shows EIKPE rendering a good numerical approximation of the actual posture during the compound movement execution, especially for the shoulder joint angles. This work opens the horizon for clinical studies with patient groups, Exoskeleton models, and movements types. PMID:27403420

Inverse Kinematics for Upper Limb Compound Movement Estimation in Exoskeleton-Assisted Rehabilitation

Directory of Open Access Journals (Sweden)

Camilo Cortés

2016-01-01

Full Text Available Robot-Assisted Rehabilitation (RAR is relevant for treating patients affected by nervous system injuries (e.g., stroke and spinal cord injury. The accurate estimation of the joint angles of the patient limbs in RAR is critical to assess the patient improvement. The economical prevalent method to estimate the patient posture in Exoskeleton-based RAR is to approximate the limb joint angles with the ones of the Exoskeleton. This approximation is rough since their kinematic structures differ. Motion capture systems (MOCAPs can improve the estimations, at the expenses of a considerable overload of the therapy setup. Alternatively, the Extended Inverse Kinematics Posture Estimation (EIKPE computational method models the limb and Exoskeleton as differing parallel kinematic chains. EIKPE has been tested with single DOF movements of the wrist and elbow joints. This paper presents the assessment of EIKPE with elbow-shoulder compound movements (i.e., object prehension. Ground-truth for estimation assessment is obtained from an optical MOCAP (not intended for the treatment stage. The assessment shows EIKPE rendering a good numerical approximation of the actual posture during the compound movement execution, especially for the shoulder joint angles. This work opens the horizon for clinical studies with patient groups, Exoskeleton models, and movements types.

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…

Measurement of action forces and posture to determine the lumbar load of healthcare workers during care activities with patient transfers.

Science.gov (United States)

Theilmeier, Andreas; Jordan, Claus; Luttmann, Alwin; Jäger, Matthias

2010-11-01

Moving patients or other care activities with manual patient handling is characterized by high mechanical load on the lumbar spine of healthcare workers (HCWs). During the patient transfer activity, the caregivers exert lifting, pulling, and pushing forces varying over time with respect to amplitude and direction. Furthermore, the caregivers distinctly change their posture and frequently obtain postures asymmetrical to the median sagittal plane, including lateral bending and turning the trunk. This paper describes a procedure to determine lumbar load during patient transfer supported by measurement techniques and an exemplary application; this methodology represents the basis of a complex research project, the third 'Dortmund Lumbar Load Study (DOLLY 3)'. Lumbar load was determined by simulation calculations using a comprehensive biomechanical model ('The Dortmunder'). As the main influencing factors, the hand forces of the caregiver exerted during typical patient transfers and the posture and movements of the HCW were recorded in laboratory studies. The action forces were determined three-dimensionally with the help of a newly developed 'measuring bed', two different 'measuring chairs', a 'measuring bathtub', and a 'measuring floor'. To capture the forces during transfers in or at the bed, a common hospital bed was equipped with an additional framework, which is attached to the bedstead and connected to the bedspring frame via three-axial force sensors at the four corners. The other measuring systems were constructed similarly. Body movements were recorded using three-dimensional optoelectronic recording tools and video recordings. The posture and force data served as input data for the quantification of various lumbar-load indicators.

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

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

OpenAIRE

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

2007-01-01

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

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

OpenAIRE

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

1991-01-01

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

Fractal time series analysis of postural stability in elderly and control subjects

Directory of Open Access Journals (Sweden)

Doussot Michel

2007-05-01

Full Text Available Abstract Background The study of balance using stabilogram analysis is of particular interest in the study of falls. Although simple statistical parameters derived from the stabilogram have been shown to predict risk of falls, such measures offer little insight into the underlying control mechanisms responsible for degradation in balance. In contrast, fractal and non-linear time-series analysis of stabilograms, such as estimations of the Hurst exponent (H, may provide information related to the underlying motor control strategies governing postural stability. In order to be adapted for a home-based follow-up of balance, such methods need to be robust, regardless of the experimental protocol, while producing time-series that are as short as possible. The present study compares two methods of calculating H: Detrended Fluctuation Analysis (DFA and Stabilogram Diffusion Analysis (SDA for elderly and control subjects, as well as evaluating the effect of recording duration. Methods Centre of pressure signals were obtained from 90 young adult subjects and 10 elderly subjects. Data were sampled at 100 Hz for 30 s, including stepping onto and off the force plate. Estimations of H were made using sliding windows of 10, 5, and 2.5 s durations, with windows slid forward in 1-s increments. Multivariate analysis of variance was used to test for the effect of time, age and estimation method on the Hurst exponent, while the intra-class correlation coefficient (ICC was used as a measure of reliability. Results Both SDA and DFA methods were able to identify differences in postural stability between control and elderly subjects for time series as short as 5 s, with ICC values as high as 0.75 for DFA. Conclusion Both methods would be well-suited to non-invasive longitudinal assessment of balance. In addition, reliable estimations of H were obtained from time series as short as 5 s.

Usefulness of posture training for patients with temporomandibular disorders.

Science.gov (United States)

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

2000-02-01

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

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

Science.gov (United States)

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

2017-05-01

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

Factors influencing hand/eye synchronicity in the computer age.

Science.gov (United States)

Grant, A H

1992-09-01

In using a computer, the relation of vision to hand/finger actuated keyboard usage in performing fine motor-coordinated functions is influenced by the physical location, size, and collective placement of the keys. Traditional nonprehensile flat/rectangular keyboard applications usually require a high and nearly constant level of visual attention. Biometrically shaped keyboards would allow for prehensile hand-posturing, thus affording better tactile familiarity with the keys, requiring less intense and less constant level of visual attention to the task, and providing a greater measure of freedom from having to visualize the key(s). Workpace and related physiological changes, aging, onset of monocularization (intermittent lapsing of binocularity for near vision) that accompanies presbyopia, tool colors, and background contrast are factors affecting constancy of visual attention to task performance. Capitas extension, excessive excyclotorsion, and repetitive strain injuries (such as carpal tunnel syndrome) are common and debilitating concomitants to computer usage. These problems can be remedied by improved keyboard design. The salutary role of mnemonics in minimizing visual dependency is discussed.

3D pose estimation and motion analysis of the articulated human hand-forearm limb in an industrial production environment

Science.gov (United States)

Hahn, Markus; Barrois, Björn; Krüger, Lars; Wöhler, Christian; Sagerer, Gerhard; Kummert, Franz

2010-09-01

This study introduces an approach to model-based 3D pose estimation and instantaneous motion analysis of the human hand-forearm limb in the application context of safe human-robot interaction. 3D pose estimation is performed using two approaches: The Multiocular Contracting Curve Density (MOCCD) algorithm is a top-down technique based on pixel statistics around a contour model projected into the images from several cameras. The Iterative Closest Point (ICP) algorithm is a bottom-up approach which uses a motion-attributed 3D point cloud to estimate the object pose. Due to their orthogonal properties, a fusion of these algorithms is shown to be favorable. The fusion is performed by a weighted combination of the extracted pose parameters in an iterative manner. The analysis of object motion is based on the pose estimation result and the motion-attributed 3D points belonging to the hand-forearm limb using an extended constraint-line approach which does not rely on any temporal filtering. A further refinement is obtained using the Shape Flow algorithm, a temporal extension of the MOCCD approach, which estimates the temporal pose derivative based on the current and the two preceding images, corresponding to temporal filtering with a short response time of two or at most three frames. Combining the results of the two motion estimation stages provides information about the instantaneous motion properties of the object. Experimental investigations are performed on real-world image sequences displaying several test persons performing different working actions typically occurring in an industrial production scenario. In all example scenes, the background is cluttered, and the test persons wear various kinds of clothes. For evaluation, independently obtained ground truth data are used. [Figure not available: see fulltext.

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

Science.gov (United States)

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

2015-06-18

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

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

Directory of Open Access Journals (Sweden)

Toscano, Carla Fabiana da Silva

2011-04-01

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

The study of postural workload in assembly of furniture upholstery

OpenAIRE

Marek Lasota Andrzej; Hankiewicz Krzysztof

2017-01-01

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