Search PubMedSearch

SEARCH · Search PubMed

Results for “Leg”

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 37 records · Page 2Linked to original sources

Changes in the metabolism of the shivering hind leg of the young ox during several days of continuous cold exposure.

The effect of 4 days of continuous exposure to a cold environment on blood flow in, and oxygen and energy substrate uptake by the shivering hind leg has been studied in young steers. The animals shivered throughout the period of cold exposure and total oxygen consumption (total VO2) remained 40-50% greater than VO2 during thermoneutrality. Leg blood flow (leg Q) and oxygen uptake (leg VO2) increased two- and four-fold respectively on the first day of cold. Both had declined significantly by the final day, leg Q to a level 37% greater than, and leg VO2 to about double, pre-cold levels. The change in the relationships of leg Q and leg VO2 to total VO2 was examined by linear regression analysis, which suggested that the changing contribution of leg VO2 to total VO2 was entirely due to changes in leg Q, rather than in the arteriovenous difference in blood oxyhaemoglobin saturation across the leg. The net uptakes by the leg of free fatty acids (FFA), acetate, glucose and lactate all increased on the first day of cold. Both glucose and acetate uptakes were greater on day 4 than on day 1 in the cold, in spite of the lower leg VO2, but net uptakes of FFA and lactate were considerably lower. The decrease in net uptake of FFA is attributed mainly to an increase in the rate of lipolysis and release of FFA from fat depots in the leg, because of the associated progressive increase in the release of glycerol and oleic acid from the leg. The molar ratios of net carbohydrate substrate, acetate and FFA uptakes to leg VO2 are compared. The results suggest that tissues other than the leg muscles become increasingly important as sites of heat production, and that there are changes in the utilization of glucose, acetate and FFA by shivering muscle, during prolonged cold exposure.

Acetates

Acute cold exposure and the metabolism of blood glucose, lactate and pyruvate, and plasma amino acids in the hind leg of the fed and fasted young ox.

1. Young steers were fed either 3-4 or 20 h before exposure to a thermoneutral or a moderately cold environment. Measurements were made of total oxygen consumption (total V 0-2), respiratory quotient (rq), blood packed cell volume (PCV), and hind-leg blood flow (leg Q) and oxygen uptake (leg VO-2). The arteriovenous differences in whole blood glucose, lactate and pyruvate, and individual amino acid and urea concentrations across the leg were also measured. Net exchange and fractional uptake of these metabolites by the leg were calculated from these results. 2. Cold exposure doubled total VO-2, significantly decreased RQ and significantly increased PCV. Leg Q and leg VO-2 increased 3- to 5-fold and 4- to 13-fold respectively in both feeding groups. Arterial blood glucose increased slightly but significantly in both 20 h- and 3 h-fed steers. There was a substantial increase in mean net leg uptake of glucose in both feeding groups. This was much greater in the 20 h-fed group because of the significant increase in fractional uptake occurring only in this group. Cold did not significantly affect arterial blood lactate or pyruvate levels, but the net leg output of lactate found in both feeding groups in thermoneutrality was increased in the 20 h-fed steers, and reversed to a net uptake in the 3 h-fed animals. Cold caused a small but significant decrease in the total plasma amino acid level in the 20 h-fed but not in the 3 h-fed group; individual amino acid levels or leg uptakes were not affected. 3. Feeding before the experiment caused a significant increase in RQ. Leg Q, leg uptake of glucose and leg output of lactate increased after feeding in the thermoneutral environment only. Arterial pyruvate increased significantly, but net leg output was not significantly affected by feeding. Arterial plasma concentration of several individual, but not of total amino acids, increased significantly in both environments, and the net output of many individual amino acids in the 20 h-fed steers was decreased or reversed to a net uptake in the 3 h-fed group in thermoneutrality only. 4. The results suggest that blood glucose could be a significant fuel for oxidation in shivering skeletal muscle in young steers, and that output of amino acids from skeletal muscle could not contribute significantly to this increased glucose supply by hepatic gluconeogenesis.

Acclimatization

Work capacity, muscle strength and SDH activity in both legs of hemiparetic patients and patients with Parkinson's disease.

In recent muscle metabolic studies, patients with moderate upper motor neuron lesions showed marked difficulty in performing an equal submaximal work load (bilaterally) in two-legged exercise. For a better evaluation of these patients, studies were performed on each leg separately. Six patients with Parkinson's disease and six with moderate hemiparesis were studied. During one-legged submaximal and maximal exercise heart rate, oxygen uptake, and blood lactate were determined. Maximal voluntary contraction in knee and ankle flexion and extension for each leg was measured. Succinate dehydrogenase (SDH) activity in the thigh muscles was determined. During submaximal exercise, oxygen uptake, heart rate and blood lactate increased more in the paretic leg of hemiparetic patients and in the more affected leg of the Parkinson patients. In hemiparetic patients maximal voluntary contraction of flexors and extensors of the knee was significantly reduced in the paretic leg but was reduced even in the nonparetic knee flexors. SDH activity was very low in both legs in all patients and lowest in the paretic and more affected leg, respectively. It is concluded that (a) the general muscle inactivity per se, secondary to the neurological disorder, may lead to a reduced work capacity; (b) the increased heart rate and blood lactate level seem to be correlated to the relative exercise level of each leg; and (c) in patients with impaired muscle function of one or both legs, evaluation of each leg separately with regard to work capacity and muscle metabolism is of value.

Adult

Regeneration of peripheral nerves to supernumerary legs in cockroaches.

1. Clusters of legs were grown from metathoracic coxae of the cockroach. Legs of a cluster had different segmental origins, sizes, and orientations. 2. Regenerating metathoracic nerves tended to enter the nearest leg, and to a lesser extent of the largest leg, but showed no significant tendency to penetrate metathoracic rather than prothoracic legs, or normally oriented rather than abnormally oriented legs. 3. Movements of legs were evoked by nerve stimulation significantly more often in nearest, largest, and normally oriented legs, but were equally frequent in prothoracic and metathoracic legs. 4. Close proximity of peripheral nerves is not required for the differentiation of the legs, since nerves were visible in the legs only at the later stages of their development, and many of the legs were apparently nerve innervated.

Animals

Contralateral influence on recruitment of curarized muscle fibres during maximal voluntary extension of the legs.

The force of maximal voluntary contraction (MVC) was compared during extension of one leg alone and during simultaneous extension of both legs. In 6 subjects MVC of two legs extension was 75 +/- 3.6 (S.E.)% of the sum of the single one leg MVC. This may indicate a reduced muscle fibre involvement during two leg extension as compared with one leg extension. We investigated the possibility that either red (type I) or white (type II) muscle fibre recruitment was restricted during two leg extension. The neuromuscular transmission in the two types of fibres was partially blocked with d-tubocurarine (dtc) or decamethonium (C10) for either type I or II, respectively. In 5 subjects receiving dtc the ratio between the reduced two leg and one leg extension forces (75 +/- 2.3%) did not change. During administration of C10, however, this ratio decreased by 16 +/- 3.1%. Partial blocking with dtc caused a two component curve during tension development with a first maximum at 0.22 s, and another maximum at 1.03 s of a 3 s attempt to reach MVC. During partial blocking with C10 results in muscle contractions where a relatively large amount of type I muscle fibres are contributing to the force developed. The experiment suggests that type I fibre recruitment is restricted during severe static exercise in normal muscles. Furthermore, it demonstrates that fibre recruitment can vary in the same muscle function performed with one leg or two legs.

Adult

The painful chronic anterior lower leg syndrome. A prospective clinical and experimental study.

A presumed painful chronic anterior lower leg syndrome was diagnosed in 51 patients (73 legs), 30 women and 21 men, aged 11 to 70 years, over a 2-year period. The duration of the syndrome varied from 1 month to 10 years. The patients' main complaint was pain when walking located in the medial ventral muscle compartment of the lower leg. In addition 10 of the patients (15 legs) had leg pain at rest as well and 12 (15 legs) had paresis of the extensor muscles. Thirty-four paired intracompartmental pressure recordings with the wick technique in 6 patients suggest that the more severe the syndrome the lower the pressure in the tibialis anterior muscle. Blind diathermic fasciotomy in 25 patients (36 legs) with a typical history relieved the pain and paresis completely or partly in 33 (92 per cent) out of 36 legs. No postoperative complications worth mentioning were observed. It is concluded that: 1) a chronic painful anterior lower leg syndrome should be suspected in patients with pain on walking and at rest located in the ventral part of the lower leg; 2) intracompartmental pressure measurements seem to be of little preoperative diagnostic value in non-selected patients; 3) blind diathermic fasciotomy of the anterior, medial compartment of the lower leg, including the extensor retinaculum, gives relief from pain and paresis in most patients with a typical history.

Adolescent

Effects of leg exercise on insulin absorption in diabetic patients.

To examine the effects of leg exercise on insulin absorption from various injection sites, 125I-labelled rapid actin insulin (9 units) was injected subcutaneously into the leg, arm or abdomen of patients with insulin-dependent diabetes before one hour of intermittent leg (bicycle) exercise and on a resting, control day. Insulin disappearance from the leg increased by 135 per cent during the first 10 minutes of leg exercise (P less than 0.05) and remained 50 per cent above resting levels after 60 minutes (P less than 0.02). Leg exercise had no effect on insulin disappearance from the arm, but insulin disappearance from the abdomen was reduced during the post-exercise recovery period (P less than 0.02). As compared to leg injection, arm or abdominal injection reduced the hypoglycemic effect of exercise by 57 per cent (P less than 0.02) and 89 per cent (P less than 0.005), respectively. Leg exercise accelerates insulin absorption from the leg. Arm or abdominal injection avoids this acceleration during leg exercise and reduces exercise-induced hypoglycemia.

Abdomen

Forces applied to cranks of a bicycle ergometer during one- and two-leg cycling.

An examination was made of the comparability of one- and two-leg exercise performed pedaling a stationary bicycle ergometer. The pattern of force exerted on both cranks was examined by means of a specially adapted ergometer which is described. The mean of the peak force in each cycle (MPF) was linearly related to work load (W) in both forms of exercise, and if account was taken of the doubled work output in two-leg cycling there was no significant difference between the MPF/W relationships; these are given by the equations one-leg: MPF (kg) = 11.23 + 0.065 (W in kpm/min) two-leg MPF (kg) = 10.76 + 0.032 (W in kpm/min). Calculation from the force records of the work performed on the cranks (WCR net) showed good agreement (r = 0.98, P less than 0.001) with the work load set on the ergometer. Analysis of the proportion of work done in leg extension and flexion phases of cycling revealed no differences between one- and two-leg exercise or between the right and left legs. The majority (approximately 80%) of Wer net being performed in leg extension is described by: Wer net (extension)) = 10.6 +/- 0.8 (W cr net total). In one-leg exercise (W greater than 900 kpm/min) the variation in rotation speed during a normal cycle ranged from +20 to --30% of the mean speed compared with +/- 10% in two-leg exercise.

Adult

[Adult leg development of Tenebrio molitor: I. Experimental analysis of the restoration process during morphogenesis (author's transl)].

The leg of the last instar larva, and especially the pharate pupa, of Tenebrio molitor (Coleoptera) shows considerable restoration ability. Restoration refers to the regeneration of leg structures removed during the last larval instar. This process involves only those tissues adjacent to the cut surface. At each level of the leg, amputation before a characteristic time leads to the restoration of a complete leg, but thereafter the new segments formed are hypomorphic or just lobes. After an amputation close to the pupal ecdysis, fragments are obtained, and these incomplete structures show that the restoration process has ceased. Just before the pupal ecdysis the leg is withdrawn from the cuticle, so a very late amputation does not effect the leg tissue and a complete pupal and adult leg is formed. The whole of the larval leg participates in adult leg morphogenesis, and histological techniques demonstrate a great correspondence between larval and adult leg segments. The larval trochanter, however, forms the adult trochanter and the proximal part of the femur. The larval tibia forms the adult tibia plus tarsus, except for the adult claws which develop from the larval tarsal claw.

Amputation, Surgical

Difference in leg length in children with coxa plana during and after treatment using unilateral unloading.

In unilateral coxa plana a shortening of the affected leg can often be found. This shortening affects not only the caput-collum part of the femur but also the other parts of the femur and the tibia. In this study, however, the immobilization of the affected leg seemed to be the main reason for the observed difference in the leg length. Children who had not unloaded their affected leg as carefully as they should proved to have a smaller difference in leg length than those who had unloaded their affected leg according to the instructions. On the other hand compensatory growth of the affected leg was found when both legs were again taking weight. The difference in the leg length was significantly reduced one year after the completion of the treatment.

Child

Effects of exercise therapy on total and component tissue leg volumes of patients undergoing rehabilitation from lower limb injury.

Anthropometric and X-ray data were collected on 20 young male patients undergoing a systematic programme of exercise therapy following fracture of the leg and consequent immobilization for 25--254 (mean 117) days. Estimates of total leg volume, calculated from X-ray or from anthropometric measurements, were essentially interchangeable in both the injured and uninjured legs. A procedure for estimating muscle volume from total leg volume is given. At the start of rehabilitation, muscle volume was significantly smaller (860 ml, 16 per cent) in the injured than in the uninjured leg. By the end of rehabilitation (mean 50 days) the injured leg had siginficantly increased by 360 ml (8 per cent) over its initial volume, and the uninjured one had increased but not significantly (120 ml, 2 per cent), so that the injured leg was still approximately 11 per cent (620 ml) small than the uninjured. The initial degree of atrophy and the period of immobilization were not significantly correlated, although the latter showed a negative relationship (P greater than 0.05) with the rate of increase of muscle volume in the injured leg. No significant correlation was found between the ratio of injured/uninjured leg volumes and muscle width measurements at 1/3 subischial, at 12.7 cm above the knee joint space or at the maximum calf. In systematic studies involving atrophy muscle volume must therefore be estimated either by anthropometry or by X-ray measurements.

Adult

[Influence of dihydroergotamine and leg compression on the blood volume in different regions of the body (author's transl)].

After intravenous injection of 99mTc labelled autologous erythrocytes the radioactivity of a definite body-region is proportional to the local blood volume. By whole body scintigraphy it is possible to assess simultaneous changes of blood volume in different interesting regions. By this method the influence of 1 mg dihydroergotamine i.v. was investigated in 10 patients and of compression of both legs by inflatable leg cuffs (Jobst) with pressures of 25 and 40 mmHg (3,3 and 5,3 kPa) in 7 patients. After dihydroergotamine statistically significant decreases of blood volume were found in the legs and arms and increases in the thorax and liver. Over the abdominal region there was a statistically not significant decrease of blood volume. After leg compression a statistically significant decrease of blood volume in the legs and an increase in thorax, liver and abdomen were found. The arms showed a statistically not significant blood volume increase. The blood volume diminishing effect of dihydroergotamine in the legs was 20,4% in average, of a leg compression (25 mmHg=3,3 kPa) 33,4%. Contrary to the general opinion a reduction of blood volume was also found in legs with severe varicosis. The diminution of blood volume is even more intense in such cases than in normal legs. The results after dihydroergotamine are explained by its well known constrictor effect on the capacitance vessels in the extremities.

Abdomen

Influence of beta-adrenoceptor blockade on leg blood flow and lactate release in man.

Nine healthy male volunteers were studied at rest and during exercise before and after acute local beta-blockade in one leg. Oxygen uptake, arterial pressure, heart rate, leg blood flow and arterial-femoral venous differences for oxygen and lactate were determined. In addition, five subjects were studied at rest during adrenaline infusion to test the blockade; in this situation the increase in leg blood flow and decrease in resistance seen in the control leg were prevented in the blocked leg. During exercise, the beta-blockade did not influence leg blood flow. At rest, lactate release was abolished from the blocked leg, and during exercise the release was reduced by 50%. These findings demonstrate that acute betareceptor blockade does not interfere with the exercise-induced vasadilation but has metabolic consequences reflected by a reduction in the release of lactate from the leg.

Adrenergic beta-Antagonists

Central and regional circulatory effects of adding arm exercise to leg exercise.

7 young, healthy, male subjects performed exercise on bicycle ergometers in two 20 min periods with an interval of 1 h. The first 10 min of each 20 min period consisted of arm exercise (38--62% of Vo2 max for arm exercise) or leg exercise (58--78% of Vo2 max for leg exercise). During the last 10 min the subjects performed combined arm and leg exercise (71--83% of Vo2 max for this type of exercise). The following variables were measured during each type of exercise: oxygen uptake, heart rate, mean arterial blood pressure, cardiac output, leg blood flow (only during leg exercise and combined exercise), arterio-venous concentration differences for O2 and lactate at the levels of the axillary and the external iliac vessels. Superimposing a sufficiently strenuous arm exercise (oxygen uptake for arm exercise greater than 40% of oxygen uptake for combined exercise) on leg exercise caused a reduction in blood flow and oxygen uptake in the exercising legs with unchanged mean arterial blood pressure. Superimposing leg exercise on arm exercise caused a decrease in mean arterial blood pressure and an increased axillary arterio-venous oxygen difference. These findings indicate that the oxygen supply to one large group of exercising muscles may be limited by vasoconstriction or by a fall in arterial pressure, when another large group of muscles is exercising simultaneously.

Adult

Effects of training on the physiological responses to one- and two-leg work.

The effects of training resulting from one-leg exercise on a stationary bicycle ergometer have been studied. Seven subjects were habituated to one- and two-leg progressive exercise tests on 11 successive days and were then trained for 60 min-day-1 (30 min each leg) 3 times per wk for 5-6 wk at approximately 80% of their one-leg VO2 max. VE max increased (P less than 0.05) by approximately 14 1-min-1 and VO2 max by approximately 0.34 1-min-1 (+14%; P less than 0.05) in one-leg exercise. This latter increase was not, however, reflected in the two-leg VO2 max which only increased 145 ml-min-1 (4.7%). It was concluded that training is specific and in one-leg work the phenomenon is mainly peripheral in origin, but in two-leg work the limitation to maximal exercise is still provided by the capacity of the central cardiovascular system to transport oxygen to a given effective muscle mass.

Adult

Effects of arm training on retention of training effects derived from leg training.

This study examined the effects of arm training on retention of training effects produced by leg training. Thirteen adult male subjects leg trained on bicycle ergometers for 8 weeks. During the subsequent 4 week control period group AT (N = 4) arm trained by cranking an ergometer, group DT (N = 4) discontinued training and group LT (N = 5) continued leg training. Metabolic response to maximal and submaximal (80% initial Vo2max) leg work was observed before (Test I) and after (Test II) the 8 week leg training program and at the conclusion of the control period (Test III). With the initial 8 weeks of leg training Vo2max and maximal Ve increased while Vo2, HR, Ve and blood lactate decreased during submaximal work (p less than .05). R was decreased during both maximal and submaximal work (p less than .05). Analysis of covariance of the Test III means (Test II as covariate) yielded significant (p less than .05)F-ratios for Vo2max and R at Vo2max. Post hoc testing indicated that Vo2max was greater in LT than in AT or DT but that there was no difference between AT and DT. R at Vo2max was greater in DT than in LT or AT. These data suggest that arm training does not significantly affect the deterioration in metabolic response to leg work which occurs with cessation of leg training.

Adolescent

The incidences of leg and foot abnormalities in Wrolstad White turkeys.

The leg and foot abnormalities of a flock of 911 Wrolstad White turkeys were described and were analyzed statistically to determine the relationship of the incidences of leg and foot abnormalities to sex and body weight of the turkeys. Body weight and a visual observation of the condition of legs and feet of each turkey were recorded at the age of nearly 12 weeks. The sex of each turkey had been recorded at one day of age. Based on chi-square contingency tables, the incidence of the leg and foot abnormalities was related to sex. The male turkeys were far more likely to experience leg and foot abnormalities than were the females. The incidence rate of severe leg and foot abnormalities was 16.1% for the males and 4.8% for females. The incidence of leg and foot abnormalities was not related to weight per se. The light turkeys of either sex were just as likely as the heavy turkeys of the same sex to have leg and foot abnormalities.

Animals

The genesis of the pulse contours of the distal leg arteries in man.

In order to clarify the genesis of the human pressure and flow pulse contours of the distal leg arteries, in particular the posterior tibial artery, pulse recordings were performed with transcutaneous techniques under normal conditions and in the state of strong vasodilatation (reactive hyperaemia) in the distal parts of the lower legs. From the experimental results it is concluded that the contour of the incident pressure wave arriving in the leg arteries is very similar to the pressure pulse contour of the abdominal aorta, while the resulting contour in the leg arteries is determined by this incident wave and superimposed reflected waves. The latter arise from positive reflection in the periphery of the lower legs. The travel in retrograde direction, are reflected negatively in proximal regions, particularly in the abdominal aorta, and appear again, with opposite sign, in the leg arteries. In addition, retrograde waves reflected positively at the aortic valve and then traveling in antegrade direction also influence the pulse contours. By considering this wave travel, the genesis of the characteristic contours of the pressure and flow pulses of the lower leg arteries is explained in a satisfactory way. This is demonstrated by a simplified graphical pulse construction as well as by the calculation of pulse contours on the basis of a theoretical tube model of the arterial system with the aid of a digital computer. The results of these calculations are discussed with respect to the findings of previous investigators who used analog and digital models of the arterial system.

Adolescent