Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “POSTURE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

[Sports in prevention of postural defects].

Posture results from numerous alternating factors and reflects the attitude of an individual towards a definite situation. If the different conditions, namely the capacity and the willingness of posture, do not correspond to the requirements of the situation the "normal" erect posture will change. The development from abnormal posture into irreversible abnormalities and damages in posture is easy. In order to eliminate these risks one can try to reduce the potential of the situation on the one hand and to improve the capacity of the individual through adequate physical exercise on the other. The practice of daily physical activity at school or during leisure time is the best way to compensate for lack of exercise, to modify prolonged unfavourable situations, and to develop the physical capacity in such a way that dangerous loads can be supported without damage. The versatility of training, in combination with adequate gymnastical exercises and sports help to educate the sense of posture and movement with the effect that erect posture can be adopted and maintained. But only children who feel that erect posture is reflecting their personal image will finally keep the erect posture. Special attention is given to elite training in childhood and adolescence, when the vertebral column is particularly exposed to danger by the intensity of the training and must be protected against deformations by carefully chosen preventive measures.

Humans↗
PubMed2001

Perturbed step initiation in cerebellar subjects: 2. Modification of anticipatory postural adjustments.

Although ataxias of stance and gait are frequent manifestations of cerebellar disease, the number of human studies examining stance or gait in cerebellar subjects is limited. In the present study, we examined whether anticipatory postural adjustments were impaired in cerebellar subjects during perturbed and unperturbed step initiation. The first aim was to show possible abnormalities in timing, force and kinematic parameters of anticipatory postural adjustments in unperturbed stepping in cerebellar subjects. Second, we examined the ability of cerebellar subjects to modify anticipatory postural adjustments associated with step initiation in response to a backward translation. Finally, we asked whether cerebellar subjects (and controls) make use of predictive knowledge of perturbation amplitude in perturbed stepping. Only few abnormalities of anticipatory postural adjustments were found in cerebellar subjects compared to controls. Both in the unperturbed and perturbed step conditions, force production as well as step length and step velocity were reduced in cerebellar subjects compared to controls, suggesting compensatory slowing. Cerebellar subjects also appeared to be less able to use predictive information of perturbation amplitude to scale anticipatory postural adjustments than control subjects. Nevertheless, in unperturbed steps, temporal parameters of anticipatory postural adjustments were preserved in cerebellar subjects. When subjects voluntarily initiated a step in response to the surface translation, both control and cerebellar subjects adapted by executing the anticipatory postural adjustments for step more rapidly. Furthermore, both control and cerebellar subjects were able to use online information regarding perturbation amplitude to scale parameters of step initiation in perturbed stepping. Overall, our findings suggest that the cerebellum is neither critical for the basic motor program underlying unperturbed step initiation nor for many adaptive changes occurring during perturbed step initiation. Like its role in predictive scaling of automatic postural responses to external perturbations, the cerebellum appears to be important for predictive adaptation of anticipatory postural adjustments during step initiation.

Adolescent↗
PubMed1989

Relationships of changes in craniofacial morphology, head posture, and nasopharyngeal airway size following mandibular osteotomy.

The aim of the present study was to illustrate a possible relationship between changes in craniofacial morphology after mandibular osteotomy and changes in head posture and nasopharyngeal airway size. The material comprised standardized profile cephalograms of 52 patients with mandibular prognathism, all of whom underwent orthodontic adjustment before mandibular osteotomy. Mean age of the patients was 24.3 years; 12 men and 40 women participated in the study. The first profile radiograph of each patient was taken 1 day before surgical treatment in the natural head (mirror) position. All patients underwent mandibular surgery with a bilateral vertical ramus osteotomy. The cephalometric investigation was repeated approximately 1 year after the surgical procedure (means = 1.12 years). Craniofacial morphology was evaluated by 12 parameters describing sagittal and vertical jaw relationship. Head posture was evaluated by the craniocervical angulation and airway as nasopharyngeal airway size. Pearson's correlation analysis was used to evaluate the relationship between morphology, posture, and airway size before surgery and changes in these parameters after surgery. Before surgical treatment statistically significant correlations were found between posture and many morphologic variables, mostly mandibular. Small correlations were observed between posture and airway size, and airway size and morphology. After the surgical procedure, changes in posture were still related to changes in mandibular morphology, while other correlations between posture and morphology had been eliminated. Changes in nasopharyngeal airway size were not correlated to any changes in morphology, apart from maxillary prognathism, nor to changes in posture. The results indicated that mandibular morphology and function play a significant role in determining head posture.

Adolescent↗
PubMed2006

The effects of prior exposure, warning, and initial standing posture on muscular and kinematic responses to sudden loading of a hand-held box.

BACKGROUND: Twelve percent of work-related low back injuries have been attributed to sudden loading events. When a sudden load is applied to an object that is held in front of the body, postural responses are rapid, yet it is not clear whether these responses differ with respect to initial posture at the time of loading, or by providing prior exposure to, or warning of a sudden loading event. METHODS: Thirty male subjects in either an upright or stooped standing posture held a pre-weighted box that was suddenly pulled downwards. Surface electromyography techniques were used to detect onset latencies of seven muscles of the right lower limb and trunk, and two-dimensional motion data in the sagittal plane were simultaneously collected. The first trial involved sudden unexpected loading in the upright standing posture, without any prior experience or warning of the loading event. This was followed by a series of randomised loading trials in the upright and stooped standing posture, with and without prior warning of the loading event. FINDINGS: Prior exposure and warning was found to influence postural responses in the upright standing posture, decreasing muscle and joint onset latencies, and resultant maximal angular displacement of the trunk and lower limb. Perturbation in the stooped posture was less reliant on abdominal muscle activation and produced an overall different joint movement initiation pattern, with less joint displacement than in the upright standing position. INTERPRETATION: These findings indicate that prior exposure to, and warning of a sudden loading event lead to changes in postural responses and decreased joint excursion. These changes may contribute to increased stability and decreased risk of musculoskeletal injury.

Abdominal Muscles↗
PubMed2004

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

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.

Adaptation, Physiological↗
PubMed2006

Bone density spatial patterns in the distal radius reflect habitual hand postures adopted by quadrupedal primates.

Primates adopt diverse hand postures during terrestrial and above-branch quadrupedal locomotion--knuckle-walking, digitigrady, and palmigrady--that incorporate varying degrees of wrist dorsiflexion (i.e., extension). Although relationships between hand postures, wrist joint range of motion, and the external properties of wrist bones (e.g., surface morphology) have been examined, the relationship between hand postures and the internal properties of wrist bones (e.g., bone density) remains largely unexplored. Because articular joint surfaces transmit mechanical loads between conjoining limb bones, measures of density (e.g., magnitudes and patterns) in the subchondral cortical plate of bone of the distal radius can be used to evaluate load regimes experienced by the wrist joint in different hand postures. We assessed apparent (i.e. optical) density patterns in several extant catarrhine primate taxa partitioned into different hand posture groups: knuckle-walking apes, digitigrade monkeys, and palmigrade monkeys. Computed tomography osteoabsorptiometry (CT-OAM) was used to construct maximum intensity projection (MIP) maps of apparent densities. High apparent density areas were characterized relative to a dorsal-volar reference plane and compared across hand posture groups. All groups had large percentage areas of high apparent density in the dorsal region of the distal radial articular surface. Only knuckle-walking apes, however, had a large percentage area of high apparent density in the volar region of the distal radial articular surface. These patterns are consistent with radiocarpal articulations in specific hand postures as evidenced by available radiographic data and suggest that the different habitual hand postures adopted by monkeys and African apes during quadrupedal locomotion have different stereotypic loading patterns. This has implications for understanding the functional morphology and evolution of knuckle-walking and digitigrade hand postures in primates.

Animals↗
PubMedDate not supplied

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

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

Adult↗
PubMed2005

Shoulder impingement: the effect of sitting posture on shoulder pain and range of motion.

The re-education of spinal posture is an integral part of shoulder impingement management yet supporting evidence is limited. The purpose of this study was to evaluate the effect of slouched versus erect sitting posture on shoulder pain intensity and range of motion (ROM) in subjects with impingement. A same-subject repeated-measures design was utilized. Maximum active shoulder flexion and associated pain intensity were measured in 28 subjects in slouched and erect sitting postures, using video-analysis and visual analogue scales, respectively. An intra-tester reliability study of the video-analysis system was completed and intra-class correlation coefficients calculated. Shoulder flexion differences between slouched and erect sitting posture were analysed using a repeated-measures analysis of variance (ANOVA). The intra-tester reliability of the video-analysis method was found to be 'excellent' (ICC = 0.99). Flexion ROM was significantly greater in the erect sitting posture (F = 100.3, P < 0.0001); the mean ROM difference between postures was 17.67 degrees (+/- 9.17 degrees). There was no significant difference in pain intensity between postures (F = 1.9, P = 0.179). An erect sitting posture appeared to increase active shoulder flexion in subjects with shoulder impingement, although there were no differences in reported pain intensity. Further research is required to investigate the long-term effects of postural re-education.

Adult↗
PubMed2006

Recruitment of the deep cervical flexor muscles during a postural-correction exercise performed in sitting.

Specific strategies to optimally facilitate postural muscles to retrain postural form are advocated in the clinical management of neck pain. The purpose of this study was to compare the activation of selected cervical, thoracic and lumbar muscles during independent and facilitated postural correction in sitting in 10 subjects with chronic neck pain. Deep cervical flexor (DCF) muscle activity was recorded with custom electrodes inserted via the nose and fixed by suction to the posterior mucosa of the oropharynx. Surface electrodes were placed over the thoracic erector spinae and lumbar multifidus muscles. Root-mean-square EMG amplitude was measured for each muscle across two conditions. In the first condition, subjects were instructed to spontaneously "sit up straight" from a slumped posture without any other guidance from the therapist. In the second condition the therapist provided specific manual and verbal facilitation to assist the patient to correct to an upright pelvic position with a neutral spinal lumbo-pelvic position. Activation of the DCF and lumbar multifidus muscles (P<0.05) were significantly greater when the therapist facilitated postural correction compared to independent sitting correction. Specific postural-correction strategies result in better facilitation of key postural muscles compared to non-specific postural advice. The results of this study highlight the need for clinical skill and precision in postural training of patients with neck pain.

Adult↗
PubMed1999

Measurement of postural stability before and after immersion in a virtual environment.

Research into the effects of simulators has led to suggestions that postural instability occurring after immersion in a virtual reality virtual environment (VR/VE) may have direct implications for the safety of post-immersion activities such as driving or operating machinery. However, experimental studies have highlighted a lack of standardisation in the postural stability measurement techniques applied and subsequent inconsistencies in the results obtained. An experiment was conducted to evaluate the use of static, dynamic and posturographic postural stability measures in determining the effect of participation in an interactive virtual environment (VE) for 20 min. The results demonstrate differences in the sensitivity of postural stability measurement techniques and variations in inter- and intra-individual responses to measures. The VE immersion was found to produce postural instability only when measured using a posturographic technique under normal stance static posture, and then only mildly and not long-lasting. No associations were found between reported symptoms of simulator sickness and postural stability with postural stability measures. This paper discusses issues relating to postural stability measurement and the implications for evaluation of virtual environment effects.

Adult↗
PubMed1998

The development of postural response patterns during reaching in healthy infants.

Reaching movements in adults are accompanied by complex postural adjustments which are controlled by spatial, temporal, and quantitative parameters. The basic postural adjustments are selected on the basis of the spatial parameter, whereas fine tuning of the pattern is guided by temporal and quantitative parameters. In specific conditions, such as during fast arm movements, postural adjustments have an anticipatory character. Recently, the development of postural adjustments during reaching was studied longitudinally in infants aged 3-18 months, placed in supine and sitting positions. The data revealed that already at 4 months, the age at which successful reaching emerges, reaching movements are accompanied by complex postural adjustments. The early postural patterns resembled the adult ones in spatial features (dorso-ventral ordering), temporal characteristics (top-down recruitment), and position dependency. With increasing age the postural patterns changed considerably, including a transient period of less extensive postural activity at 6-8 months, the age at which rolling, sitting up and crawling develops. Postural anticipation during reaching was not consistently present at any age.

Adult↗
PubMed2004

Cognitive influences in postural control of patients with unilateral vestibular loss.

The aim of this study was to investigate the interference between postural control and cognitive processing in patients with surgically confirmed unilateral vestibular lesions. These patients were well-compensated for vestibular lesions with no symptoms of dizziness or definable postural deficit. We hypothesized that attentional processes would play a greater role in postural control of these patients compared to healthy age-matched controls suggesting that successful compensation for a vestibular impairment involves ongoing increased attentional resources, and is not an automatic process. To explore this hypothesis, we used a dual-task paradigm that combined postural challenges with concurrently performed cognitive tasks. The postural conditions were seated, standing on a fixed floor, standing on a sway-referenced floor, and standing on a translating floor. Cognitive tasks were simple, inhibitory, and forced choice reaction time (RT) tasks. Patients had slower RTs compared to the controls under all conditions, including the seated condition. This effect was particularly large for the choice and inhibitory tasks. Both groups had increased RTs as the postural task became more challenging. Postural sway increased similarly in the patients and controls when performing the RT tasks for all postural conditions. These results suggest that patients with vestibular lesions that are well-compensated require increased attention compared to healthy controls; however, this increased demand on attention extends beyond postural control. The site of action may be at the sensory integration level resolving multiple sensory signals for spatial orientation.

Adult↗
PubMed2003

Lower body anatomical distribution of solar ultraviolet radiation on the human form in standing and sitting postures.

Humans undertake their daily activities in a number of different postures. This paper aims to compare the anatomical distribution of the solar erythemal UV to human legs for standing and sitting postures. The exposure ratios to the legs (ratio of the UV exposure to a particular anatomical site compared to the ambient) have been measured with UV dosimeters for standing and sitting postures of a manikin. The exposure ratios for the legs ranged from 0 to 0.75 for the different anatomical sites for the sitting posture in summer (December through February) compared to 0.14 to 0.39 for the standing posture. In winter (June through August) the exposure ratios ranged from 0.01 to 0.91 for sitting to 0.17 to 0.81 for standing. For the anterior thigh and shin, the erythemal UV exposures increased by a factor of approximately 3 for sitting compared to standing postures. The exposure ratios to specific anatomical sites have been multiplied by the ambient erythemal UV exposures for each day to calculate the annual exposures. The annual erythemal exposures to the anterior thigh and ankle were predicted to be higher than 800 MED for humans sitting outdoors each day between noon and 13:00 h Australian Eastern Standard Time (EST). For humans standing outdoors during this time, the annual erythemal UV exposure averaged over each leg site was 436 MED, whereas, the averaged annual erythemal UV exposure was 512 MED for the sitting posture. Similarly, the annual erythemal UV exposure averaged over each of the sites was 173 MED for humans standing outdoors between 09:00 h EST and noon each Saturday morning and 205 MED for humans sitting outdoors during this time. These results show that there is increased risk of non-melanoma skin cancer and malignant melanoma to the lower body if no UV preventative strategies are employed while in a sitting posture compared to a standing posture.

Environmental Exposure↗
PubMed1978

Variations in cerebral organization as a function of handedness, hand posture in writing, and sex.

During the past century, it has become increasingly apparent that there is a great deal of variation in the direction and degree of cerebral lateralization, a plurality of people having language and related functions strongly specialized to the left hemisphere and visuospatial functions strongly specialized to the right, with substantial minorities manifesting various deviations from this pattern. In particular, in 35%-50% of sinistrals and 1%-10% of dextrals, the right hemisphere is specialized for linguistic skills, and in some unknown fraction of the two handedness groups, verbal and/or spatial abilities are, to varying extents, bilateralized. Levy (1973) suggested that the hand posture adopted during writing might be an index of the lateral relationship between the dominant writing hand and the language hemisphere, a normal posture indicating contralateral language specialization, and an inverted posture indicating ipsilateral language specialization. In the present investigation, two tachistoscopic tests of cerebral lateralization, one measuring spatial functions and one measuring verbal function, were administered to 73 subjects classified by handedness, hand posture during writing, and sex. Among both dextral and sinistral subjects with a normal writing posture, language and spatial functions were specialized to the contralateral and ipsilateral hemispheres, respectively, and lateral differentiation of the brain was strong. The reverse was seen in subjects having an inverted writing posture. In all groups, females were less laterally differentiated than males. In 70 out of 73 subjects, the direction of cerebral laterization was accurately predicted by handedness and hand posture. The 3 subjects (2 females and 1 male) who failed to manifest the predicted relations were all left-handers having an inverted hand posture . In this group, lateral differentiation was so weak that the reliability of the tachistoscopic tests was reduced, and we attribute these three predictive failures to this cause. Thus, almost all of the variation in the lateral organization of the brain was accounted for by handedness, hand posture, and sex.

Cerebral Cortex↗
PubMed2002

Management of hip dislocation with postural management.

BACKGROUND: Hip dislocation in children with cerebral palsy has a well-documented history and morbidity. OBJECTIVE: This paper presents a retrospective study of children with bilateral cerebral palsy who had various postural management and its effect on hip deformity. The most widely accepted theoretical model of hip subluxation/dislocation is that an imbalance in muscle length and strength around the hip leads to acetabular dysplasia and consequent hip subluxation. Maintenance of muscle length and strength and loadbearing is therefore a logical prevention. Research on normal infants' postures has provided biomechanical data to form the theoretical basis of 24 h postural management equipment. METHODS: The notes and X-rays of 59 children with bilateral cerebral palsy from East and West Sussex and Oxfordshire were examined and measured to determine whether a relationship existed between postural management and the level of hip subluxation/dislocation. X-rays were measured using Reimers' hip migration percentage. Postural management support was divided into three groups for analysis. Category 1: use of a 24-h postural management approach using Chailey Adjustable Postural Support (CAPS) systems in lying, sitting and standing; category 2: two items of CAPS (either lying/sitting or sitting/standing supports); category 3: use of the CAPS seat only and/or any other postural supports. Hip status was recorded for analysis as both hips safe (under 33% migrated), or one/both hips subluxed. RESULTS: Children using 'All CAPS' before hip subluxation maintained significantly more hip integrity than other groups (chi2 P < 0.05). CONCLUSIONS: Postural management interventions have an important role in the prevention of hip dysplasia.

Adolescent↗
PubMed2001

Postural dynamics: clinical and empirical implications.

OBJECTIVE: To provide a rationale for the examination of posture from a dynamic (behavioral) perspective and to relate the vertebral subluxation to postural instability and motion sickness via inefficiency. DATA COLLECTION: A manual search of available reference texts and a computer search of literature from Index Medicus, PsycINFO, and ISI Science Citation Index Expanded were collected with an emphasis on postural dynamics, vertebral subluxation, and motion sickness. RESULTS: Evidence linking behavioral and health research has emerged from the study of posture and postural dynamics. Studies examining the relation between postural control and motion sickness have shown that motion sickness is preceded and predicted by postural instability. Motion sickness is characterized by maladaptive response to unusual motion events. The symptoms are nonspecific and variable. Although the Postural Instability theory of motion sickness predicted that instability should precede sickness, it did not make any claims regarding the symptoms associated with it. Chiropractic literature has emphasized the effects of vertebral subluxation on neurologic dysfunction. Vertebral subluxation is a condition that is postulated to interfere with neurologic processes and may influence organ system function and general health. As in the case of motion sickness, symptoms are nonspecific and variable (and in some instances the person may have no symptoms). So what do these disorders have in common? In each instance the disruptions lead to inefficiency in the system. CONCLUSION: Given this potential commonality, we propose that some of the methods used by behavioral researchers to study postural dynamics may also be of great utility to health care practitioners and psychologists alike. Furthermore we propose that this link will provide a framework that will allow scientists to address seemingly intractable problems such as motion sickness or subluxation.

Biomechanical Phenomena↗
PubMed2004

Joint angles of isocomfort for female subjects based on the psychophysical scaling of static standing postures.

This study investigated the joint angles of isocomfort (JAIs) for females based on the psychophysical scalings for static standing postures held for 60 s, which were obtained in a laboratory experiment. The subjects were instructed to rate their comfort levels for varyious joint postures by using the free modulus method of magnitude estimation. The comfort scores for the joint postures and the related verbal comfort categories were subjected to regression analysis in order to obtain the JAIs corresponding to verbal categories. The results showed that the JAIs were significantly different depending upon the joints and joint postures investigated (p < 0.01), and that the JAIs for female subjects were significantly different than those for males (p < 0.01) which had been obtained in an earlier study (Kee and Karwowski, 2001). Compared to the corresponding range of joint motion values, the JAIs for hip postures were the smallest of all joint postures dealt with in this study, while those for the neck were the largest of all postures, which means that hip postures are more stressful than any other joint posture. Based on this study, it is recommended that the gender-based JAI values should be used for design applications.

Adult↗
PubMed1993

Static force exertion in postures with different degrees of freedom.

In assessing human force exertion, the use of standardized postures can lead to the inaccurate prediction of the forces and postures which occur in everyday life. Therefore force data obtained using postures freely chosen by subjects themselves may be considered more relevant. A standardized posture, however, is considered to yield more reliable data. The question arose whether it would be possible to combine the two in some way, calling the result a 'functional posture'. Research was necessary to determine a way of operationalizing these functional postures, and to test their reproducibility. First, a method is proposed to describe functional postures through explorative research. This includes the fixation of members that transfer force to the outside world, while the rest of the body is allowed to move freely. The results of further research show that the exerted force is reproducible in free, functional, and standardized postures. The difference in average force, though, is considerable and significant. The conclusion is that force exertion in free posture is most suitable for design research.

Adult↗