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Sample records for adolescent standing postural

  1. Trajectories of childhood body mass index are associated with adolescent sagittal standing posture.

    PubMed

    Smith, Anne J; O'Sullivan, Peter Bruce; Beales, Darren John; de Klerk, Nick; Straker, Leon M

    2011-06-01

    To identify distinct age-related trajectory classes of body mass index (BMI) z-scores from childhood to adolescence, and to examine the association of these trajectories with measures of standing sagittal spinal alignment at 14 years of age. Adolescents participating in the Western Australian Pregnancy Cohort (Raine) Study contributed data to the study (n=1 373). Age- and gender-specific z-scores for BMI were obtained from height and weight at the ages of 3, 5, 10 and 14 years. Latent class group analysis was used to identify six distinct trajectory classes of BMI z-score. At the age of 14 years, adolescents were categorised into one of four subgroups of sagittal spinal posture using k-means cluster analysis of photographic measures of lumbar lordosis, thoracic kyphosis and trunk sway. Regression modeling was used to assess the relationship between postural angles and subgroups, and different BMI trajectory classes, adjusting for gender. Six trajectory classes of BMI z-score were estimated: Very Low (4%), Low (24%), Average (34%), Ascending (6%), Moderate High (26%) and Very High (6%). The proportions of postural subgroups at age 14 were; Neutral (29%), Flat (22%), Sway (27%) and Hyperlordotic (22%). BMI trajectory class was strongly associated with postural subgroup, with significantly higher proportions of adolescents in the Very High, High and Ascending BMI trajectory classes displaying a Hyperlordotic or Sway posture than a Neutral posture at age 14. This prospective study provides evidence that childhood obesity, and how it develops, is associated with standing sagittal postural alignment in adolescence.

  2. Intrarater and interrater reliability of photographic measurement of upper-body standing posture of adolescents.

    PubMed

    Ruivo, Rodrigo Miguel; Pezarat-Correia, Pedro; Carita, Ana Isabel

    2015-01-01

    The purposes of this study were to determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and analyze differences in postural angles between sexes. This cross-sectional study was conducted in 2 secondary schools in Portugal where 275 adolescent students (146 females and 129 males) aged 15 to 17 years were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and the Postural Assessment Software. For interrater reliability, all of the intraclass correlation coefficient (ICC) values for the 3 angles were higher than 0.85. For intrarater reliability, the ICC values for the sagittal head angle, shoulder angle, and cervical angle were 0.83, 0.78, and 0.66, respectively. Mean values of sagittal head, cervical, and shoulder angles were 17.2° ± 5.7°, 47.4° ± 5.2°, and 51.4° ± 8.5°, respectively. Anterior head carriage was demonstrated by 68% of the adolescents, whereas 58% had protraction of the shoulder(s). Males had significantly higher mean cervical and sagittal head angles. Forward head posture and protracted shoulders were common postural disorders in adolescents 15 to 17 years old, with females revealing a lower mean cervical angle. The intrarater and interrater evaluation of standing sagittal posture of the cervical spine and shoulders by photogrammetry was reliable. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  3. The effect of backpack weight on the standing posture and balance of schoolgirls with adolescent idiopathic scoliosis and normal controls.

    PubMed

    Chow, Daniel H K; Kwok, Monica L Y; Cheng, Jack C Y; Lao, Miko L M; Holmes, Andrew D; Au-Yang, Alexander; Yao, Fiona Y D; Wong, M S

    2006-10-01

    Concerns have been raised regarding the effect of carrying a backpack on adolescent posture and balance, but the effect of backpack loading combined with other factors affecting balance, such as adolescent idiopathic scoliosis (AIS), has not been determined. This study examines the effects of backpack load on the posture and balance of schoolgirls with AIS and normal controls. The standing posture of 26 schoolgirls with mild AIS (mean age 13, Cobb angle 10-25 degrees ) and 20 age-matched normal schoolgirls were recorded without a backpack and while carrying a standard dual-strap backpack loaded at 7.5%, 10%, 12.5% and 15% of the subject's bodyweight (BW). Kinematics of the pelvis, trunk and head were recorded using a motion analysis system and centre of pressure (COP) data were recorded using a force platform. Reliable COP data could only be derived for 13 of the subjects with AIS. Increasing backpack load causes a significantly increased flexion of the trunk in relation to the pelvis and extension of the head in relation to the trunk, as well as increased antero-posterior range of COP motion. While backpack load appears to affect balance predominantly in the antero-posterior direction, differences between groups were more evident in the medio-lateral direction, with AIS subjects showing poor balance in this direction. Overall, carrying a backpack causes similar sagittal plane changes in posture and balance in both normal and AIS groups. Load size or subject group did not influence balance, but the additive effect of backpack carrying and AIS on postural control alters the risk of fall in this population. Therefore, load limit recommendations based on normal subjects should not be applicable to subjects with AIS.

  4. Sagittal standing posture and its association with spinal pain: a school-based epidemiological study of 1196 Flemish adolescents before age at peak height velocity.

    PubMed

    Dolphens, Mieke; Cagnie, Barbara; Coorevits, Pascal; Vanderstraeten, Guy; Cardon, Greet; Dʼhooge, Roseline; Danneels, Lieven

    2012-09-01

    Cross-sectional baseline data set on the sagittal standing posture of 1196 adolescents. To describe and quantify common variations in the sagittal standing alignment in boys and girls who are in the same phase of growth and to explore the association between habitual standing posture and measures for spinal pain. Data on postural characteristics and spinal pain measures in adolescence are sparse, especially when somatic and biological maturity status is to be considered. Our understanding of the relationship between standing posture in the sagittal plane and spinal pain is also deficient. A total of 639 boys (age [mean ± SD], 12.6 ± 0.54 yr) and 557 girls (10.6 ± 0.47 yr), with predicted years from peak height velocity (PHV) being 1.2 ± 0.71 and 1.2 ± 0.59 pre-PHV, respectively, were studied. Postural examination included the assessment of global alignment and local spinopelvic characteristics, using post hoc analyses of digital images and direct body measurements (palpation, digital inclinometry, and wheeled accelerometry). Spinal pain experience was assessed by questionnaire. A wide interindividual variation in sagittal posture characteristics was observed. Logistic regression analyses yielded global alignment parameters to be associated with low back pain (lifetime prevalence), neck pain (lifetime prevalence, 1-mo prevalence, and doctor visit), and thoracic spine pain (doctor visit) outcome measures. None of the included local spinopelvic parameters could be identified as an associated factor with measures of spinal pain. The orientation of gross body segments with respect to the gravity line seems superior to local spinopelvic features in terms of clinical importance, at least in the current pre-PHV cohort. Opportunities may exist for postural subgrouping strategies to begin with global alignment parameters in order to gain further insight into the relationship between sagittal alignment and the relative risk of developing spinal pain/seeking medical

  5. Pelvic morphology, body posture and standing balance characteristics of adolescent able-bodied and idiopathic scoliosis girls.

    PubMed

    Stylianides, Georgios A; Dalleau, Georges; Begon, Mickaël; Rivard, Charles-Hilaire; Allard, Paul

    2013-01-01

    The purpose of this study was to determine how pelvic morphology, body posture, and standing balance variables of scoliotic girls differ from those of able-bodied girls, and to classify neuro-biomechanical variables in terms of a lower number of unobserved variables. Twenty-eight scoliotic and twenty-five non-scoliotic able-bodied girls participated in this study. 3D coordinates of ten anatomic body landmarks were used to describe pelvic morphology and trunk posture using a Flock of Birds system. Standing balance was measured using a force plate to identify the center of pressure (COP), and its anteroposterior (AP) and mediolateral (ML) displacements. A multivariate analysis of variance (MANOVA) was performed to determine differences between the two groups. A factor analysis was used to identify factors that best describe both groups. Statistical differences were identified between the groups for each of the parameter types. While spatial orientation of the pelvis was similar in both groups, five of the eight trunk postural variables of the scoliotic group were significantly different that the able-bodied group. Also, five out of the seven standing balance variables were higher in the scoliotic girls. Approximately 60% of the variation is supported by 4 factors that can be associated with a set of variables; standing balance variables (factor 1), body posture variables (factor 2), and pelvic morphology variables (factors 3 and 4). Pelvic distortion, body posture asymmetry, and standing imbalance are more pronounced in scoliotic girls, when compared to able-bodied girls. These findings may be beneficial when addressing balance and ankle proprioception exercises for the scoliotic population.

  6. Pelvic Morphology, Body Posture and Standing Balance Characteristics of Adolescent Able-Bodied and Idiopathic Scoliosis Girls

    PubMed Central

    Stylianides, Georgios A.; Dalleau, Georges; Begon, Mickaël; Rivard, Charles-Hilaire; Allard, Paul

    2013-01-01

    The purpose of this study was to determine how pelvic morphology, body posture, and standing balance variables of scoliotic girls differ from those of able-bodied girls, and to classify neuro-biomechanical variables in terms of a lower number of unobserved variables. Twenty-eight scoliotic and twenty-five non-scoliotic able-bodied girls participated in this study. 3D coordinates of ten anatomic body landmarks were used to describe pelvic morphology and trunk posture using a Flock of Birds system. Standing balance was measured using a force plate to identify the center of pressure (COP), and its anteroposterior (AP) and mediolateral (ML) displacements. A multivariate analysis of variance (MANOVA) was performed to determine differences between the two groups. A factor analysis was used to identify factors that best describe both groups. Statistical differences were identified between the groups for each of the parameter types. While spatial orientation of the pelvis was similar in both groups, five of the eight trunk postural variables of the scoliotic group were significantly different that the able-bodied group. Also, five out of the seven standing balance variables were higher in the scoliotic girls. Approximately 60% of the variation is supported by 4 factors that can be associated with a set of variables; standing balance variables (factor 1), body posture variables (factor 2), and pelvic morphology variables (factors 3 and 4). Pelvic distortion, body posture asymmetry, and standing imbalance are more pronounced in scoliotic girls, when compared to able-bodied girls. These findings may be beneficial when addressing balance and ankle proprioception exercises for the scoliotic population. PMID:23875021

  7. A new posture measurement method for measuring intrinsic standing posture.

    PubMed

    Kawakami, Shigehisa; Kodama, Naoki; Maeda, Naoto; Sakamoto, Shunichi; Minagi, Shogo

    2014-04-01

    Although body posture in relation to the dental condition has been of great interest in the dental profession, rumination bias has been a substantial obstacle to achieving a reliable objective evaluation of the intrinsic body posture. The aim of this study was to establish a posture control protocol that would minimize the effect of bias. Fifteen healthy male volunteers (23-33 years of age) participated in this study. The posture movement was recorded for 10 seconds by a three-dimensional motion capture system. The experiment was performed on four different days. The posture was most stable at 4-5 seconds after the start of the front bulb gaze (the mean coefficient of variation ranged from 0.1 to 44.1). The intraclass correlation coefficients for four days were 0.871-0.975 (P < or = 0.001). It was concluded that the use of this measurement method helped in producing a reliable intrinsic standing posture where unbiased evaluation of the effect of any intervention on the body posture is researched.

  8. Sagittal evaluation of usual standing and sitting spinal posture.

    PubMed

    Claeys, Kurt; Brumagne, Simon; Deklerck, Jan; Vanderhaeghen, Jacques; Dankaerts, Wim

    2016-04-01

    Postural rehabilitation often plays an important role in the management of non-specific low back pain. While cervical and lumbar correlations have been demonstrated previously, the different role of the pelvis and the thoracic spine for postural control in sitting and standing remains unclear. The aim of this study was to investigate postural correlations between all spinal regions in standing and sitting. Based on digital photographs eight postural angles were analyzed in 99 young healthy persons. Pearson correlations between different postural angles were calculated. In sitting pelvic tilt demonstrated mostly medium correlations with five out of seven other postural angles, compared to three in standing. In standing trunk angle showed five out of seven mostly medium correlations with other regions compared to four out of seven in usual sitting. The low and different correlations suggest a large between-subject variability in sagittal spinal posture, without the existence of any optimal sagittal posture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Stand Up Straight: Posture for Singers.

    ERIC Educational Resources Information Center

    Gauthier, Delores R.

    2002-01-01

    Focuses on the importance of posture in music-making. Provides information on the importance of posture and the different types of posture stances to help students work toward better posture. Includes information on using kinesthetic experiences to help students improve their posture. (CMK)

  10. Evaluation of forward head posture in sitting and standing positions.

    PubMed

    Shaghayegh Fard, B; Ahmadi, Amir; Maroufi, N; Sarrafzadeh, J

    2016-11-01

    Head postural assessment is part of the orthopaedic physical examination process and could help to identify faulty head postures. One of the most common faulty postures of the craniocervical region is the forward head posture (FHP). There are several methods to evaluate FHP but it is not clear which method is more precise. The aim of this study was to compare the craniovertebral angle (CVA) between a FHP and a healthy group in sitting and standing positions. Twenty-five subjects with FHP (22.9 ± 2 years) and 25 normal subjects (21.9 ± 5 years) participated in this case-control study. Photography of the sagittal view was done in standing and relaxed sitting postures to determine the amount of the FHP. The results of independent t test showed a significant difference in the CVA between the FHP and healthy groups (P < 0.001). The result of paired t test showed a significant difference between CVA in standing and sitting postures for both groups (P < 0.001). Furthermore, the BMI had a significant negative correlation with CVA in standing position (P < 0.01). Our results indicated that the CVA was increased in the sitting posture compared to the standing posture and introduced the standing posture as a more sensitive posture to evaluate the FHP.

  11. Postural orientation and standing postural alignment in ambulant children with bilateral cerebral palsy.

    PubMed

    Domagalska-Szopa, Małgorzata; Szopa, Andrzej

    2017-08-16

    Standing postural alignment in children with cerebral palsy is usually altered by central postural control disorders. The primary aim of this study is to describe body alignment in a quiet standing position in ambulatory children with bilateral cerebral palsy compared with children with typical development. Fifty-eight children with bilateral cerebral palsy (aged 7-13years) and 45 age-matched children with typical development underwent a surface topography examination based on Moiré topography and were classified according to their sagittal postural profiles. The following eight grouping variables were extracted using a data reduction technique: angle of trunk inclination, pelvic tilt, and lordosis, the difference between kyphosis and lordosis, angle of vertebral lateral curvature, shoulder inclination, and shoulder and pelvic rotation. According to the cluster analysis results, 25% of the participants were classified into Cluster 1, 9% into Cluster 2, 49% in Cluster 3, and 17% in Cluster 4. Three different postural patterns emerged in accordance with the sagittal postural profiles in children with bilateral cerebral palsy and were defined as follows: 1) a lordotic postural pattern corresponding to forward-leaning posture; 2) a swayback postural pattern corresponding to backward-leaning posture; and 3) a balanced postural pattern corresponding to balanced posture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 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

    ERIC Educational Resources Information Center

    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…

  13. 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

    ERIC Educational Resources Information Center

    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…

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

    PubMed

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

    2015-03-01

    The purpose of the present study was to investigate the dynamic postural control of children with Down syndrome (DS). Specifically, we compared postural control and goal-directed reaching performance between children with DS and typically developing children during standing reach. Standing reach performance was analyzed in three main phases using the kinematic and kinetic data collected from a force plate and a motion capture system. Fourteen children with DS, age and gender matched with fourteen typically developing children, were recruited for this study. The results showed that the demand of the standing reach task affected both dynamic postural control and reaching performance in children with DS, especially in the condition of beyond arm's length reaching. More postural adjustment strategies were recruited when reaching distance was beyond arm's length. Children with DS tended to use inefficient and conservative strategies for postural stability and reaching. That is, children with DS perform standing reach with increased reaction and execution time and decreased amplitudes of center of pressure displacements. Standing reach resembled functional balance that is required in daily activities. It is suggested to be considered as a part of strength and balance training program with graded task difficulty. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Posture and performance: sitting vs. standing for security screening.

    PubMed

    Drury, C G; Hsiao, Y L; Joseph, C; Joshi, S; Lapp, J; Pennathur, P R

    2008-03-01

    A classification of the literature on the effects of workplace posture on performance of different mental tasks showed few consistent patterns. A parallel classification of the complementary effect of performance on postural variables gave similar results. Because of a lack of data for signal detection tasks, an experiment was performed using 12 experienced security operators performing an X-ray baggage-screening task with three different workplace arrangements. The current workplace, sitting on a high chair viewing a screen placed on top of the X-ray machine, was compared to a standing workplace and a conventional desk-sitting workplace. No performance effects of workplace posture were found, although the experiment was able to measure performance effects of learning and body part discomfort effects of workplace posture. There are implications for the classification of posture and performance and for the justification of ergonomics improvements based on performance increases.

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

    PubMed

    Szopa, Andrzej; Domagalska-Szopa, Małgorzata

    2015-04-01

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

  17. The Control of Posture in Newly Standing Infants is Task Dependent

    ERIC Educational Resources Information Center

    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…

  18. The Control of Posture in Newly Standing Infants is Task Dependent

    ERIC Educational Resources Information Center

    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…

  19. Relationship between morphologic somatotypes and standing posture equilibrium.

    PubMed

    Allard, P; Nault, M L; Hinse, S; LeBlanc, R; Labelle, H

    2001-01-01

    Previous studies have identified height and weight as important factors affecting quiet standing stability but studies have not addressed body morphology as a global factor. Using anthropometric measurements, the morphologic somatotypes were defined in terms of body composition and structure. The aim of this study was to test the hypothesis that morphologic somatotypes were related to standing posture equilibrium in able-bodied girls. A total of 43 able-bodied girls having a mean age of 13.8 +/- 2.2 years participated in this study. Somatotype measurements were taken to determine their endomorphic, mesomorphic or ectomorphic components. Then, subjects were asked to stand still on a force platform for 64 s with their eyes opened, feet about 23 cm apart and arms aligned with the trunk. Afterwards, subjects were grouped based on the highest value of their somatotype component. There was no statistical difference in age, height and weight among the groups. The surface area of an ellipse delineated by the displacement of the centre of pressure (COP) was statistically larger (236.9 +/- 134.3 mm2) for the ectomorphs than for the endomorphs 137.7 +/- 71.4 mm2). The minor axis was longer (8.1 +/- 2.9 mm) for the ectomorphs than for the endomorphs (5.7 +/- 2.2 mm). The decrease in standing posture stability of the ectomorphic group was attributed to a relatively low muscle component, a high height weight ratio and an elevated position of the body centre of mass in this population of girls. Somatotypes should be considered when assessing standing posture in both able-bodied subjects and patients.

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

    PubMed

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

    2016-01-01

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

  1. Implications of high-heeled shoes on body posture of adolescents.

    PubMed

    Silva, Anniele Martins; de Siqueira, Gisela Rocha; da Silva, Giselia Alves P

    2013-06-01

    To review studies regarding effects of high-heeled shoes on body posture of adolescents. The research was conducted in the Scopus, SciELO and PubMed databases between 1980 and 2011, searching for articles written in English and Portuguese with the following key-words: "posture", "center of gravity", and "high-heeled shoes". Among 55 retrieved articles, 20 were analyzed regarding posture of the spine and lower limbs, the center of gravity, and the effects of high-heeled shoes in the musculoskeletal system in adolescents. Frequent use of high-heeled shoes leads to modification of the gravity center and body balance, which can lead to changes in the alignment of body segments. This has a negative impact on motor development of adolescents. In this phase, it is necessary to keep the posture in order to maintain the physiological growth and development of the musculoskeletal system. High-heeled shoes in adolescents can lead to the development of postural disorders, among which stands out the forward head posture, lumbar hyperlordosis, pelvic anteversion, and knee valgus. The height and width of the heels are characteristics that exert most influence in the emergence of postural changes and body imbalance.

  2. Standing Postural Control in Individuals with Autism Spectrum Disorder: Systematic Review and Meta-Analysis

    ERIC Educational Resources Information Center

    Lim, Yi Huey; Partridge, Katie; Girdler, Sonya; Morris, Susan L.

    2017-01-01

    Impairments in postural control affect the development of motor and social skills in individuals with autism spectrum disorder (ASD). This review compared the effect of different sensory conditions on static standing postural control between ASD and neurotypical individuals. Results from 19 studies indicated a large difference in postural control…

  3. The effect of standing interventions on acute low-back postures and muscle activation patterns.

    PubMed

    Fewster, Kayla M; Gallagher, Kaitlin M; Callaghan, Jack P

    2017-01-01

    Occupations requiring prolonged periods of constrained standing are associated with the development of low back pain (LBP). Many workplaces use improvised standing aids aimed to reduce LBP. Unfortunately, there is little scientific evidence to support the use of such standing interventions in effectively reducing LBP. To assess some commonly implemented standing interventions, thirty-one participants stood in four different standing positions (Level Ground (control), Sloped, Elevated, and Staggered) for 5 min each. The use of an elevated surface changed the lumbar spine posture of participants such that participants stood in a more flexed lumbar spine posture. This change in lumbar spine posture may be an indication that the elevated standing aid intervention can positively impact lumbar spine posture in standing pain developers and potentially reduce LBP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Postural support by a standing aid alleviating subjective discomfort among cooks in a forward-bent posture during food preparation.

    PubMed

    Iwakiri, Kazuyuki; Kunisue, Reiko; Sotoyama, Midori; Udo, Hiroshi

    2008-01-01

    In this study, we evaluated the effects on subjective discomfort among cooks during food preparation through use of a standing aid that we developed to alleviate the workload on the low back in the forward-bent posture. Twelve female cooks who worked in a kitchen in a nursing home were asked to prepare foods in 2 working postures: (a) supported by the standing aid (Aid) and (b) without the aid (No aid). They were instructed to evaluate discomfort in 13-body regions during food preparation and the degree of fatigue at the day's end and to enter their ratings after the end of the workday. Since a significant correlation was observed between body height and the improvement effect of discomfort through use of the standing aid, cooks were divided into two groups according to the height, and ratings were analyzed in each group. Among the tall cooks, subjective discomfort in the low back and the front and back of thighs was significantly less with the Aid posture than with the No aid posture. However, in short cooks these values tended to increase in the Aid posture compared with the No aid posture. The results suggest that the standing aid was effective in alleviating tall cooks' workload on the low back in the forward-bent posture.

  5. The effects of "raked" stages on standing posture in dancers.

    PubMed

    Pappas, Evangelos; Hagins, Marshall

    2008-01-01

    Professional dancers performing on "raked" (inclined) stages sustain more injuries than dancers who perform on flat stages. However, the effects of raked stages on standing posture have not been examined. Eight professional dancers stood for four seconds on flat and inclined surfaces while trunk and lower extremity angle data were collected in a controlled laboratory environment. Twelve separate ANOVA procedures were used to evaluate the effect of floor (flat vs. inclined) on kinematic variables. Dancers stood with 3.3 degrees less dorsiflexion in the posterior incline and 4.7 degrees more dorsiflexion in the anterior incline (p < .001). They also stood with increased pronation: 2.1 degrees in the posterior (p = .009), 4.10 degrees in the anterior (p = .006), and 5.20 degrees in the lateral condition (p < .001). With regard to hip abduction, the subjects demonstrated 2.90 degrees more in the medial condition and 2.70 degrees less in the lateral condition (p = .001). External hip rotation was 3.30 degrees higher for the medial (p = .027) and 5.77 degree slower in the lateral condition (p = .002). Thus, the findings of the present study demonstrate that there are significant hip and ankle angle joint differences between standing on flat and inclined surfaces. Future research should investigate the relationship of these biomechanical differences to overuse injuries.

  6. Does increased muscular tension along the torso impair postural equilibrium in a standing posture?

    PubMed

    Hamaoui, Alain; Friant, Yola; Le Bozec, Serge

    2011-10-01

    This paper focused on the relationship between active muscular tension along the torso and postural equilibrium while standing. Eleven healthy male subjects underwent a posturographic examination associated with a bimanual compression of a dynamometric bar, which was used to set the torso muscular activity at three different levels (0MVC, 20MVC, 40MVC). Electromyographic pre-tests identified the main superficial muscles of the compressive load as: pectoralis major, latissimus dorsi, thoracic and lumbar erector spinae. Kinematics of the chest wall was recorded by means of two sensing belts, in order to assess the respiratory component of the center of pressure (CP) signal. The analysis of time-domain stabilometric parameters showed that CP displacements were larger and faster in 40MVC that in 20MVC, with no variation between 0MVC and 20MVC. The respiratory component of the CP signal was not sensitive to the compressive load. It was concluded that increased muscular tension along the torso is likely to disturb postural equilibrium, but only when it exceeds a given level.

  7. Investigation of postural hypotension due to static prolonged standing in female workers.

    PubMed

    Kabe, Isamu; Tsuruoka, Hiroko; Tokujitani, Yoko; Endo, Yuichi; Furusawa, Mami; Takebayashi, Toru

    2007-07-01

    The "Just-in-Time system" improves productivity and efficiency through cost reduction while it makes workers work in a standing posture. The aim of this study was to investigate the prevalence of postural hypotension in females during prolonged standing work, and to discuss preventive methods. Twelve female static standing workers (mean age+/-standard deviation; 32+/-14 yr old), 6 male static standing workers (30+/-4 yr old), 10 female walking workers (27+/-7 yr old) and 9 female desk workers (31+/-5 yr old) in a certain telecommunications equipment manufacturing factory agreed to participate in this study. All participants received an interview with an occupational physician, and performed the standing up test before working and ambulatory blood pressure monitoring (ABPM) while working. Although the blood pressure of the standing up test did not differ among the groups, mean pulse rates on standing up significantly increased in every group. Hypotension rates in the female standing workers' group by ABPM were 9 persons of 12 participants (75%) for systolic blood pressure (SBP), and were 11 persons of 12 participants (92%) for diastolic blood pressure (DBP). There were significantly higher than those in the female desk workers' group, none of 9 participants (0%) for SBP and 2 of 9 participants (22%) for DBP. The hypotension rates both male standing and female walking worker groups did not differ. Because all 8 workers who were found to have postural hypotension by the standing up test had decreased SBP and/or DBP by ABPM, it is suggested that persons at high risk of postural hypotension during standing work could be screened by the standing up test. The mechanism of postural hypotension may be a decrease of venous return due to leg swelling, and neurocardiogenic or vasovagal response. Preventing the congestion of the lower limbs by walking, managing standing time and wearing elastic hose to keep the amount of the venous return could prevent postural hypotension

  8. Effects of noise on postural stability when in the standing position.

    PubMed

    Azevedo, Rui; Teixeira, Nuno; Abade, Eduardo; Carvalho, Alberto

    2016-04-06

    Loss of postural stability may result in postural imbalance and can increase the risk of slips and falls in the workplace. This study intended to provide new insight into the effects of noise on postural stability when in the standing position. Twenty healthy subjects voluntarily participated in this study. Their postural stability was analysed using a baropodometry platform under 4 different sets of conditions: i) standing position, without any noise and without wearing ear protectors; ii) standing position, without any noise and wearing ear protectors; iii) standing position, with noise and without wearing ear protectors; iv) standing position, with noise and wearing ear protectors. The results showed that noise at different sound frequencies (400, 2000, 4000 and 8000 Hz) at a level of 95-100 dBA did not affect the participants' postural stability when in the standing position. No significant differences were found in postural balance when participants were exposed to sound with or without ear protectors. Short duration, sensory inputs (i.e. vision) and the absence of physical workloads appear to facilitate postural stability.

  9. Postural and cortical responses following visual occlusion in standing and sitting tasks.

    PubMed

    Goh, Kwang Leng; Morris, Susan; Lee, Wee Lih; Ring, Alexander; Tan, Tele

    2017-06-01

    Perturbation-evoked responses (PERs) to a physical perturbation of postural stability have been detected using electroencephalography (EEG). Components of these responses are hypothesized to demonstrate the detection (P1) and evaluation (N1) of postural instability. Despite the important contribution of the visual system to postural control, PERs to a visual perturbation of posture have yet to be reported. Ten healthy young adults were exposed to unpredictable visual occlusion mediated through liquid crystal glasses under two conditions of postural demand: quiet standing and quiet sitting. The participants' PERs and postural responses were recorded and differences between conditions assessed using Wilcoxon signed-rank tests. In response to unpredictable visual occlusion, both P1 and N1 components of the PER were observed in both postural conditions. The amplitude of the P1 response remained consistent between postural conditions ([Formula: see text], [Formula: see text]), whereas N1 amplitude and postural responses were significantly smaller in the sitting condition ([Formula: see text], [Formula: see text]). This is the first study to demonstrate cortical responses to visual perturbation of posture. The responses to postural perturbation by sudden visual occlusion are similar in nature to that seen in relation to a physical perturbation. In addition, the amplitude of the N1 response is not only consistent with the relative magnitude of the perturbation, but also the underlying postural set, with a larger N1 seen in standing relative to sitting. The study informs the relative importance of vision to postural stability, postural set and provides a protocol to objectively assess sensory-based postural disorders.

  10. Assisting people with multiple disabilities actively correct abnormal standing posture with a Nintendo Wii balance board through controlling environmental stimulation.

    PubMed

    Shih, Ching-Hsiang; Shih, Ching-Tien; Chu, Chiung-Ling

    2010-01-01

    The latest researches adopted software technology turning the Nintendo Wii Balance Board into a high performance change of standing posture (CSP) detector, and assessed whether two persons with multiple disabilities would be able to control environmental stimulation using body swing (changing standing posture). This study extends Wii Balance Board functionality for standing posture correction (i.e., actively adjust abnormal standing posture) to assessed whether two persons with multiple disabilities would be able to actively correct their standing posture by controlling their favorite stimulation on/off using a Wii Balance Board with a newly developed standing posture correcting program (SPCP). The study was performed according to an ABAB design, in which A represented baseline and B represented intervention phases. Data showed that both participants significantly increased time duration of maintaining correct standing posture (TDMCSP) to activate the control system to produce environmental stimulation during the intervention phases. Practical and developmental implications of the findings were discussed.

  11. Decreasing Internal Focus of Attention Improves Postural Control during Quiet Standing in Young Healthy Adults

    ERIC Educational Resources Information Center

    Nafati, Gilel; Vuillerme, Nicolas

    2011-01-01

    This experiment was designed to investigate whether and how decreasing the amount of attentional focus invested in postural control could affect bipedal postural control. Twelve participants were asked to stand upright as immobile as possible on a force platform in one control condition and one cognitive condition. In the latter condition, they…

  12. Decreasing Internal Focus of Attention Improves Postural Control during Quiet Standing in Young Healthy Adults

    ERIC Educational Resources Information Center

    Nafati, Gilel; Vuillerme, Nicolas

    2011-01-01

    This experiment was designed to investigate whether and how decreasing the amount of attentional focus invested in postural control could affect bipedal postural control. Twelve participants were asked to stand upright as immobile as possible on a force platform in one control condition and one cognitive condition. In the latter condition, they…

  13. Effect of masticating chewing gum on postural stability during upright standing.

    PubMed

    Kushiro, Keisuke; Goto, Fumiyuki

    2011-01-07

    The purpose of this study was to investigate the effect of masticating chewing gum on postural stability during upright standing. To address this issue, 12 healthy subjects performed quiet standing on a force platform for the posturography study. The subjects were instructed to stand as stable as possible on the force platform in order to record the trajectory of the center-of-pressure (COP). After measuring the postural sway in the initial condition (pre-condition), the subjects were asked to stand while masticating chewing gum (gum-condition). Following the gum-condition, quiet standing without mastication was evaluated (post-condition) to ensure the effect of masticating chewing gum on postural stability. The trajectory and velocity of the COP were analyzed for each condition. We found that the postural stability tended to enhance during mastication of chewing gum. The rectangle area of the COP trajectory significantly diminished in the gum-condition and significantly enlarged in the post-condition. A similar effect was observed in the maximum velocity and standard deviation (SD) of the fore-aft amplitude of the COP trajectory. The values were significantly smaller in the gum-condition compared to those in the post-condition. These findings suggest that mastication of chewing gum affects the postural control by enhancing the postural stability during upright standing. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  14. A radiographic assessment of lumbar spine posture in four different upright standing positions.

    PubMed

    Gallagher, Kaitlin M; Sehl, Michael; Callaghan, Jack P

    2016-08-01

    Approximately 50% of a sample population will develop prolonged standing induced low back pain. The cause of this pain may be due to their lumbar spine posture. The purpose of this study was to investigate differences in lumbar posture between 17 participants categorized as a pain or non-pain developers during level ground standing. A secondary purpose was to evaluate the influence of two standing aids (an elevated surface to act as a foot rest and declined sloped surface) on lumbopelvic posture. Four sagittal plane radiographs were taken: a normal standing position on level ground, when using an elevated foot rest, using a declined sloped surface, and maximum lumbar spine extension as a reference posture. Lumbosacral lordosis, total lumbar lordosis, and L1/L2 and L5/S1 intervertebral joint angles were measured on each radiograph. There was a significant difference between the lumbosacral lordosis angle and L5/S1 angles in upright versus maximum extension; however, this was independent of pain group. The elevated surface was most effective at causing lumbosacral spine flexion. Potentially successful postures for eliminating low back pain during prolonged standing mainly influence the lower lumbar lordosis. Future work should assess the influence of hip posture on low back pain development during standing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Posture in dentists: Sitting vs. standing positions during dentistry work--An EMG study.

    PubMed

    Pejcić, Natasa; Jovicić, Milica Đurić; Miljković, Nadica; Popović, Dejan B; Petrović, Vanja

    2016-01-01

    Adequate working posture is important for overall health. Inappropriate posture may increase fatigue, decrease efficiency, and eventually lead to injuries. The purpose was to examine posture positions used during dentistry work. In order to quantify different posture positions, we recorded muscle activity and positions of body segments. The position (inclination) data of the back was used to assess two postures: sitting and standing during standard dental interventions. During standard interventions, whether sitting or standing, a tilt of less than 20 degrees was most prevalent in the forward and lateral flexion directions. Amplitude of electromyography signals corresponding to the level of muscle activity were higher in sitting compared with the electromyography in standing position for all muscle groups on the left and right side of the body. Significant difference between muscle activity in two working postures was evident in splenius capitis muscle on the left (p = 0.032), on the right side of the body (p = 0.049) and in muscle activity of mastoid muscle on the left side (p = 0.029). These findings show that risk for increased fatigue and possible injures can be reduced by combining the sitting and standing occupational postures.

  16. Classification of sagittal thoraco-lumbo-pelvic alignment of the adolescent spine in standing and its relationship to low back pain.

    PubMed

    Smith, Anne; O'Sullivan, Peter; Straker, Leon

    2008-09-01

    A prospective study of the sagittal standing posture of 766 adolescents. To determine whether posture subgroups based on photographic assessment are similar to those used clinically and to previous, radiographically determined subgroups of sagittal standing posture, and whether identified subgroups are associated with measures of spinal pain. Relatively little research has been performed toward a classification of subjects according to sagittal spinal alignment. Clinical descriptions of different standing posture classifications have been reported, and recently confirmed in a radiographic study. There is limited epidemiological data available to support the belief that specific standing postures are associated with back pain, despite plausible mechanisms. As posture assessment using radiographic methods are limited in large population studies, successful characterization of posture using 2-dimensional photographic images will enable epidemiological research of the association between posture types and spinal pain. METHODS.: Three angular measures of thoraco-lumbo-pelvic alignment were calculated from lateral standing photographs of subjects with retro-reflective markers placed on bony landmarks. Subgroups of sagittal thoracolumbar posture were determined by cluster analysis of these 3 angular measures. Back pain experience was assessed by questionnaire. The associations between posture subgroups and spinal pain variables were evaluated using logistic regression. Postural subtypes identified by cluster analysis closely corresponded to those subtypes identified previously by analysis of radiographic spinal images in adults and to those described clinically. Significant associations between posture subgroups and weight, height, body mass index, and gender were identified. Those adolescents classified as having non-neutral postures when compared with those classified as having a neutral posture demonstrated higher odds for all measures of back pain, with 7 of 15

  17. Foot sole skin vibration perceptual thresholds are elevated in a standing posture compared to sitting.

    PubMed

    Mildren, Robyn L; Strzalkowski, Nicholas D J; Bent, Leah R

    2016-01-01

    Foot sole sensitivity is commonly assessed while individuals are seated or prone; however the primary role of foot sole cutaneous feedback is for the control of upright stance and gait. The aim of this study was to compare vibration perceptual thresholds across the foot sole between sitting and standing postures. Vibration perceptual thresholds were measured in sitting and standing postures in 18 healthy participants (8 male) using a custom vibration device. Two foot sole locations (heels and metatarsals) were tested at four vibration frequencies (3, 15, 40, and 250Hz) selected to target different cutaneous afferent populations. At each frequency, perceptual thresholds across the foot sole were significantly higher in the standing posture compared to the sitting posture; this is indicative of lower sensitivity while standing. In addition, threshold differences between the heels and metatarsals for lower frequency vibratory stimuli were more pronounced while standing, with higher thresholds observed at the heels. Our results demonstrate that standing significantly alters sensitivity across the foot sole. Therefore, conducting perceptual tests at the foot sole during stance could potentially provide more direct information about the ability of cutaneous afferents to signal tactile information in a state where this feedback can contribute to postural control. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Muscle activation and energy-requirements for varying postures in children and adolescents with cerebral palsy.

    PubMed

    Verschuren, Olaf; Peterson, Mark D; Leferink, Svenja; Darrah, Johanna

    2014-11-01

    To determine energy expenditure and muscle activity among children and adolescents with cerebral palsy (CP), across several conditions that approximate sedentary behavior, and standing. Subjects with spastic CP (n = 19; 4-20 years of age; Gross Motor Function Classification System Expanded and Revised [GMFCS-E&R] levels I-V) participated in this cohort study. Energy-expenditure and muscle activity were measured during lying supine, sitting with support, sitting without support, and standing. Energy-expenditure was measured using indirect calorimetry and expressed in metabolic equivalents (METs). Muscle activation was recorded using surface electromyography. The recorded values were calculated for every child and then averaged per posture. Mean energy expenditure was >1.5 METs during standing for all GMFCS-E&R levels. There was a nonsignificant trend for greater muscle activation for all postures with less support. Only for children classified at GMFCS-E&R level III did standing result in significantly greater muscle activation (P < .05) compared with rest. Across all GMFCS-E&R levels, children and adolescents with CP had elevated energy expenditure during standing that exceeded the sedentary threshold of 1.5 METs. Our findings suggest that changing a child's position to standing may contribute to the accumulation of light activity and reduction of long intervals of sedentary behavior. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Muscle activation and energy-requirements for varying postures in children and adolescents with cerebral palsy

    PubMed Central

    Peterson, Mark D.; Leferink, Svenja; Darrah, Johanna

    2015-01-01

    Objective To determine energy expenditure and muscle activity among children and adolescents with cerebral palsy (CP), across several conditions that approximate sedentary behavior, and standing. Study design Subjects with spastic CP (n=19; 4–20 years of age; Gross Motor Function Classification System [GMFCS] levels I to V) participated in this cohort study. Energy-expenditure and muscle activity were measured during lying supine, sitting with support, sitting without support, and standing. Energy-expenditure was measured using indirect calorimetry and expressed in metabolic equivalents (METs). Muscle activation was recorded using surface electromyography. The recorded values were calculated for every child and then averaged per posture. Results Mean energy expenditure was >1.5 METs during standing for all GMFCS levels. There was a non-significant trend for greater muscle activation for all postures with less support. Only for children classified at GMFCS level III standing resulted in significantly greater muscle activation (p<0.05) compared with rest. Conclusion Across all GMFCS levels, children and adolescents with CP had elevated energy expenditure during standing that exceeded the sedentary threshold of 1.5 METs. Our findings suggest that changing a child’s position to standing may contribute to the accumulation of light activity and reduction of long intervals of sedentary behavior. PMID:25151195

  20. "Stand up straight": notes toward a history of posture.

    PubMed

    Gilman, Sander L

    2014-03-01

    The essay presents a set of interlinked claims about posture in modern culture. Over the past two centuries it has come to define a wide range of assumptions in the West from what makes human beings human (from Lamarck to Darwin and beyond) to the efficacy of the body in warfare (from Dutch drill manuals in the 17th century to German military medical studies of soldiers in the 19th century). Dance and sport both are forms of posture training in terms of their own claims. Posture separates 'primitive' from 'advanced' peoples and the 'ill' from the 'healthy.' Indeed an entire medical sub-specialty developed in which gymnastics defined and recuperated the body. But all of these claims were also part of a Western attempt to use posture (and the means of altering it) as the litmus test for the healthy modern body of the perfect citizen. Focusing on the centrality of posture in two oddly linked moments of modern thought--modern Zionist thought and Nationalism in early 20th century China--in terms of bodily reform, we show how "posture" brings all of the earlier debates together to reform the body.

  1. Posture switching for prolonging functional electrical stimulation standing in paraplegic patients.

    PubMed

    Krajl, A; Bajd, T; Turk, R; Benko, H

    1986-08-01

    The presently employed posture for Functional Electrical Stimulation (FES) assisted standing in spinal cord injury (SCI) patients utilises the active locking of knee joints by tetanically stimulating the quadriceps muscle. The hip joints are in hyperextension and the ankle joints remain free. The upper limbs are used for balancing. This posture requires minimal corrective forces exerted by the hands, the weight is transferred across the legs, while very limited forward-backward sway is permitted. Knee jack-knifing may occur in the instance when the gravity knee bending moment exceeds the moment generated by the quadriceps muscle. Because of these effects and fatiguing of the M. quadriceps the standing time is short, lasting from several minutes up to an hour, depending on the condition of the patient's muscles. Cyclical FES with a duty cycle of 10-20 seconds (on/off) fatigues muscle considerably less. The use of different postures for standing requiring activation of different muscles permits the application of cyclical FES. The cyclic FES results in prolonging standing times by a factor of two to five. Utilising this improvement some patients can stand for up to five hours at a time. This functional achievement is comparable to the standing time of a normal man. The incorporation of the principle of posture switching also prolongs standing in patients with weak muscles, because of the possibility of cyclical coactivation of different synergistic muscle assemblies. It is shown that posture switching can be carried out automatically and that patients adapt quickly to it. In addition using co-contraction of two or three muscles with posture switching does further expand the range of suitable patients and improves standing with an increased permissible range of body sway. Also, the FES antigravity action obtained raises hopes for substantially improving FES induced reciprocal gait.

  2. Balance training improves postural balance, gait, and functional strength in adolescents with intellectual disabilities: Single-blinded, randomized clinical trial.

    PubMed

    Lee, Kyeongjin; Lee, Myungmo; Song, Changho

    2016-07-01

    Adolescents with intellectual disabilities often present with problems of balance and mobility. Balance training is an important component of physical activity interventions, with growing evidence that it can be beneficial for people with intellectual disabilities. The aim of this study was to investigate the effect of balance training on postural balance, gait, and functional strength in adolescents with intellectual disabilities. Thirty-two adolescents with intellectual disabilities aged 14-19 years were randomly assigned either to a balance training group (n = 15) or a control group (n = 16). Subjects in the balance training group underwent balance training for 40 min per day, two times a week, for 8 weeks. All subjects were assessed with posture sway and the one-leg stance test for postural balance; the timed up-and-go test and 10-m walk test for gait; and sit to stand test for functional strength. Postural balance and functional strength showed significant improvements in the balance training group (p < 0.05) as compared to baseline; however, postural balance and muscle strength showed no significant improvements in the control group. Further, postural balance and functional strength significantly improved in the balance training group compared with those in the control group. Balance training for adolescents with intellectual disabilities might be beneficial for improving postural balance and functional strength. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Human body area factors for radiation exchange analysis: standing and walking postures.

    PubMed

    Park, Sookuk; Tuller, Stanton E

    2011-09-01

    Effective radiation area factors (f (eff)) and projected area factors (f (p)) of unclothed Caucasians' standing and walking postures used in estimating human radiation exchange with the surrounding environment were determined from a sample of adults in Canada. Several three-dimensional (3D) computer body models were created for standing and walking postures. Only small differences in f (eff) and f (p) values for standing posture were found between gender (male or female) and body type (normal- or over-weight). Differences between this study and previous studies were much larger: ≤0.173 in f (p) and ≤0.101 in f (eff). Directionless f (p) values for walking posture also had only minor differences between genders and positions in a stride. However, the differences of mean directional f (p) values of the positions dependent on azimuth angles were large enough, ≤0.072, to create important differences in modeled radiation receipt. Differences in f (eff) values were small: 0.02 between the normal-weight male and female models and up to 0.033 between positions in a stride. Variations of directional f (p) values depending on solar altitudes for walking posture were narrower than those for standing posture. When both standing and walking postures are considered, the mean f (eff) value, 0.836, of standing (0.826) and walking (0.846) could be used. However, f (p) values should be selected carefully because differences between directional and directionless f (p) values were large enough that they could influence the estimated level of human thermal sensation.

  4. Parkinsonian deficits in context-dependent regulation of standing postural control.

    PubMed

    Brown, Lesley A; Doan, Jon B; Whishaw, Ian Q; Suchowersky, Oksana

    2007-05-18

    This study explored whether patients with Parkinson's disease alter the regulation of upright standing according to constraints imposed by the environmental context. The provision of context-dependent adaptations was inferred from the presence of adjustments to standing postural control that would serve to reduce fall risk when balance was challenged by a threatening environmental context. Participants were asked to stand as still as possible in two environmental context conditions that differed in the level of imposed postural threat: LOW threat and HIGH threat. Eight levodopa dependent patients with Parkinson's disease (PD) and eight age-matched control subjects (CTRL) provided the subject sample. PD patients were tested following a 12-h withdrawal of anti-Parkinsonian medications and approximately 1h post-medication. The CTRL group showed altered postural control in the HIGH threat condition, in a manner that was indicative of appropriate context-dependent regulation of standing. PD patients, in the non-medicated or medicated states, did not modify stance regulation when the environmental context heightened postural threat. Our results extend the current understanding of Parkinsonian deficits in the context-dependent regulation of postural control to include upright standing.

  5. Rasterstereographic analysis of axial back surface rotation in standing versus forward bending posture in idiopathic scoliosis.

    PubMed

    Hackenberg, Lars; Hierholzer, Eberhard; Bullmann, Viola; Liljenqvist, Ulf; Götze, Christian

    2006-07-01

    The forward bending test according to Adams and rib hump quantification by scoliometer are common clinical examination techniques in idiopathic scoliosis, although precise data about the change of axial surface rotation in forward bending posture are not available. In a pilot study the influence of leg length inequalities on the back shape of five normal subjects was clarified. Then 91 patients with idiopathic scoliosis with Cobb-angles between 20 degrees and 82 degrees were examined by rasterstereography, a 3D back surface analysis system. The axial back surface rotation in standing posture was compared with that in forward bending posture and additionally with a scoliometer measurement in forward bending posture. The changes of back shape in forward bending posture were correlated with the Cobb-angle, the level of the apex of the scoliotic primary curve and the age of the patient. Averaged over all patients, the back surface rotation amplitude increased from 23.1 degrees in standing to 26.3 degrees in forward bending posture. The standard deviation of this difference was high (6.1 degrees ). The correlation of back surface rotation amplitude in standing with that in forward bending posture was poor (R (2)=0.41) as was the correlation of back surface rotation in standing posture with the scoliometer in forward bending posture measured rotation (R (2)=0.35). No significant correlation could be found between the change of back shape in forward bending and the degree of deformity (R (2)=0.07), likewise no correlation with the height of the apex of the scoliosis (R (2)=0.005) and the age of the patient (R (2)=0.001). Before forward bending test leg length inequalities have to be compensated accurately. Compared to the standing posture, forward bending changes back surface rotation. However, this change varies greatly between patients, and is independent of the type and degree of scoliosis. Furthermore remarkable differences were found between scoliometer measurement

  6. Not just standing there: the use of postural coordination to aid visual tasks.

    PubMed

    Smart, L James; Mobley, Brandy S; Otten, Edward W; Smith, Dean L; Amin, Maryse R

    2004-04-01

    Postural control is an integral part of all physical behavior. Recent research has indicated that postural control functions in a manner that facilitates other higher order (suprapostural) tasks. These studies, while showing that postural sway is modulated in a task specific manner, have not examined the form of postural coordination that allows for the achievement of these higher behavioral goals. The current study examined the relation between visual task constraints (viewing distance), environmental constraints (changes in the surface of support), and the postural coordination employed to complete the task. Thirty-one participants were asked to perform a reading task while standing on various surfaces. Postural motion was recorded from the head, cervico-thoracic spine, sacrum (hip), and ankle. It was found that body segment coordination changed as a function of surface characteristics and task constraints. Additionally, the overall pattern of postural sway (head motion) replicated that which was found by Stoffregen et al. [J. Exp. Psychol. Human Percep. Perform. 25 (6) (1999) 1641]. These findings suggest that postural adaptation involves more than basic reduction or increase of motion; it involves the functional coordination of body segments to achieve a particular goal. The data further suggest that there is a need to examine postural control in the absence of external perturbations.

  7. Standing Postural Control in Individuals with Autism Spectrum Disorder: Systematic Review and Meta-analysis.

    PubMed

    Lim, Yi Huey; Partridge, Katie; Girdler, Sonya; Morris, Susan L

    2017-07-01

    Impairments in postural control affect the development of motor and social skills in individuals with autism spectrum disorder (ASD). This review compared the effect of different sensory conditions on static standing postural control between ASD and neurotypical individuals. Results from 19 studies indicated a large difference in postural control between groups across all sensory conditions. This review revealed sensorimotor and multiple sensory processing deficits in ASD. The tendency for individuals with ASD to be more susceptible to postural instability with use of visual information compared with somatosensory information suggests perinatal alterations in sensory development. There is further scope for studies on the use of sensory information and postural control to provide additional evidence about sensorimotor processing in ASD.

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

    PubMed

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

    2014-11-01

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

  9. Development and validation of a novel rating system for scoring standing foot posture: the Foot Posture Index.

    PubMed

    Redmond, Anthony C; Crosbie, Jack; Ouvrier, Robert A

    2006-01-01

    The limitations of clinical methods for appraising foot posture are well documented. A new measure, the Foot Posture Index is proposed, and its development and validation described. A four-phase development process was used: (i) to derive a series of candidate measures, (ii) to define an appropriate scoring system, (iii) to evaluate the validity of components and modify the instrument as appropriate, and (iv) to investigate the predictive validity of the finalised instrument relative to static and dynamic kinematic models. Methods included initial concurrent validation using Rose's Valgus Index, determination of inter-item reliability, factor analysis, and benchmarking against three dimensional kinematic models derived from electromagnetic motion tracking of the lower limb. Thirty-six candidate components were reduced to six in the final instrument. The draft version of the instrument predicted 59% of the variance in concurrent Valgus Index scores and demonstrated good inter item reliability (Cronbach's alpha = 0.83). The relevant variables from the motion tracking lower limb model predicted 58-80% of the variance in the six components retained in the final instrument. The finalised instrument predicted 64% of the variance in static standing posture, and 41% of the variance in midstance posture during normal walking. The Foot Posture Index has been subjected to thorough evaluation in the course of its development and a final version is proposed comprising six component measures that performed satisfactorily during the validation process. The Foot Posture Index assessment is quick and simple to perform and allows a multiple segment, multiple plane evaluation that offers some advantages over existing clinical measures of foot posture.

  10. The influence of initial posture on the sit-to-stand movement.

    PubMed

    Stevens, C; Bojsen-Møller, F; Soames, R W

    1989-01-01

    Head movements, ground reaction forces and electromyographic activity of selected muscles were recorded simultaneously from two subjects as they performed the sit-to-stand manouevre under a variety of conditions. The influence of initial leg posture on the magnitude of the various parameters under investigation was examined first. A preferred initial leg posture resulted in smaller magnitudes of head movement and ground reaction forces. EMG activity in some muscles, trapezius and erector spinae, decreased, while in others, quadriceps and hamstrings, it increased in the preferred leg posture. The decreases seen correlate with reductions in head movement observed. The effect of inhibiting habitual postural adjustments of the head and neck, by comparing "free" and "guided" movements was also examined. In guided movements there are significant reductions in head movement, ground reaction forces and EMG activity in trapezius, sternomastoid and erector spinae. It would appear that both initial leg posture and the abolition of habitual postural adjustment have a profound influence on the efficiency of the sit-to-stand manouevre. This preliminary study high-lights the practical importance of head posture in the diagnosis and treatment of movement disorders, as well as in movement education.

  11. [Functional characteristics of gait and standing posture in poststroke patients in residual period].

    PubMed

    Batysheva, T T; Rusina, L R; Skvortsov, D V; Boĭko, A N

    2004-01-01

    Using biomechanic method, gait and standing posture were studied in 17 stroke patients in a remote poststroke period. The locomotor system was found to have non-specific compensatory changes to optimize motor functions and reduce functional disturbances. Symptoms of the triceps surae muscle insufficiency as well as a balance deficit at standing posture and displacement of the center of pressure towards the non-affected side were characteristic of the given stage of rehabilitation stroke period that should be taken into account during the rehabilitation treatment.

  12. Postural responses accompanying Achilles tendon vibration stimulation during various phases of sit-to-stand movement.

    PubMed

    Kurokawa, Nozomi; Fujiwara, Katsuo; Kiyota, Naoe

    2013-01-01

    The aim of this study was to determine the postural response accompanying Achilles tendon vibration stimulation during various phases of the sit-to-stand movement. Twelve healthy young adults performed the sit-to-stand movement in response to an auditory signal 2 s after a first one. Vibration stimulation with a 100 Hz frequency was applied to both Achilles tendons during the following phases: (1) 10 s of sitting before standing up; (2) 10 s plus a period until the standing position was achieved; and (3) 5 s after standing. The postural response after standing was analyzed with the center of foot pressure in the anteroposterior direction. Forward-leaning responses were identified in 78.3% and 63.3% of trials under conditions 1 and 2, respectively. Backward-leaning responses were identified in 93.3% of the trials under condition 3. Response latency (+/- standard deviation) was significantly longer under conditions 1 and 2 than under condition 3 (1: 872 +/- 576, 2: 1026 +/- 542, and 3:555 +/- 322 ms; ps < 0.05). Sensory information at the standing point might be anticipated based on sensory information received while sitting. Consequently, postural response as a compensatory movement would occur via the sensory reference system within the supraspinal nervous system.

  13. Should a standing or seated reference posture be used when normalizing seated spine kinematics?

    PubMed

    Cotter, Brendan D; Nairn, Brian C; Drake, Janessa D M

    2014-07-18

    Currently in the literature there is no consensus on which procedure for normalizing seated spine kinematics is most effective. The objective of this study was to examine the changes in the range of motion (ROM) of seated posture trials when expressed as a percent of maximum standing and seated ROM. A secondary purpose was to determine whether the typical maximum planar calibration movements (flexion, lateral-bend, and axial twist) elicited the respective maximum ROM values for each spine region versus postures with specific movement instruction. Thirteen male participants completed seven different movement trials. These consisted of the maximum planar movement trials, with the remaining four postures being combinations of specific lumbar and thoracic movements. Global and relative angles for the upper-thoracic, mid-thoracic, lower-thoracic, and lumbar regions were calculated and normalized to both a seated and standing reference posture. When normalizing both global and relative angles the standing reference appears optimal for flexion, twisting and lateral bend angles in all spine regions, with the exception of relative flexion angle in the mid-thoracic region. The maximum planar movement trials captured the greatest ROM for each global angle, relative lower-thoracic angle and relative lumbar flexion angle, but did not for all other relative angles in the upper-thoracic, mid-thoracic, and lumbar regions. If future researchers can only collect one reference posture these results recommend that a standing reference posture be collected for normalizing seated spine kinematics, although a seated reference posture should be collected if examining relative flexion angles at the mid-thoracic region. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2016-12-01

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

  15. Both standing and postural threat decrease Achilles' tendon reflex inhibition from tendon electrical stimulation.

    PubMed

    Horslen, Brian C; Inglis, J Timothy; Blouin, Jean-Sébastien; Carpenter, Mark G

    2017-07-01

    Golgi tendon organs (GTOs) and associated Ib reflexes contribute to standing balance, but the potential impacts of threats to standing balance on Ib reflexes are unknown. Tendon electrical stimulation to the Achilles' tendon was used to probe changes in Ib inhibition in medial gastrocnemius with postural orientation (lying prone vs. upright standing; experiment 1) and height-induced postural threat (standing at low and high surface heights; experiment 2). Ib inhibition was reduced while participants stood upright, compared to lying prone (42.2%); and further reduced when standing in the high, compared to low, threat condition (32.4%). These experiments will impact future research because they demonstrate that tendon electrical stimulation can be used to probe Ib reflexes in muscles engaged in standing balance. These results provide novel evidence that human short-latency GTO-Ib reflexes are dependent upon both task, as evidenced by changes with postural orientation, and context, such as height-induced postural threat during standing. Golgi tendon organ Ib reflexes are thought to contribute to standing balance control, but it is unknown if they are modulated when people are exposed to a postural threat. We used a novel application of tendon electrical stimulation (TStim) to elicit Ib inhibitory reflexes in the medial gastrocnemius, while actively engaged in upright standing balance, to examine (a) how Ib reflexes to TStim are influenced by upright stance, and (b) the effects of height-induced postural threat on Ib reflexes during standing. TStim evoked short-latency (<47 ms) inhibition apparent in trigger-averaged rectified EMG, which was quantified in terms of area, duration and mean amplitude of inhibition. In order to validate the use of TStim in a standing model, TStim-Ib inhibition was compared from conditions where participants were lying prone vs. standing upright. TStim evoked Ib inhibition in both conditions; however, significant reductions in Ib

  16. Assisting People with Multiple Disabilities Actively Correct Abnormal Standing Posture with a Nintendo Wii Balance Board through Controlling Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang; Shih, Ching-Tien; Chu, Chiung-Ling

    2010-01-01

    The latest researches adopted software technology turning the Nintendo Wii Balance Board into a high performance change of standing posture (CSP) detector, and assessed whether two persons with multiple disabilities would be able to control environmental stimulation using body swing (changing standing posture). This study extends Wii Balance Board…

  17. Relation between postural sway magnitude and metabolic energy cost during upright standing on a compliant surface.

    PubMed

    Houdijk, Han; Brown, Starr E; van Dieën, Jaap H

    2015-09-15

    Postural control performance is often described in terms of postural sway magnitude, assuming that lower sway magnitude reflects better performance. However, people do not typically minimize sway magnitude when performing a postural control task. Possibly, other criteria are satisfied when people select the amount of sway they do. Minimal metabolic cost has been suggested as such a criterion. The aim of this study was to experimentally test the relation between sway magnitude and metabolic cost to establish whether metabolic cost could be a potential optimization criterion in postural control. Nineteen healthy subjects engaged in two experiments in which different magnitudes of sway were evoked during upright standing on a foam surface while metabolic energy expenditure, center of pressure (CoP) excursion, and muscle activation were recorded. In one experiment, sway was manipulated by visual feedback of CoP excursion. The other experiment involved verbal instructions of standing still, natural or relaxed. In both experiments, metabolic cost changed with sway magnitude in an asymmetric parabolic fashion, with a minimum around self-selected sway magnitudes and a larger increase at small compared with large sway magnitudes. This metabolic response was paralleled by a change in tonic and phasic EMG activity in the major leg muscles. It is concluded that these results are in line with the notion that metabolic cost can be an optimization criterion used to set postural control and as such could account for the magnitude of naturally occurring postural sway in healthy individuals, although the pathway remains to be elucidated.

  18. Adolescent idiopathic scoliosis and spinal fusion do not substantially impact on postural balance.

    PubMed

    Schimmel, Janneke Jp; Groen, Brenda E; Weerdesteyn, Vivian; de Kleuver, Marinus

    2015-01-01

    The spinal curvature in patients with Adolescent Idiopathic Scoliosis (AIS) causes an asymmetry of upper body postural alignment, which might affect postural balance. However, the currently available studies on balance in AIS patients are not consistent. Furthermore, it is not known whether potential deficits are similar between patients with single and double curves. Finally, the effects of a corrective posterior spinal fusion on postural balance have not yet been well established. Postural balance was tested on a force plate, in 26 female subjects with AIS (12-18 years old; preoperative Cobb-angle: 42-71°; single curve n = 18, double curve n = 6) preoperatively, at 3 months and 1 year postoperatively. We also conducted a balance assessment in 18 healthy age-matched female subjects. Subjects were tested during quiet double-leg standing in four conditions (eyes open/closed; foam/solid surface), while standing on one leg, while performing a dynamic balance (weight shifting) task and while performing a reaching task in four directions. AIS subjects did not demonstrate greater COP velocities than controls during the double-leg standing tasks. In the reaching task, however, they achieved smaller COP displacements than healthy controls, except in the anterior direction. AIS patients with double curves had significantly greater COP velocities in all test conditions compared to those with a single curve (p < 0.05). For the AIS group, a slight increase in COP velocities was observed in the foam eyes closed and right leg standing condition at 3 months post surgery. At 1-year post surgery, however, there were no significant differences in any of the outcome measures compared to the pre-surgery assessment, irrespective of the curve type. Postural balance in AIS patients scheduled for surgery was similar to healthy age matched controls, except for a poorer reaching capacity. The latter finding may be related to their reduced range of motion of the spine

  19. Influence of prolonged wearing of unstable shoes on upright standing postural control.

    PubMed

    Sousa, Andreia S P; Macedo, Rui; Santos, Rubim; Sousa, Filipa; Silva, Andreia; Tavares, João Manuel R S

    2016-02-01

    To study the influence of prolonged wearing of unstable shoes on standing postural control in prolonged standing workers. The participants were divided into two groups: one wore unstable shoes while the other wore conventional shoes for 8weeks. Stabilometry parameters related to centre of pressure (CoP), rambling (RM) and trembling (TR) as well as the total agonist/antagonist muscle activity, antagonist co-activation and reciprocal activation were evaluated during upright standing, before and after the 8weeks period. In both moments, the subjects were evaluated wearing the unstable shoes and in barefoot. The unstable shoe condition presented increased CoP displacement related variables and decreased co-activation command compared to barefoot before and after the intervention. The prolonged wearing of unstable shoes led to: (1) reduction of medial-lateral CoP root mean square and area; (2) decreased anteroposterior RM displacement; (3) increased anteroposterior RM mean velocity and mediolateral RM displacement; (4) decreased anteroposterior TR RMS; and (5) increased thigh antagonist co-activation in the unstable shoe condition. The unstable shoe condition is associated to a higher destabilising effect that leads to a selection of more efficient and accurate postural commands compared to barefoot. Prolonged wearing of unstable shoes provides increased effectiveness and performance of the postural control system, while wearing of unstable shoes in upright standing, that are reflected by changes in CoP related variables and by a reorganisation of postural control commands. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Organization of Functional Postural Responses Following Perturbations in Multiple Directions in Elderly Fallers Standing Quietly

    ERIC Educational Resources Information Center

    Matjacic, Zlatko; Sok, David; Jakovljevic, Miroljub; Cikajlo, Imre

    2013-01-01

    The objective of the study was to assess functional postural responses by analyzing the center-of-pressure trajectories resulting from perturbations delivered in multiple directions to elderly fallers. Ten elderly individuals were standing quietly on two force platforms while an apparatus delivered controlled perturbations at the level of pelvis…

  1. Organization of Functional Postural Responses Following Perturbations in Multiple Directions in Elderly Fallers Standing Quietly

    ERIC Educational Resources Information Center

    Matjacic, Zlatko; Sok, David; Jakovljevic, Miroljub; Cikajlo, Imre

    2013-01-01

    The objective of the study was to assess functional postural responses by analyzing the center-of-pressure trajectories resulting from perturbations delivered in multiple directions to elderly fallers. Ten elderly individuals were standing quietly on two force platforms while an apparatus delivered controlled perturbations at the level of pelvis…

  2. Bioceramic fabrics improve quiet standing posture and handstand stability in expert gymnasts.

    PubMed

    Cian, C; Gianocca, V; Barraud, P A; Guerraz, M; Bresciani, J P

    2015-10-01

    Bioceramic fabrics have been claimed to improve blood circulation, thermoregulation and muscle relaxation, thereby also improving muscular activity. Here we tested whether bioceramic fabrics have an effect on postural control and contribute to improve postural stability. In Experiment 1, we tested whether bioceramic fabrics contribute to reduce body-sway when maintaining standard standing posture. In Experiment 2, we measured the effect of bioceramic fabrics on body-sway when maintaining a more instable posture, namely a handstand hold. For both experiments, postural oscillations were measured using a force platform with four strain gauges that recorded the displacements of the center of pressure (CoP) in the horizontal plane. In half of the trials, the participants wore a full-body second skin suit containing a bioceramic layer. In the other half of the trials, they wore a 'placebo' second skin suit that had the same cut, appearance and elasticity as the bioceramic suit but did not contain the bioceramic layer. In both experiments, the surface of displacement of the CoP was significantly smaller when participants were wearing the bioceramic suit than when they were wearing the placebo suit. The results suggest that bioceramic fabrics do have an effect on postural control and improve postural stability.

  3. Diagnosing postural tachycardia syndrome: comparison of tilt testing compared with standing haemodynamics.

    PubMed

    Plash, Walker B; Diedrich, André; Biaggioni, Italo; Garland, Emily M; Paranjape, Sachin Y; Black, Bonnie K; Dupont, William D; Raj, Satish R

    2013-01-01

    POTS (postural tachycardia syndrome) is characterized by an increased heart rate (ΔHR) of ≥30 bpm (beats/min) with symptoms related to upright posture. Active stand (STAND) and passive head-up tilt (TILT) produce different physiological responses. We hypothesized these different responses would affect the ability of individuals to achieve the POTS HR increase criterion. Patients with POTS (n=15) and healthy controls (n=15) underwent 30 min of tilt and stand testing. ΔHR values were analysed at 5 min intervals. ROC (receiver operating characteristic) analysis was performed to determine optimal cut point values of ΔHR for both tilt and stand. Tilt produced larger ΔHR than stand for all 5 min intervals from 5 min (38±3 bpm compared with 33±3 bpm; P=0.03) to 30 min (51±3 bpm compared with 38±3 bpm; P<0.001). Sn (sensitivity) of the 30 bpm criterion was similar for all tests (TILT10=93%, STAND10=87%, TILT30=100%, and STAND30=93%). Sp (specificity) of the 30 bpm criterion was less at both 10 and 30 min for tilt (TILT10=40%, TILT30=20%) than stand (STAND10=67%, STAND30=53%). The optimal ΔHR to discriminate POTS at 10 min were 38 bpm (TILT) and 29 bpm (STAND), and at 30 min were 47 bpm (TILT) and 34 bpm (STAND). Orthostatic tachycardia was greater for tilt (with lower Sp for POTS diagnosis) than stand at 10 and 30 min. The 30 bpm ΔHR criterion is not suitable for 30 min tilt. Diagnosis of POTS should consider orthostatic intolerance criteria and not be based solely on orthostatic tachycardia regardless of test used.

  4. Diagnosing Postural Tachycardia Syndrome: Comparison of Tilt Test versus Standing Hemodynamics

    PubMed Central

    Plash, Walker B; Diedrich, André; Biaggioni, Italo; Garland, Emily M; Paranjape, Sachin Y; Black, Bonnie K; Dupont, William D; Raj, Satish R

    2012-01-01

    Postural tachycardia syndrome (POTS) is characterized by increased heart rate (ΔHR) of ≥30 bpm with symptoms related to upright posture. Active stand (STAND) and passive head-up tilt (TILT) produce different physiological responses. We hypothesized these different responses would affect the ability of individuals to achieve the POTS HR increase criterion. Patients with POTS (n=15) and healthy controls (n=15) underwent 30 min of TILT and STAND testing. ΔHR values were analyzed at 5 min intervals. Receiver Operating Characteristics analysis was performed to determine optimal cut point values of ΔHR for both TILT and STAND. TILT produced larger ΔHR than STAND for all 5 min intervals from 5 min (38±3 bpm vs. 33±3 bpm; P=0.03) to 30 min (51±3 bpm vs. 38±3 bpm; P<0.001). Sensitivity (Sn) of the 30 bpm criterion was similar for all tests (TILT-10=93%, STAND-10=87%, TILT30=100%, and STAND30=93%). Specificity (Sp) of the 30 bpm criterion was less at both 10 and 30 min for TILT (TILT10=40%, TILT30=20%) than STAND (STAND10=67%, STAND30=53%). The optimal ΔHR to discriminate POTS at 10 min were 38 bpm (TILT) and 29 bpm (STAND), and at 30 min were 47 bpm (TILT) and 34 bpm (STAND). Orthostatic tachycardia was greater for TILT (with lower specificity for POTS diagnosis) than STAND at 10 and 30 min. The 30 bpm ΔHR criterion is not suitable for 30 min TILT. Diagnosis of POTS should consider orthostatic intolerance criteria and not be based solely on orthostatic tachycardia regardless of test used. PMID:22931296

  5. Center-of-pressure regularity as a marker for attentional investment in postural control: a comparison between sitting and standing postures.

    PubMed

    Roerdink, Melvyn; Hlavackova, Petra; Vuillerme, Nicolas

    2011-04-01

    Postural control is a highly automatized basic activity that requires limited attentional investments. These investments have been shown to increase from balancing experts to controls, and from controls to persons with impaired postural control. Such between-subject comparisons led to a proposed direct relation between the regularity of center-of-pressure (COP) fluctuations and the amount of attention invested in posture. This study aims to expand this relation to a within-subject comparison of conditions that differ in balance demands. Specifically, more regular COP fluctuations were expected for standing than sitting, as stimulus-response reaction-time studies showed that the required attentional demands are lower for sitting than standing. COP registrations were made for fifteen healthy young adults in seated and standing postures. COP regularity was quantified with sample entropy. As expected, COP fluctuations were found to be more regular for standing than sitting, as evidenced by significantly lower sample entropy values. These findings expand the relation between COP regularity and the amount of attention invested in posture to postural tasks that vary in balance demands. An assessment of COP regularity may thus not only be instrumental in the examination of attentional investment in posture in between-subject designs, but also for different postures in within-subjects designs. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    PubMed

    Maeda, Kaoru; Fujiwara, Katsuo

    2007-01-01

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

  7. Contribution of Head Position, Standing Surface, and Vision to Postural Control in Community-Dwelling Older Adults.

    PubMed

    Pociask, Fredrick D; DiZazzo-Miller, Rosanne; Goldberg, Allon; Adamo, Diane E

    2016-01-01

    Postural control requires the integration of sensorimotor information to maintain balance and to properly position and orient the body in response to external stimuli. Age-related declines in peripheral and central sensory and motor function contribute to postural instability and falls. This study investigated the contribution of head position, standing surface, and vision on postural sway in 26 community-dwelling older adults. Participants were asked to maintain a stable posture under conditions that varied standing surface, head position, and the availability of visual information. Significant main and interaction effects were found for all three factors. Findings from this study suggest that postural sway responses require the integration of available sources of sensory information. These results have important implications for fall risks in older adults and suggest that when standing with the head extended and eyes closed, older adults may place themselves at risk for postural disequilibrium and loss of balance.

  8. Effect of Chêneau brace on postural balance in adolescent idiopathic scoliosis: a pilot study.

    PubMed

    Paolucci, T; Morone, G; Di Cesare, A; Grasso, M R; Fusco, A; Paolucci, S; Saraceni, V M; Iosa, M

    2013-10-01

    Adolescents with idiopathic scoliosis show a postural instability compared with healthy subjects. DESIGN TYPE. Case control study. Outpatient clinic of the Complex Operative Unit of Physical Medicine and Rehabilitation of Policlinico Umberto I Hospital. Thirteen patients (11 females and 2 males, mean age 13.3±1.7 years, mean Cobb angle 32±9, median Risser sign 2) and thirteen healthy adolescents (8 females and 5 males, mean age: 13.0±1.6 years) as age-matched control group were enrolled. Postural ability of the participants was assessed with stabilometry (under open eyes and closed eyes conditions), computing sway length, sway ellipse area, and sway velocities. Static and dynamic baropodometry (open eyes only) was used to measure the limb load, and to compute: walking speed, step length, step cadence and step width. The symmetry of left and right limb values was also investigated. Patient's group was characterized by significantly higher postural instability than control group (P<0.05) that decreased with brace in terms of limb load symmetry (-12% in eyes open condition), sway length (-12%), velocity in anteroposterior (-16%) and latero-lateral directions (-10%). Significant correlations were found between the changes occurred when wearing Chêneau brace on load symmetry during standing and those on symmetry of gait (R>0.5, P<0.05). Our results show slight changes in terms of posture when wearing Chêneau brace according with the severity of pathology and significantly affecting gait parameters. For these reasons, use of postural balance evaluation should be objectively used to verify the efficacy of Cheneau brace on body functioning of adolescents with idiopathic scoliosis.

  9. Effect of three different jaw positions on postural stability during standing

    PubMed Central

    Alghadir, Ahmad H.; Zafar, Hamayun; Iqbal, Zaheen A.

    2015-01-01

    Summary Studies in the literature show that jaw and neck regions are linked anatomically, biomechanically and neurologically. Voluntary clenching has been shown to improve muscle strength and performance of various motor tasks. Information from the neck sensory-motor system is reported to be important for posture. Hence it is reasonable to believe that activation of the jaw sensory-motor system has the potential to modulate posture. In a sample of 116 healthy subjects, we compared center of gravity (COG) velocity during quiet standing on a foam surface during three test positions: i) resting jaw, ii) open jaw, and iii) clenching; these were tested in two conditions: with eyes open and with eyes closed. The COG velocity decreased significantly during clenching in comparison to both open and resting jaw positions (p<0.0001). This suggests that the jaw sensory-motor system can modulate postural mechanisms. We conclude that jaw clenching can enhance postural stability during standing on an unstable surface in both the presence and absence of visual input in healthy adults and suggest that this should be taken into consideration in treatment and rehabilitation planning for patients with postural instability. PMID:26329542

  10. [Prevention of spine deformities in adolescents due to inadequate posture].

    PubMed

    Ramova, Elizabeta Popova; Lazović, Milica

    2010-01-01

    The spine deformities tend to increase, and in 90% of children they change the quality of life. The aim of this study was to determine the percents of spinal deformity in our population of adolescents, and long bad posture in and out of school as a factor for its increase. The study included 124 adolescents attending High Musical School in Bitola and Skopje, who underwent four standard spine tests and an interview. According to the test 3, 50% of the examined adolescents in Bitola and 69% in Skopje had the postural spine deformity, the average being 59.5%. The results obtained by the questionnaire showed that 50% of adolescents did not have any physical activity out of school, the longest daily activity, lasting four hours, in 48% of the examinees was practising their musical instruments; 40% of the examinees spent two hours watching TV or using the computer, whereas 18% did not use any of them at all. The bad spine posture tends to deteriorate in adolescents and the factor influencing this result should be established by studies aimed at determining the effects of physical activity on reducing such deformities, since the specific type of their education induces the risk of developing pain and early degenerative changes of the spine, which are predominant in the professionals.

  11. Low-frequency force steadiness practice in plantar flexor muscle reduces postural sway during quiet standing.

    PubMed

    Oshita, Kazushige; Yano, Sumio

    2011-01-01

    The purpose of this study was to assess the effect of low-frequency force steadiness practice in the plantar flexor muscles on postural sway during quiet standing. Healthy young 21 men (21±1 yrs) were randomly assigned to a practice group (n=14) and a nonexercising control group (n=7). Practice groups were divided by frequency of practice: 7 participants practiced once a week, and the other 7 twice a week, for 4 weeks. Steadiness practice required practice group to 5 sets of 60-s contraction at levels corresponding to 10% and 20% maximal voluntary contraction (MVC) in the plantar flexor muscles. The 4-week-long practice period reduced the force fluctuations (assessed as the standard deviation (SD) of the outputted force during steady isometric plantar flexion) and postural sway (assessed as SD of the center of mass velocity during quiet standing). However, these practice effects were not significantly affected by the practice frequencies (1 vs. 2 sessions per week) examined in this study. Further, a linear regression analysis revealed the association between prepractice postural sway and the relative change in postural sway by the practice (r=-0.904) in the practice group. These results suggest that the steadiness practice in plantar flexor muscles improves postural stability during quiet standing, even though the practice is low-frequency (once a week) and low-intensity (within 20% MVC). These practice effects are dependent on prepractice postural stability. Further, the present results have provided the functional significance of force fluctuation in lower limb muscles.

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

    PubMed

    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.

  13. Dementia alters standing postural adaptation during a visual search task in older adult men

    PubMed Central

    Joŕdan, Azizah J.; McCarten, J. Riley; Rottunda, Susan; Stoffregen, Thomas A.; Manor, Brad; Wade, Michael G.

    2015-01-01

    This study investigated the effects of dementia on standing postural adaptation during performance of a visual search task. We recruited 16 older adults with dementia and 15 without dementia. Postural sway was assessed by recording medial-lateral (ML) and anterior-posterior (AP) center-of-pressure when standing with and without a visual search task; i.e., counting target letter frequency within a block of displayed randomized letters. ML sway variability was significantly higher in those with dementia during visual search as compared to those without dementia and compared to both groups during the control condition. AP sway variability was significantly greater in those with dementia as compared to those without dementia, irrespective of task condition. In the ML direction, the absolute and percent change in sway variability between the control condition and visual search (i.e., postural adaptation) was greater in those with dementia as compared to those without. In contrast, postural adaptation to visual search was similar between groups in the AP direction. As compared to those without dementia, those with dementia identified fewer letters on the visual task. In the non-dementia group only, greater increases in postural adaptation in both the ML and AP direction, correlated with lower performance on the visual task. The observed relationship between postural adaptation during the visual search task and visual search task performance—in the non-dementia group only—suggests a critical link between perception and action. Dementia reduces the capacity to perform a visual-based task while standing and thus appears to disrupt this perception-action synergy. PMID:25770830

  14. Discrepancy Between Standing Posture and Sagittal Balance During Walking in Adult Spinal Deformity Patients.

    PubMed

    Arima, Hideyuki; Yamato, Yu; Hasegawa, Tomohiko; Togawa, Daisuke; Kobayashi, Sho; Yasuda, Tatsuya; Banno, Tomohiro; Oe, Shin; Matsuyama, Yukihiro

    2017-01-01

    Retrospective case series. The present study aimed to determine the characteristics of patients with adult spinal deformity (ASD) with a discrepancy between standing and walking postures. Standing radiographic parameters are typically used to evaluate patients with ASD. Patients with ASD with relatively good sagittal alignment on standing radiography have, however, been reported to walk with a forward trunk tilt. Patients with ASD (n = 93; 13 men, 80 women; mean age, 65.0 yr) who underwent corrective surgery and preoperative gait analysis at our hospital between 2011 and 2013 were included. Spine radiographs and gait analysis data were acquired preoperatively. Standing-trunk tilt angle (STA) on lateral standing x-ray, gait-trunk tilt angle (GTA) from lateral gait images, and radiographic parameters of the spine and pelvis (lumbar lordosis [LL], pelvic tilt, and sagittal vertical axis) were measured. We calculated the increasing trunk tilt angle (ITA), by subtracting the STA from the GTA, for use as an index of discrepancy between standing posture and sagittal balance during walking. We examined the relation between radiographic parameters and ITA. The mean preoperative STA and GTA were 3.5° and 11.1°, respectively. The mean preoperative ITA, which represents the degree of discrepancy between standing posture and sagittal balance during walking, was 7.6°. The mean preoperative sagittal vertical axis, LL, pelvic incidence (PI), pelvic tilt, and PI minus LL were 102.6 mm, 20.3°, 52.9°, 32.1°, and 32.6°, respectively. The PI minus LL mismatch was positively correlated with the ITA (R = 0.237, P = 0.023). In particular, patients with ASD with a PI minus LL mismatch of more than 40° had a significantly greater ITA. Gait analysis revealed that a preoperative standing-walking discrepancy is associated with severe PI - LL mismatch. 4.

  15. Reliability of forward head posture evaluation while sitting, standing, walking and running.

    PubMed

    Lee, Chang-Hyung; Lee, Sojeong; Shin, Gwanseob

    2017-10-01

    Forward head posture has been evaluated mostly by visual observation or simple non-invasive measurements without a standardized evaluation method or protocol. In this experimental study, the reliability of existing forward head-posture measurement methods was evaluated by computing the intra-class correlation coefficients of three different head-position variables (two horizontal gap variables and one head-orientation variable) in seven different posture conditions from 20 asymptomatic participants. The position variables of the head were measured three times using a three-dimensional motion capture system while sitting comfortably, sitting with the back straight, standing comfortably, standing with the back straight, walking at 4 and 6km/h on a treadmill, and running at 8km/h on a treadmill. Intra-class correlation coefficients between repetitive measures ranged from 0.81 to 0.96, and high correlation coefficient values (>0.9) were produced when the head-position variables were measured during straight sitting, straight standing, and walking at 6km/h. Among the three head-position variables, a horizontal gap between the tragus and the 7th cervical vertebra was recorded more consistently than other variables. Results of this study highlight the importance of a standardized evaluation protocol for more reliable assessment of the forward head posture. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Postural Rehabilitation for Adolescent Idiopathic Scoliosis during Growth

    PubMed Central

    Weiss, Hans-Rudolf; Moramarco, Marc Michael; Borysov, Maksym; Lee, Sang Gil; Nan, Xiaofeng; Moramarco, Kathryn Ann

    2016-01-01

    Long-term follow-up of untreated patients with adolescent idiopathic scoliosis (AIS) indicates that, with the exception of some extremely severe cases, AIS does not have a significant impact on quality of life and does not result in dire consequences. In view of the relatively benign nature of AIS and the long-term complications of surgery, the indications for treatment should be reviewed. Furthermore, recent studies have shown that scoliosis-specific exercises focusing on postural rehabilitation can positively influence the spinal curvatures in growing adolescents. Experiential postural re-education is a conservative, non-invasive approach, and its role in the management of AIS warrants further study. This article reviews current evidence for the inclusion of various forms of postural reeducation in the management of AIS. Recent comprehensive reviews have been researched including a manual and PubMed search for evidence regarding the effectiveness of physical/postural re-education/physiotherapy programs in growing AIS patients. This search revealed that there were few studies on the application of postural re-education in the management of AIS. These studies revealed that postural re-education in the form of exercise rehabilitation programs may have a positive influence on scoliosis; however, the various programs were difficult to compare. More research is necessary. There is at present Level 1 evidence for the effectiveness of Schroth scoliosis exercises in the management of AIS. Whether this evidence can be extrapolated to include other forms of scoliosis- pattern-specific exercises requires further investigation. Because corrective postures theoretically reduce the asymmetric loading of the spinal deformities and reverse the vicious cycle of spinal curvature progression, their integration into AIS programs may be beneficial and should be further examined. PMID:27340540

  17. Influence of Transcranial Direct Current Stimulation to the Cerebellum on Standing Posture Control

    PubMed Central

    Inukai, Yasuto; Saito, Kei; Sasaki, Ryoki; Kotan, Shinichi; Nakagawa, Masaki; Onishi, Hideaki

    2016-01-01

    Damage to the vestibular cerebellum results in dysfunctional standing posture control. Patients with cerebellum dysfunction have a larger sway in the center of gravity while standing compared with healthy subjects. Transcranial direct current stimulation (tDCS) is a noninvasive technique for selectively exciting or inhibiting specific neural structures with potential applications in functional assessment and treatment of neural disorders. However, the specific stimulation parameters for influencing postural control have not been assessed. In this study, we investigated the influence of tDCS when applied over the cerebellum on standing posture control. Sixteen healthy subjects received tDCS (20 min, 2 mA) over the scalp 2 cm below the inion. In Experiment 1, all 16 subjects received tDCS under three stimulus conditions, Sham, Cathodal, and Anodal, in a random order with the second electrode placed on the forehead. In Experiment 2, five subjects received cathodal stimulation only with the second electrode placed over the right buccinator muscle. Center of gravity sway was measured twice for 60 s before and after tDCS in a standing posture with eyes open and legs closed, and average total locus length, locus length per second, rectangular area, and enveloped area were calculated. In Experiment 1, total locus length and locus length per second decreased significantly after cathodal stimulation but not after anodal or sham stimulation, while no tDCS condition influenced rectangular or enveloped areas. In Experiment 2, cathodal tDCS again significantly reduced total locus length and locus length per second but not rectangular and enveloped areas. The effects of tDCS on postural control are polarity-dependent, likely reflecting the selective excitation or inhibition of cerebellar Purkinje cells. Cathodal tDCS to the cerebellum of healthy subjects can alter body sway (velocity). PMID:27458358

  18. A photographic method for multi-plane assessment of adolescent posture.

    PubMed

    Puglisi, Filadelfio; Donati, Paolo; Marini, Mirca; Romeo, Loris; Scidone, Stefano; Ferrari, Robert

    2014-01-01

    To date there have been no photographic methods reported for assessing the standing postural alignment in a manner that can be used in large scale populations. The purpose of this study was to describe a photographic, multi-plane postural measurement method in a pilot group of subjects in a school setting. A total of 83 healthy male adolescents, volunteered for the study, were photographed. The mean age was 14.5 +/- 0.7 years (range 14-16). The mean height was 170.7 +/- 3.5 cm, (range 155-187), and the mean weight was 63.2 +/- 13.9 kg (range 37-110). During procedure, subjects stood on a platform, with specific markers placed on landmarks that could be identified photographically. Photography was accomplished from above, below, each side, and front and back. These six photographs permit views to be projected onto the six sides of an ideal parallelepiped enclosing the body. Five angles were calculated and reported to describe the alignments of the head, shoulders, torso, and pelvis. As expected the means of each of the five angles were small, the absolute value varying from 0 to 7 degrees. This paper describes the results of a simple, practical, and effective way to gather data concerning standing postural alignment in adolescents using a photographic technique. This technique will be used to form a normative database by large-scale studies. Using this approach, a number of angles can be calculated and eventually models can be developed, relating these angles to sitting posture measurements and to symptoms.

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

    PubMed Central

    2012-01-01

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

  20. Support surface related changes in feedforward and feedback control of standing posture

    PubMed Central

    Mohapatra, Sambit; Kukkar, Komal K.; Aruin, Alexander S.

    2013-01-01

    The aim of the study was to investigate the effect of different support surfaces on feedforward and feedback components of postural control. Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing on a rigid platform, foam, and wobble board with eyes open or closed. Electrical activity of nine trunk and leg muscles and displacements of the center of pressure were recorded and analyzed during the time frames typical of feedforward and feedback postural adjustments. Feedforward control of posture was characterized by earlier activation of anterior muscles when the subjects stood on foam compared to a wobble board or a firm surface. In addition, the magnitude of feedforward muscle activity was the largest when the foam was used. During the feedback control, anterior muscles were activated prior to posterior muscles irrespective of the nature of surface. Moreover, the largest muscle activity was seen when the supporting surface was foam. Maximum CoP displacement occurred when subjects were standing on a rigid surface. Altering support surface affects both feedforward and feedback components of postural control. This information should be taken into consideration in planning rehabilitation interventions geared towards improvement of balance. PMID:24268589

  1. Variation in percentage weight bearing with changes in standing posture during water immersion: implication for clinical practice

    PubMed Central

    2014-01-01

    Background The degree of weightlessness during water immersion is usually estimated through percentage weight bearing (PWB). However, variations in PWB in different standing postures have not been documented. The study was designed to investigate the PWB of apparently healthy individuals in four standing postures at the anterior superior iliac spine level of immersion. Methods One hundred and ninety-three consenting undergraduates were purposively enlisted in this study. Participants’ body weight (BW) was measured on land as well as in Erect Standing (ES), Grasp-Inclined-Prone-Standing (GIPS), Half-Grasp-Inclined-Towards-Side Standing (HGITSS) and Inclined-Standing with Head Support (ISHS) postures in hydro pool, using a specially designed water-proof weighing scale. PWB was calculated by dividing BW in water by BW on land and multiplying by 100. Data were analyzed using mean, standard deviation and ANOVA at α = 0.05. Results The mean age and BW (on land) of the participants were 22.4 years and 60.7 kg respectively. Participants’ PWB were significantly different (p < 0.05) across the four standing postures. PWB was highest in ES and lowest in ISHS; PWB in ES (52.3 ± 5.8) being significantly higher (p < 0.001) than that observed in the derived standing postures. Further, PWB in GIPS (43.3 ± 5.6) and ISHS (43.2 ± 7.3) were significantly lower than in HGITSS (47.4 ± 5.2) posture while PWB in GIPS and ISHS postures were not significantly different (p > 0.05). Conclusion Changes in standing posture have significant effect on PWB in hydro pool. The finding has implication for partial weight bearing exercises in hydro pool. PMID:25091034

  2. Quantification of the postural and technical errors in asymptomatic adults using direct 3D whole body scan measurements of standing posture.

    PubMed

    Tomkinson, Grant R; Shaw, Linda G

    2013-02-01

    Measurement repeatability has important decision-making implications for clinicians and researchers when assessing individuals. The aims of this study were to quantify: (a) the repeatability of direct measurements of standing posture using three dimensional (3D) whole body scanning, and (b) the magnitude of the postural and technical errors involved. Fifty-two asymptomatic adults were scanned twice, 24h apart, using the Vitus Smart 3D whole body scanner. Eleven clinically relevant standing postural measurements were calculated from scan-extracted data. The process was repeated with 10 shop mannequins. Systematic error was expressed as absolute changes in means and as standardised effect sizes, with random (within-subject) error expressed as the typical error. Technical error was calculated as the typical error in the measurement of mannequins; total error as the typical error in the measurement of subjects; and postural error as the square root of the difference between the squared total error and the squared technical error. Most standing postural measurements demonstrated good repeatability, with median (95% CI) systematic and random errors of -0.1° (1.1°) and 2.8° (1.9°), respectively. However, head and neck postures demonstrated poor repeatability due to large random errors brought about by large postural errors. Overall, most of the error was due to postural error rather than technical error. The relatively small technical errors highlight that this 3D measurement process is generally repeatable, while the relatively large postural errors related to the head and neck suggest that these postures probably lack the precision to be clinically useful using this procedure. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Cervical and shoulder postural assessment of adolescents between 15 and 17 years old and association with upper quadrant pain

    PubMed Central

    Ruivo, Rodrigo M.; Pezarat-Correia, Pedro; Carita, Ana I.

    2014-01-01

    Background: There is sparse literature that provides evidence of cervical and shoulder postural alignment of 15 to 17-year-old adolescents and that analyzes sex differences. Objectives: To characterize the postural alignment of the head and shoulder in the sagittal plane of 15 to 17-year-old Portuguese adolescents in natural erect standing and explore the relationships between three postural angles and presence of neck and shoulder pain. Method: This cross-sectional study was conducted in two secondary schools in Portugal. 275 adolescent students (153 females and 122 males) aged 15 to 17 were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and PAS software. The American Shoulder and Elbow Surgeons Shoulder Assessment (ASES) was used to assess shoulder pain, whereas neck pain was self-reported with a single question. Results: Mean values of sagittal head, cervical, and shoulder angles were 17.2±5.7, 47.4±5.2, and 51.4±8.5º, respectively. 68% of the participants revealed protraction of the head, whereas 58% of them had protraction of the shoulder. The boys showed a significantly higher mean cervical angle, and adolescents with neck pain revealed lower mean cervical angle than adolescents without neck pain. 53% of the girls self-reported regular neck pain, contrasting with 19% of the boys. Conclusions: This data shows that forward head and protracted shoulder are common postural disorders in adolescents, especially in girls. Neck pain is prevalent in adolescents, especially girls, and it is associated with forward head posture. PMID:25054381

  4. The Complexity of Standing Postural Sway Associates with Future Falls in Community-Dwelling Older Adults: The MOBILIZE Boston Study.

    PubMed

    Zhou, Junhong; Habtemariam, Daniel; Iloputaife, Ikechukwu; Lipsitz, Lewis A; Manor, Brad

    2017-06-07

    Standing postural control is complex, meaning that it is dependent upon numerous inputs interacting across multiple temporal-spatial scales. Diminished physiologic complexity of postural sway has been linked to reduced ability to adapt to stressors. We hypothesized that older adults with lower postural sway complexity would experience more falls in the future. 738 adults aged ≥70 years completed the Short Physical Performance Battery test (SPPB) test and assessments of single and dual-task standing postural control. Postural sway complexity was quantified using multiscale entropy. Falls were subsequently tracked for 48 months. Negative binomial regression demonstrated that older adults with lower postural sway complexity in both single and dual-task conditions had higher future fall rate (incident rate ratio (IRR) = 0.98, p = 0.02, 95% Confidence Limits (CL) = 0.96-0.99). Notably, participants in the lowest quintile of complexity during dual-task standing suffered 48% more falls during the four-year follow-up as compared to those in the highest quintile (IRR = 1.48, p = 0.01, 95% CL = 1.09-1.99). Conversely, traditional postural sway metrics or SPPB performance did not associate with future falls. As compared to traditional metrics, the degree of multi-scale complexity contained within standing postural sway-particularly during dual task conditions- appears to be a better predictor of future falls in older adults.

  5. Shape and thickness of cushion in a standing aid to support a forward bending posture: effects on posture, muscle activities and subjective discomfort.

    PubMed

    Iwakiri, Kazuyuki; Sotoyama, Midori; Mori, Ippei; Jonai, Hiroshi; Saito, Susumu

    2004-01-01

    In order to prevent low back pain (LBP) during dishwashing, we developed three types of aid with a thick cushion for supporting the shins and evaluated the effects of the standing aid on the subjective discomfort and muscle activities. Nine female volunteers were asked to wash plates in each of four working postures: (a) without the standing aid, (b) with the round type of aid, (c) with the small rectangular type of aid, and (d) with the large rectangular type of aid. With the three types of aid, the subjects were instructed to support the shins with the standing aid and to support the abdomen with the edge of a kitchen counter. In the three postures with the standing aid, 21.5 +/- 10.0% of the weight was supported with the standing aid and the kitchen counter. The subjective discomfort was milder and the muscle activity level in the low back was lower in the three postures with the standing aid than in the posture without the aid. It was thought that the round type of aid would be more effective in decreasing the discomfort in many of body regions and the muscle load on the low back than either of the rectangular types of aid. Therefore, it was suggested that the standing aid had the desired effect in decreasing discomfort and muscle load on the low back during dishwashing.

  6. [Studies on the largest Lyapunov exponents of the standing posture in patients with unilateral vestibular dysfunction].

    PubMed

    Mizuta, Keisuke; Tokita, Takashi; Ito, Yatsuji; Aoki, Mitsuhiro; Kuze, Bunya

    2009-12-01

    In the present study, we investigated the body sway in patients with unilateral vestibular dysfunction by the largest Lyapunov exponents using a chaotic time series analysis. The largest Lyapunov exponent is regarded as a parameter indexing an orbital instability. Subjects consisted of 55 normal healthy subjects, 11 patients diagnosed as having vestibular neuritis (VN), 6 patients diagnosed as having sudden deafness (SD) with vertigo, 23 patients diagnosed as having Meniere disease (MD), 11 patients diagnosed as having benign paroxysmal positional vertigo (BPPV) and 14 patients diagnosed as having other vestibular disorders. Using a stabilometer, the sway of the body center of gravity in an upright standing position was recorded with eyes open and closed for 60 seconds under each condition. From the time series data obtained, the largest Lyapunov exponents were calculated using a chaos analysis program. In normal healthy subjects and patients with unilateral vestibular dysfunction, the largest Lyapunov exponents on right-left sway were larger than those on forward-backward sway with eyes open and closed. The largest Lyapunov exponents in patients with unilateral vestibular dysfunction on forward-backward sway with eyes closed were significantly larger than those in normal healthy subjects. A few patients with the instability of standing posture judged from conventional analysis (area of sway, locus length per time) showed higher values of the LLE. We investigated the variation of the values of the largest Lyapunov exponents in patients with unilateral vestibular dysfunction at each stage during recovery from their vestibular damage. The largest Lyapunov exponents at the early stage with stable standing posture were significantly higher than those at the late stable stage with stable standing posture. Some patients at the very early stage had lower values of the largest Lyapunov exponents. We speculate that the orbital instability indicated by the values of the

  7. Control of standing balance at leaning postures with functional neuromuscular stimulation following spinal cord injury.

    PubMed

    Audu, Musa L; Odle, Brooke M; Triolo, Ronald J

    2017-07-24

    This study systematically explored the potential of applying feedback control of functional neuromuscular stimulation (FNS) for stabilizing various erect and leaning standing postures after spinal cord injury (SCI). Perturbations ranging from 2 to 6% body weight were applied to two subjects with motor complete thoracic level SCI who were proficient at standing with implanted multichannel neural stimulators to activate the ankle, knee, hip and trunk muscles. The subjects stood with four different postures: erect, forward, forward-right and forward-left. Repeatable and controlled perturbations were applied in the forward, backward, rightward and leftward directions by linear actuators pulling on ropes attached to the subjects via a belt worn just above the waist. Upper extremity (UE) forces exerted on a stationary walker were measured with load cells attached to the handles. A feedback controller based on center of pressure (CoP) varied the stimulation levels to the otherwise paralyzed muscles so as to resist the effects of the perturbations. The effect of the feedback controller was compared to the case where only open-loop baseline stimulation was applied. This was done in terms of: (a) maximum resultant UE force exerted by the subjects on the walker, (b) maximum resultant CoP overshoot and (c) CoP root-mean-square deviation (RMSD). Feedback control resulted in significant reductions in the mean values of the majority of outcome values compared to baseline open-loop stimulation. Maximum resultant UE force was reduced by as much as 50% in one of the postures for one of the subjects. RMSD and maximum CoPs were reduced by as much as 75 and 70%, respectively, with feedback control. These results indicate that feedback control can be used to reject destabilizing disturbances in individuals with SCI using FNS not only for erect postures but also for leaning postures typically adopted during reaching while attempting various activities of daily living.

  8. Static Standing Balance in Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Villarroya, M. Adoracion; Gonzalez-Aguero, Alejandro; Moros-Garcia, Teresa; de la Flor Marin, Mario; Moreno, Luis A.; Casajus, Jose A.

    2012-01-01

    Aim: To analyse static-standing-balance of adolescents with Down syndrome (DS). Methods: Thirty-two adolescents with DS aged 10-19 years (DSG); 33 adolescents, age/sex-matched, without DS (CG). Static-standing-balance under four conditions (C1: open-eyes/fixed-foot-support; C2: closed-eyes/fixed-foot-support; C3: open-eyes/compliant-foot-support;…

  9. Static Standing Balance in Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Villarroya, M. Adoracion; Gonzalez-Aguero, Alejandro; Moros-Garcia, Teresa; de la Flor Marin, Mario; Moreno, Luis A.; Casajus, Jose A.

    2012-01-01

    Aim: To analyse static-standing-balance of adolescents with Down syndrome (DS). Methods: Thirty-two adolescents with DS aged 10-19 years (DSG); 33 adolescents, age/sex-matched, without DS (CG). Static-standing-balance under four conditions (C1: open-eyes/fixed-foot-support; C2: closed-eyes/fixed-foot-support; C3: open-eyes/compliant-foot-support;…

  10. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis.

    PubMed

    Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

    2017-01-01

    Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12-18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

  11. Comparison of the effective dose rate to aircrew members using hybrid computational phantoms in standing and sitting postures.

    PubMed

    Alves, M C; Galeano, D C; Santos, W S; Lee, Choonsik; Bolch, Wesley E; Hunt, John G; da Silva, A X; Carvalho, A B

    2016-12-01

    Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members. We found that although the better description of the posture in which the aircrews are exposed, the results of the effective dose rate calculated with the phantom in the sitting posture were very similar to the results of the phantom in the standing posture. In fact we observed only a 1% difference. These findings indicate the adequacy of the use of dose conversion coefficients for the phantom in the standing posture in aircrew dosimetry. We also validated our results comparing the effective dose rate obtained using the standing phantom with values reported in the literature. It was observed that the results presented in this study are in good agreement with other authors (the differences are below 30%) who have measured and calculated effective dose rates using different phantoms.

  12. Age-gender differences in the postural sway during squat and stand-up movement.

    PubMed

    Kim, Ji-Won; Kwon, Yuri; Ho, Yeji; Jeon, Hyeong-Min; Bang, Min-Jung; Jun, Jae-Hoon; Eom, Gwang-Moon; Park, Byung Kyu; Cho, Yeong Bin

    2014-01-01

    Incidence of falling among elderly female has been reported to be much higher than that of elderly male. Although the gender differences in the elderly were reported for the static postural sway, there has been no investigation of the gender difference for the dynamic postural sway. This study investigates how age and gender affect the postural sway during dynamic squat and stand-up movement. 124 subjects (62 subjects for each of young and elderly) performed consecutive squat and stand-up movement, 2 times in one session, and 2 sessions per subject. Center of pressure (COP) was measured using force platform during the test. Outcome measures included peak-to-peak sways of the COP (COP sway) in the sagittal plane (anteroposterior) and frontal plane (mediolateral) and also those normalized by body height. Two-way ANOVA and post-hoc comparisons were performed for the outcome measures with the independent factors of age and gender. All outcome measures, excluding mediolateral COP sway, showed significant interaction of age and gender (p<0.05). Post-hoc test revealed that only female showed increase in COP sway with age. When normalized by height, increase in COP sways (both directions) with age significant only in women resulted in greater sways in elderly female than elderly male. This may be related to the greater fall rate of elderly female than that of elderly men while performing dynamic activities.

  13. Enhanced stretch reflex excitability in the soleus muscle during passive standing posture in humans.

    PubMed

    Shimba, Sachio; Kawashima, Noritaka; Ohta, Yuji; Yamamoto, Shin-ichiroh; Nakazawa, Kimitaka

    2010-06-01

    The purpose of this study was to test whether the spinal reflex excitability of the soleus muscle is modulated as posture changes from a supine to a passive upright position. Eight healthy subjects (29.6+/-5.4 yrs) participated in this study. Stretch and H-reflex responses were elicited while the subjects maintained passive standing (ST) and supine (SP) postures. The passive standing posture was accomplished by using a gait orthosis to which a custom-made device was mounted to elicit stretch reflex in the soleus muscle. This orthosis makes it possible to elicit stretch and H-reflexes without background muscle activity in the soleus muscle. The results revealed that the H-reflex amplitude in the ST was smaller than that in the SP condition, which is in good agreement with previous reports. On the other hand, the stretch reflex was significantly larger in the ST than in the SP condition. Since the experimental conditions of both the stretch and H-reflex measurements were exactly the same, the results were attributed to differences in the underlying neural mechanisms of the two reflex systems: different sensitivity of the presynaptic inhibition onto the spinal motoneuron pool and/or a change in the muscle spindle sensitivity. (c) 2009 Elsevier Ltd. All rights reserved.

  14. Effect of sitting pause times on postural stability after supine-to-standing transfer in dimly lit environments.

    PubMed

    Johnson, Eric G; Meltzer, Jonathan D

    2012-01-01

    Falls are common and often take place in the home. Risk of fall increases if the environment is dimly lit. Longer sitting pause times, before standing, might improve postural stability after standing from a supine position. The purpose of this investigation was to measure the effects of sitting pause times on postural sway velocity immediately following a supine-to-standing transfer in a dimly lit room in older and younger adult women. Five women aged 65 to 70 years and 5 aged 23 to 30 years participated in the study. On each of 2 consecutive days, study participants lay on a mat table with their eyes closed for 45 minutes before performing a supine-to-standing transfer in a dimly lit room. Sitting pause times of 2 seconds and 30 seconds preceded the transfers. Mean postural sway velocity for the whole sample and for younger and older groups was less after a 30-second pause time than that after a 2-second pause time (sample, P = .001; young, P = .019; old, P = .021). No significant difference in mean postural sway velocity was observed between the 2 groups (P > .05). Total mean postural sway velocity was less when study participants performed a sitting pause of 30 seconds before standing in a dimly lit room. These results suggest that longer sitting pause times may provide improved adaptability to dimly lit environments contributing to improved postural stability.

  15. Postural habits and weight of backpacks of Portuguese adolescents: Are they associated with scoliosis and low back pain?

    PubMed

    Minghelli, Beatriz; Oliveira, Raul; Nunes, Carla

    2016-04-07

    The adoption of incorrect postures or carrying overweight backpacks may contribute to the development of musculoskeletal disorders in school children. This study evaluated the weight of backpacks and the postural habits adopted in schools by Portuguese adolescents, and their association with scoliosis and low back pain (LBP). The sample comprised 966 Portuguese students, aged between 10 and 16 years. The instruments included a questionnaire to characterize the presence of LBP and the postural habits adopted by students, the weighing of backpacks and a scoliometer to evaluate scoliosis. No association was observed between assuming incorrect postures and carrying overweight backpacks, in students with scoliosis. Students who adopted incorrect sitting postures had 1.77 times the risk (95% CI: 1.32-2.36; p < 0.001) of developing LBP; those positioned incorrectly whilst watching TV and playing games had 1.44 times the risk (95% CI: 1.08-1.90; p = 0.012) of developing LBP; and those standing incorrectly had 2.39 the risk (95% CI: 1.52-3.78; p < 0.001) of developing LBP. The results revealed that students who sat with the spine positioned wrongly, as well as those who were standing incorrectly, were more likely to present with LBP.

  16. Study of the human postural control system during quiet standing using detrended fluctuation analysis

    NASA Astrophysics Data System (ADS)

    Teresa Blázquez, M.; Anguiano, Marta; de Saavedra, Fernando Arias; Lallena, Antonio M.; Carpena, Pedro

    2009-05-01

    The detrended fluctuation analysis is used to study the behavior of different time series obtained from the trajectory of the center of pressure, the output of the activity of the human postural control system. The results suggest that these trajectories present two different regimes in their scaling properties: persistent (for high frequencies, short-range time scale) to antipersistent (for low frequencies, long-range time scale) behaviors. The similitude between the results obtained for the measurements, done with both eyes open and eyes closed, indicate either that the visual system may be disregarded by the postural control system while maintaining the quiet standing, or that the control mechanisms associated with each type of information (visual, vestibular and somatosensory) cannot be disentangled with the type of analysis performed here.

  17. Modelling resonances of the standing body exposed to vertical whole-body vibration: Effects of posture

    NASA Astrophysics Data System (ADS)

    Subashi, G. H. M. J.; Matsumoto, Y.; Griffin, M. J.

    2008-10-01

    Lumped parameter mathematical models representing anatomical parts of the human body have been developed to represent body motions associated with resonances of the vertical apparent mass and the fore-and-aft cross-axis apparent mass of the human body standing in five different postures: 'upright', 'lordotic', 'anterior lean', 'knees bent', and 'knees more bent'. The inertial and geometric parameters of the models were determined from published anthropometric data. Stiffness and damping parameters were obtained by comparing model responses with experimental data obtained previously. The principal resonance of the vertical apparent mass, and the first peak in the fore-and-aft cross-axis apparent mass, of the standing body in an upright posture (at 5-6 Hz) corresponded to vertical motion of the viscera in phase with the vertical motion of the entire body due to deformation of the tissues at the soles of the feet, with pitch motion of the pelvis out of phase with pitch motion of the upper body above the pelvis. Upward motion of the body was in phase with the forward pitch motion of the pelvis. Changing the posture of the upper body had minor effects on the mode associated with the principal resonances of the apparent mass and cross-axis apparent mass, but the mode changed significantly with bending of the legs. In legs-bent postures, the principal resonance (at about 3 Hz) was attributed to bending of the legs coupled with pitch motion of the pelvis in phase with pitch motion of the upper body. In this mode, extension of the legs was in phase with the forward pitch motion of the upper body and the upward vertical motion of the viscera.

  18. Effects of transporting an infant on the posture of women during walking and standing still.

    PubMed

    Junqueira, Lúcia Desideri; Amaral, Lia Queiroz; Iutaka, Alexandre Sadao; Duarte, Marcos

    2015-03-01

    We investigated the effects on women of carrying an infant in front, focusing on the pelvic and spinal posture and the displacement of the body's center of gravity. For such, we compared mothers to non-mothers not carrying anything or carrying the same load (a doll) and the mothers carrying their infants. Twenty mothers and 44 women who did not have children were analyzed for their movement and posture during walking and standing still with a motion capture system. Walking while carrying a load was slower and with a shorter stride length than while not carrying a load. The mothers' group walked slower and with a shorter stride length than the non-mothers' group. During walking and standing still, the women decreased their angle of pelvic anteversion, increased lumbar lordosis, increased thoracic kyphosis, and increased trunk backward inclination while carrying a load in comparison with not carrying anything. In addition, we observed some small differences in the spinal angles of mothers when carrying their infants compared to when carrying a doll. When standing still, the women carrying a load displaced backwards their vertical projection of the center of gravity to exactly compensate the destabilizing load at the front that resulted in no net change of the body-plus-load center of gravity. In general, these changes are qualitatively similar to the ones observed during pregnancy.

  19. The effect of standing and sitting postures on breathing in brass players.

    PubMed

    Price, Kevin; Schartz, Philippe; Watson, Alan Hd

    2014-01-01

    The object of this study was to examine the effect of posture on breathing in brass players. Breathing when standing was compared with sitting erect on a flat, downward or upward sloping seat, or on a reclining seat. Spirometry was used to measure aspects of lung function. Muscle activity and respiratory movements during different playing tasks were recorded using electromyography and inductive plethysmography. Only sitting in a reclining position produced statistically significantly lower values for VC, FVC, FEV1, PEF than standing. When players were asked to produce a note of maximum duration, only a downward sloping seat caused a significant change (an 11% reduction) compared to standing. When seated, the abdominal component of respiratory movement was significantly higher during these long notes than when standing, though maximum activity in abdominal wall muscles was significantly reduced (by 32-44%). On a downward sloping seat, muscle activity was significantly higher (9%) than on a flat seat. Tongued and untongued sforzando notes recruited significantly less abdominal muscle activity (33-67%) when sitting than when standing. When playing a trumpet study, abdominal muscle activity was significantly reduced on a downward sloping seat (by 32%) and on a flat seat (by 40%) in comparison to standing. Muscle activity in the two sitting positions were not significantly different. Though brass players are often told to "sit as if standing", abdominal muscle activity is always significantly reduced when sitting on a flat or downward sloping seat, however when greater respiratory effort is required, activity on downward sloping seats may rise closer to that of standing.

  20. Impaired postural control reduces sit-to-stand-to-sit performance in individuals with chronic obstructive pulmonary disease.

    PubMed

    Janssens, Lotte; Brumagne, Simon; McConnell, Alison K; Claeys, Kurt; Pijnenburg, Madelon; Goossens, Nina; Burtin, Chris; Janssens, Wim; Decramer, Marc; Troosters, Thierry

    2014-01-01

    Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to the decreased STSTS performance in individuals with COPD. Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each sit, sit-to-stand, stand and stand-to-sit phase was recorded. Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (19±6 vs. 13±4 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups. Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD.

  1. Long-Term Effects from Bacterial Meningitis in Childhood and Adolescence on Postural Control

    PubMed Central

    Petersen, Hannes; Patel, Mitesh; Ingason, Einar F.; Einarsson, Einar J.; Haraldsson, Ásgeir; Fransson, Per-Anders

    2014-01-01

    Bacterial meningitis in childhood is associated with cognitive deficiencies, sensorimotor impairments and motor dysfunction later in life. However, the long-term effects on postural control is largely unknown, e.g., whether meningitis subjects as adults fully can utilize visual information and adaptation to enhance stability. Thirty-six subjects (20 women, mean age 19.3 years) treated in childhood or adolescence for bacterial meningitis, and 25 controls (13 women, mean age 25.1 years) performed posturography with eyes open and closed under unperturbed and perturbed standing. The meningitis subjects were screened for subjective vertigo symptoms using a questionnaire, clinically tested with headshake and head thrust test, as well as their hearing was evaluated. Meningitis subjects were significantly more unstable than controls during unperturbed (p≤0.014) and perturbed standing, though while perturbed only with eyes open in anteroposterior direction (p = 0.034) whereas in lateral direction both with eyes open and closed (p<0.001). Meningitis subjects had poorer adaption ability to balance perturbations especially with eyes open, and they frequently reported symptoms of unsteadiness (88% of the subjects) and dizziness (81%), which was found significantly correlated to objectively decreased stability. Out of the 36 subjects only 3 had unilateral hearing impairment. Hence, survivors of childhood bacterial meningitis may suffer long-term disorders affecting postural control, and would greatly benefit if these common late effects became generally known so treatments can be developed and applied. PMID:25405756

  2. Preliminary results of dancing exercise on postural stability in adolescent females.

    PubMed

    Cheng, Hsu-Sheng; Law, Cheung-Lun; Pan, Hui-Fang; Hsiao, Yueh-Ping; Hu, Jeng-Ho; Chuang, Fu-Kai; Huang, Mao-Hsiung

    2011-12-01

    Twenty-six female student dancers of Chung-hua school of Art (mean age 17.5 ± 0.5 years) and twenty-five healthy active female collegiate students (mean age 18.1 ± 1.0 years) participated in this study to investigate the effects of dancing exercise on postural stability of adolescent female through a comparison study of two cohorts. The groups were matched in height and weight. Participants were excluded for left-side dominance, sustained lower extremity injury, any known vestibular system dysfunction, uncorrected visual problems, and other neurological conditions. Static and dynamic standing balances were measured by means of Biodex Stability System in six conditions include bilateral, dominant, and nondominant single leg stances with eye-open and eye-closed conditions. To investigate the difference between static and dynamic stabilities, two protocols were performed: the first protocol consisted of four positions including static position, Level 8, Level 4, and Level 1, respectively. They were instructed to maintain a level platform as stably as possible for a period of 30 seconds for each test and given a 30-second rest between tests. The second protocol was descending stability level that was gradually changed from Level 12 to Level 1 for 60 seconds. Balance indices included overall stability index, anterior-posterior stability index (APSI), and medial-lateral stability index. The results of first protocol showed that there were significant differences in overall stability index score between study and control groups at Level 8 with dominant single leg standing in the eye-open condition and the APSI score at Level 8 and at Level 4 with dominant single-leg standing in the eye-closed condition. There was no significant difference in the second protocol. The possible explanation is loss of familiarization adaptation because of level change consequently in both the groups, not step-by-step as in the first protocol study. Furthermore, a positive correlation was

  3. Individual and contextual characteristics as determinants of sagittal standing posture: a population-based study of adults.

    PubMed

    Araújo, Fábio; Lucas, Raquel; Alegrete, Nuno; Azevedo, Ana; Barros, Henrique

    2014-10-01

    Sagittal standing posture is associated with musculoskeletal symptoms and quality of life. However, the frequency and determinants of suboptimal sagittal alignment outside the clinical context remain to be clarified. To estimate the association of sociodemographic, anthropometric, and behavioral characteristics with sagittal standing posture among adults from the general population. Cross-sectional evaluation of a population-based sample. As part of the EPIPorto study, 489 adults were assessed during 2005 to 2008. Individual spinopelvic parameters were measured. Additionally, participants were classified into one of four types of sagittal postural patterns (Roussouly classification: Types 1, 2, and 4 corresponding to nonneutral postures and Type 3 to a neutral posture). Spinopelvic parameters were recorded from 36-inch sagittal radiographs obtained in free-standing posture. Age, sex, education, occupation, body mass index (BMI), waist circumference, total physical activity, leisure time physical activity, time spent in sitting position, smoking status, and tobacco cumulative exposure were collected. Individual parameters and patterns of sagittal posture were compared across categories of participants' characteristics. Older age, lower educational level, blue collar occupation, and overall and central obesity were associated with increased sagittal vertical axis and pelvic tilt/pelvic incidence ratio. Taking the neutral postural pattern (Type 3) as reference for the outcome in a multinomial regression model, independently of age, sex, education, total physical activity, and smoking status, overweight adults had higher odds of Type 2 (odds ratio [OR]=1.92; 95% confidence interval [CI]: 1.13-3.27) and Type 4 (OR=2.13; 95% CI: 1.16-3.91) postural patterns in comparison with normal weight subjects. Overall and central obesity were positively related with Type 1 postural pattern (OR=6.10, 95% CI: 1.52-24.57 and OR=3.54, 95% CI: 1.13-11.11, respectively). There was also a

  4. Perceptual inhibition is associated with sensory integration in standing postural control among older adults.

    PubMed

    Redfern, Mark S; Jennings, J Richard; Mendelson, David; Nebes, Robert D

    2009-09-01

    In older adults, maintaining balance and processing information typically interfere with each other, suggesting that executive functions may be engaged for both. We investigated associations between measures of inhibitory processes and standing postural control in healthy young and older adults. Perceptual and motor inhibition was measured using a protocol adapted from Nassauer and Halperin (2003, Dissociation of perceptual and motor inhibition processes through the use of novel computerized conflict tasks. Journal of the International Neuropsychological Society, 9, 25-30). These measures were then correlated to postural sway during standing conditions that required resolving various levels of sensory conflict, for example, world-fixed versus sway-referenced floor and visual scene. In the older adults, perceptual inhibition was positively correlated with sway amplitude on a sway-referenced floor and with a fixed visual scene (r = .68, p < .001). Motor inhibition was not correlated with sway on either group. Perceptual inhibition may be a component of the sensory integration process important for maintaining balance in older adults.

  5. The impact of localized fatigue on contralateral tremor and muscle activity is exacerbated by standing posture.

    PubMed

    Morrison, S; Sosnoff, J J

    2010-12-01

    Physiological tremor is an inherent feature of the motor system that is influenced by intrinsic (neuromuscular) and/or extrinsic (task) factors. Given that tremor must be accounted for during the performance of many fine motor skills; there is a requirement to clarify how different factors interact to influence tremor. This study was designed to assess the impact localized fatigue of a single arm and stance position had on bilateral physiological tremor and forearm muscle activity. Results demonstrated that unilateral fatigue produced bilateral increases in tremor and wrist extensor activity. For example, fatigue resulted in increases in extensor activity across both exercised (increased 8-10% MVC) and the non-exercised arm (increased 3-7% MVC). The impact of fatigue was not restricted to changes in tremor/EMG amplitude, with altered hand-finger coupling observed within both arms. Within the exercised arm, cross-correlation values decreased (pre-exercise r=0.62-0.64; post-exercise r=0.37-0.43) while coupling increased within the non-exercised arm (pre-exercise r=0.51-0.55; post-exercise r=0.62-0.67). While standing posture alone had no significant impact on tremor/EMG dynamics, the tremor and muscle increases seen with fatigue were more pronounced when standing. Together these results demonstrate that the combination of postural and fatigue factors can influence both tremor/EMG outputs and the underlying coordinative coupling dynamics.

  6. Spinal muscles can create compressive follower loads in the lumbar spine in a neutral standing posture.

    PubMed

    Han, Kap-Soo; Rohlmann, Antonius; Yang, Seok-Jo; Kim, Byeong Sam; Lim, Tae-Hong

    2011-05-01

    The ligamentous spinal column buckles under compressive loads of even less than 100N. Experimental results showed that under the follower load constraint, the ligamentous lumbar spine can sustain large compressive loads without buckling, while at the same time maintaining its flexibility reasonably well. The purpose of this study was to investigate the feasibility of follower loads produced by spinal muscles in the lumbar spine in a quiet standing posture. A three-dimensional static model of the lumbar spine incorporating 232 back muscles was developed and utilized to perform the optimization analysis in order to find the muscle forces, and compressive follower loads (CFLs) along optimum follower load paths (FLPs). The effect of increasing external loads on CFLs was also investigated. An optimum solution was found which is feasible for muscle forces producing minimum CFLs along the FLP located 11 mm posterior to the curve connecting the geometrical centers of the vertebral bodies. Activation of 30 muscles was found to create CFLs with zero joint moments in all intervertebral joints. CFLs increased with increasing external loads including FLP deviations from the optimum location. Our results demonstrate that spinal muscles can create CFLs in the lumbar spine in a neutral standing posture in vivo to sustain stability. Therefore, its application in experimental and numerical studies concerning loading conditions seems to be suitable for the attainment of realistic results. Published by Elsevier Ltd.

  7. Evaluation of a portable media device for use in determining postural stability in standing horses.

    PubMed

    Moorman, Valerie J; Kawcak, Christopher E; King, Melissa R

    2017-09-01

    OBJECTIVE To determine the ability of an accelerometer within a commercially available portable media device (PMD) to measure changes in postural stability of standing horses during various stance conditions and to compare these results with data obtained by use of a stationary force platform. ANIMALS 7 clinically normal horses. PROCEDURES A PMD was mounted on a surcingle; the surcingle was placed immediately caudal to the highest point of the shoulders (withers). Each horse was examined while standing on a stationary force platform system in a normal square stance, forelimb base-narrow stance, and normal square stance at 5 and 10 minutes after sedation induced by IV administration of xylazine hydrochloride. A minimum of 5 trials were conducted for each stance condition. Ranges of craniocaudal and mediolateral motion as well as SDs were collected for the PMD and force platform system. Analyses were performed with mixed-model ANOVAs, and correlation coefficients were calculated. RESULTS Stance condition significantly altered craniocaudal accelerations measured by use of the PMD, all craniocaudal and mediolateral displacements of the center of pressure, and velocities measured by use of the stationary force platform. For both the PMD and force platform, SDs were significantly affected by stance condition in both craniocaudal and mediolateral directions. Correlation coefficients between the systems for all variables were low to moderate (r = 0.18 to 0.58). CONCLUSIONS AND CLINICAL RELEVANCE Body-mounted PMDs should be investigated for use in assessment of postural stability in horses with neuromuscular abnormalities.

  8. Automated reconstruction of standing posture panoramas from multi-sector long limb x-ray images

    NASA Astrophysics Data System (ADS)

    Miller, Linzey; Trier, Caroline; Ben-Zikri, Yehuda K.; Linte, Cristian A.

    2016-03-01

    Due to the digital X-ray imaging system's limited field of view, several individual sector images are required to capture the posture of an individual in standing position. These images are then "stitched together" to reconstruct the standing posture. We have created an image processing application that automates the stitching, therefore minimizing user input, optimizing workflow, and reducing human error. The application begins with pre-processing the input images by removing artifacts, filtering out isolated noisy regions, and amplifying a seamless bone edge. The resulting binary images are then registered together using a rigid-body intensity based registration algorithm. The identified registration transformations are then used to map the original sector images into the panorama image. Our method focuses primarily on the use of the anatomical content of the images to generate the panoramas as opposed to using external markers employed to aid with the alignment process. Currently, results show robust edge detection prior to registration and we have tested our approach by comparing the resulting automatically-stitched panoramas to the manually stitched panoramas in terms of registration parameters, target registration error of homologous markers, and the homogeneity of the digitally subtracted automatically- and manually-stitched images using 26 patient datasets.

  9. Do individuals who develop transient low back pain exhibit different postural changes than non-pain developers during prolonged standing?

    PubMed

    Gallagher, Kaitlin M; Nelson-Wong, Erika; Callaghan, Jack P

    2011-10-01

    Previous literature has shown that individuals can develop transient low back pain (LBP) during a 2-h bout of unconstrained prolonged standing. The purpose of this study was to investigate the postural changes of individuals who develop LBP during standing (PD) and those who do not (NPD). Forty-one subjects (20 male, 21 female) participated in a 2-h prolonged standing occupational simulation and recorded their ratings of perceived LBP on a visual analog scale (VAS). Center of pressure changes (shifts, drifts, and fidgets) and body weight shifts were determined for each subject. All subjects showed an increase in the BW shift frequency and a decrease in average shift duration over the 2-h protocol. All NPD and female PD were consistent for many of the variables; however, male PD did not show similar patterns to the other groups, especially for anterior-posterior (AP) shift amplitude and total body weight asymmetry. Although gender differences between the pain groups were found, PD and NPD do not use different postural changes during unconstrained standing, showing that changes to postural control may be an "adaptive", rather than "causative" response to their LBP development. Future works should concentrate on bridging the literature seen in quiet standing before and after prolonged standing and the response of PD, as well as the effect of an exercise intervention on postural control, especially for male PD. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Changes of the body posture parameters in the standing versus relaxed sitting and corrected sitting position.

    PubMed

    Drzaƚ-Grabiec, Justyna; Truszczyńska, Aleksandra; Fabjańska, Maƚgorzata; Trzaskoma, Zbigniew

    2016-04-27

    Decrease of physiological curvatures of the spine can lead to back pain. The aim of this study was to compare the curvatures of the spine and body posture parameters in three positions: relaxed standing, relaxed sitting, corrected sitting. The study included 40 healthy persons aged 18-32 years (mean 24.7 ± 2.3), with body height 152-195 cm (mean 171.8 ± 9.3), weight 47-115 kg (mean 66.4 ± 13.7), BMI 17.9-32.5 kg/m2 (mean 22.3 ± 3.0). The study was performed using the photogrammetric method. After changing the position from relaxed standing to relaxed sitting, significant decrease of the inclination of the thoracolumbar region, the thoracic kyphosis depth and the lumbar lordosis depth were observed. Lumbar lordosis angle increased significantly. After the sitting position correction, the inclination of the upper thoracic and thoracolumbar region decreased, and the depth of thoracic kyphosis and lumbar lordosis increased. - In the relaxed sitting position, the lumbar lordosis was significantly smaller than in the standing position. - A change from the standing to the sitting position results in flattening of thoracic kyphosis. - The corrected sitting position does not adequately correct the spinal curvatures.

  11. A novel approach in objective assessment of functional postural responses during fall-free perturbed standing in clinical environment.

    PubMed

    Cikajlo, Imre; Matjacsić, Zlatko

    2007-01-01

    The proposed approach offers few novelties in integration of objective assessment of postural responses when an unexpected perturbation is applied to the standing person into the existing rehabilitation therapy. The research apparatus was equipped with electrical actuators to provide unexpected perturbations (controllable and repeatable strength and duration) to the standing frame in eight directions during quiet standing in a fall-safe environment. During the perturbations ground reaction forces were recorded under each foot and the motion of center of pressure was derived to extract the postural response indicators in time and space domain. Seven neurologically intact subjects participated in normative set up that was used to develop an algorithm for selective postural response characteristics analysis for each perturbation direction. The postural responses in two incomplete spinal cord injured persons and hemiparetic stroke patient were investigated and contrasted to the normative responses to test the proposed approach. The outcomes of the investigation showed expected distinctive direction-dependent postural responses characteristic for hemiparetic subjects. Our observations suggest that the approach may become effective in substantial quantitative multidirectional stabilometric evaluation of functional postural responses, especially when the effectiveness of the balance training rehabilitation program is in need for objective evaluation. Simultaneously the apparatus can be used also for the balance training and therefore become a training and assessment tool for clinical and home environment.

  12. Association of biopsychosocial factors with degree of slump in sitting posture and self-report of back pain in adolescents: a cross-sectional study.

    PubMed

    O'Sullivan, Peter B; Smith, Anne J; Beales, Darren J; Straker, Leon M

    2011-04-01

    Conflicting evidence exists regarding relationships among sitting posture, factors that influence sitting posture, and back pain. This conflicting evidence may partially be due to the presence of multiple and overlapping factors associated with both sitting posture and back pain. The purpose of this study was to determine whether the degree of slump in sitting was associated with sex and other physical, lifestyle, or psychosocial factors. Additionally, the relationship between the report of back pain made worse by sitting and the degree of slump in sitting and other physical, lifestyle, or psychosocial factors was investigated. This was a cross-sectional study. Adolescents (n=1,596) completed questionnaires to determine lifestyle and psychosocial profiles and the experience of back pain. Sagittal sitting posture, body mass index (BMI), and back muscle endurance (BME) were recorded. Standing posture subgroup categorization was determined. Multivariate analysis revealed that the most significant factor associated with the degree of slump in sitting was male sex, followed by non-neutral standing postures, lower perceived self-efficacy, lower BME, greater television use, and higher BMI. Multivariable analysis indicated poorer Child Behaviour Checklist scores were the strongest correlate of report of back pain made worse by sitting, whereas degree of slump in sitting, female sex, and BME were more weakly related. Causality cannot be determined from this cross-sectional study, and 60% of sitting posture variation was not explained by the measured variables. Slump in sitting was associated with physical correlates, as well as sex, lifestyle, and psychosocial factors, highlighting the complex, multidimensional nature of usual sitting posture in adolescents. Additionally, this study demonstrated that a greater degree of slump in sitting was only weakly associated with adolescent back pain made worse by sitting after adjustment for other physical and psychosocial factors.

  13. Universal and individual characteristics of postural sway during quiet standing in healthy young adults

    PubMed Central

    Yamamoto, Tomohisa; Smith, Charles E; Suzuki, Yasuyuki; Kiyono, Ken; Tanahashi, Takao; Sakoda, Saburo; Morasso, Pietro; Nomura, Taishin

    2015-01-01

    The time course of the center of pressure (CoP) during human quiet standing, corresponding to body sway, is a stochastic process, influenced by a variety of features of the underlying neuro-musculo-skeletal system, such as postural stability and flexibility. Due to complexity of the process, sway patterns have been characterized in an empirical way by a number of indices, such as sway size and mean sway velocity. Here, we describe a statistical approach with the aim of estimating “universal” indices, namely parameters that are independent of individual body characteristics and thus are not “hidden” by the presence of individual, daily, and circadian variations of sway; in this manner it is possible to characterize the common aspects of sway dynamics across healthy young adults, in the assumption that they might reflect underlying neural control during quiet standing. Such universal indices are identified by analyzing intra and inter-subject variability of various indices, after sorting out individual-specific indices that contribute to individual discriminations. It is shown that the universal indices characterize mainly slow components of sway, such as scaling exponents of power-law behavior at a low-frequency regime. On the other hand, most of the individual-specific indices contributing to the individual discriminations exhibit significant correlation with body parameters, and they can be associated with fast oscillatory components of sway. These results are consistent with a mechanistic hypothesis claiming that the slow and the fast components of sway are associated, respectively, with neural control and biomechanics, supporting our assumption that the universal characteristics of postural sway might represent neural control strategies during quiet standing. PMID:25780094

  14. Postural response latencies are related to balance control during standing and walking in patients with multiple sclerosis

    PubMed Central

    Huisinga, Jessie M.; St. George, Rebecca J.; Spain, Rebecca; Overs, Shannon; Horak, Fay B.

    2015-01-01

    Objective To understand examined the relationship between postural response latencies obtained during postural perturbations and representative measures of balance during standing (sway variables) and during walking (trunk motion). Design Cross-sectional Setting University medical center balance disorders laboratory Participants Forty persons with MS were compared with 20 similar aged control subjects. Twenty subjects with MS had normal walking velocity group and 20 had slow walking velocity based on the 25-foot walk time greater than 5 seconds. Interventions None Main Outcome Measures Postural response latency, sway variables, trunk motion variables Results: We found that subjects with MS with either slow or normal walking velocities had significantly longer postural response latencies than the healthy control group. Postural response latency was not correlated with the 25-ft walk time. Postural response latency was significantly correlated with center of pressure sway variables during quiet standing: root mean square (ρ = 0.334, p=0.040), range (ρ=0.385, p=0.017), mean velocity (ρ=0.337, p=0.038), and total sway area (ρ=0.393, p=0.015). Postural response latency was also significantly correlated with motion of the trunk during walking: sagittal plane range of motion (ρ=0.316, p=0.050) and standard deviation of transverse plane range of motion (ρ=-0.430, p=0.006). Conclusions These findings clearly indicate that slow postural responses to external perturbations in patients with MS contribute to disturbances in balance control, both during standing and walking. PMID:24445088

  15. Sagittal standing posture, back pain, and quality of life among adults from the general population: a sex-specific association.

    PubMed

    Araújo, Fábio; Lucas, Raquel; Alegrete, Nuno; Azevedo, Ana; Barros, Henrique

    2014-06-01

    A prospective radiographical study of sagittal standing posture among adults consecutively recruited from the general population. To analyze the relation of suboptimal sagittal standing posture with back pain and health-related quality of life in general adult males and females. Clinical studies have shown the association of sagittal standing posture with pain and reduced quality of life, but this relation has not been assessed in the general adult population. As part of the EPIPorto population-based study of adults, 178 males and 311 females were evaluated. Age, education, and body mass index were recorded. Radiographical data collection consisted of 36-in. standing sagittal radiographs. Creation of 3 groups for individual spinopelvic parameters was performed (low, intermediate, or high), and 1 of 4 sagittal types of postural patterns attributed to each participant (Roussouly classification). Back pain prevalence and severity were assessed on the basis of self-reported data and health-related quality of life using 2 main components of the 36-Item Short Form Health Survey. In males, differences in back pain severity were observed only among pelvic tilt/pelvic incidence ratio groups. Females presenting high pelvic incidence and sacral slope exhibited higher odds of severe back pain than those with intermediate values (adjusted odds ratios = 2.21 and 2.15; 95% confidence interval, 1.24-3.97 and 1.21-3.86; respectively). Sagittal vertical axis showed the largest differences in physical quality of life of females: high group had 8.8 lower score than the low group (P < 0.001), but this result lost statistical significance after adjustment for age, education, and body mass index. Sagittal standing posture was not consistently associated with quality of life measures in males. Increased pelvic incidence and sacral slope may be involved in causing severe back pain among females. Monitoring sagittal postural parameters has limited usefulness as a screening tool for causes

  16. Body metabolic rate and electromyographic activities of antigravitational muscles in supine and standing postures.

    PubMed

    Rubini, Alessandro; Paoli, Antonio; Parmagnani, Andrea

    2012-06-01

    We measured metabolic (oxygen uptake, carbon dioxide production, respiratory ratio), cardio-circulatory (heart rate, systolic and diastolic arterial blood pressure, rate-pressure product, an index of myocardial oxygen consumption calculated by multiplying heart rate by systolic pressure) and electromyographic (integrated electromyographic activities of two antigravitational muscles of the lower limb, soleus and gastrocnemius) variables on 12 young healthy subjects in supine and standing positions at rest. We found statistically significant increments of oxygen uptake, carbon dioxide production, heart rate and integrated electromyographic activities in standing versus supine position. Rate-pressure product increased but not significantly, and no other significant changes were detected. We conclude that postural changes influence metabolic rate, antigravitational muscle reflex activities, and heart rate. A significant positive correlation was found between oxygen uptake and carbon dioxide production and integrated electromyographic activities of antigravitational muscles, while the same was not found for cardio-circulatory variables. These results suggest that the increased metabolic rate in standing position is, at least in part, due to antigravitational muscle tone.

  17. Studying the relationship between low back pain and working postures among those who stand and those who sit most of the working day.

    PubMed

    Tissot, F; Messing, K; Stock, S

    2009-11-01

    A relationship between low back pain (LBP) and prolonged standing or prolonged sitting at work has not been clearly shown, despite its biological plausibility. Because sitting and standing postures vary as to duration and freedom to alternate postures, and standing postures vary as to mobility, associations between specific working postures and LBP were explored using multiple logistic regression. Associations between work factors and self-reported LBP during the previous 12 months that interfered with usual activities were examined among 4493 standing workers and 3237 sitting workers interviewed in the 1998 Quebec Health and Social Survey; 24.5% reported significant LBP. Since the same conditions can correspond to different physiological demands for sitting compared with standing workers, analyses were performed separately for the two groups. Standing without freedom to sit was associated with LBP. Different occupational physical and psychosocial factors were associated with LBP in sitting compared with standing populations.

  18. Is head-on-trunk extension a proprioceptive mediator of postural control and sit-to-stand movement characteristics?

    PubMed

    Johnson, Molly B; Van Emmerik, Richard E A

    2011-01-01

    During stance, head extension increases postural sway, possibly due to interference with sensory feedback. The sit-to-stand movement is potentially destabilizing due to the development of momentum as the trunk flexes forward and the body transitions to a smaller base of support. It is unclear what role head orientation plays in the postural and movement characteristics of the sit-to-stand transition. The authors assessed how moving from sitting to standing with head-on-trunk extension compared with moving with the head neutral or flexed, or with moving with the head facing forward in space (which would involve head-on-trunk extension, but not head-in-space extension) in healthy, young participants. Head-on-trunk extension increased center of pressure variability, but decreased movement velocities, movement duration, and trunk flexion compared with flexed and neutral head-on-trunk orientations. Similarities in movement characteristics between head-on-trunk extension and the forward head-in-space orientation suggest that stabilizing the head in space does not fully counteract the postural and movement changes due to head-on-trunk extension. Findings suggest that proprioceptive feedback from the neck muscles contributes to the regulation of posture and movement, and therefore should not be overlooked in research on the role of sensory feedback in postural control.

  19. Posture management program based on theory of planned behavior for adolescents with mild idiopathic scoliosis.

    PubMed

    Choi, Jihea; Kim, Hee Soon; Kim, Gwang Suk; Lee, Hyejung; Jeon, Hye-Seon; Chung, Kyong-Mee

    2013-09-01

    The purpose of this study was to evaluate the effects of a devised posture management program based on the Theory of Planned Behavior in adolescents with mild idiopathic scoliosis. A quasi-experimental study was conducted. It involved a nonequivalent comparison group design with pretest and posttest. Forty-four female adolescents with mild idiopathic scoliosis participated; data from 35 participants (20 for the test group, 15 for the control group) were used for the final analyses. The devised posture management program ran for 6 weeks. Posture management behavioral determinants (attitude, subjective norms, perceived behavioral control, and behavioral intention) as cognitive outcomes and muscular strength and flexibility as physical outcomes were measured three times: at baseline, week 6 and week 8. Cobb's angle as another physical outcome was measured twice: at baseline and week 8. Descriptive analysis, repeated measures analysis of variance and t test were used for data analyses. Attitude, perceived control, and behavioral intention were consistently enhanced by the posture management program. The intervention increased flexibility and muscular strength and decreased Cobb's angle, which reduced spinal curvature. Frequency of posture management exercise showed a gradual increase in the test group. The results indicate that the posture management program is effective in maintaining posture management behavior in adolescents with mild idiopathic scoliosis for both cognitive and physical outcomes. The posture management program should be helpful in expanding the role of school nurses in improving the health status of adolescents with mild idiopathic scoliosis. Copyright © 2013. Published by Elsevier B.V.

  20. Sex differences in the postural sway characteristics of young and elderly subjects during quiet natural standing.

    PubMed

    Kim, Ji-Won; Eom, Gwang-Moon; Kim, Chul-Seung; Kim, Da-Hye; Lee, Jae-Ho; Park, Byung Kyu; Hong, Junghwa

    2010-04-01

    It has been reported that the fall incidence in women is much higher than men and that fallers have worse postural balance performance than non-fallers. However, it is controversial whether any sex difference in postural balance performance exists. The purpose of this study was to investigate the effects of sex and age and their interactions in balance performance during quiet standing with natural stance width. Sixty-three elderly subjects (aged 65-86 years) and 66 young subjects (aged 18-26 years) performed quiet standing with self-selected natural feet distance on a force plate. Four analysis variables - mean distance, mean velocity, 95% power frequency and total power - were derived from the center of pressure (COP) and they were evaluated both in anteroposterior and mediolateral directions. In anteroposterior direction, no sex effect and interaction existed, however, all variables except mean distance showed significant age effects (P < 0.01). In contrast, mediolateral direction variables showed significant sex effect where women had greater but less frequent COP movement than men (P < 0.01). Interactions of age and sex were also significant in mediolateral direction, where age-related changes were significant only in women so that sex differences (faster COP movement with more total power in women than men) existed only in the elderly (P < 0.01) but not in the young. The sex difference in balance performance (some of which are significant only in the elderly) and the sex difference in age-related change of balance performance were demonstrated in mediolateral direction. These sex differences may contribute to the sex difference in balance-related problems, such as falls.

  1. Thoracic and lumbar posture behaviour in sitting tasks and standing: Progressing the biomechanics from observations to measurements.

    PubMed

    Claus, Andrew P; Hides, Julie A; Moseley, G Lorimer; Hodges, Paul W

    2016-03-01

    Few studies quantify spinal posture behaviour at both the thoracolumbar and lumbar spinal regions. This study compared spontaneous spinal posture in 50 asymptomatic participants (21 males) during three conditions: 10-min computer task in sitting (participants naïve to the measure), during their perceived 'correct' sitting posture, and standing. Three-dimensional optical tracking quantified surface spinal angles at the thoracolumbar and lumbar regions, and spinal orientation with respect to the vertical. Despite popular belief that lordotic lumbar angles are 'correct' for sitting, this was rarely adopted for 10-min sitting. In 10-min sitting, spinal angles flexed 24(7-9)deg at lumbar and 12(6-8)deg at thoracolumbar regions relative to standing (P < 0.001). When participants 'corrected' their sitting posture, their thoracolumbar angle -2(7)deg was similar to the angle in standing -1(6)deg (P = 1.00). Males were flexed at the lumbar angle relative to females for 10-min sitting, 'correct' sitting and standing, but showed no difference at the thoracolumbar region.

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

    PubMed Central

    O’Brien, Megan K.

    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. PMID:25083345

  3. Hands Support and Postural Oscillation During Sit-to-Stand Movement in Children With Cerebral Palsy and Typical Children.

    PubMed

    Pavão, Silvia Leticia; Rocha, Nelci Adriana Cicuto Ferreira

    2017-06-23

    The authors aimed to compare the weight bearing on hands during sit-to-stand (STS) movement in children with cerebral palsy (CP) and typical children (TC), verify its effect on postural oscillation, and analyze the relationship between weight bearing on hands and postural oscillation. Twenty children with CP (Gross Motor Function Classification System levels I and II) and 35 TC performed STS with and without anterior hands support. Mann-Whitney test compared weight bearing between groups. Wilcoxon test investigated differences in postural oscillation between the conditions with and without anterior hand support for both groups. The Spearman correlation tested the relationship between weight-bearing and postural oscillation during the hand support condition. Children with CP bore more weight on hands than TC to perform STS. The hand support reduced postural oscillation during the second phase of STS in both groups. In the CP group, greater weight bearing was related with lower postural oscillation in the beginning of STS. Although children with CP were able to perform STS without support, they bore more weight on their hands to perform the task than TC. Moreover, children with CP and TC use mechanical and somatosensory information to modulate their postural control during STS in different ways.

  4. Lower extremity preference during gross and fine motor skills performed in sitting and standing postures.

    PubMed

    Beling, J; Wolfe, G A; Allen, K A; Boyle, J M

    1998-12-01

    The evaluation of lower limb preference in physical therapy practice is critical in order for the clinician to assist patients with functional retraining tasks. No studies in the physical therapy literature present a systematic approach to determine the criteria needed to identify the preferred limb. This research was designed to present a series of tests for effectiveness in determining limb preference. The purpose of this study was to determine whether lower limb preference existed in a group of recreationally athletic women when performing either stability or dynamic skills with the lower extremities while sitting or standing. The relationship of such a preference to handedness was also determined. Forty female recreational athletes, 20 right-handed subjects and 20 left-handed subjects, who ranged in age from 21 to 35 years, participated in this study. Subjects performed three repetitions of the following tests in both sitting and standing: kick a ball, swing a leg over a box, pick up a marble with the toes, and trace a triangle with the toes. The subjects were also asked to stand on one leg. The order of performing the tests was randomized. The results indicated that right-handed subjects performed activities more consistently with one lower extremity when compared with left-handed subjects, regardless of posture (sitting or standing). The difference in limb choice between right- and left-handed subjects was significant for all activities (p < .05). The considerable sensitivity of foot and leg performance following neurological insult renders the assessment of foot and leg preference very important for purposes of clinical rehabilitation.

  5. Impaired Postural Control Reduces Sit-to-Stand-to-Sit Performance in Individuals with Chronic Obstructive Pulmonary Disease

    PubMed Central

    Janssens, Lotte; Brumagne, Simon; McConnell, Alison K.; Claeys, Kurt; Pijnenburg, Madelon; Goossens, Nina; Burtin, Chris; Janssens, Wim; Decramer, Marc; Troosters, Thierry

    2014-01-01

    Background Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to the decreased STSTS performance in individuals with COPD. Methods Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each sit, sit-to-stand, stand and stand-to-sit phase was recorded. Results Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (19±6 vs. 13±4 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups. Conclusions Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD. PMID:24533072

  6. Assessment of the posture of adolescents in everyday clinical practice: Intra-rater and inter-rater reliability and validity of a posture index.

    PubMed

    Ludwig, Oliver; Hammes, Annette; Kelm, Jens; Schmitt, Eduard

    2016-10-01

    The assessment of the posture of children and adolescents using photometric methods has a long tradition in paediatrics, manual therapy and physiotherapy. It can be well integrated into the clinical routine and enables objective documentation. One-dimensional parameters such as angle sizes are mostly used in the diagnosis of postural defects in children and adolescents by means of photogrammetry. This study examined the posture index, a complex parameter, which evaluates the alignment of several trunk segments in the sagittal plane and is suitable for use as a screening parameter in everyday clinical practice. For this postural photographs were taken in the sagittal plane of the habitual posture in a subgroup of 105 adolescents (12.9 ± 2.6 years) for analysing validity, and in a subgroup of 25 adolescents (12.1 ± 2.8 years) for analysing reliability and objectivity. Marker spheres (12 mm) were placed on five anatomical landmarks. The posture was also evaluated clinically by experienced investigators (PT, MD, DSc). The distances of the marker points to the plumb line through the malleolus lateralis were calculated and the posture index calculated from these. In order to determine the objectivity, reliability and validity of the posture index, statistical parameters were calculated. The posture index demonstrated very good objectivity (intraclass correlation coefficient ICC = 0.865), good reliability (Cronbach's alpha = 0.842) and good validity compared to the posture assessment done by the medical experts (Spearman's rho = 0.712). The posture index reflects a doctor's assessment of the posture of children and adolescents and is suitable as a clinical parameter for the assessment of postural defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Neck muscle endurance and head posture: A comparison between adolescents with and without neck pain.

    PubMed

    Oliveira, Ana Carolina; Silva, Anabela G

    2016-04-01

    The main aims of this study were to compare the neck flexor and extensor endurance and forward head posture between adolescents with and without neck pain. The secondary aims were to explore potential associations between muscles endurance, head posture and neck pain characteristics and to assess intra-rater reliability of the measurements used. Adolescents with neck pain (n = 35) and age-matched asymptomatic adolescents (n = 35) had their forward head posture, neck flexor endurance and neck extensor endurance measured using clinical tests. Intra-rater reliability was also assessed. Forward head posture and neck flexor and extensor endurance tests showed moderate to almost perfect intra-rater reliability (ICC between 0.58 and 0.88). Adolescents with neck pain showed significantly less forward head posture (neck pain = 46.62 ± 4.92; asymptomatic = 44.18°± 3.64°, p > 0.05) and less neck flexor (neck pain = 24.50 ± 23.03s; asymptomatic = 35.89 ± 21.53s, p > 0.05) and extensor endurance (neck pain = 12.6.64 ± 77.94s; asymptomatic = 168.66 ± 74.77s, p > 0.05) than asymptomatic adolescents. Results suggest that changes in posture and neck muscle endurance are a feature of adolescents with neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Association of force steadiness of plantar flexor muscles and postural sway during quiet standing by young adults.

    PubMed

    Oshita, Kazushige; Yano, Sumio

    2012-08-01

    This study was conducted to assess the relations of force fluctuations during isometric plantar-flexion and postural sway during quiet standing. Twelve healthy men (M age = 21 yr., SD = 1) performed unilateral plantar flexion measured by a strain gauge force transducer. Participants performed force-matching tasks; sustained plantar flexion for 20 sec. at levels corresponding to 10% and 20% of maximum voluntary contraction with the visual feedback. Also, participants were asked to stand quietly with their eyes open, and then the center of mass displacement and velocity in the anteroposterior were measured. In analysis, postural sway was associated with force fluctuation at only 10% of maximum voluntary contraction. The statistically significant correlation between variables was found only at corresponding contraction intensities for plantar-flexor muscles. From this one may infer neural strategies in plantar-flexor muscles during quiet standing may be characteristics similar to those controlling the plantar-flexion force in young adults.

  9. Inclination of standing posture due to the presentation of tilted view through an immersive head-mounted display

    PubMed Central

    Ohmura, Yuji; Yano, Shiro; Katsuhira, Junji; Migita, Masato; Yozu, Arito; Kondo, Toshiyuki

    2017-01-01

    [Purpose] The purpose of the present study is to clarify whether tilted scenery presented through an immersive head-mounted display (HMD) causes the inclination of standing posture. [Subjects and Methods] Eleven healthy young adult males who provided informed consent participated in the experiment. An immersive HMD and a stereo camera were employed to develop a visual inclination system. The subjects maintained a standing posture twice for 5s each while wearing the visual inclination system. They performed this task under two conditions: normal view and 20° leftward tilted view. A three-dimensional motion analysis system was used to measure the subjects’ postures, and two force plates were used to measure the vertical component of the floor reaction force of each leg. [Results] In the 20° leftward tilted view, the head and trunk angles in the frontal plane were similarly inclined toward the left, and the vertical component of the floor reaction force increased in the left leg, whereas it decreased in the right leg. [Conclusion] When the view in the immersive HMD was tilted, the participants’ trunk side bent toward the same side as that of the view. This visual inclination system seems to be a simple intervention for changing standing posture. PMID:28265145

  10. A Quiet Standing Index for Testing the Postural Sway of Healthy and Diabetic Adults Across a Range of Ages

    PubMed Central

    Bollt, Erik M.; Fulk, George D.; Skufca, Joseph D.; Al-Ajlouni, Ahmad F.; Robinson, Charles J.

    2010-01-01

    A quietstanding index is developed for tracking the postural sway of healthy and diabetic adults over a range of ages. Several postural sway features are combined into a single composite feature C that increases with age a. Sway features are ranked based on the r2 -values of their linear regression models, and the composite feature is a weighted sum of selected sway features with optimal weighting coefficients determined using principal component analysis. A performance index based on both reliability and sensitivity is used to determine the optimal number of features. The features used to form C include power and distance metrics. The quiet standing index is a scalar that compares the composite feature C to a linear regression model f (a) using C′ (a) = C/f (a). For a motionless subject, C′ = 0, and when the composite feature exactly matches the healthy control (HC) model, C′ = 1. Values of C′ ≫ 1 represent excessive postural sway and may indicate impaired postural control. Diabetic neurologically intact subjects, nondiabetic peripheral neuropathy subjects (PN), and diabetic PN subjects (DPN) were evaluated. The quiet standing indexes of the PN and DPN groups showed statistically significant increases over the HC group. Changes in the quiet standing index over time may be useful in identifying people with impaired balance who may be at an increased risk of falling. PMID:19342327

  11. Early Adolescent Romantic Partner Status, Peer Standing, and Problem Behaviors

    ERIC Educational Resources Information Center

    Miller, Shari; Lansford, Jennifer E.; Costanzo, Philip; Malone, Patrick S.; Golonka, Megan; Killeya-Jones, Ley A.

    2009-01-01

    This study examined associations among early adolescent romantic relationships, peer standing, problem behaviors, and gender as a moderator of these associations, in a sample of 320 seventh-grade students. Popular and controversial status youth were more likely to have a romantic partner, whereas neglected status youth were less likely to have a…

  12. Early Adolescent Romantic Partner Status, Peer Standing, and Problem Behaviors

    ERIC Educational Resources Information Center

    Miller, Shari; Lansford, Jennifer E.; Costanzo, Philip; Malone, Patrick S.; Golonka, Megan; Killeya-Jones, Ley A.

    2009-01-01

    This study examined associations among early adolescent romantic relationships, peer standing, problem behaviors, and gender as a moderator of these associations, in a sample of 320 seventh-grade students. Popular and controversial status youth were more likely to have a romantic partner, whereas neglected status youth were less likely to have a…

  13. Human standing posture: multi-joint movement strategies based on biomechanical constraints.

    PubMed

    Kuo, A D; Zajac, F E

    1993-01-01

    We developed a theoretical framework for studying coordination strategies in standing posture. The framework consists of a musculoskeletal model of the human lower extremity in the sagittal plane and a technique to visualize, geometrically, how constraints internal and external to the body affect movement. The set of all feasible accelerations (i.e., the "feasible acceleration set" or FAS) that muscles can induce at positions near upright were calculated. We found that musculoskeletal mechanics dictate that independent control of joints is relatively difficult to achieve. When muscle activations are constrained so the knees stay straight, to approximate the typical postural response to perturbation, the corresponding subset of the feasible acceleration set greatly favors a combination of ankle and hip movement in the ratio 1:3 (called the "hip strategy"). Independent control of these two joints remains difficult to achieve. When near the boundary of instability, the orientation and shape of this subset show that the movement strategy necessary to maintain stability, without taking a step, is quite restricted. Hypothesizing that regulation of center-of-mass position is crucial to maintaining balance, we examined the feasible set of center-of-mass accelerations. When the knees must be kept straight, the acceleration of the center of mass is severely limited vertically, but not horizontally. We also found that the "ankle strategy", involving rotation about the ankles only, requires more muscle activation than the "hip strategy" for a given amount of horizontal acceleration. Our model therefore predicts that the hip strategy is most effective at controlling the center of mass with minimal muscle activation ("neural effort").

  14. Changes in Habitual and Active Sagittal Posture in Children and Adolescents with and without Visual Input – Implications for Diagnostic Analysis of Posture

    PubMed Central

    Mazet, Carola; Mazet, Dirk; Hammes, Annette; Schmitt, Eduard

    2016-01-01

    Introduction Poor posture in children and adolescents has a prevalence of 22-65% and is suggested to be responsible for back pain. To assess posture, photometric imaging of sagittal posture is widely used, but usually only habitual posture positions (resting position with minimal muscle activity) are analysed. Aim The objective of this study was 1) to investigate possible changes in posture-describing parameters in the sagittal plane, when the subjects changed from a habitual passive posture to an actively corrected posture, and 2) to investigate the changes in posture parameters when an actively corrected posture was to be maintained with closed eyes. Materials and Methods In a group of 216 male children and adolescents (average 12.4 ± 2.5 years, range 7.0 – 17.6 years), six sagittal posture parameters (body tilt BT, trunk incline TI, posture index PI, horizontal distances between ear, shoulder and hip and the perpendicular to the ankle joint) were determined by means of photometric imaging in an habitual passive posture position, in an actively erect posture with eyes open, and in active stance with eyes closed. The change in these parameters during the transition between the posture positions was analysed statistically (dependent t-Test or Wilcoxon-Test) after Bonferroni correction (p<0.004). Results When moving from a habitual passive to an active posture BT, TI, PI, dEar, dShoulder, and dHip decreased significantly(p< 0.004). When the eyes were closed, only the perpendicular distances (dEar, dShoulder, and dHip) increased significantly. The parameters that describe the alignment of the trunk sections in relation to each other (BT, TI, PI), remained unchanged in both actively regulated posture positions. Conclusion Changes in sagittal posture parameters that occur when a habitual passive posture switches into an active posture or when an active posture is to be maintained while the eyes are closed can be used for diagnostic purposes regarding poor posture

  15. Simulating the restoration of standing balance at leaning postures with functional neuromuscular stimulation following spinal cord injury.

    PubMed

    Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J

    2016-01-01

    In this simulation study, we present and examine methods to develop a feedback controller for a neuroprosthesis that restores forward and side leaning function during standing following complete thoracic-level spinal cord injury. Achieving leaning postures away from erect stance with functional neuromuscular stimulation (FNS) would allow users to extend their reaching capabilities. Utilizing a 3-D computer model of human stance, an FNS control system based on total-body center of mass (CoM) kinematics (position, acceleration) is developed and tested in simulation. CoM kinematics drive an artificial neural network to modulate muscle excitations and reduce the upper extremity loading, presumably against a walker or similar support surface, required to resist the effects of postural perturbations. Furthermore, a novel method to robustly estimate the feedback kinematics for standing applications is also presented while assuming 3-D accelerometer signals at locations consistent with a proposed implantable networked neuroprosthesis system. For shifting and balance at leaning postures, respectively, center of mass position and acceleration could be approximated to within 20% of the maximum value, with strong correlations (R > 0.9) between values estimated by the proposed method and the true values derived from model dynamics. When utilizing the estimated feedback kinematics for FNS control, standing performance in terms of maximum upper extremity loading was still significantly reduced (p < 0.001) compared to conventionally applying constant and maximal stimulation. In the future, these simulation-based methods will be employed to develop experimental approaches for restoring leaning standing function by FNS.

  16. Risk Factors for Postural Tachycardia Syndrome in Children and Adolescents

    PubMed Central

    Li, Xueying; Ochs, Todd; Zhao, Juan; Zhang, Xi; Yang, Jinyan; Liu, Ping; Xiong, Zhenyu; Gai, Yong; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2014-01-01

    Background Postural tachycardia syndrome (POTS) is prevalent in children and adolescents and has a great impact on health. But its risk factors have not been fully understood. This study aimed to explore possible risk factors for children and adolescents with POTS. Methods and Findings 600 children and adolescents (test group) aged 7–18 (11.9±3.0) years old, 259 males and 341 females, were recruited for identifying its risk factors. Another 197 subjects aged from 7 to 18 (11.3±2.3) years old were enrolled in the validation group. Heart rate (HR) and blood pressure (BP) were monitored during upright test. Risk factors were analyzed and sensitivity and specificity for predicting POTS were tested via receiver operating characteristic curve. Among 600 subjects, 41 were confirmed with POTS patients (6.8%) based on clinical manifestation and upright test. The results showed a significant difference in daily water intake, the daily sleeping hours, supine HR, HR increment and maximum HR during upright test between POTS and the unaffected children (P<0.05). Likelihood of POTS would increase by 1.583 times if supine HR was increased by 10 beats/min (95%CI 1.184 to 2.116, P<0.01), by 3.877 times if a child's water intake was less than 800 ml/day (95%CI 1.937 to 7.760, P<0.001), or by 5.905 times (95%CI 2.972 to 11.733, P<0.001) if sleeping hours were less than 8 hours/day. Supine HR, daily water intake and sleeping hours showed the capability of predicting POTS in children and adolescents with an AUC of 83.9% (95% CI: 78.6%–89.1%), sensitivity of 80.5% and specificity of 75%. Furthermore, in validation group, predictive sensitivity and specificity were 73.3% and 72.5%. Conclusion Faster supine HR, less water intake and shorter sleeping hours were identified as risk factors for POTS. PMID:25474569

  17. The effect of foam surface properties on postural stability assessment while standing.

    PubMed

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

    2008-11-01

    A common assessment of postural control often involves subjects standing on a compliant surface, such as a foam block, to make balance tests more challenging. However, the physical properties of the foam block used by different researchers can vary considerably. The objective of this study was to provide an initial approach for investigating whether two of the foam properties, i.e. density and elastic modulus, influenced recorded anteroposterior and lateral torque variance with eyes open and eyes closed. Thirty healthy adults (mean age 22.5 years) were assessed with posturography using three different types of foam block placed on a force platform. These blocks were categorised: firm foam, medium foam and soft foam by their elastic modulus. To investigate the spectral characteristics of recorded body movements, variance values were calculated for total movements, movements <0.1Hz and movements >0.1Hz. Results showed that anteroposterior and lateral torque variances >0.1Hz were larger when standing on the firm foam compared with medium and soft foam and in turn were larger on the medium foam compared with the soft foam with eyes closed. Moreover, GLM and correlation analysis demonstrated that the properties of the foam blocks affected anteroposterior torque variance >0.1Hz and lateral torque variance in all frequency ranges. In addition, the stabilising effect of vision in the anteroposterior direction had a greater influence when the subjects' stability was increasingly challenged by the support surface, as illustrated by the higher torque variance values. In conclusion, caution should be taken when analysing balance deficits with foam test setups, because the foam properties may influence the recorded body movements.

  18. Postural responses to various frequencies of vibration of the triceps surae and forefoot sole during quiet standing.

    PubMed

    Naka, Masami; Fujiwara, Katsuo; Kiyota, Naoe

    2015-01-01

    The purpose of this study was to determine the role of somatosensory input to the sensory reference system in quiet standing. We applied vibration (0.5 mm amplitude, 1-60 Hz) to the triceps surae and the forefoot sole to stimulate the muscle spindles and the mechanoreceptors, respectively, and evaluated postural responses. Thirteen young healthy adults who showed backward-lean and forward-lean responses to vibration at high and low frequencies, respectively, participated in the full experiment. The lowest vibration frequencies inducing backward-lean responses (B-LF) were 15-55 Hz for the triceps surae and 16-60 Hz for the forefoot sole. The highest frequencies inducing forward-lean responses (F-HF) were 3-18 Hz for the triceps surae and 1-20 Hz for the forefoot sole. When vibration was simultaneously applied to the triceps surae and forefoot sole at F-HF, no response was induced in 70% of trials. A forward-lean response was induced in the remaining 30% of trials. Simultaneous vibration of the triceps surae and forefoot sole at B-LF induced backward-lean responses in all trials. All postural responses occurred 0.5-4.3 s after vibration onset. Postural responses to high-frequency vibration conceivably occur as a compensatory movement to the illusionary perception that standing position is deviating forward from quiet standing, which must be a reference position. Postural responses to low-frequency vibration possibly occur to equalize the positional information that is received from the triceps surae and the forefoot sole. Both postural responses are likely to involve the sensory reference system, which is located in the supraspinal nervous system.

  19. Temporal Structure of Support Surface Translations Drive the Temporal Structure of Postural Control During Standing

    PubMed Central

    Rand, Troy J.; Myers, Sara A.; Kyvelidou, Anastasia; Mukherjee, Mukul

    2015-01-01

    A healthy biological system is characterized by a temporal structure that exhibits fractal properties and is highly complex. Unhealthy systems demonstrate lowered complexity and either greater or less predictability in the temporal structure of a time series. The purpose of this research was to determine if support surface translations with different temporal structures would affect the temporal structure of the center of pressure (COP) signal. Eight healthy young participants stood on a force platform that was translated in the anteroposterior direction for input conditions of varying complexity: white noise, pink noise, brown noise, and sine wave. Detrended fluctuation analysis was used to characterize the long-range correlations of the COP time series in the AP direction. Repeated measures ANOVA revealed differences among conditions (P < .001). The less complex support surface translations resulted in a less complex COP compared to normal standing. A quadratic trend analysis demonstrated an inverted-u shape across an increasing order of predictability of the conditions (P < .001). The ability to influence the complexity of postural control through support surface translations can have important implications for rehabilitation. PMID:25994281

  20. Functionality level and its relation to postural control during sitting-to-stand movement in children with cerebral palsy.

    PubMed

    Pavão, Silvia Leticia; Dos Santos, Adriana Neves; de Oliveira, Ana Beatriz; Rocha, Nelci Adriana Cicuto Ferreira

    2014-02-01

    In this study we studied functional performance and functional balance in children with cerebral palsy (CP) and typically developing (TD) children. The relationship between these components and postural control during sit-to-stand movement (STS) was also investigated. Ten children with CP (GMFCS I and II) and 27 TD children, ages 5-12 years, were included in the study. The Pediatric Evaluation of Disability Inventory (PEDI) and the Pediatric Balance Scale (PBS) were used to measure functional performance and functional balance, respectively. Postural control during STS was assessed by means of a force plate. Participants were asked to stand from a chair with feet over a force plate. Children with CP exhibited lower scores than TD children in the PBS and in the mobility Functional Skills and Caregiver Assistance domains of the PEDI (p≤0.05). In both groups postural control during STS movement was correlated with mobility Caregiver Assistance scores of the PEDI. The results demonstrate that although the participants had mild to moderate motor impairment, they exhibit deficits in their level of functional performance and functional balance compared to typical children. Moreover, it was observed that impairments in postural control during the STS movement are related to functional performance in both groups. This result demonstrates the importance of the structure and function components to the level of activity in children.

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

    PubMed

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

    2009-02-01

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

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

    PubMed

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

    2015-01-01

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

  3. Influence of dual-task on sit-to-stand-to-sit postural control in Parkinson's disease.

    PubMed

    Fernandes, Ângela; Sousa, Andreia S P; Couras, Joana; Rocha, Nuno; Tavares, João Manuel R S

    2015-11-01

    Postural control deficits are the most disabling aspects of Parkinson's disease (PD), resulting in decreased mobility and functional independence. The aim of this study was to assess the postural control stability, revealed by variables based on the centre of pressure (CoP), in individuals with PD while performing a sit-to-stand-to-sit sequence under single- and dual-task conditions. An observational, analytical and cross-sectional study was performed. The sample consisted of 9 individuals with PD and 9 healthy controls. A force platform was used to measure the CoP displacement and velocity during the sit-to-stand-to-sit sequence. The results were statistically analysed. Individuals with PD required greater durations for the sit-to-stand-to-sit sequence than the controls (p < 0.05). The anteroposterior and mediolateral CoP displacement were higher in the individuals with PD (p < 0.05). However, only the anteroposterior CoP velocity in the stand-to-sit phase (p = 0.006) was lower in the same individuals. Comparing the single- and dual-task conditions in both groups, the duration, the anteroposterior CoP displacement and velocity were higher in the dual-task condition (p < 0.05). The individuals with PD presented reduced postural control stability during the sit-to-stand-to-sit sequence, especially when under the dual-task condition. These individuals have deficits not only in motor performance, but also in cognitive performance when performing the sit-to-stand-to-sit sequence in their daily life tasks. Moreover, both deficits tend to be intensified when two tasks are performed simultaneously.

  4. Reproducibility of Standing Posture for X-Ray Radiography: A Feasibility Study of the BalancAid with Healthy Young Subjects

    PubMed Central

    Dewi, Dyah Ekashanti Octorina; Veldhuizen, Albert G.; Burgerhof, Johannes G. M.; Purnama, I Ketut Eddy; van Ooijen, Peter M. A.; Wilkinson, Michael H. F.; Mengko, Tati Latifah Erawati Rajab

    2010-01-01

    Unreliable spinal X-ray radiography measurement due to standing postural variability can be minimized by using positional supports. In this study, we introduce a balancing device, named BalancAid, to position the patients in a reproducible position during spinal X-ray radiography. This study aimed to investigate the performance of healthy young subjects’ standing posture on the BalancAid compared to standing on the ground mimicking the standard X-rays posture in producing a reproducible posture for the spinal X-ray radiography. A study on the posture reproducibility measurement was performed by taking photographs of 20 healthy young subjects with good balance control standing on the BalancAid and the ground repeatedly within two consecutive days. We analyzed nine posterior–anterior (PA) and three lateral (LA) angles between lines through body marks placed in the positions of T3, T7, T12, L4 of the spine to confirm any translocations and movements between the first and second day measurements. No body marks repositioning was performed to avoid any error. Lin’s CCC test on all angles comparing both standing postures demonstrated that seven out of nine angles in PA view, and two out of three angles in LA view gave better reproducibility for standing on the BalancAid compared to standing on the ground. The PA angles concordance is on average better than that of the LA angles. PMID:20473569

  5. Reproducibility of standing posture for X-ray radiography: a feasibility study of the BalancAid with healthy young subjects.

    PubMed

    Dewi, Dyah Ekashanti Octorina; Veldhuizen, Albert G; Burgerhof, Johannes G M; Purnama, I Ketut Eddy; van Ooijen, Peter M A; Wilkinson, Michael H F; Mengko, Tati Latifah Erawati Rajab; Verkerke, Gijsbertus Jacob

    2010-10-01

    Unreliable spinal X-ray radiography measurement due to standing postural variability can be minimized by using positional supports. In this study, we introduce a balancing device, named BalancAid, to position the patients in a reproducible position during spinal X-ray radiography. This study aimed to investigate the performance of healthy young subjects' standing posture on the BalancAid compared to standing on the ground mimicking the standard X-rays posture in producing a reproducible posture for the spinal X-ray radiography. A study on the posture reproducibility measurement was performed by taking photographs of 20 healthy young subjects with good balance control standing on the BalancAid and the ground repeatedly within two consecutive days. We analyzed nine posterior-anterior (PA) and three lateral (LA) angles between lines through body marks placed in the positions of T3, T7, T12, L4 of the spine to confirm any translocations and movements between the first and second day measurements. No body marks repositioning was performed to avoid any error. Lin's CCC test on all angles comparing both standing postures demonstrated that seven out of nine angles in PA view, and two out of three angles in LA view gave better reproducibility for standing on the BalancAid compared to standing on the ground. The PA angles concordance is on average better than that of the LA angles.

  6. Center of Mass Acceleration Feedback Control of Functional Neuromuscular Stimulation for Standing in the Presence of Internal Postural Perturbations

    PubMed Central

    Audu, Musa L.; Triolo, Ronald J.

    2013-01-01

    This study determined the feasibility and performance of center of mass (COM) acceleration feedback control of a neuroprosthesis utilizing functional neuromuscular stimulation (FNS) to restore standing balance to a single subject paralyzed by a motor and sensory complete, thoracic-level spinal cord injury (SCI). An artificial neural network (ANN) was created to map gain-modulated changes in total body COM acceleration estimated from body-mounted sensors to optimal changes in stimulation required to maintain standing. Feedback gains were systematically tuned to minimize the upper extremity (UE) loads applied by the subject to an instrumented support device during internally generated postural perturbations produced by volitional reaching and object manipulation. Total body COM acceleration was accurately estimated (> 90% variance explained) from two three-dimensional (3-D) accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, COM acceleration feedback control of stimulation improved standing performance by reducing the UE loading required to resist internal postural disturbances by 27%. This case study suggests that COM acceleration feedback could potentially be advantageous in a standing neuroprosthesis since it can be implemented with only a few feedback parameters and requires minimal instrumentation for comprehensive, 3-D control of dynamic standing function. PMID:23299260

  7. Sitting and standing postures are corrected by adjustable furniture with lowered muscle tension in high-school students.

    PubMed

    Koskelo, R; Vuorikari, K; Hänninen, O

    2007-10-01

    This study compared the effect of 24 months of adjustable school desks and chairs usage (the intervention) and traditional non-adjustable usage (the control condition) on sitting and standing postures, muscle strength, classroom muscle tension, pain and learning in 15 (8 female and 7 male) high-school students and 15 anthropometrically and gender matched control students from neighbouring schools. It was assessed whether any responses took place after growth cessation. In comparison with controls, the intervention group of students' sitting postures standing kyphosis, scoliosis and lordosis became significantly better, both before and after growth cessation. Trunk muscle strength increased in the intervention students whose muscle tension during classes fell significantly in the trapezius and lumbar muscles, whereas in control students' lumbar tension increased. Headache and low-back pain correlated with neck-shoulder pain and trapezius muscle tension. Intervention students reported that they experienced benefits from the adjustable tables and chairs. They also received significantly better overall marks than the controls at the end of high school. It is concluded that the adjustable school desks and chairs promoted better sitting and standing postures, increased muscle strength, alleviated pain and appeared to be associated with better overall academic marks.

  8. Influence of Cervical Spine Mobility on the Focal and Postural Components of the Sit-to-Stand Task.

    PubMed

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

    The aim of this study was to determine the influence of cervical spine mobility on the focal and postural components of the sit-to-stand transition, which represent the preparatory and execution phases of the task, respectively. Sixteen asymptomatic female participants (22 ± 3 years, 163 ± 0,06 cm, 57,5 ± 5 kg), free of any neurological or musculoskeletal disorders, performed six trials of the sit-to-stand task at maximum speed, in four experimental conditions varying the mobility of the cervical spine by means of three different splints. A six-channel force plate, which collected the reaction forces and moments applied at its top surface, was used to calculate the center of pressure displacements along the anterior-posterior and medial-lateral axes. The local accelerations of the head, spine, and pelvis, were assessed by three pairs of accelerometers, oriented along the vertical and anterior-posterior axes. Restriction of cervical spine mobility resulted in an increased duration of the focal movement, associated with longer and larger postural adjustments. These results suggest that restricted cervical spine mobility impairs the posturo-kinetic capacity during the sit-to-stand task, leading to a lower motor performance and a reorganization of the anticipatory postural adjustments. In a clinical context, it might be assumed that preserving the articular free play of the cervical spine might be useful to favor STS performance and autonomy.

  9. Influence of Cervical Spine Mobility on the Focal and Postural Components of the Sit-to-Stand Task

    PubMed Central

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

    The aim of this study was to determine the influence of cervical spine mobility on the focal and postural components of the sit-to-stand transition, which represent the preparatory and execution phases of the task, respectively. Sixteen asymptomatic female participants (22 ± 3 years, 163 ± 0,06 cm, 57,5 ± 5 kg), free of any neurological or musculoskeletal disorders, performed six trials of the sit-to-stand task at maximum speed, in four experimental conditions varying the mobility of the cervical spine by means of three different splints. A six-channel force plate, which collected the reaction forces and moments applied at its top surface, was used to calculate the center of pressure displacements along the anterior-posterior and medial-lateral axes. The local accelerations of the head, spine, and pelvis, were assessed by three pairs of accelerometers, oriented along the vertical and anterior-posterior axes. Restriction of cervical spine mobility resulted in an increased duration of the focal movement, associated with longer and larger postural adjustments. These results suggest that restricted cervical spine mobility impairs the posturo-kinetic capacity during the sit-to-stand task, leading to a lower motor performance and a reorganization of the anticipatory postural adjustments. In a clinical context, it might be assumed that preserving the articular free play of the cervical spine might be useful to favor STS performance and autonomy. PMID:28400724

  10. Postural Stability Characteristics of Transtibial Amputees Wearing Different Prosthetic Foot Types When Standing on Various Support Surfaces

    PubMed Central

    Arifin, Nooranida; Abu Osman, Noor Azuan; Ali, Sadeeq; Wan Abas, Wan Abu Bakar

    2014-01-01

    Purpose. This study aimed to evaluate the effects of prosthetic foot types on the postural stability among transtibial amputees when standing on different support surfaces. Materials and Methods. The postural stability of 10 transtibial amputees wearing solid ankle cushion heel (SACH) foot, single-axis (SA) foot, and energy-saving and return (ESAR) foot was assessed. Results were compared with able-bodied participants. Anterior-posterior stability index (APSI), mediolateral stability index (MLSI), and overall stability index (OSI) were measured by computed posturography in an upright stance on firm, foam, and unstable support surfaces. Results. The mean OSI score of SACH foot was significantly lower than that of an ESAR foot when the participants were standing on a compliant surface. When compared to able-bodied group, MLSI score was significantly higher for each of the prosthetic foot groups while OSI score was significantly higher for ESAR foot only in foam condition. Conclusions. Differences between prosthetic foot types and groups (amputees versus able-bodied) can only be distinguished when individuals were standing on a compliant surface. Amputees exhibited an increased postural instability in the mediolateral direction than able-bodied individuals. Hence, the restoration of stability in the frontal plane and the enhancement of proprioception at the residual limb should be the basis of rehabilitation programs. PMID:25003155

  11. Postural stability characteristics of transtibial amputees wearing different prosthetic foot types when standing on various support surfaces.

    PubMed

    Arifin, Nooranida; Abu Osman, Noor Azuan; Ali, Sadeeq; Gholizadeh, Hossein; Abas, Wan Abu Bakar Wan

    2014-01-01

    This study aimed to evaluate the effects of prosthetic foot types on the postural stability among transtibial amputees when standing on different support surfaces. The postural stability of 10 transtibial amputees wearing solid ankle cushion heel (SACH) foot, single-axis (SA) foot, and energy-saving and return (ESAR) foot was assessed. Results were compared with able-bodied participants. Anterior-posterior stability index (APSI), mediolateral stability index (MLSI), and overall stability index (OSI) were measured by computed posturography in an upright stance on firm, foam, and unstable support surfaces. The mean OSI score of SACH foot was significantly lower than that of an ESAR foot when the participants were standing on a compliant surface. When compared to able-bodied group, MLSI score was significantly higher for each of the prosthetic foot groups while OSI score was significantly higher for ESAR foot only in foam condition. Differences between prosthetic foot types and groups (amputees versus able-bodied) can only be distinguished when individuals were standing on a compliant surface. Amputees exhibited an increased postural instability in the mediolateral direction than able-bodied individuals. Hence, the restoration of stability in the frontal plane and the enhancement of proprioception at the residual limb should be the basis of rehabilitation programs.

  12. Dynamic Response of the Standing Human Body Exposed to Vertical Vibration: Influence of Posture and Vibration Magnitude

    NASA Astrophysics Data System (ADS)

    Matsumoto, Y.; Griffin, M. J.

    1998-04-01

    The influence of the posture of the legs and the vibration magnitude on the dynamic response of the standing human body exposed to vertical whole-body vibration has been investigated. Motions were measured on the body surface at the first and eighth thoracic and fourth lumbar vertebrae (T1, T8 and L4), at the right and left iliac crests and at the knee. Twelve subjects took part in the experiment with three leg postures (normal, legs bent and one leg), and five magnitudes of random vibration (0·125-2·0 ms-2r.m.s.) in the frequency range from 0[msde]5-30 Hz. The main resonance frequencies of the apparent masses at 1·0 ms-2r.m.s. differed between postures: 5·5 Hz in the normal posture, 2·75 Hz in the legs bent posture and 3·75 Hz in the one leg posture. In the normal posture, the transmissibilities to L4 and the iliac crests showed a similar trend to the apparent mass at low frequencies. With the legs straight, no resonance was observed in the legs at frequencies below 15 Hz. In the legs bent posture, a bending motion of the legs at the knee and a pitching or bending motion of the upper-body appeared to contribute to the resonance of the whole body as observed in the apparent mass, with attenuation of vibration transmission to the upper body at high frequencies. In the one leg posture, coupled rotational motion of the whole upper-body about the hip joint may have contributed to the resonance observed in the apparent mass at low frequencies and the attenuation of vertical vibration transmission at high frequencies. The resonance frequency of the apparent mass in the normal posture decreased from 6·75-5·25 Hz with increasing vibration magnitude from 0·125 to 2·0 ms-2r.m.s. This “softening” effect was also found in the transmissibilities to many parts of the body that showed resonances.

  13. Neck Posture Clusters and Their Association With Biopsychosocial Factors and Neck Pain in Australian Adolescents.

    PubMed

    Richards, Karen V; Beales, Darren J; Smith, Anne J; O'Sullivan, Peter B; Straker, Leon M

    2016-10-01

    There is conflicting evidence on the association between sagittal neck posture and neck pain. The purposes of this study were: (1) to determine the existence of clusters of neck posture in a cohort of 17-year-olds and (2) to establish whether identified subgroups were associated with biopsychosocial factors and neck pain. This was a cross-sectional study. The adolescents (N=1,108) underwent 2-dimensional photographic postural assessment in a sitting position. One distance and 4 angular measurements of the head, neck, and thorax were calculated from photo-reflective markers placed on bony landmarks. Subgroups of sagittal sitting neck posture were determined by cluster analysis. Height and weight were measured, and lifestyle and psychological factors, neck pain, and headache were assessed by questionnaire. The associations among posture subgroups, neck pain, and other factors were evaluated using logistic regression. Four distinct clusters of sitting neck posture were identified: upright, intermediate, slumped thorax/forward head, and erect thorax/forward head. Significant associations between cluster and sex, weight, and height were found. Participants classified as having slumped thorax/forward head posture were at higher odds of mild, moderate, or severe depression. Participants classified as having upright posture exercised more frequently. There was no significant difference in the odds of neck pain or headache across the clusters. The results are specific to 17-year-olds and may not be applicable to adults. Meaningful sagittal sitting neck posture clusters were identified in 17-year-olds who demonstrated some differences with biopsychosocial profiling. The finding of no association between cluster membership and neck pain and headaches challenges widely held beliefs about the role of posture in adolescent neck pain. © 2016 American Physical Therapy Association.

  14. High flow variant postural orthostatic tachycardia syndrome amplifies the cardiac output response to exercise in adolescents.

    PubMed

    Pianosi, Paolo T; Goodloe, Adele H; Soma, David; Parker, Ken O; Brands, Chad K; Fischer, Philip R

    2014-08-01

    Postural orthostatic tachycardia syndrome (POTS) is characterized by chronic fatigue and dizziness and affected individuals by definition have orthostatic intolerance and tachycardia. There is considerable overlap of symptoms in patients with POTS and chronic fatigue syndrome (CFS), prompting speculation that POTS is akin to a deconditioned state. We previously showed that adolescents with postural orthostatic tachycardia syndrome (POTS) have excessive heart rate (HR) during, and slower HR recovery after, exercise - hallmarks of deconditioning. We also noted exaggerated cardiac output during exercise which led us to hypothesize that tachycardia could be a manifestation of a high output state rather than a consequence of deconditioning. We audited records of adolescents presenting with long-standing history of any mix of fatigue, dizziness, nausea, who underwent both head-up tilt table test and maximal exercise testing with measurement of cardiac output at rest plus 2-3 levels of exercise, and determined the cardiac output () versus oxygen uptake () relationship. Subjects with chronic fatigue were diagnosed with POTS if their HR rose ≥40 beat·min(-1) with head-up tilt. Among 107 POTS patients the distribution of slopes for the , relationship was skewed toward higher slopes but showed two peaks with a split at ~7.0 L·min(-1) per L·min(-1), designated as normal (5.08 ± 1.17, N = 66) and hyperkinetic (8.99 ± 1.31, N = 41) subgroups. In contrast, cardiac output rose appropriately with in 141 patients with chronic fatigue but without POTS, exhibiting a normal distribution and an average slope of 6.10 ± 2.09 L·min(-1) per L·min(-1). Mean arterial blood pressure and pulse pressure from rest to exercise rose similarly in both groups. We conclude that 40% of POTS adolescents demonstrate a hyperkinetic circulation during exercise. We attribute this to failure of normal regional vasoconstriction during exercise, such that patients must increase flow through an

  15. Quantitative postural analysis and pain in children and adolescents victims of burns

    PubMed Central

    Valenciano, Paola Janeiro; Itakussu, Edna Yukimi; Trelha, PhD, Celita Salmaso; Fujisawa, PhD, Dirce Shizuko

    2015-01-01

    [Purpose] This study aimed to quantitatively assess postural alignment in both frontal and sagittal planes, as well as pain in children and adolescents victims of burn injuries. [Subjects and Methods] This cross-sectional study included 21 victims of burns, nine children (age [mean ± SD], 7.3 ± 1.1 yrs) and 12 adolescents (12,0 ± 1.4 yrs), classified as medium and large burns, being investigated on pain and postural alignment evaluated by photogrammetry. Pain intensity was assessed by face scales and postural examination included the assessment of global and thoraco-lumbo-pelvic alignment by previously designed protocols. [Results] Only two adolescents reported mild pain associated with burn injuries, whereas deviations of the projection of the gravity center; forward head posture, and scapular asymmetry were observed in both groups. In the analysis of the thoraco-lumbo-pelvic alignment, children tended to have anterior inclination trunk, increased thoracic kyphosis and lumbar lordosis, while in adolescents, increased thoracic kyphosis and lumbar lordosis were observed. [Conclusion] The results indicate that due to the postural alterations and asymmetries in both frontal and sagittal planes, there is an increased risk of developing scoliosis and possible future pain. Thus, physiotherapy is indicated and should be maintained until complete growth is reached. PMID:26834321

  16. Posture Alignment of Adolescent Idiopathic Scoliosis: Photogrammetry in Scoliosis School Screening.

    PubMed

    Penha, Patrícia Jundi; Penha, Nárima Lívia Jundi; De Carvalho, Bárbarah Kelly Gonçalves; Andrade, Rodrigo Mantelatto; Schmitt, Ana Carolina Basso; João, Sílvia Maria Amado

    The objective of this study was to describe the posture patterns of adolescents diagnosed with adolescent idiopathic scoliosis (AIS) in a scoliosis school screening (SSS). Two-dimensional photogrammetry was used to assess the posture of 37 adolescents diagnosed with scoliosis (scoliosis group, SG) (Cobb angle ≥10°) and 76 adolescents with a false positive diagnosis (false positive group, FPG) (Cobb angle <10°, angle of trunk rotation ≥7°). In total, 2562 10- to 14-year-old adolescents were enrolled in the SSS, which was performed in public schools in the cities of Amparo, Pedreira, and Mogi Mirim in the state of São Paulo, Brazil. Their posture was analyzed using Postural Analysis Software. Continuous variables were tested using Student t test, and categorical variables were tested using a χ2 test. The SG, FPG, simple curve group, and double curve group were all compared. Bivariate analysis was used to identify associations between postural deviations and scoliosis. The adopted significance level was α = .05. The SG (2.7 ± 1.9°) had greater shoulder obliquity than the FPG (1.9 ± 1.4°) (P = .010), and this deviation was associated with scoliosis (odds ratio [95% CI] P = 1.4 [1.1-1.8] 0.011). The SG had asymmetry between the right- and left-side lower limb frontal angle, shoulder sagittal alignment, and knee angle. The double curve group (3 ± 1.7°) presented a greater value of the vertical alignment of the torso than the simple curve group did (1.9 ± 1°; P = .032). Adolescents diagnosed with AIS in an SSS had greater shoulder obliquity and asymmetry between the right and left sides. Shoulder obliquity was the only postural deviation associated with AIS. Copyright © 2017. Published by Elsevier Inc.

  17. Vestibulo-spinal and vestibulo-ocular reflexes are modulated when standing with increased postural threat.

    PubMed

    Naranjo, E N; Cleworth, T W; Allum, J H J; Inglis, J T; Lea, J; Westerberg, B D; Carpenter, M G

    2016-02-01

    We investigated how vestibulo-spinal reflexes (VSRs) and vestibulo-ocular reflexes (VORs) measured through vestibular evoked myogenic potentials (VEMPs) and video head impulse test (vHIT) outcomes, respectively, are modulated during standing under conditions of increased postural threat. Twenty-five healthy young adults stood quietly at low (0.8 m from the ground) and high (3.2 m) surface height conditions in two experiments. For the first experiment (n = 25) VEMPs were recorded with surface EMG from inferior oblique (IO), sternocleidomastoid (SCM), trapezius (TRP), and soleus (SOL) muscles in response to 256 air-conducted short tone bursts (125 dB SPL, 500 Hz, 4 ms) delivered via headphones. A subset of subjects (n = 19) also received horizontal and vertical head thrusts (∼150°/s) at each height in a separate session, comparing eye and head velocities by using a vHIT system for calculating the functional VOR gains. VEMP amplitudes (IO, TRP, SOL) and horizontal and vertical vHIT gains all increased with high surface height conditions (P < 0.05). Changes in IO and SCM VEMP amplitudes as well as horizontal vHIT gains were correlated with changes in electrodermal activity (ρ = 0.44-0.59, P < 0.05). VEMP amplitude for the IO also positively correlated with fear (ρ = 0.43, P = 0.03). Threat-induced anxiety, fear, and arousal have significant effects on VSR and VOR gains that can be observed in both physiological and functional outcome measures. These findings provide support for a potential central modulation of the vestibular nucleus complex through excitatory inputs from neural centers involved in processing fear, anxiety, arousal, and vigilance.

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

    PubMed

    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 (p<0.001, CI: 1.73, 5.31) than for ACLPT (p=0.006, CI: 0.56, 4.12) relative to CTRL. Duration of SD-peaks was smaller for both ACLR and ACLPT (p<0.001, CI: -4.04, -1.23 and -3.82, -1.03, respectively) compared to CTRL. CoM-area in the ACL-groups did not differ from CTRL. ACL-injured subjects demonstrated greater postural 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.

  19. External landmark, body surface, and volume data of a mid-sized male in seated and standing postures.

    PubMed

    Gayzik, F S; Moreno, D P; Danelson, K A; McNally, C; Klinich, K D; Stitzel, Joel D

    2012-09-01

    The purpose of this study was to acquire external landmark, undeformed surface, and volume data from a pre-screened individual representing a mid-sized male (height 174.9 cm, weight 78.6 ± 0.77 kg) in the seated and standing postures. The individual matched the 50th percentile value of 15 measures of external anthropometry from previous anthropometric studies with an average deviation of 3%. As part of a related study, a comprehensive full body medical image data set was acquired from the same individual on whom landmark data were collected. Three dimensional bone renderings from this data were used to visually verify the landmark and surface results. A total of 54 landmarks and external surface data were collected using a 7-axis digitizer. A seat buck designed in-house with removable back and seat pan panels enabled collection of undeformed surface contours of the back, buttocks, and posterior thigh. Eight metrics describing the buck positioning are provided. A repeatability study was conducted with three trials to assess intra-observer variability. Total volume and surface area of the seated model were found to be 75.8 × 10(3) cm(3) and 18.6 × 10(3) cm(2) and match the volume and surface area of the standing posture within 1%. Root mean squared error values from the repeatability study were on average 5.9 and 6.6 mm for the seated and standing postures respectively. The peak RMS error as a percentage of the centroid size of the landmark data sets were 3% for both the seated and standing trials. The data were collected as part of a global program on the development of an advanced human body model for blunt injury simulation. In addition, the reported data can be used for many diverse applications of biomechanical research such as ergonomics and morphometrics studies.

  20. Measurement of three-dimensional posture and trajectory of lower body during standing long jumping utilizing body-mounted sensors.

    PubMed

    Ibata, Yuki; Kitamura, Seiji; Motoi, Kosuke; Sagawa, Koichi

    2013-01-01

    The measurement method of three-dimensional posture and flying trajectory of lower body during jumping motion using body-mounted wireless inertial measurement units (WIMU) is introduced. The WIMU is composed of three-dimensional (3D) accelerometer and gyroscope of two kinds with different dynamic range and one 3D geomagnetic sensor to adapt to quick movement. Three WIMUs are mounted under the chest, right thigh and right shank. Thin film pressure sensors are connected to the shank WIMU and are installed under right heel and tiptoe to distinguish the state of the body motion between grounding and jumping. Initial and final postures of trunk, thigh and shank at standing-still are obtained using gravitational acceleration and geomagnetism. The posture of body is determined using the 3D direction of each segment updated by the numerical integration of angular velocity. Flying motion is detected from pressure sensors and 3D flying trajectory is derived by the double integration of trunk acceleration applying the 3D velocity of trunk at takeoff. Standing long jump experiments are performed and experimental results show that the joint angle and flying trajectory agree with the actual motion measured by the optical motion capture system.

  1. The influence of age, anxiety and concern about falling on postural sway when standing at an elevated level.

    PubMed

    Sturnieks, Daina L; Delbaere, Kim; Brodie, Matthew A; Lord, Stephen R

    2016-10-01

    Psychological processes may influence balance and contribute to the risk of falls in older people. While a self-reported fear of falling is associated with increased postural sway, inducing fear using an elevated platform can lead to reduced sway, suggesting different underlying mechanisms whereby fear may influence balance control. This study examined changes in postural sway, muscle activity and physiological measures of arousal while standing on a 65cm elevated platform, compared to floor level, in young and older adults. The older adults were classified as fall concerned or not fall concerned based on the Falls Efficacy Scale-International and anxious or not anxious based on the Goldberg Anxiety Scale. Fall concern did not affect the physiological and sway response to the elevated platform. In response to the postural threat, the anxious participants increased their sway frequency (p=0.001) but did not reduce sway range (p=0.674). Conversely, non-anxious participants showed an adaptive tightening of balance control, effectively reducing sway range in the elevated condition (p<0.001). Generalised anxiety in older adults appears to differentially affect postural control strategies under threatening conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Spino-pelvic postural changes between the standing and sitting human position: proposal of a method for its systematic analysis.

    PubMed

    Berthonnaud, E; Hilmi, R; Labelle, H; Dimnet, J

    2011-09-01

    This study presents numerical tools, based on biplanar radiography, allowing to analyze the 3D changes in position and length of the various spinal segments with respect to the pelvis which occur between the standing and sitting positions. Three asymptomatic adult subjects and twelve adult patients with low back pain or scoliosis had biplanar calibrated radiographs in the erect posture and sitting position. The 3D points of the spinal curve were then reconstructed from their plane projections using a standard photogrammetric technique. A technical data form has been formulated to present and summarize the complex 3D spino-pelvic changes occurring between both postures. The spine and pelvis are displayed as a chain of linear articulated segments, in their plane of maximum curvature, allowing users to compare both postures and to assess the global and local spinal mobility between the two fixed postures. Examples of asymptomatic volunteers and of subjects with low back pain or scoliosis demonstrate that different strategies can be adopted to perform this simple task and are presented to illustrate these new techniques and their clinical potential to discriminate between and within normal and pathological conditions.

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

    NASA Astrophysics Data System (ADS)

    Qianxiang, Zhou; Chao, Ma; Xiaohui, Zheng

    sEMG analysis of astronaut upper arm during isotonic muscle actions with normal standing posture*1 Introduction Now the research on the isotonic muscle actions by using Surface Electromyography (sEMG) is becoming a pop topic in fields of astronaut life support training and rehabilitations. And researchers paid more attention on the sEMG signal processes for reducing the influence of noise which is produced during monitoring process and the fatigue estimation of isotonic muscle actions with different force levels by using the parameters which are obtained from sEMG signals such as Condition Velocity(CV), Median Frequency(MDF), Mean Frequency(MNF) and so on. As the lucubrated research is done, more and more research on muscle fatigue issue of isotonic muscle actions are carried out with sEMG analysis and subjective estimate system of Borg scales at the same time. In this paper, the relationship between the variable for fatigue based on sEMG and the Borg scale during the course of isotonic muscle actions of the upper arm with different contraction levels are going to be investigated. Methods 13 young male subjects(23.4±2.45years, 64.7±5.43Kg, 171.7±5.41cm) with normal standing postures were introduced to do isotonic actions of the upper arm with different force levels(10% MVC, 30%MVC and 50%MVC). And the MVC which means maximal voluntary contraction was obtained firstly in the experiment. Also the sEMG would be recorded during the experiments; the Borg scales would be recorded for each contraction level. By using one-third band octave method, the fatigue variable (p) based on sEMG were set up and it was expressed as p = i g(fi ) · F (fi ). And g(fi ) is defined as the frequent factor which was 0.42+0.5 cos(π fi /f0 )+0.08 cos(2π fi /f0 ), 0 < FI fi 0, orf0 ≤> f0 . According to the equations, the p could be computed and the relationship between variable p and the Borg scale would be investigated. Results In the research, three kinds of fitted curves between

  4. Hemispheric specificity for proprioception: Postural control of standing following right or left hemisphere damage during ankle tendon vibration.

    PubMed

    Duclos, Noémie C; Maynard, Luc; Abbas, Djawad; Mesure, Serge

    2015-11-02

    Right brain damage (RBD) following stroke often causes significant postural instability. In standing (without vision), patients with RBD are more unstable than those with left brain damage (LBD). We hypothesised that this postural instability would relate to the cortical integration of proprioceptive afferents. The aim of this study was to use tendon vibration to investigate whether these changes were specific to the paretic or non-paretic limbs. 14 LBD, 12 RBD patients and 20 healthy subjects were included. Displacement of the Centre of Pressure (CoP) was recorded during quiet standing, then during 3 vibration conditions (80 Hz - 20s): paretic limb, non-paretic limb (left and right limbs for control subjects) and bilateral. Vibration was applied separately to the peroneal and Achilles tendons. Mean antero-posterior position of the CoP, variability and velocity were calculated before (4s), during and after (24s) vibration. For all parameters, the strongest perturbation was during Achilles vibrations. The Achilles non-paretic condition induced a larger backward displacement than the Achilles paretic condition. This condition caused specific behaviour on the velocity: the LBD group was perturbed at the onset of the vibrations, but gradually recovered their stability; the RBD group was significantly perturbed thereafter. After bilateral Achilles vibration, RBD patients required the most time to restore initial posture. The reduction in use of information from the paretic limb may be a central strategy to deal with risk-of-fall situations such as during Achilles vibration. The postural behaviour is profoundly altered by lesions of the right hemisphere when proprioception is perturbed.

  5. Walking-induced muscle fatigue impairs postural control in adolescents with unilateral spastic cerebral palsy.

    PubMed

    Vitiello, Damien; Pochon, Ludmilla; Malatesta, Davide; Girard, Olivier; Newman, Christopher J; Degache, Francis

    2016-01-01

    Fatigue is likely to be an important limiting factor in adolescents with spastic cerebral palsy (CP). To determine the effects of walking-induced fatigue on postural control adjustments in adolescents with unilateral CP and their typically developing (TD) peers. Ten adolescents with CP (14.2 ± 1.7 yr) and 10 age-, weight- and height-matched TD adolescents (14.1 ± 1.9 yr) walked for 15 min on a treadmill at their preferred walking speed. Before and after this task, voluntary strength capacity of knee extensors (MVC) and postural control were evaluated in 3 conditions: eyes open (EO), eyes closed (EC) and with dual cognitive task (EODT). After walking, MVC decreased significantly in CP (-11%, P<0.05) but not in TD. The CoP area was only significantly increased in CP (90%, 34% and 60% for EO, EC and EODT conditions, respectively). The CoP length was significantly increased in the EO condition in CP and TD (20% and 21%) and was significantly increased in the EODT condition by 18% in CP only. Unlike TD adolescents, treadmill walking for 15 min at their preferred speed lead to significant knee extensor strength losses and impairments in postural control in adolescents with unilateral spastic CP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The effects of foot position and orientation on inter- and intra-foot coordination in standing postures: a frequency domain PCA analysis.

    PubMed

    Wang, Zheng; Molenaar, Peter C M; Molenaar, Peter M C; Newell, Karl M

    2013-09-01

    We investigated the effect of foot position and foot orientation on asymmetrical body weight loading and the inter- and intra-foot coordination dynamics of standing postures. The participants were instructed to stand with the feet side-by-side and in staggered and tandem positions with the right foot oriented at different angles (30, 60 and 90°). The results showed that the participants naturally loaded more on their left foot when positioned with their right foot forward. As the orientation of the right foot was changed from 90 to 30°, they loaded a significantly large proportion of their body weight on their left foot and the degree of coordination of the 4 COP time series increased. Foot position, constrains both the area of the base of support and the loading of the feet, played an important role differentiating the contribution of each COP to the postural control system. In particular, when postural stance was challenged by the limitation of the base of support, the COPs in the unstable plane (inter-foot coordination) showed larger factor weightings. In contrast, when standing posture was not challenged by the base of support boundary, the COPs of the more loaded foot (intra-foot coordination) dominated foot coordination in postural control. These findings show that the mechanical constraints of foot position and orientation interact to channel different patterns of inter- and intra-foot coordination dynamics of standing postures.

  7. Is there an association between variables of postural control and strength in adolescents?

    PubMed

    Granacher, Urs; Gollhofer, Albert

    2011-06-01

    Is there an association between variables of postural control and strength in adolescents? The risk of sustaining sport injuries is particularly high in adolescents. Deficits in postural control and muscle strength represent 2 important intrinsic injury risk factors. Therefore, the purpose of this study was to investigate the relationship between variables of static and dynamic postural control and isometric and dynamic muscle strength and to find out whether there is an association between measures of postural control and muscle strength. Twenty-eight adolescents participated in this study (age 16.8 ± 0.6 years; body mass index 20.5 ± 1.8 kg · m(-2)). Biomechanic tests included the measurements of maximal isometric leg extension force (MIF) and rate of force development (RFDmax) of the leg extensors on a leg press with the feet resting on a force platform, vertical jumping force, and height (countermovement jump [CMJ]) on a force plate and the assessment of static (1-legged stance on a balance platform) and dynamic (mediolateral perturbation impulse on a balance platform) postural control. The significance level was set at p < 0.05. No significant associations were observed between measures of static and dynamic postural control. Significant positive correlations were detected between variables of isometric and dynamic muscle strength with r-values ranging from 0.441 to 0.779 (p < 0.05). Based on these models, a 100-N increase in MIF of the leg extensors was associated with 3.9, 4.2, and 6.5% better maximal CMJ force, CMJ height, and RFDmax, respectively. No significant correlations were observed between variables of postural control and muscle strength. The nonsignificant correlation between static/dynamic postural control and muscle strength implies that primarily dynamic measures of postural control should be incorporated in injury risk assessment and that postural control and muscle strength are independent of each other and may have to be trained

  8. Fatigue does not conjointly alter postural and cognitive performance when standing in a shooting position under dual-task conditions.

    PubMed

    Bermejo, José Luis; García-Massó, Xavier; Paillard, Thierry; Noé, Frédéric

    2017-04-03

    This study investigated the effects of fatigue on balance control and cognitive performance in a standing shooting position. Nineteen soldiers were asked to stand while holding a rifle (single task - ST). They also had to perform this postural task while simultaneously completing a cognitive task (dual task - DT). Both the ST and DT were performed in pre- and post-fatigue conditions. In pre-fatigue, participants achieved better balance control in the DT than in the ST, thus suggesting that the increased cognitive activity associated with the DT improves balance control by shifting the attentional focus away from a highly automatised activity. In post-fatigue, balance control was degraded in both the ST and DT, while reaction time was enhanced in the first minutes following the fatiguing exercise without affecting the accuracy of response in the cognitive task, which highlights the relative independent effects of fatigue on balance control and cognitive performance.

  9. Role of the sensorimotor cortex in postural adjustments accompanying a conditioned paw lift in the standing cat.

    PubMed

    Birjukova, E V; Dufossé, M; Frolov, A A; Ioffé, M E; Massion, J

    1989-01-01

    The role of the sensorimotor cortex in the postural adjustments associated with conditioned paw lifting movements was investigated in the cat. Cats were trained to stand quietly on four strain gauge equipped platforms and to perform a lift-off movement with one forelimb when a conditioned tone was presented. The parameters recorded were the vertical forces exerted by the paws on each platform, the lateral and antero-posterior displacements of rods implanted on the T2, T12, L5 vertebrae as well as their rotation, and the EMG of triceps and biceps of both forelimbs. Before lesion, the postural adjustment consisted of a "non-diagonal" pattern where the CG was displaced laterally inside the triangle formed by the three remaining supporting limbs. Here a lateral bending of the thoracic column toward the supporting forelimb could be observed. The associated EMG pattern consisted of an early activation of the triceps lateral head in the moving limb which was probably responsible for the body displacement toward the opposite side, and a late biceps activation associated with the lift. In the supporting forelimb, a coactivation of the biceps and triceps was usually present. After contralateral sensorimotor lesion, the conditioned lifting movements were lost for 4-15 days after the lesion, before being subsequently recovered. The same lateral CG displacement and bending of the back was seen after lesion as before, which indicates that the goal of postural adjustment was preserved. However, the means of reaching it were modified.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Effect of Muscle Vibration on Postural Balance of Parkinson’s Diseases Patients in Bipedal Quiet Standing

    PubMed Central

    Han, Jintae; Jung, Jaemin; Lee, Junghoon; Kim, Eunjung; Lee, Myunghee; Lee, Keunhee

    2013-01-01

    [Purpose] The purpose of this study was to investigate the effect of muscle vibration applied to the lower extremities on static postural balance of patients with Parkinson’s disease (PD). [Subjects] Seven subjects with Parkinson’s disease participated in this study. [Methods] The oscillators of vibration were attached to the muscle bellies of the tibialis anterior, gastrocnemius, biceps femoris, and rectus femoris on both sides of the lower extremities with adhesive tape. A vibration frequency of 60 Hz was used to induce static postural reactions. Subjects’ center of pressure (COP) sway and peak ground reaction force (GRF) were measured with their eyes open with and without vibration. COP sway and peak GRF (Fx, Fy, Fz) were measured using a force plate (AMTI, Newton, USA), which provides x, y and z coordinates of body movement. [Results] The area of COP sway with vibration was significantly smaller than that with no vibration, but the length of COP sway showed no difference between two conditions. Peak medial-lateral maximum force (Fy) with vibration was significantly higher than that with no vibration, but peak anterior-posterior force (Fx) and peak vertical force (Fz) showed no differences. [Conclusion] These results suggest that vibration applied to the lower extremities can help PD patients control postural balance during quiet standing. PMID:24396205

  11. Risk factors associated with structural postural changes in the spinal column of children and adolescents

    PubMed Central

    Sedrez, Juliana Adami; da Rosa, Maria Izabel Zaniratti; Noll, Matias; Medeiros, Fernanda da Silva; Candotti, Claudia Tarragô

    2015-01-01

    OBJECTIVE: To investigate the association between behavioral risk factors, specifically postural habits, with the presence of structural changes in the spinal column of children and adolescents. METHODS: 59 students were evaluated through the self-reporting Back Pain and Body Posture Evaluation Instrument and spinal panoramic radiographic examination. Spine curvatures were classified based on Cobb angles, as normal or altered in the saggital plane and as normal or scoliotic in the frontal plane. Data were analyzed using SPSS 18.0, based on descriptive statistics and chi-square association test (a=0,05). RESULTS: The prevalence of postural changes was 79.7% (n=47), of which 47.5% (n=28) showed frontal plane changes and 61% (n=36) sagital plane changes. Significant association was found between the presence of thoracic kyphosis and female gender, practice of physical exercises only once or twice a week, sleep time greater than 10 hours, inadequate postures when sitting on a seat and sitting down to write, and how school supplies are carried. Lumbar lordosis was associated with the inadequate way of carrying the school backpack (asymmetric); and scoliosis was associated wuth the practice of competitive sports and sleep time greater than 10 hours. CONCLUSIONS: Lifestyle may be associated with postural changes. It is important to develop health policies in order to reduce the prevalence of postural changes, by decreasing the associated risk factors. PMID:25623725

  12. [Risk factors associated with structural postural changes in the spinal column of children and adolescents].

    PubMed

    Sedrez, Juliana Adami; da Rosa, Maria Izabel Zaniratti; Noll, Matias; Medeiros, Fernanda da Silva; Candotti, Claudia Tarragô

    2015-01-01

    To investigate the association between behavioral risk factors, specifically postural habits, with the presence of structural changes in the spine of children and adolescents. 59 students were evaluated through the self-reporting Back Pain and Body Posture Evaluation Instrument e and the spine panoramic radiographic examination. The spine curvatures were classified, based on Cobb' angle, as normal or altered in the saggital plane and as normal or scoliotic in the frontal plane. Data were analyzed using SPSS 18.0, from descriptive statistics and chi-square association test (α=0,05). The prevalence of postural alterations was 79.7% (n=47), of which 47.5% (n=28) showed frontal plane alterations and 61% (n=36) sagital plane alterations. Significant association was found between the presence of thoracic kyphosis and female gender, practice of physical exercise only once or twice a week, sleep time greater than 10 hours, inappropriate postures to sit on the bench and sit down to write, and transport of school supplies. Lumbar lordosis was associated with improperly transportation of school backpack (asymmetric); and scoliosis was associated with the practice of competitive sport and sleep time greater than 10 hours. Lifestyle may be associated with postural alterations. It is important to develop health policies in order to reduce the prevalence of postural alterations with a reduction of associated risk factors. Copyright © 2014 Associação de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

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

    PubMed Central

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  15. Increased gain of vestibulospinal potentials evoked in neck and leg muscles when standing under height-induced postural threat.

    PubMed

    Naranjo, E N; Allum, J H J; Inglis, J T; Carpenter, M G

    2015-05-07

    To measure changes in amplitudes of vestibular evoked myogenic potentials (VEMPs) elicited from neck, upper and lower limb muscles during a quiet standing task with increased postural threat achieved by manipulating surface height. Twenty eight subjects were tested while standing on a platform raised to 0.8 m and 3.2 m from the ground. Surface electromyography was recorded from the ipsilateral sternocleidomastoid (SCM), biceps brachii (BB), flexor carpi radialis (FCR), soleus (SOL) and medial gastrocnemius (MG) muscles. Stimulation was with air-conducted short tone bursts (4 ms). After controlling for background muscle activity, VEMP amplitudes were compared between heights and correlated with changes in state anxiety, fear and arousal. VEMP amplitude significantly increased in SCM (9%) and SOL (12.7%) with increased surface height (p<0.05). These modest increases in SCM VEMP amplitude were significantly correlated with anxiety (Rho=0.57, p=0.004) and confidence (Rho=-0.38, p=0.047) and those for SOL were significantly correlated with anxiety (Rho=0.33, p=0.049) and fear (Rho=0.36, p=0.037). Postural threat significantly increased vestibulospinal reflex (VSR) gains. Results demonstrate that VEMPs can be used to test different VSR pathways simultaneously during stance. Since fear and anxiety are prevalent with vestibular disorders, they should be considered as potential contributing factors for clinical vestibular outcome measures. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Relation between the Sensory and Anthropometric Variables in the Quiet Standing Postural Control: Is the Inverted Pendulum Important for the Static Balance Control?

    PubMed Central

    Alonso, Angélica C.; Mochizuki, Luis; Silva Luna, Natália Mariana; Ayama, Sérgio; Canonica, Alexandra Carolina; Greve, Júlia M. D. A.

    2015-01-01

    The aim of this study was to evaluate the relation between the sensory and anthropometric variables in the quiet standing. Methods. One hundred individuals (50 men, 50 women; 20–40 years old) participated in this study. For all participants, the body composition (fat tissue, lean mass, bone mineral content, and bone mineral density) and body mass, height, trunk-head length, lower limb length, and upper limb length were measured. The center of pressure was measured during the quiet standing posture, the eyes opened and closed with a force platform. Correlation and regression analysis were run to analyze the relation among body composition, anthropometric data, and postural sway. Results. The correlation analysis showed low relation between postural sway and anthropometric variables. The multiple linear regression analyses showed that the height explained 12% of the mediolateral displacement and 11% of the center of pressure area. The length of the trunk head explained 6% of displacement in the anteroposterior postural sway. During eyes closed condition, the support basis and height explained 18% of mediolateral postural sway. Conclusion. The postural control depends on body composition and dimension. This relation is mediated by the sensory information. The height was the anthropometric variable that most influenced the postural sway. PMID:26539550

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

    PubMed

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

    2010-07-26

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

  18. Postural Stability During Standing Balance and Sit-to-Stand in Master Athlete Runners Compared With Non-Athletic Old and Young Adults.

    PubMed

    Leightley, Daniel; Yap, Moi Hoon; Coulson, Jessica; Piasecki, Mathew; Cameron, James; Barnouin, Yoann; Tobias, Jon; McPhee, Jamie S

    2016-10-21

    The aim of this study was to compare postural sway during a series of static balancing tasks and during five chair rises between healthy young (mean (SEM) age 26(1) yrs), healthy old (age 67(1) yrs) and master athlete runners (age 67(1) yrs; competing and training for the previous 51(5) yrs) using the Microsoft Kinect One. The healthy old had more sway than young in all balance tasks. The master athletes had similar sway to young during two-leg balancing and one leg standing with eyes open. When balancing on one-leg with eyes closed, both the healthy old and the master athletes had around 17-fold more sway than young. The healthy old and master athletes also had less anterio-posterior movement during chair rising compared with young. These results suggest that masters runners are not spared from the age-associated decline in postural stability and may benefit from specific balance training.

  19. Improvement in Functioning and Psychological Distress in Adolescents With Postural Orthostatic Tachycardia Syndrome Following Interdisciplinary Treatment.

    PubMed

    Bruce, Barbara K; Harrison, Tracy E; Bee, Susan M; Luedtke, Connie A; Porter, Co-Burn J; Fischer, Philip R; Hayes, Sarah E; Allman, Daniel A; Ale, Chelsea M; Weiss, Karen E

    2016-03-15

    Significant functional impairment and psychological distress have been observed in adolescent patients with postural orthostatic tachycardia syndrome (POTS). Interdisciplinary rehabilitation programs have been shown to be beneficial in the treatment of chronic pain in adults and adolescents. Only preliminary data have examined interdisciplinary rehabilitation efforts in patients with POTS. This study evaluated the impact of an interdisciplinary rehabilitation program on the functional impairment and psychological distress in 33 adolescents diagnosed with POTS. Patients included in the study were adolescents ages 11 to 18 diagnosed with POTS. Measures completed at admission and discharge from the program included the Functional Disability Index, Center for Epidemiological Studies-Depression-Child scale, and the Pain Catastrophizing Scale for Children. After participation in the 3-week program, adolescents with POTS demonstrated a significant increase in overall functional ability and significant reductions in depression and catastrophizing.

  20. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered.

    PubMed

    Pialasse, Jean-Philippe; Descarreaux, Martin; Mercier, Pierre; Blouin, Jean; Simoneau, Martin

    2015-01-01

    Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20) or severe (n = 16) spine deformation were compared to those of healthy control adolescents (n = 16). Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes.

  1. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered

    PubMed Central

    Pialasse, Jean-Philippe; Descarreaux, Martin; Mercier, Pierre; Blouin, Jean; Simoneau, Martin

    2015-01-01

    Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20) or severe (n = 16) spine deformation were compared to those of healthy control adolescents (n = 16). Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes. PMID:26580068

  2. Spherical lenses and prisms lead to postural instability in both dyslexic and non dyslexic adolescents.

    PubMed

    Kapoula, Zoi; Gaertner, Chrystal; Matheron, Eric

    2012-01-01

    There is controversy as to whether dyslexic children present systematic postural deficiency. Clinicians use a combination of ophthalmic prisms and proprioceptive soles to improve postural performances. This study examines the effects of convergent prisms and spherical lenses on posture. Fourteen dyslexics (13-17 years-old) and 11 non dyslexics (13-16 years-old) participated in the study. Quiet stance posturography was performed with the TechnoConcept device while subjects fixated a target at eye-level from a distance of 1_m. Four conditions were run: normal viewing; viewing the target with spherical lenses of -1 diopter (ACCOM1) over each eye; viewing with -3 diopters over each eye (ACCOM3); viewing with a convergent prism of 8 diopters per eye. Relative to normal viewing, the -1 lenses increased the surface of body sway significantly whereas the -3 diopter lenses only resulted in a significant increase of antero-posterior body sway. Thus, adolescents would appear to cope more effectively with stronger conflicts rather than subtle ones. The prism condition resulted in a significant increase in both the surface and the antero-posterior body sway. Importantly, all of these effects were similar for the two groups. Wavelet analysis (time frequency domain) revealed high spectral power of antero-posterior sway for the prism condition in both groups. In the ACCOM3 condition, the spectral power of antero-posterior sway decreased for non dyslexics but increased for dyslexics suggesting that dyslexics encounter more difficulty with accommodation. The cancelling time for medium range frequency (believed to be controlled by the cerebellum), was shorter in dyslexics, suggesting fewer instances of optimal control. We conclude that dyslexics achieve similar postural performances albeit less efficiently. Prisms and lenses destabilize posture for all teenagers. Thus, contrary to adults, adolescents do not seem to use efferent, proprioceptive ocular motor signals to improve their

  3. Spherical Lenses and Prisms Lead to Postural Instability in Both Dyslexic and Non Dyslexic Adolescents

    PubMed Central

    Kapoula, Zoi; Gaertner, Chrystal; Matheron, Eric

    2012-01-01

    There is controversy as to whether dyslexic children present systematic postural deficiency. Clinicians use a combination of ophthalmic prisms and proprioceptive soles to improve postural performances. This study examines the effects of convergent prisms and spherical lenses on posture. Fourteen dyslexics (13–17 years-old) and 11 non dyslexics (13–16 years-old) participated in the study. Quiet stance posturography was performed with the TechnoConcept device while subjects fixated a target at eye-level from a distance of 1_m. Four conditions were run: normal viewing; viewing the target with spherical lenses of −1 diopter (ACCOM1) over each eye; viewing with −3 diopters over each eye (ACCOM3); viewing with a convergent prism of 8 diopters per eye. Relative to normal viewing, the −1 lenses increased the surface of body sway significantly whereas the −3 diopter lenses only resulted in a significant increase of antero-posterior body sway. Thus, adolescents would appear to cope more effectively with stronger conflicts rather than subtle ones. The prism condition resulted in a significant increase in both the surface and the antero-posterior body sway. Importantly, all of these effects were similar for the two groups. Wavelet analysis (time frequency domain) revealed high spectral power of antero-posterior sway for the prism condition in both groups. In the ACCOM3 condition, the spectral power of antero-posterior sway decreased for non dyslexics but increased for dyslexics suggesting that dyslexics encounter more difficulty with accommodation. The cancelling time for medium range frequency (believed to be controlled by the cerebellum), was shorter in dyslexics, suggesting fewer instances of optimal control. We conclude that dyslexics achieve similar postural performances albeit less efficiently. Prisms and lenses destabilize posture for all teenagers. Thus, contrary to adults, adolescents do not seem to use efferent, proprioceptive ocular motor signals to

  4. Association between home posture habits and low back pain in high school adolescents.

    PubMed

    Meziat Filho, Ney; Coutinho, Evandro Silva; Azevedo e Silva, Gulnar

    2015-03-01

    To investigate the prevalence of low back pain (LBP) and the association with home posture habits while watching TV and using the computer in adolescents. This is a cross-sectional study with high school adolescents in Rio de Janeiro, Brazil. Students answered questions regarding sociodemographic variables, lifestyle, posture (illustration), time watching TV, time using computer, time playing video game and the presence and impact of LBP. Multivariate logistic regression was used to investigate the association between home posture habits and LBP. The prevalence of LBP was 46.8 % (18.2 % chronic low back pain [CLBP] and 28.6 % acute low back pain [ALBP]). As LBP consequence, 23 % (n = 253) of the students took medication, 9.1 % (n = 100) missed classes and 8.2 % (n = 90) sought a physician. Slump postures while watching TV and using the desktop computer were associated with CLBP (OR 3.22, 95 % CI 1.38-7.5 and OR 1.7, 95 % CI 1.06-2.73, respectively). Participants who watched TV seated in bed yielded an OR of 2.14 (95 % CI 1.06-4.32) for ALBP and who used the notebook lying belly down in bed yielded an odds ratio (OR) of 2.26 (95 % CI 1.02-5.01) for ALBP. Among confounding factors, female sex was associated with CLBP and ALBP, work (no) was a protective factor associated with ALBP. Our findings support the high prevalence and the substantial impact of LBP in late adolescence and add the association with inappropriate home postural habits.

  5. Postural stability with exhaustive repetitive sit-to-stand exercise in young adults.

    PubMed

    Bryanton, Megan A; Bilodeau, Martin

    2016-10-01

    Previous research has indicated that muscle fatigue due to repeated bouts of physical activity can have negative residual effects on balance; however investigations using multi-joint forms of exercise involved in everyday settings and determination of how control of posture is altered during the physical activity itself are limited. The purpose of this investigation was to evaluate alterations in postural stability before, during, and after prolonged multi-joint STS exercise in healthy young adults. Center of pressure (COP) acquisitions were collected during repetitive STS exercise, while voluntary limits of stability (LOS) testing was performed before, immediately after, and 10min after STS exercise. By 50% total STS exercise time, fatigue resulted in increased anterio-posterior (y) and medio-lateral (x) COP path lengths (p=0.003 and p=0.018 respectively) and an anterior shift of COP at seat-off towards the mid-foot (p=0.010). No significant change in LOS mean amplitude was found after STS exercise; however a significant fatigue effect resulted in increased COPy sway velocity at maximal lean positions (p=0.006), but returned to PRE values after 10min of rest. Declines in postural stability during repetitive STS exercise was associated with reduced control of COP, as well as a reduced ability to stably control COP at extreme postural limits; however, 10min was adequate in young adults for recovery. These results may have important implications for monitoring fall risk due to acute bouts of exercise induced muscle fatigue from repetitive multi-joint activities such as the STS.

  6. Early Adolescent Romantic Partner Status, Peer Standing, and Problem Behaviors.

    PubMed

    Miller, Shari; Lansford, Jennifer E; Costanzo, Philip; Malone, Patrick S; Golonka, Megan; Killeya-Jones, Ley A

    2009-12-01

    This study examined associations among early adolescent romantic relationships, peer standing, problem behaviors, and gender as a moderator of these associations, in a sample of 320 seventh-grade students. Popular and controversial status youth were more likely to have a romantic partner, whereas neglected status youth were less likely to have a romantic partner. Similarly, youth perceived as conventional and unconventional leaders were also more likely to have a romantic partner than were non-leaders. Youth who had a romantic partner drank more alcohol and were more aggressive than were youth who did not have a romantic partner. Among those youth who had romantic partners, those who reported having more deviance-prone partners were themselves more likely to use alcohol and to be more aggressive, and those who engaged in deviant behavior with their partners used more alcohol. However, these associations varied somewhat by gender. These findings underscore the salience of early romantic partner relationships in the adjustment of early adolescents.

  7. Outcomes in adolescents with postural orthostatic tachycardia syndrome treated with midodrine and beta-blockers.

    PubMed

    Lai, Cindy C; Fischer, Philip R; Brands, Chad K; Fisher, Jennifer L; Porter, Co-Burn J; Driscoll, Sherilyn W; Graner, Kevin K

    2009-02-01

    Postural orthostatic tachycardia syndrome (POTS) is associated with debilitating fatigue, dizziness, and discomfort in previously healthy adolescents. The effects of medical therapy have not been well studied in this patient population. This study assessed the relative efficacy and impact of drug therapy on the functioning and quality of life in adolescents with POTS. A retrospective, single center, chart review analysis with a follow-up written survey was conducted on a group of 121 adolescents who had undergone autonomic reflex screening at the Mayo Clinic from 2002 to 2005 as part of an evaluation for possible POTS. Of 121 surveys sent, 47 adolescents returned a completed survey. In this cohort of patients, the two most commonly prescribed drug therapies were midodrine (n = 13) and beta-blockers (n = 14). Patients in the midodrine group were comparable to patients in the beta-blocker group in gender, age, pretreatment postural heart rate changes, and months from initial evaluation to survey completion. More patients treated with a beta-blocker reported improvement after visiting Mayo Clinic (100% vs 62%, P = 0.016) and more attributed their progress to medication (63.6% vs 36.4%, P = 0.011) than did those treated with midodrine. Treatment with both midodrine and beta-blockers was associated with overall improvement in POTS patients' general health; however, adolescents taking beta-blockers were more likely than those taking midodrine to credit the role of medications in their improvement.

  8. Ankle-joint mobility and standing squat posture in elite junior cross-country skiers. A pilot study.

    PubMed

    Conradsson, D; Fridén, C; Nilsson-Wikmar, L; Ang, B O

    2010-06-01

    Skating technique in cross-country skiing is a complex multi-joint movement with kinematics comparable to those of the standing squat exercise where any restricted joint mobility in the lower extremity-chain may change the movement pattern. The aim of this pilot study was to investigate the effect of ankle mobility on trunk posture during squat exercise in cross-country skiers. Seven elite junior cross-country skiers (age range 17-19 years) performed two different standing squats, one with hands on hips and one with arms extended above the head. The squats were recorded on video and analyzed in selected positions: 90 degrees and maximal knee flexion. Segment angles for shank and trunk were calculated from anatomical references relative to vertical/horizontal orientation in space. Recordings from passive ankle dorsiflexion were correlated with 1) trunk flexion, and 2) angle index (trunk flexion relative to shank angle). Reduced ankle dorsiflexion was moderately associated with increased trunk flexion with hands on hips (r=-0.51 to -0.57), and arms above head (r=-0.61 to -0.64). Further, reduced dorsiflexion was also moderately associated with decreased angle index with hands on hip (r=0.60 to 0.67) but highly associated with decreased angle index with arms above head (r=0.75 to 0.76). The results imply that reduced ankle dorsal mobility is related to decreased angle index as well as increased trunk flexion during squat exercise, thus indicating the relevance of good ankle joint mobility for appropriate upper-body posture during squat exercise.

  9. One- or Two-Legged Standing: What Is the More Suitable Protocol to Assess the Postural Effects of the Rigid Ankle Orthosis?

    ERIC Educational Resources Information Center

    Rougier, Patrice; Genthon, Nicolas; Gallois-Montbrun, Thibault; Brugiere, Steve; Bouvat, Eric

    2009-01-01

    To highlight the capacity of one- and two-legged standing protocols when assessing postural behavior induced by a rigid ankle orthosis, 14 healthy individuals stood upright barefoot and wore either an elastic stocking on the preferred leg or a rigid orthosis with or without additional taping in one- or two-legged (TL) conditions. Traditional…

  10. One- or Two-Legged Standing: What Is the More Suitable Protocol to Assess the Postural Effects of the Rigid Ankle Orthosis?

    ERIC Educational Resources Information Center

    Rougier, Patrice; Genthon, Nicolas; Gallois-Montbrun, Thibault; Brugiere, Steve; Bouvat, Eric

    2009-01-01

    To highlight the capacity of one- and two-legged standing protocols when assessing postural behavior induced by a rigid ankle orthosis, 14 healthy individuals stood upright barefoot and wore either an elastic stocking on the preferred leg or a rigid orthosis with or without additional taping in one- or two-legged (TL) conditions. Traditional…

  11. Pain and Posture of Children and Adolescents Who Learn the Accordion as Compared with Non-Musician Students.

    PubMed

    Aparicio, Liliana; Lã, Filipa Mb; Silva, Anabela G

    2016-12-01

    This study assessed the effect of practicing the accordion on pain and posture of children and adolescent students. Pain and posture (forward head posture, scapular posture, and lumbar lordosis) were compared between two groups of preparatory and secondary school students, matched for age and sex: those who took accordion lessons (accordionists, n=16) and those who never studied a musical instrument (non-musicians, n=16). Students taking accordion lessons reported significantly more pain in the shoulder, wrist/hand, and thoracic regions (p<0.05), showed significantly more forward head posture (accordionists, median ± interquartile distance [IQ] distance = 35.6° ± 7.8°; non-musicians = 45.3° ± 10.8°; p<0.05), and significantly increased lumbar lordosis (accordionists, median ± IQ distance = 55.5° ± 30.6°; nonmusicians = 39.0° ± 3.9°; p<0.05). No significant differences were found for scapular posture between groups. This study suggests that children and adolescents who play the accordion have an increased forward head posture and lumbar lordosis and a tendency to report more pain than children and adolescents who do not play a musical instrument. Results corroborate the need for including healthy preventive teaching-learning strategies at music conservatoires.

  12. Center of Mass Acceleration Feedback Control of Standing Balance by Functional Neuromuscular Stimulation against External Postural Perturbations

    PubMed Central

    Nataraj, Raviraj; Audu, Musa L.; Triolo, Ronald J.

    2013-01-01

    This study investigated the use of center of mass (COM) acceleration feedback for improving performance of a functional neuromuscular stimulation (FNS) control system to restore standing function to a subject with complete, thoracic-level spinal cord injury (SCI). The approach for linearly relating changes in muscle stimulation to changes in COM acceleration was verified experimentally and subsequently produced data to create an input-output map driven by sensor feedback. The feedback gains were systematically tuned to reduce upper extremity (UE) loads applied to an instrumented support device while resisting external postural disturbances. Total body COM acceleration was accurately estimated (> 89% variance explained) using three-dimensional (3-D) outputs of two accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, feedback control of stimulation reduced UE loading by 33%. COM acceleration feedback is advantageous in constructing a standing neuroprosthesis since it provides the basis for a comprehensive control synergy about a global, dynamic variable and requires minimal instrumentation. Future work should include tuning and testing the feedback control system during functional reaching activity that is more indicative of activities of daily living. PMID:22987499

  13. Effect of frequency, magnitude and direction of translational and rotational oscillation on the postural stability of standing people

    NASA Astrophysics Data System (ADS)

    Nawayseh, Naser; Griffin, Michael J.

    2006-12-01

    Oscillatory motions can cause injury in transport when standing passengers or crew lose balance and fall. To predict the loss of balance of standing people, a model is required of the relationship between the input motion and the stability of the human body. This experimental study investigated the effect of frequency, magnitude and direction of oscillation on the postural stability of standing subjects and whether response to rotational oscillation can be predicted from knowledge of response to translational oscillation. Twelve male subjects stood on a floor that oscillated in either horizontal (fore-and-aft or lateral) or rotational (pitch or roll) directions. The oscillations were one-third octave bands of random motion centred on five preferred octave centre frequencies (0.125, 0.25, 0.5, 1.0, and 2.0 Hz). The horizontal motions were presented at each of four velocities (0.04, 0.062, 0.099, and 0.16 ms -1 rms) and the rotational motions were presented at each of four rotational angles (0.73, 1.46, 2.92, and 5.85° rms) corresponding to four accelerations (0.125, 0.25, 0.5, and 1.0 ms -2 rms), where the acceleration is that caused by rotation through the gravitational vector. Postural stability was determined by subjective methods and by measuring the displacement of the centre of pressure at the feet during horizontal oscillation. During horizontal oscillation, increases in motion magnitude increased instability and, with the same velocity at all frequencies from 0.125 to 2.0 Hz, most instability occurred in the region of 0.5 Hz. Fore-and-aft oscillation produced more instability than lateral oscillation, although displacements of the centre of pressure were similar in both directions. With the same angular displacement at all frequencies from 0.125 to 2.0 Hz, pitch oscillation caused more instability than roll oscillation, but in both directions instability increased with increased frequency of oscillation. Frequency weightings for acceleration in the plane of

  14. Craniofacial and cervical morphology related to sagittal spinal posture in children and adolescents.

    PubMed

    Segatto, Emil; Segatto, Angyalka; Braunitzer, Gábor; Kirschneck, Christian; Fanghänel, Jochen; Danesh, Gholamreza; Lippold, Carsten

    2014-01-01

    Studies on the relationship between body posture and craniofacial parameters often focus on the cervical spine. Thus, less attention has been paid to the morphology of the vertebra C2 that serves as both a structural and functional link between the craniofacial area and the other part of the spine. The objective of this study was to assess the relation of craniofacial features to certain morphological and positional characteristics of the cervical vertebrae and the spine during growth. We determined body posture indices for 69 children and adolescents by means of a radiation-free method (rasterstereography). The morphological and positional analysis of the craniofacial area and the cervical vertebrae was based on standardized lateral X-ray cephalograms. Medium to strong correlations were found between body posture, C2 morphology, and craniofacial parameters. We found significant correlations between the C2 dens axis height and maxillary indices as well as between the C2 dens axis inclination and cephalometrical values of the mandibular area. Similarly the correlation between the C2 dens axis inclination and the postural index flèche cervicale was highly significant (P < 0.05, r = 0.333). These results suggest that morphological features of the odontoid process may serve as valuable predictive markers in interdisciplinary orthopedic-orthodontic diagnostics.

  15. Craniofacial and Cervical Morphology Related to Sagittal Spinal Posture in Children and Adolescents

    PubMed Central

    Segatto, Angyalka; Braunitzer, Gábor

    2014-01-01

    Studies on the relationship between body posture and craniofacial parameters often focus on the cervical spine. Thus, less attention has been paid to the morphology of the vertebra C2 that serves as both a structural and functional link between the craniofacial area and the other part of the spine. The objective of this study was to assess the relation of craniofacial features to certain morphological and positional characteristics of the cervical vertebrae and the spine during growth. We determined body posture indices for 69 children and adolescents by means of a radiation-free method (rasterstereography). The morphological and positional analysis of the craniofacial area and the cervical vertebrae was based on standardized lateral X-ray cephalograms. Medium to strong correlations were found between body posture, C2 morphology, and craniofacial parameters. We found significant correlations between the C2 dens axis height and maxillary indices as well as between the C2 dens axis inclination and cephalometrical values of the mandibular area. Similarly the correlation between the C2 dens axis inclination and the postural index flèche cervicale was highly significant (P < 0.05, r = 0.333). These results suggest that morphological features of the odontoid process may serve as valuable predictive markers in interdisciplinary orthopedic-orthodontic diagnostics. PMID:25276804

  16. Effects of balance training on postural sway, leg extensor strength, and jumping height in adolescents.

    PubMed

    Granacher, Urs; Gollhofer, Albert; Kriemler, Susi

    2010-09-01

    Deficits in strength of the lower extremities and postural control have been associated with a high risk of sustaining sport-related injuries. Such injuries often occur during physical education (PE) classes and mostly affect the lower extremities. Thus, the objectives of this study were to investigate the effects of balance training on postural sway, leg extensor strength, and jumping height in adolescents. Twenty high school students participated in this study and were assigned to either an intervention (n = 10) or control group (n = 10). The intervention group participated in a 4-week balance-training program integrated in their physical education lessons. Pre- and posttests included the measurements of postural sway on a balance platform, jumping height on a force platform, and maximal isometric leg extension force on a leg-press. Balance training resulted in significantly improved postural control, increased jumping height, and enhanced rate of force development of the leg extensors. Physiological adaptations rather than learning effects seem to be responsible for the observed findings. These results could have an impact on improving the performance level in various sports and on reducing the injury prevalence of the lower extremities.

  17. Reliability and Validity Measurement of Sagittal Lumbosacral Quiet Standing Posture with a Smartphone Application in a Mixed Population of 183 College Students and Personnel

    PubMed Central

    Nikoloudaki, Maria; Thacheth, Sara; Zagli, Kalliroi; Bitrou, Konstantina; Nigritinos, Andreas; Botton, Leon

    2016-01-01

    Accurate recording of spinal posture with simple and accessible measurement devices in clinical practice may lead to spinal loading optimization in occupations related to prolonged sitting and standing postures. Therefore, the purpose of this study was to establish the level of reliability of sagittal lumbosacral posture in quiet standing and the validity of the method in differentiating between male and female subjects, establishing in parallel a normative database. 183 participants (83 males and 100 females), with no current low back or pelvic pain, were assessed using the “iHandy Level” smartphone application. Intrarater reliability (3 same-day sequential measurements) was high for both the lumbar curve (ICC2,1: 0.96, SEM: 2.13°, and MDC95%: 5.9°) and the sacral slope (ICC2,1: 0.97, SEM: 1.61°, and MDC95%: 4.46°) sagittal alignment. Data analysis for each gender separately confirmed equally high reliability for both male and female participants. Correlation between lumbar curve and sacral slope was high (Pearson's r = 0.86, p < 0.001). Between-gender comparisons confirmed the validity of the method to differentiate between male and female lumbar curve and sacral slope angles, with females generally demonstrating greater lumbosacral values (p < 0.001). The “iHandy Level” application is a reliable and valid tool in the measurement of lumbosacral quiet standing spinal posture in the sagittal plane. PMID:27843650

  18. Postural control during sit-to-stand movement and its relationship with upright position in children with hemiplegic spastic cerebral palsy and in typically developing children

    PubMed Central

    Pavão, Silvia L.; Santos, Adriana N.; Oliveira, Ana B.; Rocha, Nelci A. C. F.

    2015-01-01

    OBJECTIVE: The purpose of this study was to compare postural control in typically developing (TD) children and children with cerebral palsy (CP) during the sit-to-stand (STS) movement and to assess the relationship between static (during static standing position) and dynamic postural control (during STS movement) in both groups. METHOD: The center of pressure (CoP) behavior of 23 TD children and 6 children with spastic hemiplegic CP (Gross Motor Function Classification System [GMFCS] I and II) was assessed during STS movement performance and during static standing conditions with the use of a force plate. The data obtained from the force plate were used to calculate CoP variables: anteroposterior (AP) and mediolateral (ML) amplitudes of CoP displacement and the area and velocity of CoP oscillation. RESULTS: According to the Mann-Whitney test, children with CP exhibited higher CoP values in all of the analyzed variables during the beginning of STS movement. Pearson's correlation verified a positive correlation between the CoP variables during both static conditions and the performance of STS movement. CONCLUSIONS: Children with spastic hemiplegic CP present major postural oscillations during the beginning of STS movement compared with typical children. Moreover, the observed relationship between postural control in static and dynamic conditions reveals the importance of body control in the static position for the performance of functional activities that put the body in motion, such as STS movement. PMID:25651131

  19. Evaluation of postural control in quiet standing using center of mass acceleration: comparison among the young, the elderly, and people with stroke.

    PubMed

    Yu, Erkang; Abe, Masaki; Masani, Kei; Kawashima, Noritaka; Eto, Fumio; Haga, Nobuhiko; Nakazawa, Kimitaka

    2008-06-01

    To determine center of mass (COM) acceleration usefulness in the evaluation of postural control during quiet standing. Three-group comparison design. A research laboratory. Poststroke subjects (n=12), healthy elderly subjects (n=22), and healthy young subjects (n=25). Not applicable. With a force platform, postural sway was evaluated by using the standard deviations of COM acceleration and center of pressure (COP) and COM (COP-COM) in which COP-COM represents the distance between the COP and the COM. COM acceleration and COP-COM variables were greater in the poststroke group than in the healthy groups (elderly and young) in the mediolateral (ML) direction. Both variables in the anteroposterior (AP) direction were greater in the poststroke group and the elderly group than in the young group. Furthermore, the correlations between COM acceleration and COP-COM in each group in each direction were shown to be significantly high (r range, .906-.979; P<.001). COM acceleration was useful in the evaluation of postural control during quiet standing when comparing the young, the elderly, and poststroke patients. Additionally, COM acceleration and COP-COM in both the AP and ML directions during quiet standing were significantly and highly correlated. Thus, we proposed that COM acceleration can be an alternative and convenient measure instead of COP-COM in the evaluation of postural control.

  20. Effect of neck and trunk rotation speeds on cerebral cortex activity and standing postural stability: a functional near-infrared spectroscopy study.

    PubMed

    Mitsutake, Tsubasa; Sakamoto, Maiko; Horikawa, Etsuo

    2015-09-01

    [Purpose] The aim of the present study was to determine whether different neck and trunk rotation speeds influence standing postural stability or frontal and temporal cortical activity during rotation in healthy young adults. [Subjects and Methods] Twelve healthy volunteers participated in this study. A custom turn-table operated by one of the experimenters was placed on a platform to assess postural perturbation. Subjects were asked to stand barefoot on the turn-table in an upright position with their feet together, and measurements were obtained during high- and low-speed rotations. Postural stability was tested using a force platform and a head sensor. Cerebral cortex activity was measured using functional near-infrared spectroscopy. Brain activity, center of pressure, and head perturbation were measured simultaneously for each subject. [Results] Significant differences were found in the center of pressure and the head angular velocity between high- and low-speed rotations. However, compared to baseline, oxygenated hemoglobin levels were not significantly different during high- or low-speed rotations. [Conclusion] Automatic postural responses to neck and trunk rotation while standing did not significantly activate the cerebral cortex. Therefore, the response to stimuli from the feet may be controlled by the spinal reflex rather than the cerebral cortex.

  1. [Influence of Achilles tendon vibration on the human vertical posture during standing with asymmetrical leg loading].

    PubMed

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

    2014-01-01

    The shift of center of pressure (CP) of body and CP of each leg was studied during Achilles tendon vibration of one or both legs while subject was standing with symmetrical load on the legs or with the load transferred on one leg. The CP shift of standing subject during unilateral Achilles tendon vibration depended both on the side of the tendon vibration and on the leg load. When standing with a load transferred on one leg the shift of common CP was larger than when the vibration was applied to the loaded leg. The CP shift of one leg was greater if the vibration, and the load was applied to it. Vibration of unloaded leg caused a CP shift in the contralateral loaded leg. In this case, the vibration of left unloaded leg caused no noticeable CP shift of left leg, while the vibration of the unloaded right leg caused CP shift of right foot. In the same conditions of load and vibration the CP displacement of right leg was larger than the CP shift of left foot. It can be assumed that the change in the load on the leg and unilateral vibration of leg muscles change of the internal representation of the vertical body axis, which affects the CP position of one leg during the muscles vibration.

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

    PubMed Central

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

    It has been shown that increased muscular activity along the trunk is likely to impair body balance, but there is little knowledge about its consequences on more dynamic tasks. The purpose of this study was to determine the effect of unilateral and bilateral increases of muscular tension along the trunk on the sit-to-stand task (STS) performance and associated anticipatory postural adjustments (APAs). Twelve healthy females (23 ± 3 years, 163 ± 0.06 cm, 56 ± 9 kg), free of any neurological or musculoskeletal disorders, performed six trials of the STS at maximum speed, in seven experimental conditions varying the muscular tension along each side of the trunk, using a specific bimanual compressive load paradigm. A six-channel force plate was used to calculate the coordinates of the center of pressure (CP) along the anterior-posterior and medial-lateral axes, and the kinematics of the head, spine and pelvis, were estimated using three pairs of uni-axial accelerometers. The postural and focal components of the task were assessed using three biomechanical parameters calculated from CP signals: the duration and magnitude of APAs, and the duration of focal movement (dFM). Results showed that beyond a given level, higher muscular tension along the trunk results in longer APAs, but with a stable duration of the focal movement. In addition, no significant variation of APAs and FM parameters was found between bilateral and unilateral increases of muscular tension. It was suggested that restricted mobility due to higher muscular tension along the trunk requires an adaptation of the programming of APAs to keep the same level of performance in the STS task. These findings may have implications in treatment strategies aimed at preserving functional autonomy in pathologies including a rise of muscular tension. PMID:28220064

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

    PubMed

    Hamaoui, Alain; Alamini-Rodrigues, Caroline

    2017-01-01

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

  4. Assessment of the body posture of mouth-breathing children and adolescents.

    PubMed

    Conti, Patrícia Blau Margosian; Sakano, Eulália; Ribeiro, Maria Angela Gonçalves de Oliveira; Schivinski, Camila Isabel Santos; Ribeiro, José Dirceu

    2011-01-01

    To investigate associations between mouth breathing (MBr), nose breathing (NBr) and body posture classification and clinical variables in children and adolescents, by comparing patients with mouth breathing syndrome with a control group of similar age. This was an observational, analytical, controlled, cross-sectional study conducted at a university hospital. Children aged 5 years or more were recruited to one of two groups: healthy controls (NBr) or an MBr group. The MBr group comprised patients with a diagnosis of mouth breathing syndrome confirmed by clinical examination by a physician plus nasal endoscopy. The control group comprised healthy volunteers of the same age, with NBr confirmed by medical examination. All participants underwent postural assessment. Data were analyzed using the Mann-Whitney nonparametric test, the chi-square test and Fisher's exact test, to a significance level of 0.05%. A total of 306 MBr and 124 NBr were enrolled. Mouth breathers were more likely to be male (p = 0.0002), have more frequent and more severe nasal obstruction and larger tonsils (p = 0.0001) than NBr. Mouth breathers also exhibited higher incidence rates of allergic rhinitis (p = 0.0001), of thoracic respiratory pattern (p = 0.0001), high-arched palate (p = 0.0001) and unfavorable postural classifications (p = 0.0001) with relation to the control group. Postural classification scores were directly proportional to nasal obstruction (p = 0.0001) and male sex (p = 0.0008). Postural problems were significantly more common among children in the group with mouth breathing syndrome, highlighting the need for early interdisciplinary treatment of this syndrome.

  5. Effects of a Resistance and Stretching Training Program on Forward Head and Protracted Shoulder Posture in Adolescents.

    PubMed

    Ruivo, Rodrigo Miguel; Pezarat-Correia, Pedro; Carita, Ana Isabel

    2017-01-01

    The purpose of this study was to evaluate the effects of a 16-week resistance and stretching training program applied in physical education (PE) classes on forward head posture and protracted shoulder posture in Portuguese adolescents. This prospective, randomized, controlled study was conducted in 2 secondary schools. One hundred and thirty adolescents (aged 15-17 years) with forward head and protracted shoulder posture were randomly assigned to a control or experimental group. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and Postural Assessment Software. The American Shoulder and Elbow Surgeons Shoulder Assessment was used to assess shoulder pain, and neck pain during the last month was self-reported with a single question. These variables were assessed before and after a 16-week intervention period. The control group (n = 46) attended the PE classes, whereas the exercise group (n = 84) received a posture corrective exercise program in addition to PE classes. A significant increase in cervical and shoulder angles was observed in the intervention group from pretest to posttest (P < .05). For the shoulder pain scores in both groups, there were no significant changes after the 16 weeks. A 16-week resistance and stretching training program decreased forward head and protracted shoulder postures in adolescents. Copyright © 2017. Published by Elsevier Inc.

  6. Standing economy: does the heterogeneity in the energy cost of posture maintenance reside in differential patterns of spontaneous weight-shifting?

    PubMed

    Miles-Chan, Jennifer L; Fares, Elie-Jacques; Berkachy, Redina; Jacquet, Philippe; Isacco, Laurie; Schutz, Yves; Montani, Jean-Pierre; Dulloo, Abdul G

    2017-04-01

    Due to sedentarity-associated disease risks, there is much interest in methods to increase low-intensity physical activity. In this context, it is widely assumed that altering posture allocation can modify energy expenditure (EE) to impact body-weight regulation and health. However, we have recently shown the existence of two distinct phenotypes pertaining to the energy cost of standing-with most individuals having no sustained increase in EE during steady-state standing relative to sitting comfortably. Here, we investigated whether these distinct phenotypes are related to the presence/absence of spontaneous "weight-shifting", i.e. the redistribution of body-weight from one foot to the other. Using indirect calorimetry to measure EE in young adults during sitting and 10 min of steady-state standing, we examined: (i) heterogeneity in EE during standing (n = 36); (ii) EE and spontaneous weight-shifting patterns (n = 18); (iii) EE during spontaneous weight-shifting versus experimentally induced weight-shifting (n = 7), and; (iv) EE during spontaneous weight-shifting versus intermittent leg/body displacement (n = 6). Despite heterogeneity in EE response to steady-state standing, no differences were found in the amount or pattern of spontaneous weight-shifting between the two phenotypes. Whilst experimentally induced weight-shifting resulted in a mean EE increase of only 11% (range: 0-25%), intermittent leg/body displacement increased EE to >1.5 METs in all participants. Although the variability in spontaneous weight-shifting signatures between individuals does not appear to underlie heterogeneity in the energy cost of standing posture maintenance, these studies underscore the fact that leg/body displacement, rather than standing posture alone, is needed to increase EE above the currently defined sedentary threshold.

  7. What COP and Kinematic Parameters Better Characterize Postural Control in Standing Balance Tasks?

    PubMed

    Caballero, Carla; Barbado, David; Moreno, Francisco Javier

    2015-01-01

    The authors' aim was to determine which variables allow for the characterization of motor balance behavior. Traditional measures and nonlinear measures of center of pressure (COP; n = 30) and kinematics (n = 10) were tested in their absolute and relative consistency in a 30-s standing balance task protocol under stable and unstable conditions. Regarding COP variables, mean velocity (mVel), permutation entropy (PE) and detrended fluctuation analysis (DFA) exhibited high consistency between trials and ranked individuals more accurately compare with other metrics. In the kinematic signal mVel, PE and DFA had good intrasession reliability values in unstable conditions. Overall, the intrasession reliability values were better in the unstable condition than in the stable condition and the measures calculated using derived data had better intrasession reliability values. In conclusion, mVel, PE, and DFA allow for the good characterization of motor balance behavior in a simplified protocol where velocity time series are analyzed.

  8. The postural reaction to the drop of a hindlimb support in the standing cat remains following sensorimotor cortical ablation.

    PubMed

    Dufossé, M; Macpherson, J; Massion, J; Sybirska, E

    1985-04-19

    The postural response to an unexpected drop of either hindlimb platform was studied in the freely standing cat. The vertical forces, the forelimb electromyographic (EMG) activities and the movement of the trunk were analysed. A stereotyped diagonal pattern of support was observed. The imposed unloading of one hindlimb was followed by unloading of the diagonally opposite forelimb and loading of the two other limbs. In the ipsilateral loaded forelimb, the force increase is preceded by an activation of the biceps and is concomitant with a triceps coactivation. In the contralateral unloaded forelimb, reciprocal changes of biceps (activation) and triceps (inhibition) were observed and preceded the force decrease. Lateral or vertical displacement or rotation of the vertebral column at the high thoracic level, as evidenced by movie recording, began no earlier than 100 ms after the hindlimb drop and thus followed the EMG changes. Unilateral sensorimotor cortex ablation had no effect on this pattern or on the latencies of forelimb myographic responses. These results suggest that the hindlimb drop triggers stereotyped forelimb EMG responses which are organized centrally and that these responses are not mediated via a sensorimotor cortical loop.

  9. Physical exercise recommendations improve postural changes found in children and adolescents with cystic fibrosis: a randomized controlled trial.

    PubMed

    Schindel, Cláudia S; Hommerding, Patrícia X; Melo, Denizar A S; Baptista, Rafael R; Marostica, Paulo J C; Donadio, Márcio V F

    2015-03-01

    To evaluate postural changes and the distribution of plantar pressures in patients with cystic fibrosis (CF). We also sought to evaluate the effects of an educational guideline for physical activity on body posture in children and adolescents with CF. This was a 2-phase study of individuals between age 7 and 20 years. Phase I was a cross-sectional study in which healthy subjects were selected for postural evaluation and baropodometry, aiming to perform a later comparison with patients with CF. In phase II, we performed a randomized controlled clinical trial to assess the influence of the exercise guideline on the postural changes. Patients were assigned to 2 groups: control and intervention. The intervention consisted of a handbook with instructions for aerobic exercise and stretching. Main outcomes were postural abnormalities, plantar pressure distribution, and lung function. In phase I, 34 patients with CF and 34 healthy matched individuals were included. No significant baseline differences were identified. Children with CF presented more postural deviations compared with healthy subjects (P < .05), as to alignment of the head, shoulder girdle, and pelvis, increased cervical lordosis, and lateral chest distance. In phase II (n = 34), there were no baseline differences between groups. The intervention caused (P < .05) a decrease in cervical lordosis, thoracic kyphosis, lumbar lordosis, lateral chest distance, and abdominal protrusion, as well as in the baropodometric mean pressure and contact area. Children and adolescents with CF present postural changes when compared with healthy individuals. The educational guideline for exercise practice helped to improve posture, preventing the progression of some postural disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. What Makes a Bystander Stand By? Adolescents and Bullying

    ERIC Educational Resources Information Center

    Chapin, John; Brayack, Michael

    2016-01-01

    The current study sheds some light on the extent to which adolescents say they are experiencing bullying, what they think they would do when confronted with bullies, and what they have actually done in the past when witnessing bullying. Results from a survey of 1,742 adolescents indicates even young adolescents have already experienced verbal,…

  11. What Makes a Bystander Stand By? Adolescents and Bullying

    ERIC Educational Resources Information Center

    Chapin, John; Brayack, Michael

    2016-01-01

    The current study sheds some light on the extent to which adolescents say they are experiencing bullying, what they think they would do when confronted with bullies, and what they have actually done in the past when witnessing bullying. Results from a survey of 1,742 adolescents indicates even young adolescents have already experienced verbal,…

  12. Interpreting the posture and locomotion of Australopithecus afarensis: where do we stand?

    PubMed

    Ward, Carol V

    2002-01-01

    , but still do not falsify the null hypothesis. Disaptation, or negative selection, should result in a trait being reduced or lost. To infer the behaviors of a fossil species, we must first determine its adaptations, use this to make hypotheses about its behavior, and test these hypotheses using epigenetically sensitive traits that are modified by an individual's activity pattern. When the A. afarensis data are evaluated using this framework, it is clear that these hominins had undergone selection for habitual bipedality, but the null hypothesis of nonaptation to explain the retention of primitive, ape-like characters cannot be falsified at present. The apparent stasis in Australopithecus postcranial form is currently the strongest evidence for stabilizing selection maintaining its primitive features. Evidence from features affected by individual behaviors during ontogeny shows that A. afarensis individuals were habitually traveling bipedally, but evidence presented for arboreal behavior so far is not conclusive. By clearly identifying the questions we are asking about early hominin fossils, refining our knowledge about character polarities, and elucidating the factors influencing morphology, we will be able to progress in our understanding of the posture and locomotion of A. afarensis and all early hominins.

  13. Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies

    PubMed Central

    Wayne, Peter M.; Gow, Brian J.; Costa, Madalena D.; Peng, C.-K.; Lipsitz, Lewis A.; Hausdorff, Jeffrey M.; Davis, Roger B.; Walsh, Jacquelyn N.; Lough, Matthew; Novak, Vera; Yeh, Gloria Y.; Ahn, Andrew C.; Macklin, Eric A.; Manor, Brad

    2014-01-01

    Background Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale “complexity” of postural sway fluctuations. Objectives To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults. Methods A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up–and-Go tests characterized physical function. Results At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (P<0.001), and ML EC (P<0.001) conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018). Long- and short-term TC training were positively associated with physical function

  14. Symptoms predictive of postural tachycardia syndrome (POTS) in the adolescent headache patient.

    PubMed

    Heyer, Geoffrey L; Fedak, Erin M; LeGros, Aggie L

    2013-06-01

    To identify symptoms that may predict postural tachycardia syndrome (POTS) among adolescent patients with headache and lightheadedness referred for tilt table testing. Individuals with POTS can have a variety of symptoms that impair quality of life. The specific symptoms that help to distinguish the POTS patient in an adolescent headache population have not been determined. A group of symptoms was compared among 70 adolescent patients with headache and lightheadedness referred to a pediatric headache clinic for tilt table testing. Every patient completed a symptom questionnaire prior to the tilt table test. The chi-square test was used to compare questionnaire responses between patients found to have POTS and those who did not have POTS. Thirteen symptoms were analyzed. Symptoms that differed statistically between groups were further assessed for sensitivity, specificity, and diagnostic predictive values. Thirty-seven (53%) patients met diagnostic criteria for POTS. Several symptoms differed between the patients found to have POTS and those without POTS. Headache type was not predictive. Vertigo and evening exacerbation of headaches had P values <.05 but did not meet significance after a statistical correction for multiple variables, P ≤ .004 (0.05/13). New-onset motion sickness, dizziness as a headache trigger, and orthostatic headaches had P values <.004 and were relatively sensitive and/or specific for the POTS diagnosis. While no single clinical symptom or headache type reliably establishes the POTS diagnosis, several symptoms can help to distinguish the POTS patient in an adolescent headache population. © 2013 American Headache Society.

  15. Point-of-care-testing of standing posture with Wii balance board and Microsoft Kinect during transcranial direct current stimulation: a feasibility study.

    PubMed

    Dutta, Arindam; Chugh, Sanjay; Banerjee, Alakananda; Dutta, Anirban

    2014-01-01

    Non-invasive brain stimulation (NIBS) is a promising tool for facilitating motor function. NIBS therapy in conjunction with training using postural feedback may facilitate physical rehabilitation following posture disorders (e.g., Pusher Syndrome). The objectives of this study were, 1) to develop a low-cost point-of-care-testing (POCT) system for standing posture, 2) to investigate the effects of anodal tDCS on functional reach tasks using the POCT system. Ten community-dwelling elderly (age >50 years) subjects evaluated the POCT system for standing posture during functional reach tasks where their balance score on Berg Balance Scale was compared with that from Center-of-Mass (CoM) - Center-of-Pressure (CoP) posturography. Then, in a single-blind, sham-controlled study, five healthy right-leg dominant subjects (age: 26.4 ± 5.3 yrs) were evaluated using the POCT system under two conditions - with anodal tDCS of primary motor representations of right tibialis anterior muscle and with sham tDCS. The maximum CoP-CoM lean-angle was found to be well correlated with the BBS score in the elderly subjects The anodal tDCS strongly (p = 0.0000) affected the maximum CoP excursions but not the return reaction time in healthy. It was concluded that the CoM-CoP lean-line could be used for posture feedback and monitoring during tDCS therapy in conjunction with balance training exercises.

  16. Sequencing sit-to-stand and upright posture for mobility limitation assessment: determination of the timing of the task phases from force platform data.

    PubMed

    Mazzà, Claudia; Zok, Mounir; Della Croce, Ugo

    2005-06-01

    The identification of quantitative tools to assess an individual's mobility limitation is a complex and challenging task. Several motor tasks have been designated as potential indicators of mobility limitation. In this study, a multiple motor task obtained by sequencing sit-to-stand and upright posture was used. Algorithms based on data obtained exclusively from a single force platform were developed to detect the timing of the motor task phases (sit-to-stand, preparation to the upright posture and upright posture). To test these algorithms, an experimental protocol inducing predictable changes in the acquired signals was designed. Twenty-two young, able-bodied subjects performed the task in four different conditions: self-selected natural and high speed with feet kept together, and self-selected natural and high speed with feet pelvis-width apart. The proposed algorithms effectively detected the timing of the task phases, the duration of which was sensitive to the four different experimental conditions. As expected, the duration of the sit-to-stand was sensitive to the speed of the task and not to the foot position, while the duration of the preparation to the upright posture was sensitive to foot position but not to speed. In addition to providing a simple and effective description of the execution of the motor task, the correct timing of the studied multiple task could facilitate the accurate determination of variables descriptive of the single isolated phases, allowing for a more thorough description of the motor task and therefore could contribute to the development of effective quantitative functional evaluation tests.

  17. Reliability and concurrent validity of the Microsoft Xbox One Kinect for assessment of standing balance and postural control.

    PubMed

    Clark, Ross A; Pua, Yong-Hao; Oliveira, Cristino C; Bower, Kelly J; Thilarajah, Shamala; McGaw, Rebekah; Hasanki, Ksaniel; Mentiplay, Benjamin F

    2015-07-01

    The Microsoft Kinect V2 for Windows, also known as the Xbox One Kinect, includes new and potentially far improved depth and image sensors which may increase its accuracy for assessing postural control and balance. The aim of this study was to assess the concurrent validity and reliability of kinematic data recorded using a marker-based three dimensional motion analysis (3DMA) system and the Kinect V2 during a variety of static and dynamic balance assessments. Thirty healthy adults performed two sessions, separated by one week, consisting of static standing balance tests under different visual (eyes open vs. closed) and supportive (single limb vs. double limb) conditions, and dynamic balance tests consisting of forward and lateral reach and an assessment of limits of stability. Marker coordinate and joint angle data were concurrently recorded using the Kinect V2 skeletal tracking algorithm and the 3DMA system. Task-specific outcome measures from each system on Day 1 and 2 were compared. Concurrent validity of trunk angle data during the dynamic tasks and anterior-posterior range and path length in the static balance tasks was excellent (Pearson's r>0.75). In contrast, concurrent validity for medial-lateral range and path length was poor to modest for all trials except single leg eyes closed balance. Within device test-retest reliability was variable; however, the results were generally comparable between devices. In conclusion, the Kinect V2 has the potential to be used as a reliable and valid tool for the assessment of some aspects of balance performance.

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

    PubMed

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

    2016-09-01

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

  19. Role of the Frontal Cortex in Standing Postural Sway Tasks While Dual-Tasking: A Functional Near-Infrared Spectroscopy Study Examining Working Memory Capacity

    PubMed Central

    Fujita, Hiroyuki; Kasubuchi, Kenji; Wakata, Satoshi; Hiyamizu, Makoto; Morioka, Shu

    2016-01-01

    Posture control during a dual-task involves changing the distribution of attention resources between the cognitive and motor tasks and involves the frontal cortex working memory (WM). The present study aimed to better understand the impact of frontal lobe activity and WM capacity in postural control during a dual-task. High and low WM-span groups were compared using their reading span test scores. High and low WM capacity were compared based on cognitive and balance performance and hemoglobin oxygenation (oxyHb) levels during standing during single (S-S), standing during dual (S-D), one leg standing during single (O-S), and one leg standing during dual (O-D) tasks. For sway pass length, significant difference in only the O-D task was observed between both groups. oxyHb levels were markedly increased in the right dorsolateral prefrontal cortex and supplementary motor area in the high-span group during a dual-task. Therefore, WM capacity influenced the allocation of attentional resources and motor performance. PMID:27034947

  20. Effects of foot position of the nonparetic side during sit-to-stand training on postural balance in patients with stroke

    PubMed Central

    Han, Jintae; Kim, Youngmi; Kim, Kyung

    2015-01-01

    [Purpose] We aimed to investigate postural balance after sit-to-stand (STS) training with different nonparetic foot positions in stroke patients. [Subjects] Thirty-six subjects who experienced a stroke (21 males, 15 females) participated and were divided into the symmetric foot position (SYMM), asymmetric foot position (ASYM), and step foot (STEP) groups. [Methods] Each group performed repetitive sit-to-stand training 5 times a week for 6 weeks. The timed up-and-go test (TUG), functional reach test (FRT), and F-mat system correcting the anterior/posterior (A-P) and medial/lateral (M-L) distance of the center of pressure (COP) were used to measure the static and dynamic postural balance pre- and postintervention. ANCOVA was used to analyze differences among groups, and preintervention variables were used as covariates. [Results] The TUG, FRT, and A-P and M-L distance of the COP in the ASYM and STEP groups were significantly decreased after intervention compared with the SYMM group. All parameters in the STEP group were lower than those in the ASYM group, without a significant difference. [Conclusion] The asymmetric foot position during STS is a good intervention to improve the static and dynamic postural balance in stroke patients. Especially, using a step to change the foot position is effective in improving STS performance. PMID:26356809

  1. Effects of foot position of the nonparetic side during sit-to-stand training on postural balance in patients with stroke.

    PubMed

    Han, Jintae; Kim, Youngmi; Kim, Kyung

    2015-08-01

    [Purpose] We aimed to investigate postural balance after sit-to-stand (STS) training with different nonparetic foot positions in stroke patients. [Subjects] Thirty-six subjects who experienced a stroke (21 males, 15 females) participated and were divided into the symmetric foot position (SYMM), asymmetric foot position (ASYM), and step foot (STEP) groups. [Methods] Each group performed repetitive sit-to-stand training 5 times a week for 6 weeks. The timed up-and-go test (TUG), functional reach test (FRT), and F-mat system correcting the anterior/posterior (A-P) and medial/lateral (M-L) distance of the center of pressure (COP) were used to measure the static and dynamic postural balance pre- and postintervention. ANCOVA was used to analyze differences among groups, and preintervention variables were used as covariates. [Results] The TUG, FRT, and A-P and M-L distance of the COP in the ASYM and STEP groups were significantly decreased after intervention compared with the SYMM group. All parameters in the STEP group were lower than those in the ASYM group, without a significant difference. [Conclusion] The asymmetric foot position during STS is a good intervention to improve the static and dynamic postural balance in stroke patients. Especially, using a step to change the foot position is effective in improving STS performance.

  2. Standing postural instability in patients with schizophrenia: Relationships with psychiatric symptoms, anxiety, and the use of neuroleptic medications.

    PubMed

    Matsuura, Yukako; Fujino, Haruo; Hashimoto, Ryota; Yasuda, Yuka; Yamamori, Hidenaga; Ohi, Kazutaka; Takeda, Masatoshi; Imura, Osamu

    2015-03-01

    The purpose of this study was to assess postural instability in patients with schizophrenia using a pressure-sensitive platform and to examine the effects of anxiety, psychiatric symptoms, and the use of neuroleptic medications on postural sway. Participants were 23 patients with schizophrenia and 23 healthy controls. We found that the patients showed greater overall postural instability than the controls. Furthermore, they demonstrated greater instability when the test was performed with the eyes closed than with the eyes open. However, removal of visual input had less impact on the indices of postural instability in the patients than in the controls, suggesting that schizophrenia is associated with difficulties in integrating visual information and proprioceptive signals. Furthermore, in contrast to the controls, anxiety exacerbated postural instability in the patients. There were significant associations between postural stability and psychiatric symptoms in the patients without extrapyramidal symptoms, whereas medication dose did not significantly correlate with postural stability. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Effectiveness of audio-biofeedback in postural training for adolescent idiopathic scoliosis patients.

    PubMed

    Wong, M S; Mak, A F; Luk, K D; Evans, J H; Brown, B

    2001-04-01

    The possibility of using learned physiological responses in control of progressive adolescent idiopathic scoliosis (AIS) was investigated. Sixteen (16) AIS patients with progressing or high-risk curves (Cobb's angle between 25 degrees and 35 degrees at start and reducible by lateral bending) were fitted with a device with tone alarm for poor posture. In the first 18 months of application, 3 patients defaulted and 4 showed curve progression > 10 degrees (2 changed to rigid spinal orthoses and 2 underwent surgery). The curves for the other 9 patients were kept under control (within +/- 5 degrees of Cobb's angle) and 5 of them have reached skeletal maturity and terminated the application. The remaining 4 patients were still using the devices until skeletal maturity or curve progression. The curve control rate was 69%. A long-lasting active spinal control could be achieved through the patient's own spinal muscles. Nevertheless, before the postural training device could become a treatment modality, a long-term study for more AIS patients was necessary. This project is ongoing in the Duchess of Kent Children's Hospital, Sandy Bay, Hong Kong.

  4. The Complexity of Standing Postural Control in Older Adults: A Modified Detrended Fluctuation Analysis Based upon the Empirical Mode Decomposition Algorithm

    PubMed Central

    Liu, Dongdong; Hu, Kun; Zhang, Jue; Fang, Jing

    2013-01-01

    Human aging into senescence diminishes the capacity of the postural control system to adapt to the stressors of everyday life. Diminished adaptive capacity may be reflected by a loss of the fractal-like, multiscale complexity within the dynamics of standing postural sway (i.e., center-of-pressure, COP). We therefore studied the relationship between COP complexity and adaptive capacity in 22 older and 22 younger healthy adults. COP magnitude dynamics were assessed from raw data during quiet standing with eyes open and closed, and complexity was quantified with a new technique termed empirical mode decomposition embedded detrended fluctuation analysis (EMD-DFA). Adaptive capacity of the postural control system was assessed with the sharpened Romberg test. As compared to traditional DFA, EMD-DFA more accurately identified trends in COP data with intrinsic scales and produced short and long-term scaling exponents (i.e., αShort, αLong) with greater reliability. The fractal-like properties of COP fluctuations were time-scale dependent and highly complex (i.e., αShort values were close to one) over relatively short time scales. As compared to younger adults, older adults demonstrated lower short-term COP complexity (i.e., greater αShort values) in both visual conditions (p>0.001). Closing the eyes decreased short-term COP complexity, yet this decrease was greater in older compared to younger adults (p<0.001). In older adults, those with higher short-term COP complexity exhibited better adaptive capacity as quantified by Romberg test performance (r2 = 0.38, p<0.001). These results indicate that an age-related loss of COP complexity of magnitude series may reflect a clinically important reduction in postural control system functionality as a new biomarker. PMID:23650518

  5. The influence of vision and support base on balance during quiet standing in patients with adolescent idiopathic scoliosis before and after posterior spinal fusion.

    PubMed

    de Santiago, Hildemberg A R; Reis, Júlia G; Gomes, Matheus M; da Silva Herrero, Carlos F P; Defino, Helton L A; de Abreu, Daniela C C

    2013-11-01

    Scoliosis is the most common postural alteration in adolescence and is characterized by deviations of the spine in three planes. Surgical treatment based on arthrodesis has been developed, but the effects of such restructuring on the systems involved in postural control need to be better understood. To assess the influence of vision and the support base on balance in the quiet standing position in adolescents awaiting surgical treatment for idiopathic scoliosis. Longitudinal study/Ribeirão Preto Clinics Hospital (HC-FMRP-USP) and Laboratory of Assessment and Rehabilitation of Equilibrium at the FMRP-USP. Adolescent idiopathic scoliosis patients and controls. Center of pressure (CoP) sway area of the 95% confidence ellipse. Thirty female adolescents were divided into two groups according to their spinal alignment: control (n=15) and scoliosis groups (SGs) (n=15). The subjects with scoliosis were evaluated before and 7, 30, 60, and 90 days after surgery; the controls were evaluated once. The area of CoP oscillation was measured with the eyes open and closed and with two different support bases (feet apart or together). The force platform was purchased with funding support (US $8,375.00) provided by the Research Foundation of São Paulo (FAPESP). The study sponsors had no involvement in the study. Data were collected from the force platform and then statistically assessed through a linear model analysis of mixed effects. Data reveal that subjects in the SG oscillated more than controls, and postsurgery subjects had more oscillation than presurgery subjects. The results also indicated that both groups (control and scoliosis) showed more oscillation among those subjects with feet apart and eyes closed, but subjects with scoliosis were more affected by vision deprivation than by a reduced support base. Our results indicate that adolescents with idiopathic scoliosis are more dependent on visual information and that surgical correction does not change this relationship

  6. Differences in neurohumoral and hemodynamic response to prolonged head-up tilt between patients with high and normal standing norepinephrine forms of postural orthostatic tachycardia syndrome.

    PubMed

    Crnošija, Luka; Krbot Skorić, Magdalena; Lovrić, Mila; Junaković, Anamari; Miletić, Vladimir; Alfirev, Rujana Šprljan; Pavelić, Antun; Adamec, Ivan; Habek, Mario

    2017-07-01

    To investigate the optimal timing for blood sample collection of catecholamines and the possible correlations between neurohumoral and hemodynamic responses to prolonged head-up tilt (HUT) in postural orthostatic tachycardia syndrome (POTS). Nineteen patients underwent a 30-minute, 70° HUT test. Blood samples (norepinephrine (NE), epinephrine and dopamine) were taken in the 10th minute of supine, and 10th, 20th and 30th minutes of HUT. There were no significant differences in the proportion of high and normal standing NE patients in the different time points. Mean NE (nmol/L) values in 10th, 20th and 30th minute of HUT were 4.37, 4.87, and 4.35 in the high standing NE, and 2.49, 2.59 and 2.88 in the normal standing NE group. High standing NE patients had higher blood pressure (BP) during the first 6min of HUT (2nd minute after the HUT systolic BP (sBP): 118.29±15.65 vs. 95.70±13.43, p=0.004; diastolic BP (dBP): 78.71±6.68 vs. 65.10±9.04, p=0.003), while normal standing NE patients exhibited a drop in BP compared to resting values during the same time period. The normal standing NE group exhibited a progressive increase in norepinephrine values during the HUT. One blood sample taken at the 10th minute of HUT correctly identifies high and normal standing NE POTS patients, but a small number of patients (1 out of 19, 5.2%) can be misidentified. High and normal standing NE POTS patients display distinctly different neurohumoral and hemodynamic responses to HUT. Copyright © 2017. Published by Elsevier B.V.

  7. Longitudinal Associations of Electronic Aggression and Victimization with Social Standing during Adolescence

    ERIC Educational Resources Information Center

    Badaly, Daryaneh; Kelly, Brynn M.; Schwartz, David; Dabney-Lieras, Karen

    2013-01-01

    Prior empirical work has documented that the dynamics of social standing can play a critical role in the perpetration and receipt of aggression during adolescence. Recently, investigators have emphasized the emergence of new, electronic modalities for aggressive acts. Our longitudinal project therefore considered electronic forms of aggression and…

  8. Longitudinal Associations of Electronic Aggression and Victimization with Social Standing during Adolescence

    ERIC Educational Resources Information Center

    Badaly, Daryaneh; Kelly, Brynn M.; Schwartz, David; Dabney-Lieras, Karen

    2013-01-01

    Prior empirical work has documented that the dynamics of social standing can play a critical role in the perpetration and receipt of aggression during adolescence. Recently, investigators have emphasized the emergence of new, electronic modalities for aggressive acts. Our longitudinal project therefore considered electronic forms of aggression and…

  9. Postural balance in low back pain patients: Intra-session reliability of center of pressure on a portable force platform and of the one leg stand test.

    PubMed

    Maribo, Thomas; Stengaard-Pedersen, Kristian; Jensen, Lone Donbæk; Andersen, Niels Trolle; Schiøttz-Christensen, Berit

    2011-06-01

    Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (CoP) on a force platform. Portable force platforms might be of clinical relevance, but their reliability for LBP patients in a clinical setting has not been demonstrated. As LBP patients are more dependent on vision compared to healthy controls, the ratio of tests performed with eyes open and eyes closed (Romberg Ratio) might be of clinical interest. This study aimed to assess postural balance in LBP patients by analyzing intra-session reliability of CoP parameters on a portable force platform, the Romberg Ratio, and the OLST. Furthermore, we aimed to determine whether CoP parameters and OLST measure identical aspects of postural stability. We examined 49 LBP patients and found acceptable reliability of the CoP parameters' trace length and velocity, whereas reliability regarding C90 area, the Romberg Ratio, and the OLST was poor. Correlations between the CoP parameters and OLST were insignificant. Reliability of trace length and velocity is acceptable and can be used as parameters when assessing CoP in LBP patients. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Reliability and concurrent validity of postural asymmetry measurement in adolescent idiopathic scoliosis

    PubMed Central

    Prowse, Ashleigh; Aslaksen, Berit; Kierkegaard, Marie; Furness, James; Gerdhem, Paul; Abbott, Allan

    2017-01-01

    AIM To investigate the reliability and concurrent validity of the Baseline® Body Level/Scoliosis meter for adolescent idiopathic scoliosis postural assessment in three anatomical planes. METHODS This is an observational reliability and concurrent validity study of adolescent referrals to the Orthopaedic department for scoliosis screening at Karolinska University Hospital, Stockholm, Sweden between March-May 2012. A total of 31 adolescents with idiopathic scoliosis (13.6 ± 0.6 years old) of mild-moderate curvatures (25° ± 12°) were consecutively recruited. Measurement of cervical, thoracic and lumbar curvatures, pelvic and shoulder tilt, and axial thoracic rotation (ATR) were performed by two trained physiotherapists in one day. The intraclass correlation coefficient (ICC) was used to determine the inter-examiner reliability (ICC2,1) and the intra-rater reliability (ICC3,3) of the Baseline® Body Level/Scoliosis meter. Spearman’s correlation analyses were used to estimate concurrent validity between the Baseline® Body Level/Scoliosis meter and Gold Standard Cobb angles from radiographs and the Orthopaedic Systems Inc. Scoliometer. RESULTS There was excellent reliability between examiners for thoracic kyphosis (ICC2,1 = 0.94), ATR (ICC2,1 = 0.92) and lumbar lordosis (ICC2,1 = 0.79). There was adequate reliability between examiners for cervical lordosis (ICC2,1 = 0.51), however poor reliability for pelvic and shoulder tilt. Both devices were reproducible in the measurement of ATR when repeated by one examiner (ICC3,3 0.98-1.00). The device had a good correlation with the Scoliometer (rho = 0.78). When compared with Cobb angle from radiographs, there was a moderate correlation for ATR (rho = 0.627). CONCLUSION The Baseline® Body Level/Scoliosis meter provides reliable transverse and sagittal cervical, thoracic and lumbar measurements and valid transverse plan measurements of mild-moderate scoliosis deformity. PMID:28144582

  11. Reliability and concurrent validity of postural asymmetry measurement in adolescent idiopathic scoliosis.

    PubMed

    Prowse, Ashleigh; Aslaksen, Berit; Kierkegaard, Marie; Furness, James; Gerdhem, Paul; Abbott, Allan

    2017-01-18

    To investigate the reliability and concurrent validity of the Baseline(®) Body Level/Scoliosis meter for adolescent idiopathic scoliosis postural assessment in three anatomical planes. This is an observational reliability and concurrent validity study of adolescent referrals to the Orthopaedic department for scoliosis screening at Karolinska University Hospital, Stockholm, Sweden between March-May 2012. A total of 31 adolescents with idiopathic scoliosis (13.6 ± 0.6 years old) of mild-moderate curvatures (25° ± 12°) were consecutively recruited. Measurement of cervical, thoracic and lumbar curvatures, pelvic and shoulder tilt, and axial thoracic rotation (ATR) were performed by two trained physiotherapists in one day. The intraclass correlation coefficient (ICC) was used to determine the inter-examiner reliability (ICC2,1) and the intra-rater reliability (ICC3,3) of the Baseline(®) Body Level/Scoliosis meter. Spearman's correlation analyses were used to estimate concurrent validity between the Baseline(®) Body Level/Scoliosis meter and Gold Standard Cobb angles from radiographs and the Orthopaedic Systems Inc. Scoliometer. There was excellent reliability between examiners for thoracic kyphosis (ICC2,1 = 0.94), ATR (ICC2,1 = 0.92) and lumbar lordosis (ICC2,1 = 0.79). There was adequate reliability between examiners for cervical lordosis (ICC2,1 = 0.51), however poor reliability for pelvic and shoulder tilt. Both devices were reproducible in the measurement of ATR when repeated by one examiner (ICC3,3 0.98-1.00). The device had a good correlation with the Scoliometer (rho = 0.78). When compared with Cobb angle from radiographs, there was a moderate correlation for ATR (rho = 0.627). The Baseline(®) Body Level/Scoliosis meter provides reliable transverse and sagittal cervical, thoracic and lumbar measurements and valid transverse plan measurements of mild-moderate scoliosis deformity.

  12. Interaction between the oculomotor and postural systems during a dual-task: Compensatory reductions in head sway following visually-induced postural perturbations promote the production of accurate double-step saccades in standing human adults.

    PubMed

    Boulanger, Mathieu; Giraudet, Guillaume; Faubert, Jocelyn

    2017-01-01

    Humans routinely scan their environment for useful information using saccadic eye movements and/or coordinated movements of the eyes and other body segments such the head and the torso. Most previous eye movement studies were conducted with seated subject and showed that single saccades and sequences of saccades (e.g. double-step saccades) made to briefly flashed stimuli were equally accurate and precise. As one can easily appreciate, most gaze shifts performed daily by a given person are not produced from a seated position, but rather from a standing position either as subjects perform an action from an upright stance or as they walk from one place to another. In the experiments presented here, we developed a new dual-task paradigm in order to study the interaction between the gaze control system and the postural system. Healthy adults (n = 12) were required to both maintain balance and produce accurate single-step and double-step eye saccades from a standing position. Visually-induced changes in head sway were evoked using wide-field background stimuli that either moved in the mediolateral direction or in the anteroposterior direction. We found that, as in the seated condition, single- and double-step saccades were very precise and accurate when made from a standing position, but that a tighter control of head sway was necessary in the more complex double-step saccades condition for equivalent results to be obtained. Our perturbation results support the "common goal" hypothesis that state that if necessary, as was the case during the more complex oculomotor task, context-dependent modulations of the postural system can be triggered to reduced instability and therefore support the accomplishment of a suprapostural goal.

  13. Interaction between the oculomotor and postural systems during a dual-task: Compensatory reductions in head sway following visually-induced postural perturbations promote the production of accurate double-step saccades in standing human adults

    PubMed Central

    Giraudet, Guillaume; Faubert, Jocelyn

    2017-01-01

    Humans routinely scan their environment for useful information using saccadic eye movements and/or coordinated movements of the eyes and other body segments such the head and the torso. Most previous eye movement studies were conducted with seated subject and showed that single saccades and sequences of saccades (e.g. double-step saccades) made to briefly flashed stimuli were equally accurate and precise. As one can easily appreciate, most gaze shifts performed daily by a given person are not produced from a seated position, but rather from a standing position either as subjects perform an action from an upright stance or as they walk from one place to another. In the experiments presented here, we developed a new dual-task paradigm in order to study the interaction between the gaze control system and the postural system. Healthy adults (n = 12) were required to both maintain balance and produce accurate single-step and double-step eye saccades from a standing position. Visually-induced changes in head sway were evoked using wide-field background stimuli that either moved in the mediolateral direction or in the anteroposterior direction. We found that, as in the seated condition, single- and double-step saccades were very precise and accurate when made from a standing position, but that a tighter control of head sway was necessary in the more complex double-step saccades condition for equivalent results to be obtained. Our perturbation results support the “common goal” hypothesis that state that if necessary, as was the case during the more complex oculomotor task, context-dependent modulations of the postural system can be triggered to reduced instability and therefore support the accomplishment of a suprapostural goal. PMID:28296958

  14. Early adolescents' social standing in peer groups: behavioral correlates of stability and change.

    PubMed

    Lansford, Jennifer E; Killeya-Jones, Ley A; Miller, Shari; Costanzo, Philip R

    2009-09-01

    Sociometric nominations, social cognitive maps, and self-report questionnaires were completed in consecutive years by 327 students (56% girls) followed longitudinally from grade 7 to grade 8 to examine the stability of social standing in peer groups and correlates of changes in social standing. Social preference, perceived popularity, network centrality, and leadership were moderately stable from grade 7 to grade 8. Alcohol use and relational aggression in grade 7 predicted changes in social preference and centrality, respectively, between grade 7 and grade 8, but these effects were moderated by gender and ethnicity. Changes in social standing from grade 7 to grade 8 were unrelated to grade 8 physical aggression, relational aggression, and alcohol use after controlling for the grade 7 corollaries of these behaviors. Results are discussed in terms of their implications for understanding links between social standing and problem behaviors during adolescence.

  15. The influence of seat heights and foot placement positions on postural control in children with cerebral palsy during a sit-to-stand task.

    PubMed

    Medeiros, Daiane Lazzeri de; Conceição, Josilene Souza; Graciosa, Maylli Daiani; Koch, Deyse Borges; Santos, Marcio Jose Dos; Ries, Lilian Gerdi Kittel

    2015-01-01

    This paper aimed to analyze, from both a kinetic and kinematic perspective, the postural control of children with cerebral palsy (CP) able to independently perform the sit-to-stand (STS) task (ICP) and children who needed support (SCP) typically developing children during the STS; and also investigate the influence of seats heights and foot placement positions on postural control of these children. Fourteen children with CP and fourteen typically developing controls were recruited. Based on the Gross Motor Function Classification System (GMFCS) the children with CP were divided into ICP (level I) and SCP (levels II and III). Balance was assessed using the Pediatric Balance Scale. Motor function was rated using the GMFCS. Kinematic and kinetic data were recorded and analyzed during the STS task at two different seat heights and foot placement positions. The SCP exhibited significantly less balance according to the PBS and smaller displacement of their center of pressure (COP) in anteroposterior (COPAP) and mediolateral (COPML) direction relative to the other two groups. ICP demonstrated significant greater in the COPML displacement than the other groups. Children with CP required more time to complete the STS than controls. Those in the SCP group had lower linear displacement of the shoulder and knee than others during the STS task. During the high bench condition, the linear displacements of the shoulder and knee were reduced also. We conclude that the SCP has less COPAP and COPML oscillation, what means the better postural control during STS than the other two groups, which may be related to the support provided. The ICP exhibited greater COPML oscillations than controls, suggesting that they utilized different strategies in the frontal plane during the STS task. The seat height and foot placement did not influence postural control in children with CP, at least in terms of kinetic parameters. Seat height influenced the kinematic variables, with a high bench

  16. Effect of standing posture during whole body vibration training on muscle morphology and function in older adults: A randomised controlled trial

    PubMed Central

    2010-01-01

    Background Whole body vibration (WBV) is a novel modality of exercise shown to improve musculoskeletal function. This study aims to examine the effects of standing posture during low magnitude WBV training on muscle function and muscle morphology in older adults. Methods Nineteen men and women (50-80 years) were recruited to a three month randomised controlled trial and allocated to one of three groups: WBV with flexed knees (FK), WBV with locked knees (LK), or sham WBV with flexed knees (CON). Exposure was intermittent (1 min WBV:1 min rest) for 20 min, three times per week for 13 weeks. Measurements were taken at baseline and at three months. Primary outcomes included upper and lower body muscle function (strength, power and velocity). Secondary outcomes were muscle morphology, balance, habitual and maximal gait velocity, stair climb power, and chair stand performance. Results Sixteen subjects completed the study. Relative (%) upper body contraction velocity improved significantly after WBV with FK compared to LK (FK 16.0%, LK -7.6%, CON 4.7, p = 0.01). Relative upper body strength (LK 15.1%, p = 0.02; FK 12.1%, p = 0.04; CON 4.7%) increased significantly following WBV compared to control. Absolute (p = 0.05) and relative (p = 0.03) lower leg strength significantly improved with both standing postures (LK 14.4%; FK 10.7%; CON 1.3%). Only the LK group differed significantly from CON in relative leg strength gains (p = 0.02). Potentially clinically meaningful but statistically non-significant improvements in lower leg muscle cross-sectional area (LK 3.7 cm2, FK 2.4 cm2, CON 2.2 cm2 p = 0.13) were observed after WBV with LK compared to the other groups. No significant effects of WBV on any functional performance tests were observed. Conclusions Our results suggest that WBV may improve muscle strength and contraction velocity in some muscle groups in older adults. However, hypothesised differential adaptation to standing posture (FK > LK) was observed only for upper

  17. Assessment of diffusion tensor imaging indices in calf muscles following postural change from standing to supine position.

    PubMed

    Elzibak, Alyaa H; Noseworthy, Michael D

    2014-10-01

    To investigate whether postural change from erect to recumbent position affects calf muscle water diffusivity. Ten healthy adults (27.2 ± 4.9 years, 3 females) were imaged at baseline (following assumption of recumbent position), and after 34 min (session 2) and 64 min (session 3) of laying supine within a 3T MRI scanner. Diffusion tensor imaging (DTI) eigenvalues, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were evaluated in five calf muscles (anterior and posterior tibialis and triceps surae) during each of the three imaging sessions. Significant decreases were observed in all of the eigenvalues and ADC in each of the muscles with postural change. These reductions ranged from 3.2 to 6.7% and 3.4 to 7.5% for the various DTI metrics, following 34 and 64 min of supine rest, respectively (P < 0.05). No significant differences were noted in ADC or eigenvalues between the second and third imaging sessions for any muscle. FA did not change significantly with postural manipulation in any muscle compartment. Diffusion tensor imaging indices were altered with postural change. As differences were not apparent between the latter two imaging sessions, we suggest that a short supine resting period (~34 min) is sufficient for muscle diffusivity to stabilize prior to quantitative MR imaging in healthy young adults.

  18. Adolescents with Intellectual Disability Have Reduced Postural Balance and Muscle Performance in Trunk and Lower Limbs Compared to Peers without Intellectual Disability

    ERIC Educational Resources Information Center

    Blomqvist, Sven; Olsson, Josefine; Wallin, Louise; Wester, Anita; Rehn, Borje

    2013-01-01

    For adolescent people with ID, falls are more common compared to peers without ID. However, postural balance among this group is not thoroughly investigated. The aim of this study was to compare balance and muscle performance among adolescents aged between 16 and 20 years with a mild to moderate intellectual disability (ID) to age-matched…

  19. Adolescents with Intellectual Disability Have Reduced Postural Balance and Muscle Performance in Trunk and Lower Limbs Compared to Peers without Intellectual Disability

    ERIC Educational Resources Information Center

    Blomqvist, Sven; Olsson, Josefine; Wallin, Louise; Wester, Anita; Rehn, Borje

    2013-01-01

    For adolescent people with ID, falls are more common compared to peers without ID. However, postural balance among this group is not thoroughly investigated. The aim of this study was to compare balance and muscle performance among adolescents aged between 16 and 20 years with a mild to moderate intellectual disability (ID) to age-matched…

  20. Lumbar spine and pelvic posture between standing and sitting: a radiologic investigation including reliability and repeatability of the lumbar lordosis measure.

    PubMed

    De Carvalho, Diana E; Soave, David; Ross, Kim; Callaghan, Jack P

    2010-01-01

    Sitting has been identified as a cause of mechanical low back pain. The purpose of this study was to use plain film x-rays to measure lumbar spine and pelvic posture differences between standing and sitting. Eight male subjects were radiographed standing and sitting in an automobile seat. Measures of lumbar lordosis, intervertebral disk angles, lumbosacral angle, lumbosacral lordosis, and sacral tilt were completed. One-way analysis of variance (alpha = .05) was conducted on the variables stated above. A Bland-Altman analysis was conducted to assess agreement and repeatability of the lumbar lordosis angle using 2 raters. Lumbar lordosis values in standing (average, 63 degrees +/- 15 degrees ) and sacral inclination (average, 43 degrees +/- 10 degrees ) decreased by 43 degrees and 44 degrees , respectively, in sitting. Intervertebral joint angles in sitting underwent substantial flexion (L1/L2-5 degrees [+/-3 degrees ], L2/L3-7 degrees [+/-3 degrees ], L3/L4-8 degrees [+/-3 degrees ], L4/L5-13 degrees [+/-3 degrees ], and L5/S1-4 degrees [+/-10 degrees ]). Measures of lumbar lordosis; intervertebral disk angles between L2/L3, L3/L4, and L4/L5; lumbosacral lordosis; lumbosacral angle; and sacral tilt were significantly decreased between standing and sitting (P < .001). Intervertebral disk angle between L5/S1 was not significantly different. Analysis using the Bland-Altman technique found good agreement and stable repeatability of measures with no statistical significant differences between or within raters (R1, P = .8474; R2, P = .4402; and R-R2, P = .8691). The significant differences in lumbar and pelvic measures from standing to sitting further emphasize the range of motion experienced at vertebral levels in sitting. Based on the results of this study, interventions to return motion segments to a less flexed posture should be investigated because they may play a role in preventing injury and low back pain. Copyright 2010 National University of Health Sciences

  1. Postural Control Characteristics during Single Leg Standing of Individuals with a History of Ankle Sprain: Measurements Obtained Using a Gravicorder and Head and Foot Accelerometry.

    PubMed

    Abe, Yota; Sugaya, Tomoaki; Sakamoto, Masaaki

    2014-03-01

    [Purpose] This study aimed to validate the postural control characteristics of individuals with a history of ankle sprain during single leg standing by using a gravicorder and head and foot accelerometry. [Subjects] Twenty subjects with and 23 subjects without a history of ankle sprain (sprain and control groups, respectively) participated. [Methods] The anteroposterior, mediolateral, and total path lengths, as well as root mean square (RMS) of each length, were calculated using the gravicorder. The anteroposterior, mediolateral, and resultant acceleration of the head and foot were measured using accelerometers and were evaluated as the ratio of the acceleration of the head to the foot. [Results] There was no significant difference between the two groups in path length or RMS acceleration of the head and foot. However, the ratios of the mediolateral and resultant components were significantly higher in the sprain group than in the control group. [Conclusion] Our findings suggest that individuals with a history of ankle sprain have a higher head-to-foot acceleration ratio and different postural control characteristics than those of control subjects.

  2. Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb.

    PubMed

    Jones, Gareth D; James, Darren C; Thacker, Michael; Green, David A

    2016-08-30

    Individuals with sensorimotor pathology e.g., stroke have difficulty executing the common task of rising from sitting and initiating gait (sit-to-walk: STW). Thus, in clinical rehabilitation separation of sit-to-stand and gait initiation - termed sit-to-stand-and-walk (STSW) - is usual. However, a standardized STSW protocol with a clearly defined analytical approach suitable for pathological assessment has yet to be defined. Hence, a goal-orientated protocol is defined that is suitable for healthy and compromised individuals by requiring the rising phase to be initiated from 120% knee height with a wide base of support independent of lead limb. Optical capture of three-dimensional (3D) segmental movement trajectories, and force platforms to yield two-dimensional (2D) center-of-pressure (COP) trajectories permit tracking of the horizontal distance between COP and whole-body-center-of-mass (BCOM), the decrease of which increases positional stability but is proposed to represent poor dynamic postural control. BCOM-COP distance is expressed with and without normalization to subjects' leg length. Whilst COP-BCOM distances vary through STSW, normalized data at the key movement events of seat-off and initial toe-off (TO1) during steps 1 and 2 have low intra and inter subject variability in 5 repeated trials performed by 10 young healthy individuals. Thus, comparing COP-BCOM distance at key events during performance of an STSW paradigm between patients with upper motor neuron injury, or other compromised patient groups, and normative data in young healthy individuals is a novel methodology for evaluation of dynamic postural stability.

  3. Comparison of conversion coefficients for equivalent dose in terms of air kerma for photons using a male adult voxel simulator in sitting and standing posture with geometry of irradiation antero-posterior

    NASA Astrophysics Data System (ADS)

    Galeano, D. C.; Cavalcante, F. R.; Carvalho, A. B.; Hunt, J.

    2014-02-01

    The dose conversion coefficient (DCC) is important to quantify and assess effective doses associated with medical, professional and public exposures. The calculation of DCCs using anthropomorphic simulators and radiation transport codes is justified since in-vivo measurement of effective dose is extremely difficult and not practical for occupational dosimetry. DCCs have been published by the ICRP using simulators in a standing posture, which is not always applicable to all exposure scenarios, providing an inaccurate dose estimation. The aim of this work was to calculate DCCs for equivalent dose in terms of air kerma (H/Kair) using the Visual Monte Carlo (VMC) code and the VOXTISS8 adult male voxel simulator in sitting and standing postures. In both postures, the simulator was irradiated by a plane source of monoenergetic photons in antero-posterior (AP) geometry. The photon energy ranged from 15 keV to 2 MeV. The DCCs for both postures were compared and the DCCs for the standing simulator were higher. For certain organs, the difference of DCCs were more significant, as in gonads (48% higher), bladder (16% higher) and colon (11% higher). As these organs are positioned in the abdominal region, the posture of the anthropomorphic simulator modifies the form in which the radiation is transported and how the energy is deposited. It was also noted that the average percentage difference of conversion coefficients was 33% for the bone marrow, 11% for the skin, 13% for the bone surface and 31% for the muscle. For other organs, the percentage difference of the DCCs for both postures was not relevant (less than 5%) due to no anatomical changes in the organs of the head, chest and upper abdomen. We can conclude that is important to obtain DCCs using different postures from those present in the scientific literature.

  4. Effect of a spinal brace on postural control in different sensory conditions in adolescent idiopathic scoliosis: a preliminary analysis.

    PubMed

    Gur, Gozde; Dilek, Burcu; Ayhan, Cigdem; Simsek, Engin; Aras, Ozgen; Aksoy, Songul; Yakut, Yavuz

    2015-01-01

    Despite the positive effects of spinal braces on postural stability, they may constrain movement, resulting in poor balance control in patients with adolescent idiopathic scoliosis (AIS). Therefore, assessment of postural dynamics may aid in designing new less-constraining braces. The effects of a spinal brace on postural stability and Cobb angle were investigated in this study. Thirteen pediatric patients (10 females, three males) with AIS were recruited to participate in the study. Cobb angle was assessed by X-ray analyses, and postural stability was tested by computerized dynamic posturography in braced and unbraced conditions. A polyethylene underarm corrective spinal brace was fabricated for the subjects. Thoracic and lumbar curvature decreased to 18.88 ± 11.73° and 17.70 ± 10.58°, respectively, after bracing (p < 0.05). Lower equilibrium scores were observed in the "eyes closed" condition and higher scores in the "eyes closed with a swaying support" condition; higher composite equilibrium scores were also observed for the sensory organization test (p < 0.05) in the braced condition. Lower scores were observed for the "toes-up adaptation test" in the braced condition (p < 0.05). In the braced condition, the reaction time was slower in the right-backward direction and movement velocity was higher in the right-front direction on the limits of stability test (p < 0.05). Furthermore, lower on-axis velocity during forward/backward dynamic balance control was observed in the braced condition (p < 0.05). Wearing a spinal brace improved postural stability in terms of increased proprioception, equilibrium performance, and rhythmic movement ability in patients with AIS. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Smart garment to help children improve posture.

    PubMed

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

    2006-01-01

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

  6. The effects of training and detraining after an 8 month resistance and stretching training program on forward head and protracted shoulder postures in adolescents: Randomised controlled study.

    PubMed

    Ruivo, R M; Carita, A I; Pezarat-Correia, P

    2016-02-01

    This study aimed to evaluate the effects of a 32-week resistance and stretching training program applied in Physical Education classes on forward head posture and protracted shoulder posture of Portuguese adolescents (15-17 years old). The detraining effects after a 16-week period were also measured. This prospective, randomized and controlled study was conducted in two secondary schools in Portugal. One hundred and thirty adolescents with forward head and protracted shoulder posture were randomly assigned to a control or experimental group. The sagittal head, cervical and shoulder angle were measured before and after a 32-week time intervention period. The control group (n = 46) did only the Physical Education classes whereas the exercise group (n = 42) received a posture corrective exercise programme in addition to Physical Education classes. A 16 week detraining period followed the 32-week. Significant increase were observed in the cervical and shoulder angle in the experimental group following the 32 week-intervention period. After the 16-week detraining period no significant differences were observed in the three postural angles in the intervention group. The exercise intervention was successful at decreasing forward head and protracted shoulder in adolescents. Detraining period was not sufficient to reduce the overall training effects. This study supports the postural training and rehabilitation performed during Physical Education classes, with the aim of preventing and managing upper quadrant musculoskeletal pain. CLINICALTRIALS. NCT02190331. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    PubMed Central

    Shiozawa, Shinichiro; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

    2015-01-01

    Background Postural control during rapid movements may be impaired due to musculoskeletal pain. The purpose of this study was to investigate the effect of experimental knee-related muscle pain on the center of pressure (CoP) displacement in a reaction time task condition. Methods Nine healthy males performed two reaction time tasks (dominant side shoulder flexion and bilateral heel lift) before, during, and after experimental pain induced in the dominant side vastus medialis or the tibialis anterior muscles by hypertonic saline injections. The CoP displacement was extracted from the ipsilateral and contralateral side by two force plates and the net CoP displacement was calculated. Results Compared with non-painful sessions, tibialis anterior muscle pain during the peak and peak-to-peak displacement for the CoP during anticipatory postural adjustments (APAs) of the shoulder task reduced the peak-to-peak displacement of the net CoP in the medial-lateral direction (P<0.05). Tibialis anterior and vastus medialis muscle pain during shoulder flexion task reduced the anterior-posterior peak-to-peak displacement in the ipsilateral side (P<0.05). Conclusions The central nervous system in healthy individuals was sufficiently robust in maintaining the APA characteristics during pain, although the displacement of net and ipsilateral CoP in the medial-lateral and anterior-posterior directions during unilateral fast shoulder movement was altered. PMID:26680777

  8. Does a prototype 'Experimental' chair facilitate more postural changes in computing adolescents compared to a normal school chair?

    PubMed

    van Niekerk, Sjan-Mari; Louw, Quinette Abegail; Grimmer, Karen

    2016-09-27

    Prolonged sitting, such as when computing, has been linked to adolescent spinal pain. A chair should fit the user's body dimensions and aid the user in frequently changing sitting posture, rather than support one 'ideal' posture. Such a chair is not currently available to high school learners. To develop a novel experimental school chair. To determine whether the experimental chair encourages regular small range movement in all directions whilst students work at computers in class. To compare the number of postural changes between the normal static school chair and the experimental chair, whilst students do computing work. A development and validation study was conducted. Twelve high school students were randomly selected from a conveniently selected school. Fifteen minutes of 3D posture measurements were collected in both the prototype and school computer chair. The analysis focused on the frequency of postural movement. Data of eleven learners were analysed. There were statistically significant increases in the number of postural changes on the 'Experimental' chair compared to the school chair, for both pelvic side-flexion and pelvic rotation (ρ= 0.01). The experimental chair provided more postural movements when compared to the school computer chair. Future studies should use this experimental chair to determine the effect of increased postural movement, of especially the pelvis, on the prevalence and intensity of musculoskeletal symptoms of high school learners in the Cape Metropole area, Western Cape, South Africa.

  9. Reduced postural differences between phobic postural vertigo patients and healthy subjects during a postural threat.

    PubMed

    Holmberg, Johan; Tjernström, Fredrik; Karlberg, Mikael; Fransson, Per Anders; Magnusson, Måns

    2009-08-01

    Phobic postural vertigo is characterized by subjective imbalance and dizziness while standing or walking, despite normal values for clinical balance tests. Patients with phobic postural vertigo exhibit an increased high-frequency sway in posturographic tests. Their postural sway, however, becomes similar to the sway of healthy subjects during difficult balance tasks. Posturographic recordings of 30 s of quiet stance was compared to recordings of 30 s of quiet stance during a postural threat, which consisted of the knowledge of forthcoming vibratory calf muscle stimulation, in 37 consecutive patients with phobic postural vertigo and 24 healthy subjects. During quiet stance without the threat of forthcoming vibratory stimulation, patients with phobic postural vertigo exhibited a postural sway containing significantly more high-frequency sway than the healthy subjects. During the quiet stance with forthcoming vibratory stimulation, i.e., anticipation of a postural threat, the significant differences between groups disappeared for all variables except sagittal high-frequency sway. During postural threat, healthy subjects seemed to adopt a postural strategy that was similar to that exhibited by phobic postural vertigo patients. The lack of additional effects facing a postural threat among phobic postural vertigo patients may be due to an already maximized postural adaptation. Deviant postural reactions among patients with phobic postural vertigo may be considered as an avoidant postural response due to a constant fear of losing postural control.

  10. Pilates improves lower limbs strength and postural control during quite standing in a child with hemiparetic cerebral palsy: A case report study.

    PubMed

    Dos Santos, Adriana Neves; Serikawa, Simoni Sayuri; Rocha, Nelci Adriana Cicuto Ferreira

    2016-08-01

    To verify the effect of Pilates exercises in a child with cerebral palsy (CP) with mild functional impairment. We evaluated average peak torque of ankle and knee extensors/flexors using a Biodex System, using concentric active-assisted test. We also evaluated amplitude of anterior-posterior and of medial-lateral displacement of the CoP and area of oscillation during quite standing with a BERTEC platform. We applied Pilates exercises for eight weeks. Peak torque/body weight of ankle and knee extensors/flexors of both affected and unaffected limbs increased after Pilates. Also, all kinetic variables decreased after Pilates' intervention. After one-month follow-up, isokinetic variable values were higher while kinetic variable values were lower than baseline values. Pilates may be an important rehabilitation technique for children with CP that present mild deficits in motor structures and high functional level, especially when the aims are to improve muscle strength and postural control during quite standing.

  11. The functional role of sensory inputs from the foot: stabilizing human standing posture during voluntary and vibration-induced body sway.

    PubMed

    Hayashi, R; Miyake, A; Watanabe, S

    1988-02-01

    The functional role of sensory inputs from the foot in the stabilization of upright standing in humans was studied using an ischemic nerve block which was applied bilaterally at the level of the ankle. Subjects were asked: (1) to lean forward or backward by pivoting around their ankle joints; and (2) to hold a standing posture during the bilateral application of vibration (140 Hz) to the Achilles tendons. After 30-40 min of ischemia, the magnitude of maximum body leaning was equally reduced to about 70% of controls for both the "eyes-open" and "eyes-closed" conditions with bare feet. This decrease of body leaning caused by ischemia was not observed when a foot was fixed firmly on a "fixation" board. During vibration, body sway was augmented, and characteristic oscillations of this body sway around 3 Hz were observed under ischemic conditions with eyes closed and with bare feet. We concluded that foot sensation may be an important source of information for controlling the magnitude of body leaning and for stabilizing higher frequency components of body sway.

  12. The spinal posture of computing adolescents in a real-life setting

    PubMed Central

    2014-01-01

    Background It is assumed that good postural alignment is associated with the less likelihood of musculoskeletal pain symptoms. Encouraging good sitting postures have not reported consequent musculoskeletal pain reduction in school-based populations, possibly due to a lack of clear understanding of good posture. Therefore this paper describes the variability of postural angles in a cohort of asymptomatic high-school students whilst working on desk-top computers in a school computer classroom and to report on the relationship between the postural angles and age, gender, height, weight and computer use. Methods The baseline data from a 12 month longitudinal study is reported. The study was conducted in South African school computer classrooms. 194 Grade 10 high-school students, from randomly selected high-schools, aged 15–17 years, enrolled in Computer Application Technology for the first time, asymptomatic during the preceding month, and from whom written informed consent were obtained, participated in the study. The 3D Posture Analysis Tool captured five postural angles (head flexion, neck flexion, cranio-cervical angle, trunk flexion and head lateral bend) while the students were working on desk-top computers. Height, weight and computer use were also measured. Individual and combinations of postural angles were analysed. Results 944 Students were screened for eligibility of which the data of 194 students are reported. Trunk flexion was the most variable angle. Increased neck flexion and the combination of increased head flexion, neck flexion and trunk flexion were significantly associated with increased weight and BMI (p = 0.0001). Conclusions High-school students sit with greater ranges of trunk flexion (leaning forward or reclining) when using the classroom computer. Increased weight is significantly associated with increased sagittal plane postural angles. PMID:24950887

  13. The spinal posture of computing adolescents in a real-life setting.

    PubMed

    Brink, Yolandi; Louw, Quinette; Grimmer, Karen; Jordaan, Esmè

    2014-06-20

    It is assumed that good postural alignment is associated with the less likelihood of musculoskeletal pain symptoms. Encouraging good sitting postures have not reported consequent musculoskeletal pain reduction in school-based populations, possibly due to a lack of clear understanding of good posture. Therefore this paper describes the variability of postural angles in a cohort of asymptomatic high-school students whilst working on desk-top computers in a school computer classroom and to report on the relationship between the postural angles and age, gender, height, weight and computer use. The baseline data from a 12 month longitudinal study is reported. The study was conducted in South African school computer classrooms. 194 Grade 10 high-school students, from randomly selected high-schools, aged 15-17 years, enrolled in Computer Application Technology for the first time, asymptomatic during the preceding month, and from whom written informed consent were obtained, participated in the study. The 3D Posture Analysis Tool captured five postural angles (head flexion, neck flexion, cranio-cervical angle, trunk flexion and head lateral bend) while the students were working on desk-top computers. Height, weight and computer use were also measured. Individual and combinations of postural angles were analysed. 944 Students were screened for eligibility of which the data of 194 students are reported. Trunk flexion was the most variable angle. Increased neck flexion and the combination of increased head flexion, neck flexion and trunk flexion were significantly associated with increased weight and BMI (p = 0.0001). High-school students sit with greater ranges of trunk flexion (leaning forward or reclining) when using the classroom computer. Increased weight is significantly associated with increased sagittal plane postural angles.

  14. Electromyographic responses of erector spinae and lower limb's muscles to dynamic postural perturbations in patients with adolescent idiopathic scoliosis.

    PubMed

    Farahpour, Nader; Ghasemi, Safoura; Allard, Paul; Saba, Mohammad Sadegh

    2014-10-01

    The aim of this study was to evaluate electromyographic (EMG) responses of erector spinae (ES) and lower limbs' muscles to dynamic forward postural perturbation (FPP) and backward postural perturbation (BPP) in patients with adolescent idiopathic scoliosis (AIS) and in a healthy control group. Ten right thoracic AIS patients (Cobb=21.6±4.4°) and 10 control adolescents were studied. Using bipolar surface electrodes, EMG activities of ES muscle at T10 (EST10) and L3 (ESL3) levels, biceps femoris (BF), gastrocnemius lateralis (G) and rectus femoris (RF) muscles in the right and the left sides during FPP and BPP were evaluated. Muscle responses were measured over a 1s time window after the onset of perturbation. In FPP test, the EMG responses of right EST10, ESL3 and BF muscles in the scoliosis group were respectively about 1.40 (p=0.035), 1.43 (p=0.07) and 1.45 (p=0.01) times greater than those in control group. Also, in BPP test, at right ESL3 muscle of the scoliosis group the EMG activity was 1.64 times higher than that in the control group (p=0.01). The scoliosis group during FPP displayed asymmetrical muscle responses in EST10 and BF muscles. This asymmetrical muscle activity in response to FPP is hypothesized to be a possible compensatory strategy rather than an inherent characteristic of scoliosis.

  15. Identification and experimental validation of damping ratios of different human body segments through anthropometric vibratory model in standing posture.

    PubMed

    Gupta, T C

    2007-08-01

    A 15 degrees of freedom lumped parameter vibratory model of human body is developed, for vertical mode vibrations, using anthropometric data of the 50th percentile US male. The mass and stiffness of various segments are determined from the elastic modulii of bones and tissues and from the anthropometric data available, assuming the shape of all the segments is ellipsoidal. The damping ratio of each segment is estimated on the basis of the physical structure of the body in a particular posture. Damping constants of various segments are calculated from these damping ratios. The human body is modeled as a linear spring-mass-damper system. The optimal values of the damping ratios of the body segments are estimated, for the 15 degrees of freedom model of the 50th percentile US male, by comparing the response of the model with the experimental response. Formulating a similar vibratory model of the 50th percentile Indian male and comparing the frequency response of the model with the experimental response of the same group of subjects validate the modeling procedure. A range of damping ratios has been considered to develop a vibratory model, which can predict the vertical harmonic response of the human body.

  16. Exercises for the torso performed in a standing posture: spine and hip motion and motor patterns and spine load.

    PubMed

    McGill, Stuart M; Karpowicz, Amy; Fenwick, Chad M J; Brown, Stephen H M

    2009-03-01

    The purpose of this study was to document the muscle activity, spine motion, spine load, and stiffness during several movement-based or "functional" exercises and to assess the effect of technique change. Eight subjects, all healthy men from a university population, were instrumented to obtain surface electromyography of selected trunk and hip muscles, together with video analysis and electromagnetic lumbar spine position sensor to track spine posture. Exercises included a walkout in the sagittal plane that compared an upright form against a wall with those performed on the floor, overhead cable pushes, lateral cable walkouts, the good morning exercise, and the bowler's squat. Generally, muscle activation levels were quite modest even though the tasks were quite strenuous in many cases. Even though similar joint moments were required in different exercises, the pattern of activity between muscles was different. Abdominal bracing increased spine stiffness at the expense of more spine load. Thus, muscle activity seems to be constrained in "functional" exercises. There are several possible reasons for this. Single muscles cannot be activated to 100% of the maximum voluntary contraction in functional exercises because this would upset the balance of moments about the 3 orthopedic axes of the spine, or it would upset the balance of stiffening muscles around the spine required to ensure stability of the spinal column. The one exception was the floor walkout, which resulted in full activation of the rectus abdominis; however, this was a sagittal plane task without the joint moment constraints of multiplanar exercise. Therefore, maximal muscle activity is observed during single-plane tasks, but muscle activation levels were constrained during functional tasks. Thus, strength training muscles may not help in "functional multiplanar" tasks. These data can be used to assist decisions regarding the selection of exercises, specifically choices regarding the starting challenge

  17. Standing footprint diagnostic method

    NASA Astrophysics Data System (ADS)

    Fan, Y. F.; Fan, Y. B.; Li, Z. Y.; Newman, T.; Lv, C. S.; Fan, Y. Z.

    2013-10-01

    Center of pressure is commonly used to evaluate standing balance. Even though it is incomplete, no better evaluation method has been presented. We designed our experiment with three standing postures: standing with feet together, standing with feet shoulder width apart, and standing with feet slightly wider than shoulder width. Our platform-based pressure system collected the instantaneous plantar pressure (standing footprint). A physical quantity of instantaneous standing footprint principal axis was defined, and it was used to construct an index to evaluate standing balance. Comparison between results from our newly established index and those from the center of pressure index to evaluate the stability of different standing postures revealed that the standing footprint principal axis index could better respond to the standing posture change than the existing one. Analysis indicated that the insensitive response to the relative position between feet and to the standing posture change from the center of pressure could be better detected by the standing footprint principal axis index. This predicts a wide application of standing footprint principal axis index when evaluating standing balance.

  18. The Effect of Somatosensory and Cognitive-motor Tasks on the Paretic Leg of Chronic Stroke Patients in the Standing Posture

    PubMed Central

    Ju, Sung-kwang; Yoo, Won-gyu

    2014-01-01

    [Purpose] The purpose of this study was to investigate how different standing surfaces alter somatosensory input and how postural control is affected by these changes during the performance of a dual task with a cognitive-motor aspect. [Subjects] The subjects were 20 chronic stroke patients: 18 males, 2 females. [Methods] COP total distance, sway velocity, and the weight load on the paretic leg were measured while subjects performed the following three tasks (somatosensory task, cognitive-motor task, and dual task). [Results] Both COP total distance and sway velocity significantly decreased during the performance of all tasks. COP total distance and sway velocity significantly decreased during the somatosensory task and the dual task. The weight load significantly increased during performance of the somatosensory task and the dual task. [Conclusion] Compensatory mechanisms in the non-paretic leg were limited by placing it on an air cushion, and we observed an increase in somatosensory input from the paretic leg due to an enhanced weight load. PMID:25540484

  19. The effect of foot orthoses on standing foot posture and gait of young children with Down syndrome.

    PubMed

    Selby-Silverstein, L; Hillstrom, H J; Palisano, R J

    2001-01-01

    The purpose of this study was to determine if foot orthoses (FOs) immediately affected gait of children with Down Syndrome (DS) and excessively pronated feet. Subjects were 3--6 years old; 16 with DS and 10 without disabilities. Gait of children with DS wearing sneakers was compared with and without FOs and compared to gait of children without disabilities. Ankle moment, walking speed during stance phase, sneaker prints, center of pressure, and transverse plane foot angles were collected and compared. In standing, heel eversion was reduced when the children wore FOs (p=0.000). During gait the transverse plane foot angle decreased indicating more internal rotation with FOs (p=0.000). Trial-to-trial variability of pronation-supination index (p=0.0001), foot length contact (p=0.0001), transverse plane foot angle (p=0.0003), and walking speed (p=0.0001) all decreased with FO use. Trial-to-trial variability of normalized peak ankle moment (p=0.0001), and of phase of peak ankle moment (p=0.0001) increased when the children wore FOs.

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

    ERIC Educational Resources Information Center

    Granacher, Urs; Gollhofer, Albert; Kriemler, Susi

    2010-01-01

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

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

    ERIC Educational Resources Information Center

    Granacher, Urs; Gollhofer, Albert; Kriemler, Susi

    2010-01-01

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

  2. Comparison of Standing Posture Bioelectrical Impedance Analysis with DXA for Body Composition in a Large, Healthy Chinese Population

    PubMed Central

    Chen, Kuen-Tsann; Chen, Yu-Yawn; Wang, Chia-Wei; Chuang, Chih-Lin; Chiang, Li-Ming; Lai, Chung-Liang; Lu, Hsueh-Kuan; Dwyer, Gregory B.; Chao, Shu-Ping; Shih, Ming-Kuei; Hsieh, Kuen-Chang

    2016-01-01

    Bioelectrical impedance analysis (BIA) is a common method for assessing body composition in research and clinical trials. BIA is convenient but when compared with other reference methods, the results have been inconclusive. The level of obesity degree in subjects is considered to be an important factor affecting the accuracy of the measurements. A total of 711 participants were recruited in Taiwan and were sub-grouped by gender and levels of adiposity. Regression analysis and Bland-Altman analysis were used to evaluate the agreement of the measured body fat percentage (BF%) between BIA and DXA. The BF% measured by the DXA and BIA methods (Tanita BC-418) were expressed as BF%DXA and BF%BIA8, respectively. A one-way ANOVA was used to test the differences in BF% measurements by gender and levels of adiposity. The estimated BF%BIA8 and BF%DXA in the all subjects, male and female groups were all highly correlated (r = 0.934, 0.901, 0.916, all P< 0.001). The average estimated BF%BIA8 (22.54 ± 9.48%) was significantly lower than the average BF%DXA (26.26 ± 11.18%). The BF%BIA8 was overestimated in the male subgroup (BF%DXA< 15%), compared to BF%DXA by 0.45%, respectively. In the other subgroups, the BF%BIA8 values were all underestimated. Standing BIA estimating body fat percentage in Chinese participants have a high correlation, but underestimated on normal and high obesity degree in both male and female subjects. PMID:27467065

  3. Comparison of Standing Posture Bioelectrical Impedance Analysis with DXA for Body Composition in a Large, Healthy Chinese Population.

    PubMed

    Chen, Kuen-Tsann; Chen, Yu-Yawn; Wang, Chia-Wei; Chuang, Chih-Lin; Chiang, Li-Ming; Lai, Chung-Liang; Lu, Hsueh-Kuan; Dwyer, Gregory B; Chao, Shu-Ping; Shih, Ming-Kuei; Hsieh, Kuen-Chang

    2016-01-01

    Bioelectrical impedance analysis (BIA) is a common method for assessing body composition in research and clinical trials. BIA is convenient but when compared with other reference methods, the results have been inconclusive. The level of obesity degree in subjects is considered to be an important factor affecting the accuracy of the measurements. A total of 711 participants were recruited in Taiwan and were sub-grouped by gender and levels of adiposity. Regression analysis and Bland-Altman analysis were used to evaluate the agreement of the measured body fat percentage (BF%) between BIA and DXA. The BF% measured by the DXA and BIA methods (Tanita BC-418) were expressed as BF%DXA and BF%BIA8, respectively. A one-way ANOVA was used to test the differences in BF% measurements by gender and levels of adiposity. The estimated BF%BIA8 and BF%DXA in the all subjects, male and female groups were all highly correlated (r = 0.934, 0.901, 0.916, all P< 0.001). The average estimated BF%BIA8 (22.54 ± 9.48%) was significantly lower than the average BF%DXA (26.26 ± 11.18%). The BF%BIA8 was overestimated in the male subgroup (BF%DXA< 15%), compared to BF%DXA by 0.45%, respectively. In the other subgroups, the BF%BIA8 values were all underestimated. Standing BIA estimating body fat percentage in Chinese participants have a high correlation, but underestimated on normal and high obesity degree in both male and female subjects.

  4. Foot-type analysis and plantar pressure differences between obese and nonobese adolescents during upright standing.

    PubMed

    Cimolin, Veronica; Capodaglio, Paolo; Cau, Nicola; Galli, Manuela; Pau, Massimiliano; Patrizi, Alessandra; Tringali, Gabriella; Sartorio, Alessandro

    2016-03-01

    This study aimed to characterize the effect of obesity on foot-type and plantar pressure distribution in adolescents. Ten obese adolescents (obese group; BMI: 35.45±4.73 kg/m) and eight normal-weighted adolescents (control group; BMI: 18.67±2.46 kg/m) were recruited. Both groups were evaluated while standing using the Pedar-X in-shoe system. Foot-ground contact was characterized using contact area, peak of force and pressure calculated for the subareas of the foot. The analysis showed that obese participants had significantly higher area of contact in forefoot and midfoot (only in medial area) regions in comparison with the control group, whereas no statistically significant differences were observed for the rearfoot region. As far as the maximum pressure and force was concerned, similar results were obtained for both groups. Obese participants showed higher values for all the regions, with the exception of medial rearfoot area, for which the values were similar between the two groups. The analysis of foot-type distribution displayed that in the obese group high percentage of participants presented flat foot (70%) respect to cavus foot (20%) and normal foot (10%); on the contrary, in the control group, foot-types were markedly different, with 25% of participants with flat foot, 25% with cavus foot and 50% with normal foot. These results are important from a clinical perspective to develop and enhance the rehabilitative options in these patients and to avoid a worsening of their foot abnormalities. Untreated flat foot can in fact be disabling and over time can result in significant difficulties for the patient.

  5. Influence of pelvic asymmetry and idiopathic scoliosis in adolescents on postural balance during sitting.

    PubMed

    Jung, Ji-Yong; Cha, Eun-Jong; Kim, Kyung-Ah; Won, Yonggwan; Bok, Soo-Kyung; Kim, Bong-Ok; Kim, Jung-Ja

    2015-01-01

    The effects of pelvic asymmetry and idiopathic scoliosis on postural balance during sitting were studied by measuring inclination angles, pressure distribution, and electromyography. Participants were classified into a control group, pelvic asymmetry group, scoliosis group, and scoliosis with pelvic asymmetry and then performed anterior, posterior, left, and right pelvic tilting while sitting on the unstable board for 5 seconds to assess their postural balance. Inclination and obliquity angles between the groups were measured by an accelerometer located on the unstable board. Pressure distribution (maximum force and peak pressure) was analyzed using a capacitive seat sensor. In addition, surface electrodes were attached to the abdominal and erector spinae muscles of each participant. Inclination and obliquity angles increased more asymmetrically in participants with both pelvic asymmetry and scoliosis than with pelvic asymmetry or scoliosis alone. Maximum forces and peak pressures of each group showed an asymmetrical pressure distribution caused by the difference in height between the left and right pelvis and curve type of the patients' spines when performing anterior, posterior, left, and right pelvic tilting while sitting. Muscle contraction patterns of external oblique, thoracic erector spinae, lumbar erector spinae, and lumbar multifidus muscles may be influenced by spine curve type and region of idiopathic scoliosis. Asymmetrical muscle activities were observed on the convex side of scoliotic patients and these muscle activity patterns were changed by the pelvic asymmetry. From these results, it was confirmed that pelvic asymmetry and idiopathic scoliosis cause postural asymmetry, unequal weight distribution, and muscular imbalance during sitting.

  6. Evaluation of Myoelectric Activity of Paraspinal Muscles in Adolescents with Idiopathic Scoliosis during Habitual Standing and Sitting

    PubMed Central

    Kwok, Garcia; Cheung, Mei-Chun; Yick, Kit-Lun

    2015-01-01

    There is a number of research work in the literature that have applied sEMG biofeedback as an instrument for muscle rehabilitation. Therefore, sEMG is a good tool for this research work and is used to record the myoelectric activity in the paraspinal muscles of those with AIS during habitual standing and sitting. After the sEMG evaluation, the root-mean-square (RMS) sEMG values of the paraspinal muscles in the habitual postures reflect the spinal curvature situation of the PUMC Type Ia and IIc subjects. Both groups have a stronger average RMS sEMG value on the convex side of the affected muscle regions. Correction to posture as instructed by the physiotherapist has helped the subjects to achieve a more balanced RMS sEMG ratio in the trapezius and latissimus dorsi regions; the erector spinae in the thoracic region and/or erector spinae in the lumbar region. It is, therefore, considered that with regular practice of the suggested positions, those with AIS can use motor learning to achieve a more balanced posture. Consequently, the findings can be used in less intrusive early orthotic intervention and provision of care to those with AIS. PMID:26583151

  7. Evaluation of Myoelectric Activity of Paraspinal Muscles in Adolescents with Idiopathic Scoliosis during Habitual Standing and Sitting.

    PubMed

    Kwok, Garcia; Yip, Joanne; Cheung, Mei-Chun; Yick, Kit-Lun

    2015-01-01

    There is a number of research work in the literature that have applied sEMG biofeedback as an instrument for muscle rehabilitation. Therefore, sEMG is a good tool for this research work and is used to record the myoelectric activity in the paraspinal muscles of those with AIS during habitual standing and sitting. After the sEMG evaluation, the root-mean-square (RMS) sEMG values of the paraspinal muscles in the habitual postures reflect the spinal curvature situation of the PUMC Type Ia and IIc subjects. Both groups have a stronger average RMS sEMG value on the convex side of the affected muscle regions. Correction to posture as instructed by the physiotherapist has helped the subjects to achieve a more balanced RMS sEMG ratio in the trapezius and latissimus dorsi regions; the erector spinae in the thoracic region and/or erector spinae in the lumbar region. It is, therefore, considered that with regular practice of the suggested positions, those with AIS can use motor learning to achieve a more balanced posture. Consequently, the findings can be used in less intrusive early orthotic intervention and provision of care to those with AIS.

  8. The relationship between sitting posture and seated-related upper quadrant musculoskeletal pain in computing South African adolescents: A prospective study.

    PubMed

    Brink, Yolandi; Louw, Quinette; Grimmer, Karen; Jordaan, Esmè

    2015-12-01

    There is evidence that consistent sitting for prolonged periods is associated with upper quadrant musculoskeletal pain (UQMP). It is unclear whether postural alignment is a significant risk factor. The aim of the prospective study (2010-2011) was to ascertain if three-dimensional sitting postural angles, measured in a real-life school computer classroom setting, predict seated-related UQMP. Asymptomatic Grade 10 high-school students, aged 15-17 years, undertaking Computer Application Technology, were eligible to participate. Using the 3D Posture Analysis Tool, sitting posture was measured while students used desk-top computers. Posture was reported as five upper quadrant angles (Head flexion, Neck flexion; Craniocervical angle, Trunk flexion and Head lateral bending). The Computer Usage Questionnaire measured seated-related UQMP and hours of computer use. The Beck Depression Inventory and the Multidimensional Anxiety Scale for Children assessed psychosocial factors. Sitting posture, computer use and psychosocial factors were measured at baseline. UQMP was measured at six months and one-year follow-up. 211, 190 and 153 students participated at baseline, six months and one-year follow-up respectively. 34.2% students complained of seated-related UQMP during the follow-up period. Increased head flexion (HF) predicted seated-related UQMP developing over time for a small group of students with pain scores greater than the 90th pain percentile, adjusted for age, gender, BMI, computer use and psychosocial factors (p = 0.003). The pain score increased 0.22 points per 1° increase in HF. Classroom ergonomics and postural hygiene should therefore focus on reducing large HF angles among computing adolescents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Standing Tall: The Benefits of Standing Devices

    ERIC Educational Resources Information Center

    Warner, Mark P.

    2007-01-01

    In the author's opinion as a pediatric physical therapist, with the exception of a wheelchair, there is no other piece of assistive technology that is more beneficial to children and adults with special needs than a standing device. Postural symmetry during standing and walking activities is extremely important for everyone. Very few children…

  10. Standing Tall: The Benefits of Standing Devices

    ERIC Educational Resources Information Center

    Warner, Mark P.

    2007-01-01

    In the author's opinion as a pediatric physical therapist, with the exception of a wheelchair, there is no other piece of assistive technology that is more beneficial to children and adults with special needs than a standing device. Postural symmetry during standing and walking activities is extremely important for everyone. Very few children…

  11. Perception-Action and Adaptation in Postural Control of Children and Adolescents with Cerebral Palsy

    ERIC Educational Resources Information Center

    Barela, Jose A.; Focks, Grietje M. Jaspers; Hilgeholt, Toke; Barela, Ana M. F.; Carvalho, Raquel de P.; Savelsbergh, Geert J. P.

    2011-01-01

    The aim of this study was to examine the coupling between visual information and body sway and the adaptation in this coupling of individuals with cerebral palsy (CP). Fifteen children with and 15 without CP, 6-15 years old, were required to stand upright inside of a moving room. All children first performed two trials with no movement of the room…

  12. Perception-Action and Adaptation in Postural Control of Children and Adolescents with Cerebral Palsy

    ERIC Educational Resources Information Center

    Barela, Jose A.; Focks, Grietje M. Jaspers; Hilgeholt, Toke; Barela, Ana M. F.; Carvalho, Raquel de P.; Savelsbergh, Geert J. P.

    2011-01-01

    The aim of this study was to examine the coupling between visual information and body sway and the adaptation in this coupling of individuals with cerebral palsy (CP). Fifteen children with and 15 without CP, 6-15 years old, were required to stand upright inside of a moving room. All children first performed two trials with no movement of the room…

  13. Stability analysis of paraplegic standing while wearing an orthosis.

    PubMed

    Kagawa, Takahiro; Fukuda, Hiroshi; Hiroshi, Fukuda; Uno, Yoji; Yoji, Uno

    2006-10-01

    Paraplegics can maintain a standing posture, called the "C-posture", while wearing an orthosis. The significant feature of the C-posture is that the body's center of mass is located behind the hip joint. In this study, we investigate the C-posture mechanism and assess the relationship between posture and stability, the aim being to restore standing function. We first measured the standing postures of paraplegic subjects wearing an orthosis. The subjects maintained the standing posture for 30 s. Next, assuming the C-posture to be an equilibrium attractor in the musculoskeletal system, we used a dynamic model of the musculoskeletal system to analyze the relationship between posture and stability, and also to assess the influence of ankle stiffness. We calculated the standing posture on the basis of a return map. The calculated standing postures show some features of the C-posture. The stability analysis revealed that, despite a limitation in the range of stable postures, the C-posture is more stable than the postures of normal people. The results suggest that although the C-posture is an appropriate posture for paraplegic standing, sufficient ankle stiffness and an appropriate alignment of ankle angle are necessary and preventing hip flexion movements is desirable.

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

    PubMed

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

    2002-04-01

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

  15. Home use of a functional electrical stimulation system for standing and mobility in adolescents with spinal cord injury.

    PubMed

    Moynahan, M; Mullin, C; Cohn, J; Burns, C A; Halden, E E; Triolo, R J; Betz, R R

    1996-10-01

    Functional electrical stimulation (FES) is a technology that may allow some patients with spinal cord injury (SCI) to integrate standing and upright mobility with wheelchair mobility. The purpose of this study was to document the patterns of home and community use of a FES system for standing and mobility. A telephone questionnaire was administered every 1 to 4 weeks for a minimum of 1 year. An interview was given at the end of the study to probe the motivators and barriers to home use. Training for use of the FES system was performed in an inpatient pediatric rehabilitation setting. Data collection began after the subjects were discharged to home. Five adolescents with complete, thoracic-level SCI. Subjects participated in a program of FES exercise followed by training in basic mobility skills such as standing transfers, maneuvering, level ambulation, one-handed and reaching activities, and stair ascent/descent. The frequency with which the FES system was used at home and the activities for which it was utilized were documented. Motivators and barriers to FES home use were examined. Subjects donned the FES system on the average once every 3 to 4 days. Between 51% and 84% of the times donned, the system was used for exercise. The remaining times it was used for standing activities, most commonly reaching, one-handed tasks, and standing for exercise. "Motivators" included being able to do things that would otherwise be difficult, perceiving a healthful benefit or a sense of well-being from standing and exercise, and feeling an obligation to stand as a participant in a research study. "Barriers" to FES use included not finding time to use the system, having difficulty seeing opportunities to stand, and being reluctant to wear the FES system all day.

  16. Reliability of upright posture measurements in primary school children.

    PubMed

    McEvoy, Maureen P; Grimmer, Karen

    2005-06-29

    Correct upright posture is considered to be a measure of good musculoskeletal health. Little is known about the usual variability of children's upright standing posture. The aim of this study was to assess differences between repeated measures of upright posture in a group of primary school children. Sagittal plane photographs of usual, relaxed upright standing posture of 38 boys and girls aged 5-12 years were taken twice within an hour. Reflective markers were placed over the canthus, tragus, C7 spinous process, greater trochanter and lateral malleolus. Digitising software was used to calculate the x,y plane coordinates, from which five postural angles were calculated (trunk, neck, gaze, head on neck, lower limb). Height, weight, motor control estimates (as measured by the Brace Tests) and presence of recent pain were recorded for each child, and the association between the first test measure of posture angles and these factors was assessed using linear regression and ANOVA models. Multiple ANOVA models were applied to analyse the effect of repeated testing, and significant predictors on the angles. Four of the five postural angles (trunk, neck, head on neck, lower limb) were significantly influenced by age. As age was strongly associated with height (r2 = 0.84) and moderately associated with weight and motor control (r2 = 0.67, 0.56 respectively), these developmental parameters may well explain the age effect on angles. There was no relationship between age and pain reported on either the testing day, or recently, and there was no gender influence on any angle. There was no significant effect of repeated testing on any angle (ICC>0.93). None of the hypothesized predictors were associated with differences in angles from repeated testing. This study outlined the variability of relaxed upright standing posture of children aged 5-12 years, when measured twice in an hour. Age influenced the size of the angles but not the variability. While the subject numbers in this

  17. Reliability of upright posture measurements in primary school children

    PubMed Central

    McEvoy, Maureen P; Grimmer, Karen

    2005-01-01

    Background Correct upright posture is considered to be a measure of good musculoskeletal health. Little is known about the usual variability of children's upright standing posture. The aim of this study was to assess differences between repeated measures of upright posture in a group of primary school children. Methods Sagittal plane photographs of usual, relaxed upright standing posture of 38 boys and girls aged 5–12 years were taken twice within an hour. Reflective markers were placed over the canthus, tragus, C7 spinous process, greater trochanter and lateral malleolus. Digitising software was used to calculate the x,y plane coordinates, from which five postural angles were calculated (trunk, neck, gaze, head on neck, lower limb). Height, weight, motor control estimates (as measured by the Brace Tests) and presence of recent pain were recorded for each child, and the association between the first test measure of posture angles and these factors was assessed using linear regression and ANOVA models. Multiple ANOVA models were applied to analyse the effect of repeated testing, and significant predictors on the angles. Results Four of the five postural angles (trunk, neck, head on neck, lower limb) were significantly influenced by age. As age was strongly associated with height (r2 = 0.84) and moderately associated with weight and motor control (r2 = 0.67, 0.56 respectively), these developmental parameters may well explain the age effect on angles. There was no relationship between age and pain reported on either the testing day, or recently, and there was no gender influence on any angle. There was no significant effect of repeated testing on any angle (ICC>0.93). None of the hypothesized predictors were associated with differences in angles from repeated testing. Conclusion This study outlined the variability of relaxed upright standing posture of children aged 5–12 years, when measured twice in an hour. Age influenced the size of the angles but not the

  18. Relationships between Task-Oriented Postural Control and Motor Ability in Children and Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Wang, Hui-Yi; Long, I-Man; Liu, Mei-Fang

    2012-01-01

    Individuals with Down syndrome (DS) have been characterized by greater postural sway in quiet stance and insufficient motor ability. However, there is a lack of studies to explore the properties of dynamic postural sway, especially under conditions of task-oriented movement. The purpose of this study was to investigate the relationships between…

  19. Relationships between Task-Oriented Postural Control and Motor Ability in Children and Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Wang, Hui-Yi; Long, I-Man; Liu, Mei-Fang

    2012-01-01

    Individuals with Down syndrome (DS) have been characterized by greater postural sway in quiet stance and insufficient motor ability. However, there is a lack of studies to explore the properties of dynamic postural sway, especially under conditions of task-oriented movement. The purpose of this study was to investigate the relationships between…

  20. Perception-action and adaptation in postural control of children and adolescents with cerebral palsy.

    PubMed

    Barela, José A; Focks, Grietje M Jaspers; Hilgeholt, Toke; Barela, Ana M F; Carvalho, Raquel de P; Savelsbergh, Geert J P

    2011-01-01

    The aim of this study was to examine the coupling between visual information and body sway and the adaptation in this coupling of individuals with cerebral palsy (CP). Fifteen children with and 15 without CP, 6-15 years old, were required to stand upright inside of a moving room. All children first performed two trials with no movement of the room and eyes open or closed, then four trials in which the room oscillated at 0.2 or 0.5 Hz (peak velocity of 0.6 cm/s), one trial in which the room oscillated at 0.2 Hz (peak velocity of 3.5 cm/s), and finally two other trials in which the room oscillated again at 0.2 Hz (peak velocity of 0.6 cm/s). Participants with CP coupled body sway to visual information provided by the moving room, comparable to the coupling of participants without CP. However, participants with CP exhibited larger body sway in maintaining upright position and more variable sway when body sway was induced by visual manipulation. They showed adaptive sensory motor coupling, e.g. down-weighting visual influence when a larger stimulus was provided, but not with the same magnitude as typically developing participants. This indicates that participants with CP have less capability of adaptation.

  1. Early Adolescents' Social Standing in Peer Groups: Behavioral Correlates of Stability and Change

    ERIC Educational Resources Information Center

    Lansford, Jennifer E.; Killeya-Jones, Ley A.; Miller, Shari; Costanzo, Philip R.

    2009-01-01

    Sociometric nominations, social cognitive maps, and self-report questionnaires were completed in consecutive years by 327 students (56% girls) followed longitudinally from grade 7 to grade 8 to examine the stability of social standing in peer groups and correlates of changes in social standing. Social preference, perceived popularity, network…

  2. Early Adolescents' Social Standing in Peer Groups: Behavioral Correlates of Stability and Change

    ERIC Educational Resources Information Center

    Lansford, Jennifer E.; Killeya-Jones, Ley A.; Miller, Shari; Costanzo, Philip R.

    2009-01-01

    Sociometric nominations, social cognitive maps, and self-report questionnaires were completed in consecutive years by 327 students (56% girls) followed longitudinally from grade 7 to grade 8 to examine the stability of social standing in peer groups and correlates of changes in social standing. Social preference, perceived popularity, network…

  3. Correlation between rounded shoulder posture, neck disability indices, and degree of forward head posture.

    PubMed

    Kim, Eun-Kyung; Kim, Jin Seop

    2016-10-01

    [Purpose] The present study aimed to examine the correlation between rounded shoulder posture, neck disability indices and the degree of forward head posture. [Subjects and Methods] Subjects aged 19-24 years were selected for this study, and the craniovertebral angle was used to measure the degree of forward head posture in the standing and seated positions. Vernier calipers were used to measure rounded shoulder posture in the supine position, and neck pain and functional disability were assessed using neck disability indices. [Results] Angle and neck disability indices in both standing and sitting posture positions exhibited a significant inverse relationship. However, no significant correlation was detected between the craniovertebral angle and rounded shoulder posture for the standing and sitting posture positions. [Conclusion] In conclusion, it was demonstrated in the present study that, depending on the degree of forward head posture, changes were detected in the neck disability indices. However, even an increase in the forward head tilt angle did not lead to rounded shoulder posture. Therefore, maintaining proper posture may prevent postural pain syndrome, functional disability, and postural deformity.

  4. Correlation between rounded shoulder posture, neck disability indices, and degree of forward head posture

    PubMed Central

    Kim, Eun-Kyung; Kim, Jin Seop

    2016-01-01

    [Purpose] The present study aimed to examine the correlation between rounded shoulder posture, neck disability indices and the degree of forward head posture. [Subjects and Methods] Subjects aged 19–24 years were selected for this study, and the craniovertebral angle was used to measure the degree of forward head posture in the standing and seated positions. Vernier calipers were used to measure rounded shoulder posture in the supine position, and neck pain and functional disability were assessed using neck disability indices. [Results] Angle and neck disability indices in both standing and sitting posture positions exhibited a significant inverse relationship. However, no significant correlation was detected between the craniovertebral angle and rounded shoulder posture for the standing and sitting posture positions. [Conclusion] In conclusion, it was demonstrated in the present study that, depending on the degree of forward head posture, changes were detected in the neck disability indices. However, even an increase in the forward head tilt angle did not lead to rounded shoulder posture. Therefore, maintaining proper posture may prevent postural pain syndrome, functional disability, and postural deformity. PMID:27821964

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

    PubMed

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

    2013-04-01

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

  6. Ultrasound measurement of deep and superficial abdominal muscles thickness during standing postural tasks in participants with and without chronic low back pain.

    PubMed

    Ehsani, Fatemeh; Arab, Amir Massoud; Jaberzadeh, Shapour; Salavati, Mahyar

    2016-06-01

    Activity of deep abdominal muscles increases the lumbar stability. Majority of previous studies indicated abdominal muscle activity dysfunction during static activity in patients with low back pain (LBP). However, the number of studies that evaluated deep abdominal muscle activity in dynamic standing activities in patients is limited, while this assessment provides better understanding of pain behavior during these activities. Investigation of superficial and deep abdominal muscles activity in participants with chronic LBP as compared to healthy individuals during standing tasks. Case control study. Ultrasound imaging was used to measure the thickness of transverse abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles in female participants with (N = 45) and without chronic LBP (CLBP) (N = 45) during tests. The Biodex Balance System was used to provide standing tasks. The thickness of each muscle in a standing task was normalized to actual thickness at rest in the supine lying position to estimate its activity. The results indicate increases in thickness of all muscles in both groups during dynamic as compared to static standing tasks (P < 0.05, ES > 0.5). Lower percentages of thickness change for TrA muscle and higher for EO muscle were found in the patients as compared to healthy individuals during all tests (P < 0.05, ES > 1.28). Higher activity of superficial than deep abdominal muscles in patients as compared to healthy individuals during standing tasks indicates motor control dysfunction in patients with CLBP. Standing tasks can discriminate the individuals with and without LBP and can be progressively used in training. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Effects of rehabilitative horse riding on the Sit-to-Stand action of the adolescent with brain lesions

    PubMed Central

    Lee, Jang Won; Han, A-reum; Kim, Kihong

    2014-01-01

    The purpose of this study was to investigate the balance abilities of the adolescent girl with brain lesions by Sit-to-Stand (STS) action analysis before and after the rehabilitative horse riding of 16 week program. The subject aged 16 yr old who had the disabilities of spasticity and hemiplegia was recruited with the consent approval. The equilibrium abilities of the subject were tested by Sit-to-Stand examination with Weight Transfer Time (WTT), Mean Rising Index (MRI), Mean Weight Asymmetry (MWA), Max Trunk Flexion Velocity (MTFV), and Max Trunk Extension Velocity (MTEV). Research was designed by AB single subject study with baseline of 3 times of measurement and rehabilitative horse riding treatments. In the results, the enhancement of the subject’s equilibrium ability was shown from the comparisons between baseline and treatment by the STS test that WTT was 2.37 sec faster, MRI was 6.64 N/kg higher, and MWA was 8.12% lower, and MTFV was 0.57°/sec larger than all those means of baseline. It suggested that the subject showed her enhanced balance ability while in sitting and standing after the rehabilitative horse riding treatments. PMID:24678502

  8. Postural threat influences conscious perception of postural sway.

    PubMed

    Cleworth, Taylor W; Carpenter, Mark G

    2016-05-04

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

  9. "A Chance to Stand Back": Parenting Programmes for Parents of Adolescents

    ERIC Educational Resources Information Center

    Clarke, Karen; Churchill, Harriet

    2012-01-01

    Parenting interventions were an important feature of New Labour's policies to combat social exclusion. This paper critically examines parenting programmes for families with adolescents, assessing national and local policy aims against the perspectives of women who took part in a parenting course, which was the subject of a local evaluation. The…

  10. "A Chance to Stand Back": Parenting Programmes for Parents of Adolescents

    ERIC Educational Resources Information Center

    Clarke, Karen; Churchill, Harriet

    2012-01-01

    Parenting interventions were an important feature of New Labour's policies to combat social exclusion. This paper critically examines parenting programmes for families with adolescents, assessing national and local policy aims against the perspectives of women who took part in a parenting course, which was the subject of a local evaluation. The…

  11. Optimization of the examination posture in spinal curvature assessment

    PubMed Central

    2012-01-01

    To decrease the influence of postural sway during spinal measurements, an instrumented fixation posture (called G) was proposed and tested in comparison with the free standing posture (A) using the DTP-3 system in a group of 70 healthy volunteers. The measurement was performed 5 times on each subject and each position was tested by a newly developed device for non-invasive spinal measurements called DTP-3 system. Changes in postural stability of the spinous processes for each subject/the whole group were evaluated by employing standard statistical tools. Posture G, when compared to posture A, reduced postural sway significantly in all spinous processes from C3 to L5 in both the mediolateral and anterioposterior directions. Posture G also significantly reduced postural sway in the vertical direction in 18 out of 22 spinous processes. Importantly, posture G did not significantly influence the spinal curvature. PMID:22546519

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

    PubMed

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

    2012-04-30

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

  13. An effect of posture on anticipatory anxiety.

    PubMed

    Lipnicki, Darren M; Byrne, Don G

    2008-02-01

    This study investigated the effects of body posture on state anxiety and psychological stress. Twenty normal adults performed a demanding mental arithmetic task in both standing and supine conditions, with subjective measures of anxiety and stress obtained before, immediately, and 10 min after the task. Participants were found to experience anticipatory anxiety when standing, although not when supine. The mechanism underlying this effect remains to be determined, although it could involve a postural difference in baroreceptor load.

  14. A reliable technique for the assessment of posture: assessment criteria for aspects of posture.

    PubMed

    Watson, A W; Mac Donncha, C

    2000-09-01

    The purposes of this study were: a) to describe assessment criteria for 10 separate aspects of posture; b) to describe the development and use of a qualitative posture rating scale based on the above; and c) to establish the reliability of the assessment technique. Experimental design. Observation and photographic record of the posture of a sample of adolescent males. Reliability determined using two observations separated by a period of seven days. 114 adolescent males (age, 15-17 yrs) randomly selected from two post-primary schools. Ten different aspects of posture assessed according to defined criteria. Assessments made from four photographs: anterior, posterior, lateral and oblique views. Through examination of the photographs a qualitative postural assessment scale was developed. This consisted of three categories for each aspect of posture, corresponding to: good posture, moderate defect, and severe defect. Definite assessment criteria for each of the 10 aspects of posture have been described. The above has resulted in an assessment procedure in which the reproducibility of the posture scores exceeded 85 % for all aspects assessed. Definite criteria for the examination of 10 different aspects of posture have been described and clear diagrams representing good posture, moderate and severe defects have been produced. The reproducibility of the assessment procedure described makes it suitable for investigating the relationships between posture and other health variables such as musculo-skeletal disorders.

  15. Sagittal Spinal Morphology in Highly Trained Adolescent Tennis Players

    PubMed Central

    Muyor, José M.; Sánchez-Sánchez, Estefanía; Sanz-Rivas, David; López-Miñarro, Pedro A.

    2013-01-01

    Sports with a predominance of forward-bending and extension postures have been associated with alterations in the sagittal spinal curvatures and greater risk of spinal injury. Because, the tennis players adopt these postures, the aims of this study were: 1) to describe spinal curvatures and pelvic tilt in male and female highly trained adolescent tennis players during relaxed standing posture and with thoracic spine corrected (in prone lying on the floor); and 2) to determine the frequency of thoracic hyperkyphosis and lumbar hypo/hyper lordosis in these postures. Forty adolescent tennis players (24 male and 16 female) aged 13-18 years, participated voluntarily in this study. The Spinal Mouse system was used to measure sagittal spinal curvatures and pelvic tilt. The mean values in the relaxed standing posture were 43.83° ± 7.87° (thoracic kyphosis), - 27.58° ± 7.01° (lumbar lordosis), and 13.38° ± 5.57° (pelvic tilt) for male tennis players, respectively; and 36.13° ± 6.69° (thoracic kyphosis), - 32.69° ± 5.06° (lumbar lordosis), 20.94° ± 5.36° (pelvic tilt) for female tennis players (p < 0.05 between genders in all spinal parameters). The male and female tennis players showed a frequency of 62.5% and 93.8% (p = 0.032) for neutral thoracic kyphosis, and 83.3% and 93.8% (p = 0.062) in neutral lumbar lordosis, respectively. In conclusion, due to the high percentage of neutral spinal curvatures in both male and female tennis players, to practice tennis in these levels does not alter sagittal spinal morphology in the relaxed standing posture in adolescent highly trained tennis players. Key Points This study evaluated thoracic and lumbar spinal curvatures and pelvic tilt during several postures in young highly trained tennis players. Female tennis players showed statistically significant greater anterior pelvic tilt, lumbar lordosis and lower thoracic kyphosis than male tennis players. The high percentage of neutral thoracic kyphosis and lumbar

  16. Free-Standing Canes.

    ERIC Educational Resources Information Center

    Ehresman, Paul

    1995-01-01

    A precane device, called the "free-standing cane," was developed to help children with blindness along with other disabilities. The cane detects obstacles; guides the user's hands into a relaxed, static position in front of the hips; facilitates postural security and control; and offers tactile and kinesthetic feedback. (JDD)

  17. Free-Standing Canes.

    ERIC Educational Resources Information Center

    Ehresman, Paul

    1995-01-01

    A precane device, called the "free-standing cane," was developed to help children with blindness along with other disabilities. The cane detects obstacles; guides the user's hands into a relaxed, static position in front of the hips; facilitates postural security and control; and offers tactile and kinesthetic feedback. (JDD)

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

    PubMed

    Aruin, Alexander S

    2006-06-19

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

  19. Postural performance of vestibular loss patients under increased postural threat.

    PubMed

    Young, Laurence R; Bernard-Demanze, Laurence; Dumitrescu, Michel; Magnan, Jacques; Borel, Liliane; Lacour, Michel

    2012-01-01

    The effects of increasing postural task difficulty on balance control was investigated in 9 compensated vestibular loss patients whose results were compared to 11 healthy adults. Subjects were tested in static (stable support) and dynamic (sinusoidal translation of the support) conditions, both at floor level and at height (62 cm above the floor), and with and without vision, to create an additional postural threat. Wavelet analysis of the center of foot pressure displacement and motion analysis of the body segments were used to evaluate the postural performance. Evaluation questionnaires were used to examine the compensation level of the patients (DHI test), their general anxiety level (SAST), fear of height (subjective scale), and workload (NASA TLX test). (Vestibular loss patients rely more on vision and spend more energy maintaining balance than controls, but they use the same postural strategy as normals in both static and dynamic conditions.) Questionnaire data all showed differences in behavior and perceptions between the controls and the patients. However, at height and without vision, a whole body strategy leading to rigid posture replaces the head stabilization strategy found for standing at floor level. The effects of height on postural control can be attributable to an increase in postural threat and attention changes resulting from modifications in perception.

  20. Prediction of fatness by standing 8-electrode bioimpedance: a multiethnic adolescent population.

    PubMed

    Sluyter, John D; Schaaf, David; Scragg, Robert K R; Plank, Lindsay D

    2010-01-01

    The objective of this study was to validate an 8-electrode bioimpedance analysis (BIA(8)) device (BC-418; Tanita, Tokyo, Japan) for use in populations of European, Maori, Pacific Island, and Asian adolescents. Healthy adolescents (215 M, 216 F; 129 Pacific Island, 120 Asian, 91 Maori, and 91 European; age range 12-19 years) were recruited by purposive sampling of high schools in Auckland, New Zealand. Weight, height, sitting height, leg length, waist circumference, and whole-body impedance were measured. Fat mass (FM) and fat-free mass (FFM) derived from the BIA(8) manufacturer's equations were compared with measurements by dual-energy X-ray absorptiometry (DXA). DXA-measured FFM was used as the reference to develop prediction equations based on impedance. A double cross-validation technique was applied. BIA(8) underestimated FM by 2.06 kg (P < 0.0001) and percent body fat (%BF) by 2.84% (P < 0.0001), on average. However, BIA(8) tended to overestimate FM and %BF in lean and underestimate FM and %BF in fat individuals. Sex-specific equations developed showed acceptable accuracy on cross-validation. In the total sample, the best prediction equations were, for boys: FFM (kg) = 0.607 height (cm)(2)/impedance ( ohm) + 1.542 age (y) + 0.220 height (cm) + 0.096 weight (kg) + 1.836 ethnicity (0 = European or Asian, 1 = Maori or Pacific) - 47.547, R(2) = 0.93, standard error of estimate (SEE) = 3.09 kg; and, for girls: FFM (kg) = 0.531 height (cm)(2)/impedance ( ohm) + 0.182 height (cm) + 0.096 weight (kg) + 1.562 ethnicity (0 = non-Pacific, 1 = Pacific) - 15.782, R(2) = 0.91, SEE = 2.19 kg. In conclusion, equations for fatness estimation using BIA(8) developed for our sample perform better than reliance on the manufacturer's estimates. The relationship between BIA and body composition in adolescents is ethnicity dependent.

  1. Reliability and minimal detectable change of spinal length and width measurements using the Flexicurve for usual standing posture in healthy young adults.

    PubMed

    Dunleavy, Kim; Mariano, Herman; Wiater, Timothy; Goldberg, Allon

    2010-01-01

    The purposes of this study were to: 1) investigate the inter-rater and intra-rater reliability of use of the Flexicurve for measurement of spinal length (L), thoracic (TL) and lumbar length (LL), thoracic (TW) and lumbar width (LW), and 2) quantify measurement error and minimal detectable change at the 95% CI (MDC95) for the same measurements. Flexicurve measurements of the thoracolumbar spine were recorded by two examiners in standing. Intra-class correlation coefficients were calculated to determine the intra- and inter-rater reliability. Measurement error and MDC95 were calculated to determine length and width measurements that would constitute real change in spinal curvature. Thoracolumbar length (L) measurements had the highest degree of intra-rater reliability (0.93), while TL, TW, LL, LW showed moderate to good intra-rater reliability (0.61-0.80). Inter-rater reliability for all measurements was moderate (0.58-0.72). Measurement error was moderate to high for TW, LL, and LW (15-25%), and low for L and TL (1-6%). The %MDC95 for TW, LL, and LW found in this study was high (>40%), but was low for L (3.5%). Thoracolumbar length measurement with the Flexicurve showed good intra-rater reliability, low measurement error, and low MDC95 and may be a useful measure in clinical practice.

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

    PubMed

    Silva, Anabela G; Johnson, Mark I

    2013-06-01

    Proprioceptive afferent input from neck muscles plays an important role in postural control. Forward head posture has the potential to impair proprioceptive information from neck muscles and contribute to postural control deficits in patients with neck pain. This study investigated whether induced forward head posture affects postural control in healthy participants when compared to natural head posture. Centre of pressure sway area, distance covered and mean velocity were measured during 30s of static standing using a force platform with 25 healthy individuals (mean age ± SD = 20.76 ± 2.19 years) in 8 different conditions. Base of support, eyes open or closed and natural or forward head posture varied within these testing conditions. The majority of comparisons between natural and forward head posture were not statistically significant (p>0.05). This suggests that induced forward head posture in young healthy adults does not challenge them enough to impair postural control. Future studies should evaluate whether forward head posture affects postural control of individuals with chronic neck pain. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Postural Stability is Altered by Blood Shift

    NASA Astrophysics Data System (ADS)

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

    2008-06-01

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

  4. Posture alters human resting-state.

    PubMed

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

    2014-09-01

    Neuroimaging is ubiquitous; however, neuroimagers seldom investigate the putative impact of posture on brain activity. Whereas participants in most psychological experiments sit upright, many prominent neuroimaging techniques (e.g., functional magnetic resonance imaging (fMRI)) require participants to lie supine. Such postural discrepancies may hold important implications for brain function in general and for fMRI in particular. We directly investigated the effect of posture on spontaneous brain dynamics by recording scalp electrical activity in four orthostatic conditions (lying supine, inclined at 45°, sitting upright, and standing erect). Here we show that upright versus supine posture increases widespread high-frequency oscillatory activity. Our electroencephalographic findings highlight the importance of posture as a determinant in neuroimaging. When generalizing supine imaging results to ecological human cognition, therefore, cognitive neuroscientists would benefit from considering the influence of posture on brain dynamics. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2016-04-01

    The purpose of this study was to investigate the integration of bimanual rhythmic movements and posture in expert marching percussionists. Participants (N=11) performed three rhythmic manual tasks [1:1, 2:3, and 2:3-F (2:3 rhythm played faster at a self-selected tempo)] in one of three postures: sitting, standing on one foot, and standing on two feet. Discrete relative phase, postural time-to-contact, and coherence analysis were used to analyze the performance of the manual task, postural control, and the integration between postural and manual performance. Across all three rhythms, discrete relative phase mean and variability results showed no effects of posture on rhythmic performance. The complexity of the manual task (1:1 vs. 2:3) had no effect on postural time-to-contact. However, increasing the tempo of the manual task (2:3 vs. 2:3-F) did result in a decreased postural time-to-contact in the two-footed posture. Coherence analysis revealed that the coupling between the postural and manual task significantly decreased as a function of postural difficulty (going from a two-footed to a one-footed posture) and rhythmic complexity (1:1 vs. 2:3). Taken together, these results demonstrate that expert marching percussionists systematically decouple postural and manual fluctuations in order to preserve the performance of the rhythmic movement task. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Standing on a declining surface reduces transient prolonged standing induced low back pain development.

    PubMed

    Gallagher, Kaitlin M; Callaghan, Jack P

    2016-09-01

    While alternating standing position on a sloped surface has proven successful at reducing low back pain during standing, the purpose of this study was to evaluate standing solely on a declining surface to isolate the influence of the postural change. Seventeen participants performed two 75-min prolonged standing occupational simulations- level ground and declining surface. Fifty-three percent of participants (9/17) were categorized as pain developers during the level ground standing condition. For these same pain developers, their average maximum pain scores were 58% lower during sloped standing. All participants showed greater hip flexion, trunk-to-thigh angle flexion, and posterior translation of the trunk center of gravity when standing on the sloped surface. These postural changes could cause the muscles crossing the hip posteriorly to increase passive stiffness and assist with stabilizing the pelvis. This study stresses the importance of hip kinematics, not just lumbar spine posture, in reducing prolonged standing induced low back pain.

  7. A model of postural control in quiet standing: robust compensation of delay-induced instability using intermittent activation of feedback control.

    PubMed

    Asai, Yoshiyuki; Tasaka, Yuichi; Nomura, Kunihiko; Nomura, Taishin; Casadio, Maura; Morasso, Pietro

    2009-07-08

    The main purpose of this study is to compare two different feedback controllers for the stabilization of quiet standing in humans, taking into account that the intrinsic ankle stiffness is insufficient and that there is a large delay inducing instability in the feedback loop: 1) a standard linear, continuous-time PD controller and 2) an intermittent PD controller characterized by a switching function defined in the phase plane, with or without a dead zone around the nominal equilibrium state. The stability analysis of the first controller is carried out by using the standard tools of linear control systems, whereas the analysis of the intermittent controllers is based on the use of Poincaré maps defined in the phase plane. When the PD-control is off, the dynamics of the system is characterized by a saddle-like equilibrium, with a stable and an unstable manifold. The switching function of the intermittent controller is implemented in such a way that PD-control is 'off' when the state vector is near the stable manifold of the saddle and is 'on' otherwise. A theoretical analysis and a related simulation study show that the intermittent control model is much more robust than the standard model because the size of the region in the parameter space of the feedback control gains (P vs. D) that characterizes stable behavior is much larger in the latter case than in the former one. Moreover, the intermittent controller can use feedback parameters that are much smaller than the standard model. Typical sway patterns generated by the intermittent controller are the result of an alternation between slow motion along the stable manifold of the saddle, when the PD-control is off, and spiral motion away from the upright equilibrium determined by the activation of the PD-control with low feedback gains. Remarkably, overall dynamic stability can be achieved by combining in a smart way two unstable regimes: a saddle and an unstable spiral. The intermittent controller exploits the

  8. A Model of Postural Control in Quiet Standing: Robust Compensation of Delay-Induced Instability Using Intermittent Activation of Feedback Control

    PubMed Central

    Asai, Yoshiyuki; Tasaka, Yuichi; Nomura, Kunihiko; Nomura, Taishin; Casadio, Maura; Morasso, Pietro

    2009-01-01

    The main purpose of this study is to compare two different feedback controllers for the stabilization of quiet standing in humans, taking into account that the intrinsic ankle stiffness is insufficient and that there is a large delay inducing instability in the feedback loop: 1) a standard linear, continuous-time PD controller and 2) an intermittent PD controller characterized by a switching function defined in the phase plane, with or without a dead zone around the nominal equilibrium state. The stability analysis of the first controller is carried out by using the standard tools of linear control systems, whereas the analysis of the intermittent controllers is based on the use of Poincaré maps defined in the phase plane. When the PD-control is off, the dynamics of the system is characterized by a saddle-like equilibrium, with a stable and an unstable manifold. The switching function of the intermittent controller is implemented in such a way that PD-control is ‘off’ when the state vector is near the stable manifold of the saddle and is ‘on’ otherwise. A theoretical analysis and a related simulation study show that the intermittent control model is much more robust than the standard model because the size of the region in the parameter space of the feedback control gains (P vs. D) that characterizes stable behavior is much larger in the latter case than in the former one. Moreover, the intermittent controller can use feedback parameters that are much smaller than the standard model. Typical sway patterns generated by the intermittent controller are the result of an alternation between slow motion along the stable manifold of the saddle, when the PD-control is off, and spiral motion away from the upright equilibrium determined by the activation of the PD-control with low feedback gains. Remarkably, overall dynamic stability can be achieved by combining in a smart way two unstable regimes: a saddle and an unstable spiral. The intermittent controller

  9. Arch of the foot and postural balance in young judokas and peers.

    PubMed

    Jankowicz-Szymanska, Agnieszka; Mikolajczyk, Edyta; Wardzala, Robert

    2015-09-01

    Twenty-nine male judocas and nontraining peers participated in this study. The arch of the foot (as Clarke's angular values) was measured under non-weight-bearing conditions in two-leg and one-leg stands. Postural balance was assessed by the Flamingo balance test. Judocas presented better static balance and higher arches of the foot. Significant differences in Clarke's angular values in a sitting and standing on two-leg position were found in both groups. After transition to a one-leg stand, the height of the arches of the foot in nontraining participants was still significantly decreased. Weight bearing did not affect Clarke's angular values in judokas. A correlation was found between the Flamingo test and Clarke's angle. Better balance was observed in adolescents with higher arch of the foot.

  10. Comparison of Biodynamic Responses in Standing and Seated Human Bodies

    NASA Astrophysics Data System (ADS)

    MATSUMOTO, Y.; GRIFFIN, M. J.

    2000-12-01

    The dynamic responses of the human body in a standing position and in a sitting position have been compared. The apparent mass and transmissibilities to the head, six locations along the spine, and the pelvis were measured with eight male subjects exposed to vertical whole-body vibration. In both postures, the principal resonance in the apparent mass occurred in the range 5-6 Hz, with slightly higher frequencies and lower apparent mass in the standing posture. There was greater transmission of vertical vibration to the pelvis and the lower spine and greater relative motion within the lower spine in the standing posture than in the sitting posture at the principal resonance and at higher frequencies. Transmissibilities from the supporting surface (floor or seat) to the thoracic region had similar magnitudes for both standing and sitting subjects. The lumbar spine has less lordosis and may be more compressed and less flexible in the sitting posture than in the standing posture. This may have reduced the relative motions between lumbar vertebrae and both the supporting vibrating surface and the other vertebrae in the sitting posture. The characteristics of the vibration transmitted to the pelvis may have differed in the two postures due to different transmission paths. Increased forward rotation of the pelvis in the standing posture may have caused the differences in responses of the pelvis and the lower spine that were observed between the two postures.

  11. Transfer of dynamic learning across postures.

    PubMed

    Ahmed, Alaa A; Wolpert, Daniel M

    2009-11-01

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

  12. Transfer of Dynamic Learning Across Postures

    PubMed Central

    Wolpert, Daniel M.

    2009-01-01

    When learning a difficult motor task, we often decompose the task so that the control of individual body segments is practiced in isolation. But on re-composition, the combined movements can result in novel and possibly complex internal forces between the body segments that were not experienced (or did not need to be compensated for) during isolated practice. Here we investigate whether dynamics learned in isolation by one part of the body can be used by other parts of the body to immediately predict and compensate for novel forces between body segments. Subjects reached to targets while holding the handle of a robotic, force-generating manipulandum. One group of subjects was initially exposed to the novel robot dynamics while seated and was then tested in a standing position. A second group was tested in the reverse order: standing then sitting. Both groups adapted their arm dynamics to the novel environment, and this movement learning transferred between seated and standing postures and vice versa. Both groups also generated anticipatory postural adjustments when standing and exposed to the force field for several trials. In the group that had learned the dynamics while seated, the appropriate postural adjustments were observed on the very first reach on standing. These results suggest that the CNS can immediately anticipate the effect of learned movement dynamics on a novel whole-body posture. The results support the existence of separate mappings for posture and movement, which encode similar dynamics but can be adapted independently. PMID:19710374

  13. Postural behavior in children born preterm.

    PubMed

    Fallang, Bjørg; Hadders-Algra, Mijna

    2005-01-01

    The present paper presents clinical and neurophysiological data of postural behavior in preterm children without CP. Clinical follow-up studies of preterm infants until toddler and school age have reported that low-risk preterm infants may have atypical postural behavior in terms of reduced amount of rotation during crawling, delayed dynamic balance, delayed onset of and a poor quality of early walking behavior. At school age, dysfunctions such as problems in standing on one leg and poor hopping are reported. Neurophysiological data of postural control at early age indicated the presence of a dysfunction in the capacity to modulate postural activity, and the postural activity has been characterized by temporal disorganization of EMG responses. Postural responses to goal-directed reaching in supine lying have been recorded and analyzed in terms of the total body center of pressure. In this study, preterm infants show less mobile postural behavior compared with full-term infants. In infancy, the less mobile postural behavior seemed to be adequate as it was related to better goal-directed reaching quality, but the results indicated that the relatively immobile postural behavior during reaching in early age was related to less favorable neuromotor behavior in school-age.

  14. Should Ballet Dancers Vary Postures and Under-Foot Surfaces When Practicing Postural Balance?

    PubMed

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

    2017-03-24

    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 been adequately addressed. The main aim of the present 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. Thirty-six male and female young professional ballet dancers (aged 14-19) completed static and dynamic balance testing, measured by head and lumbar accelerometers, while standing on one leg in the turn-out 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; 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<.05); and, Static PB in the "relaxed" posture was significantly better than PB in all the other five conditions tested. Dynamic PB was significantly better while standing in ballet shoes with textured insoles and when standing on a spiky mat, compared with all other conditions (p<.05). The practical implications derived from the present study are that both male and female dancers should try to be "relaxed" in their postural muscles when practicing a "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.

  15. Use of an allostatic neurotechnology by adolescents with postural orthostatic tachycardia syndrome (POTS) is associated with improvements in heart rate variability and changes in temporal lobe electrical activity.

    PubMed

    Fortunato, John E; Tegeler, Catherine L; Gerdes, Lee; Lee, Sung W; Pajewski, Nicholas M; Franco, Meghan E; Cook, Jared F; Shaltout, Hossam A; Tegeler, Charles H

    2016-03-01

    Autonomic dysregulation and heterogeneous symptoms characterize postural orthostatic tachycardia syndrome (POTS). This study evaluated the effect of high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM(®)), a noninvasive, allostatic neurotechnology for relaxation and auto-calibration of neural oscillations, on heart rate variability, brain asymmetry, and autonomic symptoms, in adolescents with POTS. Seven subjects with POTS (three males, ages 15-18) underwent a median of 14 (10-16) HIRREM sessions over 13 (8-17) days. Autonomic function was assessed from 10-min continuous heart rate and blood pressure recordings, pre- and post-HIRREM. One-minute epochs of temporal high-frequency (23-36 Hz) brain electrical activity data (T3 and T4, eyes closed) were analyzed from baseline HIRREM assessment and subsequent sessions. Subjects rated autonomic symptoms before and after HIRREM. Four of seven were on fludrocortisone, which was stopped before or during their sessions. Heart rate variability in the time domain (standard deviation of the beat-to-beat interval) increased post-HIRREM (mean increase 51%, range 10-143, p = 0.03), as did baroreflex sensitivity (mean increase in high-frequency alpha 65%, range -6 to 180, p = 0.05). Baseline temporal electrical asymmetry negatively correlated with change in asymmetry from assessment to the final HIRREM session (p = 0.01). Summed high-frequency amplitudes at left and right temporal lobes decreased a median of 3.8 μV (p = 0.02). There was a trend for improvements in self-reported symptoms related to the autonomic nervous system. Use of HIRREM was associated with reduced sympathetic bias in autonomic cardiovascular regulation, greater symmetry and reduced amplitudes in temporal lobe high-frequency electrical activity, and a trend for reduced autonomic symptoms. Data suggest the potential for allostatic neurotechnology to facilitate increased flexibility in autonomic cardiovascular regulation, possibly

  16. The effects of backpack load and carrying method on the balance of adolescent idiopathic scoliosis subjects.

    PubMed

    Sahli, Sonia; Rebai, Haithem; Ghroubi, Sameh; Yahia, Abdelmonem; Guermazi, Mohamed; Elleuch, Mohamed Habib

    2013-12-01

    Concerns have been raised about the effect of backpack carrying on adolescent balance. For adolescent idiopathic scoliosis (AIS) subjects, the effect of backpack carrying method on their balance has not been determined. Our aim is to examine the effects of backpack load and carrying method on AIS subjects' balance. Paired sample matched for age and sex. Twelve healthy adolescents matched for age and sex with 14 adolescents with mild AIS participated in this study. A test battery including clinical examination, radiological assessment, and stabilometric measurements of the postural sways in the upright standing posture were conducted. Center of pressure excursions of our subjects were recorded with a stabilometric platform during the upright standing posture without a backpack and while carrying a backpack symmetrically and asymmetrically on each shoulder. For each carrying method, the backpack is loaded at 10% and 15% of body weight (BW). Our results indicated that postural sways increased with increasing backpack load. These postural sways were observed when normal adolescents carried a backpack loaded with 15% BW load, whereas, for age- and sex-matched AIS subjects, these postural responses were observed for the 10% BW load. The symmetrical backpack carrying induced better balance compared with the asymmetrical one. Asymmetrical carrying on the convex side of the scoliotic curve affects AIS subjects' balance more than carrying it on the concave side. Load carriage of 10% BW seems to alter AIS subjects' balance. Asymmetrical carrying should be avoided especially on the convex side of the scoliotic curve because it causes balance impairments that may increase spinal pain. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Impaired Synergic Control of Posture in Parkinson’s Patients without Postural Instability

    PubMed Central

    Falaki, Ali; Huang, Xuemei; Lewis, Mechelle M.; Latash, Mark L.

    2015-01-01

    Background Postural instability is one of most disabling motor symptoms in Parkinson’s disease. Indices of multi-muscle synergies are new measurements of movement and postural stability. Objectives Multi-muscle synergies stabilizing vertical posture were studied in Parkinson’s disease patients without clinical symptoms of postural instability (Hoehn-Yahr- ≤ II) and age-matched controls. We tested the hypothesis that both synergy indices during quiet standing and synergy adjustments to self-triggered postural perturbations would be reduced in patients. Methods Eleven Parkinson’s disease patients and 11 controls performed whole-body tasks while standing. Surface electromyography was used to quantify synergy indices stabilizing center of pressure shifts in the anterior-posterior direction during a load-release task. Results Parkinson’s disease patients showed a significantly lower percentage of variance in the muscle activation space accounted for by the first four principal components, significantly reduced synergy indices during steady state, and significantly reduced anticipatory synergy adjustments (a drop in the synergy index prior to the self-triggered unloading). Conclusions The study demonstrates for the first time that impaired synergic control in Parkinson’s disease can be quantified in postural tasks, even in patients without clinical manifestations of postural instability. Synergy measurements may provide a biomarker sensitive for early problems with postural stability in Parkinson’s disease. PMID:27004660

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

    PubMed

    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

  19. Static Postural Stability Is Normal in Dyslexic Children.

    ERIC Educational Resources Information Center

    Brown, Brian; And Others

    1985-01-01

    An experiment on 15 dyslexic and 23 carefully matched control subjects (10- to 12-year-old males), examining their ability to maintain standing posture with eyes open and closed and with standard and tandem foot placement, revealed no differences under any condition tested and no differences in use of visual information to maintain their posture.…

  20. Static Postural Stability Is Normal in Dyslexic Children.

    ERIC Educational Resources Information Center

    Brown, Brian; And Others

    1985-01-01

    An experiment on 15 dyslexic and 23 carefully matched control subjects (10- to 12-year-old males), examining their ability to maintain standing posture with eyes open and closed and with standard and tandem foot placement, revealed no differences under any condition tested and no differences in use of visual information to maintain their posture.…

  1. THE ELEMENTARY SCHOOL CHILD AND HIS POSTURE PATTERNS.

    ERIC Educational Resources Information Center

    DAVIES, EVELYN A.

    A CHILD'S POSTURE PATTERNS MAY LEAD TO AN ADULT'S PHYSICAL HANDICAP. THE MAIN THEME OF THIS BOOK IS TO SERVE AS A GUIDE FOR THE ELEMENTARY TEACHER OR PARENT IN THE DETECTION AND UNDERSTANDING OF DEVIATIONS FROM THE NORMAL POSTURE PATTERNS WHILE THE CHILD IS SITTING, STANDING, OR MOVING ABOUT SO AS TO PREVENT FUTURE HANDICAPPING CONDITIONS.…

  2. Influence of postural threat on postural responses to aversive visual stimuli.

    PubMed

    Lelard, Thierry; Krystkowiak, Pierre; Montalan, Benoît; Longin, Estelle; Bucchioni, Giulia; Ahmaidi, Said; Godefroy, Olivier; Mouras, Harold

    2014-06-01

    Recent research has shown that emotion influences postural control. The objective of the present study was to establish whether or not postural threat influences postural and physiological responses to aversive visual stimuli. In order to investigate the coupling between emotional reactions, motivated behavior and postural responses, we studied the displacement of the subject's center of pressure (COP) and the changes in electrodermal activity (EDA), heart rate (HR) and postural muscle activation. Thirty-two participants (15 males, 17 females; mean ± SD age: 21.4 ± 2.3) viewed affective and neutral pictures while standing still on a force platform in the presence or absence of postural threat. The HR and EDA data revealed that the emotional state varied as a function of the postural condition. The mean displacement in the anteroposterior (AP) axis was more rearwards in response to aversive stimuli that in response to neutral stimuli, in both the absence of postural threat (-0.65 mm and +0.90 mm for aversive and neutral stimuli, respectively) and the presence of postural threat (-0.00 mm vs. +0.89 mm, respectively). An aversive stimulus was associated with a shorter AP COP sway path than a neutral stimulus in the presence of a postural threat (167.26 mm vs. 174.66 mm for aversive and neutral stimuli, respectively) but not in the latter's absence (155.85 mm vs. 154.48 mm, respectively). Our results evidenced withdrawal behavior in response to an aversive stimulus (relative to a neutral stimulus) in the absence of postural threat. Withdrawal behavior was attenuated (but nevertheless active) in the presence of a postural threat. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Mobility as the Purpose of Postural Control

    PubMed Central

    Le Mouel, Charlotte; Brette, Romain

    2017-01-01

    Counteracting the destabilizing force of gravity is usually considered to be the main purpose of postural control. However, from the consideration of the mechanical requirements for movement, we argue that posture is adjusted in view of providing impetus for movement. Thus, we show that the posture that is usually adopted in quiet standing in fact allows torque for potential movement. Moreover, when performing a movement—either voluntarily or in response to an external perturbation—we show that the postural adjustments are organized both spatially and temporally so as to provide the required torque for the movement. Thus, when movement is performed skillfully, the force of gravity is not counteracted but actually used to provide impetus to movement. This ability to move one's weight so as to exploit the torque of gravity seems to be dependent on development and skill learning, and is impaired in aging. PMID:28798679

  4. Determining postural stability

    NASA Technical Reports Server (NTRS)

    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.

  5. Posture in otoneurology. Volume I.

    PubMed

    Norré, M E

    1990-01-01

    In this study, posture is studied in the context of neuro-otological problems. In the several chapters, postural elements, postural influence upon balance aspects as well as postural components of the balance function in normal and pathological conditions are emphasized. Two main applications are put forward: rehabilitation by postural treatment techniques (REHAB) and examination techniques for the vestibulospinal aspects (posturography--PG). I. Balance function Balance is provided by automatic reflexes for stabilization of the visual field (vestibulo-ocular reflex--VOR) and for a correct posture, erect standing (vestibulo-spinal reflex--VSR) and head position (vestibulo-collic reflex--VCR). The fundamental characteristics of these reflexes are described, especially of those related to posture. The reflexes are elaborated on the basis of sensory inputs that inform about changed relations to space and environment, provided by visual, vestibular and proprioceptive systems. The sensory signals are further processed by the centers to adequate reflexes and to some extent to a conscious awareness. II. Dysfunction and adaptation Dysfunction in the balance mechanisms leads to erroneous reflexes, but most importantly to frightening sensations of vertigo. The peripheral disturbances produce a sensory mismatch which is the primum movens of vertigo. Built-in adaptive mechanisms cope with this disturbance and restore global balance function. The mechanisms involved have been studied as vestibular compensation and habituation, VOR-reflex plasticity and sensory "substitutive" compensation. The mechanisms are set into action by the dysfunctional situation and constitute an error-controlled process. Emphasis is laid upon the items related to rehabilitation treatment and posturography. A survey of clinical entities of vestibular peripheral dysfunction is included. III. Examination techniques The logical approach to the patient with vertigo consists in an analysis of the complaints

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

    PubMed

    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.

  7. Postural control during visual and kinesthetic motor imagery.

    PubMed

    Grangeon, M; Guillot, A; Collet, C

    2011-03-01

    Despite the accumulating evidence supporting an interaction between cognitive functions and postural control, little is known about the selective impact of the mental representation of an action, i.e., motor imagery (MI) on postural control. As postural oscillations are reduced during a cognitive task of backward silent counting, a greater stability is also expected during MI compared to a no-task condition (standing). Twenty participants took part in this experiment, which aimed at providing evidence that MI may improve postural stability. They were requested to mentally imagine a movement while standing on a force-plate. Results showed a decrease in both path length and postural sway variability on the anterior-posterior and lateral axes during all dual-task sessions, as compared to the motionless condition. These postural adjustments might result from both central and peripheral processes, and/or increased muscle stiffness. Conversely, postural oscillation amplitude increased on the vertical axis during MI of three vertical jumps, hence suggesting that postural regulations remain task-related during MI. Finally, our data showed that kinesthetic and visual imagery differentially impacted the postural regulation.

  8. Psychometric evaluation of the Posture and Postural Ability Scale for children with cerebral palsy.

    PubMed

    Rodby-Bousquet, Elisabet; Persson-Bunke, Måns; Czuba, Tomasz

    2016-07-01

    To evaluate construct validity, internal consistency and inter-rater reliability of the Posture and Postural Ability Scale for children with cerebral palsy. Evaluation of psychometric properties. Five child rehabilitation centres in the south of Sweden, in November 2013 to March 2014. A total of 29 children with cerebral palsy (15 boys, 14 girls), 6-16 years old, classified at Gross Motor Function Classification System (GMFCS) levels II (n = 10), III (n = 7), IV (n = 6) and V (n = 6). Three independent raters (two physiotherapists and one orthopaedic surgeon) assessed posture and postural ability of all children in supine, prone, sitting and standing positions, according to the Posture and Postural Ability Scale. Construct validity was evaluated based on averaged values for the raters relative to known-groups in terms of GMFCS levels. Internal consistency was analysed with Cronbach's alpha and corrected Item-Total correlation. Inter-rater reliability was calculated using weighted kappa scores. The Posture and Postural Ability Scale showed construct validity and median values differed between GMFCS levels (p < 0.01). There was a good internal consistency (alpha = 0.95-0.96; item-total correlation = 0.55-0.91), and an excellent inter-rater reliability (kappa score = 0.77-0.99). The Posture and Postural Ability Scale shows high psychometric properties for children with cerebral palsy, as previously seen when evaluated for adults. It enables detection of postural deficits and asymmetries indicating potential need for support and where it needs to be applied. © The Author(s) 2015.

  9. Postural education and behavior among students in a city in southern Brazil: student postural education and behavior

    PubMed Central

    Fonseca, Cíntia Detsch; Cardoso dos Santos, Antônio; Candotti, Cláudia Tarragô; Noll, Matias; Luz, Anna Maria Hecker; Corso, Carlos Otávio

    2015-01-01

    [Purpose] The aim of the present study was to assess the knowledge of the spine and posture among adolescent female students and to determine if they had access to postural education in or outside school. [Subjects and Methods] This was an epidemiological survey of a representative sample of 495 female students aged 14 to 18 years attending a regular secondary school in São Leopoldo, RS, Brazil. Data were collected through a questionnaire. [Results] The results showed that 16.8% of teens did not know what a spine was, 8.3% had no knowledge of posture, and 61% reported receiving no posture education. Posture awareness was associated only with posture while using a computer, while having postural education class was not associated with any postural behavior. [Conclusion] The results showed that, although most students are familiar with the spine and posture, a sizable group is not, and over half had no postural education. These findings suggest that inclusion of postural education programs in schools should be encouraged in order to promote health and prevent diseases related to the spine. PMID:26504322

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

    PubMed

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

    2015-01-01

    Spinal posture and mobility are significant for protecting spine. The aim was to compare effects of different postural training interventions on spinal posture and mobility. Ninety-six university students (ages: 18–25 years) were allocated into Electrical Stimulation (ES) (n = 24), Exercise (n = 24), Biofeedback Posture Trainer (Backtone) (n = 24), and Postural Education (n = 24, Controls) groups. All the groups got postural education. The interventions were carried out 3 days a week for 8 weeks. Spinal Mouse device (Idiag, Fehraltorf, Switzerland) was used to detect thoracic and lumbar curvatures and mobility (degrees) in standing and sitting positions. Paired Student’s t-test, one-way ANOVA, and pairwise post-hoc tests were used. ES decreased thoracic curvature, the exercise decreased thoracic and lumbar curvature and increased thoracic mobility in standing position between pre-post training (p < 0.05). Exercise and Backtone improved thoracic curvature in sitting (p <0.05). In Exercise Group, thoracic curvature decreased compared to Backtone and Education Groups, and thoracic mobility increased compared to all groups (p < 0.05). The exercise was effective and superior in improving thoracic and lumbar curves, and mobility among university students. ES decreased thoracic curve. Biofeedback posture trainer improved sitting posture. A prospective randomized controlled trial, Level 1.

  11. Posture Training for Special Needs Students.

    ERIC Educational Resources Information Center

    James, Terrance N.; And Others

    1986-01-01

    Educable mentally handicapped adolescents with and without additional health problems (N=24) participated in a three-month fitness intervention program. Pre- and post-measures revealed a high incidence of poor posture in both groups. Related topics discussed include subsequent biomechanical interventions, subjective symptomatology, and the need…

  12. Standing between Two Worlds in Harlem: A Developmental Psychopathology Perspective of Perinatally Acquired Human Immunodeficiency Virus and Adolescence

    ERIC Educational Resources Information Center

    Kang, Ezer; Mellins, Claude Ann; Ng, Warren Yiu Kee; Robinson, Lisa-Gaye; Abrams, Elaine J.

    2008-01-01

    Perinatal HIV infection in the US continues to evolve from a fatal pediatric illness to a chronic medical condition of childhood and adolescence. Although navigating this period is influenced by multi-leveled deprivations commonly experienced by low-income minority families, HIV alters the timing and experience of developmental milestones for many…

  13. Standing between Two Worlds in Harlem: A Developmental Psychopathology Perspective of Perinatally Acquired Human Immunodeficiency Virus and Adolescence

    ERIC Educational Resources Information Center

    Kang, Ezer; Mellins, Claude Ann; Ng, Warren Yiu Kee; Robinson, Lisa-Gaye; Abrams, Elaine J.

    2008-01-01

    Perinatal HIV infection in the US continues to evolve from a fatal pediatric illness to a chronic medical condition of childhood and adolescence. Although navigating this period is influenced by multi-leveled deprivations commonly experienced by low-income minority families, HIV alters the timing and experience of developmental milestones for many…

  14. Postural steadiness and ankle force variability in peripheral neuropathy

    PubMed Central

    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

  15. The reliability and validity of the Saliba Postural Classification System.

    PubMed

    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.

  16. Fear of falling and postural control in Parkinson's disease.

    PubMed

    Adkin, Allan L; Frank, James S; Jog, Mandar S

    2003-05-01

    This study investigated the relationship between fear of falling (FOF) and qualitative and quantitative postural control in Parkinson's disease (PD). Fifty-eight nondemented PD patients were studied along with age-matched healthy controls. The degree of FOF was estimated using the Activities-specific Balance Confidence scale. Qualitative postural control was evaluated using a component of the Unified Parkinson Disease Rating Scale. Postural control was quantified, using centre of pressure measures obtained from a force plate, for eight standing balance tests of different challenges. The results showed that FOF was more evident for PD patients when compared with healthy individuals of similar age. Furthermore, FOF was significantly associated with a qualitative estimate of postural control in PD; individuals with PD who had a greater degree of posture impairment reported greater FOF. The results also showed that an estimate of FOF may help to explain quantitative postural instability in PD. FOF, when coupled with a qualitative estimate of postural control, was able to explain a greater amount of variation in quantitative balance performance for five of the eight balance tests. When considered independently, the qualitative measure of postural control, in general, could not well predict quantitative balance performance. The greater degree of FOF and its possible association with altered postural control suggests that FOF should be considered as an important, independent risk factor in the assessment and treatment of postural instability in patients with PD. Copyright 2003 Movement Disorder Society

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

    PubMed

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

    2014-12-01

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

  18. Axially evoked postural reflexes: influence of task.

    PubMed

    Govender, Sendhil; Dennis, Danielle L; Colebatch, James G

    2015-01-01

    Postural reflexes were recorded in healthy subjects (n = 17) using brief axial accelerations and tap stimuli applied at the vertebra prominens (C7) and manubrium sterni. Short latency (SL) responses were recorded from the soleus, hamstrings and tibialis anterior muscles and expressed as a percentage of the background EMG prior to stimulus onset. In the majority of postural conditions tested, subjects were recorded standing erect and leaning forward with their feet together. The SL response was larger for soleus than for the hamstrings during standing (soleus vs hamstrings; 70.4 vs 28.1%), whereas the opposite occurred during kneeling (25.3 vs 127.3%). Concordant head and trunk accelerations produced larger SL responses than discordant accelerations for soleus and hamstrings, but the evoked excitatory response was independent of head direction and as expected for the direction of truncal acceleration. Postural reflexes for soleus and tibialis anterior were strongly affected by conditions that posed a significant threat to postural stability; stimulation at C7 was associated with significant SL enhancement for soleus during anterior lean while sternal stimulation showed SL enhancement for tibialis anterior during posterior lean. Cutaneous anaesthesia applied over the C7 stimulation site had no significant effect on EMG responses, nor did vision or surface type (rigid or compliant). This study provides further evidence that postural reflexes produced by brief axial accelerations are independent of cutaneous receptors, vestibular afferents and ankle proprioceptors, and demonstrates that postural tasks and truncal orientation significantly affect the evoked response, consistent with a role in stabilising posture.

  19. Development of prolonged standing strain index to quantify risk levels of standing jobs.

    PubMed

    Halim, Isa; Omar, Abdul Rahman

    2012-01-01

    Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.

  20. Postural Control in Man: The Phylogenetic Perspective

    PubMed Central

    Gramsbergen, Albert

    2005-01-01

    Erect posture in man is a recent affordance from an evolutionary perspective. About eight million years ago, the stock from which modern humans derived split off from the ape family, and from around sixty-thousand years ago, modern man developed. Upright gait and manipulations while standing pose intricate cybernetic problems for postural control. The trunk, having an older evolutionary history than the extremities, is innervated by medially descending motor systems and extremity muscles by the more recent, laterally descending systems. Movements obviously require concerted actions from both systems. Research in rats has demonstrated the interdependencies between postural control and the development of fluent walking. Only 15 days after birth, adult-like fluent locomotion emerges and is critically dependent upon postural development. Vesttibular deprivation induces a retardation in postural development and, consequently, a retarded development of adult-like locomotion. The cerebellum obviously has an important role in mutual adjustments in postural control and extremity movements, or, in coupling the phyiogenetic older and newer structures. In the human, the cerebellum develops partly after birth and therefore is vulnerable to adverse perinatal influences. Such vulnerability seems to justify focusing our scientific research efforts onto the development of this structure. PMID:16097476

  1. [Risks of awkward posture].

    PubMed

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

    2010-01-01

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

  2. Postural orthostatic tachycardia syndrome (POTS).

    PubMed

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

    2013-09-16

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

  3. Postural orthostatic tachycardia syndrome (POTS)

    PubMed Central

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

    2013-01-01

    Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous group of conditions characterised by autonomic dysfunction and an exaggerated sympathetic response to assuming an upright position. Up till recently, it was largely under-recognised as a clinical entity. There is now consensus about the definition of POTS as a greater than 30/min heart rate increase on standing from a supine position (greater than 40/min increase in 12–19-year-old patients) or an absolute heart rate of greater than 120/min within 10 min of standing from a supine position and in the absence of hypotension, arrhythmias, sympathomimetic drugs or other conditions that cause tachycardia. We present two cases of POTS, followed by a discussion of its pathogenesis, pathophysiology, epidemiology and management. PMID:24042210

  4. Obesity Impact on the Attentional Cost for Controlling Posture

    PubMed Central

    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

  5. Assessing Somatosensory Utilization during Unipedal Postural Control

    PubMed Central

    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. PMID:28443004

  6. Assessing Somatosensory Utilization during Unipedal Postural Control.

    PubMed

    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.

  7. Clinical evaluation of a new biofeedback standing balance training device.

    PubMed

    Lee, M Y; Wong, M K; Tang, F T

    1996-01-01

    For patients with neurological damage of the central nervous system, such as that due to cerebrovascular accident (CVA), standing balance training is a critical therapeutic procedure to be undertaken before walking and self-care training. The identification and characterization of neurological disorder in postural steadiness will enhance our understanding of the postural control system, and help to identify patients at risk of falls in the CVA population. This paper discusses the design and clinical evaluation of a new biofeedback training device for static (postural steadiness) performance of the standing balance system. The device includes a height adjustable standing table, an instrumented force sensing platform, an on-line weight bearing audio/visual biofeedback system, a postural correction mirror, and a belt suspension system for the upper extremities. A quantitative evaluation protocol of bilateral asymmetries in weight distribution and postural sway to characterize standing balance with the force sensing platform is discussed. Finally, the clinical evaluation results of sixty patients with hemiplegia from acute stroke for a period of four weeks are discussed. With this economic standing training device, the static standing steadiness can be trained effectively through weight bearing biofeedback and a postural correction mirror in the clinical and home caring environments.

  8. Postural sway during retinal image stabilisation.

    PubMed

    Rushton, D N; Brandt, T; Paulus, W; Krafczyk, S

    1989-03-01

    Posturographic measurements using a piezoelectric platform were made in normal subjects while wearing a combination of spectacle and contact lens providing partial stabilisation of the retinal image (RIS). The amount of postural sway seen while wearing the device at rest is intermediate between the "normal vision" and "eyes closed" conditions, and increases with increasing amounts of RIS. However, when large active head-and-eye movements are performed, postural sway is dramatically increased when using RIS, and is then worse than while performing the same task in the "eyes closed" condition. It is concluded that patients who use the partial-RIS device for the treatment of severe oscillopsia may benefit only when performing tasks in which the head is relatively still, such as reading, writing or watching TV. It is also proposed that the partial-RIS device can serve as a model in normal free-standing subjects for the postural effects of oculomotor disorders.

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

    PubMed

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

    2014-04-01

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

  10. Barnacle Geese Achieve Significant Energetic Savings by Changing Posture

    PubMed Central

    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. PMID:23071672

  11. Barnacle geese achieve significant energetic savings by changing posture.

    PubMed

    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.

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

    PubMed

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

    2010-06-01

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

  13. Can Smartwatches Replace Smartphones for Posture Tracking?

    PubMed Central

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

    2015-01-01

    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. PMID:26506354

  14. Can smartwatches replace smartphones for posture tracking?

    PubMed

    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.

  15. Multi-joint postural behavior in patients with knee osteoarthritis.

    PubMed

    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.

  16. [Posture and aging. Current fundamental studies and management concepts].

    PubMed

    Mourey, F; Camus, A; Pfitzenmeyer, P

    2000-02-19

    FUNDAMENTAL IMPORTANCE OF POSTURE: In the elderly subject, preservation of posture is fundamental to maintaining functional independence. In recent years, there has been much progress in our understanding of the mechanisms underlying strategies used to control equilibrium in the upright position. Physiological aging, associated with diverse disease states, dangerously alters the postural function, particularly anticipated adjustments which allow an adaptation of posture to movement. CLINICAL ASSESSMENT OF POSTURE: Several tests have been developed to assess posture in the elderly subject, particularly the time it takes to start walking. We selected certain tests which can be used in everyday practice to predict falls: the stance test, the improved Romberg test, the "timed get up and go test", measurement of walking cadence, assessment of balance reactions, sitting-standing and standing-sitting movements and capacity to get up off the floor. PATIENT CARE: Elderly patients with equilibrium disorders can benefit from specific personalized rehabilitation protocols. Different techniques have been developed for multiple afferential stimulation, reprogramming postural strategies, and correcting for deficient motor automatisms.

  17. The influence of sounds on posture control.

    PubMed

    Siedlecka, Bożena; Sobera, Małgorzata; Sikora, Aleksandra; Drzewowska, Izabela

    2015-01-01

    It is still not clear which parameters of sound are the most significant for body reactions and whether the way of sound reception plays a role in body control. The purpose of this study was to determine the influence of frequency, spectrum and loudness of sounds on posture control in healthy women and men. The study subjects were 29 young adults who were submitted to a 60-second standing test in the bipedal stance on the force platform (AMTI). During the tests, 3 sinusoidal sounds with various timing and 2 musical sounds (guitar and piano) of the frequency 225 Hz, 1000 Hz and 4000 Hz were applied through headphones. The centre of pressure (COP) amplitude was registered. The sway area and COP mean velocity were computed. It was found that high frequency sounds contributed to a significant decrease of sway area values. No significant influence of low frequency sounds on posture control was observed. The influence of the sound spectrum (timbre) on posture control is limited; only the crescendo spectrum improves the body stability in the bipedal stance and not the music spectrum as guitar and piano. The loudness of sound, although extremely high, is not the cause of postural control changing in relation to lower loudness. No effect of gender was found in terms of body stability under different sound conditions. Based on the results, it can be argued that, in general, in a bipedal stance in terms of stability high sound frequency improves posture control, whereas sound spectrum and intensity show a limited impact.

  18. Lift performance and lumbar loading in standing and seated lifts.

    PubMed

    Middleton, Kane J; Carstairs, Greg L; Ham, Daniel J

    2016-09-01

    This study investigated the effect of posture on lifting performance. Twenty-three male soldiers lifted a loaded box onto a platform in standing and seated postures to determine their maximum lift capacity and maximum acceptable lift. Lift performance, trunk kinematics, lumbar loads, anthropometric and strength data were recorded. There was a significant main effect for lift effort but not for posture or the interaction. Effect sizes showed that lumbar compression forces did not differ between postures at lift initiation (Standing 5566.2 ± 627.8 N; Seated 5584.0 ± 16.0) but were higher in the standing posture (4045.7 ± 408.3 N) when compared with the seated posture (3655.8 ± 225.7 N) at lift completion. Anterior shear forces were higher in the standing posture at both lift initiation (Standing 519.4 ± 104.4 N; Seated 224.2 ± 9.4 N) and completion (Standing 183.3 ± 62.5 N; Seated 71.0 ± 24.2 N) and may have been a result of increased trunk flexion and a larger horizontal distance of the mass from the L5-S1 joint. Practitioner Summary: Differences between lift performance and lumbar forces in standing and seated lifts are unclear. Using a with-in subjects repeated measures design, we found no difference in lifted mass or lumbar compression force at lift initiation between standing and seated lifts.

  19. Cybersickness without the wobble: Experimental results speak against postural instability theory.

    PubMed

    Dennison, Mark Stephen; D'Zmura, Michael

    2017-01-01

    It has been suggested that postural instability is necessary for cybersickness to occur. Seated and standing subjects used a head-mounted display to view a virtual tunnel that rotated about their line of sight. We found that the offset direction of perceived vertical settings matched the direction of the tunnel's rotation, so replicating earlier findings. Increasing rotation speed caused cybersickness to increase, but had no significant impact on perceived vertical settings. Postural sway during rotation was similar to postural sway during rest. While a minority of subjects exhibited postural sway in response to the onset of tunnel rotation, the majority did not. Furthermore, cybersickness increased with rotation speed similarly for the seated and standing conditions. Finally, subjects with greater levels of cybersickness exhibited less variation in postural sway. These results lead us to conclude that the link between postural instability and cybersickness is a weak one in the present experiment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The neuropathic postural tachycardia syndrome

    NASA Technical Reports Server (NTRS)

    Jacob, G.; Costa, F.; Shannon, J. R.; Robertson, R. M.; Wathen, M.; Stein, M.; Biaggioni, I.; Ertl, A.; Black, B.; Robertson, D.

    2000-01-01

    BACKGROUND: The postural tachycardia syndrome is a common disorder that is characterized by chronic orthostatic symptoms and a dramatic increase in heart rate on standing, but that does not involve orthostatic hypotension. Several lines of evidence indicate that this disorder may result from sympathetic denervation of the legs. METHODS: We measured norepinephrine spillover (the rate of entry of norepinephrine into the venous circulation) in the arms and legs both before and in response to exposure to three stimuli (the cold pressor test, sodium nitroprusside infusion, and tyramine infusion) in 10 patients with the postural tachycardia syndrome and in 8 age- and sex-matched normal subjects. RESULTS: At base line, the mean (+/-SD) plasma norepinephrine concentration in the femoral vein was lower in the patients with the postural tachycardia syndrome than in the normal subjects (135+/-30 vs. 215+/-55 pg per milliliter [0.80+/-0.18 vs. 1.27+/-0.32 nmol per liter], P=0.001). Norepinephrine spillover in the arms increased to a similar extent in the two groups in response to each of the three stimuli, but the increases in the legs were smaller in the patients with the postural tachycardia syndrome than in the normal subjects (0.001+/-0.09 vs. 0.12+/-0.12 ng per minute per deciliter of tissue [0.006+/-0.53 vs. 0.71+/-0.71 nmol per minute per deciliter] with the cold pressor test, P=0.02; 0.02+/-0.07 vs. 0.23+/-0.17 ng per minute per deciliter [0.12+/-0.41 vs. 1.36+/-1.00 nmol per minute per deciliter] with nitroprusside infusion, P=0.01; and 0.008+/-0.09 vs. 0.19+/-0.25 ng per minute per deciliter [0.05+/-0.53 vs. 1.12+/-1.47 nmol per minute per deciliter] with tyramine infusion, P=0.04). CONCLUSIONS: The neuropathic postural tachycardia syndrome results from partial sympathetic denervation, especially in the legs.

  1. The neuropathic postural tachycardia syndrome

    NASA Technical Reports Server (NTRS)

    Jacob, G.; Costa, F.; Shannon, J. R.; Robertson, R. M.; Wathen, M.; Stein, M.; Biaggioni, I.; Ertl, A.; Black, B.; Robertson, D.

    2000-01-01

    BACKGROUND: The postural tachycardia syndrome is a common disorder that is characterized by chronic orthostatic symptoms and a dramatic increase in heart rate on standing, but that does not involve orthostatic hypotension. Several lines of evidence indicate that this disorder may result from sympathetic denervation of the legs. METHODS: We measured norepinephrine spillover (the rate of entry of norepinephrine into the venous circulation) in the arms and legs both before and in response to exposure to three stimuli (the cold pressor test, sodium nitroprusside infusion, and tyramine infusion) in 10 patients with the postural tachycardia syndrome and in 8 age- and sex-matched normal subjects. RESULTS: At base line, the mean (+/-SD) plasma norepinephrine concentration in the femoral vein was lower in the patients with the postural tachycardia syndrome than in the normal subjects (135+/-30 vs. 215+/-55 pg per milliliter [0.80+/-0.18 vs. 1.27+/-0.32 nmol per liter], P=0.001). Norepinephrine spillover in the arms increased to a similar extent in the two groups in response to each of the three stimuli, but the increases in the legs were smaller in the patients with the postural tachycardia syndrome than in the normal subjects (0.001+/-0.09 vs. 0.12+/-0.12 ng per minute per deciliter of tissue [0.006+/-0.53 vs. 0.71+/-0.71 nmol per minute per deciliter] with the cold pressor test, P=0.02; 0.02+/-0.07 vs. 0.23+/-0.17 ng per minute per deciliter [0.12+/-0.41 vs. 1.36+/-1.00 nmol per minute per deciliter] with nitroprusside infusion, P=0.01; and 0.008+/-0.09 vs. 0.19+/-0.25 ng per minute per deciliter [0.05+/-0.53 vs. 1.12+/-1.47 nmol per minute per deciliter] with tyramine infusion, P=0.04). CONCLUSIONS: The neuropathic postural tachycardia syndrome results from partial sympathetic denervation, especially in the legs.

  2. [Pyridostigmine in the treatment of postural orthostatic tachycardia syndrome].

    PubMed

    Can, Ilknur; Tholakanahalli, Venkatakrishna

    2014-09-01

    A 34-year-old female patient was admitted with the complaints of inability to stand upright, palpitations, dizziness, and fatigue in the upright posture for the last one year. She was found to stand upright for less than one minute without symptoms. Tilt table testing showed that, compared to baseline her heart rate increased 55 beats/min in the fifth minute of the test with the symptoms of palpitations, fatigue and sweating without any significant change in her blood pressure. Postural orthostatic tachycardia syndrome was diagnosed, and pyridostigmine treatment was started. Four months after treatment her symptoms were relieved so that she was able to function as a nurse.

  3. Postural responses to unexpected perturbations of balance during reaching

    PubMed Central

    Trivedi, Hari; Leonard, Julia A.; Ting, Lena H.; Stapley, Paul J.

    2014-01-01

    To study the interaction between feedforward and feedback modes of postural control, we investigated postural responses during unexpected perturbations of the support surface that occurred during forward reaching in a standing position. We examined postural responses in lower limb muscles of 9 human subjects. Baseline measures were obtained when subjects executed reaching movements to a target placed in front of them (R condition) and during postural responses to forward and backward support-surface perturbations (no reaching, P condition) during quiet stance. Perturbations were also given at different delays after the onset of reaching movements (RP conditions) as well as with the arm extended in the direction of the target, but not reaching (P/AE condition). Results showed that during perturbations to reaching (RP), the initial automatic postural response, occurring around 100 ms after the onset of perturbations, was relatively unchanged in latency or amplitude compared to control conditions (P and P/AE). However, longer latency postural responses were modulated to aid in the reaching movements during forward perturbations but not during backward perturbations. Our results suggest that the nervous system prioritizes the maintenance of a stable postural base during reaching, and that later components of the postural responses can be modulated to ensure the performance of the voluntary task. PMID:20035321

  4. Antisaccades in Parkinson disease: A new marker of postural control?

    PubMed

    Ewenczyk, Claire; Mesmoudi, Salma; Gallea, Cécile; Welter, Marie-Laure; Gaymard, Bertrand; Demain, Adèle; Yahia Cherif, Lydia; Degos, Bertrand; Benali, Habib; Pouget, Pierre; Poupon, Cyril; Lehericy, Stéphane; Rivaud-Péchoux, Sophie; Vidailhet, Marie

    2017-02-28

    To describe the relation between gaze and posture/gait control in Parkinson disease (PD) and to determine the role of the mesencephalic locomotor region (MLR) and cortex-MLR connection in saccadic behavior because this structure is a major area involved in both gait/postural control and gaze control networks. We recruited 30 patients with PD with or without altered postural control and 25 age-matched healthy controls (HCs). We assessed gait, balance, and neuropsychological status and separately recorded gait initiation and eye movements (visually guided saccades and volitional antisaccades). We identified correlations between the clinical and physiologic parameters that best characterized patients with postural instability. We measured resting-state functional connectivity in 2 pathways involving the frontal oculomotor cortices and the MLR and sought correlations with saccadic behavior. Patients with PD with postural instability showed altered antisaccade latencies that correlated with the stand-walk-sit time (r = 0.78, p < 0.001) and the duration of anticipatory postural adjustments before gait initiation (r = 0.61, p = 0.001). Functional connectivity between the pedunculopontine nucleus (PPN) and the frontal eye field correlated with antisaccade latency in the HCs (r = -0.54, p = 0.02) but not in patients with PD. In PD, impairment of antisaccade latencies, a simple and robust parameter, may be an indirect marker correlated with impaired release of anticipatory postural program. PPN alterations may account for both antisaccade and postural impairments. © 2017 American Academy of Neurology.

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

    PubMed

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

    2015-11-01

    Eye movements affect postural stability in children. The present study focuses on the effect of different types of eye movements on postural stability in healthy children. Both eye movements and postural stability have been recorded in 51 healthy children from 6.3 to 15.5 years old. Eye movements were recorded binocularly with a video oculography (MobilEBT(®)), and postural stability was measured while child was standing on a force platform (TechnoConcept(®)). Children performed three oculomotor tasks: saccades, pursuits and reading a text silently. We measured the number of saccades made in the three oculomotor tasks, the number of words read, and the surface area, the length and mean velocity of the center of pressure (CoP). According to previous studies, postural control improves with age until 10-12 years. Saccades toward a target as well as during a reading task reduce significantly the CoP displacement and its velocity, while during pursuit eye movements all children increase postural parameters (i.e., the surface area, the length and mean velocity of the CoP). These results suggest the presence of an interaction between the oculomotor control and the postural system. Visual attention to perform saccades (to stationary targets or to words) influences postural stability more than the frequency of saccade triggering does.

  6. Take a Stand for Standing

    ERIC Educational Resources Information Center

    Labandz, Stephenie

    2010-01-01

    As a school-based physical therapist, the author sees children with a wide variety of diagnoses affecting their mobility and motor function. Supported standing is an important part of the routines of those who are unable to stand independently due to issues affecting the neuromuscular system. Being eye-to-eye with their peers and interacting with…

  7. Take a Stand for Standing

    ERIC Educational Resources Information Center

    Labandz, Stephenie

    2010-01-01

    As a school-based physical therapist, the author sees children with a wide variety of diagnoses affecting their mobility and motor function. Supported standing is an important part of the routines of those who are unable to stand independently due to issues affecting the neuromuscular system. Being eye-to-eye with their peers and interacting with…

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

    PubMed Central

    Mitchell, Tim; O'Sullivan, Peter B; Burnett, Angus F; Straker, Leon; Smith, Anne

    2008-01-01

    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 < 0.001). Regional differences in range of motion from reference postures in sitting and standing were evident. BMI accounted for regional differences found in all sitting and some standing measures. LBP was not associated with differences in regional lumbar spine angles or range of motion, with the exception of maximal backward bending range of motion (F = 5.18, p = 0.007). 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. PMID:19014712

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

    PubMed

    Mitchell, Tim; O'Sullivan, Peter B; Burnett, Angus F; Straker, Leon; Smith, Anne

    2008-11-18

    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. 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. 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 < 0.001). Regional differences in range of motion from reference postures in sitting and standing were evident. BMI accounted for regional differences found in all sitting and some standing measures. LBP was not associated with differences in regional lumbar spine angles or range of motion, with the exception of maximal backward bending range of motion (F = 5.18, p = 0.007). 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.

  10. Tai Chi training reduced coupling between respiration and postural control

    PubMed Central

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

    2015-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body’s center-of-mass including those caused by spontaneous respiration. Both aging and disease increase “posturo-respiratory synchronization;” which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86±5yrs) or educational-control program (n=34, 85±6yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

  11. Tai Chi training reduced coupling between respiration and postural control.

    PubMed

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

    2016-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body's center-of-mass including those caused by spontaneous respiration. Both aging and disease increase "posturo-respiratory synchronization;" which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86 ± 5 yrs) or educational-control program (n=34, 85 ± 6 yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

  12. Postural Analysis in Time and Frequency Domains in Patients with Ehlers-Danlos Syndrome

    ERIC Educational Resources Information Center

    Galli, Manuela; Rigoldi, Chiara; Celletti, Claudia; Mainardi, Luca; Tenore, Nunzio; Albertini, Giorgio; Camerota, Filippo

    2011-01-01

    The goal of this work is to analyze postural control in Ehlers-Danlos syndrome (EDS) participants in time and frequency domain. This study considered a pathological group composed by 22 EDS participants performing a postural test consisting in maintaining standing position over a force platform for 30 s in two conditions: open eyes (OE) and closed…

  13. Postural Analysis in Time and Frequency Domains in Patients with Ehlers-Danlos Syndrome

    ERIC Educational Resources Information Center

    Galli, Manuela; Rigoldi, Chiara; Celletti, Claudia; Mainardi, Luca; Tenore, Nunzio; Albertini, Giorgio; Camerota, Filippo

    2011-01-01

    The goal of this work is to analyze postural control in Ehlers-Danlos syndrome (EDS) participants in time and frequency domain. This study considered a pathological group composed by 22 EDS participants performing a postural test consisting in maintaining standing position over a force platform for 30 s in two conditions: open eyes (OE) and closed…

  14. (De)stabilization of Required and Spontaneous Postural Dynamics with Learning

    ERIC Educational Resources Information Center

    Faugloire, Elise; Bardy, Benoit G.; Stoffregen, Thomas A.

    2009-01-01

    The present research examined how learning a new ankle-hip coordination influenced the preexisting postural repertoire. Standing participants learned a new ankle-hip coordination mode (relative phase of 90[degrees]). Before and after practice, postural patterns were evaluated in two different tasks. In the required task, specific ankle-hip…

  15. (De)stabilization of Required and Spontaneous Postural Dynamics with Learning

    ERIC Educational Resources Information Center

    Faugloire, Elise; Bardy, Benoit G.; Stoffregen, Thomas A.

    2009-01-01

    The present research examined how learning a new ankle-hip coordination influenced the preexisting postural repertoire. Standing participants learned a new ankle-hip coordination mode (relative phase of 90[degrees]). Before and after practice, postural patterns were evaluated in two different tasks. In the required task, specific ankle-hip…

  16. The relationship between dynamic balancing ability and posture-related modulation of the soleus H-reflex.

    PubMed

    Kawaishi, Yu; Domen, Kazuhisa

    2016-02-01

    Soleus H-reflex reveals down modulation with increased postural difficulty. Role of this posture-related reflex modulation is thought to shift movement control toward higher motor centers in order to facilitate more precise postural control. Present study hypothesized that the ability to modulate H-reflex is related to one's ability to dynamically balance while in an unstable posture. This study examined the relationship between dynamic balancing ability and soleus H-reflex posture-related modulation. Thirty healthy adults participated. The soleus maximal H-reflex (Hmax), motor response (Mmax), and background EMG activity (bEMG) were obtained during three postural conditions: prone, open-legged standing, and closed-legged standing. Hmax/Mmax ratios were normalized via the corresponding bEMG in order to remove the effects of background muscle activity from the obtained H-reflex. Reflex modulation was calculated as the ratio of the normalized Hmax/Mmax ratios in one postural condition to another posture in a more difficult condition. Dynamic balancing ability was assessed by testing stability while standing on a wobble board. A significant negative correlation was observed between balancing scores and reflex modulation from open-legged standing to closed-legged standing. This suggests that the ability to modulate monosynaptic stretch reflex excitability in response to a changing posture is a significant factor for dynamic balancing. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Mechanical effort predicts the selection of ankle over hip strategies in nonstepping postural responses.

    PubMed

    Afschrift, Maarten; Jonkers, Ilse; De Schutter, Joris; De Groote, Friedl

    2016-10-01

    Experimental studies have shown that a continuum of ankle and hip strategies is used to restore posture following an external perturbation. Postural responses can be modeled by feedback control with feedback gains that optimize a specific objective. On the one hand, feedback gains that minimize effort have been used to predict muscle activity during perturbed standing. On the other hand, hip and ankle strategies have been predicted by minimizing postural instability and deviation from upright posture. It remains unclear, however, whether and how effort minimization influences the selection of a specific postural response. We hypothesize that the relative importance of minimizing mechanical work vs. postural instability influences the strategy used to restore upright posture. This hypothesis was investigated based on experiments and predictive simulations of the postural response following a backward support surface translation. Peak hip flexion angle was significantly correlated with three experimentally determined measures of effort, i.e., mechanical work, mean muscle activity and metabolic energy. Furthermore, a continuum of ankle and hip strategies was predicted in simulation when changing the relative importance of minimizing mechanical work and postural instability, with increased weighting of mechanical work resulting in an ankle strategy. In conclusion, the combination of experimental measurements and predictive simulations of the postural response to a backward support surface translation showed that the trade-off between effort and postural instability minimization can explain the selection of a specific postural response in the continuum of potential ankle and hip strategies. Copyright © 2016 the American Physiological Society.

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

    PubMed

    Huntley, Andrew H; Zettel, John L

    2015-04-10

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

  19. Movement of the lumbar spine is critical for maintenance of postural recovery following support surface perturbation.

    PubMed

    Mok, Nicola W; Hodges, Paul W

    2013-11-01

    Repeated measures design. This study examined recovery of postural equilibrium (centre of pressure (COP) excursion, time to recover balance, and the number of postural adjustments) following unexpected support surface perturbation in healthy participants with and without a rigid lumbar corset to reduce lumbar motion. Lumbar spine movement is thought to aid postural stability, especially when a "hip" (lumbopelvic) strategy is required, such as in response to large and fast perturbations. Delayed onset of lumbar spine movement in association with prolonged postural recovery in chronic low back pain implies reduced spinal motion could underpin balance deficits in this group. However, other explanations such as poor proprioception cannot be excluded, and the relationship between lumbar movement and postural stability remains unclear. We hypothesized restricted lumbar spine movement would impair control of postural recovery following support surface perturbation. Participants regained postural stability following unexpected support surface perturbations in different directions (forward and backward), with different amplitudes (small, medium, and large), with and without restriction of spine motion by a hard lumbar corset. Although the latency of the postural adjustment was unaffected by the corset, the quality of postural recovery was compromised (increased COP range, time taken for postural recovery, and number of postural adjustments) during recovery, especially in response to large perturbation. Restriction of lumbar spine movement adversely affects postural recovery. The results suggest movement of the lumbar spine, although small in amplitude, is critical for efficient recovery of standing balance.

  20. Social Postural Coordination

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  1. Social Postural Coordination

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  2. Postural dependence of human locomotion during gait initiation

    PubMed Central

    Mille, Marie-Laure; Simoneau, Martin

    2014-01-01

    The initiation of human walking involves postural motor actions for body orientation and balance stabilization that must be effectively integrated with locomotion to allow safe and efficient transport. Our ability to coordinately adapt these functions to environmental or bodily changes through error-based motor learning is essential to effective performance. Predictive compensations for postural perturbations through anticipatory postural adjustments (APAs) that stabilize mediolateral (ML) standing balance normally precede and accompany stepping. The temporal sequencing between these events may involve neural processes that suppress stepping until the expected stability conditions are achieved. If so, then an unexpected perturbation that disrupts the ML APAs should delay locomotion. This study investigated how the central nervous system (CNS) adapts posture and locomotion to perturbations of ML standing balance. Healthy human adults initiated locomotion while a resistance force was applied at the pelvis to perturb posture. In experiment 1, using random perturbations, step onset timing was delayed relative to the APA onset indicating that locomotion was withheld until expected stability conditions occurred. Furthermore, stepping parameters were adapted with the APAs indicating that motor prediction of the consequences of the postural changes likely modified the step motor command. In experiment 2, repetitive postural perturbations induced sustained locomotor aftereffects in some parameters (i.e., step height), immediate but rapidly readapted aftereffects in others, or had no aftereffects. These results indicated both rapid but transient reactive adaptations in the posture and gait assembly and more durable practice-dependent changes suggesting feedforward adaptation of locomotion in response to the prevailing postural conditions. PMID:25231611

  3. Quantifying and Reducing Posture-Dependent Distortion in Ballistocardiogram Measurements.

    PubMed

    Javaid, Abdul Qadir; Wiens, Andrew D; Fesmire, Nathaniel Forrest; Weitnauer, Mary Ann; Inan, Omer T

    2015-09-01

    Ballistocardiography is a noninvasive measurement of the mechanical movement of the body caused by cardiac ejection of blood. Recent studies have demonstrated that ballistocardiogram (BCG) signals can be measured using a modified home weighing scale and used to track changes in myocardial contractility and cardiac output. With this approach, the BCG can potentially be used both for preventive screening and for chronic disease management applications. However, for achieving high signal quality, subjects are required to stand still on the scale in an upright position for the measurement; the effects of intentional (for user comfort) or unintentional (due to user error) modifications in the position or posture of the subject during the measurement have not been investigated in the existing literature. In this study, we quantified the effects of different standing and seated postures on the measured BCG signals, and on the most salient BCG-derived features compared to reference standard measurements (e.g., impedance cardiography). We determined that the standing upright posture led to the least distorted signals as hypothesized, and that the correlation between BCG-derived timing interval features (R-J interval) and the preejection period, PEP (measured using ICG), decreased significantly with impaired posture or sitting position. We further implemented two novel approaches to improve the PEP estimates from other standing and sitting postures, using system identification and improved J-wave detection methods. These approaches can improve the usability of standing BCG measurements in unsupervised settings (i.e., the home), by improving the robustness to nonideal posture, as well as enabling high-quality seated BCG measurements.

  4. Quantifying and Reducing Posture-Dependent Distortion in Ballistocardiogram Measurements

    PubMed Central

    Javaid, Abdul Q.; Wiens, Andrew D.; Fesmire, N. Forrest; Weitnauer, Mary A.; Inan, Omer T.

    2015-01-01

    Ballistocardiography is a non-invasive measurement of the mechanical movement of the body caused by cardiac ejection of blood. Recent studies have demonstrated that ballistocardiogram (BCG) signals can be measured using a modified home weighing scale, and used to track changes in myocardial contractility and cardiac output. With this approach, the BCG can potentially be used both for preventive screening and for chronic disease management applications. However, for achieving high signal quality, subjects are required to stand still on the scale in an upright position for the measurement; the effects of intentional (for user comfort) or unintentional (due to user error) modifications in the position or posture of the subject during the measurement have not been investigated in the existing literature. In this study, we quantified the effects of different standing and seated postures on the measured BCG signals, and on the most salient BCG-derived features compared to reference standard measurements (e.g., impedance cardiography). We determined that the standing upright posture led to the least distorted signals as hypothesized, and that the correlation between BCG-derived timing interval features (R-J interval) and the pre-ejection period, PEP (measured using ICG), decreased significantly with impaired posture or sitting position. We further implemented two novel approaches to improve the PEP estimates from other standing and sitting postures, using system identification and improved J-wave detection methods. These approaches can improve the usability of standing BCG measurements in unsupervised settings (i.e. the home), by improving the robustness to non-ideal posture, as well as enabling high quality seated BCG measurements. PMID:26058064

  5. Reversible postural orthostatic tachycardia syndrome.

    PubMed

    Abdulla, Aza; Rajeevan, Thirumagal

    2015-07-16

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

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

    PubMed

    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.

  7. Integrated postural analysis in children with haemophilia.

    PubMed

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

    2014-03-01

    The maintenance of a correct posture in haemophilic boys might contribute to prevent joint bleeds, chronic pain and dysfunction. This single-centre study was aimed at evaluating whether or not postural alterations are more common in haemophilic than in non-haemophilic boys and whether they are related to the orthopaedic status. Posture and balance were investigated in boys with severe/moderate haemophilia (cases) and in age-matched non-haemophilic peers (controls). Thirty-five cases (89% with haemophilia A: 74% with severe disease) were included in the study and compared with 57 controls. Posture was evaluated on digital pictures of anterior, lateral and posterior views of the habitual standing position. Balance was examined with a portable force platform with eyes open and closed. The trajectory of the total body centre of force (CoF) displacement over the platform was computed by multiple planes obtaining different measures: sway area, velocity, acceleration and body loads. The joint status of cases was assessed with the Haemophilia Joint Health Score. Cases were more disharmonic than controls (52% vs. 26% in controls; P = 0.04), swayed significantly less and more slowly than controls (P < 0.05 for several parameters of CoF displacement) revealing stiffness of the musculoskeletal system. However, they were able to maintain their stance within a similar sway area. Haemophilic boys have more postural disharmonies than non-haemophilic peers, hence a global evaluation of the orthopaedic status should include also balance and posture examination to identify early dysfunction and establish a tailored physical or rehabilitation programme.

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

    PubMed

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

    2017-08-31

    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.

  9. Posture-related modulations in motor cortical excitability of the proximal and distal arm muscles.

    PubMed

    Kantak, Shailesh S; Wittenberg, George F; Liao, Wan-Wen; Magder, Laurence S; Rogers, Mark W; Waller, Sandy McCombe

    2013-01-15

    The effect of postural orientation on the motor corticospinal excitability (MCE) of proximal and distal upper extremity (UE) muscles was investigated. In a crossover design, recruitment curves (RCs), short interval cortical inhibition (SICI) and intracortical facilitation (ICF) of resting anterior deltoid (AD) and first dorsal interosseus (FDI) was assessed in two postures: sitting and standing. Six healthy adults without contraindications to transcranial magnetic stimulation (TMS) participated in the study. TMS was applied over the motor cortical representation of FDI and AD at intensities ranging from 90% to 200% of resting motor threshold (RMT) in increments of 10%. SICI and ICF were assessed for each muscle using a conditioning stimulus (80% RMT) preceding a test stimulus (120% RMT) with an interstimulus interval of 2 ms and 15 ms, respectively. For AD, but not FDI, there was a significant and consistent increase in RC slope during standing compared to sitting. For FDI, there was no difference in ICF and SICI between sitting and standing. However, for AD, while there was no difference in ICF between the two postures, there was a clear trend for SICI to decrease (p=0.06) in standing compared to sitting. These results indicate that postural change from sitting to standing, affects the MCE of proximal but not distal muscles. While this indicates the role of proximal UE muscles in postural control, it also implies that rehabilitation protocols for enhancing proximal arm motor function may be advantaged if administered in a standing posture. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Relationship between static foot posture and foot mobility

    PubMed Central

    2011-01-01

    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. PMID:21244705

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

    PubMed

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

    2017-06-01

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

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  14. Influence of musical groove on postural sway.

    PubMed

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

    2016-03-01

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

  15. Delayed stochastic differential model for quiet standing

    NASA Astrophysics Data System (ADS)

    Yao, W.; Yu, P.; Essex, C.

    2001-02-01

    A physiological quiet standing model, described by a delayed differential equation, subject to a white noise perturbation, is proposed to study the postural control system of human beings. It has been found that the white noise destabilizes the equilibrium state, and inertia accelerates the destabilizing process, and that the position of a person is detected and processed by the person's nervous system with a delay. This paper focuses on the analysis of Hopf bifurcation and its stability in this context. Based on the analytical predictions confirmed by numerical simulations, it has been shown that the posture of a person is controlled in such a way that possible amplitude oscillations are minimized.

  16. Human Balance out of Equilibrium: Nonequilibrium Statistical Mechanics in Posture Control

    NASA Astrophysics Data System (ADS)

    Lauk, Michael; Chow, Carson C.; Pavlik, Ann E.; Collins, James J.

    1998-01-01

    During quiet standing, the human body sways in a stochastic manner. Here we show that the fluctuation-dissipation theorem can be applied to the human postural control system. That is, the dynamic response of the postural system to a weak mechanical perturbation can be predicted from the fluctuations exhibited by the system under quasistatic conditions. We also show that the estimated correlation and response functions can be described by a simple stochastic model consisting of a pinned polymer. These findings suggest that the postural control system utilizes the same control mechanisms under quiet-standing and dynamic conditions.

  17. Postural Control in Children, Teenagers and Adults with Down Syndrome

    ERIC Educational Resources Information Center

    Rigoldi, Chiara; Galli, Manuela; Mainardi, Luca; Crivellini, Marcello; Albertini, Giorgio

    2011-01-01

    The goal of this work was to analyze postural control in Down syndrome (DS) participants considering three different groups composed by children, teenagers and adults with DS. An analysis of the centre of pressure (COP) displacement during standing position was therefore performed for the three groups of subjects. The obtained signal of COP was…

  18. Postural Control in Children, Teenagers and Adults with Down Syndrome

    ERIC Educational Resources Information Center

    Rigoldi, Chiara; Galli, Manuela; Mainardi, Luca; Crivellini, Marcello; Albertini, Giorgio

    2011-01-01

    The goal of this work was to analyze postural control in Down syndrome (DS) participants considering three different groups composed by children, teenagers and adults with DS. An analysis of the centre of pressure (COP) displacement during standing position was therefore performed for the three groups of subjects. The obtained signal of COP was…

  19. Postural neck pain: an investigation of habitual sitting posture, perception of 'good' posture and cervicothoracic kinaesthesia.

    PubMed

    Edmondston, Stephen J; Chan, Hon Yan; Ngai, Gorman Chi Wing; Warren, M Linda R; Williams, Jonathan M; Glennon, Susan; Netto, Kevin

    2007-11-01

    Impairments of cervico-cephalic kinaesthesia and habitual forward head posture have been considered important in the aetiology of postural neck pain, yet these factors have not been specifically examined in a homogeneous clinical population. The objective of this study was to compare the habitual sitting posture (HSP), perception of good posture and postural repositioning error (PRE) of the cervico-thoracic (CT) spine in individuals with postural neck pain, with a matched group of asymptomatic subjects. Twenty-one subjects with postural neck pain and 22 asymptomatic control subjects were recruited into the study. An optical motion analysis system was used to measure the HSP and perceived 'good' sitting posture. PRE was measured over six trials where the subject attempted to replicate their self-selected 'good' posture. There was no difference between the groups in the HSP but significant differences were identified in the perception of 'good' posture. Posture repositioning error was higher for the head posture variables than for CT and shoulder girdle variables in both groups. However, there was no significant difference in posture repositioning error between groups for any of the posture measures. The findings suggest that individuals with postural neck pain may have a different perception of 'good' posture, but no significant difference in HSP or kinaesthetic sensibility compared with matched asymptomatic subjects.

  20. Postural orientation in microgravity depends on straightening up movement performed

    NASA Astrophysics Data System (ADS)

    Vaugoyeau, Marianne; Assaiante, Christine

    2009-08-01

    Whether the vertical body orientation depends on the initial posture and/or the type of straightening up movement is the main question raised in this paper. Another objective was to specify the compensatory role of visual input while adopting an erected posture during microgravity. The final body orientation was analysed in microgravity during parabolic flights. After either (1) straightening up movement from a crouching or (2) a sitting posture, with and without vision. The main results are the following: (1) a vertical erected final posture is correctly achieved after sit to stand movement, whereas all subjects were tilted forward after straightening up from a crouching posture and (2) vision may contribute to correct final posture. These results suggest the existence of a re-weighting of the remaining sensory information, visual information, contact cutaneous cues and proprioceptive information under microgravity condition. We can put forward the alternative hypothesis that the control of body orientation under microgravity condition may also be achieved on the basis of a postural body scheme, that seems to be dependant on the type of movement and/ or the initial position of the whole body.

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

    NASA Astrophysics Data System (ADS)

    Goto, Akifumi; Ishida, Mizuri; Sagawa, Koichi

    2009-12-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Advantages and disadvantages of stiffness instructions when studying postural control.

    PubMed

    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.

  4. Postural orthostatic tachycardia syndrome: a clinical review.

    PubMed

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

    2010-02-01

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

  5. Postural disturbances resulting from unilateral and bilateral diaphragm contractions: a phrenic nerve stimulation study.

    PubMed

    Hamaoui, Alain; Hudson, Anna L; Laviolette, Louis; Nierat, Marie-Cécile; Do, Manh-Cuong; Similowski, Thomas

    2014-10-15

    Thoracoabdominal breathing movements are a complex source of postural disturbance, but there are contradictory reports in the literature with inspiration described as having either a backward or a forward disturbing effect. To elucidate the mechanisms underlying this phenomenon, the present study studied the postural disturbance caused by isolated contractions of the diaphragm. Eight male and four female healthy subjects followed an original paradigm of phrenic nerve stimulation (bilateral and unilateral) and "diaphragmatic" voluntary sniff maneuvers in the seated and standing postures. Center of gravity (CG) acceleration was calculated from force plate recordings, and respiratory kinematics were assessed with thoracic and abdominal sensor belts. CG and respiratory signals revealed that, while seated, bilateral phrenic stimulation and sniff maneuvers consistently produced expansion of the abdomen associated with a forward peak of CG acceleration. In the standing posture, the direction of the CG peak was reversed and always directed backward. Unilateral phrenic stimulation induced an additional medial-lateral acceleration of the CG, directed toward the nonactive side while seated, but in the opposite direction while standing. These results suggest that isolated diaphragmatic contractions produce a constant disturbing pattern for a given posture, but with opposite effects between standing and seated postures. This could be related to the different biomechanical configuration of the body in each posture, corresponding to distinct kinematic patterns of the osteoarticular chain. In addition, the lateral component of the CG acceleration induced by unilateral diaphragm contractions could be clinically relevant in patients with hemidiaphragm paralysis.

  6. [What are the effects of the aging of the neuromuscular system on postural stability?].

    PubMed

    Cattagni, Thomas; Scaglioni, Gil; Cornu, Christophe; Berrut, Gilles; Martin, Alain

    2015-12-01

    Aging is frequently associated with a decreased postural stability, essentially after 60 years, leading to an increased risk of falling. In this article we propose to highlight the influence of the aging of the neuromuscular system on postural stability when standing upright. To maintain balance while standing upright, human needs to control the activity of ankle muscles and particularly the plantar flexors. During the aging process, the performance of these muscles are strongly altered. It is commonly observed large deficits in elderly people with history of falls. Some authors reported an inverse correlation between the amplitude of postural sway and the capacity of force production of ankle muscles suggesting that the assessment of neuromuscular function could be an index of postural stability or even of the falling risk. Finally, enhance the strength of ankle muscles in elderly through physical exercise could be an adequate intervention to improve postural stability and reduce the incidence of falls.

  7. Effect of posture positions on the evaporative resistance and thermal insulation of clothing.

    PubMed

    Wu, Y S; Fan, J T; Yu, W

    2011-03-01

    Evaporative resistance and thermal insulation of clothing are important parameters in the design and engineering of thermal environments and functional clothing. Past work on the measurement of evaporative resistance of clothing was, however, limited to the standing posture with or without body motion. Information on the evaporative resistance of clothing when the wearer is in a sedentary or supine posture and how it is related to that when the wearer is in a standing posture is lacking. This paper presents original data on the effect of postures on the evaporative resistance of clothing, thermal insulation and permeability index, based on the measurements under three postures, viz. standing, sedentary and supine, using the sweating fabric manikin-Walter. Regression models are also established to relate the evaporative resistance and thermal insulation of clothing under sedentary and supine postures to those under the standing posture. The study further shows that the apparent evaporated resistances of standing and sedentary postures measured in the non-isothermal condition are much lower than those in the isothermal condition. The apparent evaporative resistances measured using the mass loss method are generally lower than those measured using the heat loss method due to moisture absorption or condensation within clothing. STATEMENT OF RELEVANCE: The thermal insulation and evaporative resistance values of clothing ensembles under different postures are essential data for the ergonomics design of thermal environments (e.g. indoors or a vehicle's interior environment) and functional clothing. They are also necessary for the prediction of thermal comfort or duration of exposure in different environmental conditions.

  8. GNB3 C825T polymorphism is associated with postural tachycardia syndrome in children.

    PubMed

    Nakao, Ryota; Tanaka, Hidetaka; Takitani, Kimitaka; Kajiura, Mitsugu; Okamoto, Naoyuki; Kanbara, Yukiko; Tamai, Hiroshi

    2012-12-01

    Postural tachycardia syndrome (POTS) is one of the most frequent forms of chronic orthostatic intolerance in children and adolescents. The aim of the present study was to examine the influence of a genetic background on POTS. A total of 96 children and adolescents with orthostatic dysregulation were studied. The polymorphism of the G protein β3 subunit (GNB3) C825T and G protein α subunit (GNAS1) T131C of genes encoding components of the autonomic nervous system were determined and compared with circulatory responses to active standing. In the GNB3 gene C825T polymorphism, the CT and TT genotype had a significant lower supine heart rate and a larger increase of heart rate by standing than the CC, associated with evaluated power of the high-frequency component of heart rate variability. According to the criteria of the Japanese clinical guidelines, 48 children were diagnosed as POTS and 30 were as normal responder with somatoform disorder (SD). In GNB3 C825T polymorphism, the TT genotype was more frequently found in the POTS group (45.8%) than in the SD group (20.0%; P = 0.036) [corrected]. In the GNAS1 T393C, the genotype frequencies for the T393C polymorphisms of GNA1 did not differ significantly between the groups. The gene polymorphisms GNB3 C825T might be a risk factor for POTS through the enhanced vagal withdrawal of the heart in children and adolescents. © 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.

  9. Chest compression with kneeling posture in hospital cardiopulmonary resuscitation: A randomised crossover simulation study.

    PubMed

    Oh, Jaehoon; Chee, Youngjoon; Lim, Taeho; Cho, Youngsuk; Kim, In Young

    2014-12-01

    We suggest an alternative chest compression (CC) in kneeling posture using a 'kneeling stool' on which the performer kneels beside the patient on a bed in-hospital. In kneeling posture, we can maintain high quality cardiopulmonary resuscitation (CPR) without the bed height adjustment, which is necessary and inconvenient in standing posture. This study is a randomised crossover trial with 38 participants working in one ED. The first group knelt on the kneeling stool beside a manikin placed on a bed, whereas the second group stood on a step stool with the manikin at knee level using bed height adjustment. All the participants performed continuous chest compression for 5 min without audio-visual feedback. After that, the posture was changed in each group. The parameters of CC quality (CC depth, rate, accuracy, and incomplete chest recoil), visual analogue scale (VAS) for fatigue and pain, and preference of participants were compared between the two groups. The data of 33 participants in both postures were analysed following exclusion of five participants. In the comparisons overall and per minute between the two postures, the parameters and VAS do not differ significantly (all P > 0.05) except for the median 1st CC rate that was faster in kneeling posture than in standing posture, P = 0.01). Twenty-three performers preferred the kneeling posture. A kneeling posture with a kneeling stool were preferred by participants, which have shown similar results in CC parameters and VAS with a standing posture on a stepstool with bed height adjustment during in-hospital CPR. © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  10. Normative values for the Foot Posture Index

    PubMed Central

    Redmond, Anthony C; Crane, Yvonne Z; Menz, Hylton B

    2008-01-01

    Background The Foot Posture Index (FPI) is a validated method for quantifying standing foot posture, and is being used in a variety of clinical settings. There have however, been no normative data available to date for comparison and reference. This study aimed to establish normative FPI reference values. Methods Studies reporting FPI data were identified by searching online databases. Nine authors contributed anonymised versions of their original datasets comprising 1648 individual observations. The datasets included information relating to centre, age, gender, pathology (if relevant), FPI scores and body mass index (BMI) where available. FPI total scores were transformed to interval logit scores as per the Rasch model and normal ranges were defined. Comparisons between groups employed t-tests or ANOVA models as appropriate and data were explored descriptively and graphically. Results The main analysis based on a normal healthy population (n = 619) confirmed that a slightly pronated foot posture is the normal position at rest (mean back transformed FPI raw score = +4). A 'U' shaped relationship existed for age, with minors and older adults exhibiting significantly higher FPI scores than the general adult population (F = 51.07, p < 0.001). There was no difference between the FPI scores of males and females (2.3 versus 2.5; t = -1.44, p = 0.149). No relationship was found between the FPI and BMI. Systematic differences from the adult normals were confirmed in patients with neurogenic and idiopathic cavus (F = 216.981, p < 0.001), indicating some sensitivity of the instrument to detect a posturally pathological population. Conclusion A set of population norms for children, adults and older people have been derived from a large sample. Foot posture is related to age and the presence of pathology, but not influenced by gender or BMI. The normative values identified may assist in classifying foot type for the purpose of research and clinical decision making. PMID

  11. Functional muscle synergies constrain force production during postural tasks.

    PubMed

    McKay, J Lucas; Ting, Lena H

    2008-01-01

    We recently demonstrated that a set of five functional muscle synergies were sufficient to characterize both hindlimb muscle activity and active forces during automatic postural responses in cats standing at multiple postural configurations. This characterization depended critically upon the assumption that the endpoint force vector (synergy force vector) produced by the activation of each muscle synergy rotated with the limb axis as the hindlimb posture varied in the sagittal plane. Here, we used a detailed, 3D static model of the hindlimb to confirm that this assumption is biomechanically plausible: as we varied the model posture, simulated synergy force vectors rotated monotonically with the limb axis in the parasagittal plane (r2=0.94+/-0.08). We then tested whether a neural strategy of using these five functional muscle synergies provides the same force-generating capability as controlling each of the 31 muscles individually. We compared feasible force sets (FFSs) from the model with and without a muscle synergy organization. FFS volumes were significantly reduced with the muscle synergy organization (F=1556.01, p<0.01), and as posture varied, the synergy-limited FFSs changed in shape, consistent with changes in experimentally measured active forces. In contrast, nominal FFS shapes were invariant with posture, reinforcing prior findings that postural forces cannot be predicted by hindlimb biomechanics alone. We propose that an internal model for postural force generation may coordinate functional muscle synergies that are invariant in intrinsic limb coordinates, and this reduced-dimension control scheme reduces the set of forces available for postural control.

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

    PubMed

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

    2014-09-01

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

  13. Blood pressure associates with standing balance in elderly outpatients.

    PubMed

    Pasma, Jantsje H; Bijlsma, Astrid Y; Klip, Janneke M; Stijntjes, Marjon; Blauw, Gerard Jan; Muller, Majon; Meskers, Carel G M; Maier, Andrea B

    2014-01-01

    Assessment of the association of blood pressure measurements in supine and standing position after a postural change, as a proxy for blood pressure regulation, with standing balance in a clinically relevant cohort of elderly, is of special interest as blood pressure may be important to identify patients at risk of having impaired standing balance in routine geriatric assessment. In a cross-sectional cohort study, 197 community-dwelling elderly referred to a geriatric outpatient clinic of a middle-sized teaching hospital were included. Blood pressure was measured intermittently (n = 197) and continuously (subsample, n = 58) before and after a controlled postural change from supine to standing position. The ability to maintain standing balance was assessed during ten seconds of side-by-side, semi-tandem and tandem stance, with both eyes open and eyes closed. Self-reported impaired standing balance and history of falls were recorded by questionnaires. Logistic regression analyses were used to examine the association between blood pressure and 1) the ability to maintain standing balance; 2) self-reported impaired standing balance; and 3) history of falls, adjusted for age and sex. Blood pressure decrease after postural change, measured continuously, was associated with reduced ability to maintain standing balance in semi-tandem stance with eyes closed and with increased self-reported impaired standing balance and falls. Presence of orthostatic hypotension was associated with reduced ability to maintain standing balance in semi-tandem stance with eyes closed for both intermittent and continuous measurements and with increased self-reported impaired standing balance for continuous measurements. Continuous blood pressure measurements are of additional value to identify patients at risk of having impaired standing balance and may therefore be useful in routine geriatric care.

  14. Blood Pressure Associates with Standing Balance in Elderly Outpatients

    PubMed Central

    Pasma, Jantsje H.; Bijlsma, Astrid Y.; Klip, Janneke M.; Stijntjes, Marjon; Blauw, Gerard Jan; Muller, Majon; Meskers, Carel G. M.; Maier, Andrea B.

    2014-01-01

    Objectives Assessment of the association of blood pressure measurements in supine and standing position after a postural change, as a proxy for blood pressure regulation, with standing balance in a clinically relevant cohort of elderly, is of special interest as blood pressure may be important to identify patients at risk of having impaired standing balance in routine geriatric assessment. Materials and Methods In a cross-sectional cohort study, 197 community-dwelling elderly referred to a geriatric outpatient clinic of a middle-sized teaching hospital were included. Blood pressure was measured intermittently (n = 197) and continuously (subsample, n = 58) before and after a controlled postural change from supine to standing position. The ability to maintain standing balance was assessed during ten seconds of side-by-side, semi-tandem and tandem stance, with both eyes open and eyes closed. Self-reported impaired standing balance and history of falls were recorded by questionnaires. Logistic regression analyses were used to examine the association between blood pressure and 1) the ability to maintain standing balance; 2) self-reported impaired standing balance; and 3) history of falls, adjusted for age and sex. Results Blood pressure decrease after postural change, measured continuously, was associated with reduced ability to maintain standing balance in semi-tandem stance with eyes closed and with increased self-reported impaired standing balance and falls. Presence of orthostatic hypotension was associated with reduced ability to maintain standing balance in semi-tandem stance with eyes closed for both intermittent and continuous measurements and with increased self-reported impaired standing balance for continuous measurements. Conclusion Continuous blood pressure measurements are of additional value to identify patients at risk of having impaired standing balance and may therefore be useful in routine geriatric care. PMID:25222275

  15. Height-Adjustable Desks: Energy Expenditure, Liking, and Preference of Sitting and Standing.

    PubMed

    Roemmich, James N

    2016-10-01

    Breaking periods of sitting with standing may prevent chronic diseases and increase energy expenditure (EE). Sit-to-stand height adjustable desks may promote workplace standing, but workers have to be willing to stand for portions of the workday. For studies 1 and 2, EE was measured during word processing while sitting in a chair and while standing. Subjects scored their liking of each posture and time they would be willing to work in each posture during an 8-hour workday. Study 2 included an intervention of replacing subjects' sitting desks with a height adjustable desk. Liking of and willingness to work in each posture were measured before and after the 12-month intervention. EE was 7.5 kcal/h greater when standing than when sitting. Subjects liked sitting more than standing in study 1. In study 2, liking of postures did not differ or change across 12 months use of height adjustable desks. Perceived willingness to stand decreased from 4.5 h/d at baseline to 3.4 h/d after 12 months. Standing rather than sitting increased EE by 7.5 kcal/h. Use of a height adjustable desk for 12 months did not alter the hedonic value of standing or sitting, which is promising for long-term increases in standing.

  16. Effects of lumbar extensor fatigue and surface inclination on postural control during quiet stance.

    PubMed

    Lin, Dingding; Nussbaum, Maury A

    2012-11-01

    A number of work environments require workers to perform tasks on inclined surfaces. Such tasks, along with muscle fatigue, can impair postural control and increase falling risks. The objective of this study was to determine the effects of surface inclination angle, standing direction, and lumbar extensor fatigue on postural control during quiet standing. A group of 16 young, healthy participants were tested while standing on inclined surfaces before and after lumbar extensor fatigue (induced by repetitive isotonic exercise). Three inclination angles (0°, 18° and 26°) and three standing directions (uphill, downhill, and lateral facing) were examined. Postural control was assessed using several measures derived from center-of-pressure time series and subjectively perceived stability. Significant main and interactive effects of inclination angle and standing direction were found for all dependent measures. The adverse effects of standing on inclined surfaces were found to differ between the three standing directions. In general, dose-response relationships with inclination angle were evident, particularly in the lateral-facing direction. Fatigue-related effects differed between conditions, suggesting that the adverse effect of lumbar extensor fatigue on postural control depend on inclination angle and standing direction. These findings may facilitate the development of fall prevention interventions for work involving inclined surfaces.

  17. Specificity of Postural Sway to the Demands of a Precision Task at Sea

    ERIC Educational Resources Information Center

    Chen, Fu-Chen; Stoffregen, Thomas A.

    2012-01-01

    Mariners actively adjust their body orientation in response to ship motion. On a ship at sea, we evaluated relations between standing postural activity and the performance of a precision aiming task. Standing participants (experienced mariners) maintained the beam from a handheld laser on a target. Targets were large or small, thereby varying the…

  18. Specificity of Postural Sway to the Demands of a Precision Task at Sea

    ERIC Educational Resources Information Center

    Chen, Fu-Chen; Stoffregen, Thomas A.

    2012-01-01

    Mariners actively adjust their body orientation in response to ship motion. On a ship at sea, we evaluated relations between standing postural activity and the performance of a precision aiming task. Standing participants (experienced mariners) maintained the beam from a handheld laser on a target. Targets were large or small, thereby varying the…

  19. Challenging Postural Tasks Increase Asymmetry in Patients with Parkinson’s Disease

    PubMed Central

    Beretta, Victor Spiandor; Gobbi, Lilian Teresa Bucken; Lirani-Silva, Ellen; Simieli, Lucas; Orcioli-Silva, Diego; Barbieri, Fabio Augusto

    2015-01-01

    The unilateral predominance of Parkinson’s disease (PD) symptoms suggests that balance control could be asymmetrical during static tasks. Although studies have shown that balance control asymmetries exist in patients with PD, these analyses were performed using only simple bipedal standing tasks. Challenging postural tasks, such as unipedal or tandem standing, could exacerbate balance control asymmetries. To address this, we studied the impact of challenging standing tasks on postural control asymmetry in patients with PD. Twenty patients with PD and twenty neurologically healthy individuals (control group) participated in this study. Participants performed three 30s trials for each postural task: bipedal, tandem adapted and unipedal standing. The center of pressure parameter was calculated for both limbs in each of these conditions, and the asymmetry between limbs was assessed using the symmetric index. A significant effect of condition was observed, with unipedal standing and tandem standing showing greater asymmetry than bipedal standing for the mediolateral root mean square (RMS) and area of sway parameters, respectively. In addition, a group*condition interaction indicated that, only for patients with PD, the unipedal condition showed greater asymmetry in the mediolateral RMS and area of sway than the bipedal condition and the tandem condition showed greater asymmetry in the area of sway than the bipedal condition. Patients with PD exhibited greater asymmetry while performing tasks requiring postural control when compared to neurologically healthy individuals, especially for challenging tasks such as tandem and unipedal standing. PMID:26367032

  20. Postural correlates with painful situations.

    PubMed

    Lelard, Thierry; Montalan, Benoît; Morel, Maria F; Krystkowiak, Pierre; Ahmaidi, Said; Godefroy, Olivier; Mouras, Harold

    2013-01-01

    Emotional context may play a crucial role in movement production. According to simulation theories, emotional states affect motor systems. The aim of this study was to compare postural responses assessed by posturography and electromyography when subjects were instructed to imagine themselves in a painful or a non-painful situation. Twenty-nine subjects (22.3 ± 3.7 years) participated in this study. While standing quietly on a posturographic platform, they were instructed to imagine themselves in a painful or non-painful situation. Displacement of the center of pressure (COP), leg muscle electromyographic activity, heart rate, and electrodermal activity were assessed in response to painful and non-painful situations. The anteroposterior path was shorter (p < 0.05) when subjects imagined themselves in a painful situation (M = 148.0 ± 33.4 mm) compared to a non-painful situation (158.2 ± 38.7 mm). Higher tibialis anterior (TA) activity (RMS-TA = 3.38 ± 1.95% vs. 3.24 ± 1.85%; p < 0.001) and higher variability of soleus (SO) activity (variation coefficient of RMS-SO = 13.5 ± 16.2% vs. M = 9.0 ± 7.2%; p < 0.05) were also observed in painful compared to non-painful situations. No significant changes were observed for other physiological data. This study demonstrates that simulation of painful situations induces changes in postural control and leg muscle activation compared to non-painful situations, as increased stiffness was demonstrated in response to aversive pictures in accordance with previous results.

  1. Autoimmune Basis for Postural Tachycardia Syndrome

    ClinicalTrials.gov

    2016-10-14

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

  2. Posture Development in Infants at Heightened vs. Low Risk for Autism Spectrum Disorders

    PubMed Central

    Nickel, Lindsay R.; Thatcher, Alyssa R.; Keller, Flavio; Wozniak, Robert H.; Iverson, Jana M.

    2013-01-01

    Evidence suggests that children and adults diagnosed with autism spectrum disorders (ASD) exhibit difficulties with postural control. Retrospective video studies of infants later diagnosed with ASD indicate that infants who eventually receive an ASD diagnosis exhibit delays in postural development. This study investigates early posture development prospectively and longitudinally in 22 infants at heightened biological risk for ASD (HR) and 18 infants with no such risk (Low Risk; LR). Four HR infants received an autism diagnosis (AD infants) at 36 months. Infants were videotaped at home at 6, 9, 12, and 14 months during everyday activities and play. All infant postures were coded and classified as to whether or not they were infant-initiated. Relative to LR infants, HR infants were slower to develop skill in sitting and standing postures. AD infants exhibited substantial delays in the emergence of more advanced postures and initiated fewer posture changes. Because posture advances create opportunities for infants to interact with objects and people in new and progressively more sophisticated ways, postural delays may have cascading effects on opportunities for infant exploration and learning. These effects may be greater for infants with ASD, for whom posture delays are more significant. PMID:24027437

  3. Lumbar spine postures in marines during simulated operational positions.

    PubMed

    Berry, David B; Rodríguez-Soto, Ana E; Su, Jeannie; Gombatto, Sara P; Shahidi, Bahar; Palombo, Laura; Chung, Christine; Jensen, Andrew; Kelly, Karen R; Ward, Samuel R

    2017-01-04

    Low back pain has a 70% higher prevalence in members of the armed forces than in the general population, possibly due to the loads and positions soldiers experience during training and combat. Although the influence of heavy load carriage on standing lumbar spine posture in this population is known, postures in other operationally relevant positions are unknown. Therefore, the purpose of this study was to characterize the effect of simulated military operational positions under relevant loading conditions on global and local lumbar spine postures in active duty male US Marines. Secondary objectives were to evaluate if intervertebral disc degeneration and low back pain affect lumbar spine postures. Magnetic resonance images were acquired on an upright scanner in the following operational positions: Natural standing with no external load, standing with body armor (11.3 kg), sitting with body armor, and prone on elbows with body armor. Custom software was used to measure global lumbar spine posture: Lumbosacral flexion, sacral slope, lordosis, local measures of intervertebral angles, and intervertebral distances. Sitting resulted in decreased lumbar lordosis at all levels of the spine except L1-L2. When subjects were prone on elbows, a significant increase in local lordosis was observed only at L5-S1 compared with all other positions. Marines with disc degeneration (77%) or history of low back pain (72%) had decreased lumbar range of motion and less lumbar extension than healthy Marines. These results indicate that a male Marine's pathology undergoes a stereotypic set of postural changes during functional tasks, which may impair performance. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:XX-XX, 2017.

  4. Postural stability in patients with chronic subdural hematoma.

    PubMed

    Sundström, Nina; Djerf, Linda; Olivecrona, Zandra; Koskinen, Lars-Owe D

    2016-08-01

    Gait disturbances and falls are common in patients with chronic subdural hematoma (cSDH). Postural stability is mainly visually assessed and has not been described using an objective and quantitative measurement tool. The objective of this prospective study was to evaluate postural stability in cSDH patients by measuring trunk sway during stance and gait compared to healthy elderly (HE). It was also to evaluate the relationships among postural stability and age, hematoma size, brain midline shift and hematoma location. Using a gyroscopic method, trunk sway was measured in 22 cSDH patients preoperatively, 5 postoperatively and 58 HE during seven standing and walking tasks. Trunk sway amplitude and velocity in the anterior-posterior and medial-lateral directions were assessed. Postural stability was reduced in the cSDH group compared to HE for all standing tasks. During gait, the sway angle was increased while velocity was decreased in the cSDH group. Only 18 % of the patients could perform all tasks without losing their balance. Postoperatively, postural stability was normalized in the medial-lateral direction during standing. There were no correlations among age, hematoma size, brain midline shift or location of the hematoma and trunk sway. The majority of cSDH patients had reduced postural stability that was partly reversed soon after surgery. It was not correlated to hematoma characteristics, indicating that an increased risk to fall is present regardless of hematoma size and midline shift. This must be accounted for when handling these patients and measures taken to prevent further fall accidents during hospital stays.

  5. The relationship between fear of falling and human postural control.

    PubMed

    Davis, Justin R; Campbell, Adam D; Adkin, Allan L; Carpenter, Mark G

    2009-02-01

    This study was designed to improve the understanding of how standing at elevated surface heights and the associated changes in the visual field affect human balance control. Healthy young adults stood at four different surface heights (ground, 0.8, 1.6 and 3.2 m) under three different visual conditions (eyes open, eyes closed and eyes open with peripheral vision occluded). Mean position, Mean Power Frequency (MPF) and Root Mean Square (RMS) of centre of pressure (COP) displacements were calculated from 60s standing trials, and psychosocial and physiological measures of fear and anxiety were also collected. When standing at a height of 3.2 m, 10 of 36 participants reported an increase in anxiety and a robust fear response while the remaining 26 participants experienced only an increase in anxiety and no fear response. A between subjects analysis of the effect of surface height on postural control revealed that fearful and non-fearful participants adopted different postural control strategies with increased heights. Non-fearful participants demonstrated a postural response characterized by increased MPF and decreased RMS of COP displacements with increasing heights. In contrast, fearful participants demonstrated both increasing MPF and RMS of COP displacements with increasing heights. These findings demonstrate, for the first time, a direct relationship between fear of falling and the strategies used for human postural control.

  6. The role of lumbopelvic posture in pelvic floor muscle activation in continent women.

    PubMed

    Capson, Angela Christine; Nashed, Joseph; Mclean, Linda

    2011-02-01

    This study was undertaken to determine the effect of changing standing lumbopelvic posture on pelvic floor muscle (PFM) activation amplitude and timing and the resultant vaginal manometry values recorded during static and dynamic tasks. Sixteen nulliparous, continent women between the ages of 22 and 41 years performed five tasks (quiet standing, maximal effort cough, Valsalva manoeuvre, maximum voluntary contraction (MVC) of the PFMs, and a load-catching task) in three different standing postures (normal lumbopelvic posture, hyperlordosis and hypolordosis). Electromyographic (EMG) data were recorded from the PFMs bilaterally using a Periform™ vaginal probe coupled to Delsys™ Bagnoli-8 EMG amplifiers. In separate trials, vaginal manometry was obtained using a Peritron™ perineometer. Lumbopelvic angle was recorded simultaneously with EMG and vaginal manometry using an Optotrak™ 3D motion analysis system to ensure that subjects maintained the required posture throughout the three trials of each task. All data were filtered using a moving 100 ms RMS window and peak values were determined for each trial and task. Repeated-measures analyses of variance were performed on the peak PFM EMG, intra-vaginal pressure amplitudes, and lumbopelvic angles as well as activation onset data for the cough and load-catching tasks. There was significantly higher resting PFM activity in all postures in standing as compared to supine, and in the standing position, there was higher resting PFM activity in the hypo-lordotic posture as compared to the normal and hyperlordotic postures. During the MVC, cough, Valsalva, and load-catching tasks, subjects generated significantly more PFM EMG activity when in their habitual posture than when in hyper- or hypo-lordotic postures. Conversely, higher peak vaginal manometry values were generated in the hypo-lordotic posture for all tasks in all cases. These results clearly indicate that changes in lumbopelvic posture influence both the

  7. Anticipatory postural adjustments modify the movement-related potentials of upper extremity voluntary movement.

    PubMed

    Yoshida, S; Nakazawa, K; Shimizu, E; Shimoyama, I

    2008-01-01

    To elucidate the effect on movement-related potentials (MRPs) of anticipatory postural adjustments (APAs) accompanied by voluntary focal movement, we examined the MRPs of shoulder flexion movement under standing and sitting postural conditions in 12 normal subjects. MRPs were evaluated based on three components: readiness potential (RP), motor potential (MP), and movement-monitoring potential. APAs were observed in the activities of postural muscles including the biceps femoris and erector spinae muscles only under standing conditions. The amplitudes of the three MRP components were larger under standing conditions than under sitting conditions for all recorded electrode positions, and the RP and MP amplitudes at the vertex position, which lies over the supplementary motor area (SMA), showed a prominent increase under standing conditions with the highest statistical significance. These results suggest that a recruited neural process of the cortical area including the SMA may be necessary to generate voluntary movement accompanied by APA.

  8. Lighten up: Specific postural instructions affect axial rigidity and step initiation in patients with Parkinson’s disease

    PubMed Central

    Cohen, Rajal G.; Gurfinkel, Victor S.; Kwak, Elizabeth; Warden, Amelia C.; Horak, Fay B.

    2015-01-01

    Background Parkinson’s disease (PD) is associated with stooped postural alignment, increased postural sway, and reduced mobility. The Alexander Technique (AT) is a mindfulness-based approach to improving posture and mobility by reducing muscular interference while maintaining upward intentions. Evidence suggests that AT can reduce disability associated with PD, but a mechanism for this effect has not yet been established. Objective We investigated whether AT-based instructions reduce axial rigidity and increase upright postural alignment, and whether these instructions have different effects on postural alignment, axial rigidity, postural sway, and mobility than effort-based instructions regarding posture. Method Twenty subjects with PD practiced two sets of instructions and then attempted to implement both approaches (as well as a relaxed control condition) during quiet standing and step initiation. The ‘Lighten Up’ instructions relied on AT principles of reducing excess tension while encouraging length. The ‘Pull Up’ instructions relied on popular concepts of effortful posture correction. We measured kinematics, resistance to axial rotation, and ground reaction forces. Results Both sets of experimental instructions led to increases in upright postural alignment relative to the control condition. Only the Lighten Up instructions led to reduced postural sway, reduced axial postural tone, greater modifiability of tone, and a smoother center of pressure trajectory during step initiation, possibly indicating greater movement efficiency. Conclusion Mindful movement approaches such as AT may benefit balance and mobility in subjects with PD by acutely facilitating increased upright postural alignment while decreasing rigidity. PMID:25665828

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

    PubMed

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

    2006-01-01

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

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

    PubMed

    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.

  11. Lumbar posture and muscular activity while sitting during office work.

    PubMed

    Mörl, Falk; Bradl, Ingo

    2013-04-01

    Field study, cross-sectional study to measure the posture and sEMG of the lumbar spine during office work for a better understanding of the lumbar spine within such conditions. There is high incidence of low back pain in office workers. Currently there is little information about lumbar posture and the activity of lumbar muscles during extended office work. Thirteen volunteers were examined for around 2h of their normal office work. Typical tasks were documented and synchronised to a portable long term measuring device for sEMG and posture examination. The correlation of lumbar spine posture and sEMG was tested statistically. The majority of time spent in office work was sedentary (82%). Only 5% of the measured time was undertaken in erect body position (standing or walking). The sEMG of the lumbar muscles under investigation was task dependent. A strong relation to lumbar spine posture was found within each task. The more the lumbar spine was flexed, the less there was activation of lumbar muscles (P < .01). Periods of very low or no activation of lumbar muscles accounted for about 30% of relaxed sitting postures. Because of very low activation of lumbar muscles while sitting, the load is transmitted by passive structures like ligaments and intervertebral discs. Due to the viscoelasticity of passive structures and low activation of lumbar muscles, the lumbar spine may incline into de-conditioning. This may be a reason for low back pain. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    PubMed

    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.

  13. The influence of the aquatic environment on the control of postural sway.

    PubMed

    Marinho-Buzelli, Andresa R; Rouhani, Hossein; Masani, Kei; Verrier, Mary C; Popovic, Milos R

    2017-01-01

    Balance training in the aquatic environment is often used in rehabilitation practice to improve static and dynamic balance. Although aquatic therapy is widely used in clinical practice, we still lack evidence on how immersion in water actually impacts postural control. We examined how postural sway measured using centre of pressure and trunk acceleration parameters are influenced by the aquatic environment along with the effects of visual information. Our results suggest that the aquatic environment increases postural instability, measured by the centre of pressure parameters in the time-domain. The mean velocity and area were more significantly affected when individuals stood with eyes closed in the aquatic environment. In addition, a more forward posture was assumed in water with eyes closed in comparison to standing on land. In water, the low frequencies of sway were more dominant compared to standing on dry land. Trunk acceleration differed in water and dry land only for the larger upper trunk acceleration in mediolateral direction during standing in water. This finding shows that the study participants potentially resorted to using their upper trunk to compensate for postural instability in mediolateral direction. Only the lower trunk seemed to change acceleration pattern in anteroposterior and mediolateral directions when the eyes were closed, and it did so depending on the environment conditions. The increased postural instability and the change in postural control strategies that the aquatic environment offers may be a beneficial stimulus for improving balance control.

  14. Sympathovagal balance analysis in idiopathic postural orthostatic tachycardia syndrome.

    PubMed

    Russo, Vincenzo; De Crescenzo, Ilaria; Ammendola, Ernesto; Santangelo, Lucio; Calabrò, Raffaele

    2007-08-01

    The idiopathic postural tachycardia syndrome (POTS) is a complex disorder characterized by chronic orthostatic symptoms and an increase in heart rate within 10 minutes of standing on upright posture, without significant orthostatic hypotension. We describe a case of a 36 year-old patient with POTS, diagnosed by head-up tilt testing. Power spectral analysis of heart rate variability (HRV), performed during the tilt test, revealed the ratio of low and high frequency powers (LF/HF) that increased with the onset of orthostatic intolerance. The increase in LF/HF power ratio may represent sympathetic beta-receptors hyperactivity. Atenolol alleviated his clinical symptoms.

  15. The lumbosacral segment as a vulnerable region in various postures

    NASA Technical Reports Server (NTRS)

    Rosemeyer, B.

    1978-01-01

    The lumbosacral region in man is exposed to special static and dynamic load. In a supine position, the disc size increases because of the absence of axial load. In a standing position, with physiological posture of the spine, strain discomfort occurs which is increased even more in the sitting position due to the curvature of the lumbar region of the spine and the irregular distribution of pressure in the discs as a result of this. This special problem of sitting posture can be confirmed by examinations.

  16. Mechanical Characteristics of Reflex Durign Upright Posture in Paralyzed Subjects

    NASA Astrophysics Data System (ADS)

    Kim, Yongchul; Youm, Youngil; Lee, Bumsuk; Kim, Youngho; Choi, Hyeonki

    The characteristics of flexor reflexes have been investigated in the previous studies with human subjects who were seated or supine position. However, researchers did not describe how the spinal circuits are used in different hip angles for paralyzed subjects, such as the standing position with walker or cane. In upright posture the compatibility between a flexor reflex of leg and body balance is a special problem for lower limb injured subjects. Therefore, the purpose of this study was to investigate the effects of hip angle change on the flexor reflex evoked in standing paralyzed subjects supported by walker. In this study, six spinal cord injured and four stroke subjects were recruited through the inpatient physical therapy clinics of Korea national rehabilitation hospital. A single axis electronic goniometer was mounted on the lateral side of the hip joint of the impaired limb to record movements in the sagittal plane at this joint. The electronic goniometer was connected to a data acquisition system, through amplifiers to a computer. Since subject' posture influenced characteristics of the flexion reflex response, the subjects were supported in an upright posture by the help of parallelogram walder. Two series of tests were performed on each leg. The first series of the tests investigated the influence of hip angle during stationary standing posture on flexion reflex response. The hip angle was adjusted by the foot plate. The second examined the effect of the voluntary action of subject on swing motion during the gait. The electrically induced flexion reflex simultaneously produced the flexion of the hip, knee and dorsiflexion of the ankle enabling the swing phase of walking. Form the experimental results we observed that the reflex response of hip joint was largerwith the hip in the extended position than in the flexed position during standing posture. Under voluntary movement on flexion reflex during gaint, the peak hip angle induced by stimulation was

  17. Postural Orthostatic Tachycardia Syndrome

    PubMed Central

    2014-01-01

    The postural orthostatic tachycardia syndrome is a disease characterized by excessively increased heart rate during orthostatic challenge associated with symptoms of orthostatic intolerance including dizziness, exercise intolerance, headache, fatigue, memory problems, nausea, blurred vision, pallor, and sweating, which improve with recumbence. Postural orthostatic tachycardia syndrome patients may present with a multitude of additional symptoms that are attributable to vascular vasoconstriction. Observed signs and symptoms in a patient with postural orthostatic tachycardia syndrome include tachycardia at rest, exaggerated heart rate increase with upright position and exercise, crushing chest pain, tremor, syncope, loss of vision, confusion, migraines, fatigue, heat intolerance, parasthesia, dysesthesia, allodynia, altered traditional senses, and thermoregulatory abnormalities. There are a number of possible dermatological manifestations of postural orthostatic tachycardia syndrome easily explained by its recently discovered pathophysiology. The author reports the case of a 22-year-old woman with moderate-to-severe postural orthostatic tachycardia syndrome with numerous dermatological manifestations attributable to the disease process. The cutaneous manifestations observed in this patient are diverse and most noticeable during postural orthostatic tachycardia syndrome flares. The most distinct are evanescent, hyperemic, sharply demarcated, irregular patches on the chest and neck area that resolve upon diascopy. This distinct “evanescent hyperemia” disappears spontaneously after seconds to minutes and reappears unexpectedly. Other observed dermatological manifestations of this systemic disease include Raynaud’s phenomenon, koilonychia, onychodystrophy, madarosis, dysesthesia, allodynia, telogen effluvium, increased capillary refill time, and livedo reticularis. The treatment of this disease poses a great challenge. The author reports the unprecedented use of an

  18. [The influence of posture on transmission and absorption of vibration energy in whole body vibration exercise].

    PubMed

    Berschin, G; Sommer, H-M

    2010-03-01

    Muscle exercise using whole body vibration platforms is well known as an alternative physical exercise in therapy as well as in high performance sports. Various studies could show an effectiveness in particular to improve maximal strength and springiness. Using these platforms there is no consideration to posture although the damage potential of vibration stress i. e. on intervertebral discs is well-known. Therefore the effect of posture on the transmission and absorption of vibration loads in bipedal standing was examined in a study with 20 sport students. They were exposed to a whole body vibration load in bipedal standing at a vibration frequency of 25 Hz. The transmission of energy was measured at the head in different postural positions. An average transmission of 9 % was measured in spontaneous bipedal standing. It significantly decreased with gradual changes of posture. After 6 weeks posture conditioning exercise this effect was significantly improved. In conclusion different posture in bipedal standing implies not only different energy absorption but also different effects on muscle performance which can explain the partly inconsistent results after vibration exercise. In addition whole body vibration exercise in a prone or sitting position may increase the risk of overload and should be avoided because of reduced energy absorption capacity.

  19. Comparison of postural stability between injured and uninjured ballet dancers.

    PubMed

    Lin, Cheng-Feng; Lee, I-Jung; Liao, Jung-Hsien; Wu, Hong-Wen; Su, Fong-Chin

    2011-06-01

    Ballet movements require a limited base of support; thus, ballet dancers require a high level of postural control. However, postural stability in ballet dancers is still unclear and needs to be understood. To evaluate ballet dancers' postural stability in performing single-leg standing, the en pointe task, and the first and fifth positions and to determine differences in task performance among healthy nondancers, healthy dancers, and dancers with ankle sprains. Controlled laboratory study. Injured dancers, uninjured dancers, and nondancers were recruited for this study (N = 33 age-matched participants; n= 11 per group). The tasks tested were single-leg standing with eyes open and closed, first position, fifth position, and en pointe. Center of pressure parameters were calculated from the ground-reaction force collected with 1 force plate. Analysis of variance was used to assess the differences of center of pressure parameters among 3 groups in single-leg standing; independent t test was used to examine the differences of center of pressure parameters between injured and uninjured dancers. During single-leg standing, injured dancers had significantly greater maximum displacement in the medial-lateral direction and total trajectory of center of pressure, compared with the uninjured dancers and nondancers. During the first and fifth positions, the injured dancers demonstrated significantly greater standard deviation of center of pressure position in the medial-lateral and anterior-posterior directions, compared with the uninjured dancers. During en pointe, the injured dancers had significantly greater maximum displacement in the medial-lateral direction and the anterior-posterior direction, compared with the uninjured dancers. The injured and uninjured dancers demonstrated differences in postural stability in the medial-lateral direction during single-leg standing and the ballet postures. Although the injured dancers received ballet training, their postural stability

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

    PubMed

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

    2010-12-01

    The degree of multiscale complexity in human behavioral regulation, such as that required for postural control, appears to decrease with advanced aging or disease. To help delineate causes and functional consequences of complexity loss, we examined the effects of visual and somatosensory impairment on the complexity of postural sway during quiet standing and its relationship to postural adaptation to cognitive dual tasking. Participants of the MOBILIZE Boston Study were classified into mutually exclusive groups: controls [intact vision and foot somatosensation, n = 299, 76 ± 5 (SD) yr old], visual impairment only (<20/40 vision, n = 81, 77 ± 4 yr old), somatosensory impairment only (inability to perceive 5.07 monofilament on plantar halluxes, n = 48, 80 ± 5 yr old), and combined impairments (n = 25, 80 ± 4 yr old). Postural sway (i.e., center-of-pressure) dynamics were assessed during quiet standing and cognitive dual tasking, and a complexity index was quantified using multiscale entropy analysis. Postural sway speed and area, which did not correlate with complexity, were also computed. During quiet standing, the complexity index (mean ± SD) was highest in controls (9.5 ± 1.2) and successively lower in the visual (9.1 ± 1.1), somatosensory (8.6 ± 1.6), and combined (7.8 ± 1.3) impairment groups (P = 0.001). Dual tasking resulted in increased sway speed and area but reduced complexity (P < 0.01). Lower complexity during quiet standing correlated with greater absolute (R = -0.34, P = 0.002) and percent (R = -0.45, P < 0.001) increases in postural sway speed from quiet standing to dual-tasking conditions. Sensory impairments contributed to decreased postural sway complexity, which reflected reduced adaptive capacity of the postural control system. Relatively low baseline complexity may, therefore, indicate control systems that are more vulnerable to cognitive and other stressors.

  1. The influence of handlebar-hands position on spinal posture in professional cyclists.

    PubMed

    Muyor, José M

    2015-01-01

    Systematic repetition or prolonged posture in specific postures adopted during training could generate modifications on the sagittal spinal curvatures. Spinal alteration in its physiologic curvatures in the sagittal plane has been associated with predisposition to spinal disorders. The objective was to evaluate and compare the changes produced on the sagittal thoracic and lumbar spinal curvatures, and pelvic tilt from standing posture on the floor to upper, middle, lower and aerodynamic handlebars postures adopted on their own road bicycles. A total of twenty-eight male professional cyclists (179.92 ± 5.78 cm; 67.18 ± 5.74 kg) participated in the study. Cyclists had an experience of 17.22 ± 6.16 years in cycling, and spent 6.52 ± 0.51 days per week and 3.78 ± 0.61 hours per day training on their bicycles. Sagittal spinal curvatures (thoracic and lumbar) and pelvic tilt were measured in the standing position on the floor and while sitting on a bicycle with different handlebar-hand positions (high, middle, low and aerodynamic) using a Spinal Mouse system. The thoracic spine showed significantly greater angular values while in a standing posture than on the bicycle in all handlebar-hands postures evaluated. The lumbar curvature changed from lordosis (negative values – anterior convexity) in standing posture to kyphosis (positive values – posterior convexity) in all handlebar-hands positions on the bicycle. The aerodynamic handlebar positions showed the greatest lumbar flexion (lumbar kyphosis) and anterior pelvic tilt. Professional cyclists passively maintain their thoracic spine straighter on the bicycle due to handlebar-hands support than in standing posture. However, the lumbar spine is flexed on the bicycle in all handlebar-hands evaluated. The pelvis is modified to greater anterior pelvic tilt when the handlebar-hands position is farther and lower regarding the saddle of the bicycle.

  2. Effect of Posture during Trumpet and Marching Euphonium Performance on the Trunk and Lower Limb Musculoskeletal System

    PubMed Central

    Mitani, Yasuhiro; Kitagawa, Tomomi; Matsugi, Akiyoshi; Mukai, Kouichi

    2013-01-01

    [Purpose] The purpose of the present study was to investigate the effect of trumpet and marching euphonium performance posture on the trunk and lower limb musculoskeletal system. [Subjects] The subjects were 10 female university students. [Methods] Subjects maintained a resting position, a trumpet performance posture, and a marching euphonium performance posture. The angles and muscle activities of the trunk and lower limbs were then measured. [Results] The anterior tilt angle of the trunk decreased significantly in the trumpet and marching euphonium performance postures compared with the resting standing position, as well as in the marching euphonium performance posture compared with the trumpet performance posture. The muscle activity of the cervical paraspinal muscles, upper fibers of the trapezius, and lumbar paraspinal muscles increased significantly in the marching euphonium performance posture compared with the resting standing position, as well as in the marching euphonium performance posture compared with the trumpet performance posture. [Conclusion] The results suggest that the performance position for trumpet and the marching euphonium performance increases the load on the cervical and thoracic musculoskeletal system, which increases with greater instrument weight. However, the same instrument performance postures had no affect on the musculoskeletal system of the lower limbs. PMID:24259926

  3. Spinal curvature and characteristics of postural change in pregnant women.

    PubMed

    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.

  4. Postural orthostatic tachycardia syndrome.

    PubMed

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

    2007-07-01

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

  5. Posture and Movement

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TP3 includes short reports on: (1) Modification of Goal-Directed Arm Movements During Inflight Adaptation to Microgravity; (2) Quantitative Analysis of Motion control in Long Term Microgravity; (3) Does the Centre of Gravity Remain the Stabilised Reference during Complex Human Postural Equilibrium Tasks in Weightlessness?; and (4) Arm End-Point Trajectories Under Normal and Microgravity Environments.

  6. Effort to reduce postural sway affects both cognitive and motor performances in individuals with Parkinson's disease.

    PubMed

    Sciadas, Ria; Dalton, Christopher; Nantel, Julie

    2016-06-01

    To assess the effects of voluntarily reducing postural sway on postural control and to determine the attention level needed to do s