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At least 19 recordsLinked to original sources
PubMed1978

Measurement of lip posture and interaction between lip posture and resting face height.

A method for measurement of lip incompetence is described. Electromyographic techniques were used to obtain relaxation of the muscles of the lip and of a jaw elevator muscle. Standardized photographs were taken of the subject's profile, from which lip separation and face height were measured. Variation was found in successive measurements of lip posture, some of which appeared to depend upon mandibular posture. With the teeth in occlusion, lip separation was reduced. Active maintenance of lip contact by the subject was often associated with a reduction in lower face height, which may have been a direct consequence of the lip muscle activity, or of jaw elevator activity facilitating the lip closure.

Adolescent↗
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↗
PubMed1977

A short essay on posture and movement.

Certain statements concerning the relation of posture and movement which have become traditional are re-examined--in particular, the statement 'Movement (that is, pysiological movement) consists of a series of postures. The theme of the essay is the posture--that is, postural activity--should be regarded as a function in its own right and not merely as a component of movement and, secondly, that expressions such as a' series of postures' or 'a change of posture' are not valid as definitions of physiological movement is general, but describe only movement which is part of the postural function. Voluntary movement consists of much more than a series of postures and its significance, ordinarily, is not postural.

Brain↗
PubMed1975

Postural changes of plasma renin activity after renal transplantation.

1. Postural changes of plasma renin activity (PRA) before and after the administration of a beta-blocking agent (oxprenolol) were studied in nine patients with renal homotransplantation and in ten normal subjects. 2. In normal subjects PRA always increased during upright posture without any correlation with postural changes in mean arterial pressure. Oxprenolol reduced the postural increase of PRA. 3. A postural increase of PRA could be detected as early as 20--25 days after renal transplantation, and appeared with increasing frequency as time elapsed. 4. There was a significant inverse correlation (r = -0.794, P less than 0.001) between the postural changes of PRA and those of mean arterial pressure. 5. These results suggest that in patients with renal homotransplantation the postural increase of PRA can only partly be due to circulating catecholamines or the sympathetic nervous system and may be explained by inverse changes in the mean arterial pressure.

Adolescent↗
PubMed1978

Postural equilibrium in adolescent idiopathic scoliosis.

Postural equilibrium has been quantified by stabilometry in 57 patients with adolescent idiopathic scoliosis aged 10-16 years. Treatment was required in 39 cases whereof 18 were placed under observation only. The control group comprised 32 healthy children of the same age. An experimental design was made to vary the degree of difficulty of upright standing in four different test situations. The postural sway was analysed in the sagittal and lateral direction as well as in the area of total sway. The scoliotic patients had a significantly poorer postural control compared with the healthy children in all the tests. The difference was most pronounced in tests in which the proprioceptive functions were most important for maintaining the postural equilibrium. The left convex patients had quantitatively more pronounced reactions than the right convex patients. Patients with small curvatures, i.e., patients placed under observation only, had significantly increased postural sway compared with patients with more severe deformity. This fact, together with findings in patients with double primary curvatures, and the results of the study of brace effects, indirectly indicate the possibility of a postural disequilibrium as a contributory causative factor in adolescent idiopathic scoliosis.

Adolescent↗
PubMed1978

Locomotion and posture in Ateles geoffroyi and Ateles paniscus.

The locomotor and postural behavior of Ateles geoffroyi and Ateles paniscus was studied in Panama and Surinam. Ateles locomotion can be divided into five patterns on the basis of limb usage: quadrupedal walking and running, suspensory locomotion, climbing, bipedalism and leaping. The first three are commonly used in both locomotion during travel and locomotion during feeding, but climbing (especially 'horizontal climbing') is the most important pattern during feeding. Most Ateles locomotion takes place on twigs and branches, with twigs playing a greater role in feeding than in travel. Feeding postures are mainly suspensory and seated, short resting postures are suspensory, seated and standing, and long resting postures are almost entirely seated and reclining. Twigs are the most important supports in feeding postures, but branches are much more important in resting postures. The results of this study indicate that the quadrumanous climbing, forelimb-dominated locomotion during feeding that FLEAGLE considers the primary hominoid adaptation is also characteristic of Ateles.

Animals↗
PubMed1978

Postural sway in amputees and normal subjects.

The postural sway of amputees was investigated quantitatively in fifty patients with above-the-knee amputations and in twenty-nine patients with below-the-knee amputations. The factors evaluated were: (1) the mean speed of sway: (2) the range of movement in the sagittal and coronal planes; and (3) the dependence on vision as indicated by the ratio of eyes-open to eyes-closed values. The results demonstrated that in amputees there is an increased dependence on vision for maintenance of the erect posture. Postural sway in patients with below-the-knee amputations was found to be significantly greater than that in those with above-the-knee amputations. Postural sway increased with age; but the visual dependence for the control of postural sway was independent of age.

Age Factors↗
PubMed1979

The pathogenesis of hyperadrenergic postural hypotension in diabetic patients.

Patients with diabetes generally exhibit normal plasma catecholamine responses to standing. Some have blunted norepinephrine responses and postural hypotension-hypoadrenergic postural hypotension due to classic diabetic adrenergic neuropathy. Others, including some with postural hypotension, have exaggerated norepinephrine responses to standing. In order to clarify the pathogenesis of this hyperadrenergic state which occurs in a subset of diabetic patients, we studied aldosterone secretion, vascular and metabolic responsiveness to the administration of norepinephrine, and intravascular volumes in four diabetic patients who were selected for their exaggerated plasma norepinephrine responses to standing. Three of the four patients also exhibited (hyperadrenergic) postural hypotension. None of the hyperadrenergic diabetic patients had evidence of hypoaldosteronism or vascular resistance to norepinephrine, but all four patients had subnormal red blood cell masses and the mean (+/-SE) red blood cell mass (13.1 +/- 1.0 ml/kg) was approximately half of that of age- and sex-matched diabetic controls (26.5 +/- 2.7 ml/kg, p less than 0.01). Thus, intravascular volume contraction, specifically a reduction in the red blood cell mass, may play an important role in the pathogenesis of hyperadrenergic state observed in a subset of diabetic patients and in the pathogenesis of hyperadrenergic postural hypotension in affected diabetic patients.

Acetoacetates↗
PubMed1978

Postural and kinetic coordination following cortical stimuli which induce flexion movements in the cat's limbs.

The relationship between movement and the postural adjustment associated with it has been studied following flexion movements of a limb induced by cortical stimulation in chronically implanted cats. Variations in the vertical force exerted by each limb, as well as the displacement of the centre of gravity (projected onto the plane of stance), were investigated. It was established that: The pattern of postural adjustment observed in these conditions is diagonal; that is to say, flexion of one limb is accompanied by diminution in the vertical force exerted by the diagonally opposite limb and an increase in the force exerted by the other two. The displacement of the projected centre of gravity is sterotyped during the first phase of variation in forces. Its extent may be considered as an index of the efficiency of postural adjustment. The study of the latencies of the changes in force indicates, at least in the case of hindlimb movements, that postural adjustment is an active phenomenon and does not arise passively from the interplay of purely mechanical forces. In the same conditions, an analysis of the time course and latency of recorded changes in force indicates that postural adjustment is not triggered reflexly by the disequilibrium brought about by movement but is a result of a central nervous command.

Animals↗
PubMed1978

Influence of pyramidotomy on limb flexion movements induced by cortical stimulation and on associated postural adjustment in the cat.

Flexion movements induced by cortical stimulation and the associated postural adjustments in bilaterally pyramidotomised cats have been studied by means of an apparatus which measures separately the changes of force under each limb in the upright position of the animal. The results show: (1) The general motor behaviour of the animal is not affected by the lesion. The principal deficit is loss of tactile placing reaction in the forelimbs; there also appears a state akin to a vestibular syndrome when a light restraining harness is placed around the back and chest. (2) Stimulation of the motor cortex continues to evoke flexion movements of the contralateral limbs together with associated postural adjustment. Coordination between movement and postural adjustment is generally similar to that observed before pyramidal section, and response thresholds are unchanged. (3) Measurements reveal great quantitative modification both of the movement and the postural adjustment after the lesion. Weight shift latencies are increased and more dispersed in time, while the weight shifts themselves are reduced in amplitude and speed. (4) All these changes are more marked in the case of forelimb, rather than hindlimb, flexion, emphasising the greater degree of pyramidal influence on forelimb activity in the normal animal. (5) The results as a whole underline the ability of non-pyramidal systems, under the control of the motor cortex, to bring about both limb flexion and the associated postural adjustments in the absence of the corticospinal pathway.

Animals↗
PubMed1979

Changes in canine postural control after injury to anterior vermal cerebellum.

For a preliminary exploration of cerebellar influences on postural control, dogs were trained to stand quietly erect. Posture was perturbed by sinusoidal movement of the supporting table while the dogs were sighted and while they were blindfolded or stimulated by sinusoidal optokinetic stimuli. Postural responses were evaluated by measuring the relative amplitude of pelvis movement over a series of perturbing frequencies; frequency response descriptions were derived. Lesions of the cerebellar vermis in 3 dogs involved the cortex of lobules V and VI, of lobules IV, V and VI, and of lobules IV--VII plus damage to the medial portion of nucleus fastigius. The two smaller lesions degraded the animal's tracking ability under all three conditions temporarily with extensive but incomplete compensation in 14--21 days. The larger lesion effectively and permanently eliminated the animal's ability to track table or visual field motion. Elimination of visual cues by blindfolding or perturbing the posture with optokinetic stimuli significantly exaggerated the control deficiencies produced by the lesions. It is concluded that the visual input to the cerebellar vermis finds expression through postural control channels.

Animals↗
PubMed1976

[Effect of ablation of the motor cortex or the cerebellum on postural-kinetic coordination in the cat].

1. A cat, restrained in a hammock, stands with its feet on supporting trays each furnished with strain gauges to measure the isometric upthrust. Placing reactions are elicited by contact of the left or right forelimb with a moving tray. The placing movement is preceded and accompanied by a postural adjustment characterized by an increase of the upthrust exerted by the opposite forelimb. 2. After ablation of the motor cortex on one side, the placing movement of the contralateral forelimb is abolished for the first few days after the operation and thereafter is delayed. However, the postural adjustment of the ipsilateral forelimb persists, with the same range of latencies as before the operation. 3. After unilateral motor cortical ablation, the contralateral forelimb still takes part in the postural adjustment associated with the placing movement of the other forelimb. 4. In two cats which had 2 years earlier undergone a total cerebellectomy, the placing movement was lacking or appeared with a long delay, whereas a postural adjustment of the other forelimb could be observed, although reduced. 5. The results indicate that the nervous structures responsible for the movement and for the associated postural adjustment are separate but partially linked.

Animals↗
PubMed1977

Ictal tonic postural changes and automatisms of the upper limb during epileptic parietal lobe discharges.

Tonic postural changes of the upper limb accompanied by epileptic parietal lobe discharges are not well known. The authors report 3 such cases. In the 3 patients, a total of 18 spontaneous seizures were recorded, 12 by telemetry, from either scalp electrodes or stereotactically implanted electrodes. Of these 18 seizures, 14 included tonic postural changes of the upper limb accompanied by a contralateral parietal discharge. Combining these 3 cases with the 4 such cases in the literature, the authors found that the clinical pattern consisted of a tonic postural change in one upper limb associated with automatisms of the opposite upper limb. It was also found that the same patient might have automatisms involving the upper limb in some seizures and upper limb postural changes in other seizures, both accompanied by the same electrical discharge. It is concluded that tonic postural changes and automatisms in the upper limb may be interchangeable.

Adult↗
PubMed1977

Postural effects on muscle nerve sympathetic activity in man.

1. Pulse-synchronous bursts of multi-unit sympathetic activity (MSA) were recorded in peroneal muscle nerve fascicles in eight healthy subjects when lying, sitting and standing. The sympathetic activity was quantitated by counting the number of bursts in the mean voltage neurogram/min. Postural changes were analysed by considering the total activity to be a product of the number of bursts in relation to the number of heart beats (burst incidence) and the heart rate.2. In lying there were large interindividual differences in total activity, but for all subjects the activity increased when going from lying to sitting and from sitting to standing. With a few exceptions the increase between the lying and sitting postures was associated with an increase in both burst incidence and heart rate whereas between the sitting and standing postures there was an increase in heart rate but on the average no change in burst incidence.3. When going from lying to sitting or from sitting to standing the magnitude of the change in burst incidence was inversely related to the initial burst incidence so that subjects with low initial values usually showed greater increases in burst incidence than subjects with high initial values. Some subjects with high initial values decreased their burst incidence.4. With changes in postures there was an inverse linear relationship between the fraction of the change in MSA associated with a change in burst incidence and the fraction associated with a change in heart rate. An increase in total activity could be obtained by changing only burst incidence, by increasing heart rate without changing burst incidence, or by appropriate changes in both parameters. The slope of the regression line was -0.53 indicating that for adequate postural compensation fewer additional bursts were required when the compensatory response involved an increase in heart rate rather than an increase in only burst incidence.5. It is suggested that an impairment of the ability to regulate heart rate will make subjects with high burst incidence in the lying position orthostatically more vulnerable than those with low burst incidence.6. Shortly after standing up one subject developed bradycardia and subsequently fainted. The nerve recording was maintained until the subject collapsed. During the initial bradycardia no sympathetic bursts occurred suggesting that the syncope was associated with an interruption of normal baroreflex feedback between blood pressure and sympathetic outflow.

Adult↗