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.

SourceResearch connectionFrom yearThrough year

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

At least 1,171 records · Page 65Linked to original sources

PubMed1999

Wrist and forearm postures and motions during typing.

Awkward upper extremity postures and repetitive wrist motions have been identified by some studies as risk factors for upper extremity musculoskeletal disorders during keyboard work. However, accurate body postures and joint motions of typists typing on standardized workstations are not known. A laboratory study was conducted to continuously measure wrist and forearm postures and motions of 25 subjects while they typed for 10-15 min at a standard computer workstation adjusted to the subjects' anthropometry. Electrogoniometers continuously recorded wrist and forearm angles. Joint angular velocities and accelerations were calculated from the postural data. The results indicate that wrist and forearm postures during typing were sustained at non-neutral angles; mean wrist extension angle was 23.4 +/- 10.9 degrees on the left and 19.9 +/- 8.6 degrees on the right. Mean ulnar deviation was 14.7 +/- 10.1 degrees on the left and 18.6 +/- 5.8 degrees on the right. More than 73% of subjects typed with the left or right wrist in greater than 15 degrees extension and more than 20% typed with the left or right wrist in greater than 20 degrees ulnar deviation. Joint angles and motions while typing on an adjusted computer workstation were not predictable based on anthropometry or typing speed and varied widely between subjects. Wrist motions are rapid and are similar in magnitude to wrist motions of industrial workers performing jobs having a high risk for developing cumulative trauma disorders. The magnitude of the dynamic components suggests that wrist joint motions may need to be evaluated as a risk factor for musculoskeletal disorders during typing.

Adult↗

PubMed1997

Virtual Time-to-Collision and Human Postural Control.

This article is a report on 3 experiments designed so that the role of virtual time-to-collision (VTC), which specifies the spatiotemporal proximity of the center of pressure to the postural stability boundary in the regulation of posture in upright stances, could be examined. Virtual time-to-collision was estimated for normal upright stance with different bases of support, and for postural oscillations in which the speed of movement and instructional constraints on the coordination mode used were manipulated. The results showed that virtual time-to-collision was predictably reduced as (a) the base of support was reduced, (b) the speed of the postural oscillation was increased, and (c) the number of biomechanical degrees of freedom regulated in the coordination mode increased. Over a range of task conditions, the coefficients of variation of the VTC time-series were significantly lower than the coefficients of variation for the velocity and acceleration time-series of the center of pressure. The absolute values of VTC increased with the increment of the ground reaction forces a performer generated to avoid falling while approaching the stability boundary. These findings are consistent with the proposition that VTC may serve as an organizing informational control parameter for posture.

center of pressure↗

PubMed1988

Spasmodic torticollis-like posture and caudate nucleus monoamine in cats: in vivo dialysis study.

In order to study the monoamine mechanism in the caudate nucleus of experimental spasmodic torticollis, the left side of the ventromedial tegmentum (VMT) was electrically destroyed in cats, and in vivo brain dialysis in the caudate nucleus was performed for determining the changes in monoamines and their metabolites. Six out of 12 animals showed the torticollis-like posture in which the head became deviated towards the side of the lesion by rotating around the longitudinal axis. In 4 of these 6 cats, this posture continued for 3 d until brain dialysis was performed. The extracellular 5-HIAA level decreased compared to HVA level in the caudate nucleus of the lesion side. In the other 2 cats, the posture disappeared on the day after the lesion was induced and the change of 5-HIAA level was less prominent or within the range of the control group. The brain dialysis method was very useful for measuring the monoamine metabolite levels of the caudate nucleus while the experimental model was still alive and presenting the torticollis-like posture. These results suggest, although inconclusively, that decreased activity in the ipsilateral caudate nucleus serotonin neuron might play an important role in the manifestation of the torticollis-like posture in this animal model.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1991

Alteration of vertical dimension and its effect on head and neck posture.

Previous research has shown a relationship between head posture and rest position of the mandible. Should this relationship really be an interrelationship? Does a change in mandibular posture alone also alter head and neck posture? The purpose of this article is to demonstrate how a change in mandibular posture, specifically an increase in vertical dimension, contributes to craniovertical extension leading to suboccipital compression and upsetting the postural balance between the head and neck. A model of physiologic equilibrium is presented for the craniomandibular articulation.

Adaptation, Physiological↗

PubMed1996

Body posture photographs as a diagnostic aid for musculoskeletal disorders related to temporomandibular disorders (TMD).

The purpose of this study was to test the hypothesis that body posture could be an etiologic factor in patients with temporomandibular disorders. "Faculty" body posture has been considered to be an initiating and perpetuating etiologic factor in some temporomandibular disorders (TMD). Although in patients with temporomandibular disorders a significant craniocervical dysfunction has been established, a causal relationship between posture and TMD has not yet been proved. Two samples of 40 subjects each were selected, age and gender matched. The experimental group consisted of 40 patients, who were not previously treated for temporomandibular dysfunction. TMD of these patients was diagnosed on the basis of a questionnaire and a thorough intra- and extraoral examination. The clinical symptoms of TMD were confirmed with transcranial x-rays and the condylar tracings of the performed axiography. A clinical examination was done to confirm the good health of the control group. In addition, symptoms of craniocervical dysfunction within the experimental group were evaluated to make a proper referral to a physical therapist. Four photographs of the orthostatic posture were taken. In accordance with anthropometric guidelines, the following anatomical landmarks were palpated and applied on the skin with a dark lipstick on forehand: both acromiones of the scapula and the anterior (ASIS) and posterior superior iliac spine (PSIS). Statistical testing was performed to confirm the data fit a normal distribution. The differences between the experimental group and the control group were tested with Student's two sample T-test. Within the experimental group, a significant correlation existed between the shoulder line and the pelvis line, on the frontal as well as on the dorsal photograph. The results suggest a somatic basis for the observed postural imbalances in patients with temporomandibular disorders. The results, however, must be interpreted with reservation.

Adolescent↗

PubMed2005

Adaptation of a seated postural control measure for adult wheelchair users.

PURPOSE: Clinical measures of seated postural control in adults are not standardized and most are derived from in-house tools. The purpose of this study is to adapt a pediatric instrument to evaluate seated postural control in adult wheelchair users. METHOD: The new instrument is called the Seated Postural Control Measure for Adults (SPCMA) 1.0. Five preliminary versions were pretested with some 20 adults by two raters and a group of experts. RESULTS: This instrument comprises three sections: Section 1, level of sitting scale for adults (1 item, 7-point ordinal scale); Section 2, static postural alignment (22 items, 7-point ordinal scale); and Section 3, postural alignment after a dynamic activity, propulsion of the wheelchair on flat terrain and an incline (22 items, 7-point ordinal scale). CONCLUSIONS: The SPCMA for Adults 1.0 improves the quality and uniformity of evaluations done by different raters, which facilitates more rigorous follow-up of clients over time, communication between professionals, and objective verification of the attainment of intervention objectives.

Activities of Daily Living↗

PubMed2005

Reliability of the seated postural control measure for adult wheelchair users.

PURPOSE: To evaluate the test-retest and interrater reliability of the Seated Postural Control Measure for Adults 1.0 (SPCMA 1.0). METHOD: The participants were evaluated first by two raters and then, 3 weeks later, by one rater. Section 1 (one item, seven-point scale) evaluates the adult's overall ability to control its posture in a sitting position. Sections 2 and 3 (22 items each, scored on a seven-point scale), evaluate the adult's postural alignment in a static position and the changes in postural alignment induced by a dynamic activity. RESULTS: For the test-retest reliability, the intraclass correlation coefficient (ICC) of section 1 was excellent (0.95) and moderate to good for sections 2 and 3 (0.60 - 0.62) and their subsections (0.47 - 0.78). For interrater reliability, the three sections had good to excellent ICCs (0.68 - 0.93) and their subsections had moderate to good ICCs (0.41 - 0.69). A large range was observed in Kappa coefficients (test-retest and interrater reliability) for the item analysis of the sections 2 and 3, due to a lack of variability in some items. CONCLUSIONS: The results confirm that the SPCMA is reliable as a whole. Suitable information has been obtained for the development of the SPCMA 2.0 and, although further psychometric testing is needed, the latter should improve clinical evaluation of seated postural control in adult wheelchair users.

Activities of Daily Living↗

PubMed2002

Postural sway measurements: a potential safety monitoring technique for workers wearing personal protective equipment.

This study investigated the use of postural sway measurements as a potential safety monitoring technique. Sixteen healthy male volunteers (age: 41.8+/-9.3 years) participated in this study. The level of neurophysiological strain and the ability to maintain upright balance for workers wearing personal protective equipment (PPE) were investigated. Three levels of PPE, the United States Environmental Protection Agency (USEPA)-defined levels A, B, and C, were worn in random order while performing two randomly ordered tasks, resting and a workload. After the workload task, the perceived exertion and discomfort were recorded. Postural sway, measured using a microprocessor-based force platform system, was assessed after each task. The variables of sway area and sway length were calculated from stabilograms. These measurements were taken for three sway tests: 1) Eyes open (EO), 2) Eyes closed on a four-inch foam (FC), and 3) a dynamic test with the subject reaching for a weight placed in front, lifting it to his or her chest, and lowering back to the shelf four times (RE). The heart rate was significantly higher for the workload task (p < 0.05), and the levels A and B PPE demonstrated significantly higher perceived exertion results than level C PPE (p < 0.05). The heart rate and perceived exertion were not significantly correlated with the sway measurements. Level A produced significant self-reported discomfort results for the upper back, lower back, and thighs. The sway variables showed significant differences with the PPE levels and the task. The workload task produced significantly higher sway length than the resting task (p < 0.05) for all test conditions. The PPE level B produced significantly higher sway length than PPE level A (p < 0.05) in the FC test condition. These results indicate that postural stability is altered with PPE use and with fatigued postural muscles. In summary, postural sway measurements may be used as a potential safety monitoring technique.

Adult↗

PubMed2005

Participatory ergonomics and an evaluation of a low-cost improvement effect on cleaners' working posture.

Cleaning is a highly physically demanding job with a high frequency of awkward postures and working environments as contributing risk factors. Participatory ergonomics is a method in which end-users take an active role in identifying risk factors and solutions. The aim of this study was to apply the participatory ergonomics method to identify cleaning problems and to evaluate the effect of a low-cost improvement on cleaners' working postures in an office environment. The results show that the cleaning problem was identified, and the low-cost ergonomics solution suggested by the cleaners was implemented. Thus an improved working environment reduced the number of awkward cleaning postures and the Ovako Working Posture Analysis System (OWAS) action category for floor mopping decreased. It can be concluded that working in an improved environment can lead to better working postures which, in turn, leads to the cleaners' better health and better cleaning results.

Ergonomics↗

PubMed2005

An ergonomic study on posture-related discomfort among preadolescent agricultural workers of West Bengal, India.

In India, particularly in West Bengal, preadolescents are primarily associated with agricultural work in rural areas. Owing to poor socio-economic conditions, they are compelled to carry out a considerable number of manual, rigorous tasks in agricultural fields. The main aim of this study was to investigate postures adopted by preadolescent agricultural workers during individual agricultural activities and to analyze the causes of discomfort related to those postures. Fifty male and 50 female preadolescent agricultural workers were randomly selected and a detailed posture analysis was performed with the Ovako Working Posture Analysis System (OWAS). It was observed that those workers worked continuously in awkward postures during certain agricultural activities. Consequently they suffered from discomfort in different parts of their body. Even though they were very young, they were likely to suffer from serious musculoskeletal disorders in the future.

Agriculture↗

PubMed2001

Postural stability after inguinal herniorrhaphy under local infiltration anaesthesia.

OBJECTIVE: To investigate postural stability in patients after inguinal herniorrhaphy under local infiltration anaesthesia, to see if the anaesthetics and analgesics used influenced it and therefore hindered early discharge. DESIGN: Open study. SETTING: Teaching hospital, Denmark. SUBJECTS: 55 patients listed for elective inguinal herniorrhaphy. INTERVENTIONS: Preoperative and intraoperative infiltration anaesthesia by bupivacaine 2.5 mg/ml (median dose 41 ml, range 30-84 ml), and sedation with midazolam intraoperatively (median dose 3 mg, range 0-10 mg). Lichtenstein tension-free technique with polypropylene mesh repair (Prolene). Measurement of postural stability before operation and 30 and 60 minutes afterwards using the "Basic Balance Master" system, and balance assessed by visual analogue scale and verbal rating scale. MAIN OUTCOME MEASURES: Postural stability and subjectively assessed balance. RESULTS: Dynamic postural stability was impaired 30 min (p < 0.05), but not 60 minutes postoperatively. All but two patients were discharged shortly after the measurement at 60 minutes, because of pain in one and an attack of asthma in the other. Balance also returned to normal within an hour. CONCLUSION: Objectively measured postural stability and subjectively assessed balance return to normal within 60 minutes after inguinal herniorrhaphy under local infiltration anaesthesia, thereby permitting early discharge.

Adult↗

PubMed1986

A computer-aided system to evaluate postural stress in the workplace.

Stress caused by awkward working posture of the trunk and shoulders can result in fatigue, musculoskeletal disorders and nerve entrapment syndromes. To aid in evaluating the relationship between work activities and postural stress, a computer-aided system was developed. This system produces a detailed description of work tasks and a continuous record of trunk and shoulder activity on the same time scale. The system was used to evaluate postural stresses on a case study job in an automobile assembly plant. The results of the postural analysis were used to identify specific causes of postural stress and to develop recommendations for changes in work station equipment and methods to reduce stress.

Diagnosis, Computer-Assisted↗

PubMed2005

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

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

Biophysics↗

PubMed1995

Errors in prolonged electrical impedance measurements due to electrode repositioning and postural changes.

Long-term electrical impedance measurements are affected by specific errors. Electrode failure, changes in its impedance due to aging, and postural changes are among the most important. We analyse errors due to electrode replacement and body postural changes. Electrode replacement errors can cause impedance changes up to 5% of basal value. This is one of the most important factors in data reproducibility. Body postural changes also contribute to impedance variations. We have proposed the use of a reference position to carry out impedance measurements as the one that shows the smallest impedance sensitivity to postural changes. In general, we observed that this is achieved with arms and legs slightly separated from the body. We propose the use of a ratio of impedance at two different frequencies to discern the origin of impedance changes, whether from physiological phenomena or postural errors.

Adult↗

PubMed1980

Postural hypotension in old age: is it a disorder of the nervous system or of blood vessels?

Beat to beat variation, postural changes in blood pressure and thresholds for vibration sense were measured in 10 young adults and 186 old people living at home. There was a reduction in beat to beat variation, but and increase in postural changes in blood pressure and thresholds for vibration sense in the elderly. Within age and sex groups, there was no correlation between beat to beat variation, postural changes in blood pressure and thresholds for vibration sense, but a strong positive correlation between postural changes in blood pressure and lying systolic pressures. This suggests that, in old age, a change in the structure of the vascular tree may be more important than autonomic dysfunction, as a determinant of postural hypotension.

Adult↗

PubMed2006

Effectiveness of fingertip light contact in reducing postural sway in older people.

BACKGROUND AND OBJECTIVE: haptic cues from fingertip light touch (LT) with a stationary surface reduce postural sway even at non-mechanically supportive force levels. Aim of this study was to determine the effects of LT on postural sway in older compared with younger persons. SUBJECTS: twenty young (age 20-29, mean 23.9 + 2.5) and 20 older participants (age 65-83, mean 74.3 + 6.4). METHODS: subjects stood in the semi-tandem position on a firm surface, and their postural sway was quantified using a force platform. Experimental trials, randomised across subjects, included two sight conditions (vision and no vision) and three contact conditions (no touch, NT; light touch, LT; and force touch, FT). The measured parameters were the length and the area of centre of pressure sway (COP-L and COP-A) and the mean velocity of COP displacements in the anterior-posterior (COP-AP) and medial-lateral (COP-ML) direction. RESULTS: for all variables, the analysis showed significant differences between contact conditions, sight conditions and age. Contact-age interaction was significant between NT and LT conditions, with older participants showing greater decrease in postural sway than younger participants, but not between FT and LT conditions. CONCLUSIONS: results indicate that the effectiveness of LT in reducing postural sway may be greater in older than in younger persons, perhaps because in older persons haptic cues from upper extremity might counterbalance sub-clinical sensory loss in the lower extremities. This finding supports the hypothesis that older people may sometimes use a walking aid as an informative device and suggests that during balance training external aids should not be used.

Adult↗

PubMed1994

Effect of age on the hemodynamic response to posture in nonelderly hypertensive patients.

The objective of this study was to assess the effects of age on the hemodynamic response to a change in posture in essential hypertension. Invasive hemodynamic measurements were performed in the supine and sitting position in 110 men, aged 16 to 64 years, in whom cardiovascular complications were virtually excluded. The change of systolic and diastolic intraarterial pressure, from 153/83 mm Hg after 30 min of supine rest to 156 (P < .05)/92 (P < .001) mm Hg after sitting for 10 min, was not significantly (P > .10) related to age. Heart rate (+9 beats/min) and systemic vascular resistance (+4.6 mm Hg/L/min) increased (P < .001) on sitting; cardiac output (-1.7 L/min), stroke volume (-31 mL), and pulmonary capillary wedge pressure (-2.1 mm Hg) fell (P < .001). Whereas the postural changes of heart rate (P < .01), cardiac output (P < .001), stroke volume (P < .001), and wedge pressure (P = .06) were less pronounced in older than in younger patients, the increase of systemic vascular resistance was not related to age (P > .10). The slopes of the postural changes of heart rate and of systemic vascular resistance differed significantly (P = .01). The results were not confounded by the level of blood pressure or weight. In conclusion, the smaller postural falls of cardiac output, stroke volume, and wedge pressure in older patients suggest less thoracic blood volume displacement to the lower parts of the body, possibly resulting from a lesser peripheral venous distensibility. The increase of heart rate in response to the upright posture is less pronounced at older age, whereas the reflex control of the peripheral vasculature is preserved and blood pressure maintained.

Adolescent↗

PubMed1980

Anticipatory postural reflexes in Parkinson's disease and other akinetic-rigid syndromes and in cerebellar ataxia.

We have examined anticipatory postural responses in calf muscles (triceps surae) in response to a small pull to the arm in standing subjects. This stimulus normally evokes a brisk automatic compensatory contraction of the calf muscles. This is not due to calf muscle stretch, for leg movement occurs after the response has appeared. It appears to be driven centrally by input produced by the pull to the arm. Such anticipatory postural responses were present in every one of the 50 normal subjects studied, but were absent or greatly reduced in many patients with Parkinson's disease when compared to age-matched normal subjects, particularly in those exhibiting postural instability. However, a normal anticipatory postural response was elicited in four patients with progressive supranuclear palsy and in a single patient with an akinetic rigid syndrome due to cerebrovascular disease. Cerebellar truncal ataxia only depressed the response in severe cases. We conclude that although these responses may not be necessary to maintain balance, they may be employed in fine adjustment of posture.

Cerebellar Ataxia↗